Light-emitting device

Abstract

To provide a light-emitting device with excellent reliability.SOLUTION: A light-emitting device has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a substance that can convert triplet excitation energy into light emission. The first organic compound has a π-electron deficient type heteroaromatic ring. The second organic compound has a π-electron excess type heteroaromatic ring or an aromatic amine skeleton. The first organic compound and the second organic compound contain deuterium. A difference between the lowest triplet excitation level of the first organic compound and the lowest triplet excitation level of the second organic compound is 0.10 eV or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, an organic semiconductor device, a light-emitting device, a photodiode sensor, a display module, a lighting module, a display device, an electronic device, a lighting device, and an electronic device. Note that one aspect of the present invention is not limited to the above technical field. The technical field of one aspect of the invention disclosed in this specification and the like relates to an article, a method, or a manufacturing method. Alternatively, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one aspect of the present invention disclosed in this specification include semiconductor devices, display devices, liquid crystal display devices, lighting devices, power storage devices, storage devices, imaging devices, driving methods thereof, or manufacturing methods thereof.

Background Art

[0002] The practical application of light-emitting devices (also referred to as organic EL devices) that utilize electroluminescence (EL) using organic compounds has been progressing. The basic configuration of these light-emitting devices is such that an organic compound layer containing a light-emitting material is sandwiched between a pair of electrodes. By applying a voltage to this device to inject carriers and utilizing the recombination energy of the carriers, light emission from the light-emitting material can be obtained.

[0003] Since the light-emitting device is self-luminous, a display device using the light-emitting device as a pixel has higher visibility than a liquid crystal display device and does not require a backlight. In addition, a display device using such a light-emitting device can be manufactured to be thin and lightweight, which is also a great advantage. Furthermore, it is also characterized by a very fast response speed.

[0004] In addition, since these light-emitting devices can form a light-emitting layer continuously in a planar shape, planar light emission can be obtained. This is a characteristic that is difficult to achieve with point light sources typified by incandescent bulbs and LEDs, or line light sources typified by fluorescent lamps, so it also has high utility value as a surface light source that can be applied to lighting and the like.

[0005] As described above, display devices and lighting devices using such light-emitting devices are suitable for various electronic devices, and research and development are being advanced to obtain light-emitting devices having better characteristics.

[0006] Patent Document 1 discloses a light-emitting device in which a metal complex is paired with a deuterated host to delay the decomposition mechanism that deteriorates the metal complex, thereby improving reliability.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] An object of one aspect of the present invention is to provide a light-emitting device having good characteristics. Or, an object of one aspect of the present invention is to provide a light-emitting device having good reliability. Or, an object of one aspect of the present invention is to provide a light-emitting device having a low driving voltage. Or, an object of one aspect of the present invention is to provide a light-emitting device having good reliability and a low driving voltage.

[0009] Alternatively, in one aspect of the present invention, an object is to provide a light-emitting device capable of providing a display device with good characteristics. Alternatively, in one aspect of the present invention, an object is to provide a light-emitting device capable of providing a display device with good reliability. Alternatively, in one aspect of the present invention, an object is to provide a display device with a low driving voltage. Alternatively, in one aspect of the present invention, an object is to provide a light-emitting device capable of providing a display device with a low driving voltage and good reliability. Alternatively, in one aspect of the present invention, an object is to provide an organic compound suitable for the above light-emitting device.

[0010] Alternatively, an object is to provide any one of an organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device with low power consumption. Alternatively, an object is to provide either a highly reliable electronic device or a lighting device.

[0011] The present invention only needs to solve any one of the above problems.

Means for Solving the Problems

[0012] One aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission. The first organic compound has a π-electron-deficient heteroaromatic ring, and the second organic compound has a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton. The first organic compound and the second organic compound contain deuterium, and the difference between the lowest triplet excitation level of the first organic compound and the lowest triplet excitation level of the second organic compound is 0.20 eV or less.

[0013] Another aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission. The first organic compound has a π-electron-deficient heteroaromatic ring, the second organic compound has a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton. The first organic compound and the second organic compound contain deuterium, and the first organic compound and the second organic compound are a combination that forms an exciplex. It is a light-emitting device in which the emission spectrum of the exciplex overlaps with the emission spectrum of the substance capable of converting triplet excitation energy into light emission.

[0014] Another aspect of the present invention is a light-emitting device in the above configuration, wherein the difference between the maximum peak wavelength of the emission spectrum of the exciplex and the maximum peak wavelength of the emission spectrum of the substance capable of converting triplet excitation energy into light emission is 30 nm or less.

[0015] Alternatively, another aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission. The first organic compound has a π-electron-deficient heteroaromatic ring, the second organic compound has a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton. The first organic compound and the second organic compound contain deuterium. The phosphorescence emission lifetime or delayed fluorescence lifetime of the first organic compound at 77 K is 1.20 times or more the phosphorescence emission lifetime or delayed fluorescence lifetime of a third organic compound in which the deuterium of the first organic compound is hydrogen at 77 K, and the phosphorescence emission lifetime or delayed fluorescence lifetime of the second organic compound at 77 K is 1.05 times or more the phosphorescence emission lifetime or delayed fluorescence lifetime of a fourth organic compound in which the deuterium of the second organic compound is hydrogen at 77 K. It is a light-emitting device.

[0016] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the peak wavelength of the emission spectrum in the light emitted by the substance capable of converting triplet excitation energy into light emission is 450 nm or more and less than 500 nm. Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the peak wavelength of the emission spectrum in the light emitted by the substance capable of converting triplet excitation energy into light emission is more than 600 nm and 700 nm or less.

[0017] Alternatively, another aspect of the present invention is a light-emitting device having a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission. The first organic compound has a π-electron-deficient heteroaromatic ring, and the second organic compound has a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton. The first organic compound and the second organic compound contain deuterium. The phosphorescence emission lifetime or delayed fluorescence lifetime of the first organic compound at 77K is 1.50 times or more the phosphorescence emission lifetime or delayed fluorescence lifetime of a third organic compound in which the deuterium of the first organic compound is hydrogen at 77K. The phosphorescence emission lifetime or delayed fluorescence lifetime of the second organic compound at 77K is 3.00 times or more the phosphorescence emission lifetime or delayed fluorescence lifetime of a fourth organic compound in which the deuterium of the second organic compound is hydrogen at 77K.

[0018] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the peak wavelength of the emission spectrum in the light emitted by the substance capable of converting triplet excitation energy into light emission is 500 nm or more and 600 nm or less.

[0019] Alternatively, another aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission. The first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium, and the phosphorescence emission lifetime or delayed fluorescence lifetime of the first organic compound at 77K is X times the phosphorescence emission lifetime or delayed fluorescence lifetime of a third organic compound at 77K where the deuterium of the first organic compound is hydrogen, and the phosphorescence emission lifetime or delayed fluorescence lifetime of the second organic compound at 77K is Y times the phosphorescence emission lifetime or delayed fluorescence lifetime of a fourth organic compound at 77K where the deuterium of the second organic compound is hydrogen. When the value obtained by multiplying X and Y is 1.26 or more, it is a light-emitting device.

[0020] Alternatively, another aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission. The peak wavelength of the light emitted by the substance capable of converting triplet excitation energy into light emission is 500 nm or more and 600 nm or less. The first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium, and the phosphorescence emission lifetime or delayed fluorescence lifetime of the first organic compound at 77K is X times the phosphorescence emission lifetime or delayed fluorescence lifetime of a third organic compound at 77K where the deuterium of the first organic compound is hydrogen, and the phosphorescence emission lifetime or delayed fluorescence lifetime of the second organic compound at 77K is Y times the phosphorescence emission lifetime or delayed fluorescence lifetime of a fourth organic compound at 77K where the deuterium of the second organic compound is hydrogen. When the value obtained by multiplying X and Y is 4.50 or more, it is a light-emitting device.

[0021] Alternatively, another aspect of the present invention is a light-emitting device having a first electrode, a second electrode, and a light-emitting layer, the light-emitting layer being located between the first electrode and the second electrode, the light-emitting layer having a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission, the first organic compound having a π-electron-deficient heteroaromatic ring, the second organic compound having a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound containing deuterium, and the difference between the 5% weight loss temperature of the first organic compound at 10 Pa and the 5% weight loss temperature of the second organic compound at 10 Pa being 60 °C or less.

[0022] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the substance capable of converting triplet excitation energy into light emission is a phosphorescent substance.

[0023] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the first organic compound and the second organic compound form an exciplex.

[0024] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the first organic compound is an organic compound having a diazine skeleton or a triazine skeleton, and the second organic compound is an organic compound having a bicarbazole skeleton.

[0025] Another aspect of the present invention is also a light-emitting device in the above configuration, wherein the substance capable of converting triplet excitation energy into light emission contains deuterium.

[0026] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the light-emitting device further has a first layer, the first layer is located between the light-emitting layer and the first electrode, the first layer contains a fifth organic compound, and the fifth organic compound has a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton and contains deuterium.

[0027] Alternatively, in another aspect of the present invention, in the above configuration, the light-emitting device further has a first layer, the first layer is located between the light-emitting layer and the first electrode, the first layer contains a fifth organic compound, the fifth organic compound has a π-electron-excessive heteroaromatic ring or an aromatic amine skeleton, the fifth organic compound contains deuterium, and the difference between the lowest triplet excitation level of the first organic compound and the lowest triplet excitation level of the fifth organic compound is 0.10 eV or less.

[0028] Alternatively, in another aspect of the present invention, in the above configuration, the fifth organic compound is the same organic compound as the second organic compound.

[0029] Alternatively, in another aspect of the present invention, there is a display device including the light-emitting device described in any of the above.

[0030] Alternatively, in another aspect of the present invention, there is an electronic device including the above light-emitting device, a sensor, an operation button, a speaker, or a microphone.

[0031] Alternatively, in another aspect of the present invention, there is a lighting device including the above light-emitting device and a housing.

[0032] Alternatively, in another aspect of the present invention, there is an organic compound represented by the following.

[0033] [Chemical formula] [Advantages of the Invention]

[0034] In one aspect of the present invention, a light-emitting device with high luminous efficiency can be provided. Alternatively, in one aspect of the present invention, a light-emitting device with good reliability can be provided. Alternatively, any one of a display device, an electronic device, and a lighting device with low power consumption can be provided. Alternatively, any one of a display device, an electronic device, and a lighting device with high reliability can be provided. Alternatively, in one aspect of the present invention, an organic compound with good reliability can be provided.

[0035] Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have to have all of these effects. Note that other effects will be obvious from the descriptions in the specification, drawings, claims, etc., and it is possible to extract these other effects from the descriptions in the specification, drawings, claims, etc.

Brief Description of the Drawings

[0036]

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Mode for Carrying Out the Invention

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that the form and details thereof can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below.

[0038] In this specification and the like, a device manufactured using a metal mask or an FMM (fine metal mask, high-definition metal mask) may be referred to as a device having an MM (metal mask) structure. Also, in this specification and the like, a device manufactured without using a metal mask or an FMM may be referred to as a device having an MML (metal maskless) structure.

[0039] (Embodiment 1) The organic semiconductor device has at least a pair of electrodes (a first electrode and a second electrode) and an organic compound layer, and the organic compound layer includes an active layer or an active region. The organic compound layer preferably has a laminated structure composed of functional layers each including an organic compound that is functionally separated as shown in FIG. 1 and has characteristics corresponding to its role.

[0040] The functions required for these functional layers are various, and typical functional layers include, for example, a carrier injection layer, a carrier transport layer, an active layer (such as a light-emitting layer, a photoelectric conversion layer), a charge generation layer, a carrier blocking layer, an exciton blocking layer, and the like. Note that each functional layer may also have other functions. For example, since it is assumed that an electron blocking layer transports holes and a hole blocking layer transports electrons, it can also be said to be a carrier transport layer (a hole transport layer or an electron transport layer).

[0041] Each functional layer is composed of an organic compound having characteristics corresponding to the functions required for each as described above. Therefore, the development of organic compounds having characteristics suitable for each functional layer has been actively promoted more than ever, and many organic compounds have been proposed and put into practical use.

[0042] In addition, the characteristics of the light-emitting device also vary greatly depending on how these organic compounds are combined and used. Research on such light-emitting device structures is also actively underway.

[0043] For example, first, in a current-excited light-emitting device, by using a substance (phosphorescent substance, substance showing thermally activated delayed fluorescence) that can convert triplet excitation energy into light as a light-emitting substance (guest material), it is possible to obtain a light-emitting device with high luminous efficiency.

[0044] In addition, a configuration is known in which two different organic compounds (specifically, an organic compound having electron-transporting properties and an organic compound having hole-transporting properties) are used as host materials for the light-emitting layer together with a light-emitting substance (guest material).

[0045] Among them, a configuration in which an exciplex formed by two different organic compounds in the light-emitting layer is used as an energy donor and a substance (phosphorescent substance, substance showing thermally activated delayed fluorescence) that can convert triplet excitation energy into light is used as an energy acceptor, so-called ExTET (Exciplex-Triplet Energy Transfer), is an excellent technology that can simultaneously achieve high efficiency, low driving voltage, and long life.

[0046] That is, a light-emitting device having a light-emitting layer provided with an exciplex as an energy donor and a substance that can convert triplet excitation energy into light as an energy acceptor, that is, a light-emitting substance, can be a light-emitting device having very good characteristics.

[0047] Here, when both of the two organic compounds (the first organic compound and the second organic compound) that function as host materials have deuterium, a more reliable light-emitting device can be obtained. In particular, as will be described later, the difference in the lowest triplet excitation level (T 1 level) between the first organic compound having deuterium and the T 1 level of the second organic compound is small, that is, the T 1 level of the first organic compound and the T 1 level of the second organic compound are close to each other. In this case, the triplet excitation energy is less likely to be biased towards either organic compound, and energy transfer from the triplet excited state of each compound to a substance that can convert the triplet excitation energy into light can occur. By improving the energy transfer efficiency from each of these compounds due to the influence of deuterium, it becomes possible to suppress the degradation of the first organic compound and the second organic compound having deuterium.

[0048] This is particularly effective when the two organic compounds form an exciplex. Regarding the singlet excitation energy of the exciplex, since the singlet excitation energy of the exciplex is lower than the singlet excitation energies of the first organic compound and the second organic compound, energy is transferred from the exciplex to the luminescent substance. However, regarding the triplet excitation energy of the exciplex, in addition to directly transferring energy to the luminescent substance, a path for indirectly transferring energy through the triplet excited states of the first organic compound and / or the second organic compound can also occur. In particular, as will be described later, the difference in the T 1 level between the first organic compound having deuterium and the T 1 level of the second organic compound is small, that is, the T 1 level of the first organic compound and the T 1When the levels are close, energy transfer to a substance capable of converting triplet excitation energy into light can occur via the triplet excited state of each compound. This is because the excitation energy is less likely to be biased towards either organic compound. By the energy transfer efficiency from the triplet excited state of each of these compounds being improved by the influence of deuterium, it becomes possible to suppress the degradation of the first organic compound and the second organic compound having deuterium.

[0049] Thereby, a light-emitting device using an exciplex formed of a deuterated organic compound as an energy donor is less degraded than a light-emitting device using an exciplex formed of a non-deuterated organic compound as an energy donor, and can be made into a light-emitting device with good reliability.

[0050] Note that the first organic compound and the second organic compound may each be an organic compound having both hydrogen and deuterium, or may be an organic compound having no hydrogen but having deuterium.

[0051] Also, the first organic compound and the second organic compound may be fully deuterated as a whole molecule, but it is preferable that the group or skeleton where the lowest triplet excitation level is localized is deuterated. Thereby, the first organic compound or the second organic compound can be obtained at a lower cost than fully deuterating the whole molecule.

[0052] In this specification, "having deuterium" means that the ratio of deuterium in the hydrogen and deuterium of the organic compound is much higher than the natural abundance ratio of deuterium, specifically 500 times or more, and "deuterated organic compound" means an organic compound in which the ratio of deuterium in the hydrogen and deuterium of the organic compound is much higher than the natural abundance ratio of deuterium, specifically 500 times or more. Also, this ratio is the average of a plurality of target organic compounds present in a certain area, not the ratio for one molecule.

[0053] The first organic compound is an organic compound having electron transporting properties, and preferably contains a π-electron deficient heteroaromatic ring. The second organic compound is an organic compound having hole transporting properties, and preferably contains a π-electron excessive heteroaromatic ring or an aromatic amine skeleton.

[0054] In the light-emitting device according to one embodiment of the present invention, the improvement in the energy transfer efficiency due to the first organic compound and the second organic compound having deuterium is attributed to the fact that the phosphorescence lifetime or delayed fluorescence lifetime of the deuterated organic compound is longer than the phosphorescence lifetime or delayed fluorescence lifetime of the non-deuterated organic compound. This is because the intramolecular vibration in the lowest triplet excited state (T 1 state) of the deuterated organic compound is more suppressed than the intramolecular vibration of the non-deuterated organic compound, and the non-radiative transition from the T 1 state to a more stable state is suppressed.

[0055] The energy transfer efficiency φ ET from the energy donor (excimer in one embodiment of the present invention) to the energy acceptor (substance capable of converting triplet excitation energy into light emission in one embodiment of the present invention) is represented by the following formula (1). From this formula, in order to increase the energy transfer efficiency φ ET , it can be seen that the rate constant k h*→g of energy transfer should be increased, and the other competing rate constants k r + k nr (= 1 / τ) should be relatively small.

[0056] In formula (1), k r represents the rate constant of the light emission process of the energy donor (fluorescence when discussing energy transfer from the singlet excited state, phosphorescence or delayed fluorescence when discussing energy transfer from the triplet excited state), k nr represents the rate constant of the non-light emission process (thermal deactivation and intersystem crossing) of the energy donor, and τ represents the measured lifetime of the excited state of the energy donor. Also, k h*→g represents the rate constant of energy transfer (Förster mechanism or Dexter mechanism).

[0057]

Number

[0058] Rate constant k of energy transfer h*→g In the case of an organic compound that is not deuterated and an organic compound that is deuterated, since the atomic arrangement, spectral shape, etc. of the molecule are almost unchanged, they are almost the same (see the following formula (2) or (3)). Therefore, in the comparison between an organic compound that is not deuterated and an organic compound that is deuterated, the rate constant k of energy transfer h*→g It can be seen that it is greatly affected by the emission lifetime (phosphorescence lifetime or delayed fluorescence lifetime) τ. That is, the energy transfer efficiency is improved by increasing the emission lifetime (phosphorescence lifetime or delayed fluorescence lifetime).

[0059]

Number

[0060]

Number

[0061] Formula (2) is the rate constant k of the Förster mechanism, and formula (3) is the rate constant k of the Dexter mechanism h*→g is the formula of.

[0062] In formula (2), ν represents the frequency, and f′ h (ν) represents the normalized emission spectrum of the host material (fluorescence spectrum when discussing energy transfer from the singlet excited state, phosphorescence spectrum when discussing energy transfer from the triplet excited state), and ε g(ν) represents the molar extinction coefficient of the guest material, N represents Avogadro's number, n represents the refractive index of the medium, R represents the intermolecular distance between the host material and the guest material, τ represents the measured lifetime of the excited state (fluorescence lifetime, phosphorescence lifetime), φ represents the luminescence quantum yield (fluorescence quantum yield when discussing energy transfer from the singlet excited state, phosphorescence quantum yield when discussing energy transfer from the triplet excited state), and K 2 is a coefficient (0 to 4) representing the orientation of the transition dipole moments of the host material and the guest material. In the case of random orientation, K 2 = 2 / 3.

[0063] In Equation (3), h is Planck's constant, K is a constant with the dimension of energy, ν represents the frequency, and f′ h (ν) represents the normalized emission spectrum of the host material (fluorescence spectrum when discussing energy transfer from the singlet excited state, phosphorescence spectrum when discussing energy transfer from the triplet excited state), and ε′ g (ν) represents the normalized absorption spectrum of the guest material, L represents the effective molecular radius, and R represents the intermolecular distance between the host material and the guest material.

[0064] As described above, in the energy transfer from the first organic compound and the second organic compound, since the energy transfer efficiency from each triplet excited state is important, the lifetime of the triplet excited state is important. That is, by increasing the phosphorescence lifetime or delayed fluorescence lifetime of the deuterated first organic compound and the second organic compound, the energy transfer efficiency can be improved, and the deterioration of the deuterated organic compound can be suppressed. Thereby, a light-emitting device having an energy donor using a deuterated organic compound can suppress the deterioration of the organic compound more than a light-emitting device having an energy donor using a non-deuterated organic compound, and can be a highly reliable light-emitting device.

[0065] Note that in the light-emitting device according to one aspect of the present invention, an exciplex formed from a first organic compound and a second organic compound serves as an energy donor. As described above, regarding the triplet excitation energy, there may be a path for energy transfer from the triplet excited state of the exciplex through the triplet excited states of the first organic compound and the second organic compound. Therefore, the phosphorescence lifetime or delayed fluorescence lifetime of the first organic compound and the second organic compound constituting the exciplex is important. Here, in the light-emitting device according to one aspect of the present invention, since each of the first organic compound and the second organic compound has deuterium, the phosphorescence lifetime or delayed fluorescence lifetime becomes longer than a certain level, and it has been found that the reliability of the light-emitting device using the exciplex as an energy donor is significantly improved. When comparing the lifetimes, it is preferable to make the measurement conditions the same. For example, it is preferable to perform the comparison with the same sample shape such as between thin films or between solutions. Also, for the phosphorescence lifetime, those measured at a low temperature (any temperature in the range from 4K to 80K) are compared, and for the delayed fluorescence lifetime, those measured at room temperature (any temperature in the range from 290K to 300K) are compared.

[0066] That is, the first organic compound is an organic compound whose phosphorescence lifetime or delayed fluorescence lifetime is 1.20 times or more the phosphorescence lifetime or delayed fluorescence lifetime of a third organic compound in which the deuterium of the first organic compound is hydrogen, and the second organic compound is preferably an organic compound whose phosphorescence lifetime or delayed fluorescence lifetime is 1.05 times or more the phosphorescence lifetime or delayed fluorescence lifetime of a fourth organic compound in which the deuterium of the second organic compound is hydrogen. At this time, it is preferable that the light emitted by a substance (light-emitting substance contained in the light-emitting layer) that can convert triplet excitation energy into light is light emission in the blue region, that is, its peak wavelength is typically 450 nm or more and less than 500 nm. Alternatively, it is preferable that the light emitted by a substance (light-emitting substance contained in the light-emitting layer) that can convert triplet excitation energy into light is light emission in the red region, that is, its peak wavelength is typically more than 600 nm and 700 nm or less.

[0067] Alternatively, the first organic compound is an organic compound whose phosphorescence lifetime or delayed fluorescence lifetime is 1.50 times or more the phosphorescence lifetime or delayed fluorescence lifetime of a third organic compound in which the deuterium of the first organic compound is hydrogen, and the second organic compound is preferably an organic compound whose phosphorescence lifetime or delayed fluorescence lifetime is 3.00 times or more the phosphorescence lifetime or delayed fluorescence lifetime of a fourth organic compound in which the deuterium of the second organic compound is hydrogen. At this time, it is preferable that the light emitted by a substance capable of converting triplet excitation energy into light (a light-emitting substance contained in the light-emitting layer) is light emission in the green region, that is, its peak wavelength is typically 500 nm or more and 600 nm or less.

[0068] Alternatively, in the light-emitting device of one aspect of the present invention, the numerical value obtained by multiplying the magnification factors by which the phosphorescence lifetime or delayed fluorescence lifetime is increased due to the first organic compound and the second organic compound each having deuterium is a certain value or more, and it has been found that the reliability of the light-emitting device using the exciplex as an energy donor is significantly improved.

[0069] That is, in the light-emitting device of one aspect of the present invention, when the phosphorescence lifetime of the first organic compound is X times the phosphorescence lifetime of a third organic compound in which the deuterium of the first organic compound is hydrogen, and the phosphorescence lifetime of the second organic compound is Y times the phosphorescence lifetime of a fourth organic compound in which the deuterium of the second organic compound is hydrogen, it is preferable to use the first organic compound and the second organic compound in which the numerical value obtained by multiplying X and Y is 1.26 or more.

[0070] In addition, when the phosphorescence lifetime or delayed fluorescence lifetime of the first organic compound is X times the phosphorescence lifetime or delayed fluorescence lifetime of a third organic compound in which the deuterium of the first organic compound is hydrogen, and the phosphorescence lifetime or delayed fluorescence lifetime of the second organic compound is Y times the phosphorescence lifetime or delayed fluorescence lifetime of a fourth organic compound in which the deuterium of the second organic compound is hydrogen, it is preferable to use the first organic compound and the second organic compound in which the numerical value obtained by multiplying X and Y is a certain value or more because a light-emitting device with better characteristics can be obtained.

[0071] Specifically, when the light emitted by a substance capable of converting triplet excitation energy into light emission (the light-emitting substance contained in the light-emitting layer) is light emission in the green region, that is, when its peak wavelength is typically 500 nm or more and 600 nm or less, it is preferable to use a first organic compound and a second organic compound in which the numerical value obtained by multiplying X and Y is 4.50 or more, because a light-emitting device with better characteristics can be obtained.

[0072] Alternatively, when the light emitted by a substance capable of converting triplet excitation energy into light emission (the light-emitting substance contained in the light-emitting layer) is light emission in the blue region, that is, when its peak wavelength is typically 450 nm or more and less than 500 nm, it is preferable to use a first organic compound and a second organic compound in which the numerical value obtained by multiplying X and Y is 1.26 or more. Alternatively, when the light emitted by a substance capable of converting triplet excitation energy into light emission (the light-emitting substance contained in the light-emitting layer) is light emission in the red region, that is, when its peak wavelength is typically more than 600 nm and 700 nm or less, it is preferable to use a first organic compound and a second organic compound in which the numerical value obtained by multiplying X and Y is 1.26 or more.

[0073] The phosphorescence lifetime and the delayed fluorescence lifetime are measured and calculated by performing time-resolved measurement by measuring the intensity of the light emission that decays at regular intervals after blocking the excitation light with a shutter. At this time, a fluorescence component may be mixed in the initial stage of the decay, and the shape of the graph may not be a straight line. In such a case, a starting point may be determined in the straight-line portion of the graph, and the time until the intensity at the starting point decays to 1 / e may be defined as the phosphorescence lifetime or the delayed fluorescence lifetime.

[0074] As shown in Fig. 2, the starting point was determined within the range where the graph is linear from the measurement data (left graph in Fig. 2), and t = 0 was set (here, the time when the light intensity reached 50% of the starting value of the measurement was set as t = 0) (right graph in Fig. 2). Then, the time until the light intensity decays to 1 / e of the value at t = 0 is defined as the phosphorescence lifetime or the delayed fluorescence lifetime. In Fig. 2, the graph was created with the time when the measurement data reached 50% of the starting intensity of the measurement as time 0 s. When the light intensity at 0 s was set to 1, the time when the light intensity becomes 1 / e is the phosphorescence lifetime or the delayed fluorescence lifetime. Note that although it is easy to use the intensity of 50% of the starting measurement intensity as the starting point, other values are also acceptable.

[0075] The measurement of the phosphorescence lifetime can be carried out, for example, using a fluorometer such as FP - 8600 manufactured by JASCO Corporation, with a liquid nitrogen cooling unit installed at liquid nitrogen temperature (77K). The solution of the material is prepared in a glove box. The sample is dissolved in deoxygenated 2 - MeTHF and stirred with a stirrer at room temperature for about 30 minutes (heating is also carried out for materials that are difficult to dissolve), and a solution with a concentration of about 1.2E -4 M can be adjusted and used.

[0076] The time - resolved measurement can be performed by irradiating the sample cell with excitation light for about 30 seconds, blocking the excitation light with a shutter, and then measuring the intensity of the emitted light that decays at 10 - ms intervals. The wavelength for performing the phosphorescence lifetime measurement is preferably the peak wavelength of the phosphorescence spectrum. When there are multiple peaks in the phosphorescence spectrum, it is preferable to select the wavelength with the higher peak intensity. Depending on the wavelength, the fluorescence spectrum may be mixed and accurate measurement may not be possible. In such cases, it is preferable to compare the emission spectrum measured at low temperature (e.g., 77K) (the emission spectrum including phosphorescence) with the emission spectrum measured at room temperature (the emission spectrum including only fluorescence without phosphorescence) and select a phosphorescence wavelength where the fluorescence overlaps as little as possible. Alternatively, among the peaks of the phosphorescence spectrum, the peak wavelength with the longest wavelength can be selected. In the case of a frozen solution, emission from states other than the lowest triplet excited state may also be observed. In this case, the peak wavelength with the longest wavelength can be selected.

[0077] The excitation wavelength may be appropriately selected within a wavelength range where the influence of the solvent does not appear. If the material can be sufficiently excited, it is preferable to measure at 330 nm because the influence of the solvent does not appear. Further, the bandwidths of the excitation light and the measurement light may be about 10 nm.

[0078] Since the emission ideally decays as a single exponential function, the starting point is determined in the linear part of the graph, and the time until the intensity at the starting point decays to 1 / e can be defined as the phosphorescence lifetime or the delayed fluorescence lifetime.

[0079] Note that the fluorescence lifetime, the phosphorescence lifetime, and the delayed fluorescence lifetime can be distinguished by the length of the lifetime when time-resolved measurement is performed. The emission lifetime with a lifetime of around n seconds is the fluorescence lifetime, and the emission lifetime with a lifetime of μ seconds to m seconds or more is the phosphorescence lifetime and the delayed fluorescence lifetime.

[0080] Alternatively, in the light-emitting device according to one aspect of the present invention, the reliability is improved in relation to the extension of the phosphorescence lifetime of the first organic compound and the second organic compound, that is, the lifetime of the triplet excitons. The extension of the lifetime of the triplet excitons is due to the suppression of the non-radiative deactivation of the triplet excitation energy caused by the suppression of vibration by deuteration. At this time, the difference between the T 1 level of the first organic compound and the T 1 level of the second organic compound is small, so that the excitation energy is less likely to be biased to either organic compound, and it is possible to prevent either one from being significantly deteriorated, which is preferable because the reliability of the light-emitting device is improved. Specifically, the difference between the T 1 level of the first organic compound and the T 1 level of the second organic compound is preferably 0.20 eV or less, more preferably 0.15 eV or less, and even more preferably 0.10 eV or less.

[0081] Note that T 1The level can be calculated by measuring the emission spectrum (phosphorescence spectrum) at a measurement temperature of 10 K using a thin film obtained by forming a sample, for example, 50 nm thick on a quartz substrate. For the measurement, a microscopic PL device LabRAM HR-PL (manufactured by Horiba, Ltd.) can be used, and a He-Cd laser (325 nm) can be used as the excitation light. The emission end can be calculated by drawing a tangent at the value where the slope on the short-wavelength side of the peak (or shoulder peak) observed at the shortest wavelength of the emission spectrum (phosphorescence spectrum) is maximized, and then calculating from the intersection of the tangent and the horizontal axis (wavelength) or the baseline.

[0082] Alternatively, in one aspect of the present invention, it is preferable that the sublimation temperature of the first organic compound and the sublimation temperature of the second organic compound are close to each other. For example, the difference between the 5% weight loss temperature measured by thermogravimetric measurement of the first organic compound and the 5% weight loss temperature measured by thermogravimetric measurement of the second organic compound is preferably 60°C or less. More preferably, it is 45°C or less, still more preferably 20°C or less, and even more preferably 10°C or less. Thereby, since vapor deposition can be performed using a material in which the first organic compound and the second organic compound are mixed, the number of vapor deposition sources can be reduced, and it becomes possible to provide an inexpensive light-emitting device with good characteristics. The 5% weight loss temperature may be a value at atmospheric pressure, but it is preferably a value obtained under conditions close to the pressure during vapor deposition, for example, a value at about 10 Pa.

[0083] The 5% weight loss temperature can be determined from the relationship between weight and temperature (thermogravimetric measurement) by performing thermogravimetric measurement-differential thermal analysis (TG-DTA: Thermogravimetry-Differential Thermal Analysis). When the pressure for vapor deposition is determined in advance, it is preferable to use the value measured under that pressure.

[0084] Note that T in the first organic compound and the second organic compound 1The difference in levels, the difference in sublimation temperature, the elongation rate due to deuteration of the phosphorescence lifetime or delayed fluorescence lifetime, and their product can be combined to realize a light-emitting device having better characteristics.

[0085] Further, it is preferable that the photoluminescence (PL) spectrum of the exciplex formed from the first organic compound and the second organic compound and the PL spectrum of the light-emitting substance (a substance capable of converting triplet excitation energy into light) have an overlap. This is because the excitation energy of the exciplex, which is an energy donor, and the excitation energy of the light-emitting substance are close, so that the driving voltage of the light-emitting device can be reduced. Therefore, the difference in the maximum peak wavelength between the PL spectrum of the exciplex and the PL spectrum of the light-emitting substance is preferably 30 nm or less. Alternatively, a light-emitting device having a configuration in which the difference between the wavelength of the emission end on the short-wavelength side in the PL spectrum of the exciplex and the wavelength of the emission end on the short-wavelength side in the PL spectrum of the light-emitting substance is 30 nm or less is preferable because the driving voltage can be reduced.

[0086] The PL spectrum of the exciplex is preferably measured using a co-evaporated film of the first organic compound and the second organic compound. The sample form when measuring the PL spectrum of the light-emitting substance (a substance capable of converting triplet excitation energy into light) may be a thin film or a solution, but a solution is preferable from the viewpoint of verifying the state of isolated molecules. The solvent of the solution is not particularly limited as long as the same solvent is used for comparison, but a solvent having relatively low polarity, such as toluene or chloroform, is preferable.

[0087] When the light emitted by a substance capable of converting triplet excitation energy into light emission (the light-emitting substance contained in the light-emitting layer) is light emission in the blue region, that is, when its peak wavelength is typically 450 nm or more and less than 500 nm, as the first organic compound, an organic compound having a triazine skeleton or a diazine skeleton is preferable, and as the second organic compound, an organic compound having a carbazole skeleton is preferable. Specifically, as the first organic compound, 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole-1,2,3,4,5,6,7,8,1’,2’,3’,4’,5’,6’,7’,8’-d 16 )(abbreviation: SiTrzCz2-d16), as the second organic compound, 9-[3-(triphenylsilyl)phenyl]-3,9’-(bi-9H-carbazole-d15) (abbreviation: PSiCzCz-d15), 9’-[3-(triphenylsilyl)phenyl]-9’H-9,3’:6’,9’’-tercarbazole-1,1’,1’’,2,2’,2’’,3,3’’,4,4’,4’’,5,5’,5’’,6,6’’,7,7’,7’’,8,8’,8’’-d22 (abbreviation: PSiCzGI-d22), etc. can be mentioned.

[0088] Also, when the light emitted by a substance capable of converting triplet excitation energy into light (a light-emitting substance contained in the light-emitting layer) is light emission in the green region, that is, when its peak wavelength is typically 500 nm or more and 600 nm or less, as the first organic compound, an organic compound having a diazine skeleton or a triazine skeleton is preferable, and as the second organic compound, an organic compound having a carbazole skeleton is preferable. Specifically, as the first organic compound, 8-(1,1’:4’,1’’-terphenyl-3-yl-2,4,5,6,2’,3’,5’,6’,2’’,3’’,4’’,5’’,6’’-d13)-4-[3-(dibenzothiophen-4-yl-1,2,3,6,7,8,9-d7)phenyl-2,4,6-d3]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d23), 8-(1,1’:4’,1’’-terphenyl-3-yl-2,4,5,6,2’,3’,5’,6’,2’’,3’’,4’’,5’’,6’’-d13)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d13), 11-[4-(biphenyl-4-yl-2,2′,3,3′,4′,5,5′,6,6′-d9)-6-(phenyl-2,3,4,5,6-d5)-1,3,5-triazin-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole-1,2,3,4,5,6,7,8,9,10-d10, and as the second organic compound, 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9’-(phenyl-2,3,4,5,6-d5)-3,3’-bi-9H-carbazole-1,1’,2,2’,4,4’,5,5’,6,6’,7,7’,8,8’-d14 (abbreviation: βNCCP-d26), 9-phenyl-9’-(phenyl-2,3,4,5,6-d5)-3,3’-bis(9H-carbazole) (abbreviation: PCCP-d5), etc. can be mentioned.

[0089] This embodiment can be used in any combination with other embodiments.

[0090] (Embodiment 2) In this embodiment, a light-emitting device, which is an organic semiconductor device according to one aspect of the present invention, will be described in detail. FIG. 1(A) shows a diagram representing a light-emitting device according to one aspect of the present invention. The light-emitting device according to one aspect of the present invention has an organic compound layer 103 between a first electrode 101 formed on an insulating layer 1000 and a second electrode 102 facing the first electrode 101. The organic compound layer 103 has at least a light-emitting layer 113 and may further include other functional layers. In FIGS. 1(A) and (B), as an example, an example including a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115 is shown, but it may have an exciton blocking layer, a charge generation layer, or the like. Note that, among the hole transport layer 112, the layer in contact with the light-emitting layer 113 may be particularly referred to as an electron blocking layer, and among the electron transport layer 114, the layer in contact with the light-emitting layer 113 may be particularly referred to as a hole blocking layer. In this embodiment, a case where the first electrode 101 functions as an anode and the second electrode 102 functions as a cathode will be described as an example, but the reverse is also possible.

[0091] Note that the light-emitting layer has the configuration described in Embodiment 1. Thus, the light-emitting device according to one aspect of the present invention can be a highly reliable light-emitting device.

[0092] The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof having a large work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO: Indium Tin Oxide), indium tin silicon oxide (ITSO: Indium Tin Silicon Oxide) containing silicon or silicon oxide, indium zinc oxide, indium tungsten zinc oxide (IWZO) containing tungsten oxide and zinc oxide, etc. can be mentioned. These conductive metal oxide films are usually formed by sputtering, but may also be produced by applying a sol-gel method or the like. As an example of the production method, indium zinc oxide can be formed by sputtering using a target obtained by adding 1 to 20 wt% of zinc oxide to indium oxide. Also, indium tungsten zinc oxide (IWZO) containing tungsten oxide and zinc oxide can also be formed by sputtering using a target containing 0.5 to 5 wt% of tungsten oxide and 0.1 to 1 wt% of zinc oxide with respect to indium oxide. In addition, materials used for the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), aluminum (Al), or nitrides of metal materials (for example, titanium nitride), etc. Also, a layer formed by laminating these may be used as the anode. For example, a film laminated in the order of Al, Ti, and ITSO on Ti is preferable because it has good reflectivity, is highly efficient, and enables high definition of several thousand ppi. Alternatively, graphene can also be used as the material for the anode. Note that by using a composite material capable of forming the hole injection layer 111 described later as a layer (typically the hole injection layer) in contact with the anode, the electrode material can be selected regardless of the work function.

[0093] The hole injection layer 111 is provided in contact with the anode and has a function of facilitating the injection of holes into the organic compound layer 103. The hole injection layer 111 is phthalocyanine (abbreviation: H 2It can be formed by phthalocyanine-based compounds or complex compounds such as phthalocyanine (abbreviation: Pc), copper phthalocyanine (abbreviation: CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviation: PEDOT / PSS).

[0094] Further, the hole injection layer 111 may be formed of a substance having electron acceptor properties. As the substance having acceptor properties, an organic compound having an electron-withdrawing group (such as a halogen group or a cyano group) can be used, and examples include 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-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene) malononitrile, and the like. In particular, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is thermally stable and preferable. Further, a [3]radialene derivative having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) is preferable because of its very high electron accepting property. Specifically, α,α’,α’’-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be mentioned. As the substance having acceptor properties, in addition to the organic compounds described above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used. In addition, phthalocyanine (abbreviation: H 2A hole injection layer 111 can also be formed of a phthalocyanine compound or complex compound such as phthalocyanine (abbreviation: Pc), copper phthalocyanine (abbreviation: CuPc), an aromatic amine compound such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid (abbreviation: PEDOT / PSS). A substance having an acceptor property can extract electrons from an adjacent hole transport layer (or hole transport material) by applying an electric field.

[0095] Further, the hole injection layer 111 is preferably formed of a composite material containing the above acceptor material and a hole transporting substance.

[0096] As the hole transporting substance used in the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. The hole transporting substance used in the composite material is preferably a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more. The hole transporting substance used in the composite material is preferably a compound having a condensed aromatic hydrocarbon ring or a π-electron excess type heteroaromatic ring. As the condensed aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. Further, as the π-electron excess type heteroaromatic ring, a condensed aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton in the ring is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed thereto is preferable.

[0097] Such a substance having hole transporting properties more preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it may be an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. Note that when such a substance having hole transporting properties is a substance having an N,N-bis(4-biphenyl)amino group, it is preferable because a light emitting device with good lifetime can be fabricated.

[0098] Examples of substances having hole-transporting properties as described above include, specifically, N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[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-biphenyl)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-(dibenzothiophene-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 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), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(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-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-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), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',Examples include 9’’-tercarbazole (abbreviation: PSiCzGI), etc.

[0099] In addition, as substances having hole-transporting properties, as other aromatic amine compounds, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0100] By forming the hole injection layer 111, the injectability of holes becomes good, and a light-emitting device with a small driving voltage can be obtained.

[0101] Among substances having acceptor properties, organic compounds having acceptor properties are easy to vaporize and easy to form films, so they are easy-to-use materials.

[0102] The hole transport layer 112 is formed by including a substance having hole-transporting properties. As the substance having hole-transporting properties, it preferably has a hole mobility of 1×10 -6 cm 2 / Vs or more.

[0103] Examples of the substance having hole transporting property include compounds having an aromatic amine skeleton such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-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-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-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)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-Bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) and other compounds having a carbazole skeleton, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), etc., and compounds having a furan skeleton such as 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), etc. Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Also, the organic compounds listed as hole-transporting substances used in the composite material of the hole injection layer 111 can also be suitably used as materials constituting the hole transport layer 112.,

[0104] The hole transport layer 112 may have a laminated structure. Among them, in the layer in contact with the light-emitting layer 113 (electron blocking layer), it is preferable to use a deuterated organic compound. Examples of materials preferably used for the electron blocking layer include the same materials as the second organic compound described later. By using a deuterated material for the electron blocking layer, even when the electron blocking layer in contact with the light-emitting layer is excited, deterioration of the organic compound used for the electron blocking layer can be suppressed, deterioration of the light-emitting device can be suppressed, and a highly reliable light-emitting device can be obtained.,

[0105] The light-emitting center substance contained in the light-emitting layer 113 is preferably a phosphorescent substance or a substance showing thermally activated delayed fluorescence (TADF).

[0106] When a phosphorescent substance is used as the light-emitting substance in the light-emitting layer 113, examples of the phosphorescent substance include the following materials.

[0107] 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 )、such as organometallic iridium complexes having a 4H-triazole skeleton, tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) 3 )、tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me) 3 )、such as organometallic iridium complexes having a 1H-triazole skeleton, fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim) 3 )、tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) 3 )、tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN3}-4-cyanophenyl-κC)iridium(III) (abbreviation: CNImIr), such as organometallic iridium complexes having an imidazole skeleton, tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb) 3 )、such as organometallic complexes having a benzimidazolidene skeleton, bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4’,6’-difluorophenyl)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(CF 3 ppy) 2 (pic)]), bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium(III) acetylacetonate (abbreviation: FIracac) and other organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI) and other platinum complexes. These are compounds that exhibit blue phosphorescent emission and have an emission peak in the wavelength range from 450 nm to 520 nm. Also, compounds in which a part of the hydrogen atoms of these compounds is deuterium can also be used.

[0108] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) 3 )), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) 3 ), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) 2 (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) 2 (acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) 2(acac)), bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato](acetylacetonato)iridium(III) (abbreviation: [Ir(mpmppm) 2 (acac)), bis(4,6-diphenylpyrimidinato)(acetylacetonato)iridium(III) (abbreviation: [Ir(dppm) 2 (acac)), organometallic iridium complexes having a pyrimidine skeleton such as bis(3,5-dimethyl-2-phenylpyrazinato)(acetylacetonato)iridium(III) (abbreviation: [Ir(mppr-Me) 2 (acac)), bis(5-isopropyl-3-methyl-2-phenylpyrazinato)(acetylacetonato)iridium(III) (abbreviation: [Ir(mppr-iPr) 2 (acac)), organometallic iridium complexes having a pyrazine skeleton such as tris(2-phenylpyridinato-N,C 2’ )iridium(III) (abbreviation: [Ir(ppy) 3 ), bis(2-phenylpyridinato-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(ppy) 2 (acac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) 2 (acac)), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) 3 ), tris(2-phenylquinolinato-N,C 2’ )iridium(III) (abbreviation: [Ir(pq) 3 ), bis(2-phenylquinolinato-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(pq) 2 (acac)), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d 3 -methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d 3 ) 2 (mbfpypy-d 3))、{2-(methyl-d 3 )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d 3 )-2-[5-(methyl-d 3 )-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6) 2 (mbfpypy-iPr-d 4 ))、[2-d 3 -methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) 2 (mbfpypy-d 3 ))、[2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) 2 (mdppy))、[2-(4-d 3 -methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d 3 -methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d 3 )2(mdppy-d 3 )])、[2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) 2 (mbfpypy)])、[2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy) 2 (mdppy)])、tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d 3 ) 3In addition to the organometallic iridium complex having a pyridine skeleton as described above, rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) 3 (Phen)]) can be mentioned. These are mainly compounds that exhibit green phosphorescent emission and have an emission peak in the wavelength range from 500 nm to 600 nm. In addition, the organometallic iridium complex having a pyrimidine skeleton is particularly preferable because it is also remarkably excellent in reliability or luminous efficiency. Further, a compound in which a part of the hydrogen atoms of these compounds is deuterium can also be used.

[0109] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]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(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm) 2 (dpm)]) and other organometallic iridium complexes having a pyrimidine skeleton, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr) 2 (acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr) 2 (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) 2 (acac)]) and other organometallic iridium complexes having a pyrazine skeleton, tris(1-phenylisoquinolinato-N,C 2’ )iridium(III) (abbreviation: [Ir(piq) 3 ), bis(1-phenylisoquinolinato-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(piq)2 (acac)), (3,7 - diethyl - 4,6 - nonanedionato - κO4,κO6)bis[2,4 - dimethyl - 6 - [7 - (1 - methylethyl)-1 - isoquinolinyl - κN]phenyl - κC]iridium(III), (3,7 - diethyl - 4,6 - nonanedionato - κO4,κO6)bis[2,4 - dimethyl - 6 - [5 - (1 - methylethyl)-2 - quinolinyl - κN]phenyl - κC]iridium(III), in addition to organometallic iridium complexes having a pyridine skeleton, platinum complexes such as platinum(II) 2,3,7,8,12,13,17,18 - octaethyl - 21H,23H - porphyrin (abbreviation: PtOEP), tris(1,3 - diphenyl - 1,3 - propanedionato)(monophenanthroline)europium(III) (abbreviation: 3 (Phen)), tris[1 - (2 - thenoyl)-3,3,3 - trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: 3 (Phen)) and other rare earth metal complexes. These are compounds that exhibit red phosphorescent emission and have an emission peak in the wavelength range from 600 nm to 700 nm. In addition, organometallic iridium complexes having a pyrazine skeleton can obtain red emission with good chromaticity. Also, compounds in which part of the hydrogen in these compounds is deuterium can also be used.

[0110] In one aspect of the present invention, by using a deuterated compound as the light - emitting center substance, the luminous efficiency is improved. Therefore, the light - emitting center substance is preferably a deuterated material.

[0111] In addition to the phosphorescent compounds described above, known phosphorescent compounds may be selected and used.

[0112] As the TADF material, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc. can be used. Further, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd), etc. can be mentioned. Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (SnF 2 (Proto IX)), mesoporphyrin-tin fluoride complex (SnF 2 (Meso IX)), hematoporphyrin-tin fluoride complex (SnF 2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF 2 (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF 2 (OEP)), etioporphyrin-tin fluoride complex (SnF 2 (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl 2 OEP), etc.

[0113] [Chemical formula]

[0114] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9’-phenyl-9H,9’H-3,3’-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: 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-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10’H-spiro[acridine-9,9’-anthracene]-10’-one (abbreviation: ACRSA), and other heterocyclic compounds having one or both of a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used. Since the heterocyclic compound has a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring, it has both high electron transport properties and hole transport properties, which is preferable. Among them, among the skeletons having a π-electron-deficient heteroaromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are preferable because they are stable and have good reliability. In particular, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because they have high acceptor properties and good reliability. Also, among the skeletons having a π-electron-excessive heteroaromatic ring, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton are stable and have good reliability, so it is preferable to have at least one of these skeletons.Note that as the furan skeleton, a dibenzofuran skeleton is preferable, and as the thiophene skeleton, a dibenzothiophene skeleton is preferable. Further, as the pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, and a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable. Note that a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded has both the electron-donating property of the π-electron-rich heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring enhanced, and the energy difference between the lowest singlet excitation level (S 1 level) and the T 1 level becomes small, so that thermally activated delayed fluorescence can be efficiently obtained, which is particularly preferable. Note that instead of the π-electron-deficient heteroaromatic ring, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used. Further, as the π-electron-rich skeleton, an aromatic amine skeleton, a phenazine skeleton, or the like can be used. Further, as the π-electron-deficient skeleton, a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or borantrene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, or the like can be used. Thus, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used instead of at least one of the π-electron-deficient heteroaromatic ring and the π-electron-rich heteroaromatic ring. Further, a compound in which a part of the hydrogen atoms of these compounds is deuterium can also be used.

[0115]

Chemical formula

[0116] Note that the TADF material is an S 1 level and a T 1It is a material having a function of converting energy from triplet excitation energy to singlet excitation energy with a small difference from the level and by reverse intersystem crossing. Therefore, upconversion (reverse intersystem crossing) from triplet excitation energy to singlet excitation energy is possible with a small amount of thermal energy, and a singlet excited state can be efficiently generated. In addition, triplet excitation energy can be converted into light emission.

[0117] In addition, an exciplex (also referred to as an exciplex, exiplex or Exciplex) that forms an excited state with two types of substances has an S 1 level and a T 1 level, and has a function as a TADF material with an extremely small difference between the levels and capable of converting triplet excitation energy into singlet excitation energy.

[0118] Note that as an index of the T 1 level, a phosphorescence spectrum observed at a low temperature (for example, from 77 K to 10 K) may be used. As a TADF material, a tangent is drawn at the trailing edge on the short wavelength side of its fluorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the S 1 level, and a tangent is drawn at the trailing edge on the short wavelength side of the phosphorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the T 1 level. When the difference between the S 1 and T 1 is 0.3 eV or less, preferably 0.2 eV or less.

[0119] In addition, when using a TADF material as a light-emitting substance, the S 1 level of the energy donor is preferably higher than the S 1 level of the TADF material. Also, the T 1 level of the energy donor is preferably higher than the T 1 level of the TADF material.

[0120] As an organic compound that can be used as the first organic compound in the light-emitting layer 113, it has deuterium, and the electron mobility at the square root of the electric field strength [V / cm] of 600 is 1×10 -7 cm2 Preferably, it is 1×10 or more / Vs -6 cm 2 A substance having an electron-transporting property having an electron mobility of 1×10 or more / Vs is preferable.

[0121] As the first organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferable. Examples of the organic compound having a π-electron-deficient heteroaromatic ring skeleton include an organic compound containing a heteroaromatic ring having an azole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton.

[0122] Among them, an organic compound containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton is preferable because of its good reliability. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton or an organic compound containing a heteroaromatic ring having a triazine skeleton has high electron-transporting properties and contributes to a reduction in driving voltage. In addition, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because of their high acceptor properties and good reliability.

[0123] As the organic compound having a π-electron deficient heteroaromatic ring skeleton that can be used as the first organic compound, for example, a deuterated organic compound of the following organic compounds is preferred. 2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-Biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-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: TPBI), 2-[3-(Dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4’-Bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) and other organic compounds having an azole skeleton, 3,5-Bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-Tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-Di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2’-(1,3-Phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-Triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-Phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-Phenanthrenyl)-1-naphthalenyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-Triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen) and other organic compounds containing a heteroaromatic ring having a pyridine skeleton, 2-[3-(Dibenzothiophen-4-yl)phenyl]dibenzof,h]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3’-(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzof[h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3’-(9H-Carbazol-9-yl)biphenyl-3-yl]dibenzof[h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4’-(9-Phenyl-9H-carbazol-3-yl)-3,1’-biphenyl-1-yl]dibenzof[h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-Diphenyl-9H-carbazol-9-yl)phenyl]dibenzof[h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(Dibenzothiophen-4-yl)phenyl]dibenzof[h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzof[h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3’-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1’,2’:4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3’-(Dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1’,2’:4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-Bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9’-[Pyrimidine-4,6-diylbis(biphenyl-3,3’-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(Biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-Bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-Bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3’-(dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1’,2’:4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2’-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2’-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2’-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm) and other organic compounds having a diazine skeleton, 2-(biphenyl-4-yl)-4-phenyl-6-(9,9’-spirobi[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-Triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-Phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-Diphenyl-1,3,5-triazin-2-yl)phenyl]-9’-phenyl-2,3’-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3’-(9,9-Dimethyl-9H-fluorene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-Diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-inden[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(Dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-Tris[3’-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-Dimethyl-3-pyridinyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 2-[3’-(Triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-Diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[4-(2-Naphthalenyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9’-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)Tzn), 9,9’-{6-[3-(Triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-Phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 11-[4-(Biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-Dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)Tzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9’-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3’’-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1’:4’,1’’-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), and other organic compounds containing a heteroaromatic ring having a triazine skeleton are mentioned. Further, an organic compound containing a heteroaromatic ring having a diazine skeleton or an organic compound containing a heteroaromatic ring having a pyridine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferable because of their good reliability. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transporting properties and also contribute to reducing the driving voltage.,

[0124] As a substance having hole-transporting properties that can be used as the second organic compound of the light-emitting layer 113, an organic compound having deuterium and having an amine skeleton or a π-electron-excessive heteroaromatic ring skeleton is preferable. As the π-electron-excessive heteroaromatic ring, a condensed aromatic ring containing at least any one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton in the ring is preferable. Specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed thereto is preferable.

[0125] As such a substance having hole-transporting properties, it is more preferable to have any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group may be used. In addition, when these substances having hole-transporting properties are organic compounds having an N,N-bis(4-biphenyl)amino group, it is preferable because a light-emitting device having good lifetime can be fabricated.

[0126] As such organic compounds, for example, deuterated organic compounds of the following organic compounds are preferred. 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-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-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF) and other compounds having an aromatic amine skeleton, 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-Bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,Compounds having a carbazole skeleton such as 9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',9''-tercarbazole (abbreviation: PSiCzGI), compounds having a thiophene skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton such as 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 those described above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage.,

[0127] In the light-emitting device according to one embodiment of the present invention, at least one light-emitting layer has the configuration disclosed in Embodiment 1. When the light-emitting device has a plurality of light-emitting layers, a fluorescent light-emitting substance may be used as the light-emitting center substance in other light-emitting layers.

[0128] When using a fluorescent light-emitting substance as the light-emitting center substance, examples of materials that can be used include the following. In addition, other fluorescent light-emitting substances can also be used.

[0129] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyl-di-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-carbazole-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]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-Diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N’,N’-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N’,N’-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N’-diphenylquinacridone (abbreviation: DPQd), Rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 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]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: 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[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-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: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyrenediyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), and the like. In particular, condensed aromatic diamine compounds typified by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferable because they have high hole trap properties and are excellent in luminous efficiency or reliability.,

[0130] When a fluorescent luminescent substance is used as a luminescence center substance, as the host material, a material having an acene skeleton, particularly an anthracene skeleton, is suitable. When a substance having an anthracene skeleton is used as the host material of the fluorescent luminescent substance, it is possible to realize a luminescent layer with both good luminous efficiency and durability. As the substance having an anthracene skeleton used as the host material, a substance having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferable because it is chemically stable. Further, when the host material has a carbazole skeleton, it is preferable because the hole injection / transport property is enhanced. However, when it contains a benzocarbazole skeleton in which a benzene ring is further condensed with carbazole, the HOMO level is about 0.1 eV higher than that in the case of containing a carbazole skeleton, and holes can easily enter, so it is more preferable. In particular, when the host material contains a dibenzocarbazole skeleton, the HOMO level is about 0.1 eV higher than that in the case of containing a carbazole skeleton, holes can easily enter, the hole transport property is excellent, and the heat resistance is also high, so it is suitable. Therefore, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton) is more preferable as the host material. From the above viewpoint of hole injection / transport property, instead of the carbazole skeleton, a benzofluorene skeleton or a dibenzofluorene skeleton may be used.

[0131] Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenz[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), and the like. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA show very good characteristics, so they are preferred choices.

[0132] Note that by mixing the first organic compound and the second organic compound, the transport property of the light-emitting layer 113 can be easily adjusted, and the control of the recombination region can also be simply performed. The weight ratio of the contents of the first organic compound and the second organic compound may be such that the second organic compound : the first organic compound = 1:19 to 19:1.

[0133] In addition, the first organic compound and the second organic compound form an exciplex. By selecting a combination that forms an exciplex exhibiting emission that overlaps with the absorption band on the lowest energy side of the luminescent substance, energy transfer becomes smooth and efficient emission can be obtained, which is preferable. Further, by using such a configuration, the driving voltage is also reduced, which is preferable.

[0134] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the second organic compound is equal to or higher than the HOMO level of the first organic compound. Also, it is preferable that the LUMO level of the second organic compound is equal to or higher than the LUMO level of the first organic compound. Note that the LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0135] Note that the formation of the exciplex can be confirmed, for example, by comparing the emission spectrum of the second organic compound, the emission spectrum of the first organic compound, and the emission spectrum of a mixed film in which these materials are mixed, and observing the phenomenon that the emission spectrum of the mixed film is shifted to a longer wavelength (or has a new peak on the longer wavelength side) than the emission spectra of the respective materials. Alternatively, by comparing the transient photoluminescence (PL) of the second organic compound, the transient PL of the first organic compound, and the transient PL of a mixed film in which these materials are mixed, and observing differences in transient responses such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger proportion of the delayed component than the transient PL lifetimes of the respective materials, it can be confirmed. Also, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, by comparing the transient EL of the second organic compound, the transient EL of the first organic compound, and the transient EL of the mixed film thereof, and observing the difference in transient response, the formation of the exciplex can also be confirmed.

[0136] The electron transport layer 114 is a layer containing a substance having electron transporting properties. As the substance having electron transporting properties, the electron mobility at the square root of the electric field strength [V / cm] of 600 is 1×10-7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 A substance having an electron mobility of / Vs or more is preferable. In addition, as long as the substance has higher electron transportability than holes, other substances can be used. As the organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferable. Examples of the organic compound having a π-electron-deficient heteroaromatic ring include an organic compound containing a heteroaromatic ring having an azole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton, and it is preferable that any one or a plurality of them are used.

[0137] As the substance having electron transportability that can be used for the electron transport layer 114, the organic compounds listed as the organic compounds that can be used as the first organic compound by deuteration in the light-emitting layer 113 can be used in the same manner. Note that the substance having electron transportability that can be used for the electron transport layer 114 does not have to be deuterated.

[0138] Among the organic compounds listed as the organic compounds that can be used as the first organic compound by deuteration, an organic compound containing a heteroaromatic ring having a diazine skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton has good reliability and is preferable. In particular, organic compounds having a phenanthroline skeleton such as mTpPPhen, PnNPhen, and mPPhen2P are preferable, and organic compounds having a phenanthroline dimer structure such as mPPhen2P are more preferable because of their excellent stability.

[0139] Note that the electron transport layer 114 may have a stacked structure. Further, the layer in the electron transport layer 114 having a stacked structure that is in contact with the light-emitting layer 113 may function as a hole-blocking layer. When the electron transport layer in contact with the light-emitting layer functions as a hole-blocking layer, it is preferable to use a material whose HOMO level is 0.5 eV or more lower than the HOMO level of the material contained in the light-emitting layer 113.

[0140] As the electron injection layer 115, a layer containing an alkali metal or an alkaline earth metal, a compound or complex of an alkali metal or an alkaline earth metal, or 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py) etc. may be provided. The electron injection layer 115 may be one in which these are contained in a layer made of a substance having electron-transporting properties.

[0141] Further, a charge generation layer 116 may be provided instead of the electron injection layer 115 (Fig. 1(B)). The charge generation layer 116 is a layer capable of injecting holes into the layer in contact with the cathode side and electrons into the layer in contact with the anode side by applying a potential. The charge generation layer 116 contains at least a P-type layer 117. The P-type layer 117 is preferably formed using the composite material listed as a material capable of constituting the above-mentioned hole injection layer 111. Further, the P-type layer 117 may be formed by laminating a film containing an acceptor material and a film containing a hole-transporting material as materials constituting the composite material. By applying a potential to the P-type layer 117, electrons are injected into the electron transport layer 114 and holes are injected into the cathode, and the light-emitting device operates. Further, since the organic compound of one aspect of the present invention is an organic compound having a low refractive index, by using it for the P-type layer 117, a light-emitting device with good external quantum efficiency can be obtained.

[0142] Note that it is preferable that the charge generation layer 116 is provided with either or both of an electron relay layer 118 and an electron injection buffer layer 119 in addition to the P-type layer 117.

[0143] The electron relay layer 118 contains at least a substance having electron transporting properties, and has a function of preventing the interaction between the electron injection buffer layer 119 and the P-type layer 117 and smoothly transferring electrons. The LUMO level of the substance having electron transporting properties contained in the electron relay layer 118 is preferably positioned between the LUMO level of the acceptor substance in the P-type layer 117 and the LUMO level of the substance contained in the layer in contact with the charge generation layer 116 in the electron transport layer 114. When the specific energy level of the LUMO level in the substance having electron transporting properties used for the electron relay layer 118 is -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower, more preferably -4.30 eV or higher and -3.00 eV or lower, and even more preferably -4.30 eV or higher and -3.30 eV or lower, it is preferable because an increase in the driving voltage can be suppressed. Note that as the substance having electron transporting properties used for the electron relay layer 118, it is preferable to use a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0144] Specific examples of the substance having electron transporting properties used for the electron relay layer 118 include perylene tetracarboxylic acid derivatives such as diquinoxalino[2,3-a:2’,3’-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2’,3’-c]phenazine (abbreviation: HATNA-F6), 3,4,9,10-perylenetetracarboxylic diimide (abbreviation: PTCDI), 3,4,9,10-perylenetetracarboxyl-bis-benzimidazole (abbreviation: PTCBI), (C60-Ih)[5,6]fullerene (abbreviation: C60), (C70-D5h)[5,6]fullerene (abbreviation: C70). Further, a compound having a heterophane skeleton which is a cyclophane skeleton containing a heterocycle can be used. Examples of the compound include phthalocyanine (abbreviation: H 2Phthalocyanine compounds such as Pc) can be used. Also, metal phthalocyanines having copper, zinc, cobalt, iron, chromium, nickel, etc., and their derivatives, such as copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc), cobalt phthalocyanine (abbreviation: CoPc), iron phthalocyanine (abbreviation: FePc), tin phthalocyanine (abbreviation: SnPc), tin oxide phthalocyanine (abbreviation: SnOPc), titanium oxide phthalocyanine (abbreviation: TiOPc), vanadium oxide phthalocyanine (abbreviation: VOPc), etc., can be used. In particular, phthalocyanine-based metal complexes such as copper phthalocyanine or zinc phthalocyanine, or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2’,3’-c]phenazine are preferred.

[0145] For the electron injection buffer layer 119, substances with high electron injection properties such as alkali metals, alkaline earth metals, rare earth metals, and their compounds (including alkali metal compounds (oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates), or rare earth metal compounds (including oxides, halides, carbonates)) can be used.

[0146] Also, when the electron injection buffer layer 119 is formed by including a substance having electron transporting properties and a donor substance, as the donor substance, in addition to alkali metals, alkaline earth metals, rare earth metals, and their compounds (including alkali metal compounds (oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates), or rare earth metal compounds (including oxides, halides, carbonates)), organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, decamethylnickelocene, etc. can also be used. Note that as the substance having electron transporting properties, it can be formed using the same materials as those constituting the electron transport layer 114 described above.

[0147] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure. In this case, the layer in contact with the organic compound layer 103 functions as a cathode. As the material for forming the cathode, metals, alloys, electroconductive compounds, and mixtures thereof having a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), strontium (Sr), and alloys (MgAg, AlLi) and compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF 2 ) etc.) containing these, rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these. However, by providing an electron injection layer 115 or a thin film of a material having a small work function as described above between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium tin oxide containing silicon or silicon oxide, regardless of the magnitude of the work function, can be used as the cathode.

[0148] When the second electrode 102 is formed of a material having permeability to visible light, a light-emitting device that emits light from the second electrode 102 side can be obtained.

[0149] These conductive materials can be formed into a film using dry methods such as vacuum evaporation or sputtering, inkjet method, spin coating method, etc. Further, it may be formed by a wet method using the sol-gel method, or may be formed by a wet method using a paste of a metal material.

[0150] Also, as a method for forming the organic compound layer 103, various methods can be used regardless of dry methods or wet methods. For example, vacuum evaporation method, gravure printing method, offset printing method, screen printing method, inkjet method, spin coating method, etc. may be used.

[0151] Each of the above-described electrodes or each layer may be formed using different film-forming methods.

[0152] Next, an embodiment of a light-emitting device having a structure in which a plurality of light-emitting units are stacked (also referred to as a stacked element or a tandem element) will be described with reference to FIG. 1(C). This light-emitting device is a light-emitting device having a plurality of light-emitting units between an anode and a cathode. One light-emitting unit has substantially the same configuration as the organic compound layer 103 shown in FIG. 1(A). That is, it can be said that the light-emitting device shown in FIG. 1(C) is a light-emitting device having a plurality of light-emitting units, and the light-emitting devices shown in FIGS. 1(A) or 1(B) are light-emitting devices having one light-emitting unit.

[0153] In FIG. 1(C), between the first electrode 501 and the second electrode 502, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 respectively correspond to the first electrode 101 and the second electrode 102 in FIG. 1(A), and the same ones as those described in the description of FIG. 1(A) can be applied. Also, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same configuration or different configurations.

[0154] The charge generation layer 513 has a function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit when a voltage is applied to the first electrode 501 and the second electrode 502. That is, in FIG. 1(C), when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 may inject electrons into the first light-emitting unit 511 and holes into the second light-emitting unit 512.

[0155] The charge generation layer 513 is preferably formed with the same configuration as the charge generation layer 116 described in FIG. 1(B). Since the composite material of the organic compound and the metal oxide is excellent in carrier injection property and carrier transport property, low-voltage driving and low-current driving can be realized. When the surface on the anode side of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also serve as the hole injection layer of the light-emitting unit, so the light-emitting unit does not necessarily need to be provided with a hole injection layer.

[0156] Further, when the electron injection buffer layer 119 is provided in the charge generation layer 513, since the electron injection buffer layer 119 serves as the electron injection layer in the light-emitting unit on the anode side, it is not always necessary to form an electron injection layer in the light-emitting unit on the anode side.

[0157] In FIG. 1(C), the light-emitting device having two light-emitting units has been described, but the same can be similarly applied to a light-emitting device in which three or more light-emitting units are stacked. By arranging a plurality of light-emitting units between a pair of electrodes partitioned by the charge generation layer 513 as in the light-emitting device according to the present embodiment, high-brightness light emission can be enabled while keeping the current density low, and a longer-life element can be realized. In addition, a light-emitting device capable of low-voltage driving and having low power consumption can be realized.

[0158] Further, by making the emission colors of the respective light-emitting units different, light emission of a desired color can be obtained for the entire light-emitting device. For example, in a light-emitting device having two light-emitting units, by obtaining red and green emission colors in the first light-emitting unit and a blue emission color in the second light-emitting unit, it is also possible to obtain a white-light-emitting light-emitting device for the entire light-emitting device.

[0159] In addition, each layer and electrode such as the above-described organic compound layer 103, first light-emitting unit 511, second light-emitting unit 512, and charge generation layer can be formed using methods such as a vapor deposition method (including a vacuum vapor deposition method), a droplet ejection method (also referred to as an inkjet method), a coating method, a gravure printing method, etc. Further, they may contain a low-molecular material, a medium-molecular material (including an oligomer and a dendrimer), or a high-molecular material.

[0160] (Embodiment 3) In this embodiment, a display device manufactured using the light-emitting device described in Embodiment 1 and Embodiment 2 will be described with reference to FIG. 3. Note that FIG. 3(A) is a top view showing the display device, and FIG. 3(B) is a cross-sectional view obtained by cutting FIG. 3(A) along A-B and C-D. This display device includes a drive circuit portion (source line drive circuit) 601, a pixel portion 602, and a drive circuit portion (gate line drive circuit) 603, which are indicated by dotted lines, for controlling the light emission of the light-emitting device. Further, 604 is a sealing substrate, and 605 is a sealing material. The inside surrounded by the sealing material 605 is a space 607.

[0161] Note that the routing wiring 608 is a wiring for transmitting signals input to the source line drive circuit 601 and the gate line drive circuit 603, and receives a video signal, a clock signal, a start signal, a reset signal, etc. from an FPC (flexible printed circuit) 609 that serves as an external input terminal. Although only the FPC is illustrated here, a printed wiring board (PWB) may be attached to this FPC. The display device in this specification includes not only the display device main body but also a state in which an FPC or a PWB is attached thereto.

[0162] Next, the cross-sectional structure will be described with reference to FIG. 3(B). A drive circuit portion and a pixel portion are formed on the element substrate 610. Here, the source line drive circuit 601, which is a drive circuit portion, and one pixel in the pixel portion 602 are shown.

[0163] The element substrate 610 may be made of a substrate such as glass, quartz, organic resin, metal, alloy, semiconductor, etc., or may be made using a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, or the like.

[0164] The structure of the transistors used in the pixels and the drive circuits is not particularly limited. For example, it may be an inverted staggered transistor or a staggered transistor. Also, it may be a top gate transistor or a bottom gate transistor. The semiconductor material used for the transistors is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, etc. can be used. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In-Ga-Zn based metal oxide, may be used.

[0165] The crystallinity of the semiconductor material used for the transistors is also not particularly limited, and any of an amorphous semiconductor, a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal semiconductor, or a semiconductor having a crystal region in part) may be used. Using a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

[0166] Here, in addition to the transistors provided in the above pixels and drive circuits, for semiconductor devices such as transistors used in a touch sensor described later, it is preferable to apply an oxide semiconductor. In particular, it is preferable to apply an oxide semiconductor having a wider bandgap than silicon. By using an oxide semiconductor having a wider bandgap than silicon, the current in the off state of the transistor can be reduced.

[0167] The above oxide semiconductor preferably contains at least indium (In) or zinc (Zn). Further, it is more preferably an oxide semiconductor containing an oxide represented by In-M-Zn based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0168] In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor film having a plurality of crystal parts, wherein the c-axis of the crystal part is oriented perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there is no grain boundary between adjacent crystal parts.

[0169] By using such a material as the semiconductor layer, fluctuations in electrical characteristics can be suppressed, and a highly reliable transistor can be realized.

[0170] Also, due to its low off-current, the transistor having the above-described semiconductor layer can hold the charge accumulated in the capacitor through the transistor for a long period of time. By applying such a transistor to a pixel, it is also possible to stop the drive circuit while maintaining the gradation of the pixels displayed in each display area. As a result, an electronic device with extremely low power consumption can be realized.

[0171] For the purpose of stabilizing the characteristics of the transistor, etc., it is preferable to provide an underlayer film. As the underlayer film, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used, and it can be formed as a single layer or by lamination. The underlayer film can be formed using a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, an MOCVD (Metal Organic CVD) method, etc.), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, etc. Note that the underlayer film may not be provided if not necessary.

[0172] Note that FET623 indicates one of the transistors formed in the drive circuit section 601. Also, the drive circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment, a driver integrated type in which the drive circuit is formed on the substrate is shown, but this is not necessarily required, and the drive circuit can also be formed outside the substrate instead of on the substrate.

[0173] The pixel section 602 is formed by a plurality of pixels each including a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain thereof, but is not limited thereto, and may be a pixel section combining three or more FETs and a capacitive element.

[0174] Note that an insulator 614 is formed to cover the end of the first electrode 613. Here, it can be formed by using a positive photosensitive acrylic resin film.

[0175] Also, in order to make the coating property of an organic compound layer or the like formed later good, a curved surface having a curvature is formed at the upper end or the lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material of the insulator 614, it is preferable to provide a curved surface having a curvature radius (0.2 μm to 3 μm) only at the upper end of the insulator 614. Also, either a negative photosensitive resin or a positive photosensitive resin can be used as the insulator 614.

[0176] An organic compound layer 616 and a second electrode 617 are respectively formed on the first electrode 613. Here, as the material used for the first electrode 613 that functions as an anode, it is desirable to use a material having a large work function. For example, in addition to single-layer films such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 to 20 wt% of zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, a Pt film, etc., a laminate of a titanium nitride film and a film mainly composed of aluminum, a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film can be used. Note that when a laminated structure is used, the resistance as wiring is low, good ohmic contact can be achieved, and it can further function as an anode.

[0177] In addition, the organic compound layer 616 is formed by various methods such as vapor deposition using a vapor deposition mask, an inkjet method, and a spin coating method. The organic compound layer 616 includes the configuration as described in Embodiment 1 and Embodiment 2. Further, as other materials constituting the organic compound layer 616, a low molecular compound or a high molecular compound (including oligomers and dendrimers) may be used.

[0178] Furthermore, as the material used for the second electrode 617 formed on the organic compound layer 616 and functioning as a cathode, a material with a small work function (Al, Mg, Li, Ca, or their alloys and compounds (MgAg, MgIn, AlLi, etc.)) is preferably used. When the light generated in the organic compound layer 616 is transmitted through the second electrode 617, it is preferable to use a laminate of a thin metal film with a reduced film thickness and a transparent conductive film (ITO, indium oxide containing 2 to 20 wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0179] Note that a light-emitting device is formed by the first electrode 613, the organic compound layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in Embodiment 1 and Embodiment 2. Although the pixel portion is formed of a plurality of light-emitting devices, in the display device of the present embodiment, both the light-emitting devices described in Embodiment 1 and Embodiment 2 and light-emitting devices having other configurations may be mixed.

[0180] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, a structure is formed in which the light-emitting device 618 is provided in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. Note that the space 607 is filled with a filling material, and in addition to the case where an inert gas (nitrogen, argon, etc.) is filled, it may also be filled with a sealing material. It is a preferable configuration to form a recess in the sealing substrate and provide a drying material therein to suppress deterioration due to the influence of moisture.

[0181] Note that it is preferable to use an epoxy resin and glass frit for the sealing material 605. Further, it is desirable that these materials are materials that hardly permeate moisture and oxygen. As the material used for the sealing substrate 604, in addition to a glass substrate and a quartz substrate, a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, or the like can be used.

[0182] Although not shown in FIG. 3, a protective film may be provided on the second electrode. The protective film may be formed of an organic resin film or an inorganic insulating film. Further, the protective film may be formed so as to cover the exposed portion of the sealing material 605. Further, the protective film can be provided so as to cover the exposed side surfaces of the surfaces and side surfaces of the pair of substrates, the sealing layer, the insulating layer, and the like.

[0183] For the protective film, a material that hardly permeates impurities such as water can be used. Therefore, it is possible to effectively suppress the diffusion of impurities such as water from the outside to the inside.

[0184] As the material constituting the protective film, oxides, nitrides, fluorides, sulfides, ternary compounds, metals, polymers, or the like can be used. For example, materials containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, or indium oxide, materials containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, materials containing nitrides containing titanium and aluminum, oxides containing titanium and aluminum, oxides containing aluminum and zinc, sulfides containing manganese and zinc, sulfides containing cerium and strontium, oxides containing erbium and aluminum, oxides containing yttrium and zirconium, or the like can be used.

[0185] The protective film is preferably formed using a film formation method with good step coverage. One such method is the atomic layer deposition (ALD) method. It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, a protective film that is dense, has reduced defects such as cracks and pinholes, or has a uniform thickness can be formed. Also, the damage to the processing member when forming the protective film can be reduced.

[0186] For example, by forming the protective film using the ALD method, a protective film that is uniform and has few defects can be formed on the surface with a complex uneven shape, the upper surface, side surfaces, and back surface of the touch panel.

[0187] As described above, a display device manufactured using the light-emitting devices described in Embodiment 1 and Embodiment 2 can be obtained.

[0188] Since the display device in this embodiment uses the light-emitting devices described in Embodiment 1 and Embodiment 2, a display device with good characteristics can be obtained. Specifically, since the light-emitting devices described in Embodiment 1 and Embodiment 2 have high luminous efficiency, it is possible to obtain a display device with low power consumption. Also, since the light-emitting devices described in Embodiment 1 and Embodiment 2 have good reliability, a display device with good reliability can be obtained. In addition, since the light-emitting devices described in Embodiment 1 and Embodiment 2 can be made into light-emitting devices with good chromaticity and color purity, a display device with good display quality can be obtained.

[0189] Also, this embodiment can be freely combined with other embodiments.

[0190] (Embodiment 4) As illustrated in FIGS. 4(A) and 4(B), a plurality of light-emitting devices 130 are formed on an insulating layer 175 to constitute a display device. In the present embodiment, a display device according to another aspect of the present invention will be described in detail.

[0191] The display device 100 has a pixel portion 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0192] In this specification and the like, when explaining matters common to, for example, the sub-pixel 110R, the sub-pixel 110G, and the sub-pixel 110B, they may be referred to as the sub-pixel 110 for explanation. For other components distinguished by alphabets, when explaining matters common to them, symbols with omitted alphabets may be used for explanation.

[0193] The sub-pixel 110R exhibits red light, the sub-pixel 110G exhibits green light, and the sub-pixel 110B exhibits blue light. Thereby, an image can be displayed on the pixel portion 177. In the present embodiment, three-color sub-pixels of red (R), green (G), and blue (B) are described as an example, but combinations of sub-pixels of other colors may also be used. Further, the number of sub-pixels is not limited to three and may be four or more. Examples of four sub-pixels include four-color sub-pixels of R, G, B, and white (W), four-color sub-pixels of R, G, B, and Y, and four sub-pixels of R, G, B, and infrared light (IR).

[0194] In this specification and the like, the row direction may be referred to as the X direction and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0195] In FIG. 4(A), an example is shown in which sub-pixels of different colors are arranged side by side in the X direction, and sub-pixels of the same color are arranged side by side in the Y direction. Note that sub-pixels of different colors may be arranged side by side in the Y direction, and sub-pixels of the same color may be arranged side by side in the X direction.

[0196] Outside the pixel portion 177, a connection portion 140 is provided, and an area 141 may be provided. When the area 141 is provided, the area 141 is provided between the pixel portion 177 and the connection portion 140. When the area 141 is provided, an organic compound layer is provided in the area 141. Further, a conductive layer 151C is provided in the connection portion 140.

[0197] In FIG. 4(A), an example where the area 141 and the connection portion 140 are located on the right side of the pixel portion 177 is shown, but the positions of the area 141 and the connection portion 140 are not particularly limited. Further, the area 141 and the connection portion 140 may be singular or plural.

[0198] FIG. 4(B) is an example of a cross-sectional view between the dashed-dotted lines A1 - A2 in FIG. 4(A). As shown in FIG. 4(B), the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and on the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is provided on a substrate (not shown). Openings reaching the conductive layer 172 are provided in the insulating layer 175, the insulating layer 174, and the insulating layer 173, and plugs 176 are provided so as to fill the openings.

[0199] In the pixel portion 177, a light-emitting device 130 is provided on the insulating layer 175 and the plug 176. Further, a protective layer 131 is provided so as to cover the light-emitting device 130. A substrate 120 is bonded by a resin layer 122 on the protective layer 131. Further, it is preferable that an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0200] In FIG. 4(B), a plurality of cross-sections of the inorganic insulating layer 125 and the insulating layer 127 are shown, but when the display device 100 is viewed from above, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are each connected into one.

[0201] In FIG. 4(B), light-emitting devices 130R, 130G, and 130B are shown as the light-emitting device 130. The light-emitting devices 130R, 130G, and 130B shall emit light of different colors. For example, the light-emitting device 130R can emit red light, the light-emitting device 130G can emit green light, and the light-emitting device 130B can emit blue light. Also, the light-emitting device 130R, 130G, or 130B may emit other visible light or infrared light.

[0202] The display device according to one aspect of the present invention can be a top emission type that emits light in a direction opposite to the substrate on which the light-emitting device is formed, for example. Note that the display device according to one aspect of the present invention may be a bottom emission type.

[0203] The light-emitting device 130R includes a first electrode 101R (pixel electrode) composed of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer 104. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103R during processing.

[0204] The light-emitting device 130G includes a first electrode 101G (pixel electrode) composed of a conductive layer 151G and a conductive layer 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 102 on the common layer 104. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103G during processing.

[0205] The light-emitting device 130B has a configuration as shown in Embodiment 1 and Embodiment 2. It includes a first electrode 101B (pixel electrode) composed of a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer 104. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103B during processing. Also, when the common layer 104 is provided, the laminated structure of the organic compound layer 103B and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 1 and Embodiment 2.

[0206] Note that the common layer 104 is preferably an electron injection layer or an electron transport layer, and more preferably an electron injection layer. Also, when it is an electron transport layer, the electron transport layer preferably has a laminated structure, and among the laminated layers, the layer on the second electrode side is the common layer 104 and the layer on the light-emitting layer side is the organic compound layer 103 is more preferable.

[0207] Also, since the light-emitting devices 130R and 130G are also light-emitting devices manufactured through a photolithography process, a light-emitting device with a low driving voltage can be obtained in which an increase in the driving voltage due to the photolithography process is suppressed.

[0208] Among the pixel electrode and the common electrode of the light-emitting device 130, one functions as an anode and the other functions as a cathode. Hereinafter, unless otherwise specified, it will be described assuming that the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0209] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent and island-shaped for each light-emitting device or for each emission color. By providing the organic compound layer 103 in an island shape for each light-emitting device 130, it is possible to suppress the leakage current between adjacent light-emitting devices 130 even in a high-definition display device. Thereby, crosstalk can be prevented, and a display device with extremely high contrast can be realized. In particular, a display device with high current efficiency at low luminance can be realized.

[0210] The island-shaped organic compound layer 103 is formed by forming an organic compound film and processing the organic compound film using a photolithography method.

[0211] The organic compound layer 103 is preferably provided so as to cover the upper surface and the side surface of the first electrode (pixel electrode) of the light-emitting device 130. Thereby, it becomes easier to increase the aperture ratio of the display device 100 compared to a configuration in which the end portion of the organic compound layer 103 is located inside the end portion of the pixel electrode. Further, by covering the side surface of the pixel electrode of the light-emitting device 130 with the organic compound layer 103, it is possible to suppress the contact between the pixel electrode and the second electrode 102, and thus to suppress a short circuit of the light-emitting device 130.

[0212] Further, in the display device according to one aspect of the present invention, it is preferable that the first electrode (pixel electrode) of the light-emitting device has a laminated structure. For example, in the example shown in FIG. 4(B), the first electrode of the light-emitting device 130 has a laminated structure of a conductive layer 151 and a conductive layer 152.

[0213] As the conductive layer 151, for example, a metal material can be used. Specifically, for example, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), etc., and alloys containing these appropriately combined can also be used.

[0214] As the conductive layer 152, an oxide having any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, it is preferable to use a conductive oxide containing any one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and thus can be suitably used as the conductive layer 152.

[0215] The conductive layer 151 may have a laminated structure of a plurality of layers having different materials, and the conductive layer 152 may also have a laminated structure of a plurality of layers having different materials. In this case, the conductive layer 151 may have a layer using a material that can be used for the conductive layer 152 such as a conductive oxide, and the conductive layer 152 may also have a layer using a material that can be used for the conductive layer 151 such as a metal material. For example, when the conductive layer 151 has a laminated structure of two or more layers, the layer in contact with the conductive layer 152 can be a layer using a material that can be used for the conductive layer 152.

[0216] Note that the side surface of the conductive layer 151 preferably has a tapered shape. Specifically, the side surface of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By making the side surface of the conductive layer 152 tapered, the covering property of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be enhanced.

[0217] Subsequently, an example of a method for manufacturing the display device 100 having the configuration shown in FIG. 4(A) will be described with reference to FIGS. 5 to 10.

[0218] [Example of manufacturing method 1] The thin films (such as insulating films, semiconductor films, and conductive films) that constitute the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, or the like.

[0219] In addition, the thin films (such as insulating films, semiconductor films, and conductive films) that constitute the display device can be formed by wet film-forming methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0220] In addition, when processing the thin films that constitute the display device, for example, it can be processed using a photolithography method.

[0221] In the photolithography method, as the light used for exposure, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light obtained by mixing these can be used. In addition, ultraviolet light, KrF laser light, ArF laser light, or the like can also be used. Further, exposure may be performed by a liquid immersion exposure technique. In addition, as the light used for exposure, extreme ultra-violet (EUV) light, or X-rays may be used. In addition, instead of the light used for exposure, an electron beam can also be used.

[0222] For the etching of the thin film, a dry etching method, a wet etching method, a sandblasting method, or the like can be used.

[0223] First, as shown in FIG. 5(A), an insulating layer 171 is formed on a substrate (not shown). Subsequently, a conductive layer 172 and a conductive layer 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layer 172 and the conductive layer 179. Subsequently, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0224] As the substrate, a substrate having heat resistance sufficient to withstand at least subsequent heat treatment can be used. For example, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, a single crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or a semiconductor substrate such as an SOI substrate can be used.

[0225] Subsequently, as shown in FIG. 5(A), an opening reaching the conductive layer 172 is formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Subsequently, a plug 176 is formed so as to fill the opening.

[0226] Subsequently, as shown in FIG. 5(A), a conductive film 151f that will later become the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, and the conductive layer 151C, and a conductive film 152f that will later become the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the conductive layer 152C are formed on the plug 176 and the insulating layer 175. As the conductive film 151f, for example, a metal material can be used. As the conductive film 152f, for example, an oxide having any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used.

[0227] Subsequently, as shown in FIG. 5(A), a resist mask 191 is formed on the conductive film 152f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and performing exposure and development.

[0228] Subsequently, as shown in FIG. 5(B), for example, the conductive film 151f and the conductive film 152f in a region that does not overlap with the resist mask 191 are removed. Thereby, the conductive layer 151 and the conductive layer 152 are formed.

[0229] Subsequently, as shown in FIG. 5(C), the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0230] Subsequently, as shown in FIG. 5(D), an insulating film 156f that will later become the insulating layer 156R, insulating layer 156G, insulating layer 156B, and insulating layer 156C is formed on the conductive layer 152R, conductive layer 152G, conductive layer 152B, conductive layer 152C, and insulating layer 175.

[0231] For the insulating film 156f, an inorganic insulating film such as an oxide insulating film, nitride insulating film, oxynitride insulating film, or nitroxide insulating film, for example, silicon oxynitride can be used.

[0232] Subsequently, as shown in FIG. 5(E), the insulating film 156f is processed to form the insulating layer 156R, insulating layer 156G, insulating layer 156B, and insulating layer 156C.

[0233] Subsequently, as shown in FIG. 6(A), an organic compound film 103Rf is formed on the conductive layer 152R, conductive layer 152G, conductive layer 152B, and insulating layer 175. Note that, as shown in FIG. 6(A), the organic compound film 103Rf is not formed on the conductive layer 152C.

[0234] Subsequently, as shown in FIG. 6(A), a sacrificial film 158Rf and a mask film 159Rf are formed.

[0235] By providing the sacrificial film 158Rf on the organic compound film 103Rf, the damage received by the organic compound film 103Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be enhanced.

[0236] For the sacrificial film 158Rf, a film with high resistance to the processing conditions of the organic compound film 103Rf, specifically, a film with a large etching selectivity ratio with respect to the organic compound film 103Rf is used. For the mask film 159Rf, a film with a large etching selectivity ratio with respect to the sacrificial film 158Rf is used.

[0237] Further, the sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Rf. As the substrate temperature when forming the sacrificial film 158Rf and the mask film 159Rf, typically, it is respectively 100°C or higher and 200°C or lower, preferably 100°C or higher and 150°C or lower, more preferably 100°C or higher and 120°C or lower. Since the light-emitting device according to one aspect of the present invention contains the first organic compound, it is possible to provide a display device with good display quality even after undergoing a heating process at a higher temperature.

[0238] For the sacrificial film 158Rf and the mask film 159Rf, it is preferable to use a film that can be removed by a wet etching method or a dry etching method.

[0239] Note that the sacrificial film 158Rf formed in contact with the organic compound film 103Rf is preferably formed using a formation method that causes less damage to the organic compound film 103Rf than the mask film 159Rf. For example, the ALD method (Atomic Layer Deposition method) or the vacuum evaporation method is preferable to the sputtering method.

[0240] As the sacrificial film 158Rf and the mask film 159Rf, respectively, for example, one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, and an inorganic insulating film can be used.

[0241] For the sacrificial film 158Rf and the mask film 159Rf, respectively, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing the metal materials can be used. In particular, it is preferable to use a low melting point material such as aluminum or silver. By using a metal material capable of shielding ultraviolet rays for one or both of the sacrificial film 158Rf and the mask film 159Rf, it is possible to suppress the organic compound film 103Rf from being irradiated with ultraviolet rays during pattern exposure, and thus it is possible to suppress the deterioration of the organic compound film 103Rf, which is preferable.

[0242] In addition, for the sacrificial film 158Rf and the mask film 159Rf, metal oxides such as indium-gallium-zinc oxide, indium oxide, indium-zinc oxide, indium-tin oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and indium tin oxide containing silicon can be used respectively.

[0243] Note that in the above metal oxides, instead of gallium, an element M (M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used.

[0244] As the sacrificial film 158Rf and the mask film 159Rf, for example, it is preferable to use a semiconductor material such as silicon or germanium because it has a high affinity with the semiconductor manufacturing process. Alternatively, a compound containing the above semiconductor material can be used.

[0245] In addition, as the sacrificial film 158Rf and the mask film 159Rf, various inorganic insulating films can be used respectively. In particular, the oxide insulating film is preferable because it has a higher adhesion to the organic compound film 103Rf than the nitride insulating film.

[0246] Subsequently, as shown in FIG. 6(A), a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and performing exposure and development.

[0247] The resist mask 190R is provided at a position overlapping the conductive layer 152R. The resist mask 190R is preferably also provided at a position overlapping the conductive layer 152C. Thereby, it is possible to suppress the conductive layer 152C from being damaged during the manufacturing process of the display device.

[0248] Subsequently, as shown in FIG. 6(B), using the resist mask 190R, a part of the mask film 159Rf is removed to form the mask layer 159R. The mask layer 159R remains on the conductive layer 152R and on the conductive layer 152C. Thereafter, the resist mask 190R is removed. Subsequently, using the mask layer 159R as a mask (also referred to as a hard mask), a part of the sacrificial film 158Rf is removed to form the sacrificial layer 158R.

[0249] By using the wet etching method, compared with the case of using the dry etching method, damage to the organic compound film 103Rf during the processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced. When using the wet etching method, for example, it is preferable to use a chemical solution such as a developer, an alkaline aqueous solution such as an aqueous solution of tetramethylammonium hydroxide (TMAH), a dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof.

[0250] Also, when using the dry etching method in the processing of the sacrificial film 158Rf, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0251] The resist mask 190R can be removed in the same manner as the resist mask 191.

[0252] Subsequently, as shown in FIG. 6(B), the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, using the mask layer 159R and the sacrificial layer 158R as hard masks, a part of the organic compound film 103Rf is removed to form the organic compound layer 103R.

[0253] As a result, as shown in FIG. 6(B), a laminated structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R. Also, the conductive layer 152G and the conductive layer 152B are exposed.

[0254] The processing of the organic compound film 103Rf is preferably performed by anisotropic etching. In particular, anisotropic dry etching is preferred. Alternatively, wet etching may be used.

[0255] When using the dry etching method, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0256] Also, a gas containing oxygen may be used as the etching gas. By the etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining the etching rate at a sufficient speed. For this reason, damage to the organic compound film 103Rf can be suppressed. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed.

[0257] When using the dry etching method, for example, H 2 , CF 4 , C 4 F 8 , SF 6 , CHF 3 , Cl 2 , H 2 O, BCl 3 , or a gas containing one or more of Group 18 elements such as He and Ar is preferably used as the etching gas. Alternatively, it is preferable to use one or more of these and a gas containing oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas.

[0258] Subsequently, as shown in FIG. 7(A), an organic compound film 103Gf that will later become the organic compound layer 103G is formed.

[0259] The organic compound film 103Gf can be formed by the same method as the method that can be used to form the organic compound film 103Rf. Also, the organic compound film 103Gf can have the same configuration as the organic compound film 103Rf.

[0260] Subsequently, as shown in FIG. 7(A), a sacrificial film 158Gf and a mask film 159Gf are formed in sequence. Then, a resist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as the conditions applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190G are the same as the conditions applicable to the resist mask 190R.

[0261] The resist mask 190G is provided at a position overlapping with the conductive layer 152G.

[0262] Subsequently, as shown in FIG. 7(B), using the resist mask 190G, a part of the mask film 159Gf is removed to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Subsequently, using the mask layer 159G as a mask, a part of the sacrificial film 158Gf is removed to form a sacrificial layer 158G. Subsequently, the organic compound film 103Gf is processed to form an organic compound layer 103G.

[0263] Subsequently, as shown in FIG. 7(C), an organic compound film 103Bf is formed.

[0264] The organic compound film 103Bf can be formed by the same method as that used for forming the organic compound film 103Rf. Also, the organic compound film 103Bf can have the same configuration as the organic compound film 103Rf.

[0265] Subsequently, as shown in FIG. 7(C), a sacrificial film 158Bf and a mask film 159Bf are formed in sequence. Then, a resist mask 190B is formed. The materials and formation methods of the sacrificial film 158Bf and the mask film 159Bf are the same as the conditions applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190B are the same as the conditions applicable to the resist mask 190R.

[0266] The resist mask 190B is provided at a position overlapping with the conductive layer 152B.

[0267] Subsequently, as shown in FIG. 7(D), using the resist mask 190B, a part of the mask film 159Bf is removed to form the mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Thereafter, the resist mask 190B is removed. Subsequently, using the mask layer 159B as a mask, a part of the sacrificial film 158Bf is removed to form the sacrificial layer 158B. Subsequently, the organic compound film 103Bf is processed to form the organic compound layer 103B. For example, using the mask layer 159B and the sacrificial layer 158B as hard masks, a part of the organic compound film 103Bf is removed to form the organic compound layer 103B.

[0268] As a result, as shown in FIG. 7(D), a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B. Also, the mask layer 159R and the mask layer 159G are exposed.

[0269] Note that the side surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are preferably perpendicular or substantially perpendicular to the formation surface. For example, it is preferable that the angle formed by the formation surface and these side surfaces is 60 degrees or more and 90 degrees or less.

[0270] As described above, the distance between two adjacent ones of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B formed by the photolithography method can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between two opposing end portions of two adjacent ones among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. By narrowing the distance between the island-shaped organic compound layers in this way, a display device having high fineness and a large aperture ratio can be provided. Also, the distance between the first electrodes between adjacent light-emitting devices can be narrowed and can be, for example, 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less. Note that the distance between the first electrodes between adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0271] Subsequently, as shown in FIG. 8(A), it is preferable to remove the mask layer 159R, the mask layer 159G, and the mask layer 159B.

[0272] For the mask layer removal process, the same method as the mask film processing process can be used. In particular, by using the wet etching method, the damage to the organic compound layer 103 can be reduced when removing the mask layer compared to the case of using the dry etching method.

[0273] Alternatively, the mask layer may be removed by dissolving it in a polar solvent such as water or alcohol. Examples of alcohol include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0274] After removing the mask layer, a drying process may be performed to remove the water adsorbed on the surface. For example, heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 120°C or lower, as the substrate temperature. A reduced pressure atmosphere is preferable because drying can be performed at a lower temperature.

[0275] Subsequently, as shown in FIG. 8(B), an inorganic insulating film 125f is formed.

[0276] Subsequently, as shown in FIG. 8(C), an insulating film 127f that will later become the insulating layer 127 is formed on the inorganic insulating film 125f.

[0277] When forming the inorganic insulating film 125f and the insulating film 127f, the substrate temperature is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0278] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above-mentioned substrate temperature range.

[0279] The inorganic insulating film 125f is preferably formed, for example, by using the ALD method. Using the ALD method is preferable because film formation damage can be reduced and a film with high coating properties can be formed. As the inorganic insulating film 125f, for example, it is preferable to form an aluminum oxide film by using the ALD method.

[0280] The insulating film 127f is preferably formed by using the above-mentioned wet film formation method. The insulating film 127f is preferably formed, for example, by spin coating using a photosensitive material, and more specifically, it is preferably formed by using a photosensitive resin composition containing an acrylic resin.

[0281] Subsequently, exposure is performed to expose a part of the insulating film 127f to visible light or ultraviolet light. The insulating layer 127 is formed in a region sandwiched between any two of the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B, and around the conductive layer 152C.

[0282] The width of the insulating layer 127 to be formed later can be controlled by the exposure region of the insulating film 127f. In the present embodiment, processing is performed so that the insulating layer 127 has a portion overlapping with the upper surface of the conductive layer 151.

[0283] The light used for exposure preferably includes i-line (wavelength 365 nm). Also, the light used for exposure may include at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0284] Subsequently, as shown in FIG. 9(A), development is performed to remove the exposed region of the insulating film 127f and form the insulating layer 127a.

[0285] Subsequently, as shown in FIG. 9(B), using the insulating layer 127a as a mask, an etching process is performed to remove a part of the inorganic insulating film 125f and reduce the film thickness of a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. As a result, an inorganic insulating layer 125 is formed under the insulating layer 127a. In addition, the surfaces of the portions where the film thicknesses of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B are thin are exposed. Hereinafter, the etching process using the insulating layer 127a as a mask may be referred to as the first etching process.

[0286] The first etching process can be performed by dry etching or wet etching. When the inorganic insulating film 125f is formed using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, it is preferable because the first etching process can be performed in a batch.

[0287] When performing dry etching, it is preferable to use a chlorine-based gas. As the chlorine-based gas, Cl 2 , BCl 3 , SiCl 4 , and CCl 4 etc. can be used alone or in combination of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, argon gas, etc. can be appropriately added to the above chlorine-based gas alone or in combination of two or more gases. By using dry etching, regions with thin film thicknesses of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can be formed with good in-plane uniformity.

[0288] As the dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. As the dry etching apparatus having a high-density plasma source, for example, an inductively coupled plasma (ICP) etching apparatus can be used. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes can be used.

[0289] Also, it is preferable to perform the first etching process by wet etching. By using the wet etching method, damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared to the case of using the dry etching method. For example, wet etching can be performed using an alkaline solution. For example, TMAH, which is an alkaline solution, can be used for wet etching of an aluminum oxide film. Also, an acid solution containing fluoride can be used. In this case, wet etching can be performed by a paddle method. Note that when the inorganic insulating film 125f is formed using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, it is preferable because the above etching process can be performed collectively.

[0290] In the first etching process, the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B are not completely removed, and the etching process is stopped with the film thickness reduced. In this way, by leaving the corresponding sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B on the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, it is possible to prevent the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from being damaged in the subsequent process.

[0291] Subsequently, it is preferable to expose the entire substrate and irradiate the insulating layer 127a with visible light or ultraviolet light. The energy density of the exposure is preferably greater than 0 mJ / cm 2 and less than or equal to 800 mJ / cm 2 More preferably, it is greater than 0 mJ / cm 2 and less than or equal to 500 mJ / cm 2 Performing such exposure after development may improve the transparency of the insulating layer 127a. Also, in some cases, it may be possible to lower the substrate temperature required for the heat treatment to deform the insulating layer 127a into a tapered shape in a subsequent process.

[0292] Here, as the sacrificial layers 158R, 158G, and 158B, the presence of a barrier insulating layer against oxygen (for example, an aluminum oxide film or the like) can reduce the diffusion of oxygen into the organic compound layers 103R, 103G, and 103B.

[0293] Subsequently, a heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be deformed into an insulating layer 127 having a tapered shape on the side surface (FIG. 9(C)). The heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 130°C or lower. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. Also, the heating atmosphere may be an atmospheric pressure atmosphere or a reduced pressure atmosphere. Thereby, the adhesion between the insulating layer 127 and the inorganic insulating layer 125 can be improved, and the corrosion resistance of the insulating layer 127 can also be improved.

[0294] In the first etching process, by not completely removing the sacrificial layers 158R, 158G, and 158B but leaving the sacrificial layers 158R, 158G, and 158B in a state where the film thickness is reduced, it is possible to prevent the organic compound layers 103R, 103G, and 103B from being damaged and deteriorated in the heat treatment. Therefore, the reliability of the light-emitting device can be enhanced.

[0295] Subsequently, as shown in FIG. 10(A), using the insulating layer 127 as a mask, an etching process is performed to remove a part of the sacrificial layers 158R, 158G, and 158B. Thereby, openings are formed in each of the sacrificial layers 158R, 158G, and 158B, and the upper surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C are exposed. Hereinafter, this etching process may be referred to as the second etching process.

[0296] The end of the inorganic insulating layer 125 is covered with the insulating layer 127. Further, in FIG. 10(A), an example is shown in which a part of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered with the insulating layer 127, and the tapered portion formed by the second etching process is exposed.

[0297] The second etching process is performed by wet etching. By using the wet etching method, the damage applied to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced as compared with the case of using the dry etching method. Wet etching can be performed using, for example, an alkaline solution or an acidic solution. It is preferably an aqueous solution so that the organic compound layer 103 does not dissolve.

[0298] Subsequently, as shown in FIG. 10(B), a common electrode 155 is formed on the organic compound layer 103R, on the organic compound layer 103G, on the organic compound layer 103B, on the conductive layer 152C, and on the insulating layer 127. The common electrode 155 can be formed by a method such as a sputtering method or a vacuum evaporation method.

[0299] Subsequently, as shown in FIG. 10(C), a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by a method such as a vacuum evaporation method, a sputtering method, a CVD method, or an ALD method.

[0300] Subsequently, the display device can be manufactured by bonding the substrate 120 onto the protective layer 131 using the resin layer 122. As described above, in the method for manufacturing a display device according to one aspect of the present invention, the insulating layer 156 is provided so as to have a region overlapping with the side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. Thereby, the yield of the display device can be increased and the occurrence of defects can be suppressed.

[0301] As described above, in the method for manufacturing a display device according to one aspect of the present invention, the island-shaped organic compound layer 103R, the island-shaped organic compound layer 103G, and the organic compound layer 103B are not formed using a fine metal mask, but are formed by processing after forming a film on one surface. Therefore, the island-shaped layers can be formed with a uniform thickness. And a high-definition display device or a display device with a high aperture ratio can be realized. Also, even when the fineness or aperture ratio is high and the distance between sub-pixels is extremely short, it is possible to suppress the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from contacting each other in adjacent sub-pixels. Therefore, it is possible to suppress the generation of leakage current between sub-pixels. Thereby, crosstalk can be prevented, and a display device with extremely high contrast can be realized. Also, even in a display device having a tandem-type light-emitting device manufactured using a photolithography method, a display device with good characteristics can be provided.

[0302] (Embodiment 5) In the present embodiment, a display device according to one aspect of the present invention will be described.

[0303] The display device of the present embodiment can be a high-definition display device. Therefore, the display device of the present embodiment can be used, for example, in the display unit of information terminal devices (wearable devices) such as wristwatch type and bracelet type, as well as in VR devices such as head-mounted displays (HMDs) and display units of wearable devices that can be worn on the head such as glasses-type AR devices.

[0304] Also, the display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used, for example, in electronic devices having a relatively large screen such as television devices, desktop or notebook personal computers, monitors for computers, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, and audio playback devices.

[0305] [Display module] FIG. 11(A) shows a perspective view of the display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any one of the display devices 100B to 100E described later.

[0306] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display unit 281. The display unit 281 is an area for displaying an image in the display module 280, and is an area where light from each pixel provided in the pixel unit 284 described later can be visually recognized.

[0307] FIG. 11(B) shows a perspective view schematically showing the configuration on the substrate 291 side. On the substrate 291, a circuit unit 282, a pixel circuit unit 283 on the circuit unit 282, and a pixel unit 284 on the pixel circuit unit 283 are stacked. In addition, a terminal unit 285 for connecting to the FPC 290 is provided in a portion that does not overlap with the pixel unit 284 on the substrate 291. The terminal unit 285 and the circuit unit 282 are electrically connected by a wiring unit 286 formed of a plurality of wirings.

[0308] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of FIG. 11(B). Various configurations described in the previous embodiment can be applied to the pixel 284a.

[0309] The pixel circuit unit 283 includes a plurality of pixel circuits 283a arranged periodically.

[0310] One pixel circuit 283a is a circuit that controls the driving of a plurality of elements included in one pixel 284a.

[0311] The circuit unit 282 has a circuit for driving each pixel circuit 283a of the pixel circuit unit 283. For example, it preferably has one or both of a gate line driving circuit and a source line driving circuit. In addition, it may have at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0312] The FPC 290 functions as a wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit unit 282. Also, an IC may be mounted on the FPC 290.

[0313] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, so that the aperture ratio (effective display area ratio) of the display unit 281 can be made extremely high.

[0314] Such a display module 280 is extremely high-definition, and thus can be suitably used for VR devices such as HMDs or glasses-type AR devices. For example, even in the case of a configuration in which the display unit of the display module 280 is viewed through a lens, since the display module 280 has an extremely high-definition display unit 281, pixels cannot be viewed even when the display unit is enlarged by the lens, and a highly immersive display can be performed. In addition, the display module 280 is not limited to this, and can be suitably used for electronic devices having a relatively small display unit.

[0315] [Display device 100A] The display device 100A shown in FIG. 12(A) has a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0316] The substrate 301 corresponds to the substrate 291 in FIGS. 12(A) and 12(B). The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single crystal silicon substrate can be used. The transistor 310 has a part of the substrate 301, a conductive layer 311, a low resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or a drain. The insulating layer 314 is provided to cover the side surface of the conductive layer 311.

[0317] Also, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0318] Also, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0319] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a dielectric of the capacitor 240.

[0320] The conductive layer 241 is provided on the insulating layer 261 and is embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 via the insulating layer 243.

[0321] Covering a capacity of 240, an insulating layer 255 is provided, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. On the insulating layer 175, a light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are provided. An insulator is provided in the region between adjacent light-emitting devices.

[0322] An insulating layer 156R is provided so as to have a region overlapping with the side surface of the conductive layer 151R, an insulating layer 156G is provided so as to have a region overlapping with the side surface of the conductive layer 151G, and an insulating layer 156B is provided so as to have a region overlapping with the side surface of the conductive layer 151B. Also, a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided so as to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided so as to cover the conductive layer 151B and the insulating layer 156B. A sacrificial layer 158R is located on the organic compound layer 103R, a sacrificial layer 158G is located on the organic compound layer 103G, and a sacrificial layer 158B is located on the organic compound layer 103B.

[0323] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source or drain of the transistor 310 by a plug 256 embedded in the insulating layer 243, the insulating layer 255, the insulating layer 174, and the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plug.

[0324] Also, a protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. On the protective layer 131, a substrate 120 is bonded by a resin layer 122. Details of the components from the light-emitting device 130 to the substrate 120 can be referred to in Embodiment 4. The substrate 120 corresponds to the substrate 292 in FIG. 11(A).

[0325] FIG. 12(B) is a modified example of the display device 100A shown in FIG. 12(A). The display device shown in FIG. 12(B) has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has a region overlapping with one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. In the display device shown in FIG. 12(B), the light-emitting device 130 can emit, for example, white light. Also, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light.

[0326] [Display device 100B] FIG. 13 shows a perspective view of the display device 100B, and FIG. 14 shows a cross-sectional view of the display device 100C.

[0327] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In FIG. 13, the substrate 352 is shown by a dashed line.

[0328] The display device 100B has a pixel portion 177, a connection portion 140, a circuit 356, a wiring 355, etc. FIG. 13 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in FIG. 13 can also be referred to as a display module having the display device 100B, an IC (integrated circuit), and an FPC. Here, a display device in which a connector such as an FPC is attached to the substrate of the display device, or a display device in which an IC is mounted on the substrate is called a display module.

[0329] The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 may be singular or plural. The connection portion 140 has the common electrode of the light-emitting device and the conductive layer electrically connected thereto, and can supply a potential to the common electrode.

[0330] As the circuit 356, for example, a scanning line driving circuit can be used.

[0331] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0332] FIG. 13 shows an example in which the IC 354 is provided on the substrate 351 by a COG (Chip On Glass) method, a COF (Chip on Film) method, or the like. As the IC 354, for example, an IC having a scanning line driving circuit, a signal line driving circuit, or the like can be applied. Note that the display device 100B and the display module may be configured not to include an IC. Further, the IC may be mounted on the FPC by, for example, a COF method.

[0333] FIG. 14 shows an example of a cross section when a part of the region including the FPC 353, a part of the circuit 356, a part of the pixel portion 177, a part of the connection portion 140, and a part of the region including the end portion of the display device 100B in FIG. 13 are each cut.

[0334] [Display device 100C] The display device 100C shown in FIG. 14 includes a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, a light-emitting device 130B that emits blue light, etc. between the substrate 351 and the substrate 352.

[0335] Details of the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B can be referred to in Embodiment 4.

[0336] The light-emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. The light-emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. The light-emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B.

[0337] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. An insulating layer 156R is provided so as to have a region in contact with the side surface of the conductive layer 151R, and a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R.

[0338] For the conductive layer 224G, the conductive layer 151G, the conductive layer 152G, the insulating layer 156G in the light-emitting device 130G, and the conductive layer 224B, the conductive layer 151B, the conductive layer 152B, the insulating layer 156B in the light-emitting device 130B, since they are the same as the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, and the insulating layer 156R in the light-emitting device 130R, detailed descriptions thereof are omitted.

[0339] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. The layer 128 is embedded in the recesses.

[0340] The layer 128 has a function of filling and planarizing the recesses of the conductive layers 224R, 224G, and 224B. On the conductive layers 224R, 224G, and 224B and the layer 128, conductive layers 151R, 151G, and 151B that are electrically connected to the conductive layers 224R, 224G, and 224B are provided. Therefore, the region overlapping the recesses of the conductive layers 224R, 224G, and 224B can also be used as a light-emitting region, and the aperture ratio of the pixel can be increased.

[0341] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and particularly preferably formed using an organic insulating material. For example, the organic insulating material that can be used for the aforementioned insulating layer 127 can be applied to the layer 128.

[0342] A protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. The protective layer 131 and the substrate 352 are adhered via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. For encapsulating the light-emitting device 130, a solid encapsulation structure, a hollow encapsulation structure, or the like can be applied. In FIG. 14, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid encapsulation structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow encapsulation structure may be applied. At this time, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Further, the space may be filled with a resin different from the adhesivelayer 142 provided in a frame shape.

[0343] In FIG. 14, an example is shown in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. Further, FIG. 14 shows an example in which an insulating layer 156C is provided so as to have a region overlapping with the side surface of the conductive layer 151C.

[0344] The display device 100C is a top emission type. The light emitted from the light-emitting device is emitted toward the substrate 352 side. It is preferable to use a material having high transmittance for visible light for the substrate 352. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0345] On the substrate 351, an insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided in this order. A part of the insulating layer 211 functions as a gate insulating layer of each transistor. A part of the insulating layer 213 functions as a gate insulating layer of each transistor. The insulating layer 215 is provided to cover the transistors. The insulating layer 214 is provided to cover the transistors and has a function as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0346] As the insulating layer 211, the insulating layer 213, and the insulating layer 215, it is preferable to use an inorganic insulating film respectively.

[0347] An organic insulating layer is suitable for the insulating layer 214 that functions as a planarization layer.

[0348] The transistor 201 and the transistor 205 include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate.

[0349] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 via the conductive layer 166 and the connection layer 242. The conductive layer 166 is shown as an example having a laminated structure of a conductive film obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive film obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive film obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. Thereby, the connection portion 204 and the FPC 353 can be electrically connected via the connection layer 242.

[0350] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 on the side of the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, at the connection portion 140, and in the circuit 356 and the like. In addition, various optical members can be arranged outside the substrate 352.

[0351] As the substrates 351 and 352, materials that can be used for the substrate 120 can be applied respectively.

[0352] As the adhesive layer 142, materials that can be used for the resin layer 122 can be applied.

[0353] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

[0354] [Display device 100D] The display device 100D shown in FIG. 15 is mainly different from the display device 100C shown in FIG. 14 in that it is a bottom emission type display device.

[0355] The light emitted by the light-emitting device is emitted toward the substrate 351 side. It is preferable to use a material with high transmittance for visible light for the substrate 351. On the other hand, the light transmittance of the material used for the substrate 352 is not limited.

[0356] It is preferable to form a light-shielding layer 317 between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. In FIG. 15, an example is shown in which a light-shielding layer 317 is provided on the substrate 351, an insulating layer 153 is provided on the light-shielding layer 317, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0357] The light-emitting device 130R has a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0358] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0359] For the conductive layers 112R, 112B, 126R, 126B, 129R, and 129B, materials with high transparency to visible light are used respectively. It is preferable to use a material that reflects visible light for the second electrode 102.

[0360] In addition, in FIG. 15, although the light-emitting device 130G is not shown, the light-emitting device 130G is also provided.

[0361] Also, in FIG. 15 and the like, an example is shown in which the upper surface of the layer 128 has a flat portion, but the shape of the layer 128 is not particularly limited.

[0362] [Display device 100D2] The display device 100D2 shown in FIG. 16 is an example of a bottom emission type display device different from the display device 100D shown in FIG. 15. The display device 100D2 is different from the display device 100D in that it has an organic resin layer 180. In the figure, the reference numerals of the same components as those in FIG. 15 may be omitted, and the details thereof may be referred to the description of FIG. 15.

[0363] Also, FIG. 16(B) shows the top layout of the pixel 178 (pixel 178a and pixel 178b) having sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, sub-pixel 110W), and FIG. 16(C) shows a top view of the organic resin layer 180 in the region where the sub-pixels 110R and 110G included in the pixel 178 are formed. The width between the light-shielding layers 317 is the width 110Rw in the light-emitting region of the sub-pixel 110R.

[0364] As shown in FIG. 16(A), the organic resin layer 180 is provided on the insulating layer 214. As shown in the region surrounded by the dashed-dotted line in FIG. 16(A) and FIG. 16(C), the organic resin layer 180 has concave portions 181 (concave portion 181a, concave portion 181b) having a curved surface in at least a region where sub-pixels are formed. Note that the concave portion 181 may be provided outside the light-emitting region like the concave portion 181c. By providing the concave portion 181c, light generated in the region overlapping with the light-shielding layer 317 or light that has traveled to the region overlapping with the light-shielding layer 317 is refracted and can be extracted from the light-emitting region, so that the light-emitting efficiency can be improved.

[0365] A plurality of the concave portions 181 may be formed in a matrix. The concave portion 181a and the concave portion 181b may be provided in contact with each other or may have a flat surface therebetween.

[0366] In FIG. 16, the upper surface shape of the concave portion is shown as a hexagon (FIG. 16(C)) and the cross-sectional shape is shown as a semi-circle (FIG. 16(A)), but other shapes may be used as necessary. For example, as the upper surface shape of the concave portion, polygons such as a triangle, a quadrilateral (including a rectangle and a square), a pentagon, and the like, a shape in which the corners of these polygons are rounded, an ellipse, or a circle can be mentioned.

[0367] As the organic resin layer 180, an insulating layer having an organic material can be used. For example, as the organic resin layer 180, an acrylic resin, a polyimide resin, an epoxy resin, an imide resin, a polyamide resin, a polyimide amide resin, a silicone resin, a siloxane resin, a benzocyclobutene-based resin, a phenol resin, and precursors of these resins can be applied. Further, as the organic resin layer 180, an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or an alcohol-soluble polyamide resin may be used.

[0368] In addition, a photosensitive resin can be used as the organic resin layer 180. A photoresist may be used as the photosensitive resin. As the photosensitive resin, a positive-type material or a negative-type material can be used.

[0369] The organic resin layer 180 may contain a material that absorbs visible light. For example, the organic resin layer 180 itself may be composed of a material that absorbs visible light, or the organic resin layer 180 may contain a pigment that absorbs visible light. As the organic resin layer 180, for example, a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix can be used.

[0370] In addition, a first electrode 101 (first electrodes 101R and 101W) is provided on the organic resin layer 180, and an organic compound layer 103 is provided on the first electrode 101. The ends of the first electrode 101 and the organic compound layer 103 may be covered with an insulating layer 127.

[0371] In addition, the first electrode 101 formed on the organic resin layer 180 has a recess similarly along the recess of the organic resin layer 180. Further, the organic compound layer 103 formed on the first electrode 101 has a recess similarly along the recess of the first electrode 101. Further, the common layer 104 formed on the organic compound layer 103 has a recess similarly along the recess of the organic compound layer 103. Further, the second electrode 102 formed on the common layer 104 has a recess similarly along the recess of the common layer 104. That is, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have a structure that overlaps each other.

[0372] In addition, a common layer 104 is provided on the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is provided on the common layer 104. A protective layer 131 is provided on the second electrode 102, and the structure is bonded to the substrate 352 via an adhesive layer 142.

[0373] Note that in FIG. 16, the light-emitting devices 130G and 130B are not shown, but the light-emitting devices 130G and 130B are also provided.

[0374] The light-emitting device according to one embodiment of the present invention having the organic resin layer 180 as described above contains the organic compound represented by the general formula (Gh1) in the organic compound layer 103 as described in Embodiment 1. Therefore, due to the effect of the organic resin layer 180 and the inseparable effect of the organic semiconductor device using the organic compound of the present application, an organic semiconductor device with high luminous efficiency can be provided, so that an organic semiconductor device with good reliability, low driving voltage, and low power consumption can be provided.

[0375] [Display device 100E] The display device 100E shown in FIG. 17 is a modified example of the display device 100C shown in FIG. 14, and is mainly different from the display device 100C in that it has a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0376] In the display device 100E, the light-emitting device 130 has a region that overlaps with one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. The coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can be provided on the surface of the substrate 351 on the side of the substrate 352. The ends of the coloring layer 132R, the ends of the coloring layer 132G, and the ends of the coloring layer 132B can overlap with the light-shielding layer 157.

[0377] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Further, for example, the coloring layer 132R can transmit red light, the coloring layer 132G can transmit green light, and the coloring layer 132B can transmit blue light. Note that the display device 100E may be configured such that the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B are provided between the protective layer 131 and the adhesive layer 142.

[0378] [Display device 100E2] The display device 100E2 shown in FIG. 18 is a modified example of the display device 100E shown in FIG. 17, and has microlenses 182 on the color layers 132R, 132G, and 132B. In the figure, the reference numerals of the same components as those in FIG. 17 may be omitted, and the details thereof may be referred to the description of FIG. 17.

[0379] Further, FIG. 18(B) shows the top layout of the pixels 178 (pixels 178a and 178b) having sub-pixels 110 (sub-pixels 110R, sub-pixels 110G, and sub-pixels 110B), and FIG. 18(C) shows a top view of the microlenses 182 in the region where the sub-pixels 110R and 110G included in the pixel 178 are formed. Note that the region where the common electrode 155 contacts the organic compound layer 103 is the width 110Gw in the light-emitting region of the sub-pixel 110G.

[0380] The display device 100E2 shown in FIG. 18(A) is provided with a planarization film 143 on the protective layer 131, and the color layers 132R, 132G, and 132B are provided on the planarization film 144. A planarization film 144 is provided so as to cover the color layers 132R, 132G, and 132B. The microlenses 182 are provided on the planarization film 144.

[0381] Note that as shown in FIG. 18(C), the microlenses 182 may be provided for each sub-pixel in the region where the sub-pixels are formed.

[0382] In FIG. 18(C), the top shape of the microlens 182 is shown as a hexagon, but it may be other shapes as required. For example, as the top shape of the concave portion, polygons such as a triangle, a quadrilateral (including a rectangle and a square), a pentagon, etc., a shape in which the corners of these polygons are rounded, an ellipse, or a circle can be mentioned.

[0383] The microlenses 182 can be formed using the same material as the organic resin layer 180.

[0384] The light-emitting device according to one embodiment of the present invention having the microlens 182 as described above includes an organic compound represented by the general formula (Gh1) in the organic compound layer 103 as described in Embodiment 1. Therefore, due to the effect of the microlens 182 and the inseparable effect of the organic semiconductor device using the organic compound of the present application, an organic semiconductor device with high luminous efficiency can be provided, so that an organic semiconductor device suitable for mobile applications with good reliability, low driving voltage, and low power consumption can be provided.

[0385] This embodiment can be appropriately combined with other embodiments or examples. Also, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be appropriately combined.

[0386] (Embodiment 6) In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0387] The electronic device of this embodiment has a display device according to one embodiment of the present invention in the display unit. The display device according to one embodiment of the present invention has low power consumption and high reliability. Therefore, it can be used in the display units of various electronic devices.

[0388] Examples of the electronic device include, for example, television devices, desktop or notebook personal computers, monitors for computers, digital signage, large game machines such as pachinko machines, and other electronic devices with relatively large screens, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, audio playback devices, and the like.

[0389] An example of a wearable device that can be worn on the head will be described with reference to FIGS. 19(A) to 19(D).

[0390] The electronic device 700A shown in FIG. 19(A) and the electronic device 700B shown in FIG. 19(B) each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting parts 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0391] The display device according to one aspect of the present invention can be applied to the display panel 751. Therefore, a highly reliable electronic device can be obtained.

[0392] The electronic device 700A and the electronic device 700B can each project the image displayed on the display panel 751 onto the display area 756 of the optical member 753. Since the optical member 753 has translucency, the user can view the image displayed in the display area superimposed on the transmitted image viewed through the optical member 753.

[0393] The electronic device 700A and the electronic device 700B may each be provided with a camera capable of imaging the front as an imaging unit. Further, the electronic device 700A and the electronic device 700B can each detect the orientation of the user's head by including an acceleration sensor such as a gyro sensor, and display an image corresponding to the orientation in the display area 756.

[0394] The communication unit has a wireless communication device, and the wireless communication device can supply, for example, a video signal. Note that instead of or in addition to the wireless communication device, a connector to which a cable for supplying a video signal and a power potential can be connected may be provided.

[0395] Further, the electronic device 700A and the electronic device 700B are each provided with a battery, which can be charged by one or both of wireless and wired means.

[0396] The housing 721 may be provided with a touch sensor module.

[0397] As the touch sensor module, various touch sensors can be applied. For example, various methods such as the capacitance method, the resistive film method, the infrared method, the electromagnetic induction method, the surface acoustic wave method, or the optical method can be adopted. In particular, it is preferable to apply a capacitance method or an optical method sensor to the touch sensor module.

[0398] The electronic device 800A shown in FIG. 19(C) and the electronic device 800B shown in FIG. 19(D) each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0399] The display device of one aspect of the present invention can be applied to the display unit 820. Therefore, a highly reliable electronic device can be obtained.

[0400] The display unit 820 is provided at a position inside the housing 821 where it can be visually recognized through the lens 832. Also, by displaying different images on the pair of display units 820, three-dimensional display using parallax can also be performed.

[0401] It is preferable that the electronic device 800A and the electronic device 800B each have a mechanism capable of adjusting the left and right positions of the lens 832 and the display unit 820 so that they are in optimal positions according to the position of the user's eyes.

[0402] The user can wear the electronic device 800A or the electronic device 800B on the head by the mounting unit 823.

[0403] The imaging unit 825 has a function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Also, a plurality of cameras may be provided so as to be compatible with a plurality of viewing angles such as telephoto and wide angle.

[0404] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone.

[0405] The electronic device 800A and the electronic device 800B may each have an input terminal. A video signal from a video output device or the like and a cable for supplying power for charging a battery provided in the electronic device can be connected to the input terminal.

[0406] The electronic device according to one aspect of the present invention may have a function of performing wireless communication with the earphone 750.

[0407] Further, the electronic device may have an earphone unit. The electronic device 700B shown in FIG. 19(B) has an earphone unit 727. A part of the wiring connecting the earphone unit 727 and the control unit may be arranged inside the housing 721 or the mounting unit 723.

[0408] Similarly, the electronic device 800B shown in FIG. 19(D) has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be configured to be wired to each other.

[0409] Thus, as the electronic device according to one aspect of the present invention, either the glasses type (such as the electronic device 700A and the electronic device 700B) or the goggle type (such as the electronic device 800A and the electronic device 800B) is suitable.

[0410] The electronic device 6500 shown in FIG. 20(A) is a portable information terminal that can be used as a smartphone.

[0411] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display unit 6502 has a touch panel function.

[0412] The display device according to one aspect of the present invention can be applied to the display unit 6502. Therefore, a highly reliable electronic device can be obtained.

[0413] FIG. 20(B) is a schematic cross-sectional view including the end of the housing 6501 on the side of the microphone 6506.

[0414] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0415] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0416] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0417] The display device according to one aspect of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, it is possible to mount a large-capacity battery 6518 while suppressing the thickness of the electronic device. Further, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow bezel can be realized.

[0418] An example of a television device is shown in FIG. 20(C). The television device 7100 has a display unit 7000 incorporated in a housing 7171. Here, a configuration in which the housing 7171 is supported by a stand 7173 is shown.

[0419] The display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be obtained.

[0420] The operation of the television apparatus 7100 shown in FIG. 20(C) can be performed by operation switches provided in the housing 7171 and a separate remote control operation unit 7151.

[0421] FIG. 20(D) shows an example of a notebook personal computer. The notebook personal computer 7200 has a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated in the housing 7211.

[0422] The display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be obtained.

[0423] FIGS. 20(E) and 20(F) show an example of a digital signage.

[0424] The digital signage 7300 shown in FIG. 20(E) has a housing 7301, a display unit 7000, a speaker 7303, etc. Further, it can have an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0425] FIG. 20(F) shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0426] In FIGS. 20(E) and 20(F), the display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be obtained.

[0427] The larger the display unit 7000 is, the larger the amount of information that can be provided at one time can be increased. Also, the larger the display unit 7000 is, the easier it is for people's eyes to notice, and for example, the advertising effect can be enhanced.

[0428] Also, as shown in FIGS. 20(E) and 20(F), it is preferable that the digital signage 7300 or the digital signage 7400 can be linked by wireless communication with an information terminal 7311 such as a smartphone or an information terminal 7411 held by a user.

[0429] The electronic device shown in FIGS. 21(A) to 21(G) includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, and the like.

[0430] The electronic device shown in FIGS. 21(A) to 21(G) has various functions. For example, it can have a function of displaying various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date or time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, and the like.

[0431] Details of the electronic device shown in FIGS. 21(A) to 21(G) will be described below.

[0432] FIG. 21(A) is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used, for example, as a smartphone. Note that the portable information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, or the like. Further, the portable information terminal 9171 can display character and image information on its plurality of surfaces. FIG. 21(A) shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mail, SNS, and telephone, titles of e-mail or SNS, sender names, dates, times, remaining battery levels, radio wave intensities, and the like. Alternatively, an icon 9050 or the like may be displayed at the position where the information 9051 is displayed.

[0433] FIG. 21(B) is a perspective view showing a portable information terminal 9172. The portable information terminal 9172 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces, respectively. For example, the user can also check the information 9053 displayed at a position where it can be observed from above the portable information terminal 9172 in a state where the portable information terminal 9172 is stored in the breast pocket of the clothing.

[0434] FIG. 21(C) is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 can execute various applications such as a mobile phone, e-mail, text viewing and creation, music playback, Internet communication, and computer games, as an example. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front surface of the housing 9000, and an operation key 9005 as an operation button on the left side surface of the housing 9000, and a connection terminal 9006 on the bottom surface.

[0435] FIG. 21(D) is a perspective view showing a wristwatch-type portable information terminal 9200. The portable information terminal 9200 can be used as, for example, a smartwatch (registered trademark). Further, the display unit 9001 is provided with a curved display surface, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can also make a hands-free call by mutually communicating with, for example, a wirelessly communicable headset. Further, the portable information terminal 9200 can also perform data transmission and charging mutually with other information terminals via the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0436] FIGS. 21(E) to 21(G) are perspective views showing a foldable portable information terminal 9201. Further, FIG. 21(E) shows a state in which the portable information terminal 9201 is unfolded, FIG. 21(G) shows a folded state, and FIG. 21(F) is a perspective view of a state in the middle of changing from one of FIGS. 21(E) and 21(G) to the other. The portable information terminal 9201 has excellent portability in the folded state and excellent display listability due to a seamless wide display area in the unfolded state. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0437] This embodiment can be appropriately combined with other embodiments or examples. Further, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be appropriately combined.

Example

[0438] In this example, a manufacturing method and characteristics of a light-emitting device 1 which is a light-emitting device according to one aspect of the present invention and comparative light-emitting devices 1-1 to 1-3 which are comparative light-emitting devices will be described in detail. Structural formulas of main compounds used in the light-emitting device 1 and the comparative light-emitting devices 1-1 to 1-3 are shown below.

[0439] [Chemical formula]

[0440] (Method for manufacturing a light-emitting device 1) First, 70 nm of indium tin oxide (ITSO) containing silicon oxide was laminated on a glass substrate by sputtering to form a first electrode 101 with a size of 2 mm × 2 mm. Note that the first electrode 101 functions as an anode.

[0441] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0442] Thereafter, the substrate was introduced into a vacuum evaporation apparatus whose internal pressure was reduced to about 1×10 -4 Pa. After performing vacuum baking at 170 °C for 30 minutes in the heating chamber of the vacuum evaporation apparatus, the substrate was allowed to cool for about 30 minutes.

[0443] Next, with the surface on which the first electrode 101 is formed facing downward, the substrate was fixed to a holder provided in the vacuum evaporation apparatus, and N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) containing fluorine with a molecular weight of 672 were co-evaporated at a weight ratio of 1:0.1 (=BBABnf:OCHD-003) to form a hole injection layer 111.

[0444] BBABnf was evaporated onto the hole injection layer 111 to a thickness of 30 nm to form a first hole transport layer. Subsequently, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) represented by the above structural formula (ii) was evaporated to a thickness of 5 nm to form a second hole transport layer, thereby forming a hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0445] Subsequently, on the hole transport layer 112, 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole-1,2,3,4,5,6,7,8,1’,2’,3’,4’,5’,6’,7’,8’-d 16 )(abbreviation: SiTrzCz2-d16), 9-[3-(triphenylsilyl)phenyl]-3,9’-(bi-9H-carbazole-d 15 )(abbreviation: PSiCzCz-d15), and (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI) represented by the above structural formula (v) were co-evaporated at a weight ratio of 0.435:0.435:0.13 (=SiTrzCz2-d16:PSiCzCz-d15:PtON-TBBI) to a thickness of 35 nm to form the light-emitting layer 113.

[0446] After that, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) represented by the above structural formula (vi) was evaporated to a thickness of 5 nm to form the first electron transport layer. Subsequently, mSiTrz and lithium 8-quinolinolate (abbreviation: Liq) represented by the above structural formula (vii) were co-evaporated at a weight ratio of 1:1 to a thickness of 20 nm to form the second electron transport layer, thereby forming the electron transport layer 114.

[0447] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115. Thereafter, aluminum (Al) was evaporated to a thickness of 200 nm to form the second electrode 102.

[0448] Subsequently, in a glove box under a nitrogen atmosphere, an operation of sealing with a glass substrate was performed so that the light-emitting device was not exposed to the atmosphere (application of a UV-curable sealing material around the element, treatment of irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 °C for 1 hour under atmospheric pressure), and the light-emitting device 1 was formed.

[0449] (Method for manufacturing comparative light-emitting device 1-1) Comparative light-emitting device 1-1 was manufactured in the same manner as light-emitting device 1, except that SiTrzCz2-d16 in light-emitting device 1 was changed to 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2) represented by the above structural formula (viii), and PSiCzCz-d15 was changed to PSiCzCz.

[0450] (Method for manufacturing comparative light-emitting device 1-2) Comparative light-emitting device 1-2 was manufactured in the same manner as light-emitting device 1, except that PSiCzCz-d15 in light-emitting device 1 was changed to PSiCzCz.

[0451] (Method for manufacturing comparative light-emitting device 1-3) Comparative light-emitting device 1-3 was manufactured in the same manner as light-emitting device 1, except that SiTrzCz2-d16 in light-emitting device 1 was changed to SiTrzCz2.

[0452] The device structures of light-emitting device 1 and comparative light-emitting devices 1-1 to 1-3 are shown below.

[0453]

Table 1

[0454]

Table 2

[0455] Here, PSiCzCz and SiTrzCz2 are organic compounds in which the deuteriums of PSiCzCz-d15 and SiTrzCz2-d16 are hydrogen, respectively.

[0456] Note that on a quartz substrate, a thin film of SiTrzCz2-d16, a thin film of PSiCzCz-d15, and a mixed film co-evaporated such that the weight ratio of SiTrzCz2-d16 and PSiCzCz-d15 is 1:1 with a film thickness of 50 nm were each deposited, and the PL spectra of the deposited films are shown in Fig. 62. For the measurement of the PL spectrum, a spectrofluorometer (FP-8600DS manufactured by JASCO Corporation) was used. As shown in Fig. 62, the PL spectrum of the mixed film is located at a longer wavelength than the PL spectra of the individual films, indicating that SiTrzCz2-d16 and PSiCzCz-d15 form an exciplex.

[0457] The phosphorescence lifetimes of PSiCzCz, PSiCzCz-d15, SiTrzCz2, and SiTrzCz2-d16, and the magnification by which the phosphorescence lifetime changes due to deuteration are shown below. The product of the respective magnifications was 1.40. The excitation wavelength of PSiCzCz and PSiCzCz-d15 was 340 nm, and the measurement wavelength was 440 nm. The excitation wavelength of SiTrzCz2 and SiTrzCz2-d16 was 330 nm, and the measurement wavelength was 450 nm.

[0458]

Table 3

[0459] The phosphorescence lifetime was defined as the time from when the light intensity reached 50% of the initial measurement value (t = 0) until the light intensity decayed to 1 / e of the value at t = 0, as measured from the measurement data as shown in Fig. 2. In Fig. 2, a graph was created with the time when the measurement data reached 50% of the initial measurement intensity as time 0 s, and when the light intensity at 0 s was set to 1, the time when the light intensity became 1 / e was defined as the phosphorescence lifetime.

[0460] The measurement was carried out at the liquid nitrogen temperature (77 K) by installing a PMU-830 type liquid nitrogen cooling unit in the FP-8600 manufactured by JASCO Corporation, Japan.

[0461] The solution preparation of the material was carried out in a glove box of LABstarM13 (1250 / 780) manufactured by MBRAUN. The sample was dissolved in 2-MeTHF that had been freeze-degassed, and a solution with a concentration of 1.2E -4 M was prepared. The prepared solution was put into a liquid sample cell for cooling (sample tube) of the LPH-140 type manufactured by JASCO Corporation. After attaching the sample tube holder and the fixing nut, it was capped. When the Dewar of the cooling unit of the FP-8600 was filled with liquid nitrogen and ready, the sample cell was taken out of the glove box and attached to the Dewar containing liquid nitrogen of the apparatus for cooling.

[0462] The sample cell was irradiated with excitation light for about 30 seconds. After blocking the excitation light with a shutter, time-resolved measurement was carried out by measuring the intensity of the luminescence that decayed at 10 ms intervals. The wavelength for performing the phosphorescence lifetime measurement was selected as a wavelength with as little fluorescence as possible by comparing the emission spectra in the phosphorescence mode and the fluorescence mode. Although the excitation wavelength can be selected appropriately, it is preferably measured at 330 nm. Also, the bandwidths of the excitation light and the measurement light may be about 10 nm. Ideally, since the luminescence decays as a single exponential function, the time from when the light amount becomes 50% of that at the start of measurement until the luminescence intensity decays to 1 / e can be defined as the phosphorescence lifetime.

[0463] Also, the T 1 level of PSiCzCz-d15 is 2.97 eV, and the T 1 level of SiTrzCz2-d16 is 2.93 eV, and the difference between them is 0.04 eV.

[0464] T 1The level was calculated by measuring the emission spectrum (phosphorescence spectrum) at a measurement temperature of 10 K using a thin film formed by depositing a 50-nm sample on a quartz substrate. The measurement was performed using a microscopic PL device, LabRAM HR-PL (manufactured by Horiba, Ltd.), with a He-Cd laser (325 nm) as the excitation light. The emission end was calculated at the value where the slope on the short-wavelength side of the peak (or shoulder peak) observed at the shortest wavelength of the emission spectrum (phosphorescence spectrum) was the maximum, as shown in FIGS. 61(A) and 61(B), by drawing a tangent line and calculating from the intersection of the tangent line with the horizontal axis (wavelength) or the baseline.

[0465] The 5% weight loss temperature of PSiCzCz-d15 at 10 Pa was 254°C, and the 5% weight loss temperature of SiTrzCz2-d16 at 10 Pa was 298°C, with a difference of 45°C.

[0466] The 5% weight loss temperature refers to the temperature at which the weight obtained from thermogravimetric measurement becomes -5% of the starting weight when the pressure is controlled to be either 1.0×10 -1 Pa or more and 10 Pa or less, and the weight of the compound used in the measurement is 1 mg or more and 20 mg or less. A high-vacuum differential type differential thermal balance (TG-DTA2410SA, manufactured by Bruker AXS K.K.) was used for the measurement, and the measurement was performed under the conditions of a pressure of 10 Pa, a heating rate of 10°C / min, and a nitrogen gas flow (flow rate: 30 mL / min). In this example, the sample weight was set to approximately 3.00 mg (from 2.95 mg to 3.06 mg).

[0467] Further, FIG. 63 shows a figure in which the photoluminescence (PL) spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 shown in FIG. 62 is overlaid with the PL spectrum of the polymer-dispersed film of PtON-TBBI. As shown in FIG. 63, the PL spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 and the PL spectrum of the polymethyl methacrylate (abbreviation: PMMA)-dispersed film of PtON-TBBI have an overlap, and the difference in the maximum peak wavelength of each is 30 nm or less. The PMMA-dispersed film of PtON-TBBI uses deoxygenated dichloromethane as a solvent, and a solution in which PtON-TBBI is dispersed at a concentration of 1.0 wt% with respect to PMMA is formed into a film on a quartz substrate by the drop-casting method, and dried at room temperature for 30 minutes under a nitrogen stream in a glove box. The emission spectrum of the obtained PMMA-dispersed film of PtON-TBBI was measured using an absolute PL quantum yield measuring device (Quantaurus-QY C11347-01 manufactured by Hamamatsu Photonics).

[0468] The luminance-current density characteristics of the light-emitting device 1 and the comparative light-emitting devices 1-1 to 1-3 are shown in FIG. 22, the current efficiency-current density characteristics are shown in FIG. 23, the luminance-voltage characteristics are shown in FIG. 24, the current density-voltage characteristics are shown in FIG. 25, the external quantum efficiency-luminance characteristics are shown in FIG. 26, the blue index (BI)-current density characteristics are shown in FIG. 27, and the electroluminescence spectrum is shown in FIG. 28.

[0469] Also, the voltage, current, current density, CIE chromaticity, current efficiency, external quantum efficiency, and blue index (BI) values in the vicinity of 1000 cd / cm 2 are shown below. For the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, a spectro-radiometer (SR-UL1R manufactured by Topcon Corporation) was used and the measurement was performed at room temperature.

[0470] Note that the blue index (BI) is a value obtained by dividing the current efficiency (cd / A) by the y chromaticity calculated in the CIE1931 color system, and is one of the indexes representing the emission characteristics of blue light emission. In blue light emission, the smaller the y chromaticity, the higher the color purity of the light emission tends to be. By using blue light emission with a small y chromaticity and high color purity, it becomes possible to represent blue in a wide chromaticity range in a display, and since the luminance of blue necessary for representing white in the display decreases, an effect of reducing the power consumption of the display can be obtained. Therefore, BI, which is the current efficiency considering the y chromaticity as one of the indexes of blue purity, may be used as a means for representing the efficiency of blue light emission, and it can be said that the higher the BI, the better the efficiency as a blue light emitting device in the display.

[0471]

Table 4

[0472] From FIGS. 22 to 28 and Table 4, it was found that the light emitting device 1 and the comparative light emitting devices 1-1 to 1-3 are all light emitting devices showing good initial characteristics driven at equivalent light emission efficiency and voltage. Also, it was found that the light emitting device 1 and the comparative light emitting devices 1-1 to 1-3 all have a peak wavelength of the electroluminescence spectrum of 464 nm and show blue light emission derived from PtON-TBBI.

[0473] On the other hand, the normalized luminance time change characteristics of the light emitting device 1 and the comparative light emitting devices 1-1 to 1-3 at a current density of 10 mA / cm 2 are shown in FIG. 29.

[0474] From FIG. 29, it was found that the light emitting device 1 according to one aspect of the present invention is a light emitting device with a small time change of the normalized luminance and good reliability as compared with the comparative light emitting devices 1-1 to 1-3.

Example

[0475] In this embodiment, the manufacturing method and characteristics of the light-emitting device 2, which is a light-emitting device according to one aspect of the present invention, and the comparative light-emitting devices 2-1 to 2-3, which are comparative light-emitting devices, will be described in detail. The structural formulas of the main compounds used in the light-emitting device 2 and the comparative light-emitting devices 2-1 to 2-3 are shown below.

[0476] [Chemical formula]

[0477] (Manufacturing method of the light-emitting device 2) First, 70 nm of indium tin oxide (ITSO) containing silicon oxide was laminated on a glass substrate by sputtering to form the first electrode 101 with a size of 2 mm × 2 mm. Note that the first electrode 101 functions as an anode.

[0478] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0479] Thereafter, the substrate was introduced into a vacuum evaporation apparatus whose internal pressure was reduced to about 1×10 -4 Pa, and in the heating chamber of the vacuum evaporation apparatus, vacuum baking was performed at 170 °C for 30 minutes, and then the substrate was allowed to cool for about 30 minutes.

[0480] Next, with the surface on which the first electrode 101 is formed facing downward, the substrate was fixed to a holder provided in the vacuum evaporation apparatus, and N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) containing fluorine with a molecular weight of 672 were co-evaporated in a weight ratio of 1:0.1 (=BBABnf:OCHD-003) by 10 nm on the inorganic insulating film and the first electrode 101 to form a hole injection layer 111.

[0481] On the positive hole injection layer 111, 30 nm of BBABnf was deposited to form the first hole transport layer. Subsequently, 9-[3-(triphenylsilyl)phenyl]-3,9’-(bi-9H-carbazole-d 15 )(abbreviation: PSiCzCz-d15) of 5 nm was deposited to form the second hole transport layer, thereby forming the hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0482] Subsequently, on the hole transport layer 112, 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole-1,2,3,4,5,6,7,8,1’,2’,3’,4’,5’,6’,7’,8’-d 16 )(abbreviation: SiTrzCz2-d16), PSiCzCz-d15, and (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI) represented by the above structural formula (v) were co-deposited at 35 nm so that the weight ratio was 0.435:0.435:0.13 (=SiTrzCz2-d16:PSiCzCz-d15:PtON-TBBI) to form the light-emitting layer 113.

[0483] After that, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) represented by the above structural formula (vi) was deposited to 5 nm to form the first electron transport layer. Subsequently, mSiTrz and lithium 8-quinolinolate (abbreviation: Liq) represented by the above structural formula (vii) were co-deposited at 20 nm so that the weight ratio was 1:1 to form the second electron transport layer, thereby forming the electron transport layer 114.

[0484] Subsequently, lithium fluoride (LiF) was deposited to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was deposited to a thickness of 200 nm to form the second electrode 102.

[0485] Subsequently, in a glove box under a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate so as not to be exposed to the atmosphere (operation of applying a UV curable sealing material around the element, irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 ° C for 1 hour under atmospheric pressure), and the light-emitting device 2 was formed.

[0486] (Fabrication method of comparative light-emitting device 2-1) The comparative light-emitting device 2-1 was fabricated in the same manner as the light-emitting device 2, except that SiTrzCz2-d16 in the light-emitting device 2 was changed to 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2) represented by the above structural formula (viii), and PSiCzCz-d15 was changed to 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) represented by the above structural formula (ii).

[0487] (Fabrication method of comparative light-emitting device 2-2) The comparative light-emitting device 2-2 was fabricated in the same manner as the light-emitting device 2, except that PSiCzCz-d15 in the light-emitting device 2 was changed to PSiCzCz.

[0488] (Fabrication method of comparative light-emitting device 2-3) The comparative light-emitting device 2-3 was fabricated in the same manner as the light-emitting device 2, except that SiTrzCz2-d16 in the light-emitting device 2 was changed to SiTrzCz2.

[0489] The device structures of the light-emitting device 2 and the comparative light-emitting devices 2-1 to 2-3 are shown below.

[0490]

Table 5

[0491]

Table 6

[0492] Here, PSiCzCz and SiTrzCz2 are organic compounds in which the deuteriums of PSiCzCz-d15 and SiTrzCz2-d16 are hydrogen, respectively.

[0493] Note that a thin film of SiTrzCz2-d16, a thin film of PSiCzCz-d15, and a mixed film co-evaporated such that the weight ratio of SiTrzCz2-d16 and PSiCzCz-d15 is 1:1 with a film thickness of 50 nm on a quartz substrate were each deposited, and the PL spectra of the deposited films are shown in FIG. 62. For the measurement of the PL spectrum, a spectrofluorometer (FP-8600DS manufactured by JASCO Corporation) was used. As shown in FIG. 62, the PL spectrum of the mixed film is located at a longer wavelength than the PL spectra of the individual films, and it was found that SiTrzCz2-d16 and PSiCzCz-d15 form an exciplex.

[0494] The phosphorescence lifetimes of PSiCzCz, PSiCzCz-d15, SiTrzCz2, and SiTrzCz2-d16, and the magnification by which the phosphorescence lifetime changed due to deuteration are shown below. Also, the product of the respective magnifications was 1.40. Note that the excitation wavelength of PSiCzCz and PSiCzCz-d15 was 340 nm, and the measurement wavelength was 440 nm. The excitation wavelength of SiTrzCz2 and SiTrzCz2-d16 was 330 nm, and the measurement wavelength was 450 nm.

[0495]

Table 7

[0496] Also, the T of PSiCzCz-d15 1 level is 2.97 eV, and the T of SiTrzCz2-d16 1 level is 2.93 eV, and the difference therebetween is 0.04 eV.

[0497] Also, the 5% weight loss temperature of PSiCzCz-d15 at 10 Pa was 254 °C, and the 5% weight loss temperature of SiTrzCz2-d16 at 10 Pa was 298 °C, and the difference was 45 °C.

[0498] In addition, the phosphorescence lifetime, T 1 The levels and 5% weight loss temperature were calculated in the same manner as in Example 1.

[0499] Also, Fig. 63 shows a diagram in which the photoluminescence (PL) spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 shown in Fig. 62 is overlapped with the PL spectrum of the polymer dispersion film of PtON-TBBI. As shown in Fig. 63, the PL spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 and the PL spectrum of the polymethyl methacrylate (abbreviation: PMMA) dispersion film of PtON-TBBI have an overlap, and the difference in the maximum peak wavelength of each is 30 nm or less. The PMMA dispersion film of PtON-TBBI was prepared in the same manner as in Example 1.

[0500] The luminance-current density characteristics of light-emitting device 2 and comparative light-emitting devices 2-1 to 2-3 are shown in Fig. 30, the current efficiency-current density characteristics are shown in Fig. 31, the luminance-voltage characteristics are shown in Fig. 32, the current density-voltage characteristics are shown in Fig. 33, the external quantum efficiency-luminance characteristics are shown in Fig. 34, the blue index (BI)-current density characteristics are shown in Fig. 35, and the electroluminescence spectrum is shown in Fig. 36.

[0501] Also, the values of voltage, current, current density, CIE chromaticity, current efficiency, external quantum efficiency, and blue index (BI) near 1000 cd / cm 2 are shown below. A spectro-radiometer (manufactured by Topcon Corporation, SR-UL1R) was used for the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, and the measurement was performed at room temperature.

[0502]

Table 8

[0503] From FIGS. 30 to 36 and Table 8, it was found that the light-emitting device 2 and the comparative light-emitting devices 2-1 to 2-3 are all light-emitting devices that exhibit good initial characteristics and are driven at equivalent luminous efficiencies and voltages. Further, it was found that the light-emitting device 2 and the comparative light-emitting devices 2-1 to 2-3 all have a peak wavelength of the electroluminescence spectrum of 464 nm and exhibit blue light emission derived from PtON-TBBI.

[0504] On the other hand, the normalized luminance time change characteristics of the light-emitting device 2 and the comparative light-emitting devices 2-1 to 2-3 at a current density of 10 mA / cm 2 are shown in FIG. 37.

[0505] From FIG. 37, it was found that the light-emitting device 2 according to one aspect of the present invention is a light-emitting device having a smaller change in normalized luminance over time and good reliability compared to the comparative light-emitting devices 2-1 to 2-3.

Example

[0506] In this example, the manufacturing methods and characteristics of the light-emitting device 3, which is a light-emitting device according to one aspect of the present invention, and the comparative light-emitting devices 3-1 to 3-3, which are comparative light-emitting devices, will be described in detail. The structural formulas of the main compounds used in the light-emitting device 3 and the comparative light-emitting devices 3-1 to 3-3 are shown below.

[0507]

Chemical formula

[0508] (Manufacturing method of the light-emitting device 3) First, 70 nm of indium tin oxide (ITSO) containing silicon oxide was laminated on a glass substrate by a sputtering method to form a first electrode 101 having a size of 2 mm × 2 mm. Note that the first electrode 101 functions as an anode.

[0509] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0510] Thereafter, the substrate was introduced into a vacuum evaporation apparatus whose internal pressure was reduced to about 1×10 -4 Pa, and in the heating chamber in the vacuum evaporation apparatus, after vacuum baking at 170 °C for 30 minutes, the substrate was allowed to cool for about 30 minutes.

[0511] Next, the substrate was fixed to a holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 101 was formed faced downward. On the inorganic insulating film and the first electrode 101, N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (ix) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-evaporated at a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) to form a hole injection layer 111.

[0512] On the hole injection layer 111, 30 nm of PCBBiF was evaporated to form a first hole transport layer, and subsequently, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) represented by the above structural formula (ii) was evaporated by 5 nm to form a second hole transport layer, thereby forming a hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0513] Subsequently, on the hole transport layer 112, 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole-1,2,3,4,5,6,7,8,1',2',3',4',5',6',7',8'-d 16 )(abbreviation: SiTrzCz2-d16) and 9-[3-(triphenylsilyl)phenyl]-3,9'-(bi-9H-carbazole-d 15)(Abbreviation: PSiCzCz-d15) and (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz5m4ppy-d 3 )) in a weight ratio of 0.45:0.45:0.10 (=SiTrzCz2-d16:PSiCzCz-d15:Pt(mmtBubOcz5m4ppy-d 3 )) were co-evaporated at 35 nm to form the light-emitting layer 113.

[0514] After that, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) represented by the above structural formula (vi) was evaporated to a thickness of 5 nm to form the first electron transport layer, and then 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (xi) was evaporated to a thickness of 20 nm to form the second electron transport layer, thereby forming the electron transport layer 114.

[0515] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was evaporated to a film thickness of 200 nm to form the second electrode 102.

[0516] Subsequently, in a glove box under a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate so as not to be exposed to the atmosphere (application of a UV-curable sealing material around the element, treatment of irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 °C for 1 hour under atmospheric pressure) to form the light-emitting device 3.

[0517] (Fabrication method of comparative light-emitting device 3-1) The comparative light-emitting device 3-1 was fabricated in the same manner as the light-emitting device 3, except that SiTrzCz2-d16 in the light-emitting device 3 was replaced with 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2) represented by the above structural formula (viii), and PSiCzCz-d15 was replaced with PSiCzCz.

[0518] (Fabrication method of comparative light-emitting device 3-2) The comparative light-emitting device 3-2 was fabricated in the same manner as the light-emitting device 3, except that PSiCzCz-d15 in the light-emitting device 3 was replaced with PSiCzCz.

[0519] (Fabrication method of comparative light-emitting device 3-3) The comparative light-emitting device 3-3 was fabricated in the same manner as the light-emitting device 3, except that SiTrzCz2-d16 in the light-emitting device 3 was replaced with SiTrzCz2.

[0520] The device structures of the light-emitting device 3 and the comparative light-emitting devices 3-1 to 3-3 are shown below.

[0521]

Table 9

[0522]

Table 10

[0523] Here, PSiCzCz and SiTrzCz2 are organic compounds in which the deuteriums of PSiCzCz-d15 and SiTrzCz2-d16 are hydrogen, respectively.

[0524] Note that on a quartz substrate, a thin film of SiTrzCz2-d16, a thin film of PSiCzCz-d15, and a mixed film co-evaporated with SiTrzCz2-d16 and PSiCzCz-d15 at a weight ratio of 1:1 so that the film thickness becomes 50 nm were deposited, and the PL spectra of the deposited films are shown in Fig. 62. For the measurement of the PL spectrum, a spectrofluorometer (FP-8600DS manufactured by JASCO Corporation) was used. As shown in Fig. 62, the PL spectrum of the mixed film is located at a longer wavelength than the PL spectra of the individual films, and it was found that SiTrzCz2-d16 and PSiCzCz-d15 form an exciplex.

[0525] The phosphorescence lifetimes of PSiCzCz, PSiCzCz-d15, SiTrzCz2, and SiTrzCz2-d16, and the magnification by which the phosphorescence lifetime changed due to deuteration are shown below. Also, the product of the respective magnifications was 1.40. Note that the excitation wavelength of PSiCzCz and PSiCzCz-d15 was 340 nm, and the measurement wavelength was 440 nm. The excitation wavelength of SiTrzCz2 and SiTrzCz2-d16 was 330 nm, and the measurement wavelength was 450 nm.

[0526]

Table 11

[0527] Also, the T 1 level of PSiCzCz-d15 is 2.97 eV, and the T 1 level of SiTrzCz2-d16 is 2.93 eV, and the difference is 0.04 eV.

[0528] Also, the 5% weight loss temperature of PSiCzCz-d15 at 10 Pa is 254 °C, and the 5% weight loss temperature of SiTrzCz2-d16 at 10 Pa is 298 °C, and the difference is 45 °C.

[0529] Note that the phosphorescence lifetime, T 1 level, and 5% weight loss temperature were calculated in the same manner as in Example 1.

[0530] In addition, the photoluminescence (PL) spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 shown in Fig. 62, and Pt(mmtBubOcz5m4ppy-d 3 ) of the polymethyl methacrylate (abbreviation: PMMA) dispersion film are shown superimposed in Fig. 64. As shown in Fig. 64, the PL spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 and the PL spectrum of the PMMA dispersion film of Pt(mmtBubOcz5m4ppy-d 3 ) have an overlap, and the difference in the maximum peak wavelength of each is 30 nm or less. The PMMA dispersion film of Pt(mmtBubOcz5m4ppy-d 3 ) uses deoxygenated dichloromethane as a solvent, and a solution in which Pt(mmtBubOcz5m4ppy-d 3 ) is dispersed at a concentration of 4.7 wt% with respect to PMMA is formed into a film on a quartz substrate by the drop-casting method, and dried at room temperature for 30 minutes under a nitrogen stream in a glove box. The emission spectrum of the obtained PMMA dispersion film of Pt(mmtBubOcz5m4ppy-d 3 ) was measured using an absolute PL quantum yield measurement device (Quantaurus-QY C11347-01 manufactured by Hamamatsu Photonics).

[0531] The luminance-current density characteristics of the light-emitting device 3 and the comparative light-emitting devices 3-1 to 3-3 are shown in Fig. 38, the current efficiency-current density characteristics are shown in Fig. 39, the luminance-voltage characteristics are shown in Fig. 40, the current density-voltage characteristics are shown in Fig. 41, the external quantum efficiency-luminance characteristics are shown in Fig. 42, the blue index (BI)-current density characteristics are shown in Fig. 43, and the electroluminescence spectrum is shown in Fig. 44.

[0532] Also, the values of voltage, current, current density, CIE chromaticity, current efficiency, external quantum efficiency, and blue index (BI) in the vicinity of 1000 cd / cm 2 are shown below. For the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, a spectro-radiometer (SR-UL1R manufactured by Topcon Corporation) was used and the measurement was performed at room temperature.

[0533]

Table 12

[0534] From FIGS. 38 to 44 and Table 12, it was found that the light-emitting device 3 and the comparative light-emitting devices 3-1 to 3-3 are all light-emitting devices that exhibit good initial characteristics and are driven at equivalent luminous efficiencies and voltages. Further, the light-emitting device 3 and the comparative light-emitting devices 3-1 to 3-3 all have a peak wavelength of the electroluminescence spectrum of 477 nm and exhibit blue light emission derived from Pt(mmtBubOcz5m4ppy-d 3 ).

[0535] On the other hand, the normalized luminance time change characteristics of the light-emitting device 3 and the comparative light-emitting devices 3-1 to 3-3 at a current density of 10 mA / cm 2 are shown in FIG. 45.

[0536] From FIG. 45, it was found that the light-emitting device 3 according to one aspect of the present invention is a light-emitting device having a smaller change in normalized luminance over time and good reliability compared to the comparative light-emitting devices 3-1 to 3-3.

Example

[0537] In this example, the manufacturing methods and characteristics of the light-emitting device 4, which is a light-emitting device according to one aspect of the present invention, and the comparative light-emitting devices 4-1 to 4-3, which are comparative light-emitting devices, will be described in detail. The structural formulas of the main compounds used in the light-emitting device 4 and the comparative light-emitting devices 4-1 to 4-3 are shown below.

[0538]

Chemical formula

[0539] (Manufacturing method of the light-emitting device 4) First, 70 nm of indium tin oxide (ITSO) containing silicon oxide was laminated on a glass substrate by sputtering to form a first electrode 101 with a size of 2 mm × 2 mm. Note that the first electrode 101 functions as an anode.

[0540] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0541] Thereafter, the substrate was introduced into a vacuum deposition apparatus whose internal pressure was reduced to about 1×10 -4 Pa. After performing vacuum baking at 170 °C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes.

[0542] Next, the substrate was fixed to a holder provided in the vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. On the inorganic insulating film and the first electrode 101, N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (ix) and an electron acceptor material (OCHD-003) containing fluorine with a molecular weight of 672 were co-evaporated at a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) to form a hole injection layer 111.

[0543] On the hole injection layer 111, 30 nm of PCBBiF was evaporated to form a first hole transport layer. Subsequently, 9-[3-(triphenylsilyl)phenyl]-3,9'-(bi-9H-carbazole-d 15 )(abbreviation: PSiCzCz-d15) was evaporated at 5 nm to form a second hole transport layer, thereby forming a hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0544] Subsequently, on the hole transport layer 112, 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole-1,2,3,4,5,6,7,8,1’,2’,3’,4’,5’,6’,7’,8’-d 16 )(abbreviation: SiTrzCz2-d16), PSiCzCz-d15, and (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz5m4ppy-d 3 )) represented by the above structural formula (x) are co-evaporated at a weight ratio of 0.45:0.45:0.10 (=SiTrzCz2-d16:PSiCzCz-d15:Pt(mmtBubOcz5m4ppy-d 3 )) to form a light-emitting layer 113 with a thickness of 35 nm.

[0545] After that, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) represented by the above structural formula (vi) is evaporated to a thickness of 5 nm to form a first electron transport layer. Subsequently, 2,2’-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (xi) is evaporated to a thickness of 20 nm to form a second electron transport layer, and an electron transport layer 114 is formed.

[0546] Subsequently, lithium fluoride (LiF) is evaporated to a thickness of 1 nm to form an electron injection layer 115. Then, aluminum (Al) is evaporated to a film thickness of 200 nm to form a second electrode 102.

[0547] Subsequently, in a glove box under a nitrogen atmosphere, an operation of sealing with a glass substrate was performed so that the light-emitting device was not exposed to the atmosphere (application of a UV-curable sealing material around the element, treatment of irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 °C for 1 hour under atmospheric pressure), and the light-emitting device 4 was formed.

[0548] (Method for manufacturing comparative light-emitting device 4-1) Comparative light-emitting device 4-1 was manufactured in the same manner as light-emitting device 4, except that SiTrzCz2-d16 in light-emitting device 4 was changed to 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2) represented by the above structural formula (viii), and PSiCzCz-d15 was changed to 9-[3-(triphenylsilyl)phenyl]-3,9’-bi-9H-carbazole (abbreviation: PSiCzCz) represented by the above structural formula (ii).

[0549] (Method for manufacturing comparative light-emitting device 4-2) Comparative light-emitting device 4-2 was manufactured in the same manner as light-emitting device 4, except that PSiCzCz-d15 in light-emitting device 4 was changed to PSiCzCz.

[0550] (Method for manufacturing comparative light-emitting device 4-3) Comparative light-emitting device 4-3 was manufactured in the same manner as light-emitting device 4, except that SiTrzCz2-d16 in light-emitting device 4 was changed to SiTrzCz2.

[0551] The device structures of light-emitting device 4 and comparative light-emitting devices 4-1 to 4-3 are shown below.

[0552]

Table 13

[0553]

Table 14

[0554] Here, PSiCzCz and SiTrzCz2 are organic compounds in which the deuteriums of PSiCzCz-d15 and SiTrzCz2-d16 are hydrogen, respectively.

[0555] Note that on a quartz substrate, a thin film of SiTrzCz2-d16, a thin film of PSiCzCz-d15, and a mixed film co-evaporated such that the weight ratio of SiTrzCz2-d16 and PSiCzCz-d15 is 1:1 with a film thickness of 50 nm were each deposited, and the PL spectra of the deposited films are shown in FIG. 62. For the measurement of the PL spectrum, a spectrofluorometer (FP-8600DS manufactured by JASCO Corporation) was used. As shown in FIG. 62, the PL spectrum of the mixed film is located at a longer wavelength than the PL spectra of the individual films, indicating that SiTrzCz2-d16 and PSiCzCz-d15 form an exciplex.

[0556] The phosphorescence lifetimes of PSiCzCz, PSiCzCz-d15, SiTrzCz2, and SiTrzCz2-d16, and the magnification by which the phosphorescence lifetime changed due to deuteration are shown below. The product of the respective magnifications was 1.40. Note that the excitation wavelength of PSiCzCz and PSiCzCz-d15 was 340 nm, and the measurement wavelength was 440 nm. The excitation wavelength of SiTrzCz2 and SiTrzCz2-d16 was 330 nm, and the measurement wavelength was 450 nm.

[0557]

Table 15

[0558] Also, the T 1 level of PSiCzCz-d15 is 2.97 eV, and the T 1 level of SiTrzCz2-d16 is 2.93 eV, and the difference therebetween is 0.04 eV.

[0559] The 5% weight loss temperature of PSiCzCz-d15 at 10 Pa was 254 °C, and the 5% weight loss temperature of SiTrzCz2-d16 at 10 Pa was 298 °C, and the difference was 45 °C.

[0560] The phosphorescence lifetime, T 1 The levels and 5% weight loss temperature were calculated in the same manner as in Example 1.

[0561] In addition, the photoluminescence (PL) spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16 shown in Fig. 62, and Pt(mmtBubOcz5m4ppy-d 3 ) of the polymethyl methacrylate (abbreviation: PMMA) dispersion film are superimposed in Fig. 64. As shown in Fig. 64, the PL spectrum of the exciplex formed by PSiCzCz-d15 and SiTrzCz2-d16, and Pt(mmtBubOcz5m4ppy-d 3 ) of the PMMA dispersion film have an overlap, and the difference in the maximum peak wavelength of each is 30 nm or less. The PMMA dispersion film of Pt(mmtBubOcz5m4ppy-d 3 ) uses deoxygenated dichloromethane as a solvent, and a solution in which Pt(mmtBubOcz5m4ppy-d 3 ) is dispersed at a concentration of 4.7 wt% is formed into a film on a quartz substrate by the drop-casting method, and dried at room temperature for 30 minutes under a nitrogen stream in a glove box. The emission spectrum of the obtained PMMA dispersion film of Pt(mmtBubOcz5m4ppy-d 3 ) was measured using an absolute PL quantum yield measurement device (Quantaurus-QY C11347-01 manufactured by Hamamatsu Photonics).

[0562] The luminance-current density characteristics of the light-emitting device 4 and the comparative light-emitting devices 4-1 to 4-3 are shown in Fig. 46, the current efficiency-current density characteristics are shown in Fig. 47, the luminance-voltage characteristics are shown in Fig. 48, the current density-voltage characteristics are shown in Fig. 49, the external quantum efficiency-luminance characteristics are shown in Fig. 50, the blue index (BI)-current density characteristics are shown in Fig. 51, and the electroluminescence spectrum is shown in Fig. 52.

[0563] Also, the values of voltage, current, current density, CIE chromaticity, current efficiency, external quantum efficiency, and blue index (BI) near 1000 cd / cm 2 are shown below. For the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, a spectro-radiometer (Topcon Corporation, SR-UL1R) was used and the measurement was performed at room temperature.

[0564]

Table 16

[0565] From FIGS. 46 to 52 and Table 16, it was found that the light-emitting device 4 and the comparative light-emitting devices 4-1 to 4-3 are all light-emitting devices that exhibit good initial characteristics driven at equivalent luminous efficiency and voltage. Also, the light-emitting device 4 and the comparative light-emitting devices 4-1 to 4-3 all have a peak wavelength of the electroluminescence spectrum of 477 nm and exhibit blue light emission derived from Pt(mmtBubOcz5m4ppy-d 3 ).

[0566] On the other hand, the normalized luminance time change characteristics of the light-emitting device 4 and the comparative light-emitting devices 4-1 to 4-3 at a current density of 10 mA / cm 2 are shown in FIG. 53.

[0567] From FIG. 53, it was found that the light-emitting device 4 according to one aspect of the present invention is a light-emitting device with a smaller time change in normalized luminance and better reliability compared to the comparative light-emitting devices 4-1 to 4-3.

Example

[0568] In this example, the manufacturing methods and characteristics of the light-emitting device 5, which is a light-emitting device according to one aspect of the present invention, and the comparative light-emitting devices 5-1 to 5-3, which are comparative light-emitting devices, will be described in detail. The structural formulas of the main compounds used in the light-emitting device 5 and the comparative light-emitting devices 5-1 to 5-3 are shown below.

[0569] [Chemical formula]

[0570] (Method for manufacturing the light-emitting device 5) First, on a glass substrate, 100 nm of silver (Ag) was deposited, followed by 10 nm of indium tin oxide (ITSO) containing silicon oxide by sputtering to form a first electrode 101 with a size of 2 mm × 2 mm. Note that the first electrode 101 functions as an anode.

[0571] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0572] Thereafter, the substrate was introduced into a vacuum evaporation apparatus whose internal pressure was reduced to about 1 × 10 -4 Pa, and in the heating chamber of the vacuum evaporation apparatus, vacuum baking was performed at 170 °C for 30 minutes, and then the substrate was allowed to cool for about 30 minutes.

[0573] Next, with the surface on which the first electrode 101 was formed facing downward, the substrate was fixed to a holder provided in the vacuum evaporation apparatus, and N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (ix) and an electron acceptor material (OCHD-003) containing fluorine with a molecular weight of 672 were co-evaporated at a weight ratio of 1:0.03 (= PCBBiF:OCHD-003) to form a hole injection layer 111.

[0574] On the hole injection layer 111, 140 nm of PCBBiF was deposited to form a hole transport layer 112.

[0575] Subsequently, on the hole transport layer 112, 8-(1,1’:4’,1’’-terphenyl-3-yl-2,4,5,6,2’,3’,5’,6’,2’’,3’’,4’’,5’’,6’’-d13)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d13) represented by the above structural formula (xii), 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9’-(phenyl-2,3,4,5,6-d5)-3,3’-bi-9H-carbazole-1,1’,2,2’,4,4’,5,5’,6,6’,7,7’,8,8’-d14 (abbreviation: βNCCP-d26) represented by the above structural formula (xiii), and tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d 3 ) 3 ) are co-evaporated at a weight ratio of 0.4:0.6:0.1 (= 8mpTP-4mDBtPBfpm-d13:βNCCP-d26:Ir(5m4dppy-d 3 ) 3 ) to a thickness of 40 nm to form the light-emitting layer 113.

[0576] Thereafter, 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzof[f,h]quinoxaline (abbreviation: 2mPCCzPDBq) represented by the above structural formula (xv) is evaporated to a thickness of 10 nm to form the first electron transport layer. Subsequently, 2,2’-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (xi) is evaporated to a thickness of 20 nm to form the second electron transport layer, thereby forming the electron transport layer 114.

[0577] Subsequently, lithium fluoride (LiF) was deposited to a thickness of 1 nm to form an electron injection layer 115. Thereafter, silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 1:0.1 (=Ag:Mg) to a thickness of 15 nm to form a second electrode 102. Finally, 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) represented by the above structural formula (xvi) was formed as a 70-nm-thick film on the second electrode 102 as a cap layer.

[0578] Subsequently, inside a glove box under a nitrogen atmosphere, a sealing operation was performed using a glass substrate so that the light-emitting device was not exposed to the atmosphere (application of a UV-curable sealing material around the element, treatment of irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80°C for 1 hour under atmospheric pressure), and a light-emitting device 5 was formed.

[0579] (Method for manufacturing comparative light-emitting device 5-1) Comparative light-emitting device 5-1 was manufactured in the same manner as light-emitting device 5, except that 8mpTP-4mDBtPBfpm-d13 in light-emitting device 5 was changed to 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm) represented by the above structural formula (xvii), and βNCCP-d26 was changed to 9-(2-naphthyl)-9’-phenyl-9H,9’H-3,3’-bicarbazole (abbreviation: βNCCP) represented by the above structural formula (xviii).

[0580] (Method for manufacturing comparative light-emitting device 5-2) Comparative light-emitting device 5-2 was manufactured in the same manner as light-emitting device 5, except that βNCCP-d26 in light-emitting device 5 was changed to βNCCP.

[0581] (Method for manufacturing comparative light-emitting device 5-3) Comparative light-emitting device 5-3 was manufactured in the same manner as light-emitting device 5, except that 8mpTP-4mDBtPBfpm-d13 in light-emitting device 5 was changed to 8mpTP-4mDBtPBfpm.

[0582] The device structures of the light-emitting device 5 and the comparative light-emitting devices 5-1 to 5-3 are shown below.

[0583]

Table 17

[0584]

Table 18

[0585] Here, 8mpTP-4mDBtPBfpm and βNCCP are organic compounds in which the deuteriums of 8mpTP-4mDBtPBfpm-d13 and βNCCP-d26 are hydrogen, respectively.

[0586] Note that a thin film of 8mpTP-4mDBtPBfpm-d13, a thin film of βNCCP-d26, and a mixed film co-evaporated so that the weight ratio of 8mpTP-4mDBtPBfpm-d13 and βNCCP-d26 is 1:1 with a film thickness of 50 nm on a quartz substrate were each deposited, and the PL spectra of the deposited films are shown in Fig. 65. For the measurement of the PL spectra, a spectrofluorometer (FP-8600DS manufactured by JASCO Corporation) was used. As shown in Fig. 65, the PL spectrum of the mixed film is located at a longer wavelength than the PL spectra of the individual films, and it was found that 8mpTP-4mDBtPBfpm-d13 and βNCCP-d26 form an exciplex.

[0587] The phosphorescence lifetimes of βNCCP, βNCCP-d26, 8mpTP-4mDBtPBfpm, and 8mpTP-4mDBtPBfpm-d13, and the magnification by which the phosphorescence lifetime changed due to deuteration are shown below. Also, the value obtained by multiplying the respective magnifications was 5.72. Note that the excitation wavelength of βNCCP and βNCCP-d26 was 330 nm, and the measurement wavelength was 515 nm. The excitation wavelength of 8mpTP-4mDBtPBfpm and 8mpTP-4mDBtPBfpm-d13 was 320 nm, and the measurement wavelength was 515 nm.

[0588]

Table 19

[0589] Also, the T 1 level of βNCCP-d26 is 2.56 eV, and the T 1 level of 8mpTP-4mDBtPBfpm-d13 is 2.55 eV, and the difference is 0.01 eV.

[0590] Also, the 5% weight loss temperature of βNCCP-d26 at 10 Pa is 257 °C, and the 5% weight loss temperature of 8mpTP-4mDBtPBfpm-d13 at 10 Pa is 312 °C, and the difference is 55 °C.

[0591] Note that the phosphorescence lifetime, T 1 level and 5% weight loss temperature were calculated in the same manner as in Example 1.

[0592] Also, as shown in Fig. 66, the PL spectrum of the exciplex formed by βNCCP-d26 and 8mpTP-4mDBtPBfpm-d13 3 ) 3 has an overlap with the PL spectrum of Ir(5m4dppy-d 3 ). 3 For the measurement of the PL spectrum of the dichloromethane solution of Ir(5m4dppy-d 3 ), a spectrofluorophotometer (FP-8600DS manufactured by JASCO Corporation) was used.

[0593] The luminance-current density characteristics of light-emitting device 5 and comparative light-emitting devices 5-1 to 5-3 are shown in Fig. 54, the luminance-voltage characteristics are shown in Fig. 55, the current efficiency-current density characteristics are shown in Fig. 56, the current density-voltage characteristics are shown in Fig. 57, the external quantum efficiency-current density characteristics are shown in Fig. 58, and the electroluminescence spectrum is shown in Fig. 59.

[0594] Also, 1000 cd / cm 2The values of the voltage, current, current density, CIE chromaticity, current efficiency, and external quantum efficiency in the vicinity are shown below. A spectroradiometer (Topcon Corporation, SR-UL1R) was used to measure the luminance, CIE chromaticity, and electroluminescence spectrum, and the measurements were made at room temperature.

[0595]

Table 20

[0596] From FIGS. 54 to 59 and Table 20, it was found that the light-emitting device 5 and the comparative light-emitting devices 5-1 to 5-3 are all light-emitting devices that exhibit good initial characteristics and are driven with equivalent luminous efficiency and voltage.

[0597] On the other hand, the normalized luminance time change characteristics of the light-emitting device 5 and the comparative light-emitting devices 5-1 to 5-3 at a current density of 50 mA / cm 2 are shown in FIG. 60.

[0598] From FIG. 60, it was found that the light-emitting device 5 of one aspect of the present invention is a light-emitting device having a smaller time change in normalized luminance and good reliability compared to the comparative light-emitting devices 5-1 to 5-3.

Example

[0599] In this example, the manufacturing method and characteristics of the light-emitting device 6, which is a light-emitting device of one aspect of the present invention, and the comparative light-emitting device 6, which is a comparative light-emitting device, will be described in detail. The structural formulas of the main compounds used in the light-emitting device 6 and the comparative light-emitting device 6 are shown below.

[0600]

Chemical formula

[0601] (Manufacturing method of the light-emitting device 6) First, indium tin oxide (ITSO) containing silicon oxide was laminated on a glass substrate to a thickness of 110 nm by sputtering, and a first electrode 101 with a size of 2 mm × 2 mm was formed. Note that the fir...

Claims

1. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; the first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; A light-emitting device, wherein a difference between the lowest triplet excitation level of the first organic compound and the lowest triplet excitation level of the second organic compound is 0.20 eV or less.

2. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; the first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; the first organic compound and the second organic compound are a combination that forms an exciplex, A light-emitting device in which the emission spectrum of the exciplex overlaps with the emission spectrum of a substance capable of converting triplet excitation energy into light emission.

3. In claim 2, A light-emitting device, wherein the difference between the maximum peak wavelength of the emission spectrum of the exciplex and the maximum peak wavelength of the emission spectrum of the substance capable of converting triplet excitation energy into light emission is 30 nm or less.

4. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; the first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; The phosphorescence lifetime or delayed fluorescence lifetime of the first organic compound at 77K is 1.20 times or more of the phosphorescence lifetime or delayed fluorescence lifetime of a third organic compound at 77K in which the deuterium of the first organic compound is hydrogen; A light-emitting device in which the phosphorescence lifetime or delayed fluorescence lifetime of the second organic compound at 77K is 1.05 times or more the phosphorescence lifetime or delayed fluorescence lifetime of a fourth organic compound at 77K in which the deuterium in the second organic compound is hydrogen.

5. In claim 4, A light-emitting device, wherein the peak wavelength of an emission spectrum of light emitted by the substance capable of converting triplet excitation energy into light emission is 450 nm or more and less than 500 nm.

6. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; the first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; The phosphorescence lifetime or delayed fluorescence lifetime of the first organic compound at 77K is 1.50 times or more of the phosphorescence lifetime or delayed fluorescence lifetime of a third organic compound at 77K in which the deuterium of the first organic compound is hydrogen; A light-emitting device, in which the phosphorescence lifetime or delayed fluorescence lifetime of the second organic compound at 77K is 3.00 times or more the phosphorescence lifetime or delayed fluorescence lifetime of a fourth organic compound at 77K in which the deuterium in the second organic compound is hydrogen.

7. In claim 6, A light-emitting device, wherein the substance capable of converting triplet excitation energy into light emits light having an emission spectrum with a peak wavelength of 500 nm or more and 600 nm or less.

8. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; the first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; The phosphorescence lifetime or delayed fluorescence lifetime of the first organic compound at 77K is X times that of a third organic compound in which the deuterium of the first organic compound is hydrogen, and the phosphorescence lifetime or delayed fluorescence lifetime of the second organic compound at 77K is Y times that of a fourth organic compound in which the deuterium of the second organic compound is hydrogen, A light emitting device in which the product of X and Y is 1.26 or greater.

9. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; The peak wavelength of the light emitted by the substance capable of converting triplet excitation energy into luminescence is 500 nm or more and 600 nm or less. the first organic compound has a π-electron deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; The phosphorescence lifetime or delayed fluorescence lifetime of the first organic compound at 77K is X times that of a third organic compound in which the deuterium of the first organic compound is hydrogen, and the phosphorescence lifetime or delayed fluorescence lifetime of the second organic compound at 77K is Y times that of a fourth organic compound in which the deuterium of the second organic compound is hydrogen, A light emitting device in which the product of X and Y is 4.50 or greater.

10. A first electrode, a second electrode, and a light-emitting layer, the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer includes a first organic compound, a second organic compound, and a substance capable of converting triplet excitation energy into light emission; the first organic compound has a π-electron-deficient heteroaromatic ring, the second organic compound has a π-electron rich heteroaromatic ring or an aromatic amine skeleton, the first organic compound and the second organic compound contain deuterium; A light-emitting device, wherein a difference between a 5% weight loss temperature at 10 Pa of the first organic compound and a 5% weight loss temperature at 10 Pa of the second organic compound is 60° C. or less.

11. In any one of claims 1 to 8, The light-emitting device, wherein the material capable of converting triplet excitation energy into light emission is a phosphorescent material.

12. In any one of claims 1, 4 to 9, A light-emitting device in which the first organic compound and the second organic compound form an exciplex.

13. In any one of claims 1 to 8, the first organic compound is an organic compound having a diazine skeleton or a triazine skeleton, A light-emitting device, wherein the second organic compound is an organic compound having a bicarbazole skeleton.

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