Light-emitting device

Abstract

To provide a novel light-emitting device, a light-emitting device with excellent luminous efficiency, a light-emitting device with an excellent life, or a light-emitting device with low driving voltage.SOLUTION: In a light-emitting device, an EL layer includes a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer in this order from an anode side. The first layer contains a first organic compound and a second organic compound. The fourth layer contains a seventh organic compound. The first organic compound exhibits the electron accepting property with respect to the second organic compound. The second organic compound has a HOMO Level of -5.7 eV or more and -5.4 eV or less. When the square root the electric field intensity [V / cm] of the seventh organic compound is 600, the electronic mobility is 1×10-7 cm2 / Vs or more and 5×10-5 cm2 / Vs or less and the HOMO level is -6.0 eV or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Electroluminescence (EL) using organic compounds The practical application of light-emitting devices (organic electroluminescence (EL) elements) that utilize these luminescence elements is progressing. The basic structure of the device is a layer of organic compounds (EL layer) containing light-emitting materials sandwiched between a pair of electrodes. By applying a voltage to this element, carriers are injected and the recombination of the carriers occurs. By utilizing the energy, light can be emitted from the light-emitting material.

[0003] Since such light-emitting devices are self-emitting, when they are used as pixels in a display, Compared to flat panel displays, it has the advantage of being more visible and not requiring a backlight. A display using such a light-emitting device is suitable as a display element. Another major advantage is that it can be manufactured to be thin and lightweight. Another advantage is that it has an extremely fast response time. It is one of the signs.

[0004] In addition, these light-emitting devices can form light-emitting layers continuously in two dimensions. This is the same as point light sources such as incandescent light bulbs and LEDs, This is a feature that is difficult to obtain with linear light sources such as fluorescent lamps, so it is considered to be a surface light source that can be applied to lighting, etc. It is also highly useful as a tool.

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

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

[0007] The properties of light-emitting devices have improved remarkably, but many other properties, including efficiency and durability, remain unclear. However, it must be said that the current technology is still insufficient to meet the high demands on the [Prior art documents] [Patent documents]

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

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

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

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

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

[0013] Alternatively, another aspect of the present invention is a semiconductor device comprising an anode, a cathode, and a semiconductor device disposed between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer is composed of a first layer and a second layer in this order from the anode side. The first layer is in contact with the anode, and the third layer is in contact with the light-emitting layer. the first layer has a first organic compound and a second organic compound, and the second layer has a the third layer comprises a fourth organic compound, and the light-emitting layer comprises a fifth organic compound. the fourth layer has a seventh organic compound, and the sixth organic compound; The first organic compound is an organic compound that exhibits electron accepting properties to the second organic compound, The fifth organic compound is a luminescent center substance, and the HOMO level of the second organic compound is -5. 7 eV or more and -5.4 eV or less, and the seventh organic compound is When the square root is 600, the electron mobility is 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, and the light emission obtained when a constant current is applied to the light-emitting device The deterioration curve, which is represented by a change in luminance of the light emitting device, has a maximum value.

[0014] Alternatively, another aspect of the present invention is a semiconductor device comprising an anode, a cathode, and a semiconductor device disposed between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer is composed of a first layer and a second layer in this order from the anode side. The first layer is in contact with the anode, and the third layer is in contact with the light-emitting layer. the fourth layer is in contact with the light-emitting layer, and the first layer comprises a first organic compound and a second organic compound. the second layer having a second organic compound, the second layer having a third organic compound, and the third layer having a third organic compound. the light-emitting layer comprises a fifth organic compound and a sixth organic compound; The fourth layer has a seventh organic compound, and the first organic compound is a seventh organic compound. the fifth organic compound is a luminescent center material, and The HOMO level of the second organic compound is -5.7 eV or more and -5.4 eV or less, The organic compound No. 7 exhibits electron transfer when the square root of the electric field strength [V / cm] is 600. Degree is 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, The HOMO level of the organic compound is -6.0 eV or higher, and a constant current is applied to the light-emitting device. The degradation curve, which is expressed by the change in luminance of light emitted when the device is depleted, has a maximum value. do.

[0015] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and has a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. The first organic compound has an electron accepting property for the second organic compound. the fifth organic compound is a luminescent center substance, and H of the second organic compound is The OMO level is -5.7 eV or more and -5.4 eV or less, and the third organic compound and the The difference in HOMO level between the organic compound 2 and the organic compound 3 is 0.2 eV or less, and The HOMO level of the seventh organic compound is equal to or deeper than the HOMO level of the second organic compound. The organic compound has an electron mobility of 1 when the square root of the electric field strength [V / cm] is 600. ×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, and the seventh organic compound The HOMO level of the material is -6.0 eV or higher, and when a constant current is applied to the light-emitting device, The degradation curve, which is expressed by the change in luminance of the light emitted from the light-emitting device, has a maximum value.

[0016] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and includes a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. The first organic compound has an electron accepting property for the second organic compound. The second organic compound has a first hole transporting skeleton, and the third organic compound has a second hole transporting skeleton. The compound has a second hole-transporting skeleton, and the fourth organic compound has a third hole-transporting skeleton. the fifth organic compound is a luminescent center substance, and the HOM of the second organic compound is The O level is −5.7 eV or more and −5.4 eV or less, and the first hole transporting skeleton, The second hole transport skeleton and the third hole transport skeleton each independently comprise a carbazole skeleton. The compound may have any one of a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. The seventh organic compound has a square root of an electric field strength [V / cm] of 600. The electron mobility in -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, the seventh organic compound has a HOMO level of −6.0 eV or more; The degradation curve, which represents the change in luminance of light emitted when a constant current is applied, has a maximum value. It is a device.

[0017] Alternatively, another aspect of the present invention is a semiconductor device comprising an anode, a cathode, and a semiconductor device disposed between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer is composed of a first layer and a second layer in this order from the anode side. The first layer is in contact with the anode, and the third layer is in contact with the light-emitting layer. the fourth layer is in contact with the light-emitting layer, and the first layer comprises a first organic compound and a second organic compound. the second layer having a second organic compound, the second layer having a third organic compound, and the third layer having a third organic compound. the light-emitting layer comprises a fifth organic compound and a sixth organic compound; The fourth layer has a seventh organic compound and an eighth substance, and the first organic compound is a second organic compound. The fifth organic compound is an organic compound that exhibits electron accepting properties to the organic compound of the above-mentioned third organic compound. The HOMO level of the second organic compound is -5.7 eV or more and -5.4 eV or less. the seventh organic compound is an organic compound having an anthracene skeleton, and the eighth The material is an organic complex of an alkali metal or an alkaline earth metal, and the light-emitting device The degradation curve, which represents the change in luminance of light emitted when a constant current is applied, has a maximum value. It is an optical device.

[0018] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and has a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. an eighth substance, the first organic compound being capable of accepting an electron into the second organic compound; the fifth organic compound is a luminescence center substance; and the second organic compound is an organic compound exhibiting a luminescence property. The HOMO level of the organic compound is -5.7 eV or more and -5.4 eV or less, and the third organic compound a difference in HOMO level between the third organic compound and the second organic compound is 0.2 eV or less; the HOMO level of the organic compound is equal to or deeper than the HOMO level of the second organic compound; The seventh organic compound is an organic compound having an anthracene skeleton, and the eighth material is is an organic complex of an alkali metal or an alkaline earth metal, The degradation curve, which represents the change in luminance of light emitted when a current is passed through it, has a maximum value. It is a chair.

[0019] Another aspect of the present invention is a light-emitting diode (ELD) device comprising an anode, a cathode, and an EL layer located between the anode and the cathode. The EL layer includes, in order from the anode side, a first layer, a second layer, a third layer, and a light-emitting layer, a fourth layer, the first layer being in contact with the anode, the fourth layer being the light-emitting layer the first layer has a first organic compound and a second organic compound, the third layer comprises a third organic compound, the third layer comprises a fourth organic compound, and the light-emitting The fourth layer has a fifth organic compound and a sixth organic compound, and the fourth layer has a seventh organic compound. and an eighth substance, wherein the first organic compound exhibits electron accepting properties for the second organic compound. The second organic compound has a first hole transporting skeleton, and the third organic compound has a second hole transporting skeleton. The organic compound has a second hole transporting skeleton, and the fourth organic compound has a third hole transporting skeleton. the fifth organic compound is a luminescent center substance, and H of the second organic compound is The OMO level is -5.7 eV or more and -5.4 eV or less, and the first hole transport skeleton, The second hole transport skeleton and the third hole transport skeleton are each independently a carbazole. skeleton, dibenzofuran skeleton, dibenzothiophene skeleton, or anthracene skeleton the seventh organic compound is an organic compound having an anthracene skeleton, The eighth substance is an organic complex of an alkali metal or an alkaline earth metal, and the light-emitting device The degradation curve, which represents the change in luminance of light emitted when a constant current is passed through the It is a light-emitting device.

[0020] Another aspect of the present invention is a method for manufacturing a semiconductor device having a deterioration curve that exceeds 100% in the above configuration. It is a light-emitting device.

[0021] Another aspect of the present invention is a light-emitting diode (ELD) comprising an anode, a cathode, and an EL layer located between the anode and the cathode. In the light-emitting device having the above structure, the EL layer is composed of a first layer, a second layer, and The first layer is in contact with the anode, and the second layer is in contact with the cathode. The fourth layer is in contact with the light-emitting layer, and the first layer is a layer including a first organic compound and a second organic compound. the first layer having a third organic compound, and the third layer having a fourth organic compound. the light-emitting layer comprises a fifth organic compound and a sixth organic compound, and the fourth organic compound The layer has a seventh organic compound, and the first organic compound accepts electrons from the second organic compound. the fifth organic compound is a luminescent center substance; and the second organic compound is an organic compound exhibiting a luminescence property. The HOMO level of the organic compound is -5.7 eV or more and -5.4 eV or less, and the seventh organic The compound has an electron mobility of 1× when the square root of the electric field strength [V / cm] is 600. 10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, and the seventh organic compound The HOMO level of the light-emitting device is -6.0 eV or higher.

[0022] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and includes a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. The first organic compound has an electron accepting property for the second organic compound. the fifth organic compound is a luminescent center substance, and H of the second organic compound is The OMO level is -5.7 eV or more and -5.4 eV or less, and the third organic compound and the The difference in HOMO level between the organic compound 2 and the organic compound 3 is 0.2 eV or less, and The HOMO level of the seventh organic compound is equal to or deeper than the HOMO level of the second organic compound. The organic compound has an electron mobility of 1 when the square root of the electric field strength [V / cm] is 600. ×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, and the seventh organic compound The HOMO level of the material is -6.0 eV or higher.

[0023] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and has a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. The first organic compound has an electron accepting property for the second organic compound. The second organic compound has a first hole transporting skeleton, and the third organic compound has a second hole transporting skeleton. The compound has a second hole-transporting skeleton, and the fourth organic compound has a third hole-transporting skeleton. the fifth organic compound is a luminescent center substance, and the HOM of the second organic compound is The O level is −5.7 eV or more and −5.4 eV or less, and the first hole transporting skeleton, The second hole transport skeleton and the third hole transport skeleton each independently comprise a carbazole skeleton. The compound may have any one of a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. The seventh organic compound has a square root of an electric field strength [V / cm] of 600. The electron mobility in -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less, The seventh organic compound has a HOMO level of −6.0 eV or higher in the light-emitting device.

[0024] Alternatively, another aspect of the present invention is a semiconductor device comprising an anode, a cathode, and a semiconductor device disposed between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer is composed of a first layer and a second layer in this order from the anode side. The first layer is in contact with the anode, and the third layer is in contact with the light-emitting layer. the fourth layer is in contact with the light-emitting layer, and the first layer comprises a first organic compound and a second organic compound. the second layer having a second organic compound, the second layer having a third organic compound, and the third layer having a third organic compound. the light-emitting layer comprises a fifth organic compound and a sixth organic compound; The fourth layer has a seventh organic compound and an eighth substance, and the first organic compound is a second organic compound. The fifth organic compound is an organic compound that exhibits electron accepting properties to the organic compound of the above-mentioned third organic compound. The HOMO level of the second organic compound is -5.7 eV or more and -5.4 eV or less. the seventh organic compound is an organic compound having an anthracene skeleton, and the eighth The material is a light-emitting device that is an organic complex of an alkali metal or alkaline earth metal.

[0025] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and includes a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. an eighth substance, the first organic compound being capable of accepting an electron into the second organic compound; the fifth organic compound is a luminescence center substance; and the second organic compound is an organic compound exhibiting a luminescence property. The HOMO level of the organic compound is -5.7 eV or more and -5.4 eV or less, and the third organic compound a difference in HOMO level between the third organic compound and the second organic compound is 0.2 eV or less; the HOMO level of the organic compound is equal to or deeper than the HOMO level of the second organic compound; The seventh organic compound is an organic compound having an anthracene skeleton, and the eighth material is is a light emitting device that is an organic complex of an alkali metal or alkaline earth metal.

[0026] Alternatively, another aspect of the present invention is a liquid crystal display comprising an anode, a cathode, and an E The EL layer is made up of a first layer, a second layer, a third layer, and an emitting layer, in this order from the anode side. The first layer is in contact with the anode, and the fourth layer is a front layer. the first layer is in contact with the light-emitting layer and includes a first organic compound and a second organic compound; the second layer comprises a third organic compound, and the third layer comprises a fourth organic compound; The light-emitting layer includes a fifth organic compound and a sixth organic compound, and the fourth layer includes a seventh organic compound. an eighth substance, the first organic compound being capable of accepting an electron into the second organic compound; the second organic compound has a first hole transport skeleton and The third organic compound has a second hole transport skeleton, and the fourth organic compound has a third The fifth organic compound is a luminescent center substance, and the second organic compound has a hole transporting skeleton. The HOMO level of the compound is −5.7 eV or more and −5.4 eV or less, and the first hole transporting The skeleton, the second hole transport skeleton and the third hole transport skeleton each independently comprise a carbene group. The benzol skeleton, dibenzofuran skeleton, dibenzothiophene skeleton and anthracene skeleton and the seventh organic compound is an organic compound having an anthracene skeleton. The eighth substance is a luminescent device which is an organic complex of an alkali metal or an alkaline earth metal. It is a chair.

[0027] Alternatively, in the above-mentioned structure, another embodiment of the present invention is a compound in which the seventh organic compound is an anthraquinone. The light-emitting device is an organic compound having a cenene skeleton and a heterocyclic skeleton.

[0028] Alternatively, another embodiment of the present invention is a semiconductor device having the above-mentioned structure, wherein the electron mobility of the seventh organic compound is is a light-emitting device having an electron mobility smaller than that of the sixth organic compound.

[0029] Alternatively, in the above structure, another embodiment of the present invention is a HOMO approximation of the fourth organic compound. a difference between the HOMO level of the third organic compound and the HOMO level of the first organic compound is 0.2 eV or less; It is.

[0030] Alternatively, in the above structure, another embodiment of the present invention is a HOMO approximation of the fourth organic compound. The light-emitting device has a HOMO level deeper than the HOMO level of the third organic compound.

[0031] Alternatively, another embodiment of the present invention is a photosensitive resin composition according to the above structure, wherein the second organic compound is a dibenzo The light-emitting device is an organic compound having a furan skeleton.

[0032] Alternatively, another embodiment of the present invention is a method for manufacturing a semiconductor device comprising the steps of: Organic compounds are the same material as light-emitting devices.

[0033] Alternatively, in the above-mentioned configuration, the fifth organic compound is a blue fluorescent material. It is a light-emitting device that is a material.

[0034] Alternatively, another aspect of the present invention is a device in which a sensor, an operation button, a speaker, or Or, Mike, It is an electronic device having the following:

[0035] Another embodiment of the present invention is a semiconductor device having the above structure, further comprising: It is a light emitting device having the above structure.

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

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

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

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

[0040] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have to have all of these effects. Effects other than these may also be included. The above is self-evident from the description, drawings, claims, etc. Other effects can be extracted from the claims and other descriptions. [Brief description of the drawings]

[0041] [Figure 1] Schematic diagram of a light-emitting device. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 1 is a conceptual diagram of an active matrix light-emitting device. [Diagram 5] FIG. 1 is a conceptual diagram of an active matrix light-emitting device. [Figure 6] FIG. 1 is a conceptual diagram of an active matrix light-emitting device. [Figure 7] FIG. 1 is a conceptual diagram of a passive matrix light-emitting device. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] A diagram showing an electronic device. [Figure 11] FIG. [Figure 12] FIG. [Figure 13] 1 is a diagram illustrating an in-vehicle display device and a lighting device. [Figure 14] A diagram showing an electronic device. [Figure 15] FIG. [Figure 16] Luminance-current density characteristics of light-emitting device 1. [Figure 17] Current efficiency-luminance characteristics of light-emitting device 1. [Figure 18] Luminance-voltage characteristics of light-emitting device 1. [Figure 19] Current-voltage characteristics of light-emitting device 1. [Figure 20] External quantum efficiency-luminance characteristics of light-emitting device 1. [Figure 21] Emission spectrum of light-emitting device 1. [Figure 22] Normalized luminance vs. time change characteristics of light-emitting device 1. [Figure 23] Luminance-current density characteristics of light-emitting device 2. [Figure 24] Current efficiency-luminance characteristics of light-emitting device 2. [Diagram 25] Luminance-voltage characteristics of light-emitting device 2. [Figure 26] Current-voltage characteristics of light-emitting device 2. [Figure 27] External quantum efficiency-luminance characteristics of light-emitting device 2. [Figure 28] Emission spectrum of light-emitting device 2. [Figure 29] Normalized luminance-time change characteristics of light-emitting device 2. [Diagram 30] Luminance-current density characteristics of light-emitting device 3. [Diagram 31] Current efficiency-luminance characteristics of light-emitting device 3. [Diagram 32] Luminance-voltage characteristics of light-emitting device 3. [Diagram 33] Current-voltage characteristics of light-emitting device 3. [Diagram 34] External quantum efficiency-luminance characteristics of light-emitting device 3. [Diagram 35] Emission spectrum of light-emitting device 3. [Diagram 36] Normalized luminance-time change characteristics of light-emitting device 3. [Figure 37] FIG. 1 is a diagram showing the structure of an electron-only element. [Figure 38] Current density-voltage characteristics of electron-only elements. [Figure 39]Frequency characteristics of the calculated capacitance C of ZADN:Liq (1:1) at DC voltage of 7.0V. [Diagram 40] Frequency characteristics of -ΔB of ZADN:Liq(1:1) at DC voltage of 7.0V. [Diagram 41] Electric field strength dependence of electron mobility in various organic compounds. [Diagram 42] Luminance-current density characteristics of light-emitting device 4. [Diagram 43] Current efficiency-luminance characteristics of light-emitting device 4. [Diagram 44] Luminance-voltage characteristics of light-emitting device 4. [Diagram 45] Current-voltage characteristics of light-emitting device 4. [Diagram 46] External quantum efficiency-luminance characteristics of light-emitting device 4. [Figure 47] Emission spectrum of light-emitting device 4. [Figure 48] Normalized luminance-time change characteristics of light-emitting device 4. [Figure 49] Luminance-current density characteristics of light-emitting device 5. [Figure 50] Current efficiency-luminance characteristics of light-emitting device 5. [Figure 51] Luminance-voltage characteristics of light-emitting device 5. [Figure 52] Current-voltage characteristics of light-emitting device 5. [Figure 53] External quantum efficiency-luminance characteristics of light-emitting device 5. [Figure 54] Emission spectrum of light-emitting device 5. [Figure 55] Normalized luminance-time change characteristics of light-emitting device 5. [Figure 56] Luminance-current density characteristics of light-emitting device 6. [Figure 57] Current efficiency-luminance characteristics of light-emitting device 6. [Figure 58] Luminance-voltage characteristics of light-emitting device 6. [Figure 59] Current-voltage characteristics of light-emitting device 6. [Figure 60] External quantum efficiency-luminance characteristics of light-emitting device 6. [Figure 61] Emission spectrum of light-emitting device 6. [Figure 62] Normalized luminance-time change characteristics of light-emitting device 6. [Figure 63] Luminance-current density characteristics of light-emitting device 7. [Figure 64] Current efficiency-luminance characteristics of light-emitting device 7. [Figure 65] Luminance-voltage characteristics of light-emitting device 7. [Figure 66] Current-voltage characteristics of light-emitting device 7. [Figure 67] External quantum efficiency-luminance characteristics of light-emitting device 7. [Figure 68] Emission spectrum of light-emitting device 7. [Figure 69] Normalized luminance-time change characteristics of light-emitting device 7. [Figure 70] Luminance-current density characteristics of light-emitting device 8 and light-emitting device 9. [Figure 71] Current efficiency-luminance characteristics of light-emitting device 8 and light-emitting device 9. [Figure 72] Luminance-voltage characteristics of light-emitting device 8 and light-emitting device 9. [Figure 73] Current-voltage characteristics of light-emitting device 8 and light-emitting device 9. [Figure 74] External quantum efficiency-luminance characteristics of light-emitting device 8 and light-emitting device 9. [Figure 75] 4 shows the emission spectra of light-emitting device 8 and light-emitting device 9. [Figure 76] Normalized luminance-time change characteristics of light-emitting device 8 and light-emitting device 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

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

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

[0045] The hole injection layer 111 includes a first organic compound and a second organic compound. The compound is a substance that exhibits electron accepting properties toward the second organic compound. The substance has a relatively deep HOMO level between -5.7 eV and -5.4 eV. The second organic compound has a relatively deep HOMO level. This facilitates the injection of holes into the hole transport layer 112 .

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

[0047] The second organic compound is preferably an organic compound having a hole transporting property, and is preferably a carbazole. The structure is selected from the group consisting of the benzoyl skeleton, the dibenzofuran skeleton, the dibenzothiophene skeleton, and the anthracene skeleton. In particular, it is preferable that the aryl group has a dibenzofuran ring or a dibenzothiophene ring. Aromatic amines having a substituent containing a naphthalene ring, aromatic monoamines having a naphthalene ring, or 9- Aromatic monoamines in which the fluorenyl group is attached to the amine nitrogen through an arylene group are preferred. It is preferable that the second organic compound has an N,N-bis(4-biphenyl)amino group. It is more preferable to use a material having such a property since it is possible to fabricate a light-emitting device having a long life. Specific examples of the second organic compound include N-(4-biphenyl)-6, N-Diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfA BP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2- d]Furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo [b]Naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1 ,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-bifuran phenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf( 8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4 -amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran -4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenyl ThBA1BP, 4-(2-naphthyl)-4',4''-diphenyl Triphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]- 4',4''-Diphenyltriphenylamine (abbreviation: BBAβNBi), 4-(2;1 '-Binaphthyl-6-yl)-4',4''-diphenyltriphenylamine (abbreviation: B BAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl ) Triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4' '-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB- 03), 4-(6;2'-binaphthyl-2-yl)-4',4''-diphenyltriphenyl Nylamine (abbreviation: BBA(βN2)B), 4-(2;2'-binaphthyl-7-yl)- 4',4''-Diphenyltriphenylamine (abbreviation: BBA(βN2)B-03), 4 -(1;2'-binaphthyl-4-yl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNαNB), 4-(1;2'-binaphthyl-5-yl)-4',4'' -Diphenyltriphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl 4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TP BiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl] -4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-bi phenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenyl TPBiAβNBi, 4-(1-naphthyl)-4'-phenyltriphenylamine phenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenyl Amine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazo (yl-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP ), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris( 1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4 '-(Carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4 ''-Phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl N-[4-(1-naphthyl)phenyl]-9H-carbazol-3-yl PCBNBSF , N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H- Fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl BB ASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl- 9H-Fluoren-2-yl)-9,9'-spirobi[9H-fluoren]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H- Fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-( 1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl nyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9 -phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), mB PAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl 4-phenyl-4'-(9-phenyl)triphenylamine (abbreviation: BPAFLBi) (9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)trimethylsilyl Phenylamine (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 -9,9'-spirobi[9H-fluorenyl-9H-carbazol-3-yl]phenyl N-(1,1'-biphenyl-4-yl)-2-amine (abbreviation: PCBASF), 9,9-Dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] Examples include [9H-fluorene-2-amine (abbreviation: PCBBiF), etc.

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

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

[0050] The third organic compound and the fourth organic compound are organic compounds having a hole transporting property. It is preferable that the third organic compound and the fourth organic compound are used as the second organic compound. Any organic compound capable of being reacted with the catalyst can be used in the same manner.

[0051] The HOMO level of the second organic compound and the HOMO level of the third organic compound are The HOMO level of the compound is deeper than that of the other, and the difference between the two materials is selected to be 0.2 eV or less. It is preferable that the second organic compound and the third organic compound are the same substance. Even more preferred.

[0052] In addition, the HOMO level of the third organic compound and the HOMO level of the fourth organic compound are It is preferable that the HOMO level of the organic compound is deeper than that of the compound of the present invention. It is advisable to select the materials so that the second organic compound, the third organic compound, and the fourth organic compound are H. The above-mentioned relationship of the OMO levels allows holes to be smoothly injected into each layer, It is possible to prevent an increase in driving voltage and a state in which there are insufficient holes in the light-emitting layer.

[0053] Each of the second to fourth organic compounds preferably has a hole-transporting skeleton. As the hole transporting skeleton, the HOMO level of these organic compounds is preferably too shallow. Carbazole skeleton, dibenzofuran skeleton, dibenzothiophene skeleton and anthracene skeleton In addition, the hole transporting skeleton is preferably a material of adjacent layers (for example, the second (a) an organic compound and a third organic compound, or a third organic compound and a fourth organic compound) In particular, the hole transport skeleton is preferably a is preferably a dibenzofuran skeleton.

[0054] In addition, materials contained in adjacent layers (e.g., a second organic compound and a third organic compound or a If the organic compound (3) and the organic compound (4) are the same material, the hole injection becomes smoother. In particular, the second organic compound and the third organic compound are made of the same material. The configuration is preferred.

[0055] The light-emitting layer 113 contains a fifth organic compound and a sixth organic compound. The fifth organic compound is The sixth organic compound is a host material for dispersing the fifth organic compound. It is a fee.

[0056] The luminescent center material may be a fluorescent material, a phosphorescent material, or a thermally activated delayed fluorescence material. The material may be a material exhibiting TADF or other light-emitting materials. The light-emitting device of the present invention may be made up of a single layer or a plurality of layers each containing a different light-emitting material. In one embodiment, the light-emitting layer 113 is a layer that exhibits fluorescent emission, in particular, a layer that exhibits blue fluorescent emission. This can be suitably applied depending on the circumstances.

[0057] Examples of materials that can be used as the fluorescent substance in the light-emitting layer 113 include: 5,6-Bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine PAP2BPy, 5,6-bis[4'-(10-phenyl-9-anthracene N, N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl] )phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-biphenyl Bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene 9-yl)phenyl]-pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPr n), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'- Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carba 4'-(10-phenyl-9-anthryl)triphenylamine ( Abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl N,9-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), Phenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol Perylene, 2,5,8,11-tetra(tert -butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4' -(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCB APA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4 ,1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine ](abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl- 2-Anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA ), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N' -Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N' ,N',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]chloride Cen-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9 ,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3 -amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2- yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation Name: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N', N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9, 10-Bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'- Triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-Bi S(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl) Phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N, N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), Coumarin 5 45T, N,N'-diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12 -Bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl 2-(4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), Methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoline Lysin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation Name: 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}propanediyl tolyl (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7, 7-Tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolin 4H-pyran-4-ylidene)propanedinitrile (abbreviation) :DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethene {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'- (Pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2- d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[ N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[ 2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV) -02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino] Naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf (IV)-02) are particularly notable. PAPrn, 1,6BnfAPrn-03, and other pyrene diamine compounds Synthetic aromatic diamine compounds have high hole trapping properties, and are excellent in luminous efficiency and reliability. In addition, other fluorescent materials can also be used.

[0058] In the case where a phosphorescent material is used as the luminescent center material in the luminescent layer 113, it is possible to use Possible materials include, for example, tris{2-[5-(2-methylphenyl)-4-(2, 6-Dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl {Ir(mpptz-dmp)3}iridium(III) (5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(I II) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-iso Propyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) Title: Organic compounds with a 4H-triazole skeleton, such as [Ir(iPrptz-3b)3] Metallic iridium complexes and tris[3-methyl-1-(2-methylphenyl)-5-phenyl [Ir(Mptz) 1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2, 4-Triazolate)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]) Organometallic iridium complexes with 1H-triazole skeletons such as fac-tris[ 1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridide Ir(iPrpmi)3], tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(I II) (abbreviation: [Ir(dmpimpt-Me)3]) Organometallic iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinium] To-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(CF3ppy)2(pic)]), bis[2-(4',6 '-Difluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetone Phenylpyridine derivatives with electron-withdrawing groups such as tonato (abbreviation: FIracac) These organometallic iridium complexes have the ligand It is a compound having an emission peak at 440 nm to 520 nm.

[0059] In addition, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)yl Ir(tBuppm)3, diacetylacetonate (6-Methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mp pm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4- Phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(ac ac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpiperidinyl [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenyl [Pyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)] ), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(II I) (abbreviation: [Ir(dppm)2(acac)]) Metal-iridium complexes and (acetylacetonato)bis(3,5-dimethyl-2-phenyl Rupyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac) ]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyridine Dinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]) Organometallic iridium complexes with pyrazine skeletons such as tris(2-phenylpyridinium) Nat-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 (I II) Acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(beta Tris[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]) (2-Phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq) 3]), bis(2-phenylquinolinato-N,C 2’ ) Iridium(III) acetylated A compound with a pyridine skeleton, such as setonate (abbreviation: [Ir(pq)2(acac)]) In addition to the organometallic iridium complexes, tris(acetylacetonato)(monophenanthroline)tetraacetate Rare earth metals such as rubium(III) (abbreviation: [Tb(acac)3(Phen)]) These are mainly compounds that exhibit green phosphorescence and have an emission wavelength of 500 nm to 6 The emission peak is at 100 nm. The body is particularly preferred because it is remarkably excellent in reliability and luminous efficiency.

[0060] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinyl] Nat[Iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis [4,6-Bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)irid Ir(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di( Naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]) iridium complexes of the genus acetylacetonato, bis(2,3,5-triphenylpyrazine) Iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2, 3,5-Triphenylpyrazinato)(dipivaloylmethanato)iridium(III)(abbreviation Name: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis (4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fd pq)2(acac)]) and other organometallic iridium complexes with pyrazine skeletons, Tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir (piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) Iridium (II I) Pyridyl acetylacetonate (abbreviation: [Ir(piq)2(acac)]) In addition to organometallic iridium complexes with iridium skeletons, 2,3,7,8,12,13,17,18 -Octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) Platinum complexes such as tris(1,3-diphenyl-1,3-propanedionato) (monophenyl Anthroline) europium(III) (abbreviation: [Eu(DBM)3(Phen)]), Tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthate Europium(III) (abbreviation: [Eu(TTA)3(Phen)]) These are compounds that exhibit red phosphorescence and have a wavelength of 60 The emission peak is between 0 nm and 700 nm. The rhodium complex can emit red light with good chromaticity.

[0061] In addition to the phosphorescent compounds described above, known phosphorescent light-emitting materials may be selected and used. stomach.

[0062] TADF materials include fullerene and its derivatives, acridine and its derivatives, and eosin. Derivatives of magnesium (Mg), zinc (Zn), cadmium (Cd) and other metals can also be used. (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (P d) and the like. The metal-containing porphyrin includes, for example, For example, the protoporphyrin-tin fluoride complex (SnF2(Pro to IX), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), Hematoporphyrin-Tin Fluoride Complex (SnF2(Hemato IX)), Copropor Phyllin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4M e)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etiopo Luphirin-Tin Fluoride Complex (SnF2(Etio I)), Octaethylporphyrin -platinum chloride complex (PtCl2OEP) and the like.

[0063] [ka]

[0064] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenyl)-2-phenylpropanediol having the following structural formula is also available. phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine ( Abbreviation: PIC-TRZ) and 9-(4,6-diphenyl-1,3,5-triazine-2- yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzT zn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-3-yl 4,6-diphenyl-1,3,5-triazine (abbreviation Name: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl ]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4 -(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5- Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-di Methyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACR XTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl] Sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[a Clidine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc. Heterocyclic compounds having either or both of an excess type heteroaromatic ring and an π-electron deficient type heteroaromatic ring are also used. The heterocyclic compound may be a π-electron rich heteroaromatic ring or a π-electron deficient heteroaromatic ring. Since it has an aromatic ring, it has high electron transport properties and hole transport properties, which is preferable. Among the skeletons that have a toe-shaped heteroaromatic ring, the pyridine skeleton, the diazine skeleton (pyrimidine skeleton, The arylazine, pyridazine, and triazine skeletons are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrimidine skeleton, The thiopyrazine and benzothienopyrazine skeletons are preferred because they have high acceptor properties and good reliability. Among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeletons and pheno The xanthazine skeleton, the phenothiazine skeleton, the furan skeleton, the thiophene skeleton, and the pyrrole skeleton It is preferable that the compound has at least one of the above skeletons because the compound is stable and reliable. The furan skeleton is a dibenzofuran skeleton, and the thiophene skeleton is a dibenzothiophene skeleton. The pyrrole skeleton is preferably an indole skeleton, a carbazole skeleton, or a cyclohexyloxycarbonyl skeleton. carbazole skeleton, indolocarbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H- A carbazol-3-yl)-9H-carbazole skeleton is particularly preferred. A substance in which a π-type heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is called a π-electron-rich heteroaromatic ring. The electron donating property of the ring and the electron accepting property of the π-electron deficient heteroaromatic ring are both strong, and the S1 and T1 levels Since the energy difference between the levels is small, thermally activated delayed fluorescence can be obtained efficiently. It is preferable that an electron-withdrawing group such as a cyano group is used instead of the π-electron-deficient heteroaromatic ring. In addition, the π-electron-rich skeleton may be an aromatic amine skeleton, a fluorine-containing skeleton, or the like. A phenazine skeleton or the like can be used. In addition, a xanthene skeleton can be used as a π-electron deficient skeleton. , thioxanthene dioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazoline skeleton azole skeleton, anthraquinone skeleton, boron-containing skeletons such as phenylborane and boranthrene, Aromatic rings or heterocyclic rings having nitrile or cyano groups such as benzonitrile or cyanobenzene Aromatic rings, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc. In this way, the π-electron deficient heteroaromatic ring and the π-electron rich heteroaromatic ring can be used. Using a π-electron deficient skeleton and a π-electron rich skeleton in place of at least one of the aromatic rings can be done.

[0065] [ka]

[0066] The TADF material is a substance represented by the following general formulas (G1) to (G11). It is preferable.

[0067] [ka]

[0068] [ka]

[0069] In the above general formula (G1), R 1 ~R 5 at least one of represents a cyano group; R 1 ~R 5At least one of the groups is a substituted or unsubstituted 9-carbazolyl group, Unsubstituted 1,2,3,4-tetrahydro-9-carbazolyl group, substituted or unsubstituted 1 -indolyl group, or a substituted or unsubstituted diarylamino group, and the remaining R 1 ~ R 5 each independently represents a hydrogen atom or a substituent.

[0070] In addition, in the above general formula (G2), R 11 and R 12 are each independently a hydrogen atom or any substituent, and A is an optionally substituted heteroaryl group or At least one arylamino group, which may have a substituent, is directly or indirectly bonded to another aromatic group. represents a substituent bonded to the 4-carbon atom of the pyridine ring via

[0071] In addition, in the above general formula (G3), Ar 1 ~Ar 3 represents an aryl group, one is substituted with a dibenzo-1,4-oxazine group or a dibenzo-1,4-thiazine group It represents an aryl group.

[0072] In the above general formula (G4), X is a substituted or unsubstituted aromatic hydrocarbon group, or an unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or an aromatic a substituted aromatic hydrocarbon group, an aromatic heterocyclic group, or a condensed polycyclic aromatic group; represents a di-substituted amino group, and Y is a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, or a cyano atom. a group, a nitro group, a linear or branched chain having 1 to 6 carbon atoms which may have a substituent an optionally substituted C cycloalkyl group; Optionally substituted straight-chain or branched alkenyl group having 2 to 6 carbon atoms a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent; an oxy group, an optionally substituted C cycloalkyloxy group, Substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted aromatic or unsubstituted condensed polycyclic aromatic group, substituted or unsubstituted aryloxy group, or aromatic a substituted aromatic hydrocarbon group, an aromatic heterocyclic group, or a condensed polycyclic aromatic group; represents a disubstituted amino group, and R 21 , R 22 , R 25 ~R 28 are mutually identical but different Each of them may independently be a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent; a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent; A linear or branched alkenyl group having 2 to 6 carbon atoms, which may have a substituent a linear or branched alkyloxy group having 1 to 6 carbon atoms, optionally having an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted A substituted condensed polycyclic aromatic group, a substituted or unsubstituted aryloxy group, or an aromatic hydrocarbon a disubstituted group selected from a cyclic group, an aromatic heterocyclic group, or a condensed polycyclic aromatic group; A substituted amino group which is a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. They may be bonded to each other via a substituent to form a ring.

[0073] In addition, in the above general formula (G5), A 1 ~A 3 are each independently a substituted or unsubstituted dibenzo Represents the zofranyl group.

[0074] In addition, in the above general formula (G6), R 31 ~R 34 and a to h are each independently and a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted an alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or represents an amino group.

[0075] In addition, in the above general formula (G7), R 41 ~R 48 are each independently a hydrogen atom or an electron At least one of the donor groups represents an electron donor group. R 49 ~R 56 are each independently water At least one of the electron-withdrawing groups is a triazino group or a nitrogen atom. represents an electron-withdrawing group other than R 41 ~R 56 11 to 14 of these are hydrogen atoms .

[0076] In addition, in the above general formula (G8), R 61 ~R 68 and R 77 are each independently a hydrogen atom R represents an electron donating group or an electron donating group. 69 ~R 76 teeth, Each Z is independently a hydrogen atom or an electron withdrawing group that does not have an unshared electron pair at the α-position. or =C=Y, where Y represents S, C(CN)2 or C(COOH)2. When Z is a single bond, R 69 ~R 76At least one of them has a lone pair of electrons at the α position. It is an electron-withdrawing group that does not have a molecular weight of 1.

[0077] In addition, in the above general formula (G9), the ring α is fused to the adjacent ring at any position as represented by the formula (g9-1 ), and ring β is condensed with the adjacent ring at any position, represented by formula (g9-2). In formula (G9) and (g9-2), Ar independently represents an aromatic hydrocarbon group or R in formula (G9) and (g9-1) is independently hydrogen or a group having 1 carbon atom. Alkyl groups with up to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, alkylthio groups with 1 to 10 carbon atoms , alkylamino groups having 1 to 10 carbon atoms, acyl groups having 2 to 10 carbon atoms, acyl groups having 7 to 20 carbon atoms Ralalkyl groups, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms. is a monovalent substituted or unsubstituted aromatic 6-membered heterocyclic group having 3 to 30 carbon atoms. n is an integer of 1 to 4, and adjacent substituents may be bonded to each other to form a ring. Indicates a number.

[0078] In addition, in the above general formula (G10), X 1 , X 2 , X 3 may be the same or different, Each independently represents a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms, optionally having a group; a cycloalkyl group having 5 to 10 carbon atoms, optionally having a substituent; A linear or branched alkenyl group having 2 to 6 carbon atoms, which may have a substituent. a linear or branched alkyloxy group having 1 to 6 carbon atoms, Optionally, a substituted or unsubstituted cycloalkyloxy group having 5 to 10 carbon atoms; Aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed A polycyclic aromatic group, a substituted or unsubstituted aryloxy group, or an aromatic hydrocarbon group, a di-substituted amino group substituted with a group selected from an aromatic heterocyclic group or a condensed polycyclic aromatic group; and at least X 1 , X 2 , X 3 One of the following is a substituted or unsubstituted aromatic Aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed polycyclic aromatic groups an aromatic group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or a condensed polycyclic aromatic group; Ar is a disubstituted amino group substituted with a group 4 is substituted or unsubstituted a divalent aromatic hydrocarbon group, a substituted or unsubstituted divalent heteroaromatic hydrocarbon group, or represents a substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon group, R 81 ~R 86 , R 89 ~R 94 may be the same or different, and each independently represents a hydrogen atom, a deuterium atom, a fluorine atom, a nitrogen atom, a chlorine atom, a cyano group, a nitro group, a C-C- a linear or branched alkyl group having 5 to 6 carbon atoms which may have a substituent; 10 cycloalkyl groups, optionally substituted linear or or a branched alkenyl group, or a linear or branched alkenyl group having 1 to 6 carbon atoms which may have a substituent. or branched alkyloxy group, an optionally substituted C 5 to C 10 alkyl group, Cycloalkyloxy group, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted Aromatic heterocyclic groups, substituted or unsubstituted condensed polycyclic aromatic groups, substituted or unsubstituted aryl an aromatic hydrocarbon group, an aromatic heterocyclic group or a condensed polycyclic aromatic group; A disubstituted amino group substituted with a group selected from the group consisting of a single bond, substituted or unsubstituted They may be bonded to each other via a methylene group, an oxygen atom or a sulfur atom to form a ring.

[0079] In addition, in the above general formula (G11), R 101 ~R 104 are each independently substituted or unsubstituted. Substituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted ar R represents an alkyl group or a substituted or unsubstituted cycloalkyl group; 105 and R 106 each independently represents a substituted or unsubstituted alkyl group; R 107 , R 108 and R 10 9 each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group; group, n1 to n4 and n7 each independently represent an integer of 0 to 4, and n5 and n6 and n7 each independently represent an integer of 0 to 3; n8 and n9 each independently represent an integer of 0 to 5; R 101 ~R 109 n1 to n9 are 2 or more. When it is an integer, multiple R 101 may be the same or different, R 102 ~R 109 The same applies to.

[0080] In addition, TADF materials have a small difference between the S1 and T1 levels, and can be triple-phased by reverse intersystem crossing. The function of converting energy from first excitation energy to singlet excitation energy Therefore, the triplet excitation energy can be converted to a single state by a small amount of thermal energy. It is possible to upconvert to singlet excited energy (reverse intersystem crossing), and efficiently convert singlet excited states It is possible to generate triplet excitation energy and convert it into luminescence. .

[0081] In addition, exciplexes (complexes) that form excited states with two types of substances The difference between the S1 and T1 levels is extremely small. As a TADF material capable of converting triplet excitation energy into singlet excitation energy, It has all the functions.

[0082] As an index of the T1 level, the phosphorescence observed at low temperatures (e.g., from 77 K to 10 K) The TADF material has a fluorescence spectrum at the short wavelength end. Draw a tangent line at the wavelength of the extrapolated line and define the energy of the wavelength as the S1 level. When a tangent line is drawn at the base of the short wavelength side and the energy of the wavelength of the extrapolated line is set as the T1 level, The difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less. It is more preferable that:

[0083] In addition, when a TADF material is used as the emission center material, the S1 level of the host material is The T1 level of the host material is preferably higher than the S1 level of the TADF material. A level higher than 1 is preferred.

[0084] The host material of the light-emitting layer may be a material having an electron transporting property or a material having a hole transporting property. Various carrier transport materials can be used, such as TADF materials.

[0085] As a material having hole transport properties, 4,4'-bis[N-(1-naphthyl)-N-phenylene N,N'-bis(3-methylphenyl)-N, N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-Bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenyla 4-phenyl-4'-(9-phenylfluorene) -9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9- mBPAFLP, 4-Fu phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine ( Abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazone PCBBi1BP, 4-(1-naphthalene-3-yl)triphenylamine ethyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine ( Abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H -Carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl 4-(9-phenyl-9H-carbazol-3-yl)phenyl N-phenyl-N-[4-(9- Phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fu Compounds with an aromatic amine skeleton, such as PCBASF 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N- Carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl) 3,3'-bis(9-phenyl- 9H-carbazole (abbreviation: PCCP) and other compounds with a carbazole skeleton, ,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene)(abbreviation Name: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-ful oren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4 -[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzyl Compounds with a thiophene skeleton, such as dibenzothiophene (abbreviation: DBTFLP-IV), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation :DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl )phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) Among the above, compounds having an aromatic amine skeleton are preferred. Compounds having a carbazole skeleton have good reliability and high hole transport properties. This is also preferable because it contributes to reducing the driving voltage. Organic compounds may also be used.

[0086] As an example of a material having electron transport properties, bis(10-hydroxybenzo[h]quinoli Nat)beryllium(II)(abbreviation:BeBq2), bis(2-methyl-8-quinolinolato )(4-phenylphenolato)aluminum(III)(abbreviation: BAlq), bis(8- Quinolinolato)zinc(II)(abbreviation:Znq), bis[2-(2-benzoxazolyl) phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl) Metal complexes such as phenolato zinc(II) (abbreviation: ZnBTZ) and 2-(4-biphenyl (aryl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation : PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl) phenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butyl) rt-Butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (Abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl) phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5 -benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TP BI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H -Benzimidazole (abbreviation: mDBTBIm-II), 2-{4-[9,10-di(na phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide Heterocyclic compounds with polyazole skeletons such as 2-[3 -(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation : 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl nyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II ), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[ f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthroline 4,6-bis(phenyl-9-yl)pyrimidine (abbreviation: 4,6mPnP2Pm), [3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm -II) and other heterocyclic compounds with diazine skeletons, such as 3,5-bis[3-(9H- 35DCzPPy, 1,3,5-Triphenyl-9-yl)pyridine Pyridines such as 3-(3-pyridyl)-phenyl-benzene (abbreviation: TmPyPB) Among the above, heterocyclic compounds having a diazine skeleton are preferred. Compounds having a pyridine skeleton and heterocyclic compounds having a pyridine skeleton are preferred because of their high reliability. Heterocyclic compounds with an azine (pyrimidine or pyrazine) skeleton have high electron transport properties and are It also contributes to voltage reduction.

[0087] The TADF materials that can be used as host materials are the same as those listed above. When a TADF material is used as a host material, the The triplet excitation energy is converted to singlet excitation energy by reverse intersystem crossing, and The luminous efficiency of the light-emitting element can be improved by transferring energy to the luminescent center substance. In this case, the TADF material acts as an energy donor, and the luminescent center acts as an energy absorber. It functions as a receptor.

[0088] This is extremely effective when the luminescent center substance is a fluorescent substance. In order to obtain high luminous efficiency, the S1 level of the TADF material must be higher than the S1 level of the fluorescent material. The T1 level of the TADF material is preferably higher than the S1 level of the fluorescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent material. It is preferable that the level is higher.

[0089] In addition, T that emits light that overlaps with the lowest energy absorption band of the fluorescent material It is preferable to use ADF materials. This allows the TADF material to be converted into a fluorescent material. This is preferable because the transfer of excitation energy becomes smooth and light emission can be obtained efficiently.

[0090] In addition, singlet excitation energy is efficiently generated from triplet excitation energy by reverse intersystem crossing. In order for this to happen, it is preferable for carrier recombination to occur in the TADF material. The triplet excitation energy generated in the DF material is transferred to the triplet excitation energy of the fluorescent material. For this purpose, it is preferable that the fluorescent substance has a luminophore ( It is preferable that the compound has a protecting group around the skeleton that causes light emission. A substituent having no carbon atom is preferable, and a saturated hydrocarbon is preferable. Specifically, the substituent has 3 to 10 carbon atoms. The alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, A trialkylsilyl group having a number of 3 to 10 is preferred, and a group having a plurality of protecting groups is more preferred. Substituents without π bonds have poor carrier transport function, and therefore have poor carrier transport and The distance between the TADF material and the luminophores of the fluorescent material can be reduced without affecting carrier recombination. Here, the luminophore is the molecule that causes the emission of light in a fluorescent substance. The luminophore preferably has a skeleton with a π bond and contains an aromatic ring. It is preferable that the aromatic ring has a condensed aromatic ring or a condensed heteroaromatic ring. The heterocyclic aromatic rings include phenanthrene skeletons, stilbene skeletons, acridone skeletons, and pheno In particular, the naphthalene skeleton, the anthracene skeleton, and the like can be used. skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetracene skeleton, pyrene skeleton It has a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, and a naphthobisbenzofuran skeleton. Such fluorescent substances are preferred because they have high fluorescence quantum yields.

[0091] When a fluorescent substance is used as the luminescence center substance, the host material is preferably an anthracene skeleton A material having an anthracene skeleton is preferably used as a host material for a fluorescent material. When used as such, it is possible to realize a light-emitting layer having good light-emitting efficiency and durability. As the anthracene skeleton material to be used, diphenylanthracene skeleton is used. In particular, substances with a 9,10-diphenylanthracene skeleton are chemically stable. In addition, when the host material has a carbazole skeleton, the hole injection / transport property is high. However, the benzocarbazole skeleton in which a benzene ring is further condensed to the carbazole is preferable. When the siloxane is included, the HOMO becomes shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter. In particular, when the host material contains a dibenzocarbazole skeleton, The HOMO is shallower than that of rutile, by about 0.1 eV, making it easier for holes to enter. It is also preferable because it has excellent transportability and high heat resistance. Among these, 9,10-diphenylanthracene skeletons and carbazole skeletons (and It is a substance that simultaneously has a benzocarbazole skeleton or a dibenzocarbazole skeleton. From the viewpoint of the hole injection and transport properties, a benzofluorene skeleton was used instead of a carbazole skeleton. Examples of such materials include 9-fluorene and dibenzofluorene structures. phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazone PCzPA, 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9 H-Carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthraceni 7-[4-(10-phenyl)phenyl]-9H-carbazole (abbreviation: CzPA), -9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgD BCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzene Zo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10 -{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}an Trathane (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl) phenyl]anthracene (abbreviation: αN-βNPAnth) and the like. In particular, CzP A, cgDBCzPA, 2mBnfPPA, and PCzPA show very good properties. This is the preferred choice.

[0092] The host material may be a mixture of a plurality of substances. When used, a material having an electron transporting property and a material having a hole transporting property may be mixed. It is preferable to mix a material having an electron transporting property with a material having a hole transporting property. In this way, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. The weight ratio of the content of the material having a hole transporting property to the content of the material having an electron transporting property is The ratio of the material having hole transport properties to the material having electron transport properties may be from 1:19 to 19:1.

[0093] A phosphorescent material can be used as a part of the mixed material. When a fluorescent substance is used as the luminescent center material, the luminescent substance is excited with excitation energy. It can be used as an energy donor that provides

[0094] In addition, these mixed materials may form an exciplex. The exciplex is a light-emitting material. The luminescence of the exciplex is such that it overlaps with the wavelength of the lowest energy absorption band of the By selecting such a combination, energy transfer becomes smooth and light emission can be obtained efficiently. In addition, the use of this configuration is also preferable because the driving voltage can be reduced.

[0095] At least one of the materials forming the exciplex may be a phosphorescent material. In this way, triplet excitation energy is efficiently converted to singlet excitation energy by reverse intersystem crossing. can be converted to

[0096] As a combination of materials that efficiently form exciplexes, HO It is preferable that the MO level of the material having electron transport properties is equal to or higher than the HOMO level of the material having hole transport properties. When the LUMO level of the material having the electron transport property is higher than the LUMO level of the material having the electron transport property, It is preferable that the LUMO level and the HOMO level of the material are determined by cyclic voltammetry. From the electrochemical properties (reduction potential and oxidation potential) of the material measured by CV measurement It can be derived.

[0097] The formation of an exciplex is based on, for example, the emission spectrum of a material having hole transport properties, the electron transport properties, The emission spectrum of the material having the above structure and the emission spectrum of the mixed film of these materials are shown in Fig. In comparison, the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material ( This can be confirmed by observing the phenomenon of a new peak on the long wavelength side. Alternatively, the transient photoluminescence (PL) of a material with hole transport properties and the electron transport properties The transient PL of the materials with the same properties and the transient PL of the mixed film of these materials were compared. The transient PL lifetime of the film has a longer-lived component than the transient PL lifetime of each material, or has a delayed component. This can be confirmed by observing the difference in the transient response, such as the percentage of In addition, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, the transient EL of a material with hole transport properties and the transient E of a material with electron transport properties are By comparing the transient EL of the L and the mixed films and observing the difference in the transient response, The formation of the exciplex can be confirmed.

[0098] The electron transport layer 114 is provided in contact with the light emitting layer 113. A seventh organic compound having a molecular transport property and a HOMO level of -6.0 eV or more. The seventh organic compound is an organic compound having an electron transporting property and contains an anthracene skeleton. In addition, the electron transport layer 114 preferably further comprises an alkali metal or an alkaline earth metal. That is, the electron transport layer 114 may include an eighth material that is an organic complex of the group It may be composed of the seventh organic compound alone, or a mixture of the seventh organic compound and the eighth substance. The seventh organic compound may be composed of a mixture of the seventh organic compound and other substances, such as the seventh organic compound. stomach.

[0099] It is more preferable that the seventh organic compound contains an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing five-membered ring skeleton. is a ring that contains two heterocyclic rings, such as pyrazole, imidazole, oxazole, and thiazole. It is particularly preferred that the ring has a nitrogen-containing five-membered ring structure containing the atom.

[0100] Other organic compounds having electron transport properties that can be used as the seventh organic compound include The organic compound having an electron transporting property that can be used as the host material or the fluorescent material The organic compounds listed above can be used as host materials for light-emitting substances. It is possible.

[0101] As the organic complex of the alkali metal or alkaline earth metal, an organic complex of lithium is preferably used. is preferred, and 8-hydroxyquinolinato lithium (abbreviation: Liq) is particularly preferred.

[0102] The material constituting the electron transport layer 114 has an electric field strength [V / cm] square root of 600 When the electron mobility is 1×10 -7 cm 2 / Vs or more 5×10 -5 cm 2 / V It is preferable that the length is equal to or less than s.

[0103] The square root of the electric field strength [V / cm] of the material constituting the electron transport layer 114 is 600. In this case, the electron mobility is determined by the electric field strength of the sixth organic compound or the material constituting the light-emitting layer 113. It is preferable that the electron mobility is smaller than the electron mobility when the square root of the electric field strength [V / cm] is 600. By reducing the transportability of electrons in the electron transport layer, the amount of electrons injected into the light-emitting layer can be controlled. This makes it possible to control the amount of electrons in the light-emitting layer, thereby preventing the light-emitting layer from becoming excessively electron-rich.

[0104] When the light-emitting layer becomes in an electron excess state, a part of the light-emitting region 113-1 becomes By limiting the area, the burden on that area increases, accelerating deterioration. The lifetime and luminous efficiency are also reduced when electrons are unable to recombine and pass through the light-emitting layer. In one embodiment of the present invention, the electron transport property of the electron transport layer 114 is reduced, so that the electron transport layer 114 shown in FIG. As shown in B), the light-emitting region 113-1 is expanded, and the load on the material constituting the light-emitting layer 113 is dispersed. By doing so, it is possible to provide a light emitting device having a long life and good luminous efficiency.

[0105] In addition, in a light-emitting device having such a configuration, a driving test under a constant current density condition is performed. In the luminance degradation curve obtained by the above method, a shape having a maximum value may be observed. That is, the deterioration curve of the light-emitting device according to one embodiment of the present invention shows that the luminance increases with time. Light-emitting devices that exhibit this type of degradation behavior are known as This increase in brightness can offset the initial degradation that occurs during the initial period of operation. This results in a light-emitting device with small initial deterioration and extremely good operating life. It becomes possible.

[0106] When the derivative of such a deterioration curve with a maximum value is taken, there is a part where the value is 0. In other words, the light-emitting element according to one embodiment of the present invention has a portion where the differential of the deterioration curve is zero. The device can be a light emitting device with small initial deterioration and extremely long life.

[0107] As shown in Figure 3(A), this phenomenon is called non-radiative recombination, which does not contribute to light emission. This phenomenon is believed to be caused by something that occurs in the region 114-1. In the case of a bright light-emitting device, the hole injection barrier is small at the initial stage of operation, and the electron transport layer 1 The relatively poor electron transport properties of 14 allow the light emitting region 113-1 (i.e., the recombination region) is formed in a state close to the electron transport layer 114 side. Since the HOMO level of the organic compound 7 is relatively high at -6.0 eV or higher, some of the holes are charged. The electron transport layer 114 is reached, and recombination also occurs in the electron transport layer 114, resulting in a non-radiative recombination region. The region 114-1 is formed. This phenomenon occurs when the sixth organic compound and the seventh organic compound This can also occur when the difference in HOMO levels is within 0.2 eV.

[0108] Here, as the driving time passes, the carrier balance changes, As shown in FIG. 3B, the light-emitting region 113-1 (recombination region) moves to the hole transport layer 112 side. As the non-radiative recombination region 114-1 decreases, the energy of the recombined carriers This allows the light emitted from the substrate to contribute effectively to the emission of light, resulting in an increase in brightness. By offsetting the sudden drop in brightness that occurs when the device is first driven, known as initial degradation, It is therefore possible to provide a light emitting element which is small in size and has a long operating life.

[0109] In addition, by suppressing the initial deterioration, one of the major weaknesses of OLED devices is The problem of image sticking is still being debated, and the aging method before shipment is being used to reduce it. It is possible to significantly reduce the time.

[0110] A light-emitting device according to one embodiment of the present invention having the above-described structure has a long lifetime. It is possible to make the following:

[0111] (Embodiment 2) Next, examples of the detailed structure and materials of the above-mentioned light-emitting device will be described. As described above, the light-emitting device is made of a plurality of layers between a pair of electrodes, an anode 101 and a cathode 102. The EL layer 103 is provided with a hole injection layer 104 at least on the anode 101 side. 111, a first hole transport layer 112-1, a second hole transport layer 112-2, a light emitting layer 113 and and an electron transport layer.

[0112] The layers other than the EL layer 103 are not particularly limited, and may be a hole injection layer, a hole transport layer, etc. layer, electron transport layer, electron injection layer, carrier block layer, exciton block layer, charge generation layer, etc. , various layer structures can be applied.

[0113] The anode 101 is made of a metal, an alloy, or a conductive compound having a large work function (specifically, 4.0 eV or more). It is preferable to form the insulating layer using a material such as a material having a molecular weight of 100 or more, or a mixture thereof. Indium Tin Oxide (ITO), silicon or Indium oxide-tin oxide, indium oxide-zinc oxide, oxide Examples include indium oxide containing tungsten and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but they can also be formed by sol-gel methods. As an example of the manufacturing method, indium oxide-zinc oxide The sputtering was performed using a target containing 1 to 20 wt% zinc oxide in indium oxide. Also, the method of forming the tungsten oxide and zinc oxide is Indium oxide (IWZO) is a material that is made by mixing 0.5 to 5 tungsten oxide with indium oxide. The target contained 0.1-1 wt% zinc oxide. Other materials include gold (Au), platinum (Pt), nickel (Ni), and titanium. W, Chromium (Cr), Molybdenum (Mo), Iron (Fe), Cobalt (Co) , copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride), etc. Graphene can also be used. Representative materials for forming the electrode have been listed above. In one embodiment of the present invention, the hole injection layer 1 11, an organic compound having a hole transporting property and a substance exhibiting an electron accepting property with respect to the organic compound Since a composite material containing the above is used, the electrode material can be selected regardless of the work function.

[0114] In this embodiment, the laminated structure of the EL layer 103 is as shown in FIG. Injection layer 111, first hole transport layer 112-1, second hole transport layer 112-2, light emitting layer 11 3. A structure having an electron injection layer 115 in addition to the electron transport layer 114, and as shown in FIG. As shown in FIG. 1, the hole injection layer 111, the first hole transport layer 112-1, the second hole transport layer 112-2, Two types of structures are available: a structure having a light-emitting layer 113, an electron transport layer 114, and a charge generation layer 116. The materials constituting each layer are specifically described below.

[0115] A hole injection layer 111, a hole transport layer 112 (a first hole transport layer 112-1, a second hole transport layer 112-2), the light-emitting layer 113 and the electron transport layer 114 are described in detail in the first embodiment. Therefore, the repetitive description will be omitted, and please refer to the description in the first embodiment.

[0116] Between the electron transport layer 114 and the cathode 102, lithium fluoride (LiF2O3) is provided as the electron injection layer 115. Alkali such as iF, cesium fluoride (CsF), calcium fluoride (CaF2), etc. A layer containing a metal or an alkaline earth metal or a compound thereof may be provided. 5 is a layer made of a substance having an electron transporting property, in which an alkali metal or an alkaline earth metal or It is also possible to use a material containing these compounds or an electride. For example, a material in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum is Some examples include:

[0117] In addition, a charge generating layer 1 is formed between the electron transport layer 114 and the cathode 102 instead of the electron injection layer 115. The charge generating layer 116 can be generated by applying a potential. A layer capable of injecting holes into a layer in contact with the cathode side of the layer and electrons into a layer in contact with the anode side of the layer. The charge generating layer 116 includes at least a P-type layer 117. The above-mentioned composite material may be used to form the hole injection layer 111. It is preferable that the P-type layer 117 is formed of the above-mentioned material constituting the composite material. The P-type layer 1 may be formed by laminating a film containing an acceptor material and a film containing a hole transport material. By applying a potential to the cathode 102, electrons are transported to the electron transport layer 114. Holes are injected and the light emitting device operates.

[0118] In addition to the P-type layer 117, the charge generating layer 116 also includes an electron relay layer 118 and an electron injection buffer layer 119. Preferably, one or both of layers 119 are provided.

[0119] The electron relay layer 118 contains at least a substance having an electron transport property, and the electron injection buffer layer 1 The function of the junction is to prevent the interaction between the P-type layer 117 and the P-type layer 119 and to transfer electrons smoothly. The LUMO level of the substance having electron transport properties contained in the relay layer 118 is The LUMO level of the electron-accepting substance in the electron transport layer 114 is in contact with the charge generating layer 116. It is preferable that the LUMO level of the electron relay layer 118 is between the LUMO level of the material contained in the layer. The specific energy level of the LUMO level in the electron transport material used in The potential is set to -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less. The electron relay layer 118 may be made of a phthalocyanine-based material having electron transport properties. It is preferred to use a metal complex having a metal-oxygen bond and an aromatic ligand.

[0120] The electron injection buffer layer 119 may include an element selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, and These compounds (alkali metal compounds (oxides such as lithium oxide, halides, lithium carbonate, etc.) (including carbonates such as tium and cesium carbonate), alkaline earth metal compounds (oxides, halogens, etc.) compounds of rare earth metals (including oxides, halides, carbonates) or compounds of rare earth metals (including oxides, halides, carbonates) It is possible to use a material with high electron injection properties such as fluorine.

[0121] The electron injection buffer layer 119 contains a substance having an electron transporting property and an electron donating substance. When formed, the electron donor is an alkali metal, an alkaline earth metal, a rare earth metal, Metals and their compounds (alkali metal compounds (oxides such as lithium oxide, halogens cations, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (oxides compounds of rare earth metals (including oxides, halides, carbonates) , including carbonates), as well as tetrathianaphthacene (abbreviation: TTN), nickelocene, deca Organic compounds such as methylnickelocene can also be used. The material is the same as that of the electron transport layer 114 described above. It is possible.

[0122] The material for forming the cathode 102 is gold, which has a small work function (specifically, 3.8 eV or less). Metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) and cesium (Cs). , and elements such as magnesium (Mg), calcium (Ca), and strontium (Sr) Elements belonging to Group 1 or 2 of the periodic table and alloys containing these elements (MgAg, AlL i), europium (Eu), ytterbium (Yb), and other rare earth metals, and However, an electron injection layer is provided between the cathode 102 and the electron transport layer. By providing this, regardless of the magnitude of the work function, Al, Ag, ITO, silicon or oxide can be used. Various conductive materials such as indium oxide-tin oxide containing silicon dioxide can be used as the cathode 102. There can be. These conductive materials can be applied by dry methods such as vacuum deposition and sputtering, inkjet printing, It is possible to form the film by using a spin coating method, etc. Also, it is possible to form the film by using a wet sol-gel method. Alternatively, the metal material may be used in a wet process to form the metal layer.

[0123] The EL layer 103 can be formed by a variety of methods, including dry and wet methods. For example, vacuum deposition, gravure printing, offset printing, screen printing, etc. A printing method, an ink jet method, a spin coating method or the like may also be used.

[0124] Moreover, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0125] The configuration of the layers provided between the anode 101 and the cathode 102 is not limited to the above. However, the proximity of the light-emitting region to the metals used in the electrodes and carrier injection layer In order to suppress the quenching caused by the hole, the hole is located at a position away from the anode 101 and the cathode 102. It is preferable that the phosphorus be provided with a light-emitting region in which the phosphorus and the electron recombine.

[0126] In addition, recombination in the hole transport layer or electron transport layer in contact with the light emitting layer 113, particularly in the light emitting layer 113 The carrier transport layer close to the region suppresses the energy transfer from excitons generated in the light-emitting layer. Therefore, the band gap is determined by the luminescent material constituting the luminescent layer or the luminescent material contained in the luminescent layer. It is preferable that the material is made of a substance having a larger band gap than the material. I wish.

[0127] Next, we developed a light-emitting device (a stacked element, a tandem element) that has a structure in which multiple light-emitting units are stacked. The embodiment of the light-emitting device (also referred to as a "light-emitting diode") will be described with reference to FIG. A light-emitting device having multiple light-emitting units between an electrode and a cathode. The EL layer 103 has a structure similar to that of the EL layer 103 shown in FIG. The light emitting device shown in FIG. 1(A) or The light-emitting device shown in FIG. 1B is a light-emitting device having one light-emitting unit. It can be said.

[0128] In FIG. 1C, a first light-emitting unit 511 and a second light-emitting unit 512 are disposed between an anode 501 and a cathode 502. The second light-emitting unit 512 is laminated, and the first light-emitting unit 511 and the second light-emitting unit A charge generating layer 513 is provided between the anode 501 and the cathode 502. These correspond to the anode 101 and the cathode 102 in FIG. 1(A), respectively, and are described in the explanation of FIG. 1(A). The same as that described above can be applied to the first light-emitting unit 511 and the second light-emitting unit 512. The optical units 512 may be of the same construction or of different constructions.

[0129] When a voltage is applied between the anode 501 and the cathode 502, the charge generating layer 513 emits light from one of the light emitting units. The luminescent unit has a function of injecting electrons into one luminescent unit and injecting holes into the other luminescent unit. In 1(C), when a voltage is applied so that the anode potential is higher than the cathode potential, In this case, the charge generating layer 513 injects electrons into the first light emitting unit 511 and Any material capable of injecting holes into the gate 512 may be used.

[0130] The charge generation layer 513 is formed to have the same structure as the charge generation layer 116 described in FIG. The composite material of an organic compound and a metal oxide has the following advantages: Since the light-emitting unit has excellent characteristics, it can be driven at low voltage and low current. When the anode side surface of the charge generating layer 513 contacts the charge generating layer 513, the charge generating layer 513 becomes the light emitting unit. Since the EL element can also function as a hole injection layer for the light-emitting unit, the light-emitting unit does not need to have a hole injection layer. This is also good.

[0131] In addition, when the charge generating layer 513 is provided with the electron injection buffer layer 119, the electron injection buffer Since the anode layer 119 plays the role of an electron injection layer in the light-emitting unit on the anode side, the light-emitting The unit does not necessarily need to have an electron injection layer.

[0132] Although the light-emitting device having two light-emitting units has been described with reference to FIG. 1C, the light-emitting device having three or more light-emitting units may be used. The same can be applied to a light-emitting device in which the above light-emitting units are stacked. As in the light-emitting device according to the present embodiment, a plurality of light-emitting units are electrically connected between a pair of electrodes. By separating the layers with the generation layer 513, high-luminance light emission is possible while keeping the current density low. This allows the realization of an element with even longer life. In addition, it is possible to realize an element that can be driven at a low voltage and has low power consumption. The device can be realized.

[0133] In addition, by making the light color of each light-emitting unit different, the entire light-emitting device For example, a light-emitting device having two light-emitting units can be used to obtain light of a desired color. In the device, the first light-emitting unit emits red and green light, and the second light-emitting unit emits blue light. By obtaining a color, it is possible to obtain a light-emitting device that emits white light as a whole. In addition, examples of the configuration of a light-emitting device in which three or more light-emitting units are stacked include the following: The first light-emitting unit has a first blue light-emitting layer and the second light-emitting unit has a yellow or yellow-green light-emitting layer. The first light-emitting unit has a first color light-emitting layer and a second red light-emitting layer, and the third light-emitting unit has a second blue light-emitting layer. The tandem device may be a tandem device having the above-mentioned light-emitting device. As with the chair, white light can be obtained.

[0134] In addition, the above-mentioned EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and Each layer such as the charge generating layer and the electrodes can be formed by, for example, a deposition method (including a vacuum deposition method), a droplet discharge method (including an inkjet method), etc. It can be formed by using methods such as ink jet printing, coating, and gravure printing. They can be used in a wide range of applications, including low molecular weight materials, medium molecular weight materials (including oligomers and dendrimers), and or polymeric materials.

[0135] (Embodiment 3) In this embodiment, light emission using the light emitting device described in the first and second embodiments is performed. The apparatus will now be described.

[0136] In this embodiment, the light-emitting device described in the embodiment 1 and the embodiment 2 is used to manufacture The light-emitting device will be described with reference to FIG. 4. FIG. 4(A) shows the light-emitting device. FIG. 4(B) is a cross-sectional view taken along lines AB and CD in FIG. 4(A). The device includes a drive circuit section (source The pixel portion 602 includes a driver circuit portion (gate line driver circuit) 603. In addition, 604 is a sealing substrate, 605 is a sealing material, and the inside surrounded by the sealing material 605 has become space 607.

[0137] The lead wiring 608 is connected to the source line driver circuit 601 and the gate line driver circuit 603. The wiring is for transmitting the signals to be input, and the FPC (flexible printed circuit board) is the external input terminal. Video signal, clock signal, start signal, reset signal, etc. from the 609 Although only the FPC is shown here, the FPC has a printed wiring board. The light emitting device in this specification may be a light emitting device. This includes not only the device itself, but also the state in which an FPC or PWB is attached to it. do.

[0138] Next, the cross-sectional structure will be described with reference to FIG. A source line driver circuit 601 and a pixel portion are formed. 6, one pixel in the pixel area 602 is shown.

[0139] The element substrate 610 may be made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like. FRP (Fiber Reinforced Plastics), PVF (Polyvinyl It is made using a plastic substrate made of materials such as fluoride, polyester, or acrylic. That's good.

[0140] The structure of the transistors used in the pixels and the driver circuits is not particularly limited. The transistor may be a top-type transistor or a staggered type transistor. The transistor may be a gate type transistor or a bottom gate type transistor. The semiconductor material is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and nitride. Gallium, etc., can be used. Alternatively, indium, such as In-Ga-Zn based metal oxides, Alternatively, an oxide semiconductor containing at least one of tungsten, gallium, and zinc may be used.

[0141] The crystallinity of the semiconductor material used in the transistor is not particularly limited. A semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a partially crystalline region If a semiconductor having crystallinity is used, the transistor This is preferable because it can suppress deterioration of the star characteristics.

[0142] Here, in addition to the transistors provided in the pixels and the driver circuits, It is preferable to use an oxide semiconductor for a semiconductor device such as a transistor. In particular, it is preferable to use an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor with a wider band gap than silicon, the off-state of the transistor can be improved. This can reduce the current in the negative-going state.

[0143] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn). In-M-Zn oxides (where M is Al, Ti, Ga, Ge, Y, Zr, Sn, It is preferable that the oxide semiconductor contains an oxide represented by the formula (1) of La, Ce or Hf. This is more preferable.

[0144] Here, an oxide semiconductor that can be used in one embodiment of the present invention will be described. .

[0145] Oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. As a non-single crystal oxide semiconductor, for example, CAAC-OS (c-axis axially aligned oxide semiconductor) gned crystalline oxide semiconductor), polycrystalline Nanocrystalline oxide semiconductor, nc-OS iconductor), pseudo-amorphous oxide semiconductor (a-like OS:amorph amorphous-like oxide semiconductor, and amorphous oxide semiconductor Conductors, etc.

[0146] CAAC-OS has a c-axis orientation and multiple nanocrystals are connected in the ab-plane direction. The crystal structure has distortion. The distortion is the area where multiple nanocrystals are connected. In the region, between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement, Indicates the point where the direction is changing.

[0147] Nanocrystals are basically hexagonal, but are not limited to regular hexagons and may be non-regular hexagons. In addition, the distortion may have a lattice arrangement such as a pentagon or a heptagon. In addition, in the CAAC-OS, clear grain boundaries (grain boundaries) are not observed even in the vicinity of the strain. It is difficult to confirm the presence of the crystal grains due to the distortion of the lattice arrangement. This is because the CAAC-OS has a lattice structure in the ab-plane direction. The oxygen atoms are not densely packed, and the bond distance between atoms is shortened by the substitution of metal elements. This is because distortion can be tolerated by changing the frequency band.

[0148] In addition, the CAAC-OS has a layer containing indium and oxygen (hereinafter, the In layer) and an element A layered crystal structure in which layers containing M, zinc, and oxygen (hereinafter referred to as the (M,Zn) layer) are stacked. Indium and element M tend to have a layered structure. It is possible, and when the element M in the (M,Zn) layer is replaced with indium, (In,M,Zn) Also, when the indium in the In layer is replaced with element M, (In,M ) layer.

[0149] CAAC-OS is a highly crystalline oxide semiconductor. Since it is difficult to confirm the grain boundaries, the decrease in electron mobility caused by the grain boundaries is unlikely to occur. In addition, the crystallinity of oxide semiconductors is degraded by the inclusion of impurities and the generation of defects. Therefore, CAAC-OS is designed to prevent impurities and defects (oxygen vacancies (V O :oxygen Therefore, CAA The physical properties of oxide semiconductors containing C-OS are stable. The oxide semiconductor has high heat resistance and high reliability.

[0150] The nc-OS is a nano-sized area (e.g., an area of ​​1 nm to 10 nm, especially 1 nm to 3 nm). The nc-OS has periodic atomic arrangement in the nanometer range. There is no regularity in the crystal orientation between the crystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, nc-OS may be considered to be a-like OS or amorphous oxide semiconductor. It may be indistinguishable from the above.

[0151] Note that indium, gallium, and zinc are used as a type of oxide semiconductor. In the case of IGZO, the nanocrystals mentioned above make it stable. In particular, IGZO tends to have difficulty growing crystals in air. , small crystals (e.g., For example, the nanocrystals mentioned above may be structurally more stable.

[0152] The a-like OS is an oxide semiconductor that has a structure between the nc-OS and the amorphous oxide semiconductor. Conductive. A-like OS has voids or low density regions. The ke-OS has a lower crystallinity than the nc-OS and CAAC-OS.

[0153] Oxide semiconductors have a variety of structures, each of which has different characteristics. Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and nc The compound may have two or more of -OS, CAAC-OS, and CAAC-OS.

[0154] In addition to the oxide semiconductors mentioned above, Cloud-Aligned Computing (CAC) osite)-OS may also be used.

[0155] CAC-OS is a material that has a conductive function in some parts and an insulating function in other parts. The material as a whole functions as a semiconductor. When used in the semiconductor layer of a material, the conductive function is to allow the electrons (or holes) that serve as carriers to flow. The function of insulation is to prevent the flow of electrons that act as carriers. The function of switching is achieved by making the function of switching and the function of insulating act in a complementary manner. On / Off function) can be added to CAC-OS. By separating the functions of each, the functions of both can be maximized.

[0156] The CAC-OS also has a conductive region and an insulating region. The insulating region has the above-mentioned insulating function. In some cases, the conductive and insulating regions are separated at the nanoparticle level. The conductive regions and the insulating regions may be unevenly distributed in the material. may be observed as a cloud-like formation with the edges blurred.

[0157] In addition, in CAC-OS, the conductive region and the insulating region are each 0.5 nm or more. When the particles are dispersed in the material with a size of 10 nm or less, preferably 0.5 nm to 3 nm, There is a match.

[0158] In addition, the CAC-OS is composed of components having different band gaps. For example, CAC-OS consists of a wide gap component originating from the insulating region and a conductive component originating from the conductive region. In this configuration, the carrier is When the carriers flow, the carriers mainly flow in the narrow gap component. The component with the gap acts complementary to the component with the wide gap to form a narrow gap. Carriers also flow into the component with a wide gap in conjunction with the component with a gap. When the CAC-OS is used in a channel forming region of a transistor, In the on-state, a high current drive capability, i.e., a large on-current, and a high field-effect mobility are obtained. It is possible.

[0159] That is, CAC-OS is a matrix composite. or metal matrix composite It can also be called.

[0160] By using the above-mentioned oxide semiconductor material for the semiconductor layer, the fluctuation of electrical characteristics is suppressed and reliability is improved. This makes it possible to realize highly reliable transistors.

[0161] In addition, the transistor having the above-described semiconductor layer can be used as a transistor due to its low off-state current. It is possible to hold the charge stored in the capacitor for a long period of time through such a transistor. By applying a transistor to each pixel, the gradation of the image displayed in each display area can be maintained while driving It is also possible to shut down the circuit. As a result, electronic devices with extremely low power consumption can be realized. It can be realized.

[0162] In order to stabilize the characteristics of the transistor, it is preferable to provide an undercoat film. Inorganic films such as silicon oxide film, silicon nitride film, silicon oxynitride film, and silicon nitride oxide film The insulating film can be formed in a single layer or a multilayer structure. CVD (Chemical Vapor Deposition) method (Plasma CVD method , thermal CVD method, MOCVD (Metal Organic CVD) method, etc.), ALD ( Formed using Atomic Layer Deposition (ALD), coating, printing, etc. It should be noted that the undercoat film does not have to be provided if it is not necessary.

[0163] The FET 623 indicates one of the transistors formed in the driver circuit section 601. The driving circuits are made up of various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment, a driver integrated type in which a driver circuit is formed on a substrate is shown. However, this is not necessarily required, and the drive circuit can be formed externally instead of on the substrate. .

[0164] The pixel section 602 includes a switching FET 611, a current control FET 612 and its driver. The pixel is formed of a plurality of pixels including an anode 613 electrically connected to the drain. However, the present invention is not limited to this, and the pixel section may be formed by combining three or more FETs and a capacitive element.

[0165] An insulator 614 is formed to cover the end of the anode 613. It can be formed by using a photosensitive acrylic.

[0166] In order to improve the coverage of the EL layer and the like to be formed later, the upper end of the insulator 614 is For example, the material of the insulator 614 is When a positive photosensitive acrylic is used, the radius of curvature (0. It is preferable that the insulating material 614 has a curved surface having a thickness of 2 μm to 3 μm. Either a negative-type photosensitive resin or a positive-type photosensitive resin can be used.

[0167] An EL layer 616 and a cathode 617 are formed on the anode 613. It is preferable to use a material having a large work function for the anode 613. For example, ITO film, or silicon-containing indium tin oxide film, 2 to 20 wt% oxide Indium oxide film containing zinc, titanium nitride film, chromium film, tungsten film, Zn film, Pt In addition to single-layer films such as titanium nitride films, laminated films of titanium nitride and aluminum-based films, A three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film can be used. In addition, the multilayer structure has low wiring resistance and good ohmic contact. It can also function as an anode.

[0168] The EL layer 616 is formed by deposition using a deposition mask, inkjet printing, or spin coating. The EL layer 616 is formed by the method described in the first and second embodiments. The EL layer 616 may include other materials such as: It may be a low molecular weight compound or a high molecular weight compound (including oligomers and dendrimers). .

[0169] Furthermore, the material used for the cathode 617 formed on the EL layer 616 is a material having a small work function. Materials that are suitable for use in the manufacture of semiconductors include Al, Mg, Li, Ca, and their alloys and compounds (MgAg, MgIn, It is preferable to use AlLi, etc. In the case of transmitting light, the cathode 617 is made of a thin metal film and a transparent conductive film (I TO, indium oxide containing 2-20wt% zinc oxide, indium tin containing silicon It is preferable to use a laminate of a metal oxide such as zinc oxide (ZnO).

[0170] The anode 613, the EL layer 616, and the cathode 617 form a light-emitting device. The light emitting device is the light emitting device described in the first and second embodiments. The pixel portion is formed with a plurality of light-emitting devices. The device includes the light-emitting device according to the first and second embodiments and other components. The light emitting device may include both a light emitting device having a light emitting diode and a light emitting device having a light emitting diode.

[0171] Furthermore, the sealing substrate 604 is bonded to the element substrate 610 with a sealant 605, A light emitting device is placed in a space 607 surrounded by a child substrate 610, a sealing substrate 604, and a sealant 605. The structure is provided with a chair 618. The space 607 is filled with a filling material. In some cases, the gas is filled with an inert gas (nitrogen, argon, etc.), and in other cases, it is filled with a sealing material. By forming a recess in the sealing substrate and providing a desiccant there, deterioration caused by moisture can be prevented. This is a preferable configuration because it is possible to suppress the degradation.

[0172] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is desirable that these materials are as impermeable to moisture and oxygen as possible. Materials used for the sealing substrate 604 include glass substrates, quartz substrates, and FRP (Fiber Reinforced Plastics). reinforced plastics), PVF (polyvinyl fluoride), polyester A plastic substrate made of, for example, polyester or acrylic can be used.

[0173] Although not shown in FIG. 4, a protective film may be provided on the cathode. The protective film may be an organic resin film or an inorganic A protective film may be formed so as to cover the exposed portion of the sealant 605. The protective film may be formed on the front and side surfaces of the pair of substrates, the sealing layer, the insulating layer, It can be provided to cover the exposed sides of the above.

[0174] The protective film can be made of a material that is difficult for impurities such as water to permeate. It is possible to effectively suppress the diffusion of impurities such as those mentioned above from the outside to the inside.

[0175] The materials that make up the protective film include oxides, nitrides, fluorides, sulfides, ternary compounds, and metals. Alternatively, polymers and the like can be used, for example, aluminum oxide, hafnium oxide, hafnium oxide, etc. Funium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide , titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide , cerium oxide, scandium oxide, erbium oxide, vanadium oxide or indium oxide Materials containing hafnium, aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, etc. Materials, nitrides containing titanium and aluminum, oxides containing titanium and aluminum , oxides containing aluminum and zinc, sulfides containing manganese and zinc, cerium and and sulfides containing strontium, oxides containing erbium and aluminum, yttrium Materials including, for example, oxides containing lithium and zirconium can be used.

[0176] The protective film should be formed using a film formation method that provides good step coverage. One such technique is atomic layer deposition (ALD). The ALD method can be used to form a protective It is preferable to use the ALD method for films that are dense and free of cracks and pinholes. It is possible to form a protective film having reduced defects or a uniform thickness. Damage to the processed member when forming the protective film can be reduced.

[0177] For example, by forming a protective film using the ALD method, it is possible to fabricate a surface with complex unevenness or a touch panel. It is possible to form a uniform protective film with few defects on the top, sides and back of the panel. .

[0178] As described above, the light-emitting devices described in the first and second embodiments were used to manufacture the Thus, a light emitting device having such a structure can be obtained.

[0179] The light emitting device of the present embodiment is the same as the light emitting device of the first and second embodiments. Since the semiconductor device uses the same material, it is possible to obtain a light-emitting device with excellent characteristics. The light emitting devices according to the first and second embodiments have a long life. Therefore, the light emitting device can have good reliability. Since the light emitting device using the light emitting device described in 2 has a good light emitting efficiency, it is a light emitting device with low power consumption. It may be an optical device.

[0180] In FIG. 5, a light-emitting device that emits white light is formed, and a colored layer (color filter) is provided. FIG. 5A shows an example of a full-color light-emitting device. An insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 1008, A first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, and a pixel portion 1040 , a driving circuit section 1041, anodes 1024W, 1024R, 1024G, and 10 24B, partition wall 1025, EL layer 1028, cathode 1029 of the light-emitting device, sealing substrate 103 1, sealing material 1032, etc. are shown.

[0181] In addition, in FIG. 5(A), the colored layers (red colored layer 1034R, green colored layer 1034G, blue The colored layer 1034B is provided on a transparent substrate 1033. 035 may be further provided. A transparent substrate 1 on which a colored layer and a black matrix are provided. The colored layer and the black matrix are fixed to the substrate 1001. The substrate 1035 is covered with an overcoat layer 1036. The light-emitting layer is a layer where light does not pass through the colored layers and goes out to the outside, and the light passes through the colored layers of each color and goes out to the outside. The light that does not pass through the colored layer is white, and the light that passes through the colored layer is red, green, or blue. This means that images can be expressed using four color pixels.

[0182] In FIG. 5B, the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer An example in which a layer (1034B) is formed between the gate insulating film (1003) and the first interlayer insulating film (1020) In this way, the colored layer is provided between the substrate 1001 and the sealing substrate 1031. is also good.

[0183] In the light emitting device described above, the light is taken in toward the substrate 1001 on which the FET is formed. The light emitting device has a bottom emission structure, but the light is taken in from the sealing substrate 1031 side. The light emitting device may have a structure in which the light is emitted from the top (top emission type). A cross-sectional view of a light-emitting device is shown in FIG. 6. In this case, a substrate 1001 that does not transmit light is used. The bottom is not connected to the FET and the anode of the light-emitting device until the connection electrode is fabricated. The third interlayer insulating film 1037 is then formed in the same manner as in the case of the m-emission type light emitting device. The insulating film is formed to cover the electrode 1022. This insulating film may also serve as a planarizing film. The interlayer insulating film 1037 may be formed using the same material as the second interlayer insulating film, or other known materials. It is possible.

[0184] The anodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are the anodes here. However, it may be formed as a cathode. In the case of an optical device, it is preferable that the anode is a reflective electrode. The EL layer 103 has the same structure as that described in the first and second embodiments, and In addition, the device structure is designed to obtain white light emission.

[0185] In the top emission structure shown in Fig. 6, the colored layers (red colored layer 1034R, green colored layer The sealing is performed by using a sealing substrate 1031 provided with a blue color layer 1034G and a blue color layer 1034B. The sealing substrate 1031 has a black matrix disposed between the pixels. A coloring layer (a red coloring layer 1034R, a green coloring layer 1034G, The blue colored layer 1034B) and the black matrix are covered by the overcoat layer 1036. The sealing substrate 1031 may be covered. In addition, although an example of full-color display using four colors, red, green, blue, and white, is shown here, the present invention is not limited to this. Alternatively, full color display may be performed using four colors, red, yellow, green, and blue, or three colors, red, green, and blue.

[0186] In a top emission type light emitting device, a microcavity structure can be suitably applied. Light-emitting devices with a microcavity structure use an anode as a reflective electrode and a cathode as a semi-transparent / semi-reflective electrode. The reflective electrode and the semi-transmissive / semi-reflective electrode are separated by at least The device has an EL layer, and at least has a light-emitting layer which serves as a light-emitting region.

[0187] The reflectance of the reflective electrode for visible light is 40% to 100%, preferably 70% to 100%. %, and its resistivity is 1×10 -2 The film is assumed to be less than Ωcm. The semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%. , and its resistivity is 1×10 -2 It is assumed that the film has a resistance of less than Ωcm.

[0188] The light emitted from the light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transparent and semi-reflective electrode. The light is reflected and resonates.

[0189] The light-emitting device is configured by changing the thickness of the transparent conductive film, the composite material, the carrier transport material, etc. By adjusting the thickness of the reflective electrode, the optical distance between the reflective electrode and the semi-transmissive and semi-reflective electrode can be changed. This strengthens the light of the resonating wavelength between the reflective electrode and the semi-transparent and semi-reflective electrode, and resonates. It can attenuate light of wavelengths that are not

[0190] The light reflected by the reflective electrode and returned (first reflected light) is semi-transmitted from the light emitting layer. The light that is directly incident on the semi-reflective electrode (first incident light) interferes greatly with the reflective electrode. The optical path length of the light-emitting layer is (2n-1)λ / 4 (where n is a natural number greater than or equal to 1, and λ is the amplified It is preferable to adjust the optical distance to a wavelength that is suitable for the first emission. By matching the phase of the reflected light with that of the first incident light, the light emitted from the light-emitting layer can be amplified. do.

[0191] In the above configuration, even if the EL layer has a plurality of light-emitting layers, a single light-emitting For example, the above-mentioned tandem light-emitting device may be combined with the above-mentioned structure. In addition, multiple EL layers are provided in one light-emitting device with a charge generating layer sandwiched between them, and each EL The layer may be formed with one or more light-emitting layers.

[0192] The microcavity structure makes it possible to enhance the emission intensity of a specific wavelength in the forward direction. This allows for low power consumption. In the case of a light-emitting device that displays images using a single pixel, the yellow light emission not only improves brightness, but also Since a microcavity structure that matches the wavelength of each color can be applied, it is possible to produce light-emitting devices with excellent characteristics. It can be placed.

[0193] The light emitting device of the present embodiment is the same as the light emitting device of the first and second embodiments. Since the semiconductor device uses the same material, it is possible to obtain a light-emitting device with excellent characteristics. The light emitting devices according to the first and second embodiments have a long life. Therefore, the light emitting device can have good reliability. Since the light emitting device using the light emitting device described in 2 has a good light emitting efficiency, it is a light emitting device with low power consumption. It may be an optical device.

[0194] So far, we have explained about active matrix type light emitting devices. From now on, we will discuss passive type light emitting devices. A passive matrix type light emitting device will be described. 7A is a perspective view showing the light-emitting device, and FIG. FIG. 7B is a cross-sectional view taken along the line XY of FIG. 7A. In FIG. 7, the substrate 951 has: An EL layer 955 is provided between the electrode 952 and the electrode 956. It is covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The side walls of the partition layer 954 become thinner between one side wall and the other side wall as they approach the substrate surface. In other words, the cross section of the partition layer 954 in the short side direction is The bottom side (the side that faces the same direction as the surface direction of the insulating layer 953 and is in contact with the insulating layer 953) ) is the upper side (the side that faces in the same direction as the surface direction of the insulating layer 953 and does not contact the insulating layer 953). In this way, by providing the partition layer 954, the light emitting device caused by static electricity or the like can be prevented from being damaged. In addition, the present invention can be applied to a passive matrix type light emitting device. The light emitting device according to the first embodiment and the second embodiment is used, and the light emitting device has high reliability. It is possible to provide a light emitting device with low power consumption.

[0195] The light emitting device described above is a device that includes a large number of minute light emitting devices arranged in a matrix. Since it is possible to control each of these, it can be suitably used as a display device for displaying images. It is a light-emitting device.

[0196] This embodiment mode can be freely combined with other embodiment modes.

[0197] (Embodiment 4) In this embodiment, the light-emitting device according to any one of the first and second embodiments is used as a lighting device. An example of using the lighting device as a lighting device will be described with reference to FIG. 8. FIG. 8(B) is a top view of the lighting device, and FIG. ) is a cross-sectional view taken along line ef in FIG. 8(B).

[0198] The lighting device in this embodiment has an anode 4 on a light-transmitting substrate 400 serving as a support. The anode 401 corresponds to the anode 101 in the second embodiment. When light is extracted from the anode 401 side, the anode 401 is formed from a light-transmitting material.

[0199] A pad 412 for supplying a voltage to the cathode 404 is formed on the substrate 400 .

[0200] An EL layer 403 is formed on the anode 401. The EL layer 403 is the same as that in the first embodiment and the second embodiment. The configuration of the EL layer 103 in the second embodiment, or the light-emitting units 511, 512 and the charge generation This corresponds to a configuration in which the layer 513 is combined. For details of these configurations, refer to the relevant description. I want to be.

[0201] A cathode 404 is formed to cover the EL layer 403. The cathode 404 is the same as the cathode 1 in the second embodiment. When light is emitted from the anode 401 side, the cathode 404 is made of a material with high reflectivity. The cathode 404 is connected to a pad 412, which supplies a voltage to the cathode 404. can be.

[0202] As described above, the light-emitting device having the anode 401, the EL layer 403, and the cathode 404 is The lighting device has a high light emitting efficiency. Therefore, the lighting device in this embodiment can be a lighting device with low power consumption.

[0203] The substrate 400 on which the light emitting device having the above-mentioned configuration is formed is sealed with a sealing substrate 407. The lighting device is completed by fixing and sealing using sealing materials 405 and 406. Either one of 405 and 406 may be used. Also, the inner seal material 406 (FIG. 8(B) ) (not shown) can also be mixed with a desiccant, which can absorb moisture. This leads to improved reliability.

[0204] In addition, a part of the pad 412 and the anode 401 is extended outside the sealing materials 405 and 406. By doing so, it can be used as an external input terminal. An IC chip 420 or the like may be provided.

[0205] As described above, the lighting device according to the present embodiment has the EL element according to the first and second embodiments. The light emitting device described above is used to provide a light emitting device with good reliability. A light emitting device with low power consumption can be provided.

[0206] (Embodiment 5) In this embodiment, the light emitting device according to the first and second embodiments is used as a part of the light emitting device. An example of an electronic device including the light-emitting device according to the first embodiment and the second embodiment will be described. The device has a long life and is a highly reliable light-emitting device. The electronic device described in the above can be an electronic device having a light emitting section with good reliability.

[0207] As an example of an electronic device to which the light-emitting device is applied, a television set (television, (also called television receivers), computer monitors, digital cameras, digital digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices) (hereinafter referred to as "computer games"), portable game machines, personal digital assistants, audio playback devices, large game machines such as pachinko machines Specific examples of these electronic devices are shown below.

[0208] FIG. 9A shows an example of a television device. The television device includes a housing 710. A display unit 7103 is built into the display unit 1. Also, in this embodiment, a stand 7105 is used to support the display unit 1. The display unit 7103 can display images. The display portion 7103 can display the light-emitting device described in Embodiments 1 and 2. The electrodes are arranged in a matrix.

[0209] The television device can be operated using an operation switch provided on the housing 7101 or a separate remote control. The remote control device 7110 includes an operation key 7109. This allows you to control the channel and volume, and the image displayed on the display unit 7103 In addition, the remote control operation device 7110 can be operated. A display portion 7107 for displaying information output from the image forming apparatus may be provided.

[0210] The television set is assumed to be equipped with a receiver and a modem. It can receive television broadcasts and can also communicate by wire or wirelessly via a modem. By connecting to a network, communication can be one-way (sender to receiver) or two-way (sender to It is also possible to communicate information between the sender and the recipient, or between the recipients themselves.

[0211] FIG. 9(B1) shows a computer, which includes a main body 7201, a housing 7202, a display unit 7203, and a keyboard. keyboard 7204, external connection port 7205, pointing device 7206, etc. In addition, the computer is configured to read the light-emitting device according to the first and second embodiments. The display portion 7203 is fabricated by arranging the liquid crystal display panels in a matrix. The computer may be in the form shown in FIG. 9(B2). The second display unit 7206 is used instead of the keyboard 7204 and the pointing device 7206. The second display unit 7210 is a touch panel type. The input display on the display unit 7210 is operated with a finger or a special pen to input data. In addition, the second display portion 7210 can be used not only for input display but also for other displays. The display unit 7203 may also be a touch panel. The two screens are connected by a hinge, which prevents the screen from being scratched when storing or transporting the device. This can also prevent problems such as damage to the device.

[0212] FIG. 9C shows an example of a mobile terminal. The mobile phone is built in a housing 7401. In addition to the display unit 7402, the operation buttons 7403, the external connection port 7404, the speaker 740 5, a microphone 7406, etc. The mobile phone is the same as that in the first embodiment and the second embodiment. A display unit 7402 in which the light-emitting devices according to embodiment 2 are arranged in a matrix is ​​provided. is.

[0213] In the mobile terminal shown in FIG. 9C, information is input by touching the display portion 7402 with a finger or the like. In this case, the user can make a call or write an email. An operation such as pressing a key or the like can be performed by touching the display portion 7402 with a finger or the like.

[0214] The screen of the display unit 7402 has three main modes. The first is a display mode that is mainly used for displaying images. The first mode is a display mode, the second is an input mode for inputting information such as characters, and the third mode is a display mode. This is a display + input mode that combines the display mode and the input mode.

[0215] For example, when making a call or composing an e-mail, the display unit 7402 is used to input characters. The main character input mode is to input characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402. I wish.

[0216] In addition, the mobile terminal may include a sensor for detecting the inclination, such as a gyro or an acceleration sensor. By providing a device, the orientation of the mobile terminal (vertical or horizontal) can be determined and the screen display of the display portion 7402 can be displayed. The display can be switched automatically.

[0217] The screen mode can be changed by touching the display portion 7402 or by operating the housing 7401. This is done by operating the button 7403. Also, depending on the type of image displayed on the display unit 7402, For example, the image signal to be displayed on the display unit is a moving image. If it is data, the mode is switched to display mode, and if it is text data, the mode is switched to input mode.

[0218] In the input mode, the optical sensor of the display unit 7402 detects a signal and displays If there is no input by touch operation of the part 7402 for a certain period of time, the screen mode is changed to the input mode. Alternatively, the display mode may be switched from the normal mode to the display mode.

[0219] The display portion 7402 can also function as an image sensor. By touching the palm or fingers of the user on the sensor 02 and capturing an image of the palm print or fingerprint, the user can be authenticated. In addition, a backlight that emits near-infrared light to the display unit or a sensing light that emits near-infrared light By using a source, it is also possible to image finger veins, palm veins, etc.

[0220] Note that the configuration shown in this embodiment mode is a combination of the configurations shown in Embodiment Modes 1 to 4. They can be used in combination.

[0221] As described above, the light emitting device according to the first and second embodiments can be used in the light emitting apparatus. The range of applications is extremely wide, and this light-emitting device can be applied to electronic devices in a wide range of fields. By using the light emitting devices according to the first and second embodiments, the reliability of the light emitting devices is improved. You can get high quality electronic equipment.

[0222] FIG. 10A is a schematic diagram showing an example of a cleaning robot.

[0223] The cleaning robot 5100 has a display 5101 arranged on the top surface and multiple The camera 5102, the brush 5103, and the operation button 5104 are also shown. However, the underside of the cleaning robot 5100 is provided with tires, a suction port, etc. The robot 5100 also has an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezo sensor, It is equipped with various sensors such as a sensor, a light sensor, and a gyro sensor. 100 is equipped with wireless communication means.

[0224] The cleaning robot 5100 moves by itself, detects dirt 5120, and sucks it out from the suction port on its bottom. It can suck up dirt.

[0225] In addition, the cleaning robot 5100 analyzes the image captured by the camera 5102 and detects walls, furniture, or It can detect obstacles such as steps. It can also detect wiring and other obstacles by image analysis. If an object that is likely to get tangled in the brush 5103 is detected, the rotation of the brush 5103 can be stopped. can.

[0226] The display 5101 can display the remaining battery level, the amount of dirt sucked up, etc. The route traveled by the cleaning robot 5100 can be displayed on the display 5101. In addition, the display 5101 may be a touch panel, and the operation buttons 5104 may be a display. It may be provided in the ray 5101.

[0227] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. The images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the Cleaning Robot 5100 can check the state of the room even when he / she is away from home. In addition, the display on the display 5101 can be displayed on a mobile electronic device such as a smartphone. You can also check it out at.

[0228] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0229] The robot 2100 shown in FIG. 10(B) includes a computing device 2110, an illuminance sensor 2101, A microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, It is equipped with a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0230] The microphone 2102 has a function of detecting the user's voice and environmental sounds. The speaker 2104 has a function of emitting sound. The user can communicate with the computer using the computer 2102 and the speaker 2104. It is possible.

[0231] The display 2105 has a function of displaying various information. It is possible for the user to display desired information on the display 2105. The display 2105 may be equipped with a touch panel. The information terminal may be a terminal that can be used for charging and discharging the battery. and enables data transfer.

[0232] The upper camera 2103 and the lower camera 2106 are used to capture images of the surroundings of the robot 2100. The obstacle sensor 2107 detects the obstacles of the robot 210 using the moving mechanism 2108. When the robot 21 moves forward, it can sense the presence or absence of obstacles in its path. 00 uses an upper camera 2103, a lower camera 2106, and an obstacle sensor 2107. The light-emitting device according to one embodiment of the present invention can recognize the surrounding environment and move safely. It can be used for the display 2105.

[0233] FIG. 10C is a diagram showing an example of a goggle-type display. Goggle-type display For example, the device includes a housing 5000, a display unit 5001, a speaker 5003, and an LED lamp 5004. , connection terminal 5006, sensor 5007 (force, displacement, position, speed, acceleration, angular velocity, rotation speed ,distance, light, liquid, magnetic, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, (including functions to measure radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), The microphone 5008, the display unit 5002, the support unit 5012, the earphones 5013, etc. .

[0234] The light-emitting device according to one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002. .

[0235] FIG. 11 shows a configuration of the light-emitting device according to the first and second embodiments, which is a lighting device. The desk lamp shown in FIG. 11 is an example of a desk lamp using the same. 02, and the lighting device described in the third embodiment may be used as the light source 2002.

[0236] FIG. 12 shows a configuration of the light-emitting device according to the first and second embodiments, which is installed in a lighting device 3 in a room. 001. The light-emitting devices described in the first and second embodiments are Since the light emitting device is highly reliable, it can be used as a highly reliable lighting device. Since the light-emitting devices described in the first and second embodiments can be made large in area, It can be used as a large-area lighting device. The light-emitting device described is thin and can be used as a thin lighting device. become.

[0237] The light emitting devices according to the first and second embodiments can be used for automobile windshields, The embodiment 1 and the embodiment 2 can be mounted on a flash board. FIG. 1 shows an embodiment in which the light emitting device is used on the windshield or dashboard of an automobile. The display areas 5200 to 5203 are the light-emitting devices described in Embodiments 1 and 2. The display area is provided using a device.

[0238] In this embodiment, the display area 5200 and the display area 5201 are provided on the windshield of a car. A display device incorporating the light-emitting device according to the first and second embodiments. In the light-emitting device described in the second embodiment, the anode and the cathode are made of light-transmitting electrodes. This allows the display device to be in a see-through state, where the other side can be seen through. Yes, you can. If the display is see-through, even if it is installed on the windshield of a car, It can be installed without obstructing the view. When a transistor is provided, an organic transistor made of an organic semiconductor material or a transistor made of an oxide semiconductor is used. A light-transmitting transistor such as a transistor having a light-transmitting property is preferably used.

[0239] The display area 5202 is a display device according to the first and second embodiments provided in a pillar portion. The display device is equipped with an optical device. The display area 5202 includes an imaging device provided on the vehicle body. By projecting images from the steps, it is possible to compensate for the view obstructed by the pillars. Similarly, the display area 5203 provided on the dashboard is not blocked by the vehicle body. By projecting images from an imaging device installed on the outside of the vehicle, the driver can see the blind spots. This can enhance safety by projecting images to complement the invisible parts. This allows the driver to check for safety more naturally and without any discomfort.

[0240] The display area 5203 also displays navigation information, speedometer, tachometer, odometer, fuel gauge, gear It can provide a variety of other information by displaying the status, air conditioning settings, etc. The display items and layout can be changed as needed to suit the user's preferences. This information can also be provided in the display areas 5200 to 5202. The display areas 5200 to 5203 can also be used as lighting devices. .

[0241] 14(A) and (B) show a foldable mobile information terminal 5150. The foldable mobile information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 515. FIG. 14(A) shows the portable information terminal 5150 in an unfolded state. Fig. 5B) shows the portable information terminal in a folded state. The portable information terminal 5150 has a large display area. Despite having a range of 5152, it folds up compactly and is highly portable.

[0242] The display area 5152 can be folded in half by the bend 5153. 3 is composed of an expandable member and multiple support members, and when folding, the expandable The member is stretched, and the bent portion 5153 has a radius of curvature of 2 mm or more, preferably 3 mm or more. It can be folded.

[0243] The display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). The light-emitting device according to one embodiment of the present invention can be used in the display region 5152. Cut.

[0244] 15(A) to (C) show a foldable portable information terminal 9310. FIG. 15(A) shows a portable information terminal 9310 in an unfolded state. FIG. 15(B) shows a portable information terminal 9310 in an unfolded state or A portable information terminal 9310 is shown in a folded state changing from one to the other. FIG. 15C shows the portable information terminal 9310 in a folded state. The foldable design is highly portable and unfolds for a seamless, large viewing area. This provides excellent visibility of the display.

[0245] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. The display panel 9311 is a touch panel equipped with a touch sensor (input device). The display panel 9311 may be a display panel (input / output device). The portable information terminal 9310 is in an unfolded state by bending the two housings 9315. The light-emitting device according to one embodiment of the present invention can be reversibly transformed from a folded state to a folded state. It can be used for the display panel 9311. EXAMPLES

[0246] In this example, a light-emitting device 1 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0247] [ka]

[0248] (Method of manufacturing light-emitting device 1) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was set to 70 nm, and the electrode area was 2 The dimensions were 2 mm x 2 mm.

[0249] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0250] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa, and vacuum deposition is performed. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0251] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10n A hole injection layer 111 was formed by co-evaporation.

[0252] Next, on the hole injection layer 111, BBABnf was deposited at 20 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 10 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0253] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-1-propanol represented by the above structural formula (iii) αN-βNPAnth) and (iv) 3,10-Bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenyl Amino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA 2Nbf(IV)-02) in a weight ratio of 1:0.015 (=αN-βNPAnth:3, 10PCA2Nbf(IV)-02) was co-evaporated to form the light-emitting layer 113 at 25 nm. Successful.

[0254] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with ZADN in a weight ratio of 1:0.9 (=ZADN:Liq) An electron transport layer 114 was formed by co-evaporation to a thickness of 5 nm.

[0255] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 1 of this example.

[0256] The element structure of the light-emitting device 1 is summarized in the table below.

[0257] [Table 1]

[0258] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0259] [Table 2]

[0260] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element to seal it) After performing UV treatment at 40°C for 1 hour and heat treatment at 80°C for 1 hour, the initial characteristics and The reliability was measured at room temperature.

[0261] The luminance vs. current density characteristics of the light-emitting device 1 are shown in FIG. 16, the current efficiency vs. luminance characteristics in FIG. 17, and the luminance The -voltage characteristics are shown in Fig. 18, the current-voltage characteristics in Fig. 19, and the external quantum efficiency-luminance characteristics in Fig. 20. The emission spectrum is shown in FIG. 2 Nearby The main characteristics of the material are shown in Table 3.

[0262] [Table 3]

[0263] 16 to 21 and Table 3, the light-emitting device 1 according to one embodiment of the present invention has excellent characteristics. It was found to be a blue light-emitting device.

[0264] In addition, the current density is 50mA / cm 2 The graph shows the change in brightness with respect to the operating time. As shown in FIG. 22, a light-emitting device 1 according to one embodiment of the present invention is Even after 600 hours, the brightness remained at about 90% of the initial brightness. It was found that the decrease in luminance due to heating was particularly small, and that the light-emitting device had an extremely long life.

[0265] The degradation curve for light-emitting device 1 shows that the luminance first decreased and then increased. In other words, the deterioration curve has a maximum point. As a result, the light emitting device 1 has a very long life. EXAMPLES

[0266] In this example, a light-emitting device 2 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0267] [ka]

[0268] (Method of manufacturing light-emitting device 2) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was set to 70 nm, and the electrode area was 2 The dimensions were 2 mm x 2 mm.

[0269] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0270] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0271] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10n A hole injection layer 111 was formed by co-evaporation.

[0272] Next, on the hole injection layer 111, BBABnf was deposited at 20 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 10 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0273] Next, 7-[4-(10-phenyl-9-anthryl)phenyl]-2-(4-phenyl-2-(10-phenyl) ... )phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) and ( viii) represented by N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenyl 1,6BnfAP rn-03) in a weight ratio of 1:0.03 (=cgDBCzPA:1,6BnfAPrn- 03), a luminescent layer 113 was formed to a thickness of 25 nm by co-evaporation.

[0274] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with 25n to make a weight ratio of 1:1 (=ZADN:Liq). The electron transport layer 114 was formed by co-evaporation.

[0275] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 2 of this example.

[0276] The element structure of the light-emitting device 2 is summarized in the table below.

[0277] [Table 4]

[0278] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0279] [Table 5]

[0280] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element to seal it) After performing UV treatment at 40°C for 1 hour and heat treatment at 80°C for 1 hour, the initial characteristics and The reliability was measured at room temperature.

[0281] The luminance vs. current density characteristics of the light-emitting device 2 are shown in FIG. 23, the current efficiency vs. luminance characteristics in FIG. 24, and the luminance The -voltage characteristics are shown in Fig. 25, the current-voltage characteristics in Fig. 26, and the external quantum efficiency-luminance characteristics in Fig. 27. The emission spectrum is shown in FIG. 2 Nearby The main characteristics of the

[0282] [Table 6]

[0283] 23 to 28 and Table 6, the light-emitting device 2 according to one embodiment of the present invention has excellent characteristics. It was found to be a blue light-emitting device.

[0284] In addition, the current density is 50mA / cm 2 The graph shows the change in brightness with respect to the operating time. As shown in FIG. 29, a light-emitting device 2 according to one embodiment of the present invention is shown. The brightness of the LEDs remains at 97% or more of the initial brightness even after 300 hours of operation. It was found that the decrease in luminance due to heating was particularly small, and that the light-emitting device had an extremely long life.

[0285] The degradation curve for light-emitting device 2 shows that the luminance first decreased and then increased. It can be seen that there is a maximum value. This deterioration behavior The light emitting device 2 is a light emitting element with an extremely long life span in which initial deterioration is suppressed. EXAMPLES

[0286] In this example, a light-emitting device 3 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0287] [ka]

[0288] (Method of manufacturing light-emitting device 3) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was set to 70 nm, and the electrode area was 2 The dimensions were 2 mm x 2 mm.

[0289] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0290] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0291] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10n A hole injection layer 111 was formed by co-evaporation.

[0292] Next, on the hole injection layer 111, BBABnf was deposited at 20 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 10 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0293] Next, 7-[4-(10-phenyl-9-anthryl)phenyl]-2-(4-phenyl-2-(10-phenyl) ... )phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) and ( iv) 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl] )-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation :3,10PCA2Nbf(IV)-02) in a weight ratio of 1:0.015 (=cgDBC zPA:3,10PCA2Nbf(IV)-02) was co-evaporated at 25 nm to emit light. A layer 113 was formed.

[0294] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with 25n to make a weight ratio of 1:1 (=ZADN:Liq). The electron transport layer 114 was formed by co-evaporation.

[0295] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 3 of this example.

[0296] The element structure of the light-emitting device 3 is summarized in the table below.

[0297] [Table 7]

[0298] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0299] [Table 8]

[0300] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element to seal it) After performing UV treatment at 40°C for 1 hour and heat treatment at 80°C for 1 hour, the initial characteristics and The reliability was measured at room temperature.

[0301] The luminance vs. current density characteristics of the light-emitting device 3 are shown in FIG. 30, the current efficiency vs. luminance characteristics in FIG. 31, and the luminance The -voltage characteristics are shown in Fig. 32, the current-voltage characteristics in Fig. 33, and the external quantum efficiency-luminance characteristics in Fig. 34. The emission spectrum of the light-emitting device 3 is shown in FIG. 2 Nearby The main characteristics of the

[0302] [Table 9]

[0303] 30 to 35 and Table 9, the light-emitting device 3 according to one embodiment of the present invention has excellent characteristics. It was found to be a blue light-emitting device.

[0304] In addition, the current density is 50mA / cm 2 The graph shows the change in brightness with respect to the operating time. As shown in FIG. 36, light-emitting device 3, which is a light-emitting device according to one embodiment of the present invention, The brightness of the LEDs remains at 94% or more of the initial brightness even after 300 hours of operation. It was found that the decrease in luminance due to heating was particularly small, and that the light-emitting device had an extremely long life.

[0305] The deterioration curve of the light-emitting device 3 shows that the luminance increases in the early stage and reaches a maximum. This degradation behavior is the cause of the The device 3 is a light-emitting device with an extremely long life span and with suppressed initial deterioration. EXAMPLES

[0306] In this example, a light-emitting device 4 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0307] [ka]

[0308] (Method of manufacturing light-emitting device 4) First, silver (Ag), palladium (Pd), and copper (Cu) were deposited on a glass substrate as a reflective electrode. The alloy film (Ag-Pd-Cu (APC) film) was deposited to a thickness of 100 nm by sputtering. After forming a thick film, indium tin oxide containing silicon oxide (ITSO) was sputtered as a transparent electrode. The anode 101 was formed to a thickness of 85 nm by a galvanic deposition method. The area is 4 mm 2 (2mm x 2mm).

[0309] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0310] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa, and vacuum deposition is performed. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0311] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10 A hole injection layer 111 was formed by co-evaporation to a thickness of 1 nm.

[0312] Next, on the hole injection layer 111, BBABnf was deposited at 25 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 10 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0313] Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)-1-propanol represented by the above structural formula (iii) αN-βNPAnth) and (iv) 3,10-Bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenyl Amino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA 2Nbf(IV)-02) in a weight ratio of 1:0.015 (=αN-βNPAnth:3, 10PCA2Nbf(IV)-02) was co-evaporated to form the light-emitting layer 113 at 25 nm. Successful.

[0314] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with 25n to make a weight ratio of 1:1 (=ZADN:Liq). The electron transport layer 114 was formed by co-evaporation.

[0315] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 15 is formed, the volume ratio of silver (Ag) and magnesium (Mg) is 1:0.1, and the film thickness is 15n The cathode 102 was formed by vapor deposition so that the thickness of the cathode 102 was m, and the light-emitting device 4 was fabricated. The cathode 102 is a semi-transparent and semi-reflective electrode that has the functions of reflecting light and transmitting light. The light emitting device 4 of this embodiment is a top emission element that extracts light from the cathode 102. In addition, the cathode 102 is provided with 1,3,5-tri(diphenyl)benzene represented by the above structural formula (ix). DBT3P-II) was evaporated to a thickness of 80 nm. This improves extraction efficiency.

[0316] The element structure of the light-emitting device 4 is summarized in the table below.

[0317] [Table 10]

[0318] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0319] [Table 11]

[0320] This light-emitting device was placed in a glove box with a nitrogen atmosphere, and the light-emitting device was exposed to the atmosphere. The process of sealing with a glass substrate to prevent exposure (sealing material is applied around the element to seal it) After performing UV treatment at 40°C for 1 hour and heat treatment at 80°C for 1 hour, the initial characteristics and signal The reliability of the material was measured at room temperature.

[0321] The luminance vs. current density characteristics of the light-emitting device 4 are shown in FIG. 42, the current efficiency vs. luminance characteristics in FIG. 43, and the luminance The -voltage characteristics are shown in Figure 44, the current-voltage characteristics in Figure 45, and the external quantum efficiency-luminance characteristics in Figure 46. The emission spectrum is shown in FIG. 2 Nearby The main characteristics of the

[0322] [Table 12]

[0323] 42 to 47 and Table 12, the light-emitting device 4 according to one embodiment of the present invention has excellent characteristics. It was found to be a blue light-emitting device.

[0324] In addition, the initial brightness is 1300cd / m 2 With the current density constant, A graph showing the change in luminance with the change in the luminance is shown in FIG. 48. As shown in FIG. 48, the present invention The light-emitting device 4, which is an optical device, showed approximately 95% of its initial brightness even after 1000 hours. The brightness is maintained, and the decrease in brightness due to the accumulation of driving time is particularly small, and it is a light source with a very long life. It turned out to be an optical device. EXAMPLES

[0325] In this example, a light-emitting device 5 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0326] [ka]

[0327] (Method of Manufacturing Light-Emitting Device 5) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was set to 70 nm, and the electrode area was 2 The dimensions were 2 mm x 2 mm.

[0328] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0329] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa, and vacuum deposition is performed. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0330] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10n A hole injection layer 111 was formed by co-evaporation.

[0331] Next, on the hole injection layer 111, BBABnf was deposited at 20 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 80 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0332] Next, 9-[(3'-dibenzothiophene-4-yl)biphenyl]-1- ... phenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation :9mDBtBPNfpr) and N-[4-(9-phenyl)- -bis(9,9-dimethyl-9H-fluoro-3-yl)phenyl PCBFF) and the biphenyl represented by the above structural formula (xii) Su[4,6-dimethyl-2-(7-(2-methylpropyl)-2-quinolinyl-κN]furan C](2,4-pentanedionato-κ 2 O,O') Iridium (III) (abbreviation RS003)) in a weight ratio of 0.5:0.5:0.05 (=9mDBtBPNfpr :PCBFF:RS003) was co-evaporated to a thickness of 65 nm to form the light-emitting layer 113.

[0333] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with 20n to make the weight ratio 1:1 (=ZADN:Liq). The electron transport layer 114 was formed by co-evaporation.

[0334] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 5 of this example.

[0335] The element structure of the light-emitting device 5 is summarized in the table below.

[0336] [Table 13]

[0337] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0338] [Table 14]

[0339] The light-emitting device was placed in a nitrogen-atmosphere glove box to prevent it from being exposed to the air. The process of sealing the device with a glass substrate (applying a sealant around the device, and then applying UV treatment during sealing) After heat treatment at 80℃ for 1 hour, the initial characteristics and reliability of the light-emitting device were measured. The measurements were carried out at room temperature.

[0340] The luminance vs. current density characteristics of the light-emitting device 5 are shown in FIG. 49, the current efficiency vs. luminance characteristics in FIG. The -voltage characteristics are shown in Figure 51, the current-voltage characteristics in Figure 52, and the external quantum efficiency-luminance characteristics in Figure 53. The emission spectrum is shown in FIG. 2 Nearby The main characteristics of the

[0341] [Table 15]

[0342] 49 to 54 and Table 15, the light-emitting device 5 according to one embodiment of the present invention has excellent characteristics. It was found to be a useful red light-emitting device.

[0343] In addition, the current density is 75mA / cm 2 A graph showing the change in brightness over time (inferior As shown in FIG. 55, the light-emitting device according to one embodiment of the present invention is a light-emitting device. The optical device 5 maintained 99% or more of its initial brightness even after 100 hours of driving. The decrease in luminance due to the accumulation of operating time is particularly small, making it a light-emitting device with an extremely long lifespan. In addition, the degradation curve of the light-emitting device 5 has a characteristic shape with a maximum value. By showing such degradation behavior, it is possible to make a light-emitting element with a very long life. It is possible. EXAMPLES

[0344] In this example, a light-emitting device 6 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0345] [ka]

[0346] (Method of manufacturing light-emitting device 6) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 4 mm 2 (2mm x 2mm).

[0347] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0348] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0349] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10n A hole injection layer 111 was formed by co-evaporation.

[0350] Next, BBABnf was deposited on the hole injection layer 111 for 15 minutes to form a first hole transport layer 112-1. After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (PCzN2) to a thickness of 40 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0351] Next, 8-(1,1'-biphenyl-4-yl)- 4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2- d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm) and the compound represented by the above structural formula (xiv). The above-mentioned 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP) and [2-(4-methyl-5-phenyl-2-pyridinyl-κN] represented by the following structural formula (xv) )phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium( III) (abbreviation: [Ir(ppy)2(mdppy)]) in a weight ratio of 0.4:0.6: 0.1(=8BP-4mDBtPBfpm:PCCP:[Ir(ppy)2(mdppy )) was co-evaporated to form the light-emitting layer 113 having a thickness of 45 nm.

[0352] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with ZADN in a weight ratio of 1:0.9 (=ZADN:Liq) An electron transport layer 114 was formed by co-evaporation to a thickness of 5 nm.

[0353] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 6 of this example.

[0354] The element structure of the light emitting device 6 is summarized in the table below.

[0355] [Table 16]

[0356] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0357] [Table 17]

[0358] The light-emitting device was placed in a nitrogen-atmosphere glove box to prevent it from being exposed to the air. The process of sealing the device with a glass substrate (applying a sealant around the device, and then applying UV treatment during sealing) After heat treatment at 80℃ for 1 hour, the initial characteristics and reliability of the light-emitting device were measured. The measurements were carried out at room temperature.

[0359] The luminance vs. current density characteristics of the light-emitting device 6 are shown in FIG. 56, the current efficiency vs. luminance characteristics in FIG. 57, and the luminance The -voltage characteristics are shown in Figure 58, the current-voltage characteristics in Figure 59, and the external quantum efficiency-luminance characteristics in Figure 60. The emission spectrum is shown in FIG. 2 Nearby The main characteristics of the

[0360] [Table 18]

[0361] 56 to 61 and Table 18, the light-emitting device 6 according to the embodiment of the present invention has excellent characteristics. It was found to be a green light-emitting device.

[0362] In addition, the current density is 50mA / cm 2 The graph shows the change in brightness with respect to the operating time. As shown in FIG. 62, a light-emitting device 6, which is a light-emitting device according to one embodiment of the present invention, is shown. Even after 200 hours, the brightness remained at 80% or more of the initial brightness, It was found that the decrease in luminance due to heating was particularly small, and that the device had a long life. EXAMPLES

[0363] In this example, a light-emitting device 7 according to one embodiment of the present invention will be described. The structural formula of the organic compound used is shown below.

[0364] [ka]

[0365] (Method of Manufacturing Light-Emitting Device 7) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was set to 70 nm, and the electrode area was 2 The dimensions were 2 mm x 2 mm.

[0366] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0367] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa, and vacuum deposition is performed. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0368] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10n A hole injection layer 111 was formed by co-evaporation.

[0369] Next, on the hole injection layer 111, BBABnf was deposited at 55 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 30 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0370] Next, 9-[(3'-dibenzothiophene-4-yl)biphenyl]-1- ... phenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation :9mDBtBPNfpr) and N-(1,1'-biphenyl) represented by the above structural formula (xvi). phenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl nyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) and Bis{4,6-dimethyl-2-[5-(5-cyano- 2-methylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]fu {2,2,6,6-tetramethyl-3,5-heptanedionato-κ} 2 O, O') Iridium(III) (abbreviation: [Ir(dmdppr-m5CP)2(dpm)] ) in a weight ratio of 0.8:0.2:0.1 (=9mDBtBPNfpr:PCBBiF:[ Ir(dmdppr-m5CP)2(dpm)]) was co-evaporated at 60 nm to emit light. A layer 113 was formed.

[0371] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with ZADN in a weight ratio of 1:0.9 (=ZADN:Liq) An electron transport layer 114 was formed by co-evaporation to a thickness of 5 nm.

[0372] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 7 of this example.

[0373] The element structure of the light emitting device 7 is summarized in the table below.

[0374] [Table 19]

[0375] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0376] [Table 20]

[0377] The light-emitting device was placed in a nitrogen-atmosphere glove box to prevent it from being exposed to the air. The process of sealing the device with a glass substrate (applying a sealant around the device, and then applying UV treatment during sealing) After heat treatment at 80℃ for 1 hour, the initial characteristics and reliability of the light-emitting device were measured. The measurements were carried out at room temperature.

[0378] The luminance vs. current density characteristics of the light-emitting device 7 are shown in FIG. 63, the current efficiency vs. luminance characteristics in FIG. 64, and the luminance The -voltage characteristics are shown in Figure 65, the current-voltage characteristics in Figure 66, and the external quantum efficiency-luminance characteristics in Figure 67. The emission spectrum is shown in FIG. 2 Nearby The main characteristics of the

[0379] [Table 21]

[0380] 63 to 68 and Table 21, the light-emitting device 7 according to one embodiment of the present invention has excellent characteristics. It was found to be a useful red light-emitting device.

[0381] In addition, the current density is 75mA / cm 2 The graph shows the change in brightness with respect to the operating time. As shown in FIG. 69, light-emitting device 7, which is a light-emitting device according to one embodiment of the present invention, The brightness of the LEDs remains at 90% or more of the initial brightness even after 400 hours of operation. It was found that the decrease in luminance due to heating was particularly small, and that the light-emitting device had an extremely long life. EXAMPLES

[0382] In this example, a light-emitting device 8 and a light-emitting device 9 according to one embodiment of the present invention will be described. The structural formulae of the organic compounds used in light-emitting device 8 and light-emitting device 9 are shown below.

[0383] [ka]

[0384] (Method of Making Light-Emitting Device 8) First, indium tin oxide containing silicon oxide (ITSO) was sputtered onto a glass substrate. The anode 101 was formed by a film deposition method. The film thickness was 70 nm and the electrode area was 4 mm 2 (2mm x 2mm).

[0385] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, and then After baking at 00°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0386] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa. After vacuum baking at 170°C for 30 minutes in the heating chamber of the device, the substrate is left for about 30 minutes. Allow to cool.

[0387] Next, the substrate on which the anode 101 is formed is placed in a vacuum so that the surface on which the anode 101 is formed faces downward. The substrate was fixed to a substrate holder installed in the vacuum evaporation apparatus, and evaporation was performed on the anode 101 using resistance heating. The N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) was obtained by the above deposition method. Benzo[b]naphtho[1,2-d]furan-8-amine (BBABnf) and AL D-MP001Q (Bunseki Kobo Co., Ltd., Material serial number: 1S20170124) , 10 A hole injection layer 111 was formed by co-evaporation to a thickness of 1 nm.

[0388] Next, on the hole injection layer 111, BBABnf was deposited at 40 After that, a second hole transport layer 112-2 having a thickness of 1 nm was deposited by vapor deposition of a compound represented by the above structural formula (ii). Represented by 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazone) A hole transport layer 112 is formed by depositing PCzN2 (abbreviation: PCzN2) to a thickness of 20 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0389] Next, 4,6-bis[3-(9H-carbazole) represented by the above structural formula (xviii) -9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm) and the above structural formula (x ix) 8-(dibenzothiophene-4-yl)-4-phenyl-2-(9'- Phenyl-3,3'-bi-9H-carbazol-9-yl)-[1]benzofuro[3,2 -d]pyrimidine (abbreviation: 4Ph-8DBt-2PCCzBfpm) and the above structural formula (x x) represented by 2,8-di-tert-butyl-5,11-bis(4-tert-butyl phenyl)-6,12-diphenyltetracene (abbreviation: TBRb) in a weight ratio of 1.0:0 .1:0.01(=4,6mCzP2Pm:4Ph-8DBt-2PCCzBfpm:T A 40 nm thick light emitting layer 113 was formed by co-evaporation so that the luminescent layer 113 was a 40 nm thick luminescent layer (BRb).

[0390] Thereafter, on the light-emitting layer 113, 2-{4-[9,10-di(naphthalene) phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimide dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviation: Liq) was mixed with 25n to make a weight ratio of 1:1 (=ZADN:Liq). The electron transport layer 114 was formed by co-evaporation.

[0391] After the electron transport layer 114 is formed, Liq is evaporated to a thickness of 1 nm to form an electron injection layer 1 Then, aluminum is evaporated to a thickness of 200 nm to form a cathode. 102 was formed to fabricate the light emitting device 8 of this example.

[0392] (Method of manufacturing light-emitting device 9) The light-emitting device 9 has a first hole transport layer 112-1 formed to a thickness of 30 nm in the light-emitting device 8. The light-emitting device was fabricated in the same manner as in the light-emitting device 8, except that the light-emitting layer 113 was formed without using TBRb. Ta.

[0393] The device structures of light-emitting device 8 and light-emitting device 9 are summarized in the table below.

[0394] [Table 22]

[0395] The 4Ph-8DBt-2PCCzBfpm used in the light-emitting layer exhibits thermally activated delayed fluorescence (T The light-emitting device 8 is a material that exhibits 4Ph-8DBt-2PCCzBfpm. Used as part of the host material, it is an emitter that transfers energy to the fluorescent material TBRb. The light-emitting device 9 has a TADF material 4Ph-8DBt-2 PCCzBfpm itself is a light-emitting device that emits light.

[0396] Here, the HOMO level, LUMO level and electric field strength [ The table below summarizes the electron mobility when the square root of [V / cm] is 600.

[0397] [Table 23]

[0398] The light-emitting device was placed in a nitrogen-atmosphere glove box to prevent it from being exposed to the air. The process of sealing the device with a glass substrate (applying a sealant around the device, and then applying UV treatment during sealing) After heat treatment at 80℃ for 1 hour, the initial characteristics and reliability of the light-emitting device were measured. The measurements were carried out at room temperature.

[0399] The luminance vs. current density characteristics of light-emitting device 8 and light-emitting device 9 are shown in Figure 70. The characteristics are shown in Figure 71, the brightness-voltage characteristics in Figure 72, the current density-voltage characteristics in Figure 73, and the external quantum The efficiency-luminance characteristics are shown in FIG. 74, and the emission spectrum is shown in FIG. and luminous device 9 1000cd / m 2 The main characteristics of the area are shown in Table 24.

[0400] [Table 24]

[0401] 70 to 75 and Table 24, the light-emitting device 8 and the light-emitting device It was found that device 9 is a light-emitting device with good luminous efficiency.

[0402] In addition, the current density is 50mA / cm 2 The graph shows the change in brightness with respect to the operating time. As shown in FIG. 76, light-emitting device 8, which is a light-emitting device according to one embodiment of the present invention, is shown. The light-emitting device 9 is a light-emitting device and a light-emitting material using TADF as a host material. It was found that the light-emitting device used in this manner had a long life.

[0403] <Reference example 1> In this reference example, the HOMO level, LUMO level and electron transfer level of the organic compounds used in each example are A method for calculating the degree of movement will now be described.

[0404] HOMO and LUMO levels are calculated based on cyclic voltammetry (CV) measurements. It is possible.

[0405] The measurement device used was an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model). The solution used in the CV measurements was dehydrated dimethyl ether. Dimethylformamide (DMF) (Aldrich Co., Ltd., 99.8%, Catalog No. 227 05-6) was used as the supporting electrolyte, tetra-n-butylammonium perchlorate (nB u4NClO4) (Tokyo Chemical Industry Co., Ltd., catalog number: T0836) was added at 100 mmol / The measurement target was then dissolved in water to a concentration of 2 mmol / L. The working electrode was a platinum electrode (PT E platinum electrode) as an auxiliary electrode, and a platinum electrode (B.A.S. Co., Ltd., VC-3 P The counter electrode (5 cm) was used as the reference electrode, and the Ag / Ag+ electrode (B.A.E. The measurements were performed at room temperature (20 to 32°C). The scan speed during CV measurement was standardized to 0.1 V / sec. The oxidation potential Ea [V] and reduction potential Ec [V] of the reference electrode were measured. The intermediate potential of the reduction wave was set as Ec, and the intermediate potential of the reduction-oxidation wave was set as Ec. The potential energy of the reference electrode with respect to the vacuum level is -4.94 eV. Since it is known that the HOMO level [eV] = -4.94-Ea, the LUMO level [eV ]=-4.94-Ec. Calculate the HOMO and LUMO levels. It is possible.

[0406] Electron mobility was measured by impedance spectroscopy (Impedance Spectroscopy: It can be measured using the IS method.

[0407] The carrier mobility of EL materials is measured by the transient photocurrent method (Time-of-flight:T OF method and space-charge-limited current The method of calculating the capacitance from the IV characteristics of the SCLC (nt:SCLC method) has been known for a long time. The TOF method requires a sample with a thickness much thicker than that of an actual organic EL element. The LC method has the disadvantage that the dependence of carrier mobility on electric field strength cannot be obtained. The thickness of the organic film required for the measurement is thin, at only a few hundred nm, so even a relatively small amount of EL material is sufficient. It is possible to form a film, and the mobility can be measured with a film thickness close to that of an actual EL element. and the electric field strength dependence of carrier mobility can also be obtained.

[0408] In the IS method, a small sinusoidal voltage signal (V = V0 [exp(jωt)]) is applied to the EL element, The amplitude of the response current signal (I = I0exp[j(ωt+φ)]) and its phase with the input signal The impedance of the EL element (Z=V / I) is calculated from the difference. If the applied voltage is varied from 0.01 to 0.1 V, the impedance will vary with the relaxation time. The components can be separated and measured.

[0409] Here, the admittance Y (= 1 / Z), which is the reciprocal of the impedance, is given by the following formula (1): It can be expressed as conductance G and susceptance B as shown below.

[0410]

number

[0411] Furthermore, by using the single charge injection model, The following equations (2) and (3) can be calculated: where g (equation (4)) is the differential conductance. In the formula, C is the capacitance, θ is the travel angle, and ω represents the angular frequency. t is the transit time. The analysis uses the current equation, Poisson's equation, and current continuity equation. The above equation is used, ignoring the existence of diffusion current and trap levels.

[0412]

number

[0413] The method of calculating the mobility from the frequency characteristics of the capacitance is the -ΔB method. The ωΔG method is a method for calculating the mobility from the frequency characteristics of a carrier.

[0414] In practice, first, an electron-only device is fabricated from the material whose electron mobility is to be determined. A junction element is an element designed to allow only electrons to flow as carriers. In this section, we explain the method for calculating the mobility from the frequency characteristics of the capacitance (-ΔB method). A schematic diagram of a child-only element is shown in FIG.

[0415] The structure of the electron-only element prepared for this measurement is shown in Figure 37. A first layer 210, a second layer 211, and a third layer 212 are disposed between the cathode 202. The material for which the mobility is to be calculated can be used as the material for the second layer 211. Explain the example of measuring the electron mobility of a 1:1 (weight ratio) co-evaporated film of q. Specific configuration examples are summarized in the table below.

[0416] [Table 25]

[0417] The current density of the electron-only device fabricated with a co-evaporated film of ZADN and Liq as the second layer 211 was The power-voltage characteristics are shown in FIG.

[0418] The impedance measurement was performed by applying a DC voltage in the range of 5.0V to 9.0V while applying an AC voltage The measurements were performed under the conditions of a voltage of 70 mV and a frequency of 1 Hz to 3 MHz. The capacitance is calculated from the admittance (equation (1) above), which is the reciprocal of the impedance. The frequency characteristics of the calculated capacitance C at an applied voltage of 7.0 V are shown in FIG.

[0419] The frequency characteristic of capacitance C is the space charge caused by carriers injected by a small voltage signal. This occurs because the load cannot completely follow the minute AC voltage, and a phase difference occurs in the current. Here, the transit time of the carriers in the film is the time T for the injected carriers to reach the counter electrode. It is defined and expressed by the following equation (5).

[0420]

number

[0421] The negative susceptance change (-ΔB) is the capacitance change -ΔC multiplied by the angular frequency ω (-ωΔ C) The lowest frequency peak frequency f' max (=ω max / 2π) and From equation (3), the relationship between the row time T and the row time T can be derived as shown in equation (6) below.

[0422]

number

[0423] The frequency characteristics of -ΔB calculated from the above measurements (i.e., when the DC voltage is 7.0 V) are shown in Fig. 4. 0. The lowest frequency peak frequency f' obtained from Figure 40 max is indicated by the arrow in the figure. did.

[0424] f' obtained from the above measurements and analysis max From this, the travel time T can be calculated (the above formula ( 6)) Using the above formula (5), calculate the electron mobility at a voltage of 7.0 V in this case. Similar measurements were performed at DC voltages ranging from 5.0V to 9.0V. Since the electron mobility at (electric field strength) can be calculated, the dependence of the mobility on the electric field strength can also be measured.

[0425] Using the above calculation method, the final electron mobility of each organic compound was calculated based on the electric field strength. The square root of the electric field strength [V / cm] read from the figure is 600 [V / cm]. 1 / 2 The electron mobility values ​​at these times are shown in Table 10.

[0426] [Table 26]

[0427] In this way, it is possible to calculate the electron mobility. , Takayuki Okachi et al. ”Japanese Journal of Applied Physics” Vol. 47, No. 12, 2008, Please see pp. 8965-8972.

[0428] <Reference example 2> 9mDBtBPNfpr and 8BP-4mDBtPBfpm used in the examples are unpublished. Since these are all substances, the synthesis methods for each will be explained below.

[0429] ≪How to synthesize 9mDBtBPNfpr≫ In Example 1, 9-[(3'-dibenzothiophene-4- (yl)biphenyl-3-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine This article explains how to synthesize 9mDBtBPNfpr. The structure of PNfpr is shown below.

[0430] [ka]

[0431] (Step 1: 6-chloro-3-(2-methoxynaphthalen-1-yl)pyrazine-2- Synthesis of amines First, 4.37 g of 3-bromo-6-chloropyrazine-2-amine and 2-methoxynaphthalene 4.23g of 1-boronic acid, 4.14g of potassium fluoride, 75g of dehydrated tetrahydrofuran The flask was then placed in a three-neck flask equipped with a reflux condenser and the inside of the flask was replaced with nitrogen. After degassing by stirring at 40°C, tris(dibenzylideneacetone)dipalladium(0) ( abbreviation: Pd2(dba)3) 0.57 g, tri-tert-butylphosphine (abbreviation: P 4.5 mL of (tBu)3) was added, and the mixture was stirred at 80° C. for 54 hours to react.

[0432] After a predetermined time had elapsed, the mixture was filtered under suction, and the filtrate was concentrated. The mixture was purified by silica gel column chromatography using ethyl acetate / ethyl acetate 9:1 as a developing solvent. The desired pyrazine derivative was obtained (yellow-white powder, yield 2.19 g, 36%). Step 1 The synthesis scheme is shown below.

[0433] [ka]

[0434] (Step 2: 9-chloronaphtho[1',2':4,5]furo[2,3-b]pyrazine synthesis) Next, 6-chloro-3-(2-methoxynaphthalene-1-yl)piperidinyl obtained in step 1 above was added to the 2.18 g of radin-2-amine, 63 mL of dehydrated tetrahydrofuran, and 84 mL of glacial acetic acid were mixed together in a tritium solution. The flask was cooled to -10°C and then nitrite was added to the flask. 2.8 mL of rt-butyl was added dropwise, and the mixture was stirred at -10°C for 30 minutes and at 0°C for 3 hours. After the time had passed, 250 mL of water was added to the resulting suspension, and the target pyridine was isolated by suction filtration. The compound was obtained as a yellowish white powder (yield: 1.48 g, 77%). The model is shown below.

[0435] [ka]

[0436] (Step 3: 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl] Naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNf pr) synthesis Furthermore, the 9-chloronaphtho[1',2':4,5]furo[2,3- b] Pyrazine 1.48g, 3'-(4-dibenzothiophene)-1,1'-biphenyl- 3.41 g of 3-boronic acid, 8.8 mL of 2 M potassium carbonate aqueous solution, 100 mL of toluene, 10 mL of ethanol was placed in a three-neck flask, and the inside of the flask was replaced with nitrogen. The inside of the flask was stirred under reduced pressure. After degassing by stirring, bis(triphenylphosphine)palladium(II) dichloride was added. Add 0.84 g of Pd(PPh3)2Cl2, stir at 80°C for 18 hours, and react. He responded.

[0437] After a predetermined time had elapsed, the resulting suspension was filtered by suction and washed with water and ethanol. The body was dissolved in toluene and passed through a filter aid consisting of layers of Celite, alumina, and Celite. After filtering, the target product was obtained by recrystallization with a mixed solvent of toluene and hexane. Light yellow solid, yield 2.66 g, 82% yield.

[0438] The resulting pale yellow solid (2.64 g) was purified by train sublimation. The purification conditions were a pressure of 2.6 Pa, argon gas flow rate of 15 mL / min, and 3 The solid was heated at 15°C. After purification by sublimation, the target pale yellow solid was obtained in an amount of 2.34 g and a yield of 89%. The synthesis scheme for step 3 is shown below.

[0439] [ka]

[0440] The pale yellow solid obtained in step 3 was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR The analysis results are shown below. From these results, it was found that 9mDBtBPNfpr was obtained. .

[0441] 1 H-NMR.δ(CD2Cl2):7.47-7.51(m,2H),7.60-7. 69(m,5H),7.79-7.89(m,6H),8.05(d,1H),8.10 -8.11(m,2H),8.18-8.23(m,3H),8.53(s,1H),9 .16(d,1H),9.32(s,1H).

[0442] ≪How to synthesize 8BP-4mDBtPBfpm≫ In the examples, 8-(1,1'-biphenyl-4-yl) 1-(4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3 ,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm) synthesis method is explained. The structure of 8BP-4mDBtPBfpm is shown below.

[0443] [ka]

[0444] (8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophene-4-yl) Synthesis of phenyl-[1]benzofuro[3,2-d]pyrimidine 8-Chloro-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuran 1.37g of 3,2-d pyrimidine, 0.657g of 4-biphenylboronic acid, and phosphoric acid 1.91 g of tripotassium chloride, 30 mL of diglyme, and 0.662 g of t-butanol were placed in a three-neck flask. The contents of the flask were degassed by stirring under reduced pressure and replaced with nitrogen.

[0445] The mixture was heated to 60° C., and 23.3 mg of palladium(II) acetate, di(1-adamantyl) 66.4 mg of (ethyl)-n-butylphosphine was added, and the mixture was stirred at 120° C. for 27 hours. Water was added to the reaction solution, which was then subjected to suction filtration. The residue was washed with water, ethanol, and toluene. The residue was dissolved in hot toluene and packed in the following order: Celite, alumina, and Celite. The resulting solution was concentrated to dryness and recrystallized from toluene to give The target product, a white solid, was obtained in an amount of 1.28 g and a yield of 74%.

[0446] 1.26 g of this white solid was purified by train sublimation. The conditions were a pressure of 2.56 Pa, argon gas flow rate of 10 mL / min, and a temperature of 310 The solid was heated at 50°C. After purification by sublimation, 1.01 g of the target pale yellow solid was obtained with a recovery rate of 80%. The synthesis scheme is shown below.

[0447] [ka]

[0448] The pale yellow solid obtained in the above reaction was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR analysis results The results are shown below. From these results, it was found that 8BP-4mDBtPBfpm was obtained. Ta.

[0449] 1 H-NMR.δ(CDCl3):7.39(t,1H), 7.47-7.53(m,4 H), 7.63-7.67(m,2H), 7.68(d,2H), 7.75(d,2H) , 7.79-7.83(m,4H), 7.87(d,1H), 7.98(d,1H), 8 .02(d,1H), 8.23-8.26(m,2H), 8.57(s,1H), 8.7 3(d,1H), 9.05(s,1H), 9.34(s,1H).

[0450] ≪How to synthesize 4Ph-8DBt-2PCCzBfpm≫ In the examples, 8-(dibenzothiophene-4-yl) -4-phenyl-2-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl )-[1]Benzofuro[3,2-d]pyrimidine (abbreviation: 4Ph-8DBt-2PCCz The synthesis method of 4Ph-8DBt-2PCCzBfpm is explained. is shown below.

[0451] [ka]

[0452] (Step 1; 2,8-dichloro-4-phenyl[1]benzofuro[3,2-d]pyrimidinyl Synthesis of gin 2,4,8-Trichloro[1]benzofuro[3,2-d]pyrimidine 10g (37mmol l), phenylboronic acid 4.5 g (371 mmol), 2 M potassium carbonate aqueous solution 37 mL Put 180 mL of toluene and 18 mL of ethanol into a 500 mL three-neck flask. The inside of the container was degassed and replaced with nitrogen. II) 1.3 g (1.8 mmol) of dichloride was added, and the mixture was stirred at 80° C. for 16 hours.

[0453] After a predetermined time had elapsed, the reaction mixture was concentrated, water was added, and the mixture was filtered under suction. The solid was washed with ethanol to obtain a solid. This solid was dissolved in toluene and The mixture was filtered through a filter material layered in the order of NaCl and Celite. The filtrate was concentrated to obtain the desired product. The product was obtained as a white solid (11 g, 91% yield). The synthesis scheme for step 1 is shown below.

[0454] [ka]

[0455] (Step 2; 8-chloro-4-phenyl-2-(9'-phenyl-3,3'-bi-9H Synthesis of -carbazol-9-yl-[1]benzofuro[3,2-d]pyrimidine 2,8-Dichloro-4-phenyl-[1]benzofuro[3,2-d ]pyrimidine 5.0g (16mmol), 9-phenyl-3,3'-bi-9H-carbazo 6.5g (16mmol), tert-sodium butoxide 3.1g (32mmol) l) 150 mL of xylene was placed in a 300 mL three-neck flask, and the inside of the flask was replaced with nitrogen. Here, di-tert-butyl(1-methyl-2,2-diphenylcyclopropyl)phos Fin (abbreviation: cBRIDP) 224 mg (0.64 mmol), allylpalladium (I I) Add 58 mg (0.16 mmol) of chloride dimer and heat and stir at 90°C for 7 hours. Ta.

[0456] Water was added to the reaction mixture, and the aqueous layer was extracted with toluene. The layers were combined and washed with saturated saline, and the organic layer was dried over anhydrous magnesium sulfate. The mixture was gravity filtered, and the filtrate was concentrated to obtain a solid. The product was purified by chromatography using a 1:1 mixture of toluene and hexane as the developing solvent. The obtained fraction was concentrated to obtain 5.5 g of the target yellow solid. The synthesis scheme for step 2 is shown below.

[0457] [ka]

[0458] (Step 3: Synthesis of 4Ph-8DBt-2PCCzBfpm) 8-Chloro-4-phenyl-2-(9'-phenyl-3,3'- Bis-9H-carbazol-9-yl)[1]benzofuro[3,2-d]pyrimidine 2.2 5g (3.3mmol), 4-dibenzothiopheneboronic acid 0.82g (3.6mmol ), 1.5 g (9.8 mmol) of cesium fluoride, and 35 mL of xylene were placed in a three-neck flask. The atmosphere in the flask was replaced with nitrogen.

[0459] The mixture was heated to 60° C., and tris(dibenzylideneacetone)dipalladium ( 0) 60 mg (0.065 mmol) and 2'-(dicyclohexylphosphino)acetate Add 77 mg (0.2 mmol) of phenone ethylene ketal and heat and stir at 100°C for 16 hours. The mixture was stirred. 30 mg of tris(dibenzylideneacetone)dipalladium(0) was further added. (0.032mmol), 2'-(dicyclohexylphosphino)acetophenone ethyl Add 36 mg (0.1 mmol) of ketal and heat at 110°C for 7 hours and at 120°C for 7 hours. Heat and stir.

[0460] Water was added to the reaction mixture, which was then suction filtered. The filter cake was washed with ethanol. The solution was dissolved in ethylene and filtered through a filter layer consisting of Celite, alumina, and Celite in that order. The filtrate obtained was concentrated and recrystallized from toluene to obtain the target yellow solid in an amount of 1.8 g. The synthesis scheme is shown below.

[0461] [ka]

[0462] The resulting yellow solid (0.90 g) was purified by train sublimation. The production conditions are pressure 1.58×10 -2 The solid was heated at 400°C under a temperature of 100°C. Thereafter, the target product, a yellow solid, was obtained in a yield of 0.78 g and a recovery rate of 86%.

[0463] The yellow solid obtained in the above reaction was analyzed by nuclear magnetic resonance spectroscopy ( 1 H-NMR Analysis Results The results are shown below. From these results, in this synthesis example, 4Ph-8DBt-2PCCzBfpm It was found that the following was obtained.

[0464] 1 H-NMR.δ(CDCl3):7.33(t,1H),7.41-7.53(m,7 H),7.59(t,1H),7.62-7.70(m,7H),7.72-7.75( m,2H),7.83(dd,1H),7.87(dd,1H),7.93-7.95( m,2H),8.17(dd,1H),8.23-8.26(m,4H),8.44(d ,1H),8.52(d,1H),8.75(d,1H),8.2(d,2H),9.0 2(d,1H),9.07(d,1H). [Explanation of symbols]

[0465] 101 Anode 102 Cathode 103 EL layer 111 Hole injection layer 112 Hole transport layer 112-1 First hole transport layer 112-2 Second hole transport layer 113 Light-emitting layer 113-1 Luminous area 114 Electron transport layer 114-1 Non-radiative recombination region 115 Electron injection layer 116 Charge generation layer 117 P type layer 118 Electronic Relay Layer 119 Electron injection buffer layer 201 Anode 202 Cathode 210 First Layer 211 Second Layer 212 Third Layer 400 Substrates 401 Anode 403 EL layer 404 Cathode 405 Sealing material 406 Sealing material 407 Sealing substrate 412 Pad 420 IC chip 501 Anode 502 Cathode 511 First Light Emitting Unit 512 Second Light Emitting Unit 513 Charge generation layer 601 Driver circuit section (source line driver circuit) 602 Pixel section 603 Drive circuit section (gate line drive circuit) 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 Element Substrate 611 Switching FET 612 Current Control FET 613 Anode 614 Insulation 616 EL layer 617 Cathode 618 Light Emitting Devices 951 Board 952 Electrode 953 Insulation Layer 954 Partition layer 955 EL layer 956 Electrode 1001 Board 1002 Undercoat insulating film 1003 Gate insulating film 1006 Gate electrode 1007 Gate electrode 1008 Gate electrode 1020 First interlayer insulating film 1021 Second interlayer insulating film 1022 Electrode 1024W anode 1024R Anode 1024G anode 1024B Anode 1025 Bulkhead 1028 EL layer 1029 Cathode 1031 Sealing substrate 1032 Sealing material 1033 Transparent substrate 1034R Red color layer 1034G Green colored layer 1034B Blue colored layer 1035 Black Matrix 1036 Overcoat layer 1037 Third interlayer insulating film 1040 Pixel section 1041 Drive circuit section 1042 Periphery 2001 Case 2002 light source 2100 Robot 2110 Arithmetic equipment 2101 Illuminance sensor 2102 Microphone 2103 Upper Camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 3001 Lighting equipment 5000 cabinet 5001 Display section 5002 Display section 5003 Speaker 5004 LED Lamp 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning robot 5101 Display 5102 Camera 5103 Brush 5104 Operation button 5150 Portable Information Terminal 5151 Case 5152 Display area 5153 Bend 5120 Garbage 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 Case 7103 Display section 7105 Stand 7107 Display section 7109 Operation key 7110 Remote control device 7201 Main unit 7202 Case 7203 Display section 7204 Keyboard 7205 External connection port 7206 Pointing Device 7210 Second display unit 7401 Case 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Mike 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 Case

Claims

1. A light-emitting device comprising a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer, the first layer is located between the first electrode and the second layer; the second layer is located between the first layer and the light-emitting layer; the light-emitting layer is located between the second layer and the second electrode; the first layer comprises a first organic compound; the second layer comprises a second organic compound; the second organic compound has at least one of a carbazole skeleton, a dibenzothiophene skeleton, and an anthracene skeleton, a difference between a HOMO level of the first organic compound and a HOMO level of the second organic compound is within 0.2 eV; A light emitting device, wherein the HOMO level of the second organic compound is deeper than the HOMO level of the first organic compound.

2. A light-emitting device comprising a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer, the first layer is located between the first electrode and the second layer; the second layer is located between the first layer and the light-emitting layer; the light-emitting layer is located between the second layer and the second electrode; the first layer comprises a first organic compound; the second layer comprises a second organic compound; the first organic compound has at least one of a carbazole skeleton, a dibenzothiophene skeleton, and an anthracene skeleton, the second organic compound has at least one of a carbazole skeleton, a dibenzothiophene skeleton, and an anthracene skeleton, a difference between a HOMO level of the first organic compound and a HOMO level of the second organic compound is within 0.2 eV; A light emitting device, wherein the HOMO level of the second organic compound is deeper than the HOMO level of the first organic compound.

3. A light-emitting device comprising a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer, the first layer is located between the first electrode and the second layer; the second layer is located between the first layer and the light-emitting layer; the light-emitting layer is located between the second layer and the second electrode; the first layer comprises a first organic compound; the second layer comprises a second organic compound; the first organic compound has a carbazole skeleton, the second organic compound has at least one of a carbazole skeleton, a dibenzothiophene skeleton, and an anthracene skeleton, a difference between a HOMO level of the first organic compound and a HOMO level of the second organic compound is within 0.2 eV; A light emitting device, wherein the HOMO level of the second organic compound is deeper than the HOMO level of the first organic compound.

4. A light-emitting device comprising a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer, the first layer is located between the first electrode and the second layer; the second layer is located between the first layer and the light-emitting layer; the light-emitting layer is located between the second layer and the second electrode; the first layer comprises a first organic compound; the second layer comprises a second organic compound; the first organic compound has a carbazole skeleton, the second organic compound has a carbazole skeleton, a difference between a HOMO level of the first organic compound and a HOMO level of the second organic compound is within 0.2 eV; A light emitting device, wherein the HOMO level of the second organic compound is deeper than the HOMO level of the first organic compound.

5. In any one of claims 1 to 4, A third layer, the third layer is provided between the light emitting layer and the second electrode, the third layer includes a third organic compound and a fourth organic compound; The fourth organic compound is an alkali metal organic complex or an alkaline earth metal organic complex.

6. In claim 5, A light-emitting device having an electron mobility of 1×10 −7 cm 2 / Vs or more and 5×10 −5 cm 2 / Vs or less when the square root of an electric field strength [V / cm] is 600, as measured using a thin film of the third organic compound.

7. In claim 5, A light-emitting device having an electron mobility of 1×10 −7 cm 2 / Vs or more and 5×10 −5 cm 2 / Vs or less when the square root of the electric field strength [V / cm] is 600, as measured using a co-evaporated film of the third organic compound and the fourth organic compound.

8. A light-emitting device comprising: the light-emitting device according to claim 1; and a transistor having an oxide semiconductor.

9. A lighting device having a light-emitting device described in any one of claims 1 to 7 and a housing.

Images