Light-emitting devices, electronic equipment, light-emitting devices, and lighting devices

Abstract

To provide a novel light-emitting device, or to provide a light-emitting device with good light-emitting efficiency Alternatively, a light-emitting device with a long life is provided. Alternatively, a light-emitting device with a low driving voltage is provided. Provides services. The EL layer is composed of, in order from the anode side, a first layer, a second layer, a third layer, and a light-emitting layer. and a fourth layer, wherein the first layer comprises a first organic compound and a second organic compound. the fourth layer has a seventh organic compound, and the first organic compound is mixed with the second organic compound. The second organic compound has an electron-accepting property, and its HOMO level is -5.7 eV or more. 0.2 eV or less, and the square root of the electric field strength [V / cm] of the seventh organic compound is 600 At a certain time, the electron mobility is 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less A light-emitting device is provided.

Description

[Technical Field]

[0001] One aspect of the present invention is a light-emitting element, a light-emitting device, a display module, and a lighting module. The present invention relates to a display device, a light-emitting device, an electronic device, and a lighting device. The technical field of one embodiment of the invention disclosed in the present specification and the like is not limited to the following: Alternatively, one aspect of the present invention relates to a process, a machine, , manufacture, or composition of matter Therefore, the technical field of one embodiment of the present invention disclosed in this specification more specifically includes: Semiconductor device, display device, liquid crystal display device, light-emitting device, lighting device, power storage device, memory device, imaging device Examples include devices, methods for driving them, and methods for manufacturing them. . [Background technology]

[0002] Electroluminescence (EL) using organic compounds Light-emitting devices (organic EL elements) that utilize these luminescence are being put to practical use. The basic structure of the device is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material. When a voltage is applied to this element, carriers are injected and the recombination of these carriers occurs. By utilizing the energy, light can be emitted from the light-emitting material.

[0003] Since such light-emitting devices are self-luminous, when they are used as pixels in a display, It has advantages such as high visibility and no need for backlighting compared to flat panel displays. The light-emitting device is suitable for use as a display element. Another major advantage is that it can be manufactured to be thin and lightweight. It is one of the signs.

[0004] In addition, these light-emitting devices can be fabricated with a continuous two-dimensional light-emitting layer. This is a point light source, such as an incandescent bulb or LED, and This is a feature that is difficult to obtain with linear light sources such as fluorescent lamps, so it is used as a surface light source that can be applied to lighting, etc. It is also highly useful as a tool.

[0005] Displays and lighting devices using such light-emitting devices are suitable for use in a variety of electronic devices. However, research and development is being conducted to find light-emitting devices with better efficiency and life span. There are.

[0006] In Patent Document 1, a first hole injection layer is provided between a first hole transport layer in contact with the hole injection layer and a light emitting layer. Hole transport properties with a HOMO level between that of the interlayer and that of the host material A configuration for applying the material is disclosed.

[0007] The properties of light-emitting devices have improved dramatically, but many other properties, including efficiency and durability, remain. It must be said that this is still insufficient to meet the high level of demands on the environment. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2011 / 065136 Brochure Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above, an object of one embodiment of the present invention is to provide a novel light-emitting device. The object of the present invention is to provide a light-emitting device having good luminous efficiency or a long life. The present invention aims to provide a light-emitting device with a low driving voltage. The purpose is to:

[0010] In another embodiment of the present invention, a light-emitting device, an electronic device, and a display device each having high reliability are provided. Another object of the present invention is to provide a light-emitting device with low power consumption. The present invention aims to provide a device, an electronic device, and a display device.

[0011] The present invention is intended to solve any one of the above problems. [Means for solving the problem]

[0012] One aspect of the present invention is a light-emitting diode (LED) having an anode, a cathode, and an EL layer located between the anode and the cathode. In a light-emitting device in which the EL layer has a light-emitting layer, a constant current is applied to the light-emitting device. A light-emitting device that has a maximum value on a degradation curve that represents the change in luminance of light emitted when water is passed through it. is.

[0013] Alternatively, another aspect of the present invention is a device comprising an anode, a cathode, and a cathode-like electrode located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer is composed of a first layer and a second layer in this order from the anode side. The first layer is in contact with the anode, and the third layer is in contact with the light-emitting layer. the first layer has a first organic compound and a second organic compound, and the second layer has a the third layer comprises a fourth organic compound, and the light-emitting layer comprises a fifth organic compound. the fourth layer has a seventh organic compound, and the first layer has a sixth organic compound; The first organic compound is an organic compound that exhibits electron accepting properties to the second organic compound, The fifth organic compound is a luminescent center substance, and the HOMO level of the second organic compound is -5. 7 eV or more and -5.2 eV or less, and the average electric field strength [V / cm] of the seventh organic compound When the square root is 600, the electron mobility is 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, and the change in luminance of light emitted when a constant current is passed through the light-emitting device The light-emitting device has a maximum value on the degradation curve expressed by

[0014] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a the fifth organic compound is an organic compound that exhibits electron accepting properties to the second organic compound, and the fifth organic compound is an organic compound that exhibits luminescence The HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or more. or less, and the difference in HOMO level between the third organic compound and the second organic compound is 0. 2 eV or less, and the HOMO level of the third organic compound is H The square root of the electric field strength [V / cm] of the seventh organic compound is equal to or deeper than the OMO level. 600, the electron mobility is 1×10 -7cm 2 / Vs or more 5×10 -5 cm 2 / Vs is expressed as the change in luminance of light emitted when a constant current is passed through the light-emitting device. The degradation curve of the light-emitting device has a maximum value.

[0015] Another embodiment of the present invention is a light-emitting device having the above structure, wherein the deterioration curve is a light-emitting device having a portion where the light emission is greater than 100%.

[0016] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a the fifth organic compound is an organic compound that exhibits electron accepting properties to the second organic compound, and the fifth organic compound is an organic compound that exhibits luminescence The HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or more. or less, and the difference in HOMO level between the third organic compound and the second organic compound is 0. 2 eV or less, and the HOMO level of the third organic compound is H The square root of the electric field strength [V / cm] of the seventh organic compound is equal to or deeper than the OMO level. 600, the electron mobility is 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs A light emitting device comprising:

[0017] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a the fifth organic compound is an organic compound that exhibits electron accepting properties to the second organic compound, and the fifth organic compound is an organic compound that exhibits luminescence The HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or more. the HOMO level of the third organic compound is equal to or lower than the HOMO level of the second organic compound. the same or deeper than the HOMO level of the third organic compound and the second organic compound, the difference between the LUMO levels of the sixth organic compound and the seventh organic compound is 0.2 eV or less, the LUMO level of the seventh organic compound is shallower than the LUMO level of the sixth organic compound, The light-emitting device has a difference in LUMO levels of 0.1 eV or more and 0.3 eV or less.

[0018] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a the fifth organic compound is an organic compound that exhibits electron accepting properties to the second organic compound, and the fifth organic compound is an organic compound that exhibits luminescence The HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or more. the HOMO level of the third organic compound is equal to or lower than the HOMO level of the second organic compound. the same or deeper than the HOMO level of the third organic compound and the second organic compound, the difference between the electron-doping ratios is 0.2 eV or less, and the seventh organic compound is a π-electron-deficient heteroaromatic compound. It is a light-emitting device.

[0019] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a an organic compound that exhibits electron accepting properties to the second organic compound, and the second organic compound is the third organic compound has a first hole transporting skeleton, the third organic compound has a second hole transporting skeleton, The fourth organic compound has a third hole transporting skeleton, and the fifth organic compound has a luminescent center. a HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or less; wherein the first hole transporting skeleton, the second hole transporting skeleton and the third hole transporting skeleton are The functional skeletons are each independently a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, skeleton and anthracene skeleton, and the electric field strength [V / cm] is 600, the electron mobility is 1×10 -7 cm 2 / Vs or more 5×1 0 -5 cm 2 / Vs or less.

[0020] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a an organic compound that exhibits electron accepting properties to the second organic compound, and the second organic compound is the third organic compound has a first hole transporting skeleton, the third organic compound has a second hole transporting skeleton, The fourth organic compound has a third hole transporting skeleton, and the fifth organic compound has a luminescent center. a HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or less; wherein the first hole transporting skeleton, the second hole transporting skeleton and the third hole transporting skeleton are The functional skeletons are each independently a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, a LUMO level of the sixth organic compound is either one of a hydroxyl group and an anthracene group; is shallower than the LUMO level of the seventh organic compound, and the seventh organic compound and the The difference in LUMO level between the organic compound 6 and the device is 0.1 eV or more and 0.3 eV or less. It is.

[0021] Alternatively, another aspect of the present invention is a liquid crystal display device including an anode, a cathode, and an E The EL layer comprises, in order from the anode side, a first layer, a second layer, a third layer, and an emitting layer. a first layer in contact with the anode and a fourth layer; a first organic compound and a second organic compound, the second layer comprising a third organic compound; The third layer contains a fourth organic compound, and the light-emitting layer contains a fifth organic compound and a sixth organic compound. the fourth layer comprises a seventh organic compound, and the first organic compound is a an organic compound that exhibits electron accepting properties to the second organic compound, and the second organic compound is the third organic compound has a first hole transporting skeleton, the third organic compound has a second hole transporting skeleton, The fourth organic compound has a third hole transporting skeleton, and the fifth organic compound has a luminescent center. a HOMO level of the second organic compound is -5.7 eV or more and -5.2 eV or less; wherein the first hole transporting skeleton, the second hole transporting skeleton and the third hole transporting skeleton are The functional skeletons are each independently a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, skeleton or anthracene skeleton, and the seventh organic compound is a π-electron deficient A light-emitting device that is a heteroaromatic compound.

[0022] Alternatively, another aspect of the present invention is a π-electron-deficient heteroaromatic compound according to the above structure. is a quinoxaline skeleton, a benzimidazole skeleton, or a triazine skeleton It is a light-emitting device.

[0023] Alternatively, in the above structure, another embodiment of the present invention is a method for manufacturing a semiconductor device, wherein the sixth organic compound is a hydrocarbon. the HOMO level of the sixth organic compound is an organic compound consisting of only the fourth organic compound; The fourth organic compound and the sixth organic compound are each deeper than the HOMO level of the organic compound. The difference between the HOMO levels of the two light-emitting devices is 0.2 eV or more and 0.4 eV or less.

[0024] Alternatively, in the above structure, another embodiment of the present invention is a compound in which the sixth organic compound is an anthracene compound. the fourth organic compound and the sixth organic compound are organic compounds having a fluorine skeleton and a heterocyclic skeleton, The difference between the HOMO levels of the organic compounds is less than 0.2 eV.

[0025] Alternatively, in the above structure, another embodiment of the present invention is a compound in which the sixth organic compound is an anthracene compound. the fourth organic compound is an organic compound having a naphthalene ring and a heterocyclic ring; It is a light-emitting device that is an organic compound with two carbazole rings bonded together.

[0026] Alternatively, in the above structure, another embodiment of the present invention is a compound in which the sixth organic compound is an anthracene compound. the fourth organic compound is an organic compound having a 3,3'-(naphthalene) skeleton and a heterocyclic skeleton, Light-emitting device, (phthalene-1,4-diyl)bis(9-phenyl-9H-carbazole) It's a chair.

[0027] Alternatively, in the above structure, another embodiment of the present invention is a compound in which the sixth organic compound is an anthracene compound. the second organic compound is an organic compound having a cyclic skeleton and a heterocyclic skeleton, and the HOMO level of the second organic compound is the electric field strength [V / cm ] is 600, the electron mobility of the sixth organic compound is This is a light-emitting device with an electron mobility less than that when the square root of [m] is 600.

[0028] Alternatively, in the above structure, another embodiment of the present invention is a compound having a HOMO approximation of the fourth organic compound. a light-emitting device in which the difference between the HOMO level of the third organic compound and the HOMO level of the second organic compound is 0.2 eV or less; is.

[0029] Alternatively, in the above structure, another embodiment of the present invention is a compound having a HOMO approximation of the fourth organic compound. The light-emitting device has a HOMO level deeper than the HOMO level of the third organic compound.

[0030] Alternatively, another embodiment of the present invention is a compound according to the above structure, wherein the second organic compound is a dibenzo The light-emitting device is an organic compound having a furan skeleton.

[0031] Alternatively, another embodiment of the present invention is a compound having the above structure, wherein the seventh organic compound is quinoxalate. The light-emitting device is an organic compound with a silane skeleton.

[0032] Alternatively, another embodiment of the present invention is a method for manufacturing a semiconductor device according to the present invention, wherein the second organic compound and the third organic compound are mixed. It is a light-emitting device in which the organic compound is the same material.

[0033] Alternatively, in the above-described structure, another embodiment of the present invention is a light-emitting device in which the fifth organic compound is a blue fluorescent material. It is a light-emitting device that uses a material.

[0034] Another aspect of the present invention is a device having the above-described structure, wherein a sensor, an operation button, a speaker, or the like is provided. Or, Mike It is an electronic device having the following.

[0035] Another embodiment of the present invention is a semiconductor device having the above structure, which includes a transistor or a substrate. It is a light-emitting device.

[0036] Another embodiment of the present invention is a lighting device having the above structure and including a housing.

[0037] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. In addition, a connector such as anisotropic conductive film or TCP (Tape) is attached to the light-emitting device. Module with Carrier Package attached, printed on TCP Modules with wiring boards or light-emitting devices with COG (Chip On Glass) s) Modules in which ICs (integrated circuits) are directly mounted using the method include light-emitting devices. Furthermore, lighting fixtures and the like may include a light-emitting device. [Effects of the Invention]

[0038] According to one embodiment of the present invention, a novel light-emitting device can be provided. It is possible to provide a light-emitting device having good luminous efficiency. It is possible.

[0039] In another embodiment of the present invention, a light-emitting device, an electronic device, and a display device each having high reliability are provided. In another embodiment of the present invention, a light-emitting device with low power consumption can be provided. An electronic device and a display device can each be provided.

[0040] The description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. , the specification, drawings, claims, etc., and It is possible to extract other effects from the claims and other descriptions. [Brief explanation of the drawings]

[0041] [Figure 1] FIG. 1 is a schematic diagram of a light-emitting device. [Figure 2] 2(A) and 2(B) are conceptual diagrams of an active matrix light emitting device. [Figure 3] 3(A) and 3(B) are conceptual diagrams of an active matrix light emitting device. [Figure 4] FIG. 4 is a conceptual diagram of an active matrix light emitting device. [Figure 5] 5(A) and 5(B) are conceptual diagrams of a passive matrix light emitting device. [Figure 6] 6(A) and 6(B) are diagrams showing a lighting device. [Figure 7] 7(A), 7(B1), 7(B2) and 7(C) are diagrams showing electronic devices. [Figure 8] 8(A), 8(B) and 8(C) are diagrams showing electronic devices. [Figure 9] FIG. 9 is a diagram illustrating a lighting device. [Figure 10] FIG. 10 is a diagram illustrating a lighting device. [Figure 11] FIG. 11 is a diagram illustrating an in-vehicle display device and an illumination device. [Figure 12] 12(A) and 12(B) are diagrams showing electronic devices. [Figure 13] 13(A), 13(B) and 13(C) are diagrams showing electronic devices. [Figure 14] FIG. 14 shows the luminance-current density characteristics of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. [Figure 15]FIG. 15 shows the current efficiency-luminance characteristics of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. As shown in FIG. [Figure 16] FIG. 16 shows the luminance-voltage characteristics of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. As shown in FIG. [Figure 17] FIG. 17 shows the current-voltage characteristics of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. As shown in FIG. [Figure 18] FIG. 18 shows the external quantum efficiency-luminance characteristics of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. As shown in FIG. [Figure 19] FIG. 19 shows the emission spectra of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. As shown in FIG. [Figure 20] FIG. 20 shows the normalized luminance vs. time change characteristics of light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2. [Figure 21] FIG. 21 shows the luminance-current density characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. As shown in FIG. [Figure 22] FIG. 22 shows the current efficiency-luminance characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. [Figure 23] FIG. 23 shows the luminance-voltage characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. As shown in FIG. [Figure 24] FIG. 24 shows the current-voltage characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. In FIG. [Figure 25] FIG. 25 shows the external quantum efficiency-luminance characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. [Figure 26] FIG. 26 shows the emission spectra of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. In FIG. [Figure 27] FIG. 27 shows the normalized luminance vs. time change characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3. [Figure 28] FIG. 28 shows the luminance-current density characteristics of light-emitting device 7 and light-emitting device 8. [Figure 29] FIG. 29 shows the current efficiency-luminance characteristics of the light-emitting device 7 and the light-emitting device 8. [Figure 30] FIG. 30 shows the luminance-voltage characteristics of the light-emitting device 7 and the light-emitting device 8. As shown in FIG. [Figure 31] FIG. 31 shows the current-voltage characteristics of the light-emitting device 7 and the light-emitting device 8. As shown in FIG. [Figure 32] FIG. 32 shows the external quantum efficiency-luminance characteristics of the light-emitting device 7 and the light-emitting device 8. [Figure 33] FIG. 33 shows the emission spectra of light-emitting device 7 and light-emitting device 8. [Figure 34] FIG. 34 shows the normalized luminance vs. time change characteristics of the light-emitting device 7 and the light-emitting device 8. [Figure 35] FIG. 35 shows the luminance-current density characteristics of the light-emitting device 9. [Figure 36] FIG. 36 shows the current efficiency-luminance characteristics of the light-emitting device 9. [Figure 37] FIG. 37 shows the luminance-voltage characteristics of the light-emitting device 9. [Figure 38] FIG. 38 shows the current-voltage characteristics of the light-emitting device 9. [Figure 39] FIG. 39 shows the external quantum efficiency-luminance characteristics of the light-emitting device 9. [Figure 40] FIG. 40 shows the emission spectrum of the light-emitting device 9. [Figure 41] FIG. 41 shows the normalized luminance vs. time change characteristics of the light-emitting device 9. [Figure 42] FIG. 42 is a diagram showing the structure of an electron-only element. [Figure 43] FIG. 43 shows the current density-voltage characteristics of the electron-only element. [Figure 44] FIG. 44 shows the frequency characteristics of the calculated capacitance C of ZADN:Liq(1:1) at a DC voltage of 7.0V. [Figure 45]FIG. 45 shows the frequency characteristics of −ΔB of ZADN:Liq(1:1) at a DC voltage of 7.0V. [Figure 46] FIG. 46 shows the electric field strength dependence of electron mobility in each organic compound. [Figure 47] FIG. 47 shows the luminance-current density characteristics of the light-emitting device 10. [Figure 48] FIG. 48 shows the current efficiency-luminance characteristics of the light-emitting device 10. [Figure 49] FIG. 49 shows the luminance-voltage characteristics of the light-emitting device 10. [Figure 50] FIG. 50 shows the current-voltage characteristics of the light-emitting device 10. [Figure 51] FIG. 51 shows the external quantum efficiency-luminance characteristics of the light-emitting device 10. [Figure 52] FIG. 52 shows the emission spectrum of the light-emitting device 10. [Figure 53] FIG. 53 shows the normalized luminance vs. time change characteristics of the light-emitting device 10. [Figure 54] FIG. 54 shows the luminance-current density characteristics of the light-emitting device 11. [Figure 55] FIG. 55 shows the current efficiency-luminance characteristics of the light-emitting device 11. [Figure 56] FIG. 56 shows the luminance-voltage characteristics of the light-emitting device 11. [Figure 57] FIG. 57 shows the current-voltage characteristics of the light-emitting device 11. [Figure 58] FIG. 58 shows the external quantum efficiency-luminance characteristics of the light-emitting device 11. [Figure 59] FIG. 59 shows the emission spectrum of the light-emitting device 11. [Figure 60] FIG. 60 shows the normalized luminance vs. time change characteristics of the light-emitting device 11. [Figure 61] FIG. 61 shows the luminance-current density characteristics of the light-emitting device 12. [Figure 62] FIG. 62 shows the current efficiency-luminance characteristics of the light-emitting device 12. [Figure 63] FIG. 63 shows the luminance-voltage characteristics of the light-emitting device 12. [Figure 64] FIG. 64 shows the current-voltage characteristics of the light-emitting device 12. [Figure 65] FIG. 65 shows the external quantum efficiency-luminance characteristics of the light-emitting device 12. [Figure 66] FIG. 66 shows the emission spectrum of light-emitting device 12. [Figure 67] FIG. 67 shows the normalized luminance vs. time change characteristics of the light-emitting device 12. [Figure 68] FIG. 68 shows the luminance-current density characteristics of light-emitting devices 13 to 20. [Figure 69] FIG. 69 shows the current efficiency-luminance characteristics of light-emitting devices 13 to 20. [Figure 70] FIG. 70 shows the luminance-voltage characteristics of light-emitting devices 13 to 20. [Figure 71] FIG. 71 shows the current-voltage characteristics of light-emitting devices 13 to 20. [Figure 72] FIG. 72 shows the external quantum efficiency-luminance characteristics of light-emitting devices 13 to 20. [Figure 73] FIG. 73 shows the emission spectra of light-emitting devices 13 to 20. [Figure 74] FIG. 74 shows the normalized luminance vs. time change characteristics of the light-emitting devices 13 to 20. DETAILED DESCRIPTION OF THE INVENTION

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the above description, and the form and details thereof may be changed without departing from the spirit and scope of the present invention. It will be readily apparent to those skilled in the art that various modifications may be made to the present invention. It should not be construed as being limited to the description of the embodiments.

[0043] (Embodiment 1) FIG. 1A shows a light-emitting device according to one embodiment of the present invention. The device has an anode 101, a cathode 102, and an EL layer 103. The EL layer It has an injection layer 111 , a hole transport layer 112 , a light emitting layer 113 and an electron transport layer 114 .

[0044] In addition to these, the EL layer 103 in FIG. 1(A) also includes an electron injection layer 115. However, the configuration of the light-emitting device is not limited to this. For example, layers having other functions may be included.

[0045] The hole injection layer 111 includes a first organic compound and a second organic compound. The compound is a substance that exhibits electron accepting properties toward the second organic compound. The HOMO level of the substance is relatively deep, between -5.7 eV and -5.2 eV. The second organic compound has a relatively deep HOMO level. This facilitates the injection of holes into the hole transport layer 112.

[0046] The first organic compound has an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group). Among such substances, the second organic compound A substance that exhibits electron-accepting properties can be appropriately selected. Examples of such organic compounds include: For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (Abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano- 1,4,5,8,9,12-Hexaazatriphenylene (abbreviation: HAT-CN), 1,3 ,4,5,7,8-Hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-T CNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octa Fluoro-7H-pyren-2-ylidene)malononitrile, etc. Compounds such as HAT-CN in which electron-withdrawing groups are bonded to fused aromatic rings containing multiple heteroatoms The compound is thermally stable and is therefore preferred. Radialene derivatives containing benzophenone or cyano groups are preferred because of their high electron-accepting properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidenetris[ 4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α ''-1,2,3-Cyclopropanetriylidenetris[2,6-dichloro-3,5-di Fluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''- 1,2,3-Cyclopropanetriylidenetris[2,3,4,5,6-pentafluoro Benzeneacetonitrile], etc.

[0047] The second organic compound is preferably an organic compound having hole transport properties, and The structure is selected from the group consisting of dibenzofuran, dibenzothiophene, and anthracene skeletons. In particular, it is preferable that the compound has a dibenzofuran ring or a dibenzothiophene ring. aromatic monoamines having a naphthalene ring, or aromatic monoamines having a 9- It was an aromatic monoamine in which the fluorenyl group was attached to the amine nitrogen through an arylene group. It is also possible to use the second organic compound as a compound having an N,N-bis(4-biphenyl)amino group. A material having the formula (I) is preferable because it allows a light-emitting device with a long lifetime to be manufactured. Specific examples of the second organic compound include N-(4-biphenyl)-6, N-Diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfA BP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2- d]Furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[a]thiazolinone) [b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1 ,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-bifuran) phenyl)benzo[b]naphtho[1,2-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-biphenyl ThBA1BP, 4-(2-naphthyl)-4',4''-diphenyl Triphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]- 4',4''-Diphenyltriphenylamine (abbreviation: BBAβNBi), 4-(2;1 '-binaphthyl-6-yl)-4',4''-diphenyltriphenylamine (abbreviation: B BAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl ) Triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4' '-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB- 03), 4-(6;2'-binaphthyl-2-yl)-4',4''-diphenyltriphenyl Nylamine (abbreviation: BBA(βN2)B), 4-(2;2'-binaphthyl-7-yl)- 4',4''-Diphenyltriphenylamine (abbreviation: BBA(βN2)B-03), 4 -(1;2'-binaphthyl-4-yl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNαNB), 4-(1;2′-binaphthyl-5-yl)-4′,4″ -Diphenyltriphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl) 4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TP BiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl] -4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-bi (phenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenyl TPBiAβNBi, 4-(1-naphthyl)-4'-phenyltrifluoromethyl Phenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenyl Amine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazo (4-yl)biphenyl-9-yl)triphenylamine (abbreviation: YGTBi1BP ), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris( 1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4 '-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4 ''-Phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl N-[4-(1-naphthyl)phenyl-9H-carbazol-3-yl]phenyl [9H-fluorenyl]-9,9'-spirobi[9H-fluoren]-2-amine (abbreviation: PCBNBSF) , N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H- fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl BB ASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl- 9H-Fluoren-2-yl)-9,9'-spirobi[9H-fluoren]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-furan) Fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-( 1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl] nyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9 -phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4- phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mB PAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl] 4-phenyl-4'-(9-phenyl)triphenylamine (abbreviation: BPAFLBi), (9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)trimethylsilyl Phenylamine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl)amine (9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4 ,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl) )triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl -9,9'-spirobi[9H-fluorenyl-9H-carbazol-3-ylphenyl] N-(1,1'-biphenyl-4-yl)-2-amine (abbreviation: PCBASF) 9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] Examples include [9H-fluoren-2-amine]-9H-fluoren-2-amine (abbreviation: PCBBiF).

[0048] The hole transport layer 112 includes a first hole transport layer 112-1 and a second hole transport layer 112-2. The first hole transport layer 112-1 is located closer to the anode 101 than the second hole transport layer 112-2. The second hole transport layer 112-2 also functions as an electron blocking layer. In some cases, they may take on this role.

[0049] The first hole transport layer 112-1 contains a third organic compound, and the second hole transport layer 112-2 contains a fourth organic compound. It has organic compounds.

[0050] The third organic compound and the fourth organic compound are organic compounds having a hole transporting property. It is preferable that the third organic compound and the fourth organic compound are used as the second organic compound. Organic compounds that can be used in the same way can be used.

[0051] The HOMO level of the second organic compound and the HOMO level of the third organic compound are The HOMO level of the compound is deeper than that of the compound, and the materials are selected so that the difference is 0.2 eV or less. It is preferable that the second organic compound and the third organic compound are the same substance. It is more preferable that the HOMO level of the third organic compound is higher than the HOMO level of the fourth organic compound. In the O level, it is preferable that the HOMO level of the fourth organic compound is deeper. The materials may be selected so that the difference is 0.2 eV or less. The HOMO levels of the organic compounds have the above relationship, allowing for smooth Holes are injected, and an increase in driving voltage and a state of insufficient holes in the light-emitting layer can be prevented.

[0052] It is preferable that each of the second to fourth organic compounds has a hole-transporting skeleton. The hole transporting skeleton is preferably formed by adding an organic compound having a HOMO level that is too shallow. Carbazole skeleton, dibenzofuran skeleton, dibenzothiophene skeleton and anthracene skeleton In addition, the hole transporting skeleton is preferably a material of adjacent layers (for example, the second (organic compound and third organic compound or third organic compound and fourth organic compound) In particular, the hole transporting skeleton is preferably is preferably a dibenzofuran skeleton.

[0053] In addition, materials contained in adjacent layers (for example, a second organic compound and a third organic compound or a If the organic compound (3) and the organic compound (4) are the same material, hole injection becomes smoother. This is a preferable configuration. In particular, when the second organic compound and the third organic compound are the same material, The configuration is preferred.

[0054] The light-emitting layer 113 contains a fifth organic compound and a sixth organic compound. The sixth organic compound is a host material for dispersing the fifth organic compound. It is a fee.

[0055] The luminescent center material may be a fluorescent material, a phosphorescent material, or a thermally activated delayed fluorescence material. The material may be a material exhibiting TADF (Transparent Active Layer Doping) or other light-emitting materials. The light-emitting device of the present invention may be made up of a single layer or a plurality of layers containing different light-emitting materials. In one embodiment, the light-emitting layer 113 is a layer that exhibits fluorescent emission, particularly a layer that exhibits blue fluorescent emission. It can be suitably applied in some cases.

[0056] In the light-emitting layer 113, materials that can be used as fluorescent materials include, for example: Examples include the following: Other fluorescent materials can also be used.

[0057] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine PAP2BPy, 5,6-bis[4'-(10-phenyl-9-anthracene] N, N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl] )phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-biphenyl bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene 9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn ), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-di Phenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazo (4'-(10-phenyl-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation Name: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl N,9-diphenyl-2-anthryltriphenylamine (abbreviation: 2YGAPPA) N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole -3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert- Butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'- (9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA PA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4, 1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2 -anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA) , N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'- Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N', N',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]chryse N-(9,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, 10-Diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3- Amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)] [N,9-diphenyl-9H-carbazol-3-amine (abbreviated as 2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine] :2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N '-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,1 0-Bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-t Triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis (1,1'-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl] N,N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), ,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), Coumarin 54 5T, N,N'-diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12- Bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: B PT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl -4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl- 6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolinyl] {4H-pyran-4-ylidene}propanedinitrile (abbreviated :DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5 ,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N '-Tetrakis(4-methylphenyl)acenaphtho[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[i j]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinite 2-(2-tert-butyl-6-[2-(1,1,7,7 -Tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizidine 4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl }-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{ 2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7- Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H- Pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJ™), N,N'-( Pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d ]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N -(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2 ,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)- 02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]na Futo[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf( IV)-02) and others. In particular, 1,6FLPAPrn and 1,6mMemFLP Condensation reactions represented by pyrene diamine compounds such as APrn and 1,6BnfAPrn-03 Aromatic diamine compounds have high hole trapping properties, and are excellent in luminous efficiency and reliability. preferable.

[0058] In the light-emitting layer 113, when a phosphorescent material is used as the light-emitting center material, Possible materials include, for example:

[0059] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H -1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III ) (abbreviation: Ir(mpptz-dmp)3), tris(5-methyl-3,4-diphenyl -4H-1,2,4-triazolato)iridium(III) (abbreviation: Ir(Mptz)3 ), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2 ,4-triazolato]iridium(III) (abbreviation: Ir(iPrptz-3b)3) Organometallic iridium complexes with 4H-triazole skeletons, such as tris[3-methyl -1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]yl Ir(Mptz1-mp)3, tris(1-methyl-5-fluorouracil), (phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation Organometallic imines with 1H-triazole skeletons, such as Ir(PrPrtZ1-Me)3) Lithium complexes and fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl] iridium(III) (abbreviation: Ir(iPrpmi)3), Tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phena Iridium(III) (abbreviation: Ir(dmpimpt-Me)3) Organometallic iridium complexes with various imidazole structures and bis[2-(4',6'-difluoromethyl)-2-(4-phenyl ... (fluorophenyl)pyridinato-N,C 2’ ]iridium(III) tetrakis(1-pyra 2-(4',6'-difluorophenyl) bis[2-(4',6'-difluorophenyl) benzoate (abbreviation: FIr6) Pyridinato-N,C 2’]iridium(III) picolinate (abbreviation: FIrpic), Bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2 ’} Iridium(III) picolinate (abbreviation: Ir(CF3ppy)2(pic)), Bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]iridium( III) Electron-withdrawing groups such as acetylacetonate (abbreviation: FIr(acac)) Examples of such organometallic iridium complexes include those with phenylpyridine derivatives as ligands. is a compound that exhibits blue phosphorescence and has an emission peak between 440 nm and 520 nm. It is a compound that

[0060] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: Ir(mppm)3), tris(4-t-butyl-6-phenylpyrimidinato)iridium Ir(III) (abbreviation: Ir(tBuppm)3), (acetylacetonato)bis(6-methyl- (4-phenyl-4-pyrimidinato)iridium(III) (abbreviation: Ir(mppm)2( acac)), (acetylacetonato)bis(6-tert-butyl-4-phenylpyridine Iridium(III) (abbreviation: Ir(tBuppm)2(acac)), (A Cetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]yl Ir(nbppm)2(acac) (Ir(nbppm)2(acac)), (acetylacetonate Nato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]i Lithium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonate Nato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: Ir(d and organometallic iridium complexes having a pyrimidine skeleton, such as (ppm)2(acac)). (Acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium (III) (abbreviation: Ir(mppr-Me)2(acac)), (acetylacetonate) Bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: Ir(mppr-iPr)2(acac)) Metal iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium (I II) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato-N,C 2’ ) Iri Ir(ppy)2acac, bis(benzyl) Ir(bz)benzo[h]quinolinatoiridium(III) acetylacetonate (abbreviation: Ir(bz) q) 2(acac)), tris(benzo[h]quinolinato)iridium(III) (abbreviation :Ir(bzq)3), tris(2-phenylquinolinato-N,C 2’ ) Iridium (I II) (abbreviation: Ir(pq)3), bis(2-phenylquinolinato-N,C 2’ ) Iriji Pi such as Ir(III) acetylacetonate (abbreviated as Ir(pq)2(acac)) In addition to organometallic iridium complexes with a lysine skeleton, tris(acetylacetonato)(mono Phenanthroline) terbium(III) (abbreviation: Tb(acac)3(Phen)) These are compounds that mainly exhibit green phosphorescence. The emission peak is in the range of 500 nm to 600 nm. Metal iridium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0061] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinyl] Nato]iridium(III) (abbreviation: Ir(5mdppm)2(dibm)), bis[4 ,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium (III) (abbreviation: Ir(5mdppm)2(dpm)), bis[4,6-di(naphthalene)] (1-phenyl-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Organometallic iridium with a pyrimidine backbone, such as Ir(d1npm)2(dpm) Complexes and (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium Ir(tppr)2(acac)), bis(2,3,5-triphenylphosphine) Nylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: Ir(tpp r) 2(dpm)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl) Ir(Fdpq)2(acac) Organometallic iridium complexes with pyrazine skeletons such as tris(1-phenylisoxid) Norinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(piq)3), bis(1- Phenylisoquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation Organometallic iridium complexes with a pyridine skeleton, such as Ir(piq)2acac In addition, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-pol Platinum complexes such as phyrinplatinum(II) (abbreviated as PtOEP) and tris(1,3-difluorophenyl) (phenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: Eu(DBM)3(Phen)), tris[1-(2-thenoyl)-3,3,3 -trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: These include rare earth metal complexes such as Eu(TTA)3(Phen). It is a compound that exhibits phosphorescence and has an emission peak at 600 nm to 700 nm. In addition, organometallic iridium complexes with a pyrazine skeleton can emit red light with good chromaticity. .

[0062] In addition to the phosphorescent compounds described above, known phosphorescent light-emitting materials may be selected and used. stomach.

[0063] TADF materials include fullerene and its derivatives, acridine and its derivatives, and eosin. Derivatives of magnesium (Mg), zinc (Zn), cadmium, etc. can also be used. (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (P d) and the like. Examples of the metal-containing porphyrin include: For example, the protoporphyrin-tin fluoride complex (SnF2(Pro to IX), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), Hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), Copropor Phyllin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4M e)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), ethiop Porphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin -platinum chloride complex (PtCl2OEP) and the like.

[0064] [ka]

[0065] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenyl)-4-phenyl-4-methyl-4-phenyl ... (phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine ( Abbreviation: PIC-TRZ) and 9-(4,6-diphenyl-1,3,5-triazine-2- yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzT zn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-3-yl] 4,6-diphenyl-1,3,5-triazine (abbreviated as '4,6-diphenyl-1,3,5-triazine- ...') Name: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl ]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4 -(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5- Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-diphenyl Methyl-9H-acridin-10-yl)-9H-xanthen-9-one (Acr XTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl] Sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[a π electrons of clidin-9,9'-anthracen]-10'-one (abbreviation: ACRSA), etc. Heterocyclic compounds having either or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are also used. The heterocyclic compound may be a π-electron rich heteroaromatic ring or a π-electron deficient heteroaromatic ring. Since it has an aromatic ring, it has high electron transporting properties and hole transporting properties, which is preferable. Among the skeletons with a toe-shaped heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyridine skeleton) The arazine skeleton, pyridazine skeleton, and triazine skeleton are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrimidine skeleton, The thienopyrazine skeleton and the benzothienopyrazine skeleton are preferred because they have high electron-accepting properties and good reliability. In addition, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxa The azine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are stable. It is preferable that the polymer has at least one of the skeletons because it has good stability and reliability. The dibenzofuran skeleton is used as the benzophenone skeleton, and the dibenzothiophene skeleton is used as the thiophene skeleton. The pyrrole skeleton is preferably an indole skeleton or a carbazole skeleton. Indolocarbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H-carbazole) A π-electron-rich complex is particularly preferred. A substance in which an aromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is called a π-electron-rich heteroaromatic ring. The electron donating property of the π-electron deficient heteroaromatic ring and the electron accepting property of the π-electron deficient heteroaromatic ring are both increased, and the S1 and T1 levels This is particularly preferred because the energy difference between the two is small, and thermally activated delayed fluorescence can be obtained efficiently. It is preferable that an electron-withdrawing group such as a cyano group is bonded instead of the π-electron-deficient heteroaromatic ring. In addition, the π-electron-rich skeleton may be an aromatic amine skeleton, a phenanthroline skeleton, or the like. Examples of π-electron deficient skeletons include xanthene skeletons, thiazolinone skeletons, and the like. Oxanthene dioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazoline borane skeleton, anthraquinone skeleton, boron-containing skeletons such as phenylborane and boranthrene, benzo Aromatic rings and heteroaromatic rings containing nitrile or cyano groups such as nitrile or cyanobenzene ring, carbonyl skeleton such as benzophenone, phosphine oxide skeleton, sulfone skeleton, etc. In this way, the π-electron deficient heteroaromatic ring and the π-electron rich heteroaromatic ring can be In place of at least one of the above, a π-electron deficient skeleton and a π-electron rich skeleton can be used. Cut.

[0066] [ka]

[0067] TADF materials have a small difference between the S1 and T1 levels, and triple intersystem crossing occurs due to reverse intersystem crossing. The function of converting energy from first excitation energy to singlet excitation energy Therefore, the triplet excitation energy can be converted to a single state by a small amount of thermal energy. It is possible to upconvert to doublet excited energy (reverse intersystem crossing), and efficiently convert the singlet excited state It is possible to generate triplet excitation energy and convert it into luminescence. .

[0068] In addition, exciplexes (exciplexes) that form excited states with two types of substances The difference between the S1 and T1 levels is extremely small, As a TADF material capable of converting triplet excitation energy into singlet excitation energy, It has all the functions.

[0069] As an index of the T1 level, the phosphorescence spectrum observed at low temperatures (for example, from 77 K to 10 K) As for TADF materials, the fluorescent light spectrum has a short wavelength tail. Draw a tangent line to the S1 level, and the energy of the wavelength of the extrapolated line is the S1 level. When a tangent line is drawn at the long side of the tail and the energy of the wavelength of the extrapolated line is taken as the T1 level, The difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less. Even more preferable.

[0070] In addition, when a TADF material is used as the luminescent center material, the S1 level of the host material is It is preferable that the T1 level of the host material is higher than the T1 level of the TADF material. A level higher than 1 is preferred.

[0071] The host material of the light-emitting layer may be a material having electron transport properties, a material having hole transport properties, or a TA Various carrier transport materials such as DF materials can be used.

[0072] As a material having hole transport properties, 4,4'-bis[N-(1-naphthyl)-N-phenyl] N,N'-bis(3-methylphenyl)-N, N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenyl]a 4-phenyl-4'-(9-phenylfluorene)biphenyl (abbreviation: BSPB), -9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9- (phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-fluoren-9-yl Phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine ( PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-chlor PCBBi1BP, 4-(1-naphtho-3-yl)triphenylamine ethyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine( Abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H -carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl thyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]phenyl N-phenyl-N-[4-(9- (phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H- Compounds with an aromatic amine skeleton, such as [fluoren]-2-amine (abbreviation: PCBASF) , 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N- Carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl) 3,3'-bis(9-phenyl- 9H-carbazole (abbreviated as PCCP), and ,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene)(abbreviation Name: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoro

[0123] (9-phenyl-2-olen-9-yl)dibenzothiophene (abbreviation: DBTFLP-III), 4 -[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzyl compounds with a thiophene skeleton, such as dibenzothiophene (abbreviated as DBTFLP-IV); 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation :DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl )phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) Among the above, compounds having an aromatic amine skeleton are Compounds having a carbazole skeleton have good reliability and high hole transport properties. This is also preferable because it contributes to reducing the driving voltage. Organic compounds can also be used.

[0073] Examples of materials having electron transport properties include bis(10-hydroxybenzo[h]quinolinol). Nat)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato) )(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8- Quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl) phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl) phenolato]zinc(II) (abbreviation: ZnBTZ) and other metal complexes, (4-tert-butylphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation :PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl) phenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-te rt-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl) phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5 -benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TP BI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H -benzimidazole (abbreviation: mDBTBIm-II) Heterocyclic compounds and 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f ,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene [f,h]quinoxaline (abbreviated as 2-phenyl-4-yl)biphenyl-3-yl)dibenzo[f,h]quinoxaline mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl 4,6-[(2-yl)-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq) -Bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPn P2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation Heterocyclic compounds with diazine skeletons such as 3,5 -Bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCz PPy), 1,3,5-tri[3-(3-pyridyl)-phenyl]benzene (abbreviation: Tm PyPB) and other heterocyclic compounds having a pyridine skeleton. Heterocyclic compounds with an azine skeleton and heterocyclic compounds with a pyridine skeleton have good reliability. In particular, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton are The electron transport property is high, and this contributes to reducing the driving voltage.

[0074] The TADF materials that can be used as host materials are the same as those listed above. When a TADF material is used as a host material, the The triplet excitation energy is converted to singlet excitation energy by reverse intersystem crossing, and By transferring energy to the luminescent center substance, the luminous efficiency of the light-emitting element can be increased. In this case, the TADF material acts as an energy donor, and the luminescent center acts as an energy absorber. It functions as a receptor.

[0075] This is extremely effective when the luminescent center substance is a fluorescent substance. In order to obtain high luminous efficiency, the S1 level of the TADF material must be higher than the S1 level of the fluorescent material. The T1 level of the TADF material is preferably higher than the S1 level of the fluorescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent material. It is preferable that the level is higher.

[0076] In addition, T that exhibits emission that overlaps with the wavelength of the lowest energy absorption band of the fluorescent substance It is preferable to use an ADF material, which allows the TADF material to be converted into a fluorescent material. This is preferable because the transfer of excitation energy becomes smooth and light emission can be obtained efficiently.

[0077] In addition, singlet excitation energy is efficiently generated from triplet excitation energy by reverse intersystem crossing. For this to occur, it is preferable that carrier recombination occurs in the TADF material. The triplet excitation energy generated in the DF material is transferred to the triplet excitation energy of the fluorescent material. For this purpose, it is preferable that the fluorescent substance has a luminophore ( It is preferable that the compound has a protecting group around the π bond (the skeleton that causes light emission). A substituent having no carbon atoms is preferred, and a saturated hydrocarbon is preferred, specifically a hydrocarbon having 3 to 10 carbon atoms. The alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, A trialkylsilyl group having 3 to 10 protecting groups is preferred, and a group having a plurality of protecting groups is more preferred. Substituents without π bonds have poor carrier transport function, and therefore, The distance between the TADF material and the luminophores of the fluorescent material can be reduced without significantly affecting carrier recombination. Here, the luminophore is the molecule that causes light emission in a fluorescent substance. The luminophore preferably has a skeleton with a π bond and contains an aromatic ring. Preferably, the aromatic ring has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of the heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, and a phenanthren skeleton. Examples of the hydroxyazine skeleton include naphthalene skeleton and anthracene skeleton. skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetracene skeleton, pyrene skeleton perylene skeleton, coumarin skeleton, quinacridone skeleton, naphthobisbenzofuran skeleton Fluorescent materials that emit light with high fluorescence quantum yields are preferred.

[0078] When a fluorescent substance is used as the luminescent center substance, the host material is preferably a compound having an anthracene skeleton. A material having an anthracene skeleton is preferably used as a host material for a fluorescent material. When used as a phosphor, it is possible to realize a light-emitting layer having good luminous efficiency and durability. As a material having an anthracene skeleton, a diphenylanthracene skeleton is used. In particular, substances with a 9,10-diphenylanthracene skeleton are chemically stable. In addition, when the host material has a carbazole skeleton, the hole injection / transport property is high. However, a benzocarbazole skeleton in which a benzene ring is further condensed to a carbazole is preferred. When it contains a saccharin, the HOMO is shallower than that of carbazole by about 0.1 eV, making it easier for holes to enter. In particular, when the host material contains a dibenzocarbazole skeleton, The HOMO is about 0.1 eV shallower than that of rubazole, making it easier for holes to enter. It is also suitable because it has excellent transportability and high heat resistance. Among these, 9,10-diphenylanthracene skeleton and carbazole skeleton (and It is a substance that simultaneously has a benzocarbazole skeleton or a dibenzocarbazole skeleton. From the viewpoint of the hole injection and transport properties, a benzofluorene skeleton was used instead of a carbazole skeleton. A fluorene skeleton or a dibenzofluorene skeleton may also be used. Examples of such substances include 9-fluorene, Phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazo PCzPA, 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9 H-Carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracene 7-[4-(10-phenyl)phenyl]-9H-carbazole (abbreviation: CzPA), -9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgD BCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzophenone Zo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10 -{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}an Thracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl) phenyl]anthracene (abbreviation: αN-βNPAnth), etc. In particular, CzP A, cgDBCzPA, 2mBnfPPA, and PCzPA show very good properties. This is the preferred choice.

[0079] The host material may be a mixture of a plurality of substances. When used, a material having an electron transporting property and a material having a hole transporting property may be mixed. It is preferable to mix a material having an electron transport property with a material having a hole transport property. Therefore, the transport property of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. The weight ratio of the content of the material having hole transport properties to the content of the material having electron transport properties is The ratio of the material having hole transport properties to the material having electron transport properties may be 1:19 to 19:1.

[0080] A phosphorescent material can be used as part of the mixed material. When a fluorescent substance is used as the luminescent center material, the luminescent substance is It can be used as an energy donor that provides

[0081] Furthermore, these mixed materials may form an exciplex. The exciplex is formed to emit light that overlaps with the wavelength of the lowest energy absorption band of By selecting such a combination, energy transfer becomes smooth and light emission can be obtained efficiently. In addition, the use of this configuration is also preferable because the driving voltage is reduced.

[0082] At least one of the materials forming the exciplex may be a phosphorescent material. By doing so, triplet excitation energy is efficiently converted to singlet excitation energy by reverse intersystem crossing. can be converted to

[0083] As a combination of materials that efficiently form exciplexes, HO It is preferable that the MO level is equal to or higher than the HOMO level of the material having electron transport properties. When the LUMO level of the material having electron transport properties is higher than the LUMO level of the material having electron transport properties, It is preferable that the LUMO level and the HOMO level of the material are determined by cyclic voltammetry. From the electrochemical properties (reduction potential and oxidation potential) of the material measured by CV measurement It can be derived.

[0084] The formation of an exciplex is determined by, for example, the emission spectrum of a material having hole transport properties, the emission spectrum of a material having electron transport properties, The emission spectrum of the material having the above structure and the emission spectrum of the mixed film of these materials are shown in Fig. In comparison, the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material ( This can be confirmed by observing the phenomenon of a new peak on the long wavelength side. Alternatively, transient photoluminescence (PL) of materials with hole transport properties and electron transport properties can be observed. The transient PL of the materials with the same properties and the transient PL of the mixed film of these materials were compared. The transient PL lifetime of the film has a longer-lived component than the transient PL lifetime of each material, or a delayed component. This can be confirmed by observing the difference in transient response, such as the percentage of In addition, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, the transient EL of a material with hole transport properties and the transient E of a material with electron transport properties are By comparing the transient EL of the L and the mixed films and observing the difference in the transient response, The formation of exciplexes can be confirmed.

[0085] Here, the sixth organic compound is composed only of hydrocarbons such as the above αN-βNPAnth. If the organic compounds are the same, the HOMO level of the fourth organic compound and the HOMO level of the sixth organic compound are In the O level, the HOMO level of the sixth organic compound is deeper, and the difference is 0.2 eV or more, or 0.4 eV or more. It is preferable that the barrier is 100 eV or less, since the transportability of holes is moderately hindered by the barrier.

[0086] In addition, the sixth organic compound has an anthracene skeleton such as the above-mentioned cgDBCzPA or CzPA. When the organic compound is an organic compound having a heterocyclic skeleton, the fourth organic compound and the sixth organic compound The difference in HOMO levels is less than 0.2 eV, so that holes are not blocked by the injection barrier. In this case, it is preferable that the fourth organic compound has two carbon atoms in the naphthalene ring. It is preferably an organic compound having a benzol ring bonded thereto, and typically, 3,3'-(naphthalene) Examples of suitable amines include methacrylate (methacrylate-1,4-diyl)bis(9-phenyl-9H-carbazole). Cut.

[0087] In addition, the sixth organic compound has an anthracene skeleton such as the above-mentioned cgDBCzPA or CzPA. If the organic compound has a heterocyclic skeleton, the HOMO level of the second organic compound is -5. A value of 4 eV or more and −5.7 eV or less is preferable because deterioration can be further suppressed.

[0088] The electron transport layer 114 contains a seventh organic compound. The seventh organic compound has electron transport properties. The organic compound is preferably a π-electron deficient heteroaromatic compound. In particular, a compound having a quinoxaline skeleton, a benzimidazole skeleton, or a triazine skeleton As the organic compound having an electron transporting property, it is preferable to use the above-mentioned host material. Usable organic compounds having electron transport properties or host materials for the fluorescent emitting substances The organic compounds listed above as usable as the additive can be used.

[0089] The seventh organic compound has an electron mobility of 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 In addition, it is preferable that the LUMO level of the sixth organic compound is 1 / Vs or less. When comparing the LUMO levels of the seven organic compounds, the LUMO level of the sixth organic compound is shallower. It is more preferable that the difference is 0.1 eV or more and 0.3 eV or less. Furthermore, the electron transfer of the seventh organic compound when the square root of the electric field strength [V / cm] is 600 The electron mobility of the sixth organic compound is higher than that of the sixth organic compound when the square root of the electric field strength [V / cm] is 600. In the former case, the electron transport property in the electron transport layer is reduced. In the latter case, the amount of electrons injected into the light-emitting layer is controlled by the difference in LUMO level. This can prevent the light-emitting layer from becoming an electron-excess state.

[0090] When the light-emitting layer becomes electron-excessive, the light-emitting region is limited to a certain area, and the load on that area increases. In addition, electrons cannot recombine and pass through the light-emitting layer, which accelerates degradation. In one embodiment of the present invention, the above-mentioned state is prevented. This prevents the occurrence of light emitting diodes, thereby providing a light emitting device with a long life and good light emitting efficiency.

[0091] In addition, in a light-emitting device having such a configuration, a driving test under a constant current density condition In the brightness degradation curve obtained by The degradation behavior of the present invention is that it increases a little and then deteriorates again. In one embodiment, the light-emitting device has a maximum value in the degradation curve. This results in a light-emitting device with a long life. When the derivative of this degradation curve is taken, the value is In other words, there is a part where the differential of the deterioration curve is 0. The light-emitting device according to one embodiment of the present invention can be a light-emitting device with an extremely long life.

[0092] A light-emitting device according to one embodiment of the present invention having the above structure has a long lifetime. It is possible to do so.

[0093] (Embodiment 2) Next, examples of the detailed structure and materials of the light-emitting device will be described. As described above, the light-emitting device is made up of a plurality of layers between a pair of electrodes, an anode 101 and a cathode 102. The EL layer 103 has a hole injection layer 111, a second The first hole transport layer 112-1, the second hole transport layer 112-2, the light-emitting layer 113, and the electron transport layer layer 114.

[0094] The other layers included in the EL layer 103 are not particularly limited, and may include a hole injection layer, a hole transport layer, and the like. layer, electron transport layer, electron injection layer, carrier blocking layer, exciton blocking layer, charge generation layer, etc. , various layer structures can be applied.

[0095] The anode 101 is made of a metal, alloy, or conductive compound having a large work function (specifically, 4.0 eV or more). It is preferable to form the film using a material such as a material containing fluorine, a compound ... Indium tin oxide (ITO), silicon or Indium oxide-tin oxide, indium oxide-zinc oxide, oxide containing silicon oxide Examples include indium oxide containing tungsten and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but they can also be formed by methods such as sol-gel deposition. As an example of the manufacturing method, indium oxide-zinc oxide Sputtering was performed using a target containing 1 to 20 wt% zinc oxide added to indium oxide. Also, there are methods for forming the film by the ring method. Indium oxide (IWZO) is a material that is made by mixing tungsten oxide with indium oxide at a ratio of 0.5 to 5. % by weight and zinc oxide 0.1-1 wt% by sputtering. Other materials include gold (Au), platinum (Pt), nickel (Ni), and titanium. W, chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co) , copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride), etc. Graphene can also be used. Representative materials for forming the electrode have been listed above. In one embodiment of the present invention, 11, an organic compound having hole transport properties and a substance showing electron accepting properties to the organic compound Since a composite material containing the above is used, the electrode material can be selected regardless of the work function.

[0096] In this embodiment, the stacked structure of the EL layer 103 is as shown in FIG. Injection layer 111, first hole transport layer 112-1, second hole transport layer 112-2, light emitting layer 11 3. A structure having an electron injection layer 115 in addition to the electron transport layer 114, and as shown in FIG. 1(B), As shown, the hole injection layer 111, the first hole transport layer 112-1, the second hole transport layer 112-2, Two types of structures: a structure having a light-emitting layer 113, an electron transport layer 114, and a charge generation layer 116 The materials constituting each layer are specifically described below.

[0097] Hole injection layer 111, hole transport layer 112 (hole transport layer 112-1, hole transport layer 112-2) The light-emitting layer 113 and the electron transport layer 114 have been described in detail in the first embodiment, so The corresponding description is omitted. Please refer to the description in the first embodiment.

[0098] Between the electron transport layer 114 and the cathode 102, an electron injection layer 115 containing lithium fluoride (Li Alkali such as iF, cesium fluoride (CsF), calcium fluoride (CaF2), etc. A layer containing a metal, an alkaline earth metal, or a compound thereof may be provided. 5 is a layer made of a substance having an electron transporting property, in which an alkali metal or alkaline earth metal or A material containing these compounds or an electride may also be used. For example, a substance in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum is Examples include:

[0099] In addition, a charge generation layer 114 is formed between the electron transport layer 114 and the cathode 102 instead of the electron injection layer 115. The charge generation layer 116 may be formed by applying a potential. A layer capable of injecting holes into a layer in contact with the cathode side of the layer and electrons into a layer in contact with the anode side of the layer. The charge generation layer 116 includes at least a P-type layer 117. The hole injection layer 111 may be formed using the composite material mentioned above as a material that can be used to form the hole injection layer 111. It is preferable that the P-type layer 117 is formed of the above-mentioned material constituting the composite material. It may be configured by laminating a film containing a substance exhibiting electron accepting properties and a film containing a hole transport material. By applying a potential to the mold layer 117, electrons are transported to the electron transport layer 114, and the cathode 1 Holes are injected into 02, causing the light-emitting device to operate.

[0100] The charge generation layer 116 includes an electron relay layer 118 and an electron injection buffer layer 119 in addition to the P-type layer 117. Preferably, one or both of layers 119 are provided.

[0101] The electron relay layer 118 contains at least a substance having electron transport properties, and the electron injection buffer layer 1 The electrons are transferred smoothly by preventing the interaction between the P-type layer 117 and the P-type layer 119. The LUMO level of the substance having electron transport properties contained in the relay layer 118 is The LUMO level of the electron-accepting material in the electron transport layer 114 is It is preferable that the LUMO level of the electron relay layer 118 is between the LUMO level of the material contained in the layer. The specific energy level of the LUMO level in the electron transport material used in It is preferable that the potential is set to −5.0 eV or more, and more preferably to −5.0 eV or more and −3.0 eV or less. The electron relay layer 118 may be made of a phthalocyanine-based material having electron transport properties. It is preferred to use a metal complex having a metal-oxygen bond and an aromatic ligand.

[0102] The electron injection buffer layer 119 contains an alkali metal, an alkaline earth metal, a rare earth metal, and These compounds (alkali metal compounds (oxides such as lithium oxide, halides, lithium carbonate) Alkaline earth metal compounds (including carbonates such as titanium and cesium carbonate), alkaline earth metal compounds (oxides, halogens compounds of rare earth metals (including oxides, halides, carbonates) or compounds of rare earth metals (including oxides, halides, carbonates) It is possible to use a material with high electron injection properties, such as SiO 2 .

[0103] The electron injection buffer layer 119 contains a material having an electron transporting property and an electron donating material. When formed, the electron donor material may be an alkali metal, an alkaline earth metal, a rare earth metal, Metals and their compounds (alkali metal compounds (oxides such as lithium oxide, halogens oxides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (oxides compounds of rare earth metals (including oxides, halides, carbonates) or rare earth metal compounds (including oxides, halides , including carbonates), as well as tetrathianaphthacene (abbreviated as TTN), nickelocene, deca Organic compounds such as methylnickelocene can also be used. The material is the same as that of the electron transport layer 114 described above. It is possible.

[0104] The material for forming the cathode 102 is gold, which has a small work function (specifically, 3.8 eV or less). Metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) and cesium (Cs). , and elements such as magnesium (Mg), calcium (Ca), and strontium (Sr) Elements belonging to Group 1 or 2 of the periodic table and alloys containing these elements (MgAg, AlL i), europium (Eu), ytterbium (Yb), and other rare earth metals, and However, an electron injection layer may be provided between the cathode 102 and the electron transport layer. By providing this, regardless of the magnitude of the work function, Al, Ag, ITO, silicon or oxide Various conductive materials such as silicon dioxide-containing indium oxide-tin oxide can be used as the cathode 102. You can be there. These conductive materials can be applied by dry methods such as vacuum deposition and sputtering, inkjet printing, It is possible to form the film using a spin coating method, etc. Also, it is possible to form the film using a wet sol-gel method. Alternatively, the metal layer may be formed by a wet method using a paste of a metal material.

[0105] The EL layer 103 can be formed by various methods, including dry and wet methods. For example, vacuum deposition, gravure printing, offset printing, screen printing, etc. A printing method, an ink jet method, a spin coating method, or the like may also be used.

[0106] Furthermore, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0107] The structure of the layer provided between the anode 101 and the cathode 102 is not limited to the above. However, the proximity of the light-emitting region to the metals used in the electrodes and carrier injection layer In order to suppress quenching caused by the hole It is preferable to provide a light-emitting region where the electrons recombine with the cathode.

[0108] Furthermore, recombination in the hole transport layer or electron transport layer in contact with the light-emitting layer 113, particularly in the light-emitting layer 113 The carrier transport layer close to the region suppresses energy transfer from excitons generated in the light-emitting layer. Therefore, the band gap is determined by the luminescent material that constitutes the luminescent layer or the luminescent material contained in the luminescent layer. It is preferable that the material be made of a substance having a band gap larger than the band gap of the material. I wish.

[0109] Next, we developed a light-emitting device (a stacked element, a tandem element) that has a structure in which multiple light-emitting units are stacked. The embodiment of the light-emitting device (also referred to as a "light-emitting device") will be described with reference to FIG. A light-emitting device has multiple light-emitting units between the electrode and the cathode. The EL layer 103 has a structure similar to that of the EL layer 103 shown in FIG. The light emitting device shown in FIG. 1(A) or The light-emitting device shown in FIG. 1(B) is a light-emitting device having one light-emitting unit. It can be said that.

[0110] In FIG. 1C, a first light-emitting unit 511 and a second light-emitting unit 512 are disposed between the anode 501 and the cathode 502. The second light-emitting unit 512 is stacked, and the first light-emitting unit 511 and the second light-emitting unit A charge generating layer 513 is provided between the anode 501 and the cathode 502. These correspond to the anode 101 and the cathode 102 in FIG. 1(A), respectively, and are described in the explanation of FIG. 1(A). The same as that used for the first light-emitting unit 511 and the second light-emitting unit 512 can be applied. The optical units 512 may be of the same or different construction.

[0111] When a voltage is applied between the anode 501 and the cathode 502, the charge generating layer 513 generates a light emitting The electron-injecting unit has the function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit. In 1(C), when a voltage is applied so that the anode potential is higher than the cathode potential, In this case, the charge generating layer 513 injects electrons into the first light-emitting unit 511 and Any material capable of injecting holes into the gate 512 may be used.

[0112] The charge generation layer 513 is formed to have the same structure as the charge generation layer 116 described in FIG. 1B. The composite material of an organic compound and a metal oxide has the properties of carrier injection, carrier transport, and the like. It has excellent electrical properties, making it possible to achieve low voltage and low current driving. When the anode side of the unit is in contact with the charge generating layer 513, the charge generating layer 513 is the light emitting unit. Since it can also function as a hole injection layer for the light-emitting unit, the light-emitting unit does not need to have a hole injection layer. Both are good.

[0113] In addition, when the electron injection buffer layer 119 is provided in the charge generation layer 513, the electron injection buffer Since the electron injection layer 119 plays the role of an electron injection layer in the light-emitting unit on the anode side, the light-emitting layer The unit does not necessarily need to have an electron injection layer.

[0114] Although the light-emitting device having two light-emitting units has been described in FIG. 1C, the light-emitting device having three or more light-emitting units may be used. The same can be applied to a light-emitting device in which the above light-emitting units are stacked. As in the light-emitting device according to the present embodiment, a plurality of light-emitting units are electrically connected between a pair of electrodes. By separating the layers with the generation layer 513, high brightness light emission is possible while keeping the current density low. This allows for an even longer-life element. The device can be realized.

[0115] In addition, by making the light color of each light-emitting unit different, the light-emitting device as a whole can be For example, a light-emitting device having two light-emitting units can be used to obtain light of a desired color. In this device, the first light-emitting unit emits red and green light, and the second light-emitting unit emits blue light. By obtaining a color, it is possible to obtain a light-emitting device that emits white light as a whole. In a light-emitting device having three light-emitting units, the first light-emitting unit A blue light-emitting color, a second light-emitting unit having a spectrum ranging from green to red, and a third light-emitting unit having a spectrum ranging from green to red. By obtaining blue light from the light-emitting unit, the load on the blue light-emitting unit is distributed, It is possible to obtain a light-emitting device with a long life.

[0116] In addition, the EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and Each layer such as the charge generating layer and the electrodes can be formed by, for example, a vapor deposition method (including a vacuum deposition method), a droplet discharge method (including an ink jet method), or the like. It can be formed by using methods such as ink jet printing, coating, and gravure printing. They can be used in a variety of applications, including low molecular weight materials, medium molecular weight materials (including oligomers and dendrimers), and or polymeric material.

[0117] (Embodiment 3) In this embodiment, light emission using the light-emitting device described in the first and second embodiments is The device will now be described.

[0118] In this embodiment, a light-emitting device described in Embodiments 1 and 2 is used to manufacture a The light-emitting device will be described with reference to FIG. 2. Note that FIG. 2(A) shows the light-emitting device. 2(B) is a cross-sectional view taken along lines AB and CD in FIG. 2(A). The device includes a drive circuit section (source) shown by a dotted line that controls the light emission of the light emitting device. The pixel section 602 includes a gate line driving circuit section (gate line driving circuit) 601, a pixel section 602, and a driving circuit section (gate line driving circuit) 603. Further, 604 is a sealing substrate, 605 is a sealing material, and the inside surrounded by the sealing material 605 has become space 607.

[0119] The lead wiring 608 is connected to the source line driver circuit 601 and the gate line driver circuit 603. The wiring is for transmitting signals, and the FPC (flexible printed circuit board) is the external input terminal. Video signal, clock signal, start signal, reset signal, etc. from the input circuit 609 Although only the FPC is shown here, this FPC has a printed wiring board. The light emitting device in this specification may be a light emitting device. This includes not only the device itself but also the state in which an FPC or PWB is attached to it. do.

[0120] Next, the cross-sectional structure will be described with reference to FIG. A source line driver circuit 601 and a pixel portion are formed. , one pixel in the pixel section 602 is shown.

[0121] The element substrate 610 may be a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like. FRP (Fiber Reinforced Plastics), PVF (Polyvinyl It is made using a plastic substrate made of, for example, fluoride, polyester, or acrylic. That's fine.

[0122] The structure of the transistors used in the pixels and driver circuits is not particularly limited. The transistor may be a top-type transistor or a staggered type transistor. The transistor may be a gate type transistor or a bottom gate type transistor. The semiconductor material is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and nitride. Gallium or the like can be used. Alternatively, in-type metal oxides such as In-Ga-Zn-based metal oxides can be used. An oxide semiconductor containing at least one of tungsten, gallium, and zinc may be used.

[0123] The crystallinity of the semiconductor material used in the transistor is not particularly limited. A semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal semiconductor, or a semiconductor having a partially crystalline region) When a semiconductor having crystallinity is used, the transistor This is preferable because it can suppress deterioration of the star characteristics.

[0124] Here, in addition to the transistors provided in the pixels and the driver circuits, It is preferable to use an oxide semiconductor for a semiconductor device such as a transistor. In particular, it is preferable to use an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor with a wider band gap than silicon, the off-state of the transistor can be This can reduce the current in the

[0125] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). In addition, In-M-Zn oxides (where M is Al, Ti, Ga, Ge, Y, Zr, Sn, It is preferable that the oxide semiconductor contains an oxide represented by the formula (metal such as La, Ce or Hf). More preferable.

[0126] In particular, the semiconductor layer has a plurality of crystal portions, and the c-axes of the crystal portions are aligned with the surface on which the semiconductor layer is formed, Alternatively, the oxide is oriented perpendicular to the upper surface of the semiconductor layer and has no grain boundary between adjacent crystal portions. It is preferable to use a nitride semiconductor film.

[0127] By using such materials for the semiconductor layer, fluctuations in electrical characteristics are suppressed, resulting in high reliability. This makes it possible to realize a low-power transistor.

[0128] Furthermore, the transistor having the above-described semiconductor layer can be used as a transistor due to its low off-state current. It is possible to retain the charge stored in the capacitor for a long period of time through such a transistor. By applying a transistor to each pixel, the gradation of the image displayed in each display area can be maintained while driving It is also possible to shut down the circuit. As a result, electronic devices with extremely low power consumption can be realized. It can be realized.

[0129] For stabilizing the characteristics of the transistor, it is preferable to provide an underlayer film. Inorganic films such as silicon oxide film, silicon nitride film, silicon oxynitride film, and silicon nitride oxide film The insulating film can be formed as a single layer or a laminated layer. CVD (Chemical Vapor Deposition) method (Plasma CVD method) , thermal CVD method, MOCVD (Metal Organic CVD) method, etc.), ALD ( Formed using Atomic Layer Deposition (ALD), coating, printing, etc. It should be noted that the undercoat film need not be provided if it is not necessary.

[0130] The FET 623 indicates one of the transistors formed in the driving circuit section 601. The drive circuit is made up of various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment, a driver integrated type in which a driving circuit is formed on a substrate is shown. However, this is not necessarily required, and the drive circuit can be formed externally rather than on the substrate. .

[0131] The pixel section 602 includes a switching FET 611, a current control FET 612 and its driver. The pixel is formed by a plurality of pixels including an anode 613 electrically connected to the drain. However, the present invention is not limited to this, and the pixel section may be a combination of three or more FETs and a capacitance element.

[0132] An insulator 614 is formed to cover the end of the anode 613. It can be formed by using a photosensitive acrylic resin film.

[0133] In order to improve the coverage of the EL layer and the like to be formed later, the insulating material 614 is For example, the material of the insulator 614 is When a positive photosensitive acrylic is used, the radius of curvature (0. It is preferable that the insulating material 614 has a curved surface with a thickness of 2 μm to 3 μm. Either a negative photosensitive resin or a positive photosensitive resin can be used.

[0134] An EL layer 616 and a cathode 617 are formed on the anode 613. It is desirable to use a material with a large work function for the anode 613. For example, ITO film, or silicon-containing indium tin oxide film, 2 to 20 wt% oxide Zinc-containing indium oxide film, titanium nitride film, chromium film, tungsten film, Zn film, Pt In addition to single layer films such as titanium nitride films, laminated films with aluminum as the main component, titanium nitride films, A three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and the like can be used. Furthermore, the multilayer structure provides low resistance as wiring and good ohmic contact. It can also function as an anode.

[0135] The EL layer 616 can be formed by a deposition method using a deposition mask, an inkjet method, or a spin coating method. The EL layer 616 is formed by various methods such as those described in the first and second embodiments. Other materials that make up the EL layer 616 include: It may be a low molecular weight compound or a high molecular weight compound (including an oligomer or dendrimer). .

[0136] Furthermore, the material used for the cathode 617 formed on the EL layer 616 is a material having a small work function. Materials with low resistance (Al, Mg, Li, Ca) or their alloys or compounds (MgAg, MgIn, It is preferable to use AlLi, etc. When light is transmitted through the cathode 617, a thin metal film and a transparent conductive film (I TO, indium oxide containing 2-20 wt% zinc oxide, indium tin containing silicon It is preferable to use a laminate of an oxide, zinc oxide (ZnO, etc.).

[0137] The anode 613, the EL layer 616, and the cathode 617 form a light-emitting device. The light-emitting device is the light-emitting device described in the first and second embodiments. The pixel portion is formed with a plurality of light-emitting devices. The device includes the light-emitting device described in the first and second embodiments and other components. The light emitting device may include both a light emitting device having a light emitting element and a light emitting device having a light emitting element.

[0138] Furthermore, the sealing substrate 604 is bonded to the element substrate 610 with a sealing material 605. A light-emitting device is placed in a space 607 surrounded by a sub-substrate 610, a sealing substrate 604, and a sealing material 605. The space 607 is filled with a filler material. In some cases, the gas is filled with an inert gas (nitrogen, argon, etc.), and in other cases, it is filled with a sealing material. By forming a recess in the sealing substrate and providing a desiccant there, deterioration due to the influence of moisture can be prevented. This is a preferable configuration because it can suppress the degradation.

[0139] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is desirable that these materials be as impermeable to moisture and oxygen as possible. Materials used for the sealing substrate 604 include glass substrates, quartz substrates, and FRP (Fiber Reinforced Plastics). reinforced plastics), PVF (polyvinyl fluoride), polyester A plastic substrate made of polyethylene or acrylic can be used.

[0140] Although not shown in Figure 2, a protective film may be provided on the cathode. The insulating film may be formed. In addition, a protective film may be formed to cover the exposed portion of the sealing material 605. The protective film may be formed on the surfaces and sides of the pair of substrates, the sealing layer, the insulating layer, It can be provided to cover the exposed side surfaces of the above.

[0141] The protective film can be made of a material that is difficult for impurities such as water to permeate. It is possible to effectively prevent impurities such as these from diffusing from the outside to the inside.

[0142] The materials that make up the protective film include oxides, nitrides, fluorides, sulfides, ternary compounds, and metals. Alternatively, polymers and the like can be used, for example, aluminum oxide, hafnium oxide, hafnium Lanthanum 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 Materials containing hafnium, aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, etc. Materials, nitrides containing titanium and aluminum, oxides containing titanium and aluminum , oxides containing aluminum and zinc, sulfides containing manganese and zinc, cerium and sulfides containing erbium and strontium, oxides containing erbium and aluminum, yttrium Materials containing oxides containing lithium and zirconium can be used.

[0143] The protective film can be formed using a film formation method that provides good step coverage. One such method is atomic layer deposition (ALD). The ALD method can be used to form protective materials. It is preferable to use it for films. By using the ALD method, it is possible to eliminate cracks, pinholes, etc. It is possible to form a protective film with reduced defects or with a uniform thickness. Damage to the processed member when forming the protective film can be reduced.

[0144] For example, by forming a protective film using the ALD method, it is possible to fabricate a surface with complex irregularities or a surface with a touch panel. A uniform protective film with few defects can be formed on the top, sides and back of the panel. .

[0145] As described above, the light-emitting devices described in the first and second embodiments were used to manufacture the A light emitting device having such a structure can be obtained.

[0146] The light emitting device of the present embodiment is the same as the light emitting device of the first and second embodiments. Since the semiconductor device is used, it is possible to obtain a light emitting device with excellent characteristics. The light emitting devices described in the first and second embodiments are light emitting devices with long lifetimes. Therefore, a light emitting device with good reliability can be obtained. 2. A light-emitting device using the light-emitting device described in 2. has good luminous efficiency, and therefore consumes little power. It may be an optical device.

[0147] In FIG. 3, a light-emitting device that emits white light is formed, and a colored layer (color filter) is provided. FIG. 3(A) shows an example of a full-color light-emitting device. an insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 1008, The first interlayer insulating film 1020, the second interlayer insulating film 1021, the peripheral portion 1042, and the pixel portion 1040 , a driving circuit unit 1041, anodes 1024W, 1024R, 1024G of the light-emitting device, 24B, a partition wall 1025, an EL layer 1028, a cathode 1029 of a light-emitting device, and a sealing substrate 103 1, sealing material 1032, etc. are shown.

[0148] In addition, in FIG. 3(A), the colored layers (red colored layer 1034R, green colored layer 1034G, blue The colored layer 1034B is provided on a transparent substrate 1033. A transparent substrate 1 on which a colored layer and a black matrix are provided may be further provided. The colored layer and the black matrix are aligned and fixed to the substrate 1001. The dust 1035 is covered with an overcoat layer 1036. The light-emitting layer is where light does not pass through the colored layers and goes out, and the light passes through the colored layers of each color and goes out. The light that does not pass through the colored layer is white, and the light that passes through the colored layer is red, green, or blue. This allows images to be expressed using four color pixels.

[0149] In FIG. 3(B), the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer An example in which a layer 1034B) is formed between the gate insulating film 1003 and the first interlayer insulating film 1020 As shown in the figure, the colored layer is provided between the substrate 1001 and the sealing substrate 1031. is also good.

[0150] In the light emitting device described above, light is taken in toward the substrate 1001 on which the FET is formed. The light emitting device has a bottom emission structure, but the light is taken in from the sealing substrate 1031 side. The light emitting device may have a top emission structure. A cross-sectional view of the light-emitting device is shown in FIG. 4. In this case, a substrate that does not transmit light is used as the substrate 1001. Until the connection electrode that connects the FET and the anode of the light-emitting device is fabricated, After that, a third interlayer insulating film 1037 is formed on the substrate 1031 in the same manner as in the case of the multi-emission light emitting device. The insulating film is formed to cover the electrode 1022. This insulating film may also serve as a planarizing layer. The interlayer insulating film 1037 may be formed using the same material as the second interlayer insulating film, or other known materials. It is possible.

[0151] The anodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are the anodes here. However, it may be formed as a cathode. In the case of an optical device, it is preferable that the anode is a reflective electrode. The EL layer 103 has the same structure as that described in the first and second embodiments, and In addition, the device structure is designed to produce white light emission.

[0152] In the top emission structure shown in Figure 4, the colored layers (red colored layer 1034R, green colored layer The sealing is performed by a sealing substrate 1031 provided with a blue color layer 1034G and a blue color layer 1034B. The sealing substrate 1031 has a black matrix disposed between the pixels. A coloring layer (red coloring layer 1034R, green coloring layer 1034G, The blue colored layer 1034B) and the black matrix are covered by the overcoat layer 1036. The sealing substrate 1031 may be covered. Note that a light-transmitting substrate is used. Although an example of full-color display using four colors, red, green, blue, and white, is shown here, there is no particular limitation. Alternatively, full color display may be performed using four colors of red, yellow, green, and blue, or three colors of red, green, and blue.

[0153] In a top-emission type light-emitting device, the microcavity structure can be suitably applied. The light-emitting device with a microcavity structure uses the anode as a reflective electrode and the cathode as a semi-transparent / semi-reflective electrode. At least one electrode is provided between the reflective electrode and the semi-transparent / semi-reflective electrode. It has an EL layer, and at least has a light-emitting layer that becomes a light-emitting region.

[0154] The reflectance of the reflective electrode for visible light is 40% to 100%, preferably 70% to 100%. %, and its resistivity is 1×10 -2 The film is assumed to be less than Ωcm. The semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%. , and its resistivity is 1×10 -2 It is assumed that the film has a resistance of Ωcm or less.

[0155] The light emitted from the light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transparent and semi-reflective electrode. The sound is reflected and resonates.

[0156] The light-emitting device is made by changing the thickness of the transparent conductive film, the composite material, the carrier transport material, etc. By doing so, the optical distance between the reflective electrode and the semi-transmissive / semi-reflective electrode can be changed. This strengthens the light of the resonating wavelength between the reflective electrode and the semi-transparent and semi-reflective electrode, and It can attenuate light of wavelengths that are not

[0157] The light reflected by the reflective electrode and returned (first reflected light) is semi-transmitted from the light emitting layer. The light that directly enters the semi-reflective electrode (first incident light) interferes greatly with the reflective electrode. The optical distance of the light-emitting layer is (2n-1)λ / 4 (where n is a natural number greater than or equal to 1, and λ is the amplified It is preferable to adjust the optical distance to a wavelength of the first light. By matching the phase of the reflected light with the phase of the first incident light, the light emitted from the light-emitting layer can be further amplified. do.

[0158] In the above configuration, even if the EL layer has a plurality of light-emitting layers, a single light-emitting For example, it may be combined with the above-mentioned tandem light-emitting device configuration. In addition, multiple EL layers are provided in one light-emitting device with a charge generating layer sandwiched between them, and each EL The layer may be configured to have one or more light-emitting layers.

[0159] The microcavity structure makes it possible to enhance the front-direction emission intensity of specific wavelengths. This allows for lower power consumption. In the case of a light-emitting device that displays images using a single pixel, the yellow light emission not only improves brightness, but also Since a microcavity structure tailored to the wavelength of each color can be applied, it is possible to achieve light-emitting devices with excellent characteristics. It can be placed.

[0160] The light emitting device of the present embodiment is the same as the light emitting device of the first and second embodiments. Since the semiconductor device is used, it is possible to obtain a light emitting device with excellent characteristics. The light emitting devices described in the first and second embodiments are light emitting devices with long lifetimes. Therefore, a light emitting device with good reliability can be obtained. 2. A light-emitting device using the light-emitting device described in 2. has good luminous efficiency, and therefore consumes little power. It may be an optical device.

[0161] Up to this point, we have explained about active matrix light emitting devices, but from now on we will be talking about passive light emitting devices. A passive matrix light-emitting device will be described. 5A is a perspective view showing the light emitting device, and FIG. 5B) is a cross-sectional view of FIG. 5A cut along XY. In FIG. 5, on a substrate 951, An EL layer 955 is provided between the electrode 952 and the electrode 956. The ends of the electrode 952 are It is covered with an insulating layer 953. A partition wall layer 954 is provided on the insulating layer 953. The sidewalls of the partition layer 954 become thicker between one sidewall and the other sidewall as they approach the substrate surface. That is, the cross section of the partition wall layer 954 in the short side direction has a slope such that the gap between the partition walls becomes narrower. The bottom side (the side that faces the same direction as the surface direction of the insulating layer 953 and is in contact with the insulating layer 953) ) is the upper side (the side that faces in the same direction as the surface direction of the insulating layer 953 and does not come into contact with the insulating layer 953). In this way, by providing the partition layer 954, it is possible to prevent the light emitting device from being damaged by static electricity or the like. In addition, the present invention can also be applied to passive matrix light emitting devices. The light emitting device according to the first embodiment and the second embodiment is used, and the light emitting device has high reliability. A light-emitting device with low power consumption can be obtained.

[0162] The light emitting device described above is composed of a large number of minute light emitting devices arranged in a matrix. Since it is possible to control each of these, it can be suitably used as a display device for displaying images. It is a light-emitting device.

[0163] This embodiment mode can be freely combined with other embodiment modes.

[0164] (Fourth embodiment) In this embodiment, the light-emitting device according to any one of the first and second embodiments is used as a lighting device. An example of using the lighting device as an illumination device will be described with reference to FIG. 6. FIG. 6(B) is a top view of the lighting device, and FIG. 6(A) is a bottom view of the lighting device. ) is a cross-sectional view taken along line ef in FIG. 6(B).

[0165] The lighting device of this embodiment has an anode 4 on a light-transmitting substrate 400 serving as a support. The anode 401 corresponds to the anode 101 in the second embodiment. When light is extracted from the anode 401 side, the anode 401 is formed from a light-transmitting material.

[0166] A pad 412 for supplying a voltage to the cathode 404 is formed on the substrate 400 .

[0167] An EL layer 403 is formed on the anode 401. The EL layer 403 is the same as that in the first embodiment and the second embodiment. The configuration of the EL layer 103 in the second embodiment, or the light-emitting units 511 and 512 and the charge generation This corresponds to a configuration in which the layer 513 is combined. For details of these configurations, refer to the relevant description. I want to be done that.

[0168] A cathode 404 is formed to cover the EL layer 403. The cathode 404 is the same as the cathode 1 in the second embodiment. When light is extracted from the anode 401 side, the cathode 404 is made of a material with high reflectivity. The cathode 404 is connected to a pad 412, and a voltage is applied to the cathode 404. can be.

[0169] As described above, the light-emitting device having the anode 401, the EL layer 403, and the cathode 404 is The lighting device shown in FIG. 1 has a high luminous efficiency. Therefore, the lighting device in this embodiment can be a lighting device with low power consumption.

[0170] The substrate 400 on which the light emitting device having the above structure is formed is sealed with a sealing substrate 407. The lighting device is completed by fixing and sealing using sealing materials 405 and 406. Either 405 or 406 may be used. In addition, the inner sealing material 406 (FIG. 6(B) ) (not shown) can also be mixed with a desiccant, which can absorb moisture. This leads to improved reliability.

[0171] In addition, a part of the pad 412 and the anode 401 is provided so as to extend outside the sealing materials 405 and 406. By doing so, it can be used as an external input terminal. An IC chip 420 or the like may be provided.

[0172] As described above, the lighting device according to the present embodiment uses the EL element according to the first and second embodiments. The light emitting device described above can be used to provide a light emitting device with good reliability. A light-emitting device with low power consumption can be provided.

[0173] (Embodiment 5) In this embodiment, the light emitting device according to the first and second embodiments is used as a part thereof. An example of an electronic device including the light-emitting device according to the first embodiment and the second embodiment will be described. The device has a long life and is a highly reliable light-emitting device. The electronic device described in the above item 1 can be an electronic device having a light emitting section with good reliability.

[0174] Examples of electronic devices to which the light-emitting device is applied include television sets (televisions, (also called television receivers), computer monitors, digital cameras, digital digital video cameras, digital photo frames, mobile phones (also known as mobile phones or mobile phone devices) (hereinafter referred to as "games"), portable game machines, personal digital assistants, sound reproduction devices, large game machines such as pachinko machines Specific examples of these electronic devices are listed below.

[0175] 7A shows an example of a television device. The television device includes a housing 710 A display unit 7103 is built into the housing 1. In this case, a stand 7105 is used to hold the housing The display unit 7103 can display images. The display portion 7103 is configured using the light-emitting device described in Embodiments 1 and 2. They are arranged in a matrix.

[0176] The television device can be operated using the operation switches on the housing 7101 or a separate remote control. This can be done by the remote control device 7110. This allows you to control the channel and volume, and the image displayed on the display unit 7103 In addition, the remote control operation device 7110 can be operated. A display portion 7107 for displaying information output from the

[0177] The television device is assumed to be equipped with a receiver, modem, etc. It can receive television broadcasts and can also communicate by wire or wireless via a modem. By connecting to a network, you can send and receive data in one direction (sender to receiver) or two directions (sender to receiver). It is also possible to communicate information between the recipient and the receiver, or between receivers themselves.

[0178] FIG. 7(B1) shows a computer, which includes a main body 7201, a housing 7202, a display portion 7203, and a keyboard. keyboard 7204, external connection port 7205, pointing device 7206, etc. The computer may be configured to use the light-emitting devices described in the first and second embodiments. The liquid crystal display panels are arranged in a matrix and used in the display portion 7203. The computer may be in the form shown in FIG. 7(B2). The keyboard 7204 and the pointing device 7206 are replaced by a second display unit 7207. The second display portion 7210 is a touch panel type. The input display on the display unit 7210 is operated with a finger or a special pen. The second display portion 7210 can be used not only for input display but also for other displays. The display unit 7203 may also be a touch panel. The two screens are connected by a hinge, which can damage the screen when storing or transporting it. This also prevents problems such as breakage.

[0179] FIG. 7C shows an example of a mobile terminal. The mobile phone is built in a housing 7401. In addition to the display unit 7402, operation buttons 7403, an external connection port 7404, a speaker 740 5, a microphone 7406, etc. The mobile phone is the same as that of the first embodiment and the second embodiment. A display portion 7402 in which the light-emitting devices according to embodiment 2 are arranged in a matrix is ​​provided. are.

[0180] The mobile terminal shown in FIG. 7C allows users to input information by touching the display portion 7402 with a finger or the like. In this case, it is possible to make a call or create an email. Operations such as turning on / off the camera can be performed by touching the display portion 7402 with a finger or the like.

[0181] The screen of the display unit 7402 has three main modes. The first is a display mode that mainly displays images. The first mode is a display mode, and the second mode is an input mode that mainly inputs information such as characters. This is a display + input mode that combines two modes: display mode and input mode.

[0182] For example, when making a call or creating an email, the display unit 7402 is used to input characters. This is the main character input mode, and you can input characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402. I wish.

[0183] In addition, the mobile terminal may include a sensor for detecting tilt, such as a gyro or acceleration sensor. By providing a device, the orientation of the mobile terminal (portrait or landscape) can be determined and the screen display of the display portion 7402 can be displayed. The display can be switched automatically.

[0184] The screen mode can be switched by touching the display portion 7402 or by operating the housing 7401. This is done by operating the button 7403. Also, depending on the type of image displayed on the display unit 7402, For example, if the image signal to be displayed on the display unit is a video signal, If it is data, the display mode is switched to, and if it is text data, the input mode is switched to.

[0185] In the input mode, the optical sensor of the display unit 7402 detects a signal and displays it. If there is no input by touch operation on the part 7402 for a certain period of time, the screen mode is changed to the input mode. Alternatively, the display mode may be switched from the normal mode to the display mode.

[0186] The display portion 7402 can also function as an image sensor. By touching the device with your palm or fingers and capturing an image of your palm print or fingerprint, you can authenticate your identity. In addition, a backlight that emits near-infrared light to the display unit or a sensing light that emits near-infrared light By using a source, it is also possible to image finger veins, palm veins, etc.

[0187] Note that the structure described in this embodiment mode may be obtained by appropriately combining the structures described in any of Embodiment Modes 1 to 4. They can be used in combination.

[0188] As described above, the light emitting device according to the first and second embodiments can be applied to the light emitting apparatus. The range of applications is extremely wide, and this light-emitting device can be applied to electronic devices in a wide range of fields. By using the light emitting devices described in the first and second embodiments, reliability is improved. You can get high quality electronic equipment.

[0189] FIG. 8(A) is a schematic diagram showing an example of a cleaning robot.

[0190] The cleaning robot 5100 has a display 5101 on the top surface and multiple The camera 5102, the brush 5103, and the operation button 5104 are also shown. However, the underside of the cleaning robot 5100 is provided with tires, a suction port, etc. The robot 5100 also has an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezo sensor, It is equipped with various sensors such as a sensor, a light sensor, and a gyro sensor. 100 is equipped with wireless communication means.

[0191] The cleaning robot 5100 moves by itself, detects the dust 5120, and sucks it out from the suction port on the bottom. It can suck up dirt.

[0192] In addition, the cleaning robot 5100 analyzes the image captured by the camera 5102 and detects the wall, furniture, or It can detect obstacles such as steps. Image analysis can also detect obstacles such as wiring. If an object that may get tangled in the brush 5103 is detected, the rotation of the brush 5103 can be stopped. can.

[0193] The display 5101 can display the remaining battery level and the amount of dust sucked. The route traveled by the cleaning robot 5100 can be displayed on the display 5101. In addition, the display 5101 is a touch panel, and the operation button 5104 is It may be provided in the ray 5101.

[0194] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. The images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the Cleaning Robot 5100 can check the status of the room even when he is away from home. In addition, the display on the display 5101 can be displayed on a mobile electronic device such as a smartphone. You can also check it at 5140.

[0195] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0196] The robot 2100 shown in FIG. 8(B) includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, upper camera 2103, speaker 2104, display 2105, It is equipped with an internal camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0197] The microphone 2102 has a function of detecting the user's voice and environmental sounds. The speaker 2104 has a function of emitting sound. The device 2102 and the speaker 2104 can be used to communicate with the user. It is possible.

[0198] The display 2105 has the function of displaying various information. Any information desired by the user can be displayed on the display 2105. The display 2105 may be equipped with a touch panel. It may be an information terminal that can be charged by placing it in a fixed position on the robot 2100. and enables data transfer.

[0199] The upper camera 2103 and the lower camera 2106 are used to capture images of the surroundings of the robot 2100. The obstacle sensor 2107 detects the obstacles in the robot 210 by using the moving mechanism 2108. When moving forward, the robot can sense whether there are any obstacles in its path. 00 uses an upper camera 2103, a lower camera 2106, and an obstacle sensor 2107. The light-emitting device according to one embodiment of the present invention can recognize the surrounding environment and move safely. It can be used for the display 2105.

[0200] FIG. 8(C) is a diagram showing an example of a goggle-type display. For example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, Connection terminal 5006, sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation (including those that measure radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), The device includes a microphone 5008, a second display unit 5002, a support unit 5012, an earphone 5013, etc. do.

[0201] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002. can.

[0202] FIG. 9 shows a configuration of the light-emitting device according to the first and second embodiments in an electric lighting device. This is an example of a desk lamp. The desk lamp shown in FIG. 9 is made up of a housing 2001 and a light source 2002. The lighting device described in Embodiment 3 may be used as the light source 2002.

[0203] FIG. 10 shows the light-emitting device according to the first and second embodiments installed in an indoor lighting device 3. 001. The light-emitting devices described in the first and second embodiments are Since the light emitting device is highly reliable, it can be used as a highly reliable lighting device. Since the light-emitting devices described in the first and second embodiments can be made larger in area, It can be used as a large-area lighting device. The light-emitting device described is thin and can be used as a thin lighting device. become.

[0204] The light emitting devices according to the first and second embodiments can be used for automobile windshields and windows. The present invention can also be implemented on a flash board. The light emitting device is used in an automobile windshield or dashboard. The display areas 5200 to 5203 are the light-emitting devices described in Embodiments 1 and 2. This is a display area provided using a device.

[0205] In this embodiment, the display area 5200 and the display area 5201 are provided on the windshield of a car. 1 and 2. In the light-emitting device described in the second embodiment, the anode and the cathode are made of light-transmitting electrodes. This allows the display device to be in a see-through state, where the other side can be seen through. Yes, if the display is see-through, it can be installed on the windshield of a car. It can be installed without obstructing the view. When a transistor is provided, an organic transistor made of an organic semiconductor material or a transistor made of an oxide semiconductor may be used. A light-transmitting transistor such as a transistor is preferably used.

[0206] The display area 5202 is the display device described in Embodiments 1 and 2 provided in the pillar portion. The display device is equipped with an optical device. The display area 5202 is equipped with an imaging device mounted on the vehicle body. By projecting images from the steps, it is possible to compensate for the view obstructed by the pillars. Similarly, the display area 5203 provided on the dashboard is not blocked by the vehicle body. By projecting images from an imaging device installed outside the vehicle, the driver can see the blind spots. By projecting images to complement the invisible parts, safety can be improved. This allows the driver to check for safety more naturally and without any discomfort.

[0207] The display area 5203 also displays navigation information, speedometer, tachometer, odometer, fuel gauge, gear It can provide various information by displaying the status, air conditioner settings, etc. The display items and layout can be changed as needed to suit the user's preferences. This information can also be provided in the display areas 5200 to 5203. The display areas 5200 to 5203 can also be used as lighting devices.

[0208] 12(A) and (B) show a foldable mobile information terminal 5150. The foldable mobile information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 515 12(A) shows the mobile information terminal 5150 in an unfolded state. Fig. 5B) shows the portable information terminal 5150 in a folded state. Although it has a large display area 5152, it is compact and highly portable when folded.

[0209] The display area 5152 can be folded in half by the bend 5153. 3 is composed of an expandable member and multiple support members, and when folding, The member is elongated, and the bent portion 5153 has a curvature radius of 2 mm or more, preferably 3 mm or more. It can be folded.

[0210] The display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). The light-emitting device of one embodiment of the present invention can be used in the display region 5152. Cut.

[0211] 13(A) to 13(C) show a foldable mobile information terminal 9310. 13(A) shows the mobile information terminal 9310 in an unfolded state. The mobile information terminal 9310 is shown in a state in which it is changing from one folded state to the other. FIG. 13C shows the portable information terminal 9310 in a folded state. The foldable design offers excellent portability and a seamless, large viewing area when unfolded. This provides excellent visibility of the display.

[0212] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. The display panel 9311 is a touch panel equipped with a touch sensor (input device). The display panel 9311 may be a display panel (input / output device). The two housings 9315 are bent to open the mobile information terminal 9310. The light-emitting device of one embodiment of the present invention can be reversibly transformed from a folded state to a folded state. It can be used for the display panel 9311. [Example]

[0213] In this example, light-emitting devices 1 to 3 of one embodiment of the present invention and a light-emitting device of a comparative example The comparative light-emitting devices 1 and 2 will be described. The organic light-emitting devices used in the light-emitting devices 1 to 3, the comparative light-emitting device 1, and the comparative light-emitting device 2 The structural formula of the compound is shown below.

[0214] [ka]

[0215] (Method for fabricating light-emitting device 1) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0216] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0217] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0218] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N-(1,1'-biphenyl-4-yl)-9, 9-Dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] -9H-fluorene-2-amine (abbreviation: PCBBiF) and ALD-MP001Q ( (Material serial number: 1S20170124) in a weight ratio of 1:0.1 (=PCBBiF:ALD-MP001Q) and hole injection were performed by co-evaporating 10 nm A layer 111 was formed.

[0219] Next, PCBBiF was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino- p-Terphenyl (abbreviation: DBfBB1TP) was evaporated to a thickness of 10 nm to form a hole transport layer. The second hole transport layer 112-2 also functions as an electron blocking layer. do.

[0220] Next, 7-[4-(10-phenyl-9-anthryl)-2-(2-methyl-2-phenyl)-1,3-dimethyl-2,4-dimethyl-2,5-dimethyl-2,6 ... )phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), N,N'-(pyrene-1,6-diyl)bis[(6,N- Diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6B nfAPrn-03) in a weight ratio of 1:0.03 (=cgDBCzPA:1,6BnfA The light-emitting layer 113 was formed to a thickness of 25 nm by co-evaporation so that the film was Prn-03).

[0221] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0222] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm. The electron injection layer 115 is formed by depositing aluminum to a thickness of 200 nm. The cathode 102 was formed by vapor deposition, and the light-emitting device 1 of this example was fabricated.

[0223] (Method for fabricating light-emitting device 2) The light-emitting device 2 is a light-emitting device 1 in which PCBBiF is replaced with PCBBiF represented by the above structural formula (vii). N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d] The device was fabricated in the same manner as light-emitting device 1, except that furan-8-amine (BBABnf) was used instead. Ta.

[0224] (Method for fabricating light-emitting device 3) The light-emitting device 3 is a light-emitting device 2 in which DBfBB1TP is replaced by the compound represented by the above structural formula (viii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carba The light-emitting device was fabricated in the same manner as in device 2, except that the ZnO was replaced with PCzN2.

[0225] (Method for producing comparative light-emitting device 1) Comparative light-emitting device 1 is 2mDBTBPDBq-II of light-emitting device 1 and cgDBCzPA The light-emitting device was fabricated in the same manner as in device 1, except that the

[0226] (Method for producing comparative light-emitting device 2) Comparative light-emitting device 2 is the same as comparative light-emitting device 1, except that DBfBB1TP is replaced with PCzN2. Other than that, the comparative light-emitting device was fabricated in the same manner as the comparative light-emitting device 1.

[0227] Light-emitting devices 1 to 3, comparative light-emitting device 1, and comparative light-emitting device 2 The child structure is summarized in the table below.

[0228] [Table 1]

[0229] In addition, the HOMO level, LUMO level, and electric field strength [V The table below summarizes the electron mobility when the square root of [μm / cm] is 600.

[0230] [Table 2]

[0231] These light-emitting devices were placed in a nitrogen atmosphere glove box, and the light-emitting devices were placed in a nitrogen atmosphere glove box. The process of sealing with a glass substrate to prevent exposure to heat (sealing material is applied around the element and sealed) After UV treatment at the time of shutdown and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices were The reliability and reliability were measured at room temperature.

[0232] The brightness of the light-emitting devices 1 to 3, the comparative light-emitting device 1, and the comparative light-emitting device 2 The current efficiency-current density characteristics are shown in Fig. 14, the current efficiency-luminance characteristics are shown in Fig. 15, and the luminance-voltage characteristics are shown in Fig. 16. The current-voltage characteristics are shown in Fig. 17, the external quantum efficiency-luminance characteristics are shown in Fig. 18, and the emission spectrum is shown in Fig. 19. The figure shows the luminance of each light-emitting device at 1000 cd / m 2 Shows the main characteristics of the area Shown in 3.

[0233] [Table 3]

[0234] 14 to 19 and Table 3, light-emitting devices 1 to 17 according to one embodiment of the present invention are shown. All of the devices 3 were found to be blue-emitting devices with good characteristics.

[0235] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 20. As shown in FIG. 20, light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, The luminance after 300 hours was 86% or more of the initial luminance, and the luminance of light-emitting element 2 and light-emitting element 3 The brightness remains at 90% or more, and the decrease in brightness due to the accumulation of operating time is small, resulting in a long-lasting light emission. It turned out to be a device.

[0236] On the other hand, when the square root of the electric field strength [V / cm] is 600, the electron mobility is 7.7 × 10 - 5 cm 2 The comparative light-emitting device using cgDBCzPA, a material with high / Vs, as the electron transport layer is After 300 hours, the brightness of comparative light-emitting element 1 was 84% ​​or less of the initial brightness, and that of comparative light-emitting element 2 These comparative light-emitting devices have hole injection and transport layers. The electron mobility of the electron transport layer is too high compared to the capacity, resulting in a narrow light-emitting region in the light-emitting layer. It is thought that deterioration is accelerated because the gap becomes narrower.

[0237] In addition, the comparative light-emitting element corresponds to the sixth organic compound and the seventh organic compound, cgDBCzPA. Therefore, there is no difference in the LUMO levels of the sixth organic compound and the seventh organic compound. Therefore, the structure is such that electrons are more easily injected into the light-emitting layer 113, and the electron excess This configuration makes it easy for a state to form.

[0238] Furthermore, in the comparative light-emitting element 2, the electron transport layer has a high transport property, and the first hole transport layer has a high The HOMO level of the organic compound PCBBiF used and the SiO2 used for the second hole transport layer The difference between the HOMO level of PCzN2 and that of PCzN2 is 0.36 eV, which is larger than 0.2 eV. Therefore, in the comparative light-emitting element 2, holes are transported from the first hole transport layer to the second hole transport layer. This suppresses the injection of electrons and makes it difficult to balance holes and electrons, resulting in the deterioration of the performance of these devices. It is the light-emitting element that has the greatest degradation among the other light-emitting elements. The current efficiency and external quantum efficiency of Device 2 are also low, indicating that electrons recombine due to an excess of electrons. It is thought that the number of electrons that escape from the light-emitting layer without being absorbed is also increasing. [Example]

[0239] In this example, light-emitting devices 4 to 6 according to one embodiment of the present invention and a light-emitting device of a comparative example were used. The comparative light-emitting device 3 will be described. The structural formula of the organic compound used in Comparative Light-Emitting Device 3 is shown below.

[0240] [ka]

[0241] (Method for fabricating light-emitting device 4) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0242] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0243] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0244] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N-(1,1'-biphenyl-4-yl)-9, 9-Dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] -9H-fluorene-2-amine (abbreviation: PCBBiF) and ALD-MP001Q ( (Material serial number: 1S20170124) in a weight ratio of 1:0.1 (=PCBBiF:ALD-MP001Q) and hole injection were performed by co-evaporating 10 nm A layer 111 was formed.

[0245] Next, PCBBiF was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino- p-Terphenyl (abbreviation: DBfBB1TP) was evaporated to a thickness of 10 nm to form a hole transport layer. The second hole transport layer 112-2 also functions as an electron blocking layer. do.

[0246] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-(2-naphthyl)-1 ...1-(2-naphthyl) αN-βNPAnth) and the above structural formula (iv) N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[ b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03 ) in a weight ratio of 1:0.03 (=αN-βNPAnth:1,6BnfAPrn-03) The light-emitting layer 113 was formed to a thickness of 25 nm by co-evaporation.

[0247] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0248] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm. The electron injection layer 115 is formed by depositing aluminum to a thickness of 200 nm. The cathode 102 was formed by vapor deposition, and the light-emitting device 4 of this example was fabricated.

[0249] (Method for fabricating light-emitting device 5) The light-emitting device 5 is a light-emitting device 4 in which PCBBiF is replaced with PCBBiF represented by the above structural formula (vii). N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d] The device was fabricated in the same manner as light-emitting device 4, except that furan-8-amine (BBABnf) was used instead. Ta.

[0250] (Method for fabricating light-emitting device 6) The light-emitting device 6 is a light-emitting device in which DBfBB1TP in the light-emitting device 5 is replaced with DBfBB1TP represented by the above structural formula (viii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carba The light-emitting device was fabricated in the same manner as in device 5, except that the organic EL element was replaced with PCzN2.

[0251] (Method for producing comparative light-emitting device 3) Comparative light-emitting device 3 is a light-emitting device 4 with 2mDBTBPDBq-II replaced with αN-βNPAn The light-emitting device was fabricated in the same manner as in device 4, except that th was used.

[0252] The device structures of light-emitting devices 4 to 6 and comparative light-emitting device 3 are summarized in the table below. do.

[0253] [Table 4]

[0254] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0255] [Table 5]

[0256] These light-emitting devices were placed in a nitrogen atmosphere glove box, and the light-emitting devices were placed in a nitrogen atmosphere glove box. The process of sealing with a glass substrate to prevent exposure to heat (sealing material is applied around the element and sealed) After UV treatment at the time of shutdown and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices were The reliability and reliability were measured at room temperature.

[0257] The luminance-current density characteristics of the light-emitting devices 4 to 6 and the comparative light-emitting device 3 are shown in FIG. The current efficiency-luminance characteristics are shown in Figure 22, the luminance-voltage characteristics in Figure 23, and the current-voltage characteristics in Figure 24. 4, the external quantum efficiency-luminance characteristics are shown in Fig. 25, and the emission spectra are shown in Fig. 26. 1000cd / m of optical device 2 The main characteristics of the area are shown in Table 6.

[0258] [Table 6]

[0259] 21 to 26 and Table 6, light-emitting devices 4 to 6 according to one embodiment of the present invention are shown. All of the compounds 6 were found to be blue-emitting devices with good characteristics.

[0260] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 27. As shown in FIG. 27, light-emitting device 4, which is a light-emitting device according to one embodiment of the present invention, The light-emitting device 6 maintained about 94% of its initial brightness even after 300 hours of driving. It was found that the decrease in brightness due to the accumulation of operating time was small, making it a light-emitting device with a long lifespan. .

[0261] Comparative light-emitting element 3 has αN-βNPAnth in both the sixth and seventh organic compounds. Therefore, there is no difference in the LUMO levels of the sixth organic compound and the seventh organic compound. Therefore, the structure is such that electrons are more easily injected into the light-emitting layer 113, and the electrons It is thought that an excessive state is easily formed, accelerating deterioration. [Example]

[0262] In this example, a light-emitting device 7 and a light-emitting device 8 according to one embodiment of the present invention will be described. The structural formulae of the organic compounds used in light-emitting device 7 and light-emitting device 8 are shown below.

[0263] [ka]

[0264] (Method for fabricating light-emitting device 7) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0265] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0266] Then, 10-4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0267] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (vii) was obtained. Nylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and ALD-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) and ALD-MP001Q in a weight ratio of 1:0.1 (=BBABnf:ALD-MP001Q). A hole injection layer 111 was formed to a thickness of 0 nm by co-evaporation.

[0268] Next, BBABnf was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino- p-Terphenyl (abbreviation: DBfBB1TP) was evaporated to a thickness of 10 nm to form a hole transport layer. The second hole transport layer 112-2 also functions as an electron blocking layer. do.

[0269] Next, 7-[4-(10-phenyl-9-anthryl)-2-(2-methyl-2-phenyl)-1,3-dimethyl-2,4-dimethyl-2,5-dimethyl-2,6 ... )phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 3,10-bis[N-(9-phenyl-9H-carbazole) represented by the above structural formula (x)] -2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzof Ran (abbreviation: 3,10PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (= 25nm co-evaporation to give cgDBCzPA:3,10PCA2Nbf(IV)-02 The light-emitting layer 113 was formed by deposition.

[0270] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0271] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm. The electron injection layer 115 is formed by depositing aluminum to a thickness of 200 nm. The cathode 102 was formed by vapor deposition, and the light-emitting device 7 of this example was fabricated.

[0272] (Method for fabricating light-emitting device 8) The light-emitting device 8 is the same as the light-emitting device 7 except that the cgDBCzPA is represented by the above structural formula (ix). 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene ( The device was fabricated in the same manner as light-emitting device 7, except that the αN-βNPAnth was used.

[0273] The device structures of light-emitting device 7 and light-emitting device 8 are summarized in the table below.

[0274] [Table 7]

[0275] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0276] [Table 8]

[0277] These light-emitting devices were placed in a nitrogen atmosphere glove box, and the light-emitting devices were placed in a nitrogen atmosphere glove box. The process of sealing with a glass substrate to prevent exposure to heat (sealing material is applied around the element and sealed) After UV treatment at the time of shutdown and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices were The reliability and reliability were measured at room temperature.

[0278] The luminance vs. current density characteristics of light-emitting device 7 and light-emitting device 8 are shown in Figure 28, and the current efficiency vs. luminance The characteristics are shown in Figure 29, the brightness-voltage characteristics are shown in Figure 30, the current-voltage characteristics are shown in Figure 31, and the external quantum efficiency The luminance characteristics are shown in Figure 32 and the emission spectrum in Figure 33. 0 cd / m 2 The main characteristics of the area are shown in Table 9.

[0279] [Table 9]

[0280] 28 to 33 and Table 9, the light-emitting device 7 and the light-emitting device 8 according to one embodiment of the present invention are All of the devices were found to be blue-emitting devices with good characteristics.

[0281] In addition, the current density is 50mA / cm2 Figure 1 shows a graph showing the change in brightness over time. 34. As shown in FIG. 34, light-emitting device 7, which is a light-emitting device according to one embodiment of the present invention, and Light-emitting Device 8, both of which showed 90% or more of their initial luminance even after 300 hours. The device maintains its brightness and exhibits little decrease in brightness with increasing driving time, making it a light-emitting device with a long lifespan. It was found that... [Example]

[0282] In this example, a light-emitting device 9 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0283] [ka]

[0284] (Method for fabricating light-emitting device 9) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0285] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0286] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0287] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (vii) was obtained. Nylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and ALD-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) and ALD-MP001Q in a weight ratio of 1:0.1 (=BBABnf:ALD-MP001Q). A hole injection layer 111 was formed to a thickness of 0 nm by co-evaporation.

[0288] Next, BBABnf was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (vii i) represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H- Carbazole (abbreviation: PCzN2) was evaporated to a thickness of 10 nm to form a hole transport layer 112 The second hole transport layer 112-2 also functions as an electron blocking layer.

[0289] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-(2-naphthyl)-1 ...1-(2-naphthyl) αN-βNPAnth) and the above structural formula (x) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenyl] phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10 PCA2Nbf(IV)-02) and a weight ratio of 1:0.015 (=αN-βNPAnth :3,10PCA2Nbf(IV)-O2) to form a 25 nm light-emitting layer 11 3 was formed.

[0290] Then, on the light-emitting layer 113, 2-{4-[9,10-di( Naphthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoyl Midazole (abbreviation: ZADN) and 8-hydroxyquinolinol represented by the above structural formula (xx) Tritium (abbreviation: Liq) was added in a weight ratio of 1:0.9 (= ZADN: Liq). The electron transport layer 114 was formed by co-evaporation to a thickness of 25 nm.

[0291] After forming the electron transport layer 114, Liq was evaporated to a thickness of 1 nm to form the electron injection layer 1 15, and then aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light-emitting device 9 of this example.

[0292] The element structure of the light-emitting device 9 is summarized in the table below.

[0293] [Table 10]

[0294] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0295] [Table 11]

[0296] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element and sealed) After the test, the initial characteristics and signal strength of the light-emitting device 9 were measured. The reliability of the sample was measured at room temperature.

[0297] The luminance vs. current density characteristics of the light-emitting device 9 are shown in FIG. 35, the current efficiency vs. luminance characteristics in FIG. 36, and the luminance The -voltage characteristics are shown in Figure 37, the current-voltage characteristics in Figure 38, and the external quantum efficiency-luminance characteristics in Figure 39. The emission spectrum is shown in Figure 40. The emission spectrum of the light-emitting device is 1000 cd / m 2 Nearby The main properties are shown in Table 12.

[0298] [Table 12]

[0299] 35 to 40 and Table 12, it can be seen that the light-emitting device 9 according to one embodiment of the present invention has excellent characteristics. It was found to be a blue light-emitting device.

[0300] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 41. As shown in FIG. 41, light-emitting device 9, which is a light-emitting device according to one embodiment of the present invention, Even after 600 hours, the brightness remained at around 90% of the initial brightness, It was found that the decrease in luminance due to heating was particularly small, and that the light-emitting device had an extremely long life.

[0301] The deterioration curve of the light-emitting element 9 shows that the luminance first decreases and then increases. Due to this deterioration behavior, the light-emitting element 9 has a very short life. It is a long light emitting element. [Example]

[0302] In this example, a light-emitting device 10 according to one embodiment of the present invention will be described. The structural formulas of the organic compounds used are shown below.

[0303] [ka]

[0304] (Method of Making Light-Emitting Device 10) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0305] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0306] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0307] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N-(1,1'-biphenyl-4-yl)-9, 9-Dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] -9H-fluorene-2-amine (abbreviation: PCBBiF) and ALD-MP001Q ( (Material serial number: 1S20170124) in a weight ratio of 1:0.1 (=PCBBiF:ALD-MP001Q) and hole injection were performed by co-evaporating 10 nm A layer 111 was formed.

[0308] Next, PCBBiF was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino- p-Terphenyl (abbreviation: DBfBB1TP) was evaporated to a thickness of 10 nm to form a hole transport layer. The second hole transport layer 112-2 also functions as an electron blocking layer. do.

[0309] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-(2-naphthyl)-1 ...1-(2-naphthyl) αN-βNPAnth) and the above structural formula (x) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N- phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,1 PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (=αN-βNPAnt h:3,10PCA2Nbf(IV)-O2) to form a 25 nm thick light-emitting layer 1 Formed 13.

[0310] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0311] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm. The electron injection layer 115 is formed by depositing aluminum to a thickness of 200 nm. The cathode 102 was formed by vapor deposition, and the light-emitting device 10 of this example was fabricated.

[0312] The device structure of light-emitting device 10 is summarized in the table below.

[0313] [Table 13]

[0314] In addition, the HOMO level, LUMO level, and electric field strength [V The table below summarizes the electron mobility when the square root of [μm / cm] is 600.

[0315] [Table 14]

[0316] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element and sealed) After the light-emitting device 10 was subjected to UV treatment and heat treatment at 80° C. for 1 hour, the initial characteristics and Reliability was measured at room temperature.

[0317] The luminance vs. current density characteristics of the light-emitting device 10 are shown in FIG. 47, the current efficiency vs. luminance characteristics in FIG. 48, and the luminance vs. The intensity-voltage characteristics are shown in Figure 49, the current-voltage characteristics are shown in Figure 50, and the external quantum efficiency-luminance characteristics are shown in Figure 51. The emission spectrum of the light-emitting device is shown in Figure 52. 2 Nearby The main characteristics of the

[0318] [Table 15]

[0319] 47 to 52 and Table 15, the light-emitting device 10 according to one embodiment of the present invention has good characteristics. It was found to be a blue light-emitting device.

[0320] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 53. As shown in FIG. 53, light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, 0 means that the brightness after 600 hours is maintained at about 90% of the initial brightness, and the accumulated operating time It was found that the decrease in luminance due to the increase was small, and the light-emitting device had a long life. [Example]

[0321] In this example, a light-emitting device 11 according to one embodiment of the present invention will be described. The structural formulas of the organic compounds used are shown below.

[0322] [ka]

[0323] (Method for fabricating light-emitting device 11) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0324] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0325] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0326] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N-(1,1'-biphenyl-4-yl)-9, 9-Dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] -9H-fluorene-2-amine (abbreviation: PCBBiF) and ALD-MP001Q ( (Material serial number: 1S20170124) in a weight ratio of 1:0.1 (=PCBBiF:ALD-MP001Q) and hole injection were performed by co-evaporating 10 nm A layer 111 was formed.

[0327] Next, PCBBiF was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (ii). N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino- p-Terphenyl (abbreviation: DBfBB1TP) was evaporated to a thickness of 10 nm to form a hole transport layer. The second hole transport layer 112-2 also functions as an electron blocking layer. do.

[0328] Next, 7-[4-(10-phenyl-9-anthryl)-2-(2-methyl-2-phenyl)-1,3-dimethyl-2,4-dimethyl-2,5-dimethyl-2,6 ... )phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 3,10-bis[N-(9-phenyl-9H-carbazole) represented by the above structural formula (x)] -2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzof Ran (abbreviation: 3,10PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (= 25nm co-evaporation to give cgDBCzPA:3,10PCA2Nbf(IV)-02 The light-emitting layer 113 was formed by deposition.

[0329] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0330] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm. The electron injection layer 115 is formed by depositing aluminum to a thickness of 200 nm. The cathode 102 was formed by vapor deposition, and the light-emitting device 11 of this example was fabricated.

[0331] The device structure of the light-emitting device 11 is summarized in the table below.

[0332] [Table 16]

[0333] In addition, the HOMO level, LUMO level, and electric field strength [V The table below summarizes the electron mobility when the square root of [μm / cm] is 600.

[0334] [Table 17]

[0335] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element and sealed) After the light-emitting device 11 was subjected to UV treatment and heat treatment at 80° C. for 1 hour, the initial characteristics and Reliability was measured at room temperature.

[0336] The luminance vs. current density characteristics of the light-emitting device 11 are shown in FIG. 54, the current efficiency vs. luminance characteristics in FIG. 55, and the luminance vs. The luminance-voltage characteristics are shown in Figure 56, the current-voltage characteristics in Figure 57, and the external quantum efficiency-luminance characteristics in Figure 58. The emission spectrum of the light-emitting device is shown in Figure 59. 2 Nearby The main properties of the

[0337] [Table 18]

[0338] 54 to 59 and Table 18, the light-emitting device 11 according to one embodiment of the present invention has good characteristics. It was found to be a blue light-emitting device.

[0339] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 60. As shown in FIG. 60, light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, 1 maintains 80% or more of the initial brightness after 600 hours, and It was found that the decrease in luminance due to the increase was small, and the light-emitting device had a long life. [Example]

[0340] In this example, a light-emitting device 12 according to one embodiment of the present invention will be described. The structural formulas of the organic compounds used are shown below.

[0341] [ka]

[0342] (Method of Making Light-Emitting Device 12) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0343] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0344] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0345] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (vii) was obtained. Nylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and ALD-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) and ALD-MP001Q in a weight ratio of 1:0.1 (=BBABnf:ALD-MP001Q). A hole injection layer 111 was formed to a thickness of 0 nm by co-evaporation.

[0346] Next, BBABnf was deposited on the hole injection layer 111 to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 was formed by vapor deposition of a compound represented by the above structural formula (vii i) represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H- Carbazole (abbreviation: PCzN2) was evaporated to a thickness of 10 nm to form a hole transport layer 112 The second hole transport layer 112-2 also functions as an electron blocking layer.

[0347] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-(2-naphthyl)-1 ...1-(2-naphthyl) αN-βNPAnth) and the above structural formula (x) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenyl] phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10 PCA2Nbf(IV)-02) and a weight ratio of 1:0.015 (=αN-βNPAnth :3,10PCA2Nbf(IV)-O2) to form a 25 nm light-emitting layer 11 3 was formed.

[0348] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0349] After forming the electron transport layer 114, LiF was evaporated to a thickness of 1 nm to form the electron injection layer 1 15, and then aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light-emitting device 12 of this example.

[0350] The device structure of the light emitting device 12 is summarized in the table below.

[0351] [Table 19]

[0352] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0353] [Table 20]

[0354] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element and sealed) After the test, the initial characteristics and Reliability was measured at room temperature.

[0355] The luminance vs. current density characteristics of the light-emitting device 12 are shown in FIG. 61, the current efficiency vs. luminance characteristics in FIG. 62, and the luminance vs. The luminance-voltage characteristics are shown in Figure 63, the current-voltage characteristics in Figure 64, and the external quantum efficiency-luminance characteristics in Figure 65. The emission spectrum of the light-emitting device is shown in Figure 66. 2 Nearby The main properties of the

[0356] [Table 21]

[0357] 61 to 66 and Table 21, it can be seen that the light-emitting device 12 according to one embodiment of the present invention has good characteristics. It was found to be a good blue light-emitting device.

[0358] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. 67. As shown in FIG. 67, light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, 2 maintains 90% or more of its initial brightness even after 600 hours of operation. The decrease in brightness due to the increase in the temperature was particularly small, and it was found that this light-emitting device has an extremely long lifespan. . [Example]

[0359] In this example, light-emitting devices 13 to 20 of one embodiment of the present invention will be described. The structural formulas of the organic compounds used in the light-emitting devices 13 to 20 are shown below.

[0360] [ka]

[0361] [ka]

[0362] (Method for fabricating light-emitting device 13) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 2 mm x 2 mm.

[0363] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water. After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0364] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside pressure has been reduced to about 100 Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0365] Next, the substrate on which the anode 101 is formed is placed in a vacuum chamber so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation device, and evaporation was performed on the anode 101 using resistance heating. By this method, 4-(6;2'-binaphthyl-2-yl)- 4',4''-diphenyltriphenylamine (abbreviation: BBA(βN2)B) and ALD -MP001Q (Breakdown Workshop Co., Ltd., Material serial number: 1S20170124) and The weight ratio was 1:0.1 (=BBA(βN2)B:ALD-MP001Q). A hole injection layer 111 was formed to a thickness of 0 nm by co-evaporation.

[0366] Next, on the hole injection layer 111, a layer of BBA(βN2)B was formed as a first hole transport layer 112-1. After that, a compound having the above structural formula ( viii) 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl- 9H-carbazole (abbreviation: PCzN2) was evaporated to a thickness of 10 nm to form a hole transport layer The second hole transport layer 112-2 also functions as an electron blocking layer. do.

[0367] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-2-(2-naphthyl)-1 ...1-(2-naphthyl) αN-βNPAnth) and the above structural formula (x) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N- phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,1 PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (=αN-βNPAnt h:3,10PCA2Nbf(IV)-O2) to form a 25 nm thick light-emitting layer 1 Formed 13.

[0368] Then, on the light-emitting layer 113, 2-[3'-(dibenzothiophene)-2-(3-methyl-2-benzophenone]-1-yl]-2-(3-methyl-2-benzophenone)-1-yl]-2-(dibenzothiophene ... [phenyl-4-yl]biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m DBTBPDBq-II) was evaporated to a film thickness of 15 nm, and then the above structural formula (vi) 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenyl- Phenothroline (abbreviation: NBPhen) was evaporated to a thickness of 10 nm, and an electron transport layer 114 was formed.

[0369] After forming the electron transport layer 114, lithium fluoride (LiF) was evaporated to a thickness of 1 nm. The electron injection layer 115 is formed by depositing aluminum to a thickness of 200 nm. The cathode 102 was formed by vapor deposition, and the light-emitting device 13 of this example was fabricated.

[0370] (Method of Making Light-Emitting Device 14) The light-emitting device 14 is a light-emitting device 13 in which BBA(βN)B is replaced with a compound having the above structural formula (xi ii) 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9 H-fluoren-9-yltriphenylamine (abbreviation: FLPAPA) It was fabricated in the same manner as optical device 13.

[0371] (Method of manufacturing light-emitting device 15) The light-emitting device 15 is a light-emitting device 13 in which BBA(βN)B is replaced with a compound having the above structural formula (xi v) N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1, 2-d]furan-8-amine (abbreviation: BnfABP) was used. It was made for you.

[0372] (Method of Making Light-Emitting Device 16) The light-emitting device 16 is a light-emitting device 13 in which BBA(βN2)B is replaced with a compound having the above structural formula (xv ) represented by 4-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]-4 ',4''-diphenyltriphenylamine (abbreviation: mpBBAFLBi) It was fabricated in the same manner as light-emitting device 13.

[0373] (Method of manufacturing light-emitting device 17) The light-emitting device 17 is a light-emitting device 13 in which BBA(βN2)B is replaced with a compound having the above structural formula (xv i) represented by N-[4-(9H-carbazol-9-yl)phenyl]-N-(1,1 '-biphenyl-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine( The light-emitting device was fabricated in the same manner as in device 13, except that the luminescent material was changed to YGBiSF.

[0374] (Method of Making Light-Emitting Device 18) The light-emitting device 18 is a light-emitting device 13 in which BBA(βN2)B is replaced with a compound having the above structural formula (xv ii) 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl] -4''-phenyltriphenylamine (abbreviation: TPBiAβNBi) It was fabricated in the same manner as Device 13.

[0375] (Method for fabricating light-emitting device 19) The light-emitting device 19 is a light-emitting device 13 in which BBA(βN2)B is replaced with a compound represented by the above structural formula (xv iii) 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl ) triphenylamine (abbreviation: BBAαNβNB-03) was used. was prepared in the same manner as above.

[0376] (Method of manufacturing light-emitting device 20) The light-emitting device 20 is a light-emitting device 13 in which BBA(βN)B is replaced with a compound having the above structural formula (xi x) 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]- The rest was changed to 4',4''-diphenyltriphenylamine (abbreviation: BBAFLBi). It was fabricated in the same manner as optical device 13.

[0377] The device structures of light-emitting devices 13 to 20 are summarized in the table below.

[0378] [Table 22]

[0379] In addition, the HOMO level, LUMO level, and electric field strength [V The table below summarizes the electron mobility when the square root of [μm / cm] is 600.

[0380] [Table 23]

[0381] These light-emitting devices were placed in a nitrogen atmosphere glove box, and the light-emitting devices were placed in a nitrogen atmosphere glove box. The process of sealing with a glass substrate to prevent exposure to heat (sealing material is applied around the element and sealed) After UV treatment at the time of shutdown and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices were The reliability and reliability were measured at room temperature.

[0382] The luminance vs. current density characteristics of the light-emitting devices 13 to 20 are shown in FIG. 68, and the current efficiency vs. luminance characteristics of the light-emitting devices 13 to 20 are shown in FIG. The brightness characteristics are shown in Figure 69, the brightness-voltage characteristics in Figure 70, the current-voltage characteristics in Figure 71, and the external quantum efficiency The efficiency-luminance characteristics are shown in Figure 72, and the emission spectra are shown in Figure 73. 00cd / m 2 The main characteristics in the vicinity are shown in Table 24. The numbers in the graph legend are It corresponds to the number of each light emitting device.

[0383] [Table 24]

[0384] 68 to 73 and Table 24, light-emitting devices 13 to 15 according to one embodiment of the present invention are shown. It was found that all of the devices 20 were blue light-emitting devices with good characteristics.

[0385] In addition, the current density is 50mA / cm 2 Figure 1 shows a graph showing the change in brightness over time. As shown in FIG. 74, light-emitting device 1, which is a light-emitting device according to one embodiment of the present invention, All of the light emitting elements 3 to 20 showed 90% or more of the initial luminance after 300 hours. The brightness remains at 95% or more, and the decrease in brightness due to the accumulated driving time is small, and the lifespan is good. It was found to be a useful light-emitting device.

[0386] <Reference example 1> In this reference example, the HOMO level, LUMO level and electron transfer A method for calculating the mobility will be described.

[0387] HOMO and LUMO levels are calculated based on cyclic voltammetry (CV) measurements. It is possible.

[0388] The measurement device used was an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model). The solution used in the CV measurements was dehydrated dimethyl ether. Dimethylformamide (DMF) (Aldrich Corporation, 99.8%, Catalog No. 227 05-6) was used, and the supporting electrolyte was tetra-n-butylammonium perchlorate (nB u4NClO4) (Tokyo Chemical Industry Co., Ltd., Catalog No.: T0836) at 100 mmol / The measurement target is dissolved in a solution to a concentration of 2 mmol / L. The working electrode was a platinum electrode (PT, manufactured by BAS Co., Ltd.). E platinum electrode), and as an auxiliary electrode, a platinum electrode (B.A.S. Co., Ltd., VC-3 P The counter electrode (5 cm) was used as the reference electrode, and Ag / Ag + Electrode (B.A.E. The measurements were carried out at room temperature (20 to 32°C). The scan rate during CV measurement was standardized to 0.1 V / sec. The oxidation potential Ea [V] and reduction potential Ec [V] were measured against the reference electrode. The potential of the reduction wave is defined as the midpoint potential of the reduction wave, and Ec is defined as the midpoint potential of the reduction-oxidation wave. The potential energy of the reference electrode relative to the vacuum level is -4.94 eV. Since it is known that the HOMO level [eV] = -4.94-Ea, the LUMO level [eV ]=-4.94-Ec, calculate the HOMO and LUMO levels. It is possible.

[0389] Electron mobility was measured by impedance spectroscopy (Impedance Spectroscopy) It can be measured using the IS method.

[0390] The carrier mobility of EL materials is measured by the transient photocurrent method (Time-of-flight: T OF method and space-charge-limited current The SCLC method, which uses the IV characteristics of the SCLC (internal voltage: SCLC), has been known for a long time. The TOF method requires a sample with a significantly thicker film than an actual organic EL element. The LC method has the disadvantage that the dependence of carrier mobility on electric field strength cannot be obtained. The thickness of the organic film required for measurement is only a few hundred nanometers, so even a relatively small amount of EL material can be used. It is possible to form a film, and the mobility can be measured at a film thickness close to that of an actual EL element. and the electric field strength dependence of the carrier mobility can also be obtained.

[0391] In the IS method, a minute sinusoidal voltage signal (V = V0 [exp(jωt)]) is applied to the EL element, The current amplitude of the response current signal (I = I0exp[j(ωt+φ)]) and the phase of the input signal The difference is used to calculate the impedance of the EL element (Z=V / I). If the applied voltage is varied from 100 to 1000 V, the impedance will be varied. The components can be separated and measured.

[0392] Here, the admittance Y (=1 / Z), which is the reciprocal of the impedance, is expressed as follows: It can be expressed as conductance G and susceptance B as follows:

[0393]

number

[0394] Furthermore, by the single charge injection model, The following equations (2) and (3) can be calculated: where g (equation (4)) is the differential conductance. In the formula, C is the capacitance, θ is the travel angle, and ω represents the angular frequency. t is the transit time. The analysis uses the current equation, Poisson's equation, and current continuity equation. The equation below is used, ignoring the existence of diffusion current and trap levels.

[0395]

number

[0396] The -ΔB method is a method for calculating mobility from the frequency characteristics of capacitance. The ωΔG method is a method for calculating the mobility from the frequency characteristics of the carrier.

[0397] In practice, first, an electron-only device is fabricated from the material whose electron mobility is to be determined. A junction element is an element designed to allow only electrons to flow as carriers. This section explains the method for calculating the mobility from the frequency characteristics of the capacitance (-ΔB method). A schematic diagram of a child-only element is shown in FIG.

[0398] The structure of the electron-only device fabricated for this measurement is shown in Figure 42, which consists of an anode 201 and The cathode 202 is provided with a first layer 210, a second layer 211, and a third layer 212. The material for which the mobility is to be determined can be used as the material for the second layer 211. Explain the example of measuring the electron mobility of a 1:1 (weight ratio) co-evaporated film of q. Specific configuration examples are summarized in the table below.

[0399] [Table 25]

[0400] Current density of electron-only devices fabricated using a co-evaporated film of ZADN and Liq as the second layer 211 The temperature-voltage characteristics are shown in FIG.

[0401] The impedance measurement was performed by applying a DC voltage in the range of 5.0V to 9.0V while applying an AC voltage. The measurement was carried out under the conditions of a voltage of 70 mV and a frequency of 1 Hz to 3 MHz. The capacitance is calculated from the admittance (equation (1) above), which is the reciprocal of the impedance. The frequency characteristics of the calculated capacitance C at an applied voltage of 7.0 V are shown in FIG.

[0402] The frequency characteristics of capacitance C are the space charge due to carriers injected by a minute voltage signal. This is because the load cannot completely follow the minute AC voltage, and a phase difference occurs in the current. Here, the transit time of the carriers in the film is the time T for the injected carriers to reach the counter electrode. It is defined and expressed by the following equation (5).

[0403]

number

[0404] The negative susceptance change (-ΔB) is the capacitance change -ΔC multiplied by the angular frequency ω (-ωΔ C) The lowest frequency peak frequency f' max (=ω max / 2π) and From equation (3), the relationship between the row time T and equation (6) below is derived.

[0405]

number

[0406] The frequency characteristics of -ΔB calculated from the above measurement (i.e., when the DC voltage is 7.0 V) are shown in Fig. 4. 5. The lowest frequency peak frequency f' obtained from Figure 45 max is indicated by the arrow in the figure. did.

[0407] f' obtained from the above measurements and analysis max From this, the travel time T can be calculated (the above formula ( 6), and from the above formula (5), in this case, the electron mobility at a DC voltage of 7.0 V is calculated. By performing similar measurements in the DC voltage range of 5.0V to 9.0V, Since the electron mobility can be calculated at different voltages (electric field strength), the dependence of mobility on electric field strength can also be measured. do.

[0408] Using the above calculation method, the electric field strength dependence of the electron mobility finally obtained for each organic compound was The square root of the electric field strength [V / cm] read from the figure is 600 [V / cm]. 1 / 2 The electron mobility values ​​at these times are shown in Table 26.

[0409] [Table 26]

[0410] As described above, it is possible to calculate the electron mobility. , Takayuki Okachi et al. ”Japanese Journal of Applied Physics” Vol. 47, No. 12, 2008, See pp. 8965-8972.

[0411] <Reference example 2> In this Reference Example, methods for synthesizing the organic compounds used in the Examples will be described.

[0412] <Synthesis Example 1: 4-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]-4 Synthesis method of ',4''-diphenyltriphenylamine (abbreviation: mpBBAFLBi)≫ The structural formula of mpBBAFLBi is shown below.

[0413] [ka]

[0414] In a 200 mL three-neck flask, add 9-(3-bromophenyl)-9-phenyl-9H-fluoro 2.0 g (5.0 mmol), 2-{4-[di(4-biphenylyl)amino]phenyl 2.6 g (5. 0mmol), tri(ortho-tolyl)phosphine 30mg (0.10mmol), carbonate 2.8 g (20 mmol) of potassium was added, and the atmosphere in the flask was replaced with nitrogen. Add 15 mL of toluene, 10 mL of ethanol, and 10 mL of water, and degas by stirring under reduced pressure. To this mixture was added 11 mg (0.050 mmol) of palladium (II) acetate, and the mixture was heated under nitrogen. The mixture was stirred under airflow at 80°C for 2 hours.

[0415] After stirring, the mixture was filtered under suction to recover the solid, which was dissolved in hot toluene and The filtrate was concentrated and the resulting solid was filtered through Celite, alumina, and Florisil. The product was recrystallized from toluene to give 2.7 g of the desired white solid in 74% yield. The synthesis scheme of the above synthesis method is shown below.

[0416] [ka]

[0417] The resulting white solid (2.6 g) was purified by train sublimation. The white solid was heated to 280°C under the conditions of a pressure of 3.5 Pa and an argon flow rate of 5.0 mL / min. After purification by sublimation, 2.3 g of a pale yellow solid was obtained with a recovery rate of 88%.

[0418] Nuclear magnetic resonance spectroscopy ( 1 The results of analysis by 1 H NMR are shown below. This result confirmed that mpBBAFLBi was obtained. 1 H NMR(DMSO,300MHz):δ=7.06-7.49(m, 29H),7 .59-7.64(m,8H),7.90(d,J=7.8Hz,2H).

[0419] <Synthesis Example 2: 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4 Synthesis method of ''-phenyltriphenylamine (abbreviation: TPBiAβNBi)'' The structural formula of TPBiAβNBi is shown below.

[0420] [ka]

[0421] Step 1: N-(1,1'-biphenyl)-4-yl-(1,1':4',1''- Synthesis of 4-terphenyl-4-amine 2.4 g (7.4 mmol) of N-(4-bromophenyl)-4-biphenylamine, 1.5 g (7.4 mmol) of 4-biphenylboronic acid and 47 mg (0.15 mmol) ) tri(ortho-tolyl)phosphine and 7 mL of aqueous potassium carbonate (2.0 mol / L), 60 mL of toluene, and 20 mL of ethanol were added to a 200 mL The mixture was placed in a three-neck flask, degassed under reduced pressure, and then the atmosphere in the system was replaced with nitrogen. To the mixture was added 16 mg (74 μmol) of palladium(II) acetate, and the mixture was refluxed for 3 hours. The precipitated solid was then collected by suction filtration, and the resulting solid was dissolved in toluene, ethanol, and water. After washing with water, 2.94 g of the desired gray solid was obtained in a yield of over 99%. The synthesis scheme is shown below.

[0422] [ka]

[0423] <Step 2: Synthesis of 2-(4-chloro-biphenyl-4-yl)naphthalene> 2.4 g (10 mmol) of 1-chloro-4-iodobenzene and 2.5 g (10 mmol) l) 4-(2-naphthyl)phenylboronic acid and 61 mg (0.20 mmol) of trimethylsilyl (ortho-tolyl)phosphine and 20 mL of aqueous potassium carbonate (2.0 mol / L) 70 mL of toluene and 30 mL of ethanol were placed in a 200 mL three-neck flask equipped with a reflux condenser. The solvent was degassed under reduced pressure and the inside of the container was replaced with nitrogen. Add 22 mg (0.10 mmol) of palladium (II) and stir at 50°C for 3 hours. After stirring, the precipitated solid was collected by suction filtration, and toluene, water, and ethanol were added. After washing with HCl, 2.7 g of a brown solid was obtained in 86% yield. The team is shown below.

[0424] [ka]

[0425] Nuclear magnetic resonance spectroscopy ( 1 The results of analysis by 1 H NMR are shown below. As a result, 2-(4-chloro-biphenyl-4-yl)naphthalene was obtained by the above synthesis steps. It turns out that Len was obtained. 1 H NMR (dichloromethane-d2, 500 MHz): δ = 8.13 (s, 1H), 7 .96(d,J=9.5Hz,1H),7.94(d,J=9.5Hz,1H),7.8 9(d,J=7.0Hz,1H),7.85-7.81(m,3H),7.72(d,J =8.0Hz,2H),7.64(d,J=8.5Hz,2H),7.55-7.49( m, 2H), 7.46 (d, J = 8.0 Hz, 2H).

[0426] Step 3: 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]- Synthesis of 4''-phenyltriphenylamine (TPBiAβNBi) 2.94 g (7.4 mmol) of N-(1,1'-biphenyl)- obtained in Step 1 Step 2: 4-yl-(1,1':4',1''-terphenyl)-4-4-amine 2.32 g (7.4 mmol) of 2-(4-chloro-biphenyl-4-yl) Naphthalene and 52 mg (0.15 mmol) of di-tert-butyl(1-methyl-2 ,2-diphenylcyclopropyl)phosphine (trade name: cBRIDP (registered trademark)) , 1.4g (15mmol) sodium tert-butoxide and 140mL xylene The mixture was degassed under reduced pressure and then cooled to 100°C. The resulting mixture was purged with nitrogen. Palladium (0) in acetone was added and refluxed for 5 hours. After stirring, the precipitated solid was collected by suction filtration. The solid was collected by filtration and washed with toluene, water, and ethanol to give 3.8 g of a gray solid. The synthesis scheme for step 3 is shown below.

[0427] [ka]

[0428] The resulting solid (3.8 g) was purified by train sublimation. The solid was heated at 335°C under a pressure of 3.8 Pa for 15 hours while argon was flowing at 15 mL / min. After purification by sublimation, 2.8 g of the target pale yellow solid was obtained with a recovery rate of 74%.

[0429] Nuclear magnetic resonance spectroscopy of the obtained solid ( 1 The results of analysis by 1 H NMR are shown below. From this, it was found that TPBiAβNBi was obtained in this synthesis example. 1 H NMR (chloroform-d, 500 MHz): δ = 8.10 (d, J = 1.5 Hz ,1H),7.94(d,J=9.0Hz,1H),7.92(d,J=7.5Hz,1 H),7.88(d,J=7.5Hz,1H),7.82-7.80(m,3H),7. 73(d,J=8.5Hz,2H),7.68(s,4H),7.66(d,J=7.0 Hz,2H),7.62-7.58(m,6H),7.55(d,J=8.5Hz,2H ),7.52-7.43(m,6H),7.36(t,J=7.0Hz,1H),7.3 3(t,J=7.0Hz,1H),7.29-7.27(m,6H).

[0430] <<Synthesis Example 3: 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-4 Synthesis method of ',4''-diphenyltriphenylamine (abbreviation: BBAFLBi)≫ The structural formula of BBAFLBi is shown below.

[0431] [ka]

[0432] Step 1: 4-(9-phenyl-9H-fluoren-9-yl)phenylboronic acid Synthesis> In a 500 mL three-neck flask, 15.89 g (40 mmol) of 9-(4-bromo-2-methyl-2-propanol) After adding (phenyl)-9-phenyl-9H-fluorene, degas the mixture by reducing the pressure. The inside of the vessel was replaced with nitrogen. 200 ml of dehydrated tetrahydrofuran (abbreviation: THF) was added to the vessel. The mixture was cooled to about -78°C with stirring, and then 1.59 mol / Add 30 mL (48 mmol) of n-butyllithium hexane solution dropwise and keep the temperature at -40°C. After the temperature was raised, the mixture was stirred for 1 hour. After that, 50 mL of dehydrated THF was added, and the temperature was again adjusted to about -78 After cooling to ° C., 6.4 mL (57 mmol) of trimethyl borate was added dropwise. The mixture was allowed to warm to room temperature and then stirred for 16 hours. After adding 30 mL of hydrochloric acid and stirring, the aqueous layer and the organic layer were separated, and the resulting organic layer was diluted with saturated sodium bicarbonate water. The mixture was washed once with 100 mL of saturated saline and once with 100 mL of sodium chloride. After drying over sodium and concentrating, the mixture was recrystallized from toluene to give 10.1 g of a white solid. The yield was 70%. The synthesis scheme for Step 1 is shown below.

[0433] [ka]

[0434] <Step 2: Synthesis of BBAFLBi> In a 200 mL three-neck flask, 2.53 g (7 mmol) of 4-(9-phenyl-9 H-fluoren-9-yl)phenylboronic acid and 3.34 g (7 mmol) of 4-bromo mo-4',4''-diphenyltriphenylamine and 2.90 g (7 mmol) of carbonate Potassium, 70 mL of toluene, 12.5 mL of ethanol, and 10.5 mL of water were added. This mixture was degassed by stirring under reduced pressure, and the atmosphere in the flask was replaced with nitrogen. The mixture contained 15.7 mg (0.07 mmol) of palladium(II) acetate and 42.2 mg (0 Tris(o-tolyl)phosphine (0.07 mmol) was added, and the mixture was heated at 85°C for 6 hours under a nitrogen stream. After the mixture was allowed to cool to room temperature, the precipitated solid was filtered off, and the resulting solution was The filtrate was washed twice with 100 mL of water and once with 50 mL of saturated saline, and then added magnesium sulfate. This was combined with the solid that had been filtered out after the reaction and diluted with toluene for 30 minutes. Add 0 mL of HCl, heat to dissolve the solid, then add Celite / Alumina / Florisil The filtrate was concentrated and recrystallized by adding ethanol. The synthesis scheme for Step 2 is shown below. vinegar.

[0435] [ka]

[0436] The resulting white solid (4.39 g) was purified by train sublimation. The product was heated at 320°C under the conditions of a pressure of 3.5 Pa and an argon flow rate of 15 mL / min. After sublimation purification, 2.73 g of white solid BBAFLP was obtained with a recovery rate of 62%. .

[0437] Nuclear magnetic resonance spectroscopy ( 1 The results of analysis by 1 H NMR are shown below. From the results, it was found that BBAFLP was obtained in this synthesis example. 1 H NMR (CDCl3,500MHz):δ=7.17-7.28(m,13H),δ=7.31 (dd,J=12.6Hz,7.4Hz,4H),δ=7.37(dd,J=7.5Hz ,1.1Hz,4H),δ=7.40-7.47(m,10H),δ=7.51(d,J =8.6Hz,4H)δ=7.58(d,J=8.1Hz,4H)δ=7.78(d,J =7.4Hz,2H).

[0438] Synthesis Example 4: N-[4-(9H-carbazol-9-yl)phenyl]-N-(1,1' -biphenyl-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation Name: oYGBiSF) synthesis method≫ The structural formula of oYGBiSF is shown below.

[0439] [ka]

[0440] <Step 1: N-(1,1'-biphenyl-2-yl)-9,9'-spirobi[9H- Synthesis of fluorene-2-amine 1.8 g (10 mmol) of 2-aminobiphenyl and 4.1 g (10 mmol) of 2- Bromo-9,9'-spirobi[9H-fluorene], 0.34g (0.80mmol) 2-Dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: SP hos) and 2.0 g (20 mmol) of sodium t-butoxide were placed in a condenser and a three-way The mixture was placed in a 200 mL three-neck flask fitted with a stopper and a ground stopper, and the inside of the system was replaced with nitrogen. After degassing the mixture under reduced pressure, the system was placed under a nitrogen stream, and the mixture was The mixture was heated to 60°C and stirred. After the temperature in the system reached 60°C, 0.24 g (0.40 mmol) of bicarbonate was added. Bis(dibenzylideneacetone)palladium(0) was added, and the mixture was then heated at 80°C for 2 After heating and stirring, the precipitated solid was removed by suction filtration, and the obtained filtrate The mixture was washed three times with water and then with saturated saline, and the organic layer was dried over magnesium sulfate. The filtrate was filtered by gravity and concentrated to give 3.4 g of a brown solid. Gel column chromatography (mobile phase: hexane:toluene = 10:1 to 2:1) The resulting solid was purified by a gradient elution method to obtain the desired white solid. The product was recrystallized from toluene / hexane to give 3.7 g of a white solid in 74% yield. The synthesis scheme for Step 1 is shown below.

[0441] [ka]

[0442] Step 2: N-[4-(9H-carbazol-9-yl)phenyl]-N-(1,1 '-biphenyl-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine( Synthesis of oYGBiSF 2.7 g (5.5 mmol) of N-(1,1'-biphenyl-2-yl) )-9,9'-spirobi[9H-fluorene]-2-amine and 1.8 g (5.5 mmol) l) 9-(4-bromophenyl)-9H-carbazole and 0.18 g (0.40 mm ol) 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: S-Phos) and 1.1 g (11 mmol) of sodium t-butoxide were placed in a condenser and The mixture was placed in a 200 mL three-neck flask equipped with a stopcock and a ground stopper, and the atmosphere in the system was replaced with nitrogen. 2 mL of toluene was added. After degassing the mixture under reduced pressure, the system was placed under a nitrogen stream. To the mixture was added 0.13 g (0.22 mmol) of bis(dibenzylideneacetone)palladium ( 0) was added, and then the mixture was heated and stirred at 80°C. After heating and stirring, the precipitated solid was absorbed. The filtrate was washed three times with water and then with saturated saline, and the organic layer was After drying, the mixture was gravity filtered and the filtrate was concentrated to give a brown solid. The resulting brown solid was purified by silica gel column chromatography (mobile phase: hexane:toluene The desired white product was purified by a gradient of 10:1 to 2:1. The solid was recrystallized from toluene / hexane to give the target white solid. was obtained in 3.2 g with a yield of 79%.

[0443] The obtained white solid was purified by train sublimation. 3.2 g of white solid was heated at 310°C under 2.9 Pa and argon at 15 mL / min. After sublimation purification, 2.9 g of the target colorless transparent cubic crystal was obtained, with a recovery rate of 91%. The synthesis scheme for Step 2 is shown below.

[0444] [ka]

[0445] The obtained solid 1 H-NMR measurements were carried out. The results are shown below. In the example, it was found that oYGBiSF was obtained. 1 H NMR (dichloromethane-d2, 500 MHz): δ = 6.29 (sd, J2 = 2 .0Hz, 1H), 6.56(d, J=7.5Hz, 1H), 6.67(d, J=7.5 Hz, 2H), 6.86(dt, J1=9.0Hz, J2=2.0Hz, 2H), 6.9 3(dd, J1=8.3Hz, J2=2.0Hz, 1H), 7.00(td, J1=7. 5Hz, J2=1.0Hz, 1H), 7.04-7.08(m, 5H), 7.08-7. 11(m, 2H), 7.14(td, J1=7.5Hz, J2=1.0Hz, 2H), 7 .21-7.31(m, 9H), 7.34(td, J1=7.0Hz, J2=1.5Hz , 2H), 7.38(td, J1=7.5Hz, J2=1.0Hz, 2H), 7.59( d, J=8.0Hz, 1H), 7.70(d, J=8.0Hz, 1H), 7.79(d, J=8.0Hz, 2H), 8.09(d, J=8.0Hz, 2H). [Explanation of symbols]

[0446] 101 Anode 102 Cathode 103 EL layer 111 Hole injection layer 112 Hole transport layer 112-1 First hole transport layer 112-2 Second hole transport layer 113 Light-emitting layer 114 Electron transport layer 115 Electron injection layer 116 Charge generation layer 117 P type layer 118 Electronic Relay Layer 119 Electron injection buffer layer 201 Anode 202 Cathode 210 First Layer 211 Second Layer 212 Third Layer 400 boards 401 Anode 403 EL layer 404 Cathode 405 Sealing material 406 Sealing material 407 Sealing substrate 412 Pad 420 IC chip 501 Anode 502 Cathode 511 First Light Emitting Unit 512 Second Light Emitting Unit 513 Charge generation layer 601 Driver circuit section (source line driver circuit) 602 Pixel section 603 Drive circuit section (gate line drive circuit) 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 Element substrate 611 Switching FET 612 Current control FET 613 Anode 614 Insulators 616 EL layer 617 Cathode 618 Light-emitting devices 951 PCB 952 Electrode 953 Insulation Layer 954 Partition layer 955 EL layer 956 Electrode 1001 board 1002 Undercoat insulating film 1003 Gate insulating film 1006 Gate electrode 1007 Gate electrode 1008 gate electrode 1020 First interlayer insulating film 1021 Second interlayer insulating film 1022 Electrode 1024W anode 1024R Anode 1024G anode 1024B Anode 1025 Bulkhead 1028 EL layer 1029 Cathode 1031 Sealing substrate 1032 Sealing material 1033 Transparent substrate 1034R Red color layer 1034G Green color layer 1034B Blue color layer 1035 Black Matrix 1036 Overcoat layer 1037 Third interlayer insulating film 1040 pixel section 1041 Drive circuit section 1042 Periphery 2001 Case 2002 light source 2100 Robot 2110 Arithmetic equipment 2101 Illuminance sensor 2102 Microphone 2103 Upper Camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 3001 Lighting equipment 5000 cabinets 5001 Display section 5002 Second display unit 5003 Speaker 5004 LED lamp 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning Robot 5101 Display 5102 Camera 5103 Brush 5104 Operation button 5150 Personal Digital Assistant 5151 Case 5152 Display area 5153 Bend 5120 Garbage 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 Housing 7103 Display section 7105 Stand 7107 Display section 7109 Operation key 7110 Remote control device 7201 Main unit 7202 Case 7203 Display section 7204 keyboard 7205 External connection port 7206 Pointing Device 7210 Second display unit 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 Housing

Claims

1. It has an anode, a first layer, a second layer, a third layer, a light-emitting layer, a fourth layer, and a cathode. The first layer is located between the anode and the second layer. The second layer is located between the first layer and the third layer. The third layer is located between the second layer and the light-emitting layer. The light-emitting layer is located between the third layer and the fourth layer. The fourth layer is located between the light-emitting layer and the cathode. The first layer of the invention comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer comprises a fifth organic compound and a sixth organic compound, The sixth organic compound is an organic compound having an anthracene skeleton and a heterocyclic skeleton, The fourth layer has a seventh organic compound, The first organic compound is an organic compound having a halogen group, The second organic compound has a carbazole skeleton, The fifth organic compound is a luminescent central substance, The second organic compound and the third organic compound are the same substance. The HOMO level of the second organic compound is between -5.7 eV and -5.2 eV. The HOMO level of the fourth organic compound is the same as, or deeper than, the HOMO level of the third organic compound. The difference between the HOMO level of the fourth organic compound and the HOMO level of the third organic compound is 0.2 eV or less. The third organic compound is different from the fourth organic compound, and is a light-emitting device.

2. It has an anode, a first layer, a second layer, a third layer, a light-emitting layer, a fourth layer, and a cathode. The first layer is located between the anode and the second layer. The second layer is located between the first layer and the third layer. The third layer is located between the second layer and the light-emitting layer. The light-emitting layer is located between the third layer and the fourth layer. The fourth layer is located between the light-emitting layer and the cathode. The first layer of the invention comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer comprises a fifth organic compound and a sixth organic compound, The sixth organic compound is an organic compound having an anthracene skeleton and a heterocyclic skeleton, The fourth layer has a seventh organic compound, The first organic compound is an organic compound having a halogen group, The second organic compound has a carbazole skeleton, The fifth organic compound is a luminescent central substance, The second organic compound and the third organic compound are the same substance. The HOMO level of the second organic compound is between -5.7 eV and -5.2 eV. The LUMO level of the sixth organic compound is shallower than the LUMO level of the seventh organic compound. The HOMO level of the fourth organic compound is the same as, or deeper than, the HOMO level of the third organic compound. The difference between the HOMO level of the fourth organic compound and the HOMO level of the third organic compound is 0.2 eV or less. The third organic compound is different from the fourth organic compound, and is a light-emitting device.

3. It has an anode, a first layer, a second layer, a third layer, a light-emitting layer, a fourth layer, and a cathode. The first layer is located between the anode and the second layer. The second layer is located between the first layer and the third layer. The third layer is located between the second layer and the light-emitting layer. The light-emitting layer is located between the third layer and the fourth layer. The fourth layer is located between the light-emitting layer and the cathode. The first layer of the invention comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer comprises a fifth organic compound and a sixth organic compound, The sixth organic compound is an organic compound having an anthracene skeleton and a heterocyclic skeleton, The fourth layer has a seventh organic compound, The first organic compound is an organic compound having a halogen group, The second organic compound has a carbazole skeleton, The fifth organic compound is a luminescent central substance, The second organic compound and the third organic compound are the same substance. The HOMO level of the second organic compound is between -5.7 eV and -5.2 eV. The LUMO level of the sixth organic compound is shallower than the LUMO level of the seventh organic compound. The difference between the LUMO level of the seventh organic compound and the LUMO level of the sixth organic compound is 0.1 eV or more and 0.3 eV or less. The HOMO level of the fourth organic compound is the same as, or deeper than, the HOMO level of the third organic compound. The difference between the HOMO level of the fourth organic compound and the HOMO level of the third organic compound is 0.2 eV or less. The third organic compound is different from the fourth organic compound, and is a light-emitting device.

4. It has an anode, a first layer, a second layer, a third layer, a light-emitting layer, a fourth layer, and a cathode. The first layer is located between the anode and the second layer. The second layer is located between the first layer and the third layer. The third layer is located between the second layer and the light-emitting layer. The light-emitting layer is located between the third layer and the fourth layer. The fourth layer is located between the light-emitting layer and the cathode. The first layer of the invention comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer comprises a fifth organic compound and a sixth organic compound, The sixth organic compound is an organic compound having an anthracene skeleton and a heterocyclic skeleton, The fourth layer has a seventh organic compound, The first organic compound is an organic compound having a halogen group, The second organic compound has a carbazole skeleton, The fifth organic compound is a luminescent central substance, The second organic compound and the third organic compound are the same substance. The HOMO level of the second organic compound is between -5.7 eV and -5.2 eV. The seventh organic compound is an organic compound having one of the following: a quinoxaline skeleton, a benzimidazole skeleton, and a triazine skeleton. The HOMO level of the fourth organic compound is the same as, or deeper than, the HOMO level of the third organic compound. The difference between the HOMO level of the fourth organic compound and the HOMO level of the third organic compound is 0.2 eV or less. The third organic compound is different from the fourth organic compound, and is a light-emitting device.

5. It has an anode, a first layer, a second layer, a third layer, a light-emitting layer, a fourth layer, and a cathode. The first layer is located between the anode and the second layer. The second layer is located between the first layer and the third layer. The third layer is located between the second layer and the light-emitting layer. The light-emitting layer is located between the third layer and the fourth layer. The fourth layer is located between the light-emitting layer and the cathode. The first layer of the invention comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer comprises a fifth organic compound and a sixth organic compound, The sixth organic compound is an organic compound having an anthracene skeleton and a heterocyclic skeleton, The fourth layer has a seventh organic compound, The first organic compound is an organic compound having a halogen group, The second organic compound has a carbazole skeleton, The fifth organic compound is a luminescent central substance, The second organic compound and the third organic compound are the same substance. The HOMO level of the second organic compound is between -5.7 eV and -5.2 eV. The seventh organic compound is an organic compound having one of the following: a quinoxaline skeleton, a benzimidazole skeleton, and a triazine skeleton. The LUMO level of the sixth organic compound is shallower than the LUMO level of the seventh organic compound. The HOMO level of the fourth organic compound is the same as, or deeper than, the HOMO level of the third organic compound. The difference between the HOMO level of the fourth organic compound and the HOMO level of the third organic compound is 0.2 eV or less. The third organic compound is different from the fourth organic compound, and is a light-emitting device.

6. It has an anode, a first layer, a second layer, a third layer, a light-emitting layer, a fourth layer, and a cathode. The first layer is located between the anode and the second layer. The second layer is located between the first layer and the third layer. The third layer is located between the second layer and the light-emitting layer. The light-emitting layer is located between the third layer and the fourth layer. The fourth layer is located between the light-emitting layer and the cathode. The first layer of the invention comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer comprises a fifth organic compound and a sixth organic compound, The sixth organic compound is an organic compound having an anthracene skeleton and a heterocyclic skeleton, The fourth layer has a seventh organic compound, The first organic compound is an organic compound having a halogen group, The second organic compound has a carbazole skeleton, The fifth organic compound is a luminescent central substance, The second organic compound and the third organic compound are the same substance. The HOMO level of the second organic compound is between -5.7 eV and -5.2 eV. The seventh organic compound is an organic compound having one of the following: a quinoxaline skeleton, a benzimidazole skeleton, and a triazine skeleton. The LUMO level of the sixth organic compound is shallower than the LUMO level of the seventh organic compound. The difference between the LUMO level of the seventh organic compound and the LUMO level of the sixth organic compound is 0.1 eV or more and 0.3 eV or less. The HOMO level of the fourth organic compound is the same as, or deeper than, the HOMO level of the third organic compound. The difference between the HOMO level of the fourth organic compound and the HOMO level of the third organic compound is 0.2 eV or less. The third organic compound is different from the fourth organic compound, and is a light-emitting device.

7. In any one of claims 1 to 6, The light-emitting device wherein the fourth organic compound is an aromatic monoamine containing a naphthalene ring, an aromatic amine containing a dibenzofuran ring, or an aromatic amine containing a dibenzothiophene ring.

8. In any one of claims 1 to 6, The light-emitting device wherein the fourth organic compound is an aromatic monoamine containing a naphthalene ring or an aromatic amine containing a dibenzothiophene ring.

9. In any one of claims 1 to 6, The fourth organic compound is an aromatic monoamine containing a naphthalene ring, in the light-emitting device.

10. In any one of claims 1 to 9, The second organic compound has a first hole-transporting skeleton, The third organic compound has a second hole-transporting skeleton, The fourth organic compound has a third hole-transporting skeleton, A light-emitting device in which the first hole-transporting skeleton, the second hole-transporting skeleton, and the third hole-transporting skeleton are each independently one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton.

11. In any one of claims 1 to 10, A light-emitting device in which the difference between the HOMO level of the fourth organic compound and the HOMO level of the sixth organic compound is less than 0.2 eV.

12. In any one of claims 1 to 11, The fifth organic compound is a blue fluorescent material, which is used in the light-emitting device.

13. In any one of claims 1 to 12, The fourth layer has the function of an electron transport layer, The electron transport layer is in contact with the light-emitting layer in a light-emitting device.

14. An electronic device comprising a light-emitting device according to any one of claims 1 to 13, and a sensor, an operating button, a speaker, or a microphone.

15. A light-emitting device comprising a light-emitting device according to any one of claims 1 to 13, and a transistor or a substrate.

16. A lighting device comprising a light-emitting device according to any one of claims 1 to 13, and a housing.

Images