Light-emitting device and display apparatus

Abstract

To provide a light-emitting device having good characteristics. To provide a tandem light-emitting device in which a first light-emitting layer contains a first fluorescent light-emitting substance, a first organic compound, and a second organic compound, a second light-emitting layer contains a second fluorescent light-emitting substance, a third organic compound, and a fourth organic compound, the difference between the peak wavelength in the emission spectrum of the first fluorescent light-emitting substance and the peak wavelength in the emission spectrum of the second fluorescent light-emitting substance is 30 nm or less, and the first light-emitting layer and the second light-emitting layer are light-emitting layers that emit light in different hues from the light-emitting layer included in at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

Description

Technical Field

[0001] One aspect of this invention relates to an organic compound, an organic semiconductor element, a light-emitting device, a photodiode sensor, a display module, a lighting module, a display device, an electronic device, a lighting device, and an electronic device. Note that this aspect of the invention is not limited to the aforementioned technical fields. The technical field of one aspect of the invention disclosed in this specification relates to an object, method, or manufacturing method. One aspect of the invention relates to a process, machine, manufacture, or composition of matter. Therefore, more specifically, as an example of the technical field of one aspect of the invention disclosed in this specification, examples include semiconductor devices, display devices, liquid crystal display devices, lighting devices, energy storage devices, memory devices, imaging devices, methods for driving these devices, or methods for manufacturing these devices. Background Technology

[0002] The practical application of electroluminescence (EL) devices using organic compounds (also known as organic EL elements) is very active. In the basic structure of these devices, an organic compound layer containing a luminescent center is sandwiched between a pair of electrodes. By applying a voltage to the device and injecting charge carriers, luminescence from the luminescent center can be obtained using the recombination energy of these charge carriers.

[0003] Because the light-emitting device is self-emissive, display devices using this device offer higher visibility compared to liquid crystal displays (LCDs) and do not require backlighting. Furthermore, display devices using this type of device can be manufactured to be thin and lightweight, which is a significant advantage. Moreover, its extremely fast response time is also a key feature.

[0004] Furthermore, because the light-emitting layer of this type of light-emitting device can be formed continuously in a planar shape, surface light emission can be achieved. Since this characteristic is difficult to obtain in point light sources such as incandescent lamps and LEDs, or line light sources such as fluorescent lamps, the aforementioned light-emitting device is highly valuable as a surface light source for illumination and other applications.

[0005] As mentioned above, although display devices and lighting devices using light-emitting devices are suitable for a wide variety of electronic devices, research and development of light-emitting devices with better characteristics is becoming increasingly active.

[0006] In particular, series-connected light-emitting devices have attracted attention due to their ability to achieve high current efficiency.

[0007] Patent Document 1 and Patent Document 2 disclose series-type light-emitting devices with different coating methods.

[0008] [Preliminary Technology Documents] [Patent Literature] [Patent Document 1] Japanese Patent Application Publication No. 2005-317548 [Patent Document 2] Japanese Patent Application Publication No. 2023-161850. Summary of the Invention

[0009] The technical problem that the invention aims to solve One objective of this invention is to provide a light-emitting device with excellent characteristics. Furthermore, one objective of this invention is to provide a light-emitting device with good luminous efficiency. Additionally, one objective of this invention is to provide a light-emitting device with high reliability. Furthermore, one objective of this invention is to provide a light-emitting device with low driving voltage. Finally, one objective of this invention is to provide a light-emitting device with both high reliability and low driving voltage.

[0010] Furthermore, one objective of this invention is to provide a light-emitting device capable of providing a display device with good characteristics. Another objective of this invention is to provide a light-emitting device capable of providing a display device with good luminous efficiency. Another objective of this invention is to provide a light-emitting device capable of providing a display device with good reliability. Another objective of this invention is to provide a display device with low driving voltage. Finally, one objective of this invention is to provide a light-emitting device capable of providing both low driving voltage and good reliability in a display device.

[0011] Furthermore, one objective of this invention is to provide any one of a low-power organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device. Another objective of this invention is to provide any one of a highly reliable electronic device and a lighting device. Finally, one objective of this invention is to provide any one of a novel organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device.

[0012] This invention can achieve any one of the above-described objectives. Note that the description of these objectives does not preclude the existence of other objectives. Note that one embodiment of this invention does not necessarily require achieving all of the above-described objectives. Note that objectives other than those described above can be understood and extracted from the description, drawings, claims, etc.

[0013] means of solving technical problems One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, an intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The intermediate layer is located between the first and second electrodes, the first light-emitting layer is located between the first electrode and the intermediate layer, the second light-emitting layer is located between the intermediate layer and the second electrode, the first electron transport layer is located between the first light-emitting layer and the intermediate layer, and the second electron transport layer is located between the second light-emitting layer and the second electrode. The first light-emitting layer comprises a first fluorescent luminescent material, a first organic compound, and a second organic compound. The second light-emitting layer comprises a second fluorescent luminescent material, a third organic compound, and a fourth organic compound. The difference between the maximum peak wavelength in the emission spectrum of the first fluorescent luminescent material and the maximum peak wavelength in the emission spectrum of the second fluorescent luminescent material is less than 30 nm. Furthermore, the first and second fluorescent luminescent materials exhibit different hues of light emission from the luminescent center material in the light-emitting layer of at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

[0014] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first organic compound and the third organic compound are organic compounds comprising a first polycyclic hydrocarbon and a second polycyclic hydrocarbon, and the second organic compound and the fourth organic compound are organic compounds comprising a third polycyclic hydrocarbon and a polycyclic heteroaromatic ring.

[0015] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first organic compound and the third organic compound are aromatic hydrocarbons.

[0016] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first polycyclic hydrocarbon is the same as the third polycyclic hydrocarbon.

[0017] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first polycyclic hydrocarbon and the third polycyclic hydrocarbon are substituted or unsubstituted anthracene groups.

[0018] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the lowest triplet excitation energy level of the first fluorescent light-emitting material is higher than the lowest triplet excitation energy level of the first organic compound and the lowest triplet excitation energy level of the second organic compound, and the lowest triplet excitation energy level of the second fluorescent light-emitting material is higher than the lowest triplet excitation energy level of the third organic compound and the lowest triplet excitation energy level of the fourth organic compound.

[0019] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein one or both of the first organic compound and the second organic compound, and one or both of the third organic compound and the fourth organic compound, are deuterated organic compounds.

[0020] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the intermediate layer comprises a fifth organic compound having a phenanthroline skeleton and a metal element.

[0021] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second electron transport layer comprises a sixth organic compound having a triazine framework.

[0022] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second electron transport layer further comprises lithium or a lithium compound.

[0023] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first electron transport layer comprises a seventh organic compound having a triazine framework.

[0024] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the seventh organic compound is the same as the sixth organic compound.

[0025] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second electron transport layer has a stacked structure comprising a second electron transport layer located on one side of the light-emitting layer and a second electron transport layer located on one side of the second electrode, and a sixth organic compound is contained in the second electron transport layer.

[0026] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second electron transport layer has a stacked structure comprising a second electron transport layer located on one side of the light-emitting layer and a second electron transport layer located on one side of the second electrode, and a sixth organic compound and lithium or a lithium compound are contained in the second electron transport layer.

[0027] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second electron transport layer comprises an eighth organic compound having a triazine framework.

[0028] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first hole transport layer has a stacked structure including a first hole transport layer 1a and a first hole transport layer 1b in contact with the first light-emitting layer, and the first hole transport layer 1b contains a ninth organic compound having an amine backbone and a polycyclic aromatic ring backbone.

[0029] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the light-emitting device includes a first hole transport layer between the first light-emitting layer and the first electrode, and the first hole transport layer comprises a tenth organic compound having an amine backbone and a polycyclic hydrocarbon backbone.

[0030] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the maximum peak wavelength in the emission spectrum of the first fluorescent light-emitting material and the maximum peak wavelength in the emission spectrum of the second fluorescent light-emitting material are located between 450 nm and 520 nm.

[0031] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first light-emitting center material and the second light-emitting center material are the same material.

[0032] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the intermediate layer includes a first layer comprising a fifth organic compound.

[0033] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first layer comprises lithium or a lithium compound.

[0034] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the intermediate layer further includes a second layer, and the second layer is located between the first layer and the second light-emitting layer.

[0035] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer comprises a 17th organic compound having hole transport properties.

[0036] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer comprises an organic compound having at least one of a halogen group and a cyano group.

[0037] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer comprises an organic compound having at least one of fluorine and cyano groups.

[0038] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer comprises an organic compound having at least one of a halogen group and a cyano group, wherein the number of at least one of the halogen group and the cyano group is 4 or more.

[0039] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer comprises an organic compound having at least one of fluorine and cyano groups, wherein the number of at least one of the fluorine and cyano groups is 4 or more.

[0040] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first electron transport layer comprises an 18th organic compound that does not have a triazine skeleton.

[0041] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first electron transport layer comprises an 18th organic compound having at least one of a pyrimidine framework, an imidazole framework, and an anthracene framework. Furthermore, by having multiple of the above-described frameworks, electron transport properties can be improved or adjusted.

[0042] Another aspect of the present invention is a display device, including any of the light-emitting devices described above.

[0043] Another aspect of the present invention is a display device including a light-emitting device A and a light-emitting device B, wherein light-emitting device A and light-emitting device B are adjacent to each other. Light-emitting device A includes a first electrode A, a second electrode A, an intermediate layer A, a first light-emitting layer A, a second light-emitting layer A, a first electron transport layer A, and a second electron transport layer A. The intermediate layer A is located between the first electrode A and the second electrode A. The first light-emitting layer A is located between the first electrode A and the intermediate layer A. The second light-emitting layer A is located between the intermediate layer A and the second electrode A. The first electron transport layer A is located between the first light-emitting layer A and the intermediate layer A. The second electron transport layer A is located between the second light-emitting layer A and the second electrode A. Light-emitting device B includes a first electrode B, a second electrode B, an intermediate layer B, a first light-emitting layer B, a second light-emitting layer B, a first electron transport layer B, and a second electron transport layer B. The intermediate layer B is located between the first electrode B and the second electrode B. The first light-emitting layer B is located between the first electrode B and the intermediate layer B. The second light-emitting layer B is located between the intermediate layer B and the second electrode A. Between electrodes B, the first electron transport layer B is located between the first luminescent layer B and the intermediate layer B, and the second electron transport layer B is located between the second luminescent layer B and the second electrode B. The second electron transport layer A and the second electron transport layer B are made of the same material. The first luminescent layer A contains a first fluorescent luminescent substance, a first organic compound, and a second organic compound. The second luminescent layer A contains a second fluorescent luminescent substance, a third organic compound, and a fourth organic compound. The first luminescent layer B contains a third luminescent center substance and a fourth luminescent center substance. The difference between the maximum peak wavelength in the emission spectrum of the first fluorescent luminescent substance and the maximum peak wavelength in the emission spectrum of the second fluorescent luminescent substance is less than 30 nm. The difference between the maximum peak wavelength in the emission spectrum of the third luminescent center substance and the maximum peak wavelength in the emission spectrum of the fourth luminescent center substance is less than 30 nm. Furthermore, the first luminescent layer A and the first luminescent layer B, and the second luminescent layer A and the second luminescent layer B are luminescent layers that exhibit different hues.

[0044] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the third light-emitting center material and the fourth light-emitting center material are phosphorescent light-emitting materials.

[0045] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first light-emitting layer A and the first light-emitting layer B emit light at a shorter wavelength than the second light-emitting layer A and the second light-emitting layer B.

[0046] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first fluorescent light-emitting material and the second fluorescent light-emitting material exhibit light emission at a shorter wavelength than the third light-emitting center material and the fourth light-emitting center material.

[0047] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the peak wavelengths of the emission spectra of the first light-emitting layer A and the first light-emitting layer B are shorter than the peak wavelengths of the emission spectra of the second light-emitting layer A and the second light-emitting layer B.

[0048] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the peak wavelengths of the emission spectra of the first fluorescent light-emitting material and the second fluorescent light-emitting material are shorter than the peak wavelengths of the emission spectra of the third light-emitting center material and the fourth light-emitting center material.

[0049] In addition, another aspect of the present invention is a display device having the above-described structure, wherein the first light-emitting layer B further comprises an 11th organic compound and a 12th organic compound, and the second light-emitting layer B further comprises a 13th organic compound and a 14th organic compound.

[0050] In another aspect, the present invention provides a display device comprising: a first light-emitting device emitting light in a first hue; a second light-emitting device emitting light in a second hue; and a third light-emitting device emitting light in a third hue. Each of the first, second, and third light-emitting devices includes an intermediate layer and multiple light-emitting layers, with the intermediate layer located between the multiple light-emitting layers. Each of the multiple light-emitting layers in each of the first to third light-emitting devices contains a light-emitting central material and multiple host materials. In each of the first to third light-emitting devices, the light-emitting central material contained in the multiple light-emitting layers of a single light-emitting device is the same organic compound, and the light-emitting central material contained in the light-emitting layer of the third light-emitting device is a fluorescent light-emitting material.

[0051] In addition, one aspect of the present invention is a display device, comprising: a first light-emitting device; a second light-emitting device; and a third light-emitting device. The first light-emitting device sequentially comprises a first emitting layer 1a, an intermediate layer a, and a second emitting layer 2a; the second light-emitting device sequentially comprises a first emitting layer 1b, an intermediate layer b, and a second emitting layer 2b; and the third light-emitting device sequentially comprises a first emitting layer 1c, an intermediate layer c, and a second emitting layer 2c. The first and second emitting layers 1a and 2a contain a light-emitting central substance a, a first emitting organic compound, and a second emitting organic compound; the first and second emitting layers 1b and 2b contain a light-emitting central substance b, an 11b organic compound, and a 12b organic compound; and the first and second emitting layers 1c and 2c contain a light-emitting central substance c, a 15c organic compound, and a 16c organic compound. The light-emitting central substances a to c are light-emitting substances that exhibit different hues, and the light-emitting central substance a is a fluorescent light-emitting substance.

[0052] Another aspect of the present invention is an electronic device, comprising: the aforementioned light-emitting device; and a sensor, an operation button, a speaker, or a microphone.

[0053] Another aspect of the present invention is a lighting device including the above-described light-emitting device and frame.

[0054] The above is one aspect of the present invention and is not limited to the structure described above.

[0055] Invention Effects According to one aspect of the present invention, a light-emitting device with good characteristics can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with good luminous efficiency can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with good reliability can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with low driving voltage can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with both good reliability and low driving voltage can be provided.

[0056] Furthermore, according to one aspect of the present invention, a light-emitting device capable of providing a display device with good characteristics can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device capable of providing a display device with good luminous efficiency can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device capable of providing a display device with good reliability can be provided. Furthermore, according to one aspect of the present invention, a display device with low driving voltage can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device capable of providing both low driving voltage and good reliability in a display device can be provided.

[0057] Furthermore, according to one aspect of the present invention, any one of a low-power organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device can be provided. Furthermore, according to one aspect of the present invention, any one of a highly reliable electronic device and a lighting device can be provided. Attached Figure Description

[0058] Figures 1A to 1C This is a schematic diagram of a light-emitting device according to one aspect of the present invention.

[0059] Figure 2A and Figure 2B This is a schematic diagram of a light-emitting device according to one aspect of the present invention.

[0060] Figure 3A and Figure 3B This is a diagram illustrating a display device according to one aspect of the present invention.

[0061] Figure 4A and Figure 4B This is a diagram illustrating a display device according to one aspect of the present invention.

[0062] Figures 5A to 5E This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0063] Figure 6A and Figure 6B This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0064] Figures 7A to 7D This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0065] Figures 8A to 8C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0066] Figures 9A to 9C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0067] Figures 10A to 10C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0068] Figure 11A and Figure 11B This is a perspective view showing an example of the structure of a display module.

[0069] Figure 12A and Figure 12B This is a cross-sectional view showing an example of the structure of a light-emitting device.

[0070] Figure 13 This is a perspective view showing an example of the structure of a display device.

[0071] Figure 14 This is a cross-sectional view showing an example of the structure of a display device.

[0072] Figure 15 This is a cross-sectional view showing an example of the structure of a display device.

[0073] Figures 16A to 16C This is a perspective view showing an example of the structure of a display device.

[0074] Figure 17 This is a cross-sectional view showing an example of the structure of a display device.

[0075] Figures 18A to 18C This is a perspective view showing an example of the structure of a display device.

[0076] Figures 19A to 19D This is a diagram illustrating an example of a wearable device.

[0077] Figures 20A to 20F This is a diagram illustrating an example of an electronic device.

[0078] Figures 21A to 21G This is a diagram illustrating an example of an electronic device.

[0079] Figure 22 This is a graph showing the brightness-current density characteristics of light-emitting devices R1-1 and R1-2.

[0080] Figure 23 This is a graph showing the current efficiency-brightness characteristics of light-emitting devices R1-1 and R1-2.

[0081] Figure 24 This is a graph showing the current density-voltage characteristics of light-emitting devices R1-1 and R1-2.

[0082] Figure 25 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices R1-1 and R1-2.

[0083] Figure 26 This is a diagram showing the electroluminescence spectra of light-emitting devices R1-1 and R1-2.

[0084] Figure 27 This is a graph showing the luminance-current density characteristics of light-emitting devices G1-1 and G1-2.

[0085] Figure 28 This is a graph showing the current efficiency-brightness characteristics of light-emitting devices G1-1 and G1-2.

[0086] Figure 29 This is a graph showing the current density-voltage characteristics of light-emitting device G and comparative light-emitting device G1.

[0087] Figure 30 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices G1-1 and G1-2.

[0088] Figure 31 This is a diagram showing the electroluminescence spectra of light-emitting devices G1-1 and G1-2.

[0089] Figure 32 This is a graph showing the luminance-current density characteristics of light-emitting devices B1-1 to B1-4.

[0090] Figure 33 This is a graph showing the current efficiency-luminance characteristics of light-emitting devices B1-1 to B1-4.

[0091] Figure 34 This is a graph showing the current density-voltage characteristics of light-emitting devices B1-1 to B1-4.

[0092] Figure 35 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices B1-1 to B1-4.

[0093] Figure 36 This is a graph showing the blue index (BI) - brightness characteristics of light-emitting devices B1-1 to B1-4.

[0094] Figure 37 This is a diagram showing the electroluminescence spectra of light-emitting devices B1-1 to B1-4.

[0095] Figure 38 This is a graph showing the fluorescence and phosphorescence spectra of DBfBB1TP.

[0096] Figure 39 This is a graph showing the fluorescence and phosphorescence spectra of αN-βNPAnth.

[0097] Figure 40A and Figure 40B The graph shows the fluorescence and phosphorescence spectra of 3,10PCA2Nbf(IV)-02.

[0098] Figure 41 This is a graph showing the fluorescence and phosphorescence spectra of Bnf(II)PhA.

[0099] Figure 42 This is a diagram illustrating the method for calculating the T1 energy level.

[0100] Figure 43 This is a graph showing the brightness-current density characteristics of light-emitting devices R2-1 and R2-2.

[0101] Figure 44 This is a graph showing the current efficiency-brightness characteristics of light-emitting devices R2-1 and R2-2.

[0102] Figure 45 This is a graph showing the current density-voltage characteristics of light-emitting devices R2-1 and R2-2.

[0103] Figure 46 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices R2-1 and R2-2.

[0104] Figure 47 This is a graph showing the electroluminescence spectra of light-emitting devices R2-1 and R2-2.

[0105] Figure 48 This is a graph showing the luminance-current density characteristics of light-emitting devices G2-1 and G2-2.

[0106] Figure 49 This is a graph showing the current efficiency-brightness characteristics of light-emitting devices G2-1 and G2-2.

[0107] Figure 50 This is a graph showing the current density-voltage characteristics of light-emitting device G and comparative light-emitting device G2.

[0108] Figure 51 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices G2-1 and G2-2.

[0109] Figure 52 This is a diagram showing the electroluminescence spectra of light-emitting devices G2-1 and G2-2.

[0110] Figure 53 This is a graph showing the luminance-current density characteristics of light-emitting devices B2-1 to B2-4.

[0111] Figure 54 This is a graph showing the current efficiency-luminance characteristics of light-emitting devices B2-1 to B2-4.

[0112] Figure 55 This is a graph showing the current density-voltage characteristics of light-emitting devices B2-1 to B2-4.

[0113] Figure 56 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices B2-1 to B2-4.

[0114] Figure 57 This is a diagram showing the blue index-brightness characteristics of light-emitting devices B2-1 to B2-4.

[0115] Figure 58 This is a diagram showing the electroluminescence spectra of light-emitting devices B2-1 to B2-4.

[0116] Figure 59 This is a graph showing the luminance-current density characteristics of light-emitting devices R3, G3, and B3.

[0117] Figure 60 This is a graph showing the current efficiency-luminance characteristics of light-emitting devices R3, G3, and B3.

[0118] Figure 61 This is a graph showing the current density-voltage characteristics of light-emitting devices R3, G3, and B3.

[0119] Figure 62 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices R3, G3, and B3.

[0120] Figure 63 This is a graph showing the blue light efficiency index-current density characteristics of the light-emitting device B3.

[0121] Figure 64 This is a graph showing the electroluminescence spectra of light-emitting devices R3, G3, and B3.

[0122] Figure 65A This is a graph showing the fluorescence spectrum of Bnf(II)PhA-02-d5. Figure 65B This is a graph showing the phosphorescence spectrum of Bnf(II)PhA-02-d5.

[0123] Figure 66 This is a graph showing the luminance-current density characteristics of light-emitting devices R4-1 and R4-2.

[0124] Figure 67 This is a graph showing the current efficiency-brightness characteristics of light-emitting devices R4-1 and R4-2.

[0125] Figure 68 This is a graph showing the current density-voltage characteristics of light-emitting devices R4-1 and R4-2.

[0126] Figure 69 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices R4-1 and R4-2.

[0127] Figure 70 This is a diagram showing the electroluminescence spectra of light-emitting devices R4-1 and R4-2.

[0128] Figure 71This is a graph showing the luminance-current density characteristics of light-emitting devices G4-1 and G4-2.

[0129] Figure 72 This is a graph showing the current efficiency-luminance characteristics of light-emitting devices G4-1 and G4-2.

[0130] Figure 73 This is a graph showing the current density-voltage characteristics of light-emitting device G4-1 and comparative light-emitting device G4-2.

[0131] Figure 74 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices G4-1 and G4-2.

[0132] Figure 75 This is a diagram showing the electroluminescence spectra of light-emitting devices G4-1 and G4-2.

[0133] Figure 76 This is a graph showing the luminance-current density characteristics of light-emitting devices B4-1 to B4-3.

[0134] Figure 77 This is a graph showing the current efficiency-luminance characteristics of light-emitting devices B4-1 to B4-3.

[0135] Figure 78 This is a graph showing the current density-voltage characteristics of light-emitting devices B4-1 to B4-3.

[0136] Figure 79 This is a graph showing the power efficiency-luminance characteristics of light-emitting devices B4-1 to B4-3.

[0137] Figure 80 This is a graph showing the blue index (BI) - brightness characteristics of light-emitting devices B4-1 to B4-3.

[0138] Figure 81 This is a diagram showing the electroluminescence spectra of light-emitting devices B4-1 to B4-3. Detailed Implementation

[0139] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the following description, and those skilled in the art will readily understand that its methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited only to the contents described in the embodiments shown below.

[0140] Note that in this specification, etc., devices manufactured using metal masks or FMMs (Fine Metal Masks) are sometimes referred to as devices with MM (Metal Mask) structures. Furthermore, in this specification, etc., devices manufactured without metal masks or FMMs are sometimes referred to as devices with MML (Metal Mask Less) structures.

[0141] Furthermore, in this specification, "containing deuterium" refers to an organic compound in which the proportion of deuterium among hydrogen and deuterium significantly exceeds the naturally occurring proportion of deuterium, specifically, a proportion more than 500 times that naturally occurring proportion. "Deuterated organic compound" refers to an organic compound in which the proportion of deuterium among hydrogen and deuterium significantly exceeds the naturally occurring proportion of deuterium, specifically, an organic compound in which the proportion of deuterium among hydrogen and deuterium is more than 500 times that naturally occurring proportion. Additionally, the aforementioned proportions are not based on a single molecule, but rather on the average proportion of multiple organic compounds present in a certain region.

[0142] (Implementation Method 1) A series-connected light-emitting device has a structure in which multiple light-emitting units are stacked with an intermediate layer (charge-generating layer) sandwiched between a pair of electrodes. Each light-emitting unit includes a light-emitting layer, and light can be emitted from each light-emitting layer by flowing current through it. The current efficiency of a series-connected light-emitting device with this structure is much higher than that of a non-series-connected light-emitting device, so it is suitable for display devices that require high brightness or high reliability.

[0143] Series-type light-emitting devices (LEDs) easily produce white light due to their multiple light-emitting layers; therefore, white filters are commonly used to achieve full-color display devices employing series-type LEDs. Furthermore, color conversion methods that use stacked blue light-emitting layers and color conversion layers, such as quantum dots, have also been practically applied.

[0144] On the other hand, some display devices that use a separate coating method and series-type light-emitting devices as a full-color method have also been put into practical use. In light-emitting devices using the separate coating method, there is little or no energy loss in the color filter or color conversion layer, so higher luminous efficiency can be obtained compared with the two methods mentioned above.

[0145] In one embodiment of the present invention, a tandem light-emitting device includes at least one light-emitting layer comprising a fluorescent light-emitting material, a first host material, and a second host material. Preferably, both the first host material and the second host material are organic compounds and both contain polycyclic aromatic hydrocarbons (PAHs). That is, the first host material is a first organic compound containing a first PAH, and the second host material is a second organic compound containing a second PAH.

[0146] The first polycyclic hydrocarbon contained in the first organic compound is preferably an aromatic hydrocarbon with 6 to 22 carbon atoms, thereby allowing for efficient injection of charge carriers into the luminescent layer. Furthermore, it provides a luminescent element with high luminous efficiency and long drive lifetime, making it preferred. Note that the first polycyclic hydrocarbon preferably has an anthracene skeleton, thereby enabling efficient luminescence of the fluorescent material. Additionally, when the first polycyclic hydrocarbon has an anthracene skeleton, the anthracene skeleton preferably has substituents at positions 9 and 10, thereby providing a highly reliable luminescent element. Furthermore, the first organic compound preferably also contains a first aromatic ring. The first aromatic ring can be an aromatic hydrocarbon or a polycyclic heteroaromatic ring.

[0147] Furthermore, in this structure, the second polycyclic hydrocarbon contained in the second organic compound is preferably an aromatic hydrocarbon with 6 to 30 carbon atoms, thereby allowing for efficient injection of charge carriers into the luminescent layer. Additionally, it provides a luminescent element with high luminous efficiency and long drive lifetime, making it preferred. The second polycyclic hydrocarbon preferably has an anthracene skeleton, thereby enabling efficient luminescence of the fluorescent material. When the second polycyclic hydrocarbon has an anthracene skeleton, the anthracene skeleton preferably has substituents at positions 9 and 10. Furthermore, the second organic compound preferably also has a second aromatic ring. The second aromatic ring can be an aromatic hydrocarbon or a polycyclic heteroaromatic ring.

[0148] Furthermore, when the first polycyclic hydrocarbon in the first organic compound is the same as the second polycyclic hydrocarbon in the second organic compound, the carrier balance of the light-emitting layer is improved, resulting in a light-emitting element with high luminous efficiency, which is preferred. However, the first organic compound and the second organic compound are different organic compounds. By adopting this structure, the carrier balance of the light-emitting layer is improved, and the heat resistance of the light-emitting layer is enhanced, thereby improving the overall heat resistance of the light-emitting element. Furthermore, when the first organic compound and the second organic compound are different organic compounds, and they are organic compounds with different carrier transport properties, a good carrier balance can be achieved, which is also preferred. Additionally, the weight ratio or volume ratio of the first organic compound to the second organic compound is preferably 1:19 to 19:1, more preferably 1:9 to 9:1, and even more preferably 3:7 to 7:3.

[0149] Furthermore, the first aromatic ring contained in the first organic compound and the second aromatic ring contained in the second organic compound can be the same aromatic ring (monocyclic or polycyclic) or different aromatic rings. When they contain the same aromatic ring, the same raw materials can sometimes be used to manufacture the two host materials, which can lead to a reduction in raw material costs or a shortening of the synthetic steps. Note that the first organic compound and the second organic compound are different organic compounds.

[0150] Examples of fused rings (also called fused structures) that serve as the first and second aromatic rings include naphthene, fluorene, benzofluorene, triphenylene, benzonaphthofuran, xanthene, benzooxanthene, spirofluorenexanthene (also known as SFx), spirobenzofluorenexanthene (also known as Sbfx), carbazole, benzocarbazole, dibenzofuran, dibenzothiophene, and benzonaphthothiophene. Their structures are shown below. Note that in the cases where the aromatic rings shown below have substituents, any one carbon or nitrogen atom is bonded.

[0151] [Chemical Formula 1] Furthermore, these fused rings can adjust the carrier transport or Tg depending on the bonding positions (also called bonding sites) with other groups, and therefore can be used in various layers. For example, it is preferable to use a naphthalene ring with a bonding site at the 1-position as an electron transport layer material and a naphthalene ring with a bonding site at the 2-position as a hole transport layer material. It is also preferable to use a naphthalene ring with a bonding site at the 2-position as the host material of the luminescent layer and a naphthalene ring with a bonding site at the 1-position as the hole transport layer material. Furthermore, when using a naphthalene ring as a linker, it is preferable to use a naphthalene ring with bonding sites at both the 1- and 2-positions as an electron transport layer material and a naphthalene ring with bonding sites at both the 1- and 6-positions as the host material of the luminescent layer. Thus, it is preferable to use fused rings with different bonding sites for the compounds used in one layer and those used in another layer.

[0152] Furthermore, when multiple layers use the same fused ring, it is preferable to use different substituents, such as using a fused ring bonded with a cyano group (naphthalene ring, etc.) as an electron transport layer material, and using a fused ring bonded with an alkyl group (naphthalene ring, etc.) as a hole transport layer material. Materials corresponding to the properties required for each layer can be provided.

[0153] Furthermore, aromatic rings with structural isomers can be used, not just the same aromatic ring. By using aromatic rings with structural isomers, the same starting materials can sometimes be used as described above, thus reducing raw material costs or shortening the synthetic steps. For example, as structural isomers of the benzo[b]naphtho[2,1-d]furan ring (also known as the aBnf skeleton), the benzo[b]naphtho[2,3-d]furan ring (also known as the Bnf(II) skeleton), and the benzo[b]naphtho[1,2-d]furan ring (also known as the Bnf skeleton) are three examples of fused structures, depending on the position of the fused ring in the benzene ring. The specific structures of these skeletons are shown below. In the benzo[b]naphtho[furan] ring shown below, where substituents are present, any carbon or nitrogen atom is bonded.

[0154] [Chemical Formula 2] The above-mentioned aBnf framework can be used as the material for the electron transport layer, the above-mentioned Bnf(II) framework can be used as the main material for the light-emitting layer, and the above-mentioned Bnf can be used as the material for the hole transport layer.

[0155] Thus, since the properties (carrier transport, HOMO, LUMO, etc.) of materials using aromatic rings with structural isomorphism are different, appropriate aromatic rings can be used according to the properties required for each layer. In addition to adjusting Tg, reducing raw material costs, and shortening the synthesis steps mentioned above, the properties can also be improved.

[0156] Furthermore, the host materials in each light-emitting layer of the red, green, and blue light-emitting devices preferably contain aromatic rings with structural isomerism. Additionally, when different materials are used for the hole transport layers of different colors, aromatic rings with structural isomerism may also be included. Furthermore, in the case of multiple electron transport layers, these multiple layers preferably also contain aromatic rings with structural isomerism. The same applies when multiple hole transport layers are included. Thus, the multiple materials used in the organic device preferably contain aromatic rings with structural isomerism. Furthermore, in the case of a fused ring structure, aromatic rings with structural isomerism can also be referred to as aromatic rings with equal molecular weights but different fusion positions. This is not limited to benzo[a]naphtho[furan] rings; the same applies to other aromatic rings mentioned above (benzo[a]fluorene ring, benzo[a]oxane ring, spirobenzo[a]fluoreneoxane ring, benzo[a]carbazole ring, benzo[a]naphtho[thiophene ring, etc.). As mentioned above, "benzonaphthofuran ring" is a term that includes structural isomers such as aBnf, Bnf(II), and Bnf, and other fused rings are also terms that include structural isomers.

[0157] Note that each fused ring in the structural formula can also have substituents. Different compounds can have the same substituents or different substituents.

[0158] When both the first and second organic compounds are aromatic hydrocarbons, a light-emitting element with high luminous efficiency and long driving life can be obtained, which is preferred. Furthermore, when one of the first and second organic compounds is an aromatic hydrocarbon and the other is an organic compound with a polycyclic heteroaromatic ring, changes in luminous efficiency accompanying brightness variations can be suppressed, and a light-emitting device capable of providing a display device with good display quality can be realized, which is also preferred.

[0159] As described above, the first polycyclic hydrocarbon in the first organic compound and the second polycyclic hydrocarbon in the second organic compound preferably contain an anthracene skeleton. That is, in a light-emitting device according to one aspect of the present invention, the first organic compound and the second organic compound are preferably each independently an organic compound represented by the following general formula (GO). However, the first organic compound and the second organic compound are different organic compounds.

[0160] [Chemical Formula 3] In the general formula (G0), R 101 To R 110 Each of the following can be independently represented: hydrogen (including deuterium), a branched or straight-chain alkyl group with 1 to 8 substituted or unsubstituted carbon atoms, a cycloalkyl group with 3 to 10 substituted or unsubstituted carbon atoms, an aryl group with 6 to 22 substituted or unsubstituted carbon atoms, or a heteroaryl group with 1 to 30 substituted or unsubstituted carbon atoms, preferably hydrogen (including deuterium), phenyl, naphthyl, phenylnaphthyl, dibenzofuranyl, naphthobenzofuranyl, etc. Note that the organic compound represented by the above general formula (G0) is preferably in the R... 109 and R 110 It has substituents.

[0161] Furthermore, when both the first and second organic compounds are aromatic hydrocarbons, it is easy to obtain a light-emitting element with high luminous efficiency and long driving life, which is therefore preferred. That is, in a light-emitting device according to one aspect of the present invention, the first and second organic compounds are preferably organic compounds represented independently by the following general formula (G1). However, the first and second organic compounds may be different organic compounds.

[0162] [Chemical Formula 4] In the general formula (G1), R 1 To R 10Each of the following can be independently represented: hydrogen (including deuterium), a branched or straight-chain alkyl group having 1 to 8 carbon atoms (substituted or unsubstituted), a cycloalkyl group having 3 to 10 carbon atoms (substituted or unsubstituted), or an aryl group having 6 to 22 carbon atoms (substituted or unsubstituted), preferably hydrogen (including deuterium), phenyl, naphthyl, phenylnaphthyl, etc. Furthermore, organic compounds represented by the above general formula (G1) are preferably in R... 9 and R 10 The position includes substituents.

[0163] Furthermore, when the first organic compound is an aromatic hydrocarbon and the second organic compound is an organic compound having a polycyclic heterocyclic aromatic ring, the change in luminous efficiency accompanying the change in brightness can be suppressed, and a light-emitting device that can provide a display device with good display quality can be realized, which is therefore preferred. That is, it is preferred that the first organic compound is an organic compound represented by the following general formula (G1) and the second organic compound is an organic compound represented by the following general formula (G2).

[0164] [Chemical Formula 5] In the general formula (G1), R 1 To R 10 Each of the following can be independently represented: hydrogen (including deuterium), a branched or straight-chain alkyl group having 1 to 8 carbon atoms (substituted or unsubstituted), a cycloalkyl group having 3 to 10 carbon atoms (substituted or unsubstituted), or an aryl group having 6 to 22 carbon atoms (substituted or unsubstituted), preferably hydrogen (including deuterium), phenyl, naphthyl, phenylnaphthyl, etc. Furthermore, organic compounds represented by the above general formula (G1) are preferably in R... 9 and R 10 The position includes substituents.

[0165] [Chemical Formula 6] In the general formula (G2), R 11 To R 20 Each of the following independently represents hydrogen (including deuterium), a branched or straight-chain alkyl group with 1 to 8 substituted or unsubstituted carbon atoms, a cycloalkyl group with 3 to 10 substituted or unsubstituted carbon atoms, an aryl group with 6 to 22 substituted or unsubstituted carbon atoms, or a heteroaryl group with 1 to 30 substituted or unsubstituted carbon atoms, R 11 To R 20 At least one of the aryl groups in the formula represents a heteroaryl group having substituted or unsubstituted carbon atoms from 1 to 30. Note that phenyl, naphthyl, or phenylnaphthyl are preferred as aryl groups having 6 to 22 carbon atoms, and dibenzofuranyl, naphthobenzofuranyl, etc., are preferred as heteroaryl groups having 1 to 30 carbon atoms. Furthermore, the organic compound represented by the above general formula (G2) is preferably in the R... 19 and R20 The position includes substituents.

[0166] Furthermore, in the above general formulas (G0) to (G2), the cycloalkyl group having 3 to 10 carbon atoms, whether substituted or unsubstituted, can be exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, cycloheptyl, 1-adamantyl, and 2-adamantyl. Additionally, when the cycloalkyl group having 3 to 10 carbon atoms has a substituent, examples of such substituents include alkyl groups having 1 to 4 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, or aryl groups having 6 to 13 carbon atoms.

[0167] Furthermore, in the above general formulas (G0) to (G2), examples of aryl groups having 6 to 22 substituted or unsubstituted carbon atoms include phenyl, o-tolyl, m-tolyl, p-tolyl, mesitylelel, biphenyl-2-yl (o-biphenyl), biphenyl-3-yl (m-biphenyl), biphenyl-4-yl (p-biphenyl), 1-naphthyl, 2-naphthyl, phenylnaphthyl, naphthylphenyl, terphenyl, fluorenyl, 9,9-dimethylfluorenyl, phenanthryl, anthracenel, binatylphenyl, fluoranyl, etc. Note that when the aryl group having 6 to 22 carbon atoms has a substituent, examples of such substituents include alkyl groups having 1 to 4 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, or aryl groups having 6 to 13 carbon atoms.

[0168] Furthermore, in the above general formulas (G0) to (G2), heteroaryl groups having 1 to 30 carbon atoms as substituted or unsubstituted groups can be exemplified by, for example, pyridinyl, pyrimidinyl, triazinyl, phenanthroline-yl, carbazole-yl, pyrrolo-yl, thiophene-yl, furanyl, imidazolyl, bipyridinyl, bipyrimidinyl, pyrazinyl, bipyrazinyl, quinolinyl, isoquinolinyl, benzoquinolinyl, quinoxalinyl, benzoquinoxalinyl, dibenzoquinoxalinyl, azafluorene-yl, diazafluorene-yl, benzocarbazole-yl, dibenzocarbazole-yl, dibenzofuran-yl, benzofuran-yl, and benzene-yl. Naphthofuran-yl, dinaphthofuran-yl, dibenzothiophen-yl, benzothiophen-yl, benzonaphthothiophen-yl, dinaphthothiophen-yl, benzofuran-pyridin-yl, benzofuran-pyrimidin-yl, benzothiophene-pyridin-yl, benzothiophene-pyrimidin-yl, naphthofuran-pyridin-yl, naphthothiophene-pyridin-yl, naphthothiophene-pyrimidin-yl, dibenzoquinoxalin-yl, acridine-yl, oxanthracene-yl, phenothiazin-yl, phenothiazin-yl, phenothiazin-yl, triazol-yl, oxazol-yl, oxadiazol-yl, thiazole-yl, thiaazole-yl, thiadiazole-yl, benzimidazole-yl, or pyrazol-yl, etc. Furthermore, when a heteroaryl group having 1 to 30 carbon atoms has a substituent, examples of such substituents include alkyl groups having 1 to 4 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, or aryl groups having 6 to 13 carbon atoms.

[0169] Furthermore, it is preferable that one or both of the first and second organic compounds are deuterated, thereby providing a light-emitting element with a long driving life. All hydrogens contained in the organic compound may be deuterated, or only some of the hydrogens may be deuterated. In the case where only some hydrogens are deuterated, it is preferable to deuterate the first polycyclic hydrocarbon, the second polycyclic hydrocarbon, and the first polycyclic heteroaromatic ring, thereby improving the effect of extending the driving life.

[0170] Furthermore, it is preferable that the organic compound represented by (G2) above has a carbazole skeleton, thereby improving hole injection / transportation. More preferably, the organic compound represented by (G2) above includes a benzo[a]carbazole skeleton with a benzene ring fused to a carbazole, whose HOMO level is about 0.1 eV higher than that of an organic compound having only a carbazole skeleton, making hole injection easier. In particular, when the host material has a dibenzo[a]carbazole skeleton, its HOMO level is about 0.1 eV higher than that of a host material with a carbazole skeleton, which not only facilitates hole injection but also improves hole transport and heat resistance, making it preferred. Therefore, it is further preferred as a host material to have both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzo[a]carbazole skeleton or a dibenzo[a]carbazole skeleton). Note that from the viewpoint of hole injection / transportation, a benzo[a]fluorene skeleton or a dibenzo[a]fluorene skeleton can also be used instead of a carbazole skeleton.

[0171] Preferred specific examples of organic compounds represented by the above general formula (G1) include 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl]anthracene (abbreviated as FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviated as α,β-ADN), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviated as βN-mβNPAnth), 1-{4-[10-(2-naphthyl)-9-anthrayl]phenyl}-2-ethyl-1H-benzimidazole (abbreviated as βN-EtBImPAnth), etc.

[0172] Furthermore, as preferred specific examples of organic compounds represented by the above general formula (G2), examples include 9-[4-(9-phenylcarbazo-3-yl)]phenyl-10-phenylanthracene (abbreviated as PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazo(abbreviated as PCPN), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazo(abbreviated as CzPA), 7-[4-(10- [Phenyl-9-anthrayl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthrayl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 2-(10-phenyl-9-anthrayl)benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 1-{4-[10-(biphenyl-4- 1-(10-phenyl-9-anthrayl)-9-benzo[b]naphtho[2,1-d]furan (abbreviation: EtBImPBPhA), 2-(10-phenyl-9-anthrayl)dibenzofuran (abbreviation: DBfPhA), 7-(10-phenyl-9-anthrayl)benzo[b]naphtho[2,1-d]furan (abbreviation: aBnfPhA), 1-[10-(phenyl-2,3,4,5,6-d5)-9-anthrayl]benzo[b]naphtho[2,1-d]furan 3-d]furan (abbreviation: Bnf(II)PhA-02-d5), 7-(phenyl-2,3,4,5,6-d5)-1-[10-(phenyl-2,3,4,5,6-d5)-9-anthrayl]dibenzofuran (abbreviation: PDBfPhA-d10), 2-[10-(biphenyl-2-yl)-9-anthrayl]benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)oBPhA), etc.

[0173] In addition, if the first organic compound and / or the second organic compound are deuterated organic compounds, organic compounds that have been appropriately deuterated from the aforementioned organic compounds can be used.

[0174] Examples of organic compounds represented by the above general formula (G1) include organic compounds represented by the following structural formulas (100) to (117).

[0175] [Chemical Formula 7] [Chemical Formula 8] Examples of organic compounds represented by the above general formula (G2) include organic compounds represented by the following structural formulas (200) to (215).

[0176] [Chemical Formula 9] [Chemical Formula 10] Note that the organic compound represented by the above general formula (G0) corresponds to both specific examples of the organic compound represented by the above general formula (G1) and specific examples of the organic compound represented by the above general formula (G2).

[0177] In one embodiment of the light-emitting device of the present invention, it is preferable that the lowest singlet excitation energy level (S1 level) of the fluorescent luminescent material used in the luminescent layer is lower than the S1 energy level of the first host material and the second host material, and the lowest triplet excitation energy level (T1 level) of the fluorescent luminescent material is higher than the T1 energy level of the first host material and / or the T1 energy level of the second host material. This allows for efficient upconversion to singlet excitons using triplet-triplet-Annihilation (TTA).

[0178] The upconversion to singlet excitons via TTA is achieved through the following reaction: via TTA, triplet excitons generated by carrier recombination interact, transferring excitation energy and exchanging spin angular momentum, ultimately converting into singlet excitons with the energy of the S1 level of the host material. The energy of the generated singlet excitons is higher than the energy of the S1 level of the fluorescent material, thus converting the triplet excitation energy of the host material into fluorescence. Therefore, the light-emitting device according to one aspect of this invention can achieve more efficient light emission.

[0179] In other words, in the light-emitting device of the present invention, which includes a fluorescent luminescent material, a first organic compound, and a second organic compound, it is preferable that the S1 energy level of the first organic compound and the S1 energy level of the second organic compound are higher than the S1 energy level of the fluorescent luminescent material, and the T1 energy level of the first organic compound or the T1 energy level of the second organic compound is lower than the T1 energy level of the fluorescent luminescent material. More preferably, the T1 energy levels of both the first organic compound and the second organic compound are lower than the T1 energy level of the fluorescent luminescent material.

[0180] For calculating the S1 energy level of organic compounds, a tangent line is drawn at the point where the slope of the peak on the short wavelength side of the fluorescence spectrum is the largest. The wavelength energy of the intersection of this tangent line with the horizontal axis (wavelength) or the baseline is set as the S1 energy level. Similarly, for calculating the T1 energy level of organic compounds, a tangent line is drawn at the point where the slope of the peak on the short wavelength side of the phosphorescence spectrum is the largest. The energy of the intersection of this tangent line with the horizontal axis (wavelength) or the baseline is set as the T1 energy level (e.g., see Daisaku TANAKA et al., “UltraHigh Efficiency Green Organic Light-Emitting Devices”, Japanese Journal of Applied Physics, Vol.46, No.1, 2007, pp. L10-L12). Furthermore, as another method, when a ν=0→ν=0 transition (0→0 band) between the vibrational energy levels of the ground and excited states is clearly observed in the fluorescence or phosphorescence spectra, the D1 energy level can also be calculated using this 0→0 band. Energy levels, S1 level, or T1 level (Nicholas J. Turro, V. Ramamurthy, and JC Scaiano, edited and translated by Haruo Inoue and Osamu Itō, "Principles of Molecular Photochemistry," Maruzen Publishing Co., Ltd., July 30, 2013, pp. 165-169; Nicholas J. Turro, V. Ramamurthy, and JC Scaiano, "Modern Molecular Photochemistry of Organic Molecules," University Science Books, February 10, 2010, pp. 204-208). In this specification, each energy level is calculated using the former method of tangent lines. Furthermore, when comparing energy levels, comparisons are made with energy levels calculated using the same method.

[0181] Here, the measurements of each spectrum can be performed in either the thin film state or the solution state, but from the viewpoint of verifying the state of isolated molecules, the fluorescent luminescent material is preferably in solution. However, when comparing spectra, data obtained with the same sample shape should be compared as much as possible, such as comparing the measurement results of thin films with thin films or comparing the measurement results of solutions with solutions.

[0182] When the measurement is performed in solution, hexane, benzene, toluene, diethyl ether, ethyl acetate, chloroform, chlorobenzene, dichloromethane, 2-methyltetrahydrofuran (2-MeTHF) and other solvents can be used, with toluene, dichloromethane and 2-MeTHF being preferred.

[0183] Alternatively, a mixed solvent of iodobenzene:dichloromethane:toluene = 20%:40%:40% can be used, which can form a good glassy state when observing phosphorescent components at low temperatures.

[0184] When observing phosphorescence spectra in solution, measurements are preferably performed at a temperature of 77 K, which is the temperature of liquid nitrogen. Furthermore, when observing phosphorescence spectra with thin films, since the temperature of liquid helium is 4 K, measurements are preferably performed at a temperature between approximately 4 K and 10 K. Additionally, when measuring emission spectra at low temperatures, delayed fluorescence spectra sometimes appear in addition to phosphorescence spectra. In this case, comparing the emission spectrum (fluorescence spectrum) with that at room temperature allows identification of the emission spectrum with a peak at the same wavelength as the fluorescence emission spectrum as the delayed fluorescence spectrum.

[0185] Furthermore, in one embodiment of the light-emitting device of the present invention, it is preferable that one or both of the first host material and the second host material are deuterated. That is, it is preferable that one or both of the first organic compound and the second organic compound are deuterated. Deuteration can mean that all the hydrogen contained in the organic compound is deuterated, or it can mean that only a portion of the hydrogen is deuterated. By deuterating one or both of the first host material and the second host material, a light-emitting element with a long driving life can be provided, and therefore it is preferred.

[0186] A light-emitting device of one embodiment of the present invention having the structure described above can be a high-efficiency, high-reliability light-emitting device with excellent lifespan. Furthermore, it can also reduce the driving voltage.

[0187] Note that in this tandem light-emitting device, the intermediate layer preferably comprises a fifth organic compound having a phenanthroline skeleton. Additionally, the electron transport layer of the light-emitting unit on the cathode side preferably comprises a sixth organic compound having a triazine skeleton. Furthermore, the electron transport layer of the light-emitting unit on the cathode side preferably comprises a first organic compound having a triazine skeleton. Additionally, the intermediate layer preferably comprises a fifth organic compound having a phenanthroline skeleton.

[0188] In one embodiment of the present invention, a tandem light-emitting device may include at least one light-emitting layer having the aforementioned structure, but preferably two or more light-emitting layers or all light-emitting layers have this structure. For example, in the case of a tandem light-emitting device comprising two light-emitting layers, a first light-emitting layer and a second light-emitting layer, it is preferable to employ a structure in which the first light-emitting layer comprises a first fluorescent luminescent material, a first organic compound, and a second organic compound, and the second light-emitting layer comprises a first fluorescent luminescent material, a third organic compound, and a fourth organic compound. Furthermore, the first organic compound and the third organic compound correspond to the first host material in each light-emitting layer, while the second organic compound and the fourth organic compound correspond to the second host material in each light-emitting layer.

[0189] Furthermore, the light-emitting layer of the tandem light-emitting device is preferably separate from the light-emitting layer of at least one of the adjacent light-emitting devices. Alternatively, the light-emitting layer of the tandem light-emitting device preferably includes a light-emitting layer different from the light-emitting layer of at least one of the adjacent light-emitting devices. Alternatively, the color of the light emitted by the tandem light-emitting device or pixel is preferably different from the color of the light emitted by at least one of the adjacent light-emitting devices or pixels. Alternatively, the light-emitting core material included in the light-emitting layer of the tandem light-emitting device is preferably different from the light-emitting core material included in the light-emitting layer of at least one of the adjacent light-emitting devices.

[0190] Furthermore, in one embodiment of this tandem light-emitting device according to the present invention, it is preferable that the electron transport layer of the light-emitting unit on the cathode side comprises a sixth organic compound having a triazine framework. Additionally, the intermediate layer preferably comprises a fifth organic compound having a phenanthroline framework. When the electron transport layer of the light-emitting unit on the cathode side comprises a sixth organic compound, or when the intermediate layer also comprises a fifth organic compound, a tandem light-emitting device with a low driving voltage can be obtained. Furthermore, when the electron transport layer of the light-emitting unit on the cathode side comprises a sixth organic compound and the intermediate layer comprises a fifth organic compound, a tandem light-emitting device with an even lower driving voltage can be obtained.

[0191] Furthermore, when the electron transport layer of the light-emitting unit on the cathode side contains a sixth organic compound or / and the intermediate layer contains a fifth organic compound, and any light-emitting layer contains a fluorescent light-emitting material and a first host material and a second host material, a series-type light-emitting device with a lower driving voltage can be obtained, and the luminous efficiency is also improved. Therefore, a light-emitting device with high power efficiency and high energy efficiency can be realized.

[0192] Furthermore, by separating the light-emitting layer of the series-connected light-emitting device from the light-emitting layer of at least one of the adjacent light-emitting devices, or by including a light-emitting layer in the series-connected light-emitting device that is different from the light-emitting layer in at least one of the adjacent light-emitting devices, or by including a light-emitting color in the series-connected light-emitting device that is different from the light-emitting color in at least one of the adjacent light-emitting devices, or by including a light-emitting core material in the light-emitting layer of the series-connected light-emitting device that is different from the light-emitting core material in the light-emitting layer of at least one of the adjacent light-emitting devices, a light-emitting device with very good current efficiency can be obtained, thereby obtaining a light-emitting device with better power efficiency and energy efficiency.

[0193] As a result, a display device using this light-emitting device according to one aspect of the present invention can be a display device with low power consumption, high reliability, and good visibility capable of displaying at high brightness. Furthermore, it can also be a display device with good display quality.

[0194] The electron mobility of the aforementioned sixth organic compound with a triazine skeleton is preferably 1 × 10⁻⁶ when the square root of the electric field strength [V / cm] is 600. -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs and above.

[0195] The sixth organic compound having a triazine skeleton is preferably a compound having both a triazine skeleton and an aromatic ring. As the aromatic ring, monocyclic aromatic rings, polycyclic aromatic rings, aromatic rings with alkyl substituents, aromatic rings with fluorine substituents, and aromatic rings with cyano substituents are preferred. The triazine skeleton may also have substituents other than those mentioned above, and the aromatic ring may also have substituents other than those mentioned above. Note that the triazine skeleton is also referred to as a triazine ring; regarding other skeletons, the skeleton can be referred to as a ring.

[0196] Examples of monocyclic aromatic rings include benzene rings and other aromatic rings, as well as heterocyclic aromatic rings such as pyrrole rings, pyridine rings, pyrimidine rings, and triazine rings. The presence of an aromatic ring as a substituent improves heat resistance; specifically, it increases the glass transition temperature (Tg) and also enhances electron transport properties.

[0197] Examples of polycyclic aromatic rings include naphthalene rings, phenanthrene rings, cyclopentadiene rings, triphenylene rings, fluorene rings, spirodifluorene rings, carbazole rings, dibenzofuran rings, dibenzothiophene rings, xanthracene rings, indolecarbazole rings, indenecarbazole rings, and other heteroaromatic rings. Compounds with polycyclic aromatic rings as substituents are preferred because they improve heat resistance compared to compounds with monocyclic aromatic rings such as benzene rings. Furthermore, the heat resistance can be further improved when the substituent has a ring fused with the aforementioned polycyclic aromatic rings and aromatic rings (benzene rings, naphthalene rings, pyridine rings, etc.). Examples of rings fused with polycyclic aromatic rings and aromatic rings include benzo[a]fluorene rings, benzo[a]naphthofuran rings, benzo[a]oxanthracene rings, and benzo[a]naphthothiophene rings. By providing a layer containing a compound with high heat resistance near the cathode, thermal damage to the element during high-temperature processing such as patterning steps after the formation of this layer or the cathode can be suppressed.

[0198] Furthermore, examples of alkyl groups include methyl, ethyl, propyl, tert-butyl, cyclohexyl, and adamantyl. Using a layer with a compound having an alkyl group as a substituent can reduce the refractive index. Therefore, total internal reflection at the interface between this layer and other layers can be reduced, thereby improving light extraction efficiency. Furthermore, by also using the aforementioned substituent-containing compounds in the hole transport layer, the refractive index of the hole transport layer can be reduced. In particular, by using a compound having a triazine skeleton and an alkyl group in the electron transport layer and a compound having an aromatic amine skeleton and an alkyl group in the hole transport layer, the effect of improving light extraction efficiency can be multiplicatively enhanced. Additionally, when the number of carbon atoms in the alkyl group in the organic compound is multiple, preferably three or more, more preferably four or more, and even more preferably five or more, the effect of reducing the refractive index can be improved. Furthermore, using a layer with a compound having a fluorine group as a substituent can also reduce the refractive index, and is therefore preferred. In particular, when multiple fluorine groups are present, the effect of increasing the refractive index can be improved. Using compounds with fluorine groups in both the electron transport layer and the hole transport layer is also effective. Furthermore, compounds having a structure with an aromatic ring bonded to multiple alkyl groups can further reduce the refractive index of the layer. For example, structures in which a benzene ring is bonded to two or more tert-butyl groups as substituents can be cited. Besides the benzene ring, other monocyclic aromatic rings such as the pyridine ring, and polycyclic aromatic rings such as the fluorene ring, can also be bonded to multiple alkyl groups. Furthermore, structures in which a portion of the polycyclic aromatic ring (naphthalene ring, fluorene ring, carbazole ring, quinoline ring, xanthracene ring, etc.) is bonded to multiple alkyl groups are preferred. For example, structures in which a benzene ring constituting the fluorene ring is bonded to multiple tert-butyl groups can be cited.

[0199] In addition, compounds with cyano groups as substituents can improve electron transport properties, so they are preferred.

[0200] Furthermore, combinations of polycyclic aromatic rings, alkyl groups, fluorinated groups, and cyano groups are preferred as substituents. For example, when polycyclic aromatic rings and cyano groups are used as substituents, both heat resistance and electron transport properties can be improved. Furthermore, when polycyclic aromatic rings and alkyl groups are used, both heat resistance and photoextraction efficiency can be improved. Thus, substituents can be used in combinations according to the desired functions.

[0201] Furthermore, when the substituent has multiple polycyclic aromatic rings, the heat resistance can be further improved. In this case, it is preferable to have the above-mentioned aromatic rings and the above-mentioned heteroaromatic rings.

[0202] Specific examples of sixth organic compounds with a triazine skeleton include 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobis[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)... 9-[3-(4,6-diphenyl-1,3,5-triazine)]-9'-phenyl-2,3'-bi-9H-carbazole (mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indo[2,1-b]carbazole (mINc(II)PTzn), 2- {3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn) ), 2-[3'-(triphenyl-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-triphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]oxanthracene]-4-yl-1,3,5-Triazine (abbreviation: βNP-SFx(4)Tzn), 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-Pheny-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)Tz) n), 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazin-4,3''-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTzn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTzn), 9-[4,6- [Diphenyl-1,3,5-triazin-2-yl]-2-dibenzothiophene]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), 2,4-diphenyl-6-[3'-(spiro[7H-benzo[c]fluorene-7,9'-[9H]oxanthracene]-2'-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: mSbfxBPTzn), 3′-[4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]oxanthracene]-2′-yl)-1,3,5-triazin-2-yl]biphenyl-4-carboxylonitrile (abbreviation: mpCNBP-SFxTzn), 2,2'-[1 Organic compounds containing a heteroaromatic ring with a triazine skeleton, such as [2-naphthyldi(4,1-phenylene)]bis(4,6-diphenyl-1,3,5-triazine] (abbreviated as TznP2N), are particularly preferred. Furthermore, TznP2N (300), mSbfxBPTzn (302), mpCNBP-SFxTzn (303), CNBPNPTzn (304), βNP-SFx(4)Tzn (305), mmtBuBP-mDMePyPTzn (306), and mBnfBPTzn (307) are particularly preferred.

[0203] [Chemical Formula 11] In addition, the electron transport layer included in the light-emitting unit on the anode side and the electron transport layer included in the light-emitting unit on the cathode side can both be a layer containing a seventh organic compound having a triazine skeleton, or a layer containing an 18th organic compound not having a triazine skeleton.

[0204] To reduce power consumption, the electron transport layer of the light-emitting unit on the anode side preferably contains a seventh organic compound with a triazine framework. In particular, when the seventh organic compound contains the same organic compound as the sixth organic compound, it can prevent the manufacturing apparatus from becoming complicated, and it is also advantageous from the perspective of raw material procurement costs, so it is preferred.

[0205] Furthermore, when the electron transport layer of the light-emitting unit on the anode side comprises an 18th organic compound that does not have a triazine skeleton, the control of carrier transport becomes easier, thereby providing a light-emitting device with better characteristics. As an organic compound that does not contain a triazine skeleton, it is preferable to use an organic compound containing at least one of a pyridine skeleton, a diazine (pyrimidine or pyrazine) skeleton, an imidazole skeleton, and an anthracene skeleton; more preferably, an organic compound containing at least one of a pyrimidine skeleton, an imidazole skeleton, and an anthracene skeleton. Furthermore, it is preferable to use an organic compound containing a heteroaromatic ring with a pyridine skeleton, an organic compound containing a heteroaromatic ring with a diazine (pyrimidine or pyrazine) skeleton, an organic compound containing a heteroaromatic ring with an imidazole skeleton, or an organic compound containing an aromatic ring with an anthracene skeleton. Additionally, organic compounds that are appropriately deuterated from the above-mentioned organic compounds can also be used in the same way.

[0206] To reduce the driving voltage, the electron transport layer in the light-emitting unit on the cathode side preferably further comprises lithium or a lithium compound. Specifically, Li, lithium fluoride (LiF), lithium oxide (Li₂O), and 8-hydroxyquinoline-lithium (Liq) are preferably used as the lithium or lithium compound. Thus, one embodiment of the light-emitting device of the present invention can be a light-emitting device with a low driving voltage.

[0207] Alternatively, the electron transport layer in the light-emitting unit on the cathode side can also employ a stacked structure. In this case, the cathode-side layer of the stacked structure preferably contains a sixth organic compound having a triazine framework, and more preferably, it also contains lithium or a lithium compound. The anode-side layer of the stacked structure preferably contains an eighth organic compound having a triazine framework. The sixth organic compound and the eighth organic compound are preferably the same.

[0208] The fifth organic compound containing the phenanthrene skeleton in the intermediate layer preferably has the following electron transport properties: an electron mobility of 1 × 10⁻⁶ at an electric field strength [V / cm] square root of 600. -7 cm 2 / Vs or more, preferably 1×10 -6cm 2 / Vs or higher. Note that as long as electron transport is higher than hole transport, substances other than those mentioned above can be used.

[0209] As the fifth organic compound having a phenanthrene-coral skeleton, a compound having both a phenanthrene-coral skeleton and an aromatic ring is preferred. As the aromatic ring, a monocyclic aromatic ring, a polycyclic aromatic ring, or the like is preferred.

[0210] Examples of monocyclic aromatic rings include benzene rings, pyrrole rings, pyridine rings, and pyrimidine rings. Furthermore, examples of polycyclic aromatic rings include those with aromatic rings such as naphthalene rings, phenanthrene rings, alkyl rings, triphenylene rings, and fluorene rings, as well as heteroaromatic rings such as phenanthrene-rholine rings and pyrrole rings. In particular, having multiple of the above-mentioned polycyclic aromatic rings can improve heat resistance or electron transport properties, and is therefore preferred.

[0211] As the fifth organic compound with a phenanthrene-coral skeleton, examples include red phenanthrene-coral (BPhen), copper hydroxide (BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthrene-coral (NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthrene-coral) (mPPhen2P), 2-[3-(2-triphenylene)phenyl]-1,10-phenanthrene-coral (mTpPPhen), 2-phenyl-9-( Organic compounds containing heteroaromatic rings with a phenanthrene skeleton, such as 2-triphenylene)-1,10-phenanthroline (abbreviated as Ph-TpPhen), 2-[4-(9-phenanthyl)-1-naphthyl]-1,10-phenanthroline (abbreviated as PnNPhen), and 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviated as pTpPPhen), are preferred, as are PnNPhen (400) and mPPhen2P (401) represented by the following structural formulas (400) or (401).

[0212] [Chemical Formula 12] In one embodiment of the light-emitting device of the present invention, the intermediate layer can have any structure as long as it has a fifth organic compound comprising a phenanthroline skeleton and can inject electrons into the light-emitting units on the anode side and inject holes into the light-emitting units on the cathode side by applying a voltage between the first and second electrodes. Note that the intermediate layer preferably has a stacked structure of a first layer comprising the fifth organic compound and a second layer located closer to the cathode side than the first layer.

[0213] The first layer preferably contains a metal or metal compound in addition to the fifth organic compound. The metal in the metal or metal compound is preferably one of the following elements: alkali metals such as Li (Group 1 elements); alkaline earth metals such as Mg and Ca (Group 2 elements); Group 3 elements including lanthanides such as Y, Eu, and Yb; Group 11 elements such as Cu, Ag, and Au; Group 12 elements such as Zn; and earth metals such as Al and In (Group 13 elements).

[0214] Note that the first layer can have a stacked structure of a layer containing an organic compound and a layer containing a metal or metal compound located closer to the cathode than the layer containing the organic compound. It can also be a mixed layer of organic compound and metal or metal compound. When the first layer is a mixed layer, the number of deposition chambers required can be reduced, thereby reducing manufacturing costs and helping to improve the stability of the light-emitting device, so it is preferred.

[0215] In the case of a mixture of organic compounds and metals or metal compounds, when analyzing the first layer in the thickness direction, the distribution of organic compounds and metals or metal compounds shows roughly the same trend. That is, if the distribution of organic compounds is fixed, the distribution of metals or metal compounds is also roughly fixed. In a stacked structure containing layers of organic compounds and layers containing metals or metal compounds, sometimes metals or metal compounds are detected in areas outside the layers containing those layers due to diffusion. However, because they exhibit a different distribution than the organic compounds, analytical results can be distinguished between diffusion and mixing.

[0216] Furthermore, when analyzing the first layer in the thickness direction, if the thickness of the region where metal or metal compound is detected is 10 nm or more, preferably 15 nm or more, and more preferably 20 nm or more, the first layer may also be considered to be a mixed layer composed of an organic compound and a metal or metal compound.

[0217] In particular, the metal in the aforementioned metal or metal compound is preferably a substance that is a donor to the fifth organic compound. Examples of substances that are donors to the fifth organic compound include metals from Group 1 and Group 2, with lithium or lithium compounds being particularly preferred. Specifically, lithium or lithium compounds such as Li, lithium fluoride (LiF), lithium oxide (Li₂O), and 8-hydroxyquinoline-lithium (Liq) are preferred. When the first layer contains the fifth organic compound and a substance that is a donor to it, electrons are generated through charge separation. When a voltage is applied between the first and second electrodes, these electrons are injected into the light-emitting unit on the anode side through the fifth organic compound. Thus, one embodiment of the light-emitting device of the present invention can be a light-emitting device with a low driving voltage.

[0218] Furthermore, in addition to the organic compounds mentioned above, the fifth organic compound is preferably an organic compound containing a phenanthroline skeleton with electron-donating substituents. The phenanthroline skeleton readily interacts with metals, etc. By further providing an electron-donating group to the fifth organic compound containing such a phenanthroline skeleton, the electron density of the phenanthroline skeleton increases, thereby further facilitating interaction with metals or metal compounds. In particular, when metals from Groups 3, 11, 12, and 13 are used as the metal or metal compound, the rise in driving voltage can be suppressed, thereby providing a tandem light-emitting device with excellent characteristics.

[0219] Specific examples of electron-donating groups include alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino groups. However, the preferred electron-donating group introduced onto the phenanthroline ring is not limited to these. Any group that can increase the electron density of the phenanthroline ring can be used as an electron-donating group. Furthermore, the electron-donating group can also be introduced into the phenanthroline ring via an arylene group such as a p-phenylene group, which is preferably para-phenylene.

[0220] Structural formulas (500) to (511) show specific examples of organic compounds containing a phenanthroline skeleton with electron-donating substituents.

[0221] [Chemical Formula 13] Furthermore, when the first layer comprises a Group 1 or Group 2 organic compound, particularly lithium or a lithium compound, including a fifth organic compound with a phenanthroline skeleton containing electron-donating substituents, it can provide a tandem light-emitting device with lower driving voltage and better reliability, and is therefore preferred. Moreover, when the first layer comprises a Group 1 or Group 2 organic compound, particularly lithium or a lithium compound, including a fifth organic compound with a phenanthroline skeleton containing electron-donating substituents, it can suppress the rise in driving voltage when processing the organic compound layer of the light-emitting device using photolithography, and is therefore preferred.

[0222] In the intermediate layer having the above structure, the fifth organic compound is particularly preferably an organic compound having a 1,10-phenanthroline skeleton in the phenanthroline skeleton, because the two nitrogen atoms contained in the above organic compound can coordinate to a metal, thereby facilitating interaction with the metal or metal compounds.

[0223] When electron-donating groups are introduced into the 1,10-phenanthroline skeleton, these groups are preferably substituted at the 4 and 7 positions. By introducing electron-donating groups at the 4 and 7 positions of the 1,10-phenanthroline skeleton, the electron density of the nitrogen atoms at the 1 and 10 positions can be increased, thereby facilitating interactions with metals or metal compounds.

[0224] The first layer may also contain an organic compound different from the fifth organic compound. Furthermore, this organic compound is preferably an organic compound with electron transport properties. In particular, this organic compound preferably has two or more heteroaromatic rings bonded or fused together, and these two or more heteroaromatic rings have a total of three or more heteroatoms. By including such an organic compound in the first layer, heat resistance and electron transport properties can be improved.

[0225] The second layer preferably comprises a 17th organic compound with hole-transporting properties. Furthermore, the second layer preferably also comprises a receptor-like substance, which is preferably an organic compound that is receptor-like to the 17th organic compound. As the receptor-like substance, an organic compound having at least one of a halogen group and a cyano group is particularly preferred, and an organic compound having at least one of a fluorine group and a cyano group is more preferred. Furthermore, the total number of halogen (fluorine) and cyano groups contained in the organic compound is more preferably four or more.

[0226] In the case where the second layer contains a 17th organic compound and a substance that exhibits acceptor properties to the 17th organic compound, holes are generated through charge separation. When a voltage is applied between the first and second electrodes, these holes are injected into the light-emitting unit on the cathode side through the 17th organic compound. Thus, one embodiment of the light-emitting device of the present invention can be a light-emitting device with a low driving voltage.

[0227] The intermediate layer can also include a third layer between the first and second layers.

[0228] The third layer contains an electron-transmitting material and has the function of smoothly transferring electrons between the first and second layers to reduce the driving voltage, as well as reducing the interaction between the first and second layers to improve reliability.

[0229] Furthermore, the thickness of the third layer is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 5 nm or less, thereby suppressing the rise of the driving voltage.

[0230] The light-emitting device of the present invention having the above-described structure can be a light-emitting device with high current efficiency, low energy loss, and good characteristics. Furthermore, a display device using such a light-emitting device according to one aspect of the present invention can be a display device with low power consumption, high reliability, and good visibility, capable of displaying at high brightness.

[0231] Next, a light-emitting device according to one aspect of the present invention will be described in detail with reference to the accompanying drawings. Figure 1AA light-emitting device 130 according to one embodiment of the present invention is shown. One embodiment of the light-emitting device is a series-connected light-emitting element comprising an organic compound layer 103 (also referred to as an EL layer) between a first electrode 101 including an anode and a second electrode 102 including a cathode. The organic compound layer 103 includes a first light-emitting unit 501 having a first light-emitting layer 113_1, a second light-emitting unit 502 having a second light-emitting layer 113_2 and a second electron transport layer 114_2, and an intermediate layer 116. Alternatively, the first light-emitting unit may also include a first electron transport layer 114_1 between the first light-emitting layer 113_1 and the intermediate layer 116.

[0232] In the light-emitting device 130, the second electron transport layer 114_2 contains a sixth organic compound having a triazine framework, and the intermediate layer 116 contains a fifth organic compound having a phenanthroline framework. Furthermore, to reduce power consumption, the second electron transport layer 114_2 containing the sixth organic compound having a triazine framework is preferably in contact with the second electrode 102.

[0233] In this embodiment, a light-emitting device comprising one intermediate layer 116 and two light-emitting units is used as an example. However, a light-emitting device comprising n (n is an integer greater than or equal to 1) intermediate layers and n+1 light-emitting units can also be used. For example, Figure 1B The light-emitting device 130 shown is an example of a series-connected light-emitting device with n=2, including a first light-emitting unit 501, a first intermediate layer 116_1, a second light-emitting unit 502, a second intermediate layer 116_2, and a third light-emitting unit 503.

[0234] The first light-emitting unit 501 and the second light-emitting unit may also include other functional layers besides the aforementioned light-emitting layer and electron transport layer. Figure 1A In the first light-emitting unit 501, in addition to the first light-emitting layer 113_1 and the first electron transport layer 113_1, a hole injection layer 111 and a first hole transport layer 112_1 are also provided. Similarly, in the second light-emitting unit 502, in addition to the second light-emitting layer 113_2 and the second electron transport layer 114_2, a second hole transport layer 112_2 is also provided. However, the structure of the organic compound layer 103 of the present invention is not limited to this; any of the aforementioned layers may be omitted, or other layers may be provided. Typical examples of other layers include carrier blocking layers, exciton blocking layers, etc.

[0235] The first electrode 101 is an electrode including an anode. The first electrode 101 may also employ a multilayer structure, in which case the layer in contact with the organic compound layer 103 serves as the anode. The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof with a high work function (specifically 4.0 eV or higher). Specifically, examples include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). While these conductive metal oxide films are typically formed by sputtering, sol-gel methods can also be used. As an example of a formation method, a method using a target with 1 wt% to 20 wt% zinc oxide added to indium oxide to form indium oxide can be described by sputtering. Furthermore, indium oxide (IWZO) containing tungsten oxide and zinc oxide can be formed by sputtering using a target containing 0.5 wt% to 5 wt% tungsten oxide and 0.1 wt% to 1 wt% zinc oxide. Other materials that can be used as the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride). Graphene can also be used as the anode material. Furthermore, by using the composite material constituting the second layer 117 of the aforementioned intermediate layer 116 as the layer in contact with the anode (typically a hole injection layer), the work function can be disregarded when selecting the electrode material.

[0236] Hole injection layer 111 is in contact with the anode and has the function of easily injecting holes into organic compound layer 103 (first light-emitting unit 501). Hole injection layer 111 can be formed by using phthalocyanine compounds or complexes such as phthalocyanine (H2Pc), copper phthalocyanine (CuPc), etc.; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (DNTPD), etc.; or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (PEDOT / PSS), etc.

[0237] Furthermore, the hole injection layer 111 can also be composed of a substance with electron-accepting properties. As such, organic compounds with electron-withdrawing groups (halogen groups, cyano groups, etc.) can be used, including 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethylethane (abbreviated: F4-TCNQ), chloroquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated: F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-yl)malononitrile, etc. In particular, compounds such as HAT-CN, which have electron-withdrawing groups bonded to fused aromatic rings with multiple heteroatoms, are thermally stable and therefore preferred. Furthermore, [3] axylene derivatives containing electron-withdrawing groups (especially halogen groups such as fluorine groups, cyano groups, etc.) are preferred due to their very high electron acceptor properties. Specifically, examples include: α,α',α''-1,2,3-cyclopropanetrimethylenetri[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], and α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,3,4,5,6-pentafluorophenylacetonitrile]. In addition to the aforementioned organic compounds, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used as acceptor substances. Furthermore, a hole injection layer 111 can be formed by using phthalocyanine compounds or complexes such as phthalocyanine (H2Pc), copper phthalocyanine (CuPc), etc.; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (DNTPD), etc.; or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (PEDOT / PSS), etc. Substances with acceptor properties can extract electrons from adjacent hole transport layers (or hole transport materials) by means of an applied electric field.

[0238] Furthermore, the hole injection layer 111 is preferably formed of a composite material comprising the aforementioned acceptor material and a hole transport substance.

[0239] Various organic compounds, such as aromatic amines, heteroaromatic compounds, aromatic hydrocarbons, and polymers (oligomers, dendritic polymers, polymers, etc.), can be used as hole-transporting materials for composite materials. Furthermore, a hole mobility of 1×10⁻⁶ is preferred. -6 cm 2 Substances with a density of / Vs or higher. Substances with hole-transporting properties used in composite materials are preferably compounds comprising fused aromatic rings or π-electron-rich heteroaromatic rings. As fused aromatic rings, anthracene rings, naphthalene rings, etc., are preferred. Furthermore, as π-electron-rich heteroaromatic rings, fused aromatic rings having at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton are preferred; specifically, carbazole rings, dibenzothiophene rings, or rings fused with these rings to aromatic or heteroaromatic rings are preferred.

[0240] More preferably, such hole-transporting substances have at least one of a carbazole backbone, a dibenzofuran backbone, a dibenzothiophene backbone, and an anthracene backbone. In particular, they can be aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines including a naphthyl ring, or aromatic monoamines in which a 9-fluorene group is bonded to the nitrogen of the amine via an arylene group. Note that when these hole-transporting substances are N,N-bis(4-biphenyl)amino groups, long-lifetime light-emitting devices can be manufactured, and therefore they are preferred. Furthermore, by having multiple of the above-mentioned backbones, hole transport can be improved or adjusted.

[0241] Specifically, examples of substances with hole transport capabilities include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviated as: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviated as: BBABnf(6)), and N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviated as: BBABnf(6)). -d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-benzidine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-di Phenylacetyl-4''-(6;1'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binathyl) -1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-Bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tri(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviation: PCB) NBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirodi[9H-fluorene]-4-amine (abbreviated as: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi[9H-fluorene]-4-amine (abbreviated as: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)dibenzofuran-4-amine (abbreviated as: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthalene 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluorene-9-yl)phenyl]triphenylamine (abbreviated as: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBA1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBANBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBiF), N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviated as: PSiCzCz), 9'-[phenyl]-9'H-9,3':6',9''-tricarbazole (abbreviated as: PSiCzGI), N-(biphenyl-2-yl)-N-(9,9-dimethylfluorene-2-yl)-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as: oFBiSF(2)), etc.

[0242] In addition, as substances with hole transport capabilities, the following aromatic amine compounds can also be used: N,N'-bis(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B), etc.

[0243] By forming a hole injection layer 111, hole injection capability can be improved, thereby obtaining a light-emitting device with low driving voltage.

[0244] Furthermore, in substances with receptors, organic compounds with receptors can be easily deposited using vapor deposition, making them easy-to-use materials.

[0245] The hole transport layers (first hole transport layer 112_1, second hole transport layer 112_2) are formed by comprising an organic compound with hole transport properties. Preferably, the organic compound with hole transport properties has a content of 1×10⁻⁶. -6 cm 2 Hole mobility of / Vs or higher. Furthermore, as an organic compound with hole transport capability, an organic compound having an aromatic amine skeleton is preferred. Examples of aromatic rings in organic compounds having an aromatic amine skeleton include monocyclic aromatic rings and polycyclic aromatic rings. In addition, these aromatic rings may also have alkyl groups as substituents.

[0246] Examples of monocyclic aromatic rings include benzene rings and other aromatic rings, as well as heterocyclic aromatic rings such as pyrrole rings and furan rings. The presence of an aromatic ring as a substituent improves heat resistance, thereby increasing the glass transition temperature (Tg). Furthermore, the presence of an aromatic ring as a substituent also improves the transport properties of charge carriers such as holes and electrons. Moreover, having multiple monocyclic aromatic rings can further increase Tg; for example, a biphenyl or terphenyl structure is preferred, but a p-phenylene, m-phenylene, or ortho-phenylene structure is also acceptable. Having at least one of the m-phenylene and ortho-phenylene structures not only improves the solubility of the compound, making manufacturing easier, but also reduces the refractive index. Furthermore, when the compound has three or more benzene rings, such as a terphenyl structure, including an aromatic ring with at least two of the p-phenylene, m-phenylene, and ortho-phenylene structures is preferred, as it adjusts not only solubility and refractive index but also the transport properties of charge carriers.

[0247] Note that when the benzene ring is used as a linker, it is usually called phenylene, but to avoid complexity, it is sometimes called phenyl even when used as a linker. The same applies to other aromatic rings; when used as a linker, they are sometimes called aryl instead of arylene, or sometimes heteroarylene instead of heteroarylene. Additionally, the description of the benzene ring is sometimes replaced with "benzene structure" or "benzene skeleton," and other substituents (aromatic rings, etc.) are also referred to using this replacement.

[0248] Examples of polycyclic aromatic rings include naphthalene rings, phenanthrene rings, phenanthrene rings, triphenylene rings, fluorene rings, spirodifluorene rings, carbazole rings, dibenzofuran rings, dibenzothiophene rings, and xanthene rings. Compounds with polycyclic aromatic rings as substituents are preferred because they offer improved heat resistance compared to compounds with monocyclic aromatic rings. Furthermore, it is preferable to have multiple of the aforementioned polycyclic aromatic rings. When multiple polycyclic aromatic rings are present, they can be identical or different. When using the same ring, examples include structures with multiple aromatic rings, structures with multiple heterocyclic aromatic rings, and structures with one or more aromatic rings and one or more heterocyclic aromatic rings. In the case of multiple polycyclic aromatic rings, these rings can be identical or different. Using the same aromatic ring can lead to reduced raw material costs and simplified synthesis processes. Additionally, when using different aromatic rings, the transport properties of charge carriers such as holes or electrons, or the heat transfer rate (Tg), can be adjusted depending on the type of aromatic ring used. Examples of structures with multiple polycyclic aromatic rings include those with carbazole and dibenzofuran rings, structures with two, three, or more carbazole rings, and structures with two, three, or more fluorene rings.

[0249] Furthermore, in compounds in which the aforementioned polycyclic aromatic ring is fused with an aromatic ring (such as the aforementioned monocyclic aromatic ring), the heat resistance can be further improved. Examples of polycyclic aromatic rings fused with aromatic rings include benzo[a]fluorene ring, benzo[a]naphthofuran ring, benzo[a]oxanthracene ring, and benzo[a]naphthothiophene ring.

[0250] Furthermore, both monocyclic aromatic rings and polycyclic aromatic rings described above can be used as substituents. Examples include structures where a monocyclic aromatic ring is used as a linker between the nitrogen in the amine skeleton and the polycyclic aromatic ring. For instance, structures using a phenylene ring between the nitrogen and fluorene ring, structures using a phenylene ring between the nitrogen and carbazole ring, or structures using a phenylene ring between the nitrogen and dibenzo[a]fluorene ring are also examples. Additionally, structures in which multiple polycyclic aromatic rings are bonded to a single phenylene ring used as a linker are also effective. These multiple polycyclic aromatic rings can be the same aromatic ring or different aromatic rings. For example, in compounds where both the carbazole ring and the dibenzo[a]fluorene ring are bonded to a single phenylene ring, the functions of both the carbazole ring and the dibenzo[a]fluorene ring can be obtained while simultaneously increasing the temperature gradient (Tg).

[0251] Furthermore, examples of alkyl groups include methyl, ethyl, propyl, tert-butyl, cyclohexyl, and adamantyl. Using a layer with a compound having alkyl groups as substituents can reduce the refractive index. Therefore, total internal reflection at the interface between this layer and other layers can be reduced, thereby improving light extraction efficiency. Furthermore, by also using the aforementioned substituent-containing compounds in the hole transport layer, the refractive index of the hole transport layer can be reduced. In particular, by using compounds having an aromatic amine skeleton and alkyl groups in the hole transport layer, the effect of improving light extraction efficiency can be multiplied and enhanced. Additionally, when the number of carbon atoms in the alkyl group in the organic compound is multiple, preferably three or more, more preferably four or more, and even more preferably five or more, the effect of reducing the refractive index can be improved. Furthermore, when multiple alkyl groups are bonded to one aromatic ring, the refractive index can be further reduced, which is preferred. In this case, the multiple alkyl groups can be the same or different. For example, one benzene ring can be bonded to two or three tert-butyl groups. Furthermore, in the case of multiple aromatic rings, when alkyl groups are bonded to two or more aromatic rings, the refractive index can be reduced. Furthermore, by having alkyl groups in a portion of the multiple aromatic rings, the refractive index can be adjusted. For example, in the case of three aromatic rings, structures in which two aromatic rings have alkyl groups and the other aromatic ring does not have an alkyl group can be cited.

[0252] Examples of the aforementioned hole-transporting organic compounds include: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (TPD), N,N'-bis(9,9'-spirobis[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine. Triphenylamine (abbreviated as: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCCNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluorene-2-amine (abbreviated as: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H Compounds with aromatic amine skeletons, such as fluorene-2-amine (abbreviated as PCBASF); 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviated as PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviated as PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as PCCzBP) Named as: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-Bicarbazole (abbreviated as: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H, 9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H, 9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H, 9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H, 9'H-bicarbazole Carbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviated as: PCCzTp), 9,9'-bis(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenyl-2-yl)- Compounds with a carbazole skeleton, such as 9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirodi-9H-fluoren-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviated: PSiCzCz), 9'-phenyl-9'H-9,3':6',9''-tricarbazole (abbreviated: PSiCzGI); 4,4',4''-(benzyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated: DBT3P-II), 2 Compounds with a thiophene skeleton, such as 8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV); and compounds with a furan skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among these, compounds with an aromatic amine skeleton and compounds with a carbazole skeleton are preferred due to their high reliability, excellent hole transport properties, and ability to reduce driving voltage. Furthermore, organic compounds, which are examples of materials with hole transport properties and are used as composite materials for the hole injection layer 111, can also be suitably used as materials constituting the hole transport layer 112. In addition,Alternatively, appropriately deuterated organic compounds can be used in the same way.

[0253] Furthermore, the first hole transport layer 112_1 and the second hole transport layer 112_2 preferably contain organic compounds with the same backbone, and more preferably contain the same compound. Additionally, one or both of the first hole transport layer 112_1 and the second hole transport layer 112_2 may also employ a stacked structure. By employing a stacked structure as the hole transport layer 112 and using an organic compound with high electron resistance and / or an organic compound with electron blocking properties (i.e., a ninth organic compound) in the layer adjacent to the light-emitting layer 113, a light-emitting device with high reliability can be obtained. When the hole transport layer 112 employs a stacked structure, a material with high hole transport, low electron transport, and a high LUMO energy level is preferably used as the layer adjacent to the light-emitting layer 113. This material is preferably a material whose LUMO energy level is higher than that of the material with the highest composition ratio among the materials constituting the light-emitting layer or the material with the highest LUMO energy level among the materials constituting the light-emitting layer, preferably a material that is 0.30 eV higher or more. This material is preferably an organic compound having an amine backbone and a polycyclic aromatic ring, and more preferably an organic compound having an amine backbone and a furan backbone or a dibenzofuran backbone. When the hole transport layer 112 adopts a stacked structure, by using the aforementioned ninth organic compound as a layer close to the light-emitting layer 113, electrons can be prevented from passing through the first electrode 101 side from the light-emitting layer 113, thereby enabling the manufacture of a display device with high efficiency and long lifespan. Note that the layer closer to the first electrode 101 in the hole transport layer 112 with the stacked structure preferably uses a tenth organic compound having an amine backbone and polycyclic aromatic hydrocarbons, and more preferably uses an organic compound having an amine backbone and a fluorene backbone. Organic compounds having amine backbones and fluorene backbones have high reliability and high hole transport properties, thus reducing the power consumption of the light-emitting device, and are therefore preferred.

[0254] As an organic compound having an aromatic amine skeleton, it is preferred to use an organic compound represented by the following structural formulas (600) to (630). Particularly preferred are BBASF (4) as shown in structural formula (600), oBBASF as shown in structural formula (601), BBAFLP (4) as shown in structural formula (602), oFBiSF (2) as shown in structural formula (603), FBiSF (4) as shown in structural formula (604), oFBiSF as shown in structural formula (605), FBimFLP as shown in structural formula (606), FBimMemFLP as shown in structural formula (607), SF (4)FAF as shown in structural formula (608), FrBBiFLP as shown in structural formula (609), tBu-oFBiSF (2) as shown in structural formula (610), FBiFLPB as shown in structural formula (611), DBfBBFLP (2) as shown in structural formula (612), FLP2oBP as shown in structural formula (613), PCAFLP (2)-02 as shown in structural formula (614), and structural formula (615). 15) tBu2FoFBi, oFrTPPnox as shown in formula (616), mPDBfBNBN as shown in formula (617), BBAaBnf (7) as shown in formula (618), DBfBB1TP as shown in formula (619), BOx3Am as shown in formula (620), BBA2BP as shown in formula (621), PCBBi1BP as shown in formula (622), YGBBi1BP-02 as shown in formula (623), YGBBi1BP as shown in formula (624), PCBBi1TP as shown in formula (625), YGBBiPDBf as shown in formula (626), BPPCA as shown in formula (627), PCBBiF as shown in formula (628), DBf-YGBBi1BP as shown in formula (629), and YGTPDBfB as shown in formula (630).

[0255] [Chemical Formula 14] [Chemical Formula 15] [Chemical Formula 16] [Chemical Formula 17] For example, as hole transport layers 112_1a and 112_2a, organic compounds having an amine skeleton and polycyclic hydrocarbons are preferably used among the organic compounds shown in structural formulas (600) to (630), and organic compounds having an amine skeleton and fluorene skeleton are even more preferred.

[0256] Furthermore, as hole transport layers 112_1b and 112_2b, organic compounds having an amine backbone and a furan backbone or a dibenzofuran backbone are preferably used among the organic compounds shown in structural formulas (600) to (630), and organic compounds having an amine backbone and a furan ring or a dibenzofuran ring are even more preferred. Additionally, organic compounds with a higher LUMO energy level than the material constituting the light-emitting layer (at least the host material, preferably the material constituting the light-emitting layer) can be appropriately selected.

[0257] The light-emitting layers (first light-emitting layer 113_1 and second light-emitting layer 113_2) preferably comprise a light-emitting center material and a host material. Furthermore, at least one of the light-emitting layers has a structure comprising the aforementioned fluorescent light-emitting material, the first host material, and the second host material; preferably, both the first light-emitting layer 113_1 and the second light-emitting layer 113_2 have this structure. In addition, the light-emitting layers may also comprise other materials.

[0258] Furthermore, the first light-emitting layer 113_1 and the second light-emitting layer 113_2 are preferably light-emitting layers that emit light in similar colors. For example, in display devices, red, green, and blue pixels are mostly used to display full color. In light-emitting devices used for red pixels, both the first light-emitting layer 113_1 and the second light-emitting layer 113_2 emit light in a red hue; in light-emitting devices used for green pixels, both light-emitting layers emit light in a green hue; and in light-emitting devices used for blue pixels, both light-emitting layers emit light in a blue hue. In this case, the light-emitting center material contained in the first light-emitting layer 113_1 and the light-emitting center material contained in the second light-emitting layer 113_2 are preferably compounds whose maximum peak wavelength difference in emission spectrum is 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less. Furthermore, it is more preferable that the light-emitting center material (fluorescent material) contained in the first light-emitting layer 113_1 is the same as the light-emitting center material (fluorescent material) contained in the second light-emitting layer 113_2. Furthermore, more preferably, the material constituting the first light-emitting layer 113_1 is the same as the material constituting the second light-emitting layer 113_2.

[0259] Examples of fluorescent luminescent materials that can be used in the luminescent layer include the following. In addition, other fluorescent luminescent materials can also be used.

[0260] Examples include 5,6-bis[4-(10-phenyl-9-anthrayl)phenyl]-2,2'-bipyridine (abbreviated as PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthrayl)biphenyl-4-yl]-2,2'-bipyridine (abbreviated as PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6mMemFLPAPrn), and N,N'-bis[4-(9H-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6mMemFLPAPrn). [-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthrayl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), dinaphthalene, 2,5,8,11-tetra-tert-butyl dinaphthalene (abbreviation: TBP), 4-(10-phenyl-9-anthrayl)-4'-(9-phenyl-9H-carbazole-9- ... N,N''-(2-tert-butylanthracene-9,10-diyl-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenylenediamine) (DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-9H-carbazole-3-amine (2PCAPPA), N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (2DPAPPA), N,N,N',N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p](chrys) N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as: 2PCABPhA), N-(9,10-diphenyl-2-anthrayl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as: 2DPABPhA), 9,10-Bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetraphenyl (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-yl)malonitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H, 5H-benzo[ij]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCM2), N,N,N',N'-tetra(4-methylphenyl)tetraphenyl-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetra(4-methylphenyl)acenaphthene[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJT) I) 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malonium (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: BisDCJ) TM), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazole-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, 1,6FLPAPrn, 1,6mMemFLPAPrn, 1,Fused aromatic diamine compounds, such as pyrene diamine compounds like 6BnfAPrn-03, possess high hole-trapping properties and exhibit high luminous efficiency or high reliability, making them a preferred choice.

[0261] In the case where only one of the first luminescent layer 113_1 and the second luminescent layer 113_2 has the structure described above, the other luminescent layer may contain a luminescent center material other than a fluorescent luminescent material. In this case, the luminescent center material may be a fluorescent luminescent material, a phosphorescent luminescent material, a material exhibiting thermally activated delayed fluorescence (TADF), or other luminescent materials.

[0262] Phosphorescent materials that can be used as luminescent centers include, for example, the following substances.

[0263] Examples include organometallic iridium complexes with a 4H-triazole skeleton, such as {2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as [Ir(mpptz-dmp)3]) and tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Mptz)3]). Compounds; organometallic iridium complexes with a 1H-triazole skeleton, such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(Mptz1-mp)3]) and tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Prptz1-Me)3]); fac-tris[1-(2,6-diisopropyl] [Ir(iPrpim)3][3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviated as [Ir(dmpimpt-Me)3]), [2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazo-2-yl-κ] Organometallic iridium complexes with an imidazole skeleton, such as N3}-4-cyanophenyl-κC)iridium(III) (abbreviated as CNImIr); organometallic complexes with a benzimidazole skeleton, such as tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviated as [Ir(cb)3]); and bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 Iridium(III) tetra(1-pyrazolyl)borate (abbreviated as: FIr6), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2'] Iridium(III) pyridine carboxylate (abbreviated as: FIRpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2 Iridium(III)pyridinecarboxylate (abbreviated as: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 Organometallic iridium complexes such as iridium(III) acetylacetone (abbreviated as FIracac) with phenylpyridine derivatives having electron-withdrawing groups as ligands; and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviated as PtON-TBBI). These substances are compounds that emit a blue phosphorescent light and have emission peaks in the wavelength region of 450 nm to 520 nm. Additionally, compounds in which a portion of the hydrogen is replaced with deuterium can also be used.

[0264] In addition to tris(4-methyl-6-phenylpyrimidinium)iridium(III) (abbreviated as [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidinium)iridium(III) (abbreviated as [Ir(tBuppm)3]), (acetylacetonium)bis(6-methyl-4-phenylpyrimidinium)iridium(III) (abbreviated as [Ir(mppm)2(acac)]), (acetylacetonium)bis(6-tert-butyl-4-phenylpyrimidinium)iridium(III) (abbreviated as [Ir(tBuppm)2(acac)]), (acetylacetonium)bis[6-(2-norbornyl)-4-phenylpyrimidinium]iridium(III) (abbreviated as [Ir(nbppm)2(acac)]), (acetylacetonium)bis[5-methyl-6- Organometallic iridium complexes with a pyrimidine skeleton, such as (2-methylphenyl)-4-phenylpyrimidinium[Ir(mpmppm)2(acac)] and (acetylacetonate)bis(4,6-diphenylpyrimidinium)iridium[Ir(dppm)2(acac)]; organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonate)bis(3,5-dimethyl-2-phenylpyrazine)iridium[Ir(mppr-Me)2(acac)] and (acetylacetonate)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium[Ir(mppr-iPr)2(acac)]; and tris(2-phenylpyridinium-N,C 2’ Iridium (III) (abbreviated as: [Ir(ppy)3]), bis(2-phenylpyridinium-N,C) 2’Iridium (III) acetylacetone (abbreviated as: [Ir(ppy)2(acac)]), bis(benzo[h]quinoline)iridium (III) acetylacetone (abbreviated as: [Ir(bzq)2(acac)]), tri(benzo[h]quinoline)iridium (III) (abbreviated as: [Ir(bzq)3]), tri(2-phenylquinoline-N,C 2’ Iridium (III) (abbreviated as: [Ir(pq)3]), bis(2-phenylquinoline-N,C) 2’Iridium (III) acetylacetone (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium (III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridyl-κN]benzofurano[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridyl-κN]phenyl-κC} Iridium (III) (abbreviated as: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (III) (abbreviated as: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (III) (abbreviated as: Ir(ppy)2(mdppy)), [2-(4-d3-methyl-5-phenyl-2-pyridyl-κN2 ...mbfpypy-d4)]iridium (III) (abbreviated as: Ir(ppy)2(mbfpypy-d4)]iridium (III) [C]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviated as: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: [Ir(ppy)2(mbfpypy)]), [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (abbreviated as: [Ir(ppy)2(mdppy)]), tri{2-[5-(methyl-8-(2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (abbreviated as: [Ir(ppy)2(mdppy)]), tri{2-[5-(methyl-8-(2-pyridyl-κN)phenyl-κC]iridium(III) ... Besides organometallic iridium complexes with a pyridine skeleton, such as (2-{1-(5-tert-butylbiphenyl-2-yl)-4-[3-tert-butyl-5-(4-phenyl-2-pyridyl-κN)phenyl-κC6]-2-benzimidazolyl-κN3}-4,6-di-tert-butylphenol-κO)platinum (II) (Pt(tBudppymmtBubiz-tBubp)), [2-(4-(3,5-di-tert-butylphenyl)-6-{3-[4-(5'-tert-butyl[1,1':3',Organometallic platinum complexes such as [1''-terphenyl]-2'-yl)-2-pyridyl-κN]phenyl-κC2}-2-pyridyl-κN)phenol-κO]platinum(II) (abbreviated as Pt(4tButpppypyp-mmtBup)) and rare earth metal complexes such as tri(acetylacetone)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]) are used. These substances are primarily phosphorescent compounds exhibiting a green phase and possessing emission peaks in the 500 nm to 600 nm wavelength region. Furthermore, organometallic iridium complexes with a pyrimidine skeleton are particularly preferred due to their exceptionally superior reliability or luminescence efficiency. Alternatively, compounds in which a portion of the hydrogen atoms is replaced with deuterium can also be used.

[0265] In addition, examples of organogold compounds with a pyrimidine skeleton include: (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinyl]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinyl](dineopentylmethane)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), and bis[4,6-bis(naphth-1-yl)pyrimidinyl](dineopentylmethane)iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]). Organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonate)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dinepentanoylmethane)iridium(III) (abbreviated as [Ir(tppr)2(dpm)]), and (acetylacetonate)bis[2,3-bis(4-fluorophenyl)quinoxaloline]iridium(III) (abbreviated as [Ir(Fdpq)2(acac)]); tris(1-phenylisoquinoline-N,C 2’ Iridium (III) (abbreviated as: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C) 2’Organometallic iridium complexes with a pyridine skeleton include iridium(III) acetylacetone (abbreviated as: [Ir(piq)2(acac)]), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). The compounds include platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP); and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato) (monopraninol) europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenecarboxyl)-3,3,3-trifluoroacetone] (monopraninol) europium(III) (abbreviated as [Eu(TTA)3(Phen)]). These substances are phosphorescent compounds exhibiting a red phase and possessing an emission peak in the wavelength region of 600 nm to 700 nm. Furthermore, organometallic iridium complexes with a pyrazine skeleton can provide red luminescence with good colorimetry. Additionally, compounds in which a portion of the hydrogen is replaced with deuterium can also be used.

[0266] Furthermore, in one aspect of the present invention, the luminescence efficiency is improved by using a deuterated compound as the luminescent center material. Therefore, the luminescent center material is preferably a deuterated material.

[0267] In addition to the phosphorescent compounds mentioned above, other known phosphorescent compounds may also be used.

[0268] When TADF materials are used as luminescent centers, fullerenes and their derivatives, acridines and their derivatives, and eosin derivatives can be used as TADF materials. In addition, metal porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can also be cited. Examples of metalloporphyrins include protoporphyrin-tin fluoride complexes (SnF2(Proto IX)), mesoporphyrin-tin fluoride complexes (SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (SnF2(Hemato IX)), tetramethyl coprophyrin-tin fluoride complexes (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (SnF2(OEP)), protoporphyrin-tin fluoride complexes (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (PtCl2OEP), all represented by the following structural formulas.

[0269] [Chemical Formula 18] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindol[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviated as: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1, Heterocyclic compounds such as 3,5-triazine (PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthracene-9-one (ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (ACRSA) possessing one or both π-electron-rich and π-electron-deficient heterocyclic rings are preferred. These heterocyclic compounds exhibit high electron and hole transport properties due to the presence of both π-electron-rich and π-electron-deficient heterocyclic rings. Among the skeletons with π-electron-deficient heteroaromatic rings, pyridine, diazine (pyrimidine, pyrazine, pyridazine), and triazine skeletons are stable and reliable, and are therefore preferred. In particular, benzofuran-pyrimidine, benzothiophene-pyrimidine, benzofuran-pyrazine, and benzothiophene-pyrazine skeletons are highly acceptor and reliable, and are therefore preferred. Furthermore, among the skeletons with π-electron-rich heteroaromatic rings, acridine, phenoxazine, phenothiazine, furan, thiophene, and pyrrole skeletons are stable and reliable, and are therefore preferred to have at least one of these skeletons. Moreover, dibenzofuran skeletons are preferred as furan skeletons, and dibenzothiophene skeletons are preferred as thiophene skeletons. As pyrrole skeletons, indole, carbazole, indole-carbazole, bicarbazole, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeletons are particularly preferred. In substances where π-electron-rich and π-electron-deficient heteroaromatic rings are directly bonded, the π-electron-rich heteroaromatic ring exhibits high electron-donating and electron-accepting properties, while the energy difference between the S1 and T1 energy levels decreases, resulting in highly efficient thermally activated delayed fluorescence. Therefore, it is particularly preferred. Note that aromatic rings bonded with electron-withdrawing groups such as cyano groups can also be used instead of π-electron-deficient heteroaromatic rings. Furthermore, aromatic amine skeletons, phenazine skeletons, etc., can be used as π-electron-rich skeletons.Furthermore, as π-electron-deficient skeletons, the following can be used: oxanthracene skeleton, thioxanthene dioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, boron-containing skeletons such as phenylborane or boranthrene, aromatic or heteroaromatic rings with nitrile or cyanobenzene, carbonyl skeletons such as benzophenone, phosphine oxide skeleton, sulfone skeleton, etc. Thus, π-electron-deficient and π-electron-rich skeletons can be used to replace at least one of the π-electron-deficient and π-electron-rich heteroaromatic rings.

[0270] [Chemical Formula 19] Furthermore, TADF materials that are in thermal equilibrium between singlet and triplet excited states can also be used as TADF materials. Because of their short luminescence lifetime (excitation lifetime), these TADF materials can suppress efficiency degradation in the high-brightness region of light-emitting devices. Specifically, materials with the following molecular structures can be cited as examples.

[0271] [Chemical Formula 20] Furthermore, TADF materials refer to materials with a small energy difference between the S1 and T1 levels and the ability to convert triplet excitation energy into singlet excitation energy through antisystem crossing. Therefore, they can efficiently generate singlet excited states by up-converting triplet excitation energy to singlet excitation energy (antisystem crossing) with minimal thermal energy. Additionally, triplet excitation energy can be converted into luminescence.

[0272] Exciplexes formed by two substances in an excited state have the ability to convert triplet excitation energy into singlet excitation energy due to the extremely small difference between the S1 and T1 energy levels.

[0273] Note that the phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) can be used as an indicator of the T1 energy level. For TADF materials, it is preferable that the difference between S1 and T1 is 0.3 eV or less, more preferably 0.2 eV or less, when the wavelength energy of the extrapolated line obtained by tangenting at the short wavelength side of the fluorescence spectrum is taken as the S1 energy level and the wavelength energy of the extrapolated line obtained by tangenting at the short wavelength side of the phosphorescence spectrum is taken as the T1 energy level.

[0274] Furthermore, when using TADF material as the luminescent material, the S1 energy level of the host material is preferably higher than that of the TADF material. Additionally, the T1 energy level of the host material is preferably higher than that of the TADF material.

[0275] Regarding the host material, since the structures of the luminescent layers disclosed above (including the structures of the fluorescent luminescent material, the first host material, and the second host material) have been described in detail, a repetition of the description is omitted. In luminescent layers without this structure, various carrier transport materials, such as organic compounds with electron transport properties and / or organic compounds with hole transport properties, can be used as the host material.

[0276] As an organic compound with hole transport capability, it is preferable to use an organic compound having an amine skeleton, a π-electron-rich heteroaromatic ring skeleton, etc. As a π-electron-rich heteroaromatic ring, it is preferably a fused aromatic ring having at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton, specifically preferably a carbazole ring, a dibenzothiophene ring, or a ring that is also fused with an aromatic ring or a heteroaromatic ring.

[0277] More preferably, the hole-transporting material described above is one having at least one of a carbazole backbone, a dibenzofuran backbone, a dibenzothiophene backbone, and an anthracene backbone. In particular, it can be an aromatic amine having substituents including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthyl ring, or an aromatic monoamine in which a 9-fluorene group is bonded to the nitrogen of the amine via an arylene group. Note that when these hole-transporting materials are organic compounds having an N,N-bis(4-biphenyl)amino group, long-lifetime light-emitting devices can be manufactured, and therefore they are preferred. Furthermore, by having multiple of the above-described backbones, hole transport can be improved or adjusted.

[0278] As such organic compounds, the following organic compounds are preferred, for example: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobis[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBA) 1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCCNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine ( Compounds with aromatic amine skeletons, such as PCBASF; 1,3-bis(N-carbazolyl)benzene (mCP), 4,4'-bis(N-carbazolyl)biphenyl (CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (PCCP), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (Bi) sBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-Bicarbazole (abbreviated as: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H, 9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H, 9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H, 9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H, 9'H-bicarbazole Carbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviated as: PCCzTp), 9,9'-bis(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenyl-2-yl)- Compounds with a carbazole skeleton, such as 9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviated: PSiCzCz), and 9'-phenyl-9'H-9,3':6',9''-terphenylcarbazole (abbreviated: PSiCzGI); 4,4',4''-(benzyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated: DBT3P-II), Compounds with a thiophene skeleton, such as 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV); and compounds with a furan skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among these, compounds with an aromatic amine skeleton or a carbazole skeleton are preferred due to their high reliability, excellent hole transport properties, and ability to help reduce the driving voltage. Furthermore, organic compounds with hole transport properties, exemplified as materials for hole transport layers, can also be used.

[0279] As an organic compound with electron transport capabilities, an organic compound containing a π-electron-deficient heteroaromatic ring is preferred. Examples of organic compounds containing a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring with a polyazole skeleton, organic compounds containing a heteroaromatic ring with a pyridine skeleton, organic compounds containing a heteroaromatic ring with a diazine skeleton, and organic compounds containing a heteroaromatic ring with a triazine skeleton.

[0280] Organic compounds containing heteroaromatic rings with a diazine (pyrimidine, pyrazine, or pyridazine) skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings with a triazine skeleton exhibit high electron transport properties, which helps to reduce the driving voltage. Furthermore, benzofuran-pyrimidine skeletons, benzothiophene-pyrimidine skeletons, benzofuran-pyrazine skeletons, and benzothiophene-pyrazine skeletons are preferred due to their high acceptor activity and reliability.

[0281] As organic compounds with a π-electron-deficient heteroaromatic ring skeleton, the following organic compounds are preferred, for example: 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated: PBD), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated: CO11), 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated: TPBI), 2-[3-(diphenyltriyl)-5-(4 ...phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5-(4-phenyltriyl)-5- Organic compounds with an azole skeleton, such as benzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II) and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs); 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), phenanthroline (abbreviation: Bphen), copper hydroxide (abbreviation: BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'- Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as (1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), 2-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviated as mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviated as Ph-TpPhen), 2-[4-(9-phenanthyl)-1-naphthyl]-1,10-phenanthroline (abbreviated as PnNPhen), and 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviated as pTpPPhen); 2-[3-(dibenzothiophene-4-yl)benzene 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h] Quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophene-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9pmDBtBP) Nfpr), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophene-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPB) fpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuran[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuran[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]furan[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthyl)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuran[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthyl)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuran[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm) Named as: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridin-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviated as: 2,6(P-Bqn)2Py), 2,2'-(pyridin-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviated as: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviated as: 6mBP-4Cz2PPm), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviated as: 2,4NP-6PyPPm), 4-[3,5-Bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 11-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furano[2,3-b]pyrazine (abbreviation: 11) Organic compounds with a diazine skeleton, such as mDBtBPPnfpr; 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobis[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H- Carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indo[2,1-b]carbazole (abbreviation: mI) Nc(II)PTzn), 2-{3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenyl-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]oxanthracene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)Tzn), 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3, 5-Triazine (abbreviation: mSiTrz), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)Tzn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9'-[6-(biphenyl-4-yl)-2-phenyl] Organic compounds including heteroaromatic rings with a triazine skeleton, such as [4-phenyl-1,3,5-triazine-4,3''-diyl]bis(9H-carbazole] (abbreviated as Cz-pmCzBPTzn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazine-2-yl]-9H-carbazole (abbreviated as PDBf-PCzTzn), and 9-[4-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzothiophene]-2-phenyl-9H-carbazole (abbreviated as PCzDBtTzn), are preferred. Furthermore, organic compounds containing heteroaromatic rings with a diazine skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing heteroaromatic rings with diazine (pyrimidine or pyrazine) skeletons and organic compounds containing heteroaromatic rings with triazine skeletons exhibit high electron transport properties, which helps to reduce the driving voltage.

[0282] When using a fluorescent luminescent material as the luminescent center, a material with an anthracene framework is preferably used as the host material. By using a material with an anthracene framework as the host material of the fluorescent luminescent material, a luminescent layer with both high luminous efficiency and durability can be achieved. Among the anthracene-based materials used as host materials, those with a diphenylanthracene framework, especially a 9,10-diphenylanthracene framework, are chemically stable and therefore preferred. Furthermore, when the host material has a carbazole framework, hole injection / transport is improved, which is also preferred. When the host material has a benzo[a]carbazole framework with a benzene ring fused to a carbazole, its HOMO energy level is about 0.1 eV higher than that of a material with a carbazole framework, facilitating hole injection, which is even more desirable. In particular, when the host material has a dibenzo[a]carbazole framework, its HOMO energy level is about 0.1 eV higher than that of a host material with a carbazole framework, not only facilitating hole injection but also improving hole transport and heat resistance, which is also preferred. Therefore, a further preferred material for use as the host material is one having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzo[a]carbazole skeleton or a dibenzo[a]carbazole skeleton). Note that from the viewpoint of hole injection / transportation described above, a benzo[a]fluorene skeleton or a dibenzo[a]fluorene skeleton can also be used instead of a carbazole skeleton. Examples of such substances include 9-[4-(9-phenylcarbazole-3-yl)]phenyl-10-phenylanthracene (abbreviated as PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as CzPA), 7-[4-(10-phenyl-9-anthrayl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthrayl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluorene-9-yl)biphenyl- 4'-yl]anthracene (abbreviated as: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviated as: α,βADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthrayl)benzo[b]naphtho[2,3-d]furan (abbreviated as: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviated as: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthrayl]phenyl}-2-ethyl-1H-benzimidazole (abbreviated as: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties and are therefore preferred.

[0283] Furthermore, the host material can also be a mixture of multiple substances. When using a mixed host material, it is preferable to mix materials with electron transport properties and materials with hole transport properties. By mixing materials with electron transport properties and materials with hole transport properties, it is easier to adjust the transport properties of the light-emitting layer 113 and to control the composite region more easily. The weight ratio of the materials with hole transport properties to those with electron transport properties can be from 1:19 to 19:1.

[0284] Note that phosphorescent materials can be used as part of the above-described mixture. When used as a fluorescent material, the phosphorescent material can act as an energy donor to supply excitation energy to the fluorescent material.

[0285] Furthermore, these mixed materials can also be used to form excimer complexes. By selecting a combination of excimer complexes that emit light with wavelengths overlapping the absorption band on the lowest energy side of the luminescent material, energy transfer can be facilitated, resulting in efficient luminescence, which is therefore preferred. Furthermore, this structure allows for a reduction in the driving voltage, making it also preferred.

[0286] Note that at least one of the materials forming the excitocomplex can be a phosphorescent material. This allows for the efficient conversion of triplet excitation energy into singlet excitation energy via antisystem crossing.

[0287] Regarding the combination of materials for efficiently forming excitocomplexes, the HOMO energy level of the material with hole transport is preferably above the HOMO energy level of the material with electron transport. Furthermore, the LUMO energy level of the material with hole transport is preferably above the LUMO energy level of the material with electron transport. Note that the LUMO and HOMO energy levels of the material can be determined from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0288] Note that the formation of excitocomplexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, the emission spectra of an electron-transporting material, and the emission spectra of a hybrid film formed by mixing these materials. When the emission spectrum of the hybrid film is observed to shift towards a longer wavelength (or to have a new peak on the longer wavelength side) compared to the emission spectra of each material, it indicates the formation of an excitocomplex. Alternatively, by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a hybrid film formed by mixing these materials, when a difference in transient response is observed, such as the mixed film having a longer lifetime component or a higher ratio of delayed components compared to the transient PL lifetimes of each material, it indicates the formation of an excitocomplex. Furthermore, the aforementioned transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a hybrid film of these materials, and observing the differences in transient responses, the formation of an excitocomplex can be confirmed.

[0289] The first electron transport layer 114_1 is a layer containing a material with electron transport properties. Preferably, the material with electron transport properties has an electron mobility of 1×10⁻⁶ when the square root of the electric field strength [V / cm] is 600. -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 Substances with a value of / Vs or higher. Note that substances other than those described above can be used as long as electron transport is higher than hole transport. As the above-described organic compounds, organic compounds comprising π-electron-deficient heteroaromatic rings are preferred. As organic compounds comprising π-electron-deficient heteroaromatic rings, for example, one or more of the following are preferred: organic compounds comprising a heteroaromatic ring with an azole skeleton, organic compounds comprising a heteroaromatic ring with a pyridine skeleton, organic compounds comprising a heteroaromatic ring with a diazine skeleton, and organic compounds comprising a heteroaromatic ring with a triazine skeleton; organic compounds comprising a heteroaromatic ring with a triazine skeleton are particularly preferred.

[0290] As an organic compound with electron transport properties that can be used in the first electron transport layer 114_1, similarly, organic compounds with electron transport properties that can be used as the host material in the first light-emitting layer 113_1 and the second light-emitting layer 113_2 can be used. Among these, organic compounds containing heteroaromatic rings with a diazine skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings with a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage.

[0291] In addition, the first electron transport layer 114_1 is equivalent to the electron transport layer in the light-emitting unit on the anode side.

[0292] The second electron transport layer 114_2 corresponds to the electron transport layer in the light-emitting unit on the cathode side described above. As mentioned above, the second electron transport layer 114_2 contains a sixth organic compound having a triazine skeleton. Its details have been described above and will not be repeated here.

[0293] Note that the first electron transport layer 114_1 preferably contains a seventh organic compound having a triazine skeleton, thereby reducing power consumption. Particularly preferred is that the seventh organic compound and the sixth organic compound with a triazine skeleton contained in the second electron transport layer 114_2 are organic compounds having the same triazine skeleton, which is beneficial for reducing the complexity of manufacturing equipment and also advantageous from the perspective of raw material procurement costs.

[0294] Furthermore, by including the first electron transport layer 114_1 in an 18th organic compound that does not have a triazine skeleton, the carrier transport properties can be easily controlled, thereby providing a light-emitting device with better characteristics. As the organic compound that does not have a triazine skeleton, organic compounds containing a heteroaromatic ring with a pyridine skeleton or organic compounds containing a heteroaromatic ring with a diazine (pyrimidine or pyrazine) skeleton are preferred.

[0295] The intermediate layer 116 contains a fifth organic compound with a phenanthrene skeleton. For example... Figure 1A As shown, the intermediate layer 116 preferably includes a first layer 119 comprising a fifth organic compound having a phenanthroline skeleton. Furthermore, the intermediate layer 116 preferably includes a second layer 117 comprising a 17th organic compound having hole-transporting properties and an acceptor substance. Moreover, the second layer 117 is closer to the second electrode 102 than the first layer 119. Additionally, the intermediate layer 116 may also include a third layer 118 between the first layer 119 and the second layer 117.

[0296] The details of the first layer have already been explained above and will not be repeated here.

[0297] Furthermore, the first layer 119 may also contain an organic compound with electron transport properties. As an organic compound with electron transport properties that can be used as such, an organic compound that can also be used as the host material in the first light-emitting layer 113_1 and the second light-emitting layer 113_2 can also be used. Moreover, as such an organic compound, it is preferable to use an organic compound having two or more heteroaromatic rings bonded or fused together, and the two or more heteroaromatic rings containing a total of three or more heteroatoms, thereby further improving resistance to photolithography and suppressing the rise of the driving voltage.

[0298] Note that the first layer 119 can be a stacked structure of a layer containing an organic compound and a layer containing a metal or metal compound located closer to the cathode than the layer containing the organic compound. It can also be a mixed layer of organic compound and metal or metal compound. When the first layer is a mixed layer, fewer deposition chambers are required, manufacturing costs are reduced, and the stability of the light-emitting device is improved, so it is preferred.

[0299] In the case of a mixture of organic compounds and metals or metal compounds, when analyzing the first layer 119 in the thickness direction, the distribution of organic compounds and the distribution of metals or metal compounds show approximately the same trend. That is, when the distribution of organic compounds is fixed, the distribution of metals or metal compounds is also approximately fixed. In the stacked structure of organic compounds and layers containing metals or metal compounds, sometimes metals or metal compounds are detected in areas outside the layers containing metals or metal compounds due to diffusion from those layers. However, because they exhibit a different distribution than that of organic compounds, the analytical results of diffusion and mixing can be distinguished.

[0300] The second layer 117 preferably comprises a 17th organic compound having hole-transporting properties. Furthermore, the second layer 117 preferably also comprises a receptor-presenting substance, which is preferably an organic compound that is receptor-presenting to the 17th organic compound.

[0301] When the second layer 117 contains the 17th organic compound and a substance that is acceptor of the 17th organic compound, holes are generated through charge separation. When a voltage is applied between the first electrode 101 and the second electrode 102, these holes are injected into the second light-emitting unit 502 on the cathode side through the 17th organic compound. Thus, the light-emitting device 130 of one embodiment of the present invention can be a light-emitting device with a low driving voltage.

[0302] As the 17th organic compound with hole transport capability, various organic compounds such as aromatic amines, heteroaromatic compounds, aromatic hydrocarbons, and polymers (oligomers, dendritic polymers, polymers, etc.) can be used. As the fifth organic compound, a hole mobility of 1×10⁻⁶ is preferred. -6 cm 2 Organic compounds with a ratio of / Vs or higher. Furthermore, the fifth organic compound is preferably a compound containing a fused aromatic ring or a π-electron-rich heteroaromatic ring. As a fused aromatic ring, anthracene rings, naphthalene rings, etc., are preferred. Furthermore, as a π-electron-rich heteroaromatic ring, a fused aromatic ring having at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton is preferred; specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are also fused with an aromatic ring or heteroaromatic ring.

[0303] Such hole-transporting organic compounds are more preferably those having a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, they can be aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines including a naphthyl ring, or aromatic monoamines in which a 9-fluorene group is bonded to the nitrogen of the amine via an arylene group. Note that when these hole-transporting organic compounds are substances including N,N-bis(4-biphenyl)amino groups, long-lifetime light-emitting devices can be manufactured, and therefore they are preferred.

[0304] Specifically, as the aforementioned hole-transporting organic compound, the organic compound mentioned above that is a hole-transporting organic compound that can be used in the hole injection layer 111 can also be used.

[0305] As a receptor-like substance, for example, an organic compound that can be used in the hole injection layer 111 can be used. In particular, an organic compound having at least one of a halogen group and a cyano group is preferred, and an organic compound having at least one of a fluorine group and a cyano group is more preferred. Furthermore, the total number of halogen (fluorine) and cyano groups contained in the organic compound is more preferably four or more. Examples of organic compounds having at least one of a halogen group and a cyano group include: α,α',α''-1,2,3-cyclopropanetrimethylenetri[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,3,4,5,6-pentafluorophenylacetonitrile], etc.

[0306] Furthermore, the acceptor material preferably has electron acceptor properties for the 17th organic compound, which has hole transport properties. When the acceptor material has electron acceptor properties for the 17th organic compound, charge separation occurs, and the second layer 117 can be used as a charge generation layer and as an intermediate layer in a tandem light-emitting device. Furthermore, in the second layer 117, a signal observed via electron spin resonance is preferably detected. For example, the spin density arising from a signal observed near a g value of 2.00 is preferably 1 × 10⁻⁶. 17 spins / cm 3 The above is preferred to be 1×10 18 spins / cm 3 The above is further preferred to be 1×10 19 spins / cm 3 above.

[0307] The third layer 118 contains an electron transport material and has the functions of preventing the interaction between the first layer 119 and the second layer 117, facilitating electron transfer to reduce the driving voltage, and reducing the interaction between the first layer 119 and the second layer 117 to improve reliability.

[0308] The LUMO energy level of the electron transport material contained in the third layer 118 is preferably the LUMO energy level of the acceptor material in the second layer 117 and the layer in the light-emitting unit on the anode side that is in contact with the first layer 119. Figure 1A Between the LUMO energy levels of the organic compounds contained in the first electron transport layer 114_1 in the first light-emitting unit 501.

[0309] Specifically, the LUMO energy level of the electron transport material used in the third layer 118 is -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower, more preferably -4.30 eV or higher and -3.00 eV or lower, and even more preferably -4.30 eV or higher and -3.30 eV or lower. This suppresses the rise in the driving voltage of the light-emitting device, and is therefore preferred. Furthermore, phthalocyanine materials or metal complexes having metal-oxygen bonds and aromatic ligands are preferably used as the electron transport material in the third layer 118.

[0310] As electron-transporting substances for the third layer 118, specifically, perylene tetracarboxylic acid derivatives such as diquinoxolino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,3,8,9,14,15-hexafluorodiquinoxolino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA-F6), 3,4,9,10-perylene tetracarboxylic acid diimide (abbreviated as PTCDI), and 3,4,9,10-perylene tetracarboxylic acid-bis-benzimidazole (abbreviated as PTCBI), as well as (C60-Ih)[5,6]fullerene (abbreviated as C60) and (C70-D5h)[5,6]fullerene (abbreviated as C70) can be used. Furthermore, compounds having a heterocyclic cyclophenene skeleton can be used; for example, phthalocyanine compounds such as phthalocyanine (abbreviated as H2Pc) can be used. In addition, metal phthalocyanines containing copper, zinc, cobalt, chromium, nickel, etc., and their derivatives, such as copper phthalocyanine (CuPc), zinc phthalocyanine (ZnPc), cobalt phthalocyanine (CoPc), iron phthalocyanine (FePc), tin phthalocyanine (SnPc), tin oxide phthalocyanine (SnOPc), titanium oxide phthalocyanine (TiOPc), and vanadium oxide phthalocyanine (VOPc), can be used. In particular, phthalocyanine metal complexes such as copper phthalocyanine or zinc phthalocyanine, or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine, are preferred.

[0311] Furthermore, the thickness of the third layer 118 is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 5 nm or less.

[0312] Furthermore, since the second layer 117 in the intermediate layer 116 is used as a hole injection layer, the second light-emitting unit 502 does not have a hole injection layer, but the second light-emitting unit 502 may also have a hole injection layer.

[0313] The second electrode 102 is an electrode that includes a cathode. The second electrode 102 can also employ a stacked structure, in which case the layer in contact with the organic compound layer 103 serves as the cathode. As the material forming the cathode, metals, alloys, conductive compounds, and mixtures thereof with low work functions (specifically below 3.8 eV) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), alloys containing them (MgAg, AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing them. Specifically, examples include alkali metals, alkaline earth metals, rare earth metals, compounds or complexes thereof, or electronic compounds such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-hydroxyquinoline-lithium (Liq), and ytterbium (Yb). Examples of electronic compounds include mixed oxides of calcium and aluminum that add electrons at high concentrations. Furthermore, two or more of the aforementioned materials can be mixed and used. When the second electrode 102 employs a multilayer structure, materials with good conductivity can be used for the portion other than the cathode without considering the work function.

[0314] Note that the second electron transport layer 114_2 is preferably in contact with the second electrode 102. By making the second electron transport layer 114_2 in contact with the second electrode 102, a light-emitting device with good electron injection and electron transport properties, low driving voltage, and low power consumption can be obtained.

[0315] When the second electrode 102 is made of a material that is transparent to visible light, a light-emitting device that emits light from one side of the second electrode 102 can be formed.

[0316] These conductive materials can be formed using dry methods such as vacuum evaporation and sputtering, as well as inkjet printing and spin coating. Alternatively, they can be formed using wet methods such as sol-gel or wet methods using pastes of metallic materials.

[0317] Furthermore, various methods, whether dry or wet, can be used to form the organic compound layer 103. For example, vacuum evaporation, gravure printing, offset printing, screen printing, inkjet printing, or spin coating can also be used.

[0318] In addition, the electrodes or layers described above can also be formed by using different deposition methods.

[0319] Figure 1CThis diagram illustrates two adjacent light-emitting devices (light-emitting device 130a and light-emitting device 130b) included in a display device according to one embodiment of the present invention. Light-emitting device 130a is a light-emitting device according to one embodiment of the present invention having the same structure as light-emitting device 130.

[0320] The light-emitting device 130a includes an organic compound layer 103a between the first electrode 101a and the second electrode 102 on the insulating layer 175. The organic compound layer 103a has a structure in which a first light-emitting unit 501a and a second light-emitting unit 502a are stacked, with an intermediate layer 116a sandwiched between them. Note that although... Figure 1C An example of two stacked light-emitting units is shown, but three or more light-emitting units can also be stacked. The first light-emitting unit 501a includes a hole injection layer 111a, a first hole transport layer 112a_1, a first light-emitting layer 113a_1, and a first electron transport layer 114a_1. The intermediate layer 116a includes a second layer 117a, a third layer 118a, and a first layer 119a. Furthermore, the third layer 118a may or may not be included. The second light-emitting unit 502a includes a second hole transport layer 112a_2, a second light-emitting layer 113a_2, and a second electron transport layer 114a_2.

[0321] The light-emitting device 130b includes an organic compound layer 103b between the first electrode 101b and the second electrode 102 on the insulating layer 175. The organic compound layer 103b has a structure in which a first light-emitting unit 501b and a second light-emitting unit 502b are stacked, with an intermediate layer 116b sandwiched between them. Note that although... Figure 1C An example of two stacked light-emitting units is shown, but more than three light-emitting units can also be stacked. The first light-emitting unit 501b includes a hole injection layer 111b, a first hole transport layer 112b_1, a first light-emitting layer 113b_1, and a first electron transport layer 114b_1. The intermediate layer 116b includes a second layer 117b, a third layer 118b, and a first layer 119b. Furthermore, the third layer 118b may or may not be included. The second light-emitting unit 502b includes a second hole transport layer 112b_2, a second light-emitting layer 113b_2, and a second electron transport layer 114b_2.

[0322] The second electron transport layers 114a_2 and 114b_2 are preferably layers containing a sixth organic compound having a triazine skeleton. The first layers 119a and 119b are preferably layers containing a fifth organic compound having a phenanthroline skeleton.

[0323] The first luminescent layer 113a_1 and the second luminescent layer 113a_2 are preferably luminescent layers exhibiting similar colors. Furthermore, the luminescent center material they contain is preferably a compound whose maximum peak wavelength difference in its emission spectrum is 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less. More preferably, they contain the same luminescent center material. The first luminescent layer 113b_1 and the second luminescent layer 113b_2 are preferably luminescent layers exhibiting similar colors. Furthermore, the luminescent center material they contain is preferably a compound whose maximum peak wavelength difference in its emission spectrum is 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less. More preferably, they contain the same luminescent center material. Furthermore, the first luminescent layer 113a_1 and the second luminescent layer 113a_2 are preferably constructed from the same material. One of the first luminescent layer 113a_1 and the second luminescent layer 113a_2, preferably both of them, preferably have the structure of a luminescent layer according to one aspect of the present invention described above.

[0324] Furthermore, preferably, the first light-emitting layer 113a_1 and the first light-emitting layer 113b_1 are separate, and the second light-emitting layer 113a_2 and the second light-emitting layer 113b_2 are separate. Furthermore, the emission color of the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 is preferably different from the emission color of the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2. Furthermore, preferably, the fluorescent luminescent material contained in the first light-emitting layer 113a_1 is different from the luminescent center material contained in the first light-emitting layer 113b_1, and the fluorescent luminescent material contained in the second light-emitting layer 113a_2 is different from the luminescent center material contained in the second light-emitting layer 113b_2. Furthermore, the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are preferably made of the same material.

[0325] Furthermore, the hole injection layers 111a and 111b, the first hole transport layers 112a_1 and 112b_1, the first electron transport layers 114a_1 and 114b_1, the intermediate layers 116a and 116b (the second layers 117a and 117b, the third layers 118a and 118b, and the first layers 119a and 119b), the second hole transport layers 112a_2 and 112b_2, and the second electron transport layers 114a_2 and 114b_2 can each be continuous layers or separated between the light-emitting devices 130a and 130b. By using continuous layers, productivity is improved, allowing the manufacture of inexpensive light-emitting devices. By using layers separated between the light-emitting devices, materials suitable for the emitted color can be used, enabling the manufacture of light-emitting devices or display devices with excellent characteristics. In particular, by using continuous layers as the second electron transport layer 114a_2 and the second electron transport layer 114b_2, both the light-emitting device 130a and the light-emitting device 130b can become light-emitting devices with good characteristics, which is preferred.

[0326] The continuous layers mean that the second electron transport layer 114a_2 and the second electron transport layer 114b_2 are made of the same material. That is, by using the same material to construct the second electron transport layer 114a_2 and the second electron transport layer 114b_2, both the light-emitting device 130a and the light-emitting device 130b can become light-emitting devices with good characteristics. Furthermore, it is more preferable that the second electron transport layer 114a_2 and the second electron transport layer 114b_2 have the same structure, and even more preferably, they have the same structure.

[0327] Furthermore, when the fluorescent luminescent material contained in the first luminescent layer 113a_1 is different from the luminescent center material contained in the first luminescent layer 113b_1, and the fluorescent luminescent material contained in the second luminescent layer 113a_2 is different from the luminescent center material contained in the second luminescent layer 113b_2 (for example, in the following cases: the first luminescent layer 113a_1 and the second luminescent layer 113a_2 are blue fluorescent luminescent layers, and the first luminescent layer 113b_1 and the second luminescent layer 113b_2 are green fluorescent luminescent layers). The phosphorescent emitting layers are: first emitting layer 113a_1 and second emitting layer 113a_2 are blue phosphorescent emitting layers, and first emitting layer 113b_1 and second emitting layer 113b_2 are red phosphorescent emitting layers; or first emitting layer 113a_1 and second emitting layer 113a_2 are green phosphorescent emitting layers, and first emitting layer 113b_1 and second emitting layer 113b_2 are red phosphorescent emitting layers. The carrier balance of the emitting layers in light-emitting devices 130a and 130b is different. Therefore, in many cases, in order to enable light-emitting devices 130a and 130b to perform their respective functions, it is necessary to select and use appropriate intermediate layers and electron transport layers respectively. However, by using a layer containing a sixth organic compound with a triazine skeleton as the second electron transport layer 114a_2 and the second electron transport layer 114b_2, and using a layer containing a fifth organic compound with a phenanthroline skeleton as the first layer 119a and the first layer 119b, both the second electron transport layer 114a_2 and the second electron transport layer 114b_2 can perform their functions even if they have the same structure. In other words, both productivity and performance can be improved simultaneously. Furthermore, the first layer 119a and the first layer 119b can also have the same structure.

[0328] Note that the continuous layer refers to the so-called common layer formed across both light-emitting devices 130a and 130b.

[0329] Figure 2A yes Figure 1CExamples of variations are provided. Since the light-emitting devices 130a and 130b emit different colors, the optical path lengths between the electrodes that amplify the light emission via a microcavity are different. Therefore, in light-emitting device 130b1, the distance between the electrodes can be adjusted by increasing the thickness of the light-emitting layer, as in light-emitting layers 113b_11 and 113b_21. Alternatively, the optical path length can be changed by increasing the thickness of the functional layer or by adding a functional layer, as in hole transport layer 112b_21. Furthermore, an example is shown where the emission peak wavelength of light-emitting device 130a is shorter than that of light-emitting device 130b. Both light-emitting devices 130a and 130b can have the same structure as light-emitting device 130 described above, but only light-emitting device 130a may have the structure of the light-emitting device according to the above-described embodiment of the present invention. In the case where only light-emitting device 130a has the structure of the light-emitting device according to the above-described embodiment of the present invention, the light-emitting center material contained in the light-emitting layer of light-emitting device 130b is preferably a phosphorescent material.

[0330] Figure 2B The diagram shows three adjacent light-emitting devices (light-emitting device 130a, light-emitting device 130b1, and light-emitting device 130c) included in a display device according to one aspect of the present invention.

[0331] The light-emitting device 130c includes an organic compound layer 103c between the first electrode 101c and the second electrode 102 on the insulating layer 175. The organic compound layer 103c has a structure in which the first light-emitting unit 501c and the second light-emitting unit 502c are stacked separated by an intermediate layer 116c. Note that although... Figure 2B An example of two stacked light-emitting units is shown, but three or more light-emitting units can also be stacked. The first light-emitting unit 501c includes a hole injection layer 111c, a first hole transport layer 112c_1, a first light-emitting layer 113c_1, and a first electron transport layer 114c_1. The intermediate layer 116c includes a second layer 117c, a third layer 118c, and a first layer 119c. Furthermore, the third layer 118c may or may not be included. The second light-emitting unit 502c includes second hole transport layers 112c_2 and 112c_2, a second light-emitting layer 113c_2, and a second electron transport layer 114c_2.

[0332] The wavelength of the emitted color of light-emitting device 130c is assumed to be longer than that of light-emitting devices 130a and 130b1. As the electrode spacing of light-emitting device 130c, the thicknesses of light-emitting layers 113c_1 and 113c_2 are made thicker than the light-emitting layers of the other two light-emitting devices, and the electrode spacing of the light-emitting devices is adjusted by the second hole transport layer 112c_21. Note that the luminescent center material contained in the first light-emitting layer 113c_1 and the second light-emitting layer 113c_2 is preferably a phosphorescent material.

[0333] The second electron transport layer 114c_2 is preferably a layer containing a sixth organic compound having a triazine skeleton. The first layer 119c is preferably a layer containing a fifth organic compound having a phenanthroline skeleton.

[0334] The first luminescent layer 113c_1 and the second luminescent layer 113c_2 are preferably luminescent layers that emit light in similar colors. Furthermore, the luminescent center materials they contain are preferably compounds whose maximum peak wavelength difference in emission spectrum is less than 30 nm, more preferably less than 20 nm, and even more preferably less than 10 nm. More preferably, they contain the same luminescent center material. Additionally, the first luminescent layer 113c_1 and the second luminescent layer 113c_2 are preferably made of the same material.

[0335] Furthermore, preferably, the first light-emitting layer 113a_1 is separate from the first light-emitting layer 113c_1, and the second light-emitting layer 113a_2 is separate from the second light-emitting layer 113c_2. Furthermore, the emission colors of the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are preferably different from the emission colors of the first light-emitting layer 113c_1 and the second light-emitting layer 113c_2. Furthermore, preferably, the fluorescent luminescent material contained in the first light-emitting layer 113a_1 is different from the luminescent center material contained in the first light-emitting layer 113c_1, and the fluorescent luminescent material contained in the second light-emitting layer 113a_2 is different from the luminescent center material contained in the second light-emitting layer 113c_2.

[0336] Notice, Figure 2B The following example illustrates this: hole injection layers 111a and 111b, first hole transport layers 112a_1 and 112b_1, first electron transport layers 114a_1 and 114b_1, intermediate layers 116a and 116b (second layers 117a and 117b, third layers 118a and 118b, first layers 119a and 119b), and second hole transport layers 112a_2 and 112b_2 are independent layers between light-emitting devices 130a and 130b, while second electron transport layers 114a_2 to 114c_2 are continuous layers. Thus, a light-emitting device can include both continuous and separate layers. This allows for the manufacture of light-emitting devices or display devices that achieve a balance between productivity and performance. In particular, the second electron transport layer 114a_2 to the second electron transport layer 114c_2 are preferably continuous layers, thereby enabling both the light-emitting device 130a and the light-emitting device 130b to become light-emitting devices with good characteristics.

[0337] For example, in the case where two of the three-color light-emitting devices contain fluorescent light-emitting centers and one contains phosphorescent light-emitting centers, it is preferable that the carrier transport layer is formed as a continuous layer in the light-emitting device containing the fluorescent light-emitting center, and that the carrier transport layer is formed as a separate layer from the light-emitting devices emitting other colors in the light-emitting device containing the phosphorescent light-emitting center. Alternatively, in the case where two of the three-color light-emitting devices contain phosphorescent light-emitting centers and one contains fluorescent light-emitting centers, it is preferable that the carrier transport layer is formed as a continuous layer in the light-emitting device containing the phosphorescent light-emitting center, and that the carrier transport layer is formed as a separate layer from the light-emitting devices emitting other colors in the light-emitting device containing the fluorescent light-emitting center.

[0338] In a display device with three colors of light emission, when one light emission device is a fluorescent light emission device and the remaining two are phosphorescent light emission devices, the fluorescent light emission device preferably includes a light emission layer comprising the aforementioned fluorescent light emission material, a first host material, and a second host material, wherein both the first host material and the second host material are organic compounds and both contain polycyclic hydrocarbons. In this case, the remaining phosphorescent light emission devices also preferably comprise two host materials. That is, the light emission layer of the light emission device included in one aspect of the present invention preferably comprises multiple host materials.

[0339] The light-emitting device of the present invention having this structure can be a light-emitting device with high current efficiency, low energy loss, and good characteristics. A display device using this light-emitting device, according to one embodiment of the present invention, can be a display device with low power consumption, high reliability, and good visibility, capable of displaying at high brightness. Furthermore, this embodiment can be freely combined with other embodiments.

[0340] (Implementation Method 2) In this embodiment, a display device manufactured using the light-emitting device shown in Embodiment 1 will be described with reference to FIG3. Note that... Figure 3A This is a top view showing the display device, and Figure 3B It is along Figure 3A The diagram shows a cross-sectional view of lines AB and CD cut off. The display device, as a unit for controlling the light emission of the light-emitting device, includes a driving circuit section (source line driving circuit) 601 (indicated by dashed lines), a pixel section 602, and a driving circuit section (gate line driving circuit) 603. Furthermore, symbol 604 represents a sealing substrate, symbol 605 represents a sealing material, and the inner side surrounded by the sealing material 605 is a space 607.

[0341] Note that the guide wiring 608 is used to transmit signals input to the source line drive circuit 601 and the gate line drive circuit 603, and to receive video signals, clock signals, start signals, reset signals, etc., from the FPC (flexible printed circuit) 609, which serves as an external input terminal. Note that although only the FPC is shown here, it can also be equipped with a printed circuit board (PWB). The display device described in this specification includes not only the display device body but also the display device equipped with an FPC or PWB.

[0342] Below, refer to Figure 3B Explanation of the cross-sectional structure. Although a driving circuit section and a pixel section are formed on the element substrate 610, only one pixel of the source line driving circuit 601 and pixel section 602 is shown here.

[0343] In addition to substrates made of glass, quartz, organic resin, metal, alloy, semiconductor, etc., the component substrate 610 can also use plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester or acrylic resin.

[0344] There are no particular restrictions on the structure of the transistors used in the pixel and driving circuitry. For example, anti-interleaved transistors or interleaved transistors can be used. Alternatively, top-gate transistors or bottom-gate transistors can also be used. There are no particular restrictions on the semiconductor materials used in the transistors; for example, silicon, germanium, silicon carbide, gallium nitride, etc., can be used. Alternatively, oxide semiconductors containing at least one of indium, gallium, and zinc, such as In-Ga-Zn metal oxides, can also be used.

[0345] There are no particular restrictions on the crystallinity of the semiconductor material used in transistors; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors in which a portion has crystalline regions) can be used. Crystalline semiconductors are preferred because they can suppress transistor performance degradation.

[0346] Here, oxide semiconductors are preferably used in semiconductor devices such as transistors disposed in the aforementioned pixels and driving circuits, and in transistors for touch sensors, etc., which will be described later. Oxide semiconductors with a wider bandgap than silicon are particularly preferred. By using oxide semiconductors with a wider bandgap than silicon, the off-state current of the transistors can be reduced.

[0347] The aforementioned oxide semiconductor preferably contains at least indium (In) or zinc (Zn). Furthermore, the aforementioned oxide semiconductor is more preferably an oxide semiconductor containing oxides represented by In-M-Zn type oxides (M being metals such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0348] In particular, as a semiconductor layer, an oxide semiconductor film is preferably used that has a plurality of crystal portions in which the c-axis is oriented in a direction perpendicular to the surface of the semiconductor layer or the top surface of the semiconductor layer, and there are no grain boundaries between adjacent crystal portions.

[0349] By using the aforementioned materials as a semiconductor layer, variations in electrical properties are suppressed, enabling the realization of highly reliable transistors.

[0350] Furthermore, because the transistors with the aforementioned semiconductor layer have low off-state currents, the charge stored in the capacitors through the transistors can be maintained for extended periods. By using such transistors in pixels, the driving circuit can be stopped while maintaining the grayscale of the image displayed in each display area. As a result, electronic devices with extremely low power consumption can be realized.

[0351] To stabilize transistor characteristics, a base film is preferably provided. As the base film, inorganic insulating films such as silicon oxide, silicon nitride, silicon oxynitride, and silicon oxynitride can be used and fabricated as a single layer or in stacks. The base film can be formed by sputtering, CVD (Chemical Vapor Deposition) methods (plasma CVD, thermal CVD, MOCVD (Metal Organic CVD), etc.), ALD (Atomic Layer Deposition), coating, printing, etc. Note that a base film is optional if not required.

[0352] Note that FET623 represents one of the transistors formed in the drive circuit section 601. Furthermore, the drive circuit can also be formed using various CMOS, PMOS, or NMOS circuits. Although this embodiment shows an integrated driver type with the drive circuit formed on the substrate, this structure is not mandatory; the drive circuit can also be formed externally instead of on the substrate.

[0353] Furthermore, the pixel unit 602 is formed by a plurality of pixels, each of which includes a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain of the current control FET 612. However, it is not limited to this and a pixel unit combining three or more FETs and capacitors may also be used.

[0354] Note that the insulator 614 is formed in such a way that it covers the end of the first electrode 613. Here, a positive photosensitive acrylic resin film can be used to form the insulator 614.

[0355] Furthermore, the upper or lower end of the insulator 614 is formed into a curved surface to obtain good coverage for the organic compound layer or the like formed later. For example, when using a positive photosensitive acrylic resin as the material of the insulator 614, it is preferable that only the upper end of the insulator 614 includes a curved surface with a radius of curvature (0.2 μm to 3 μm). Negative or positive photosensitive resins can be used as the insulator 614.

[0356] An organic compound layer 616 and a second electrode 617 are formed on the first electrode 613. Here, a material with a high work function is preferably used as the material for the first electrode 613, which serves as the anode. For example, in addition to single-layer films such as ITO films, indium tin oxide films containing silicon, indium oxide films containing 2 wt% to 20 wt% zinc oxide, titanium nitride films, chromium films, tungsten films, Zn films, and Pt films, a stacked structure composed of a titanium nitride film and a film mainly composed of aluminum, and a three-layer structure composed of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film, can also be used. Note that when a stacked structure is used, the resistance of the wiring can be lower, good ohmic contact can be obtained, and it can be used as the anode.

[0357] Furthermore, the organic compound layer 616 is formed using various methods such as vapor deposition using a vapor deposition mask, inkjet printing, spin coating, etc. The organic compound layer 616 includes the structure shown in Embodiment 1. In addition, low-molecular-weight compounds or high-molecular-weight compounds (including oligomers and dendritic polymers) may be used as other materials constituting the organic compound layer 616.

[0358] Furthermore, as the material used for the second electrode 617 formed on the organic compound layer 616 and used as a cathode, a material with a low work function (Al, Mg, Li, Ca, or their alloys and compounds (MgAg, MgIn, AlLi, etc.)) is preferably used. Note that when light generated in the organic compound layer 616 is transmitted through the second electrode 617, a stack consisting of a thinned metal film and a transparent conductive film (ITO, indium oxide containing 2wt% to 20wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) is preferably used as the second electrode 617.

[0359] Furthermore, the light-emitting device is formed from a first electrode 613, an organic compound layer 616, and a second electrode 617. This light-emitting device is the same as that shown in Embodiment 1. Additionally, since the pixel portion is formed from multiple light-emitting devices, the display device of this embodiment may also include both the light-emitting device shown in Embodiment 1 and light-emitting devices with other structures.

[0360] Furthermore, by attaching the sealing substrate 604 to the element substrate 610 using a sealing material 605, the light-emitting device 618 is disposed within a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. Note that the space 607 is filled with a filler; this filler can be an inactive gas (nitrogen, argon, etc.) or a sealing material. Forming a recess in the sealing substrate and placing a desiccant therein is preferred as it helps to suppress deterioration caused by moisture.

[0361] Furthermore, epoxy resin and glass powder are preferably used as sealing materials 605. These materials are also preferably those that minimize the permeability of moisture and oxygen. In addition to glass substrates and quartz substrates, plastic substrates made of FRP (fiber reinforced plastics), PVF (polyvinyl fluoride), polyester, or acrylic resin can also be used as the material for the sealing substrate 604.

[0362] Although not shown in Figure 3, a protective film can also be provided on the second electrode. The protective film can be formed from an organic resin film or an inorganic insulating film. Alternatively, the protective film can be formed to cover the exposed portion of the sealing material 605. Furthermore, the protective film can be provided to cover the surface and side surfaces of a pair of substrates, the exposed sides of the sealing layer, the insulating layer, etc.

[0363] As a protective membrane, materials that are not easily permeable to water and other impurities can be used. Therefore, it can effectively prevent water and other impurities from diffusing from the outside to the inside.

[0364] Materials that form the protective film can include oxides, nitrides, fluorides, sulfides, ternary compounds, metals, or polymers. For example, materials containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, or indium oxide can be used. Materials containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride can also be used. Materials containing titanium and aluminum nitrides, oxides containing titanium and aluminum, oxides containing aluminum and zinc, sulfides containing manganese and zinc, sulfides containing cerium and strontium, oxides containing erbium and aluminum, and oxides containing yttrium and zirconium can also be used.

[0365] The protective film is preferably formed using a deposition method with good step coverage. One such method is atomic layer deposition (ALD). Materials that can be formed using ALD are preferably used for the protective film. ALD can form a dense protective film with reduced or uniform thickness, minimizing defects such as cracks and pinholes. Furthermore, it can reduce damage to the machined component during the formation of the protective film.

[0366] For example, by forming a protective film using the ALD method, a uniform protective film with few defects can be formed on the top, sides, and back of a surface or touch panel with a complex uneven shape.

[0367] As described above, a display device manufactured using the light-emitting device shown in Embodiment 1 can be obtained.

[0368] Because the display device in this embodiment uses the light-emitting device shown in Embodiment 1, a display device with excellent characteristics can be obtained. Specifically, the light-emitting device shown in Embodiment 1 has high luminous efficiency, thereby enabling a low-power display device. Furthermore, the light-emitting device shown in Embodiment 1 has high reliability, thereby enabling a highly reliable display device. In addition, the light-emitting device shown in Embodiment 1 can have good chromaticity and high color purity, thereby enabling a display device with good display quality.

[0369] Furthermore, this embodiment can be freely combined with other embodiments.

[0370] (Implementation Method 3) like Figure 4A and Figure 4B As shown, a plurality of light-emitting devices 130 are formed on an insulating layer 175 and constitute a display device. In this embodiment, a display device according to another aspect of the present invention is described in detail.

[0371] The display device 100 includes a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixels 178 include sub-pixels 110R, 110G, and 110B.

[0372] In this specification, etc., the term "subpixel 110" is sometimes used to describe the common features among subpixels 110R, 110G, and 110B. Furthermore, regarding other constituent elements distinguished by letters, reference numerals with omitted letters are sometimes used to describe the common features among these constituent elements.

[0373] Subpixel 110R emits red light, subpixel 110G emits green light, and subpixel 110B emits blue light. Thus, an image can be displayed on pixel unit 177. Note that in this embodiment, only three colors of subpixels—red (R), green (G), and blue (B)—are used as examples for explanation; other colors of subpixels can also be combined. Furthermore, the number of subpixels is not limited to three; four or more can be used. Examples of four subpixels include: subpixels of four colors—R, G, B, and white (W); subpixels of four colors—R, G, B, and Y; and subpixels of four colors—R, G, B, and infrared (IR); etc.

[0374] In this specification, the row direction is sometimes referred to as the X direction and the column direction as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0375] exist Figure 4A In the example shown, subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction. Note that it is also possible to arrange subpixels of different colors in the Y direction and subpixels of the same color in the X direction.

[0376] A connecting portion 140 may be provided on the outer side of the pixel portion 177, and a region 141 may also be provided. When the region 141 is provided, it is located between the pixel portion 177 and the connecting portion 140. An organic compound layer is provided in the region 141. Additionally, a conductive layer 151C is provided on the connecting portion 140.

[0377] In the example shown in Figure 4, region 141 and connecting portion 140 are located to the right of pixel portion 177, but there are no particular restrictions on the position of region 141 and connecting portion 140. Furthermore, region 141 and connecting portion 140 may be one or more.

[0378] Figure 4B It is along Figure 4A An example of a cross-sectional view of the dashed-dot line A1-A2 in the diagram. For example... Figure 4B As shown, the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is disposed on a substrate (not shown). The insulating layers 175, 174, and 173 are provided with openings leading to the conductive layer 172, and a plug 176 is disposed such that it is inserted into the openings.

[0379] In the pixel section 177, a light-emitting device 130 is disposed on the insulating layer 175 and the plug 176. A protective layer 131 is disposed to cover the light-emitting device 130. The substrate 120 is attached to the protective layer 131 by a resin layer 122. In addition, it is preferable to provide an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 between adjacent light-emitting devices 130.

[0380] Figure 4B The cross-sections of the plurality of inorganic insulating layers 125 and the plurality of insulating layers 127 are shown, but when viewed from above the display device 100, the inorganic insulating layers 125 and the insulating layers 127 are preferably formed as a connected layer.

[0381] exist Figure 4B Light-emitting devices 130R, 130G, and 130B are shown as light-emitting devices 130. Light-emitting devices 130R, 130G, and 130B emit light of different colors from each other. For example, light-emitting device 130R may emit red light, light-emitting device 130G may emit green light, and light-emitting device 130B may emit blue light. Alternatively, light-emitting devices 130R, 130G, or 130B may also emit other visible or infrared light.

[0382] One aspect of the display device of the present invention may have a top emission structure that emits light in a direction opposite to that of the substrate on which the light-emitting device is formed. Alternatively, another aspect of the display device of the present invention may have a bottom emission structure.

[0383] The light-emitting device 130R includes a first electrode 101R (pixel electrode) composed of conductive layers 151R and 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103R during processing, making it a preferred option.

[0384] The light-emitting device 130G includes a first electrode 101G (pixel electrode) composed of conductive layers 151G and 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103G during processing, making it a preferred option.

[0385] The light-emitting device 130B has the structure shown in Embodiment 1. It comprises a first electrode 101B (pixel electrode) consisting of conductive layers 151B and 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103B during processing, making it preferred. Furthermore, when the common layer 104 is provided, the stacked structure of the organic compound layer 103B and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 1; when the common layer 104 is not provided, the organic compound layer 103B corresponds to the organic compound layer 103 in Embodiment 1.

[0386] Furthermore, the common layer 104 is preferably an electron transport layer. In addition, when the common layer 104 is an electron transport layer, the electron transport layer preferably adopts a stacked structure, and more preferably, the layer on the second electrode side of the stacked layers is the common layer 104 and the layer on the light-emitting layer side is an organic compound layer 103.

[0387] In addition, light-emitting devices 130R and 130G are also light-emitting devices manufactured through photolithography.

[0388] In the light-emitting device 130, one of the pixel electrode and the common electrode is used as an anode, and the other is used as a cathode. Hereinafter, unless otherwise specified, the description will assume that the pixel electrode is used as the anode and the common electrode is used as the cathode.

[0389] Organic compound layers 103R, 103G, and 103B are arranged independently in an island-like configuration for each light-emitting device or each light-emitting color. By arranging the organic compound layers 103 in an island-like configuration for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed in high-definition display devices. This suppresses crosstalk, enabling the realization of display devices with extremely high contrast. In particular, it enables display devices with high current efficiency at low brightness levels.

[0390] The island-shaped organic compound layer 103 is formed by depositing an organic compound film and processing the organic compound film using photolithography.

[0391] The organic compound layer 103 is preferably disposed such that it covers the top and side surfaces of the first electrode (pixel electrode) of the light-emitting device 130. This makes it easier to increase the aperture ratio of the display device 100 compared to a structure where the end of the organic compound layer 103 is located inside the end of the pixel electrode. Furthermore, by covering the side surfaces of the pixel electrode of the light-emitting device 130 with the organic compound layer 103, contact between the pixel electrode and the second electrode 102 can be suppressed, thus preventing short circuits in the light-emitting device 130.

[0392] Furthermore, in one embodiment of the display device of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably employs a stacked structure. For example, in Figure 4B In the example shown, the first electrode of the light-emitting device 130 adopts a stacked structure of conductive layer 151 and conductive layer 152.

[0393] As the conductive layer 151, a metallic material can be used, for example. Specifically, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys thereof can also be used.

[0394] As the conductive layer 152, one or more oxides selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, one or more conductive oxides selected from indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon are preferred. In particular, indium tin oxide containing silicon has a large work function, for example, 4.0 eV or more, so it is suitable for use as the conductive layer 152.

[0395] Conductive layer 151 and conductive layer 152 may each have a stacked structure containing multiple layers of different materials. In this case, conductive layer 151 may also include a layer using a material that can be used in conductive layer 152, such as a conductive oxide, and conductive layer 152 may also include a layer using a material that can be used in conductive layer 151, such as a metallic material. For example, when conductive layer 151 has a stacked structure of two or more layers, the layer in contact with conductive layer 152 may be a layer using a material that can be used in conductive layer 152.

[0396] Next, referring to Figures 5 to 10, the following describes the product with... Figure 4AAn example of a manufacturing method for the display device 100 with the structure shown. Note that the following describes a method for manufacturing a light-emitting device without using a metal mask; however, the light-emitting device or display device of one aspect of the present invention can of course also be manufactured by a conventional vapor deposition method using a metal mask.

[0397] [Example 1 of manufacturing method] Thin films (insulating films, semiconductor films, and conductive films, etc.) that make up a display device can be formed using sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), or ALD.

[0398] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using wet deposition methods such as spin coating, dip coating, spray coating, inkjet coating, dispenser coating, screen printing, offset printing, doctor knife coating, slot coating, roller coating, curtain coating, or doctor knife coating.

[0399] Furthermore, when processing the thin film constituting the display device, photolithography can be used, for example.

[0400] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm), or a mixture of these. Alternatively, ultraviolet light, KrF lasers, or ArF lasers can also be used. Furthermore, immersion lithography can be employed. Additionally, extreme ultraviolet (EUV) light or X-rays can be used as the light for exposure. Alternatively, an electron beam can be used instead of the light used for exposure.

[0401] In the etching of thin films, dry etching, wet etching, or sandblasting methods can be used.

[0402] Furthermore, in the manufacturing process of light-emitting devices, organic compounds that are excited by absorbing light are used. These excited organic compounds sometimes have a high probability of reacting with oxygen or water in the atmosphere. In other words, when light of a wavelength absorbed by the organic compound is irradiated in the presence of oxygen, the organic compound may sometimes produce deterioration products.

[0403] Therefore, when processing a substrate with organic compounds formed using photolithography, it is preferable to perform the above processing under appropriately controlled lighting conditions when exposed to the atmosphere. Ideally, the above processing should be performed in an environment using illumination that does not excite the organic compounds through light absorption. However, to ensure that the illuminance or color rendering does not decrease in efficiency, it is preferable to use illumination where the light-emitting end of the emission spectrum of the light source is at the shortest wavelength of 600 nm or less, preferably 580 nm or less.

[0404] For example, as illumination, a yellow lamp (fluorescent lamp or light-emitting diode (LED)) that does not emit light with wavelengths shorter than 500 nm is preferred. Furthermore, an orange lamp (fluorescent lamp or light-emitting diode (LED)) that does not emit light with wavelengths shorter than 530 nm is preferred. Low-pressure sodium lamps can also be used. Additionally, illumination employing optical filters capable of blocking light at short wavelengths can be used, such as incandescent lamps, fluorescent lamps, LEDs, halogen lamps, and sunlight. For example, bandpass filters and longpass filters (short-wavelength filtering filters) can be used as optical filters capable of blocking light at short wavelengths. Furthermore, by using the above-described illumination, the illuminance of the illumination light can be reduced.

[0405] First, such as Figure 3A As shown, an insulating layer 171 is formed on a substrate (not shown). Next, a conductive layer 172 and a conductive layer 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 to cover the conductive layers 172 and 179. Next, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0406] As a substrate, a substrate with heat resistance sufficient to withstand the subsequent heat treatment can be used. Examples of substrates that can be used include: glass substrates; quartz substrates; sapphire substrates; ceramic substrates; organic resin substrates; single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of materials such as silicon or silicon carbide; compound semiconductor substrates made of materials such as silicon and germanium; SOI substrates, etc.

[0407] Next, as Figure 5A As shown, openings leading to the conductive layer 172 are formed in insulating layers 175, 174, and 173. Then, a plug 176 is formed by embedding it into these openings.

[0408] Next, as Figure 5AAs shown, conductive films 151f, which become conductive layers 151R, 151G, 151B, and 151C, and conductive films 152f, which become conductive layers 152R, 152G, 152B, and 152C, are formed on plug 176 and insulating layer 175. Conductive film 151f can be made of, for example, a metallic material. Conductive film 152f can be made of, for example, one or more oxides selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon.

[0409] Next, as Figure 5A As shown, a resist mask 191 is formed on the conductive film 152f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then exposing and developing it.

[0410] Next, as Figure 5B As shown, for example, the conductive films 151f and 152f in areas that do not overlap with the resist mask 191 are removed. Thus, conductive layers 151 and 152 are formed.

[0411] Next, as Figure 5C As shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0412] Next, as Figure 5D As shown, an insulating film 156f is formed on conductive layers 152R, 152G, 152B, 152C and insulating layer 175, which will subsequently become insulating layers 156R, 156G, 156B and 156C.

[0413] Insulating film 156f can be inorganic insulating films such as oxide insulating film, nitride insulating film, oxynitride insulating film or oxynitride insulating film, for example, silicon oxynitride can be used.

[0414] Next, as Figure 5E As shown, insulating layers 156R, 156G, 156B and 156C are formed by processing insulating film 156f.

[0415] Next, as Figure 6A As shown, an organic compound film 103Rf is formed on conductive layers 152R, 152G, 152B, and insulating layer 175. Furthermore, as... Figure 6A As shown, no organic compound film 103Rf is formed on the conductive layer 152C.

[0416] Next, as Figure 6A As shown, a sacrificial film 158Rf and a mask film 159Rf are formed.

[0417] By setting a sacrificial film 158Rf on the organic compound film 103Rf, the damage to the organic compound film 103Rf during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0418] The sacrificial film 158Rf is a film with high tolerance to the processing conditions of the organic compound film 103Rf, specifically a film with a greater etch selectivity than the organic compound film 103Rf. The mask film 159Rf is a film with a greater etch selectivity than the sacrificial film 158Rf.

[0419] Furthermore, the sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat resistance temperature of the organic compound film 103Rf. The substrate temperature during the formation of the sacrificial film 158Rf and the mask film 159Rf is typically 100°C or higher and 200°C or lower, preferably 100°C or higher and 150°C or lower, and more preferably 100°C or higher and 120°C or lower. Since the light-emitting device of one aspect of the present invention comprises a first compound, a display device with good display quality even after a heating process at a higher temperature can be provided.

[0420] The sacrificial film 158Rf and the mask film 159Rf are preferably films that can be removed by wet etching or dry etching.

[0421] The sacrificial film 158Rf formed on the organic compound film 103Rf is preferably formed by a method that causes less damage to the organic compound film 103Rf compared to the formation of the mask film 159Rf. For example, ALD or vacuum evaporation is more preferred than sputtering.

[0422] As the sacrificial film 158Rf and the mask film 159Rf, one or more of the following can be used: metal film, alloy film, metal oxide film, semiconductor film, organic insulating film and inorganic insulating film.

[0423] The sacrificial film 158Rf and the mask film 159Rf can each be made of metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloys containing such metallic materials. Low-melting-point materials such as aluminum or silver are particularly preferred. By using a metallic material capable of blocking ultraviolet light as one or both of the sacrificial film 158Rf and the mask film 159Rf, ultraviolet light irradiation on the organic compound film 103Rf during pattern exposure can be suppressed, thereby inhibiting the degradation of the organic compound film 103Rf, which is therefore preferred.

[0424] In addition, the sacrificial film 158Rf and the mask film 159Rf can each be metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), or indium tin oxide containing silicon.

[0425] Note that element M (selected from one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) can also be used in place of gallium in the above metal oxides.

[0426] As the sacrificial film 158Rf and the mask film 159Rf, semiconductor materials such as silicon or germanium are preferred due to their high affinity for semiconductor manufacturing processes. Alternatively, compounds containing the aforementioned semiconductor materials can be used.

[0427] Furthermore, various inorganic insulating films can be used as both the sacrificial film 158Rf and the mask film 159Rf. In particular, the oxide insulating film exhibits better adhesion to the organic compound film 103Rf compared to the nitrided insulating film, and is therefore preferred.

[0428] Next, as Figure 6A As shown, a photoresist mask 190R is formed. The photoresist mask 190R can be formed by applying a photosensitive material (photoresist) and then exposing and developing it.

[0429] The resist mask 190R is disposed at a position overlapping with the conductive layer 152R. Preferably, the resist mask 190R is also disposed at a position overlapping with the conductive layer 152C. This can suppress damage to the conductive layer 152C during the manufacturing process of the display device.

[0430] Next, as Figure 6B As shown, a portion of the mask film 159Rf is removed using a resist mask 190R, thereby forming a mask layer 159R. The mask layer 159R remains on the conductive layers 152R and 152C. Then, the resist mask 190R is removed. Next, the mask layer 159R is used as a mask (also called a hard mask) to remove a portion of the sacrificial film 158Rf to form the sacrificial layer 158R.

[0431] By using wet etching, damage to the organic compound film 103Rf can be reduced during the processing of the sacrificial film 158Rf and the mask film 159Rf compared to dry etching. When using wet etching, it is preferable to use, for example, an alkaline aqueous solution such as a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), or an acidic aqueous solution such as dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0432] In addition, when dry etching is used in the processing of sacrificial film 158Rf, the degradation of organic compound film 103Rf can be suppressed by not using oxygen-containing gas as etching gas.

[0433] The resist mask 190R can be removed using the same method as the resist mask 191.

[0434] Next, as Figure 6B As shown, the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as a hard mask to remove part of the organic compound film 103Rf to form the organic compound layer 103R.

[0435] Therefore, as Figure 6B As shown, the conductive layer 152R has a stacked structure of organic compound layer 103R, sacrificial layer 158R, and mask layer 159R remaining on it. In addition, conductive layers 152G and 152B are exposed.

[0436] The organic compound film 103Rf is preferably processed using anisotropic etching. Anisotropic dry etching is particularly preferred. Alternatively, wet etching may also be used.

[0437] When using dry etching, the degradation of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas.

[0438] Alternatively, oxygen-containing gases can be used as etching gases. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed at low power conditions while maintaining a sufficient etching rate. This suppresses damage to the organic compound film 103Rf. Furthermore, it suppresses defects such as the adhesion of reaction products generated during etching.

[0439] When using dry etching, it is preferable to use a gas containing one or more Group 18 elements such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, and He or Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of the above-mentioned gases and oxygen as the etching gas. Oxygen gas may also be used as the etching gas.

[0440] Next, as Figure 7A As shown, an organic compound film 103Gf is formed, which subsequently becomes an organic compound layer 103G.

[0441] The organic compound membrane 103Gf can be formed using the same method as that used in forming the organic compound membrane 103Rf. Furthermore, the organic compound membrane 103Gf can have the same structure as the organic compound membrane 103Rf.

[0442] Next, as Figure 7A As shown, a sacrificial film 158Gf and a mask film 159Gf are formed sequentially. Then, a resist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as those used for the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190G are the same as those used for the resist mask 190R.

[0443] The resist mask 190G is positioned at the location where it overlaps with the conductive layer 152G.

[0444] Next, as Figure 7B As shown, a portion of the mask film 159Gf is removed using a photoresist mask 190G, thereby forming a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the photoresist mask 190G is removed. Next, the mask layer 159G is used as part of the mask removal sacrificial film 158Gf to form a sacrificial layer 158G. Then, an organic compound film 103Gf is processed to form an organic compound layer 103G.

[0445] Next, as Figure 7C As shown, an organic compound film 103Bf is formed.

[0446] The organic compound membrane 103Bf can be formed using the same method as that used in forming the organic compound membrane 103Rf. Furthermore, the organic compound membrane 103Bf can have the same structure as the organic compound membrane 103Rf.

[0447] Next, as Figure 7C As shown, a sacrificial film 158Bf and a mask film 159Bf are formed sequentially. Then, a resist mask 190B is formed. The materials and formation methods of the sacrificial film 158Bf and the mask film 159Bf are the same as those used for the sacrificial film 158Rf and the mask film 159Rf. The materials and formation method of the resist mask 190B are the same as those used for the resist mask 190R.

[0448] The resist mask 190B is disposed at a position overlapping the conductive layer 152B.

[0449] Next, as Figure 7DAs shown, a portion of the mask film 159Bf is removed using a photoresist mask 190B, thereby forming a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Then, the photoresist mask 190B is removed. Next, the mask layer 159B is used as part of the mask removal sacrificial film 158Bf to form a sacrificial layer 158B. Next, an organic compound film 103Bf is processed to form an organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as part of the hard mask removal organic compound film 103Bf to form the organic compound layer 103B.

[0450] Therefore, as Figure 7D As shown, the conductive layer 152B has a stacked structure of organic compound layer 103B, sacrificial layer 158B, and mask layer 159B remaining on it. In addition, mask layer 159R and mask layer 159G are exposed.

[0451] Note that the side surfaces of organic compound layers 103R, 103G, and 103B are preferably perpendicular to or substantially perpendicular to the surface to which they are formed. For example, the angle formed between the surface to which they are formed and these side surfaces is preferably 60 degrees or more and 90 degrees or less.

[0452] As described above, the distance between adjacent organic compound layers 103R, 103G, and 103B formed by photolithography can be reduced to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. This distance can be specified, for example, based on the distance between the opposite ends of two adjacent organic compound layers 103R, 103G, and 103B. Thus, by reducing the distance between the island-shaped organic compound layers, a display device with high resolution and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be reduced, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. Moreover, the distance between the first electrodes of adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0453] Next, as Figure 8A As shown, it is preferable to remove mask layer 159R, mask layer 159G and mask layer 159B.

[0454] The mask layer removal process can use the same method as the mask film processing process. In particular, by using wet etching, damage to the organic compound layer 103 during mask layer removal can be reduced compared to using dry etching.

[0455] Alternatively, the mask layer can be removed by dissolving it in a polar solvent such as water or alcohol. Examples of alcohols include ethanol, methanol, isopropanol (IPA), or glycerol.

[0456] After removing the mask layer, a drying process can be performed to remove water adsorbed on the surface. For example, heating treatment can be performed under an inert gas atmosphere or a reduced pressure atmosphere. The heating treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. By using a reduced pressure atmosphere, drying can be performed at a lower temperature, which is preferred.

[0457] Next, as Figure 8B As shown, an inorganic insulating film 125f is formed.

[0458] Next, as Figure 8C As shown, an insulating film 127f, which will later become an insulating layer 127, is formed on an inorganic insulating film 125f.

[0459] The substrate temperature for forming the inorganic insulating film 125f and the insulating film 127f is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower.

[0460] As the inorganic insulating film 125f, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and a thickness of 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above-mentioned substrate temperature range.

[0461] The inorganic insulating film 125f is preferably formed using the ALD method, for example. The ALD method reduces deposition damage and allows for the deposition of films with high coverage, making it preferred. For example, an alumina film is preferably formed using the ALD method as the inorganic insulating film 125f.

[0462] The insulating film 127f is preferably formed using the wet deposition method described above. The insulating film 127f is preferably formed, for example, by spin coating using a photosensitive material, and more specifically, preferably by using a photosensitive resin composition containing acrylic resin.

[0463] Next, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. The insulating layer 127 is formed in the region sandwiched by any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C.

[0464] By utilizing the area exposed to the insulating film 127f, the width of the subsequently formed insulating layer 127 can be controlled. In this embodiment, the insulating layer 127 is processed such that it has a portion overlapping the top surface of the conductive layer 151.

[0465] The light used for exposure preferably has an i-line (wavelength 365 nm). Alternatively, the light used for exposure may also have at least one of a g-line (wavelength 436 nm) and an h-line (wavelength 405 nm).

[0466] Next, as Figure 9A As shown, the exposed areas in the insulating film 127f are removed by developing to form the insulating layer 127a.

[0467] Next, as Figure 9B As shown, an etching process using insulating layer 127a as a mask removes a portion of the inorganic insulating film 125f, thereby reducing the thickness of a portion of sacrificial layers 158R, 158G, and 158B. This forms an inorganic insulating layer 125 beneath insulating layer 127a. Furthermore, the surfaces of the thinner portions of sacrificial layers 158R, 158G, and 158B are exposed. The etching process using insulating layer 127a as a mask is sometimes referred to as the first etching process.

[0468] The first etching process can be performed by dry etching or wet etching. When the inorganic insulating film 125f is deposited using the same material as the sacrificial layers 158R, 158G, and 158B, the first etching process can be performed simultaneously, which is therefore preferred.

[0469] When performing dry etching, chlorine-based gases are preferred. One or more of the following chlorine-based gases can be used: Cl2, BCl3, SiCl4, and CCl4. Alternatively, one or more of the following gases can be appropriately added to the chlorine-based gas: oxygen, hydrogen, helium, and argon. By utilizing dry etching, regions with thin sacrificial layers 158R, 158G, and 158B can be formed with excellent in-plane uniformity.

[0470] As a dry etching apparatus, a dry etching apparatus with a high-density plasma source can be used. For example, an inductively coupled plasma (ICP) etching apparatus can be used as a dry etching apparatus with a high-density plasma source. Alternatively, a capacitively coupled plasma (CCP) etching apparatus including parallel planar electrodes can be used.

[0471] Furthermore, wet etching is preferred for the first etching process. Compared to dry etching, wet etching further reduces damage to the organic compound layers 103R, 103G, and 103B. For example, wet etching can be performed using an alkaline solution. For instance, TMAH of an alkaline solution can be used in the wet etching of the alumina film. Additionally, an acidic solution containing fluoride can be used. In this case, wet etching can be performed by coating. When the inorganic insulating film 125f is deposited using the same material as the sacrificial layers 158R, 158G, and 158B, the above etching process can be performed simultaneously, which is therefore preferred.

[0472] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed; the etching process is stopped when the thickness is reduced. Thus, by leaving corresponding sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, damage to the organic compound layers 103R, 103G, and 103B can be prevented during subsequent processing steps.

[0473] Next, the entire substrate is preferably exposed to visible or ultraviolet light onto the insulating layer 127a. The energy density of this exposure is preferably greater than 0 mJ / cm². 2 And it is 800mJ / cm 2 Below, greater than 0 mJ / cm is preferred. 2 And it is 500mJ / cm 2 The following applies. By performing this exposure after development, the transparency of the insulating layer 127a can sometimes be improved. Additionally, the substrate temperature required for the subsequent heat treatment to deform the insulating layer 127a into a conical shape can sometimes be reduced.

[0474] Here, by providing an oxygen-blocking insulating layer (such as an aluminum oxide film) as a sacrificial layer 158R, sacrificial layer 158G and sacrificial layer 158B, oxygen diffusion to organic compound layer 103R, organic compound layer 103G and organic compound layer 103B can be suppressed.

[0475] Next, a heat treatment (also known as post-baking) is performed. This heat treatment deforms the insulating layer 127a into an insulating layer 127 with a tapered shape on its sides. Figure 9CThe heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 130°C or lower. The heating atmosphere can be either atmospheric or an inert gas. Furthermore, the heating atmosphere can be either atmospheric or a reduced-pressure atmosphere. This improves the adhesion between the insulating layer 127 and the inorganic insulating layer 125, and also improves the corrosion resistance of the insulating layer 127.

[0476] In the first etching process, by not completely removing the sacrificial layers 158R, 158G, and 158B, leaving them in a thinned state, damage and deterioration of the organic compound layers 103R, 103G, and 103B can be prevented during the heat treatment. This improves the reliability of the light-emitting device.

[0477] Next, as Figure 10A As shown, the insulating layer 127 is used as a mask for etching to remove a portion of the sacrificial layers 158R, 158G, and 158B. This creates openings in the sacrificial layers 158R, 158G, and 158B, exposing the top surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C. Note that this etching process is sometimes referred to below as the second etching process.

[0478] The ends of the inorganic insulating layer 125 are covered by the insulating layer 127. Additionally, Figure 10A An example is shown where a portion of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered by the insulating layer 127 and the tapered portion formed by the second etching process is exposed.

[0479] The second etching process is performed using wet etching. Compared to dry etching, wet etching further reduces damage to the organic compound layers 103R, 103G, and 103B. For example, wet etching can be performed using an alkaline or acidic solution. To prevent dissolution of the organic compound layer 103, an aqueous solution is preferred.

[0480] Next, as Figure 10B As shown, a common electrode 155 is formed on organic compound layers 103R, 103G, 103B, conductive layer 152C, and insulating layer 127. The common electrode 155 can be formed by methods such as sputtering or vacuum evaporation.

[0481] Next, as Figure 10C As shown, a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed using methods such as vacuum evaporation, sputtering, CVD, or ALD. The protective layer 131 can also serve as a capping layer. By providing a capping layer, the light extraction efficiency can be improved when the light-emitting device is a top-emitting type. For example, by using a material with an ordinary refractive index (no) of 1.90 or higher at a wavelength of 450 nm, a material with an ordinary refractive index (no) of 1.80 or higher at a wavelength of 520 nm, or a material with an ordinary refractive index (no) of 1.75 or higher at a wavelength of 630 nm, total internal reflection of light from the organic compound layer 103 in the capping layer can be prevented, thereby improving the light extraction efficiency.

[0482] Furthermore, to prevent the light-emitting device from being exposed to the atmosphere before being assembled into the display device or light-emitting device, a sealing film may be provided on the protective layer 131. This sealing film can be made of a material that is not easily permeable to impurities such as water. Specifically, it is preferable to use the ALD method to provide an alumina film. Note that to prevent the light-emitting device from being exposed to the atmosphere before the sealing film is provided after the formation of the protective layer 131, it is preferable to move the light-emitting device into the ALD device in a glove box under a nitrogen atmosphere after the formation of the protective layer 131. At this time, the oxygen concentration in the glove box is preferably 100 ppm or less, more preferably 10 ppm or less, and even more preferably 1 ppm or less.

[0483] Next, the substrate 120 is bonded to the protective layer 131 using the resin layer 122, thereby manufacturing a display device. As described above, in one embodiment of the manufacturing method of the display device of the present invention, the insulating layer 156 is provided such that it overlaps with the side surface of the conductive layer 151, and the conductive layer 152 is formed such that it covers the conductive layer 151 and the insulating layer 156. This improves the yield of the display device and suppresses defects. Alternatively, a display device with a microlens array can be manufactured by providing a microlens array on the protective layer 131 or the sealing film before bonding the substrate 120 and then bonding the substrate 120.

[0484] As described above, in one aspect of the manufacturing method of the display device of the present invention, the island-shaped organic compound layer 103R, island-shaped organic compound layer 103G, and island-shaped organic compound layer 103B are not formed using a high-precision metal mask, but are formed by depositing a film on one surface and then processing it, thus allowing the island-shaped layers to be formed with a uniform thickness. Furthermore, a high-resolution display device or a display device with a high aperture ratio can be achieved. Moreover, even with high resolution or aperture ratio and extremely short distances between sub-pixels, contact between organic compound layers 103R, organic compound layer 103G, and organic compound layer 103B in adjacent sub-pixels can be suppressed. Therefore, leakage current between sub-pixels can be suppressed. Thus, crosstalk can be suppressed, and a display device with extremely high contrast can be achieved. Furthermore, even display devices including tandem light-emitting devices manufactured using photolithography can provide display devices with excellent characteristics.

[0485] (Implementation Method 4) In this embodiment, a display device according to one aspect of the present invention will be described.

[0486] The display device in this embodiment can be a high-definition display device. Therefore, for example, the display device in this embodiment can be used as the display unit of information terminal devices (wearable devices) such as watch-type and bracelet-type devices, as well as the display unit of wearable devices that can be worn on the head, such as head-mounted displays (HMDs) for VR devices and glasses-type AR devices.

[0487] Furthermore, the display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used, for example, as a display unit for devices such as: electronic devices with large screens, such as television sets, desktop or laptop personal computers, monitors for computers, digital signage, and large game machines such as pinball machines; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; portable information terminals; and sound reproduction devices.

[0488] [Display Module] Figure 11A A perspective view of display module 280 is shown. Display module 280 includes display device 100A and FPC 290. Note that the display device included in display module 280 is not limited to display device 100A, but may be any of display devices 100B to 100E described later.

[0489] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display section 281. The display section 281 is the image display area in the display module 280, and can display light from each pixel disposed in the pixel section 284.

[0490] Figure 11B This is a three-dimensional schematic diagram of the structure on one side of the substrate 291. A circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked on the substrate 291. Furthermore, a terminal section 285 for connecting to the FPC 290 is provided on a portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 is electrically connected to the circuit section 282 via a wiring section 286 composed of multiple wirings.

[0491] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 11b. Pixel 284a can adopt various structures described in the above embodiments.

[0492] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0493] A pixel circuit 283a controls the driving of multiple elements included in a pixel 284a.

[0494] The circuit section 282 includes circuitry for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. Furthermore, it may include at least one of an arithmetic circuit, a storage circuit, and a power supply circuit.

[0495] The FPC290 is used for wiring to supply video signals or power potentials, etc., from the outside to the circuit section 282. Additionally, ICs can be mounted on the FPC290.

[0496] The display module 280 can adopt a structure in which one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, so that the display section 281 can have an extremely high aperture ratio (effective display area ratio).

[0497] This high-definition display module 280 is suitable for use in VR devices such as HMDs or glasses-type AR devices. For example, because the display module 280 has an extremely high-definition display section 281, even when the user views the display section of the display module 280 through a lens and magnifies the display section with the lens, the pixels are not visible, thereby achieving a highly immersive display. Furthermore, the display module 280 can also be applied to electronic devices with relatively small display sections.

[0498] [Display Device 100A] Figure 12A The display device 100A shown includes a substrate 301, light-emitting devices 130R, 130G, 130B, a capacitor 240, and a transistor 310.

[0499] Substrate 301 is equivalent to Figure 12A and Figure 12B The substrate 291 is used in the transistor 310. The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 includes a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 serves as the gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and serves as the gate insulating layer. The low-resistance region 312 is a region in the substrate 301 doped with impurities and serves as the source or drain. The insulating layer 314 covers the sides of the conductive layer 311.

[0500] In addition, a component separation layer 315 is provided between two adjacent transistors 310 in a manner embedded in the substrate 301.

[0501] In addition, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0502] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 serves as one electrode in the capacitor 240, the conductive layer 245 serves as the other electrode in the capacitor 240, and the insulating layer 243 serves as the dielectric of the capacitor 240.

[0503] A conductive layer 241 is disposed on an insulating layer 261 and embedded within an insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain terminals of the transistor 310 via a connector 271 embedded in the insulating layer 261. An insulating layer 243 is disposed to cover the conductive layer 241. A conductive layer 245 is disposed in the region where it overlaps with the conductive layer 241, separated by the insulating layer 243.

[0504] An insulating layer 255 is provided to cover the capacitor 240, and an insulating layer 174 is provided on the insulating layer 255. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. Insulators are provided in the areas between adjacent light-emitting devices.

[0505] An insulating layer 156R is provided such that it includes a region overlapping the side surface of conductive layer 151R, an insulating layer 156G is provided such that it includes a region overlapping the side surface of conductive layer 151G, and an insulating layer 156B is provided such that it includes a region overlapping the side surface of conductive layer 151B. Furthermore, a conductive layer 152R is provided such that it covers conductive layer 151R and insulating layer 156R, a conductive layer 152G is provided such that it covers conductive layer 151G and insulating layer 156G, and a conductive layer 152B is provided such that it covers conductive layer 151B and insulating layer 156B. A sacrificial layer 158R is located on organic compound layer 103R, a sacrificial layer 158G is located on organic compound layer 103G, and a sacrificial layer 158B is located on organic compound layer 103B.

[0506] Conductive layers 151R, 151G, and 151B are electrically connected to one of the source and drain terminals of transistor 310 via plugs 256 embedded in insulating layers 243, 255, 174, and 175, conductive layer 241 embedded in insulating layer 254, and plug 271 embedded in insulating layer 261. The plugs can be made of various conductive materials.

[0507] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. Detailed descriptions of the constituent elements of the light-emitting devices 130 and 120 can be found in Embodiment 3. The substrate 120 corresponds to... Figure 11A Substrate 292.

[0508] Figure 12B Show Figure 12A A modified example of the display device 100A shown. Figure 12B The display device shown includes a color layer 132R, a color layer 132G, and a color layer 132B, and a light-emitting device 130 has a region overlapping one of the color layers 132R, 132G, and 132B. Figure 12B In the display device shown, the light-emitting device 130 can emit white light, for example. In addition, for example, the color layer 132R, color layer 132G and color layer 132B can transmit red light, green light and blue light respectively.

[0509] [Display device 100B] Figure 13 A perspective view of the display device 100B is shown. Figure 14 A cross-sectional view of the display device 100C is shown.

[0510] The display device 100B has a structure that bonds substrate 352 and substrate 351. Figure 13 In the image, substrate 352 is represented by a dashed line.

[0511] The display device 100B includes a pixel unit 177, a connection unit 140, a circuit 356, and wiring 355, etc. Figure 13 An example is shown where display device 100B is equipped with IC354 and FPC353. Therefore, it is also possible to... Figure 13 The structure shown is referred to as a display module including a display device 100B, an IC (integrated circuit), and an FPC. Here, the substrate of the display device on which connectors such as the FPC are mounted, or the substrate on which the IC is mounted, is referred to as the display module.

[0512] The connecting portion 140 is disposed on the outer side of the pixel portion 177. There may be one or more connecting portions 140. In the connecting portion 140, the common electrode of the light-emitting device is electrically connected to the conductive layer, and power can be supplied to the common electrode.

[0513] For example, a scan line drive circuit can be used as circuit 356.

[0514] Wiring 355 has the function of supplying signals and power to pixel unit 177 and circuit 356. The signals and power are input to wiring 355 from the outside via FPC 353 or from IC 354.

[0515] Figure 13 An example is shown where IC 354 is mounted on substrate 351 using methods such as COG (Chip On Glass) or COF (Chip On Film). IC 354 can be, for example, an IC including scan line drive circuitry or signal line drive circuitry. Note that the display device 100B and display module do not necessarily need to have an IC mounted on them. Alternatively, the IC can also be mounted on an FPC using COF.

[0516] Figure 14 As shown in display device 100C Figure 13 An example of a cross-section of a display device 100B including a portion of an area of ​​FPC 353, a portion of circuitry 356, a portion of pixel portion 177, a portion of connection portion 140, and a portion of an area including an end portion.

[0517] [Display Device 100C] Figure 14 The display device 100C shown includes transistors 201 and 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc., between substrates 351 and 352.

[0518] For details on light-emitting devices 130R, 130G, and 130B, please refer to Embodiment 3.

[0519] Light-emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. Light-emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. Light-emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B.

[0520] The conductive layer 224R is connected to the conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. The insulating layer 156R is provided in such a way that it includes a region that contacts the side of the conductive layer 151R, and the conductive layer 152R is provided in such a way that it covers the conductive layer 151R and the insulating layer 156R.

[0521] The conductive layers 224G, 151G, 152G, and 156G in the light-emitting device 130G, and the conductive layers 224B, 151B, 152B, and 156B in the light-emitting device 130B, are the same as the conductive layers 224R, 151R, 152R, and 156R in the light-emitting device 130R, so detailed descriptions are omitted.

[0522] The conductive layers 224R, 224G, and 224B have recesses formed in a manner that cover the openings provided in the insulating layer 214. These recesses are filled with layer 128.

[0523] Layer 128 has the function of filling the recesses of conductive layers 224R, 224G, and 224B to planarize them. Conductive layers 151R, 151G, and 151B, which are electrically connected to conductive layers 224R, 224G, and 224B, are disposed on conductive layers 224R, 224G, and 224B. Therefore, the area overlapping the recesses of conductive layers 224R, 224G, and 224B can also be used as a light-emitting area, which can improve the pixel aperture ratio.

[0524] Layer 128 can also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be suitably used for layer 128. In particular, layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. Layer 128 can, for example, use the organic insulating material described above that can be used in insulating layer 127.

[0525] A protective layer 131 is provided on light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 352 are bonded together by an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. The light-emitting device 130 can be sealed using a solid sealing structure or a hollow sealing structure, etc. Figure 14 In this configuration, the space between substrates 352 and 351 is filled with adhesive layer 142, thus employing a solid sealing structure. Alternatively, an inert gas (such as nitrogen or argon) can be used to fill the space, resulting in a hollow sealing structure. In this case, adhesive layer 142 can also be arranged in a manner that does not overlap with the light-emitting device. Furthermore, a resin different from that used for the frame-shaped adhesive layer 142 can be used to fill the space.

[0526] Figure 14 An example is shown below: the connecting portion 140 includes a conductive layer 224C obtained by processing a conductive film identical to conductive layers 224R, 224G, and 224B; a conductive layer 151C obtained by processing a conductive film identical to conductive layers 151R, 151G, and 151B; and a conductive layer 152C obtained by processing a conductive film identical to conductive layers 152R, 152G, and 152B. Furthermore, Figure 14 An example is shown in which the insulating layer 156C is disposed in such a manner that it includes a region that overlaps with the side of the conductive layer 151C.

[0527] Display device 100C is a top-emitting display device. The light-emitting device emits light onto one side of substrate 352. Substrate 352 is preferably made of a material with high transmittance to visible light. Pixel electrodes contain a material that reflects visible light, and counter electrodes (common electrodes 155) contain a material that allows visible light to pass through.

[0528] Insulating layers 211, 213, 215, and 214 are sequentially disposed on substrate 351. A portion of insulating layer 211 serves as the gate insulating layer for each transistor. A portion of insulating layer 213 serves as the gate insulating layer for each transistor. Insulating layer 215 is disposed to cover the transistor. Insulating layer 214 is disposed to cover the transistor and serves as a planarization layer. Furthermore, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistor; there can be one or more.

[0529] Inorganic insulating films are preferably used as insulating layers 211, 213 and 215.

[0530] The insulating layer 214 used as the planarization layer is preferably an organic insulating layer.

[0531] Transistor 201 and transistor 205 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as source and drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate.

[0532] A connection portion 204 is provided in a region of substrate 351 that does not overlap with substrate 352. In the connection portion 204, the source or drain electrode of transistor 201 is electrically connected to FPC 353 via conductive layer 166 and connection layer 242. An example is shown where conductive layer 166 has a stacked structure consisting of a conductive film processed from the same conductive films as conductive layers 224R, 224G, and 224B; a conductive film processed from the same conductive films as conductive layers 151R, 151G, and 151B; and a conductive film processed from the same conductive films as conductive layers 152R, 152G, and 152B. Conductive layer 166 is exposed on the top surface of connection portion 204. Therefore, connection portion 204 can be electrically connected to FPC 353 via connection layer 242.

[0533] Preferably, a light-shielding layer 157 is provided on the surface of the substrate 352 on the substrate 351 side. The light-shielding layer 157 can be provided between adjacent light-emitting devices, in the connection portion 140, and in the circuit 356, etc. In addition, various optical components can be arranged on the outer side of the substrate 352.

[0534] Substrate 351 and substrate 352 may each be made of a material that can be used in substrate 120.

[0535] As the adhesive layer 142, a material suitable for the resin layer 122 can be used.

[0536] As the connecting layer 242, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0537] [Display Device 100D] Figure 15 The display device 100D shown is Figure 14 The main difference between the display device 100C shown is that the former is a bottom-emitting type display device.

[0538] The light emitted by the light-emitting device is directed onto one side of the substrate 351. The substrate 351 is preferably made of a material with high transmittance to visible light. On the other hand, there are no restrictions on the transmittance of the material used for the substrate 352.

[0539] Preferably, a light-shielding layer 317 is formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 15 An example is shown where a light-shielding layer 317 is disposed on a substrate 351, an insulating layer 153 is disposed on the light-shielding layer 317, and transistors 201, 205, etc. are disposed on the insulating layer 153.

[0540] The light-emitting device 130R includes a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0541] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0542] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B are all made of materials with high transmittance to visible light. The second electrode 102 is preferably made of a material that reflects visible light.

[0543] Note that, although Figure 15 The light-emitting device 130G is not shown in the figure, but it is also provided.

[0544] in addition, Figure 15 Examples are shown where the top surface of layer 128 has a flat portion, but there are no particular restrictions on the shape of layer 128.

[0545] [Display Device 100D2] The display device 100D2 shown in Figure 16 is related to Figure 15 This is an example of a bottom-emitting display device different from the display device 100D shown. The display device 100D2 differs from the display device 100D in that the former includes an organic resin layer 180. Note that details are sometimes omitted in the accompanying drawings. Figure 15 For details regarding symbols representing the same constituent elements, please refer to [link / reference]. Figure 15 The records.

[0546] in addition, Figure 16B The diagram shows a top view layout of pixels 178 (pixels 178a and 178b) including sub-pixels 110 (sub-pixels 110R, 110G, 110B, and 110W). Figure 16C A top view of the organic resin layer 180 in the region forming sub-pixels 110R and 110G included in pixel 178 is shown. Note that the width 110Rw in the light-emitting region of sub-pixel 110R is between the light-shielding layers 317 and 317.

[0547] like Figure 16AAs shown, the organic resin layer 180 is disposed on the insulating layer 214. (As indicated...) Figure 16A The area enclosed by the dotted line and Figure 16C As shown, the organic resin layer 180 includes, at least in the region forming the sub-pixel, a recess 181 (recess 181a, recess 181b) with a curved surface. Note that the recess 181 may also be disposed outside the light-emitting region, as in the case of recess 181c. By providing this recess 181c, light emitted in the region overlapping with the light-shielding layer 317, or light traveling toward the region overlapping with the light-shielding layer 317, can be refracted and extracted from the light-emitting region to the outside, thereby improving luminous efficiency.

[0548] Multiple recesses 181 can also be formed in a matrix. Recesses 181a and 181b can be arranged in contact with each other or in a way that they are planar with each other.

[0549] Additionally, in Figure 16, the top surface of the recess is hexagonal ( Figure 16C The cross-sectional shape is semi-circular. Figure 16A However, other shapes can also be used as needed. For example, the top surface shape of the concave part can be a triangle, a quadrilateral (including a rectangle and a square), a pentagon or other polygonal shape, the above-mentioned polygonal shapes with rounded corners, an ellipse or a circle, etc.

[0550] As the organic resin layer 180, an insulating layer containing organic materials can be used. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimide amide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be used as the organic resin layer 180. Furthermore, as the organic resin layer 180, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can also be used.

[0551] Furthermore, a photosensitive resin can also be used as the organic resin layer 180. A photoresist can also be used as the photosensitive resin. The photosensitive resin can be either a positive or negative material.

[0552] The organic resin layer 180 may also contain materials that absorb visible light. For example, the organic resin layer 180 itself may be composed of materials that absorb visible light, and the organic resin layer 180 may also contain pigments that absorb visible light. As the organic resin layer 180, for example, resins that can be used as color filters that allow red, blue, or green light to pass through while absorbing other light; or resins that contain carbon black as pigments and are used as black matrices; etc.

[0553] Furthermore, the organic resin layer 180 includes a first electrode 101 (first electrode 101R and first electrode 101W), and the first electrode 101 includes an organic compound layer 103. The ends of the first electrode 101 and the organic compound layer 103 may be covered by an insulating layer 127.

[0554] Furthermore, the first electrode 101 formed on the organic resin layer 180 also has a recess along the recess of the organic resin layer 180. The organic compound layer 103 formed on the first electrode 101 also has a recess along the recess of the first electrode 101. The common layer 104 formed on the organic compound layer 103 also has a recess along the recess of the organic compound layer 103. Furthermore, the second electrode 102 formed on the common layer 104 also has a recess along the recess of the common layer 104. That is, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have an overlapping structure.

[0555] Furthermore, a common layer 104 is included on the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is included on the common layer 104. A protective layer 131 is provided on the second electrode 102, which is bonded to the substrate 352 through an adhesive layer 142.

[0556] Note that although light-emitting devices 130G and 130B are not shown in Figure 16, light-emitting devices 130G and 130B are provided.

[0557] In a light-emitting device of one aspect of the present invention, including the above-described organic resin layer 180, as described in Embodiment 1, the organic compound layer 103 contains an organic compound shown in general formula (Gh1). Due to the inseparable interaction between the organic resin layer 180 and the organic semiconductor device using the organic compound of the present invention, an organic semiconductor device with high luminous efficiency can be provided, as well as an organic semiconductor device with high reliability, low driving voltage, and low power consumption can be provided.

[0558] [Display Device 100E] Figure 17 The display device 100E shown is Figure 14 The illustrated display device 100E is a modified example of the display device 100C, which includes color layer 132R, color layer 132G and color layer 132B, and is the main difference from the display device 100C in this respect.

[0559] In the display device 100E, the light-emitting device 130 has a region overlapping one of the coloring layers 132R, 132G, and 132B. The coloring layers 132R, 132G, and 132B can be disposed on a surface of the substrate 352 on one side of the substrate 351. The ends of the coloring layers 132R, 132G, and 132B can overlap the light-shielding layer 157.

[0560] In the display device 100E, the light-emitting device 130 can emit white light, for example. Additionally, for example, the coloring layers 132R, 132G, and 132B can transmit red, green, and blue light, respectively. Alternatively, the display device 100E may also employ a structure in which the coloring layers 132R, 132G, and 132B are disposed between the protective layer 131 and the adhesive layer 142.

[0561] [Display Device 100E2] The display device 100E2 shown in Figure 18 is... Figure 17 The illustrated display device 100E is a modified example, wherein microlenses 182 are included on color layers 132R, 132G, and 132B. Note that in the drawings, the details of the microlenses 182 are sometimes omitted. Figure 17 For details regarding symbols representing the same constituent elements, please refer to [link / reference]. Figure 17 The records.

[0562] in addition, Figure 18B The diagram shows a top view layout of pixels 178 (pixels 178a and 178b) including sub-pixels 110 (sub-pixels 110R, 110G, and 110B). Figure 18C A top view is shown of the microlens 182 formed in the region comprising sub-pixels 110R and 110G, which are included in pixel 178. Note that the area where the common electrode 155 contacts the organic compound layer 103 is the width 110Gw of the light-emitting region of sub-pixel 110G.

[0563] Figure 18A In the display device 100E2 shown, a planarization film 143 is provided on the protective layer 131, and color layers 132R, 132G, and 132B are provided on the planarization film 144. The planarization film 144 is provided to cover the color layers 132R, 132G, and 132B. A microlens 182 is provided on the planarization film 144.

[0564] In addition, such as Figure 18C As shown, it is preferable to provide a microlens 182 for each sub-pixel in the region where the sub-pixel is formed.

[0565] Note that in Figure 18CIn the microlens 182, the top surface is hexagonal, but other shapes can be used as needed. For example, the top surface shape of the concave portion can be a triangle, a quadrilateral (including a rectangle and a square), a pentagon or other polygonal shape, the above-mentioned polygonal shapes with rounded corners, an ellipse or a circle, etc.

[0566] The microlens 182 can be formed using the same material as the organic resin layer 180.

[0567] In the light-emitting device of one aspect of the present invention, including the microlens 182, as shown in Embodiment 1, the organic compound layer 103 contains an organic compound represented by the general formula (Gh1). Due to the inseparable effect of the microlens 182 and the organic semiconductor device using the organic compound of the present invention, an organic semiconductor device with high luminous efficiency can be provided, and an organic semiconductor device suitable for portable displays with high reliability, low driving voltage, and low power consumption can be provided.

[0568] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, where multiple structural examples are shown in one embodiment in this specification, these structural examples can be appropriately combined.

[0569] (Implementation Method 5) In this embodiment, an electronic device according to one aspect of the present invention will be described.

[0570] The electronic device of this embodiment includes a display device according to one aspect of the present invention in its display unit. The display device according to one aspect of the present invention features low power consumption and high reliability. Therefore, it can be used in the display units of various electronic devices.

[0571] As electronic devices, in addition to large-screen electronic devices such as television sets, desktop or laptop personal computers, monitors for computers, digital signage, and large game machines such as pinball machines, other examples include digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, and sound reproduction devices.

[0572] use Figures 19A to 19D This illustrates an example of a wearable device that can be worn on the head.

[0573] Figure 19A The electronic device 700A shown and Figure 19B The electronic devices 700B shown include a pair of display panels 751, a pair of frames 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical components 753, a frame 757, and a pair of nose pads 758.

[0574] The display panel 751 can be used with a display device according to one aspect of the present invention. Thus, a highly reliable electronic device can be realized.

[0575] Both electronic devices 700A and 700B can project the image displayed by the display panel 751 onto the display area 756 in the optical component 753. Because the optical component 753 is light-transmitting, the user can see the image displayed in the display area by overlapping the image seen through the optical component 753.

[0576] Both electronic devices 700A and 700B can be equipped with cameras capable of capturing images of the front as imaging units. Furthermore, by incorporating accelerometers such as gyroscopes into both electronic devices 700A and 700B, the orientation of the user's head can be detected, and an image corresponding to that orientation can be displayed on the display area 756.

[0577] The communications unit includes a wireless communication device through which video signals can be supplied, for example. Additionally, a connector capable of connecting cables supplying video signals and power potential may be included, either in place of the wireless communication device or in addition to the wireless communication device.

[0578] In addition, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly or via wired means, or both.

[0579] The frame 721 can also be equipped with a touch sensor module.

[0580] Various touch sensors can be used as touch sensor modules. For example, capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be employed. In particular, capacitive or optical sensors are preferred for use in touch sensor modules.

[0581] Figure 19C The electronic device 800A shown and Figure 19D The electronic devices 800B shown include a pair of display units 820, a frame 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0582] The display unit 820 can be equipped with a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0583] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on each of the pair of display units 820, three-dimensional display utilizing parallax can be achieved.

[0584] Electronic devices 800A and 800B preferably have a mechanism in which the left and right positions of the lens 832 and the display unit 820 can be adjusted so that the lens 832 and the display unit 820 are in the most suitable position according to the position of the user's eyes.

[0585] Users can use the mounting unit 823 to attach electronic device 800A or electronic device 800B to their head.

[0586] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras can be set to support various viewing angles such as telephoto and wide-angle.

[0587] The electronic device 800A may also include a vibration mechanism used as a bone conduction headphone.

[0588] Electronic devices 800A and 800B may also include input terminals. For example, cables supplying image signals from image output devices and power for charging batteries installed in the electronic devices can be connected to the input terminals.

[0589] The electronic device of one embodiment of the present invention may also have the function of wireless communication with the earphone 750.

[0590] In addition, electronic devices may also include an earphone unit. Figure 19B The illustrated electronic device 700B includes an earphone unit 727. A portion of the wiring connecting the earphone unit 727 and the control unit may also be configured inside the housing 721 or the mounting unit 723.

[0591] same, Figure 19D The illustrated electronic device 800B includes an earphone unit 827. For example, a structure in which the earphone unit 827 and the control unit 824 are connected in a wired manner can be adopted.

[0592] Thus, as an embodiment of the present invention, both eyeglass type (electronic device 700A and electronic device 700B, etc.) and goggle type (electronic device 800A and electronic device 800B, etc.) are preferred electronic devices.

[0593] Figure 20A The electronic device 6500 shown is a portable information terminal device that can be used as a smartphone.

[0594] Electronic device 6500 includes a frame 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0595] The display unit 6502 can use a display device according to one aspect of the present invention. Therefore, a highly reliable electronic device can be realized.

[0596] Figure 20B It is a cross-sectional schematic diagram of one end of the microphone 6506, including the frame 6501.

[0597] A light-transmitting protective component 6510 is provided on one side of the display surface of the frame 6501. The space surrounded by the frame 6501 and the protective component 6510 contains a display panel 6511, an optical component 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc.

[0598] The display panel 6511, optical component 6512, and touch sensor panel 6513 are fixed to the protective component 6510 using an adhesive layer (not shown).

[0599] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and this folded portion is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals disposed on a printed circuit board 6517.

[0600] The display panel 6511 can be used with a display device according to one aspect of the present invention. This allows for the realization of an extremely lightweight electronic device. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while minimizing the thickness of the electronic device. Additionally, by folding a portion of the display panel 6511 to provide a connection portion with the FPC 6515 on the back of the pixel section, a narrow-bezel electronic device can be achieved.

[0601] Figure 20C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a frame 7171. The structure in which the frame 7171 is supported by a bracket 7173 is shown here.

[0602] The display unit 7000 can use a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0603] It can be operated using the operating switch provided in the housing 7171 and the separately provided remote control 7151. Figure 20C The operation of the television device 7100 shown.

[0604] Figure 20DAn example of a notebook computer is shown. The notebook computer 7200 includes a chassis 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is assembled in the chassis 7211.

[0605] The display unit 7000 can use a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0606] Figure 20E and Figure 20F This shows an example of digital signage that can be used in shop windows and display cases.

[0607] Figure 20E The digital sign 7300 shown includes a frame 7301, a display unit 7000, and a speaker 7303. It may also include LEDs, operation buttons (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0608] Figure 20F A digital sign 7400 is shown mounted on a cylindrical column 7401. The digital sign 7400 includes a display section 7000 disposed along the curved surface of the column 7401.

[0609] exist Figure 20E and Figure 20F In this embodiment, a display device according to one aspect of the present invention can be used in the display unit 7000. This allows for the realization of a highly reliable electronic device.

[0610] The larger the display unit (7000), the more information it can provide at once. A larger display unit (7000) is also more likely to attract attention, which can improve the effectiveness of advertising.

[0611] In particular, when using a display device according to one aspect of the present invention... Figure 20E and Figure 20F In the case of the digital signage 7400 shown, which displays advertisements, the degree of freedom of expression can be increased by using a light-transmitting panel. For example, by adjusting the distance between pixel electrodes using wiring and support members of a conductive film that allows visible lig...

Claims

1. A light-emitting device, comprising: First electrode; Second electrode; Intermediate layer; First luminescent layer; Second light-emitting layer; First electron transport layer; as well as The second electron transport layer, The intermediate layer is located between the first electrode and the second electrode. The first light-emitting layer is located between the first electrode and the intermediate layer. The second light-emitting layer is located between the intermediate layer and the second electrode. The first electron transport layer is located between the first light-emitting layer and the intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode. The first light-emitting layer comprises a first fluorescent light-emitting material, a first organic compound, and a second organic compound. The second light-emitting layer comprises a second fluorescent light-emitting material, a third organic compound, and a fourth organic compound. The difference between the maximum peak wavelength in the emission spectrum of the first fluorescent luminescent material and the maximum peak wavelength in the emission spectrum of the second fluorescent luminescent material is less than 30 nm. Furthermore, the first fluorescent luminescent material and the second fluorescent luminescent material exhibit luminescence of different hues from the luminescent center material in the luminescent layer of at least one of a plurality of other luminescent devices adjacent to the luminescent device.

2. The light-emitting device according to claim 1, Wherein the first organic compound and the third organic compound are organic compounds comprising a first polycyclic hydrocarbon and a second polycyclic hydrocarbon. Furthermore, the second organic compound and the fourth organic compound are organic compounds containing a third polycyclic hydrocarbon and a polycyclic heterocyclic aromatic ring.

3. The light-emitting device according to claim 2, The first organic compound and the third organic compound are aromatic hydrocarbons.

4. The light-emitting device according to claim 2, The first polycyclic hydrocarbon is the same as the third polycyclic hydrocarbon.

5. The light-emitting device according to claim 4, The first polycyclic hydrocarbon and the third polycyclic hydrocarbon are substituted or unsubstituted anthracene groups.

6. The light-emitting device according to claim 1, The lowest triplet excitation energy level of the first fluorescent luminescent material is higher than the lowest triplet excitation energy level of the first organic compound and the lowest triplet excitation energy level of the second organic compound. Furthermore, the lowest triplet excitation energy level of the second fluorescent luminescent material is higher than the lowest triplet excitation energy level of the third organic compound and the lowest triplet excitation energy level of the fourth organic compound.

7. The light-emitting device according to any one of claims 1 to 6, The first organic compound and one or both of the second organic compound and one or both of the third organic compound and the fourth organic compound are deuterated organic compounds.

8. The light-emitting device according to claim 1, The intermediate layer contains a fifth organic compound with a phenanthroline skeleton and a metal element.

9. The light-emitting device according to claim 1, The second electron transport layer contains a sixth organic compound having a triazine skeleton.

10. A display device comprising a light-emitting device A and a light-emitting device B, in, The light-emitting device A is adjacent to the light-emitting device B. The light-emitting device A includes: First electrode A; Second electrode A; Intermediate layer A; First luminescent layer A; Second light-emitting layer A; The first electron transport layer; and Second electron transport layer A, The intermediate layer A is located between the first electrode A and the second electrode A. The first light-emitting layer A is located between the first electrode A and the intermediate layer A. The second light-emitting layer A is located between the intermediate layer A and the second electrode A. The first electron transport layer A is located between the first light-emitting layer A and the intermediate layer A. The second electron transport layer A is located between the second light-emitting layer A and the second electrode A. The light-emitting device B includes: First electrode B; Second electrode B; Intermediate layer B; First luminescent layer B; Second light-emitting layer B; First electron transport layer B; and Second electron transport layer B, The intermediate layer B is located between the first electrode B and the second electrode B. The first light-emitting layer B is located between the first electrode B and the intermediate layer B. The second light-emitting layer B is located between the intermediate layer B and the second electrode B. The first electron transport layer B is located between the first light-emitting layer B and the intermediate layer B. The second electron transport layer B is located between the second light-emitting layer B and the second electrode B. The second electron transport layer A and the second electron transport layer B are made of the same material. The first luminescent layer A comprises a first fluorescent luminescent substance, a first organic compound, and a second organic compound. The second luminescent layer A comprises a second fluorescent luminescent material, a third organic compound, and a fourth organic compound. The first luminescent layer B contains a third luminescent center material. The second luminescent layer B contains a fourth luminescent center material. The difference between the maximum peak wavelength in the emission spectrum of the first fluorescent luminescent material and the maximum peak wavelength in the emission spectrum of the second fluorescent luminescent material is less than 30 nm. The difference between the maximum peak wavelength in the emission spectrum of the third luminescent center material and the maximum peak wavelength in the emission spectrum of the fourth luminescent center material is less than 30 nm. Furthermore, the first light-emitting layer A and the first light-emitting layer B, and the second light-emitting layer A and the second light-emitting layer B are light-emitting layers that emit light in different hues.

11. The display device according to claim 10, The first light-emitting layer B further comprises an 11th organic compound and a 12th organic compound. Furthermore, the second luminescent layer B also contains a 13th organic compound and a 14th organic compound.

12. A display device, comprising: The first light-emitting device that emits light in the first hue; A second light-emitting device that emits light in a second hue; as well as A third-light-emitting device that emits light in a third hue. The first light-emitting device, the second light-emitting device, and the third light-emitting device all include an intermediate layer and multiple light-emitting layers. The intermediate layer is located between the plurality of light-emitting layers. Each of the plurality of light-emitting layers in the first to the third light-emitting devices comprises a light-emitting central material and a plurality of host materials. In the first to the third light-emitting devices, the light-emitting center material contained in the plurality of light-emitting layers of a single light-emitting device is the same organic compound. Furthermore, the light-emitting layer of the third light-emitting device contains a light-emitting center material that is a fluorescent light-emitting material.

13. A display device, comprising: First light-emitting device; Second light-emitting device; as well as Third light-emitting device, The first light-emitting device includes, in sequence, a first light-emitting layer a, an intermediate layer a, and a second light-emitting layer a. The second light-emitting device comprises, in sequence, a first light-emitting layer b, an intermediate layer b, and a second light-emitting layer b. The third light-emitting device comprises, in sequence, a first light-emitting layer c, an intermediate layer c, and a second light-emitting layer c. The first luminescent layer and the second luminescent layer comprise a luminescent center substance a, a first luminescent organic compound, and a second luminescent organic compound. The first b luminescent layer and the second b luminescent layer comprise luminescent center substance b, an 11b organic compound, and a 12b organic compound. The first c luminescent layer and the second c luminescent layer comprise luminescent center material c, a 15 c organic compound, and a 16 c organic compound. The light-emitting center substances a to c are substances that emit light in different hues. Furthermore, the light-emitting center substance a is a fluorescent light-emitting substance.

Images