Light-emitting devices

Abstract

Provided is a novel light-emitting device. Alternatively, provided is a light-emitting device with excellent light emission efficiency. Alternatively, provided is a light-emitting device with excellent lifetime. Alternatively, provided is a light-emitting devic e with low driving voltage. 【Solution】A light-emitting device wherein an EL layer has, in order from the anode side, a first layer, a second layer, a third layer, a light-emitting layer , and a fourth layer, the first layer includes a first organic compound and a second organic compound , the fourth layer includes a seventh organic compound, the first organic compound has electron accepting property with respect to the second organic compound, and the HOMO level of the second organic compound is -5.7 eV or higher and -5 .4 eV or lower, and the fourth layer has, in the thickness direction thereof, a portion having a large content of the seventh organic compound and a portion having a small content of the seventh organic compound is provided. ​

Description

[Technical Field]

[0001] One aspect of the present invention is a light-emitting element, a light-emitting device, a display module, and a lighting module. The present invention relates to display devices, light-emitting devices, electronic devices, and lighting devices. One aspect of the present invention is as described above. The technical field of one aspect of the invention disclosed herein is not limited to the technical field of products, methods. , or relating to a manufacturing method. Or, one aspect of the present invention relates to a process, machine This relates to the manufacture or composition of matter. There is. Therefore, more specifically, one aspect of the technical field of the present invention disclosed herein is: Semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, energy storage devices, memory devices, imaging devices Examples include devices, methods for driving them, or methods for manufacturing them. . [Background technology]

[0002] Electroluminescence (EL) using organic compounds The practical application of light-emitting devices (organic EL elements) that utilize ence is progressing. The basic configuration of the device involves sandwiching an organic compound layer (EL layer) containing a light-emitting material between a pair of electrodes. That is the case. A voltage is applied to this device to inject a carrier, and the carrier is re-energized. By utilizing the binding energy, it is possible to obtain light emission from a light-emitting material.

[0003] Since such light-emitting devices are self-emissive, when used as pixels in a display, they become liquid crystals. Compared to other types, it has advantages such as higher visibility and the elimination of the need for a backlight, and flat panel displays It is suitable as a spray element. Furthermore, a display using such a light-emitting device is Furthermore, the ability to manufacture it in a thin and lightweight form is a major advantage. In addition, its extremely fast response speed is also a significant feature. It is one of the signs.

[0004] Furthermore, these light-emitting devices allow for the continuous formation of a light-emitting layer in two dimensions. This allows for the emission of light in a planar manner. This is different from point light sources such as incandescent bulbs and LEDs, This is a characteristic that is difficult to obtain with linear light sources such as fluorescent lamps, and therefore it is a surface light source that can be applied to lighting and the like. It also has high utility value.

[0005] Displays and lighting devices using light-emitting devices in this manner are applicable to a wide range of electronic devices. While suitable, research and development are underway to find light-emitting devices with better efficiency and lifespan. Yes, they are.

[0006] Patent Document 1 describes a first hole transport layer in contact with a hole injection layer and a light-emitting layer, with the first hole injection layer between them. Hole transport with a HOMO level between the HOMO level of the intrusion layer and the HOMO level of the host material. A configuration for providing materials is disclosed.

[0007] The characteristics of light-emitting devices have improved remarkably, including efficiency, durability, and all other characteristics. It must be said that it is still insufficient to meet the high demands for it. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] International Publication No. 2011 / 065136 Pamphlet [Overview of the project] [Problems that the invention aims to solve]

[0009] Therefore, one aspect of the present invention aims to provide a novel light-emitting device. Or, The objective is to provide a light-emitting device with good luminescence efficiency, or a light-emitting device with a good lifespan. The objective is to provide a device, or to provide a light-emitting device with a low drive voltage. The purpose is to achieve this.

[0010] Alternatively, in another aspect of the present invention, a highly reliable light-emitting device, electronic device, and display device are provided, respectively. The purpose is to provide. Alternatively, in another aspect of the present invention, a light-emitting device with low power consumption. The purpose is to provide a device, electronic equipment, and display device, respectively.

[0011] The present invention only needs to solve one of the above-mentioned problems. [Means for solving the problem]

[0012] One aspect of the present invention comprises an anode, a cathode, and an EL layer located between the anode and the cathode. Furthermore, in a light-emitting device in which the EL layer has a light-emitting layer and an electron transport layer, the electron transport layer is The material comprises a first substance and a second substance, wherein the first substance is an alkali metal or alkaline earth metal. The second substance is either an element of the genus, an organic complex, or a compound, and the second substance has electron transport properties. The organic compound, and the electron transport layer has a certain amount of the first substance in the thickness direction. It has a portion with a small amount and a portion with a large amount of the first substance, and the amount of the first substance The portion with a higher amount of the first substance is located closer to the light-emitting layer than the portion with a lower amount. The degradation curve is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device. This is a light-emitting device that has a maximum value.

[0013] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, wherein the EL layer has a light-emitting layer and an electron transport layer, The electron transport layer comprises a first material and a second material, wherein the first material is an alkali metal or The second substance is either an element, organic complex, or compound of a rutile earth metal, and the second substance is electron An organic compound having transport properties, wherein the electron transport layer is the second material in the thickness direction The substance has a portion with a high abundance of the substance and a portion with a low abundance of the second substance, and the second substance There is a region on the light-emitting layer side where the amount of the second substance is less than the region where the amount of the second substance is greater. , the degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device. This is a light-emitting device where the line has a maximum value.

[0014] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. The first layer has a first organic compound and a second organic compound, and the second layer has a first organic compound. The third layer has three organic compounds, the third layer has a fourth organic compound, and the light-emitting layer has a fifth organic compound. The fourth layer has an organic compound and a sixth organic compound, and the fourth layer has a seventh organic compound and a first substance The first organic compound has properties and the second organic compound exhibits electron-accepting ability. The first substance is an alkali metal, the fifth organic compound is a luminescent central substance, and the first substance is an alkali metal or an alkaline earth metal element, organic complex, or compound, and the second is The HOMO level of the organic compound is between -5.7 eV and -5.4 eV, and the seventh organic compound The compound has an electron mobility of 1 × 10⁻¹⁰ at an electric field strength [V / cm] square root of 600. -7 cm 2 / Vs or more 5×10 -5 cm 2 The material is less than or equal to / Vs, and the fourth layer has a thickness direction In the region where the amount of the seventh organic compound is high, the amount of the seventh organic compound It has a portion with less of the seventh organic compound, and is located on the side of the light-emitting layer that is greater than the portion with a greater amount of the seventh organic compound. There are regions where the amount of the seventh organic compound is small, and a constant current is passed through the light-emitting device. The light-emitting device is one in which the degradation curve, represented by the change in the brightness of the light emitted when this occurs, has a maximum value. ru.

[0015] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. Furthermore, the fourth layer is in contact with the light-emitting layer, and the first layer is a first organic compound and The second layer has two organic compounds, and the third layer has a third organic compound, The luminescent layer has four organic compounds, and the luminescent layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance, and the first organic compound is the same The second organic compound is an organic compound that exhibits electron-acceptance, and the fifth organic compound is a luminescent center The first substance is an alkali metal or alkaline earth metal in elemental form, or an organic complex. The first is a compound, and the HOMO level of the second organic compound is -5.7 eV or higher. The electric field strength is -5.4 eV or less, and the seventh organic compound has a square root of 6 electric field strength [V / cm]. The electron mobility at 00 is 1 × 10⁻⁶ -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less The substance is such that the HOMO level of the seventh organic compound is -6.0 eV or higher, and Layer 4 has a portion in its thickness direction where the amount of the 7th organic compound is high, and the 7th It has a portion where the amount of the organic compound is small, and a portion where the amount of the seventh organic compound is large. Furthermore, there is a region on the light-emitting layer side where the amount of the seventh organic compound is small, and the light-emitting device The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the chair, has a maximum value. It is a light-emitting device.

[0016] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. Furthermore, the fourth layer is in contact with the light-emitting layer, and the first layer is a first organic compound and The second layer has two organic compounds, and the third layer has a third organic compound, The luminescent layer has four organic compounds, and the luminescent layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance, and the first organic compound is the same The second organic compound is an organic compound that exhibits electron-acceptance, and the fifth organic compound is a luminescent center The first substance is an alkali metal or alkaline earth metal in elemental form, or an organic complex. The first is a compound, and the HOMO level of the second organic compound is -5.7 eV or higher. -5.4 eV or less, and the HOMO level of the third organic compound and the second organic compound. the difference between the levels is 0.2 eV or less, and the HOMO level of the third organic compound is the second organic compound is the same as or deeper than the HOMO level of the compound, and the seventh organic compound has an electric field intensity [V / c m] has an electron mobility of 1×10 -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less, the HOMO level of the seventh organic compound is -6.0 eV or higher, and the fourth layer has a region with a high content of the seventh organic compound in the thickness direction thereof and a portion with a low content of the seventh organic compound, wherein the content of the seventh organic compound the portion with a low content of the seventh organic compound is located closer to the light-emitting layer side than the portion with a high content of the seventh organic compound , and the light-emitting device has a degradation represented by a change in luminance of light emission obtained when a constant current is passed through the light-emitting device the light-emitting device has a curve having a maximum value.

[0017] Alternatively, according to another aspect of the present invention, there are provided an anode, a cathode, and a layer located between the anode and the cathode a light-emitting device comprising an EL layer, wherein the EL layer comprises a first layer and a second layer in order from the anode side a second layer, a third layer, a light-emitting layer, and a fourth layer, wherein the first layer is in contact with the anode the fourth layer is in contact with the light-emitting layer, and the first layer comprises a first organic compound and a comprises two organic compounds, the second layer comprises a third organic compound, and the third layer comprises a comprises four organic compounds, the light-emitting layer comprises a fifth organic compound and a sixth organic compound, and the fourth layer comprises a seventh organic compound and a first substance, and the first organic compound is the the organic compound exhibits electron accepting property with respect to the two organic compounds, and the second organic compound is a first having a hole-transporting skeleton, the third organic compound having a second hole-transporting skeleton, and the The fourth organic compound has a third hole-transporting skeleton, and the fifth organic compound is a luminescent central material. The first substance is an alkali metal or alkaline earth metal in elemental form, an organic complex, or It is one of the compounds, and the HOMO level of the second organic compound is -5.7 eV or greater and -5 0.4 eV or less, and the first hole transport skeleton, the second hole transport skeleton and the The third hole-transporting skeleton consists of, independently, a carbazole skeleton, a dibenzofuran skeleton, and a diben The seventh organic compound is either a zothiophene skeleton or an anthracene skeleton. The electron mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶. -7 cm 2 / V s or more 5×10 -5 cm 2 A substance with a saturation of / Vs or less, and the HOMO equivalent of the seventh organic compound. The temperature is -6.0 eV or higher, and the fourth layer is the seventh organic compound in the thickness direction. It has a portion in which the substance is abundant and a portion in which the seventh organic compound is abundant, and the The amount of organic compound 7 is greater on the side of the light-emitting layer than the portion where the amount of organic compound 7 is greater. There are areas where the amount is small, and the brightness of the light emitted when a constant current is passed through the light-emitting device This is a light-emitting device whose degradation curve, represented by a change, has a maximum value.

[0018] Alternatively, in another aspect of the present invention, in the above configuration, the portion in which the degradation curve exceeds 100% It is a light-emitting device that has a minute.

[0019] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, wherein the EL layer has a light-emitting layer and an electron transport layer, The electron transport layer comprises a first material and a second material, wherein the first material is an alkali metal or The second substance is either an element, organic complex, or compound of a rutile earth metal, and the second substance is electron An organic compound having transport properties, wherein the electron transport layer is the first material in the thickness direction The material has a portion in which the quantity of the substance is small and a portion in which the quantity of the first substance is large, and the first substance The portion with a higher abundance of the first substance is located on the light-emitting layer side than the portion with a lower abundance of the substance. It is a light-emitting device that is placed in a location.

[0020] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, wherein the EL layer has a light-emitting layer and an electron transport layer, The electron transport layer comprises a first material and a second material, wherein the first material is an alkali metal or The second substance is either an element, organic complex, or compound of a rutile earth metal, and the second substance is electron An organic compound having transport properties, wherein the electron transport layer is the second material in the thickness direction The substance has a portion with a high abundance of the substance and a portion with a low abundance of the second substance, and the second substance There is a region on the light-emitting layer side where the amount of the second substance is less than the region where the amount of the second substance is greater. It is a light-emitting device.

[0021] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. The first layer has a first organic compound and a second organic compound, and the second layer has a first organic compound. The third layer has three organic compounds, the third layer has a fourth organic compound, and the light-emitting layer has a fifth organic compound. The fourth layer has an organic compound and a sixth organic compound, and the fourth layer has a seventh organic compound and a first substance The first organic compound has properties and the second organic compound exhibits electron-accepting ability. The first substance is an alkali metal, the fifth organic compound is a luminescent central substance, and the first substance is an alkali metal or an alkaline earth metal element, organic complex, or compound, and the second is The HOMO level of the organic compound is between -5.7 eV and -5.4 eV, and the seventh organic compound The compound has an electron mobility of 1 × 10⁻¹⁰ at an electric field strength [V / cm] square root of 600. -7 cm 2 / Vs or more 5×10 -5 cm 2 The material is less than or equal to / Vs, and the fourth layer has a thickness direction In the region where the amount of the seventh organic compound is high, the amount of the seventh organic compound It has a portion with less of the seventh organic compound, and is located on the side of the light-emitting layer that is greater than the portion with a greater amount of the seventh organic compound. This is a light-emitting device in which there are regions where the amount of the seventh organic compound is low.

[0022] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. Furthermore, the fourth layer is in contact with the light-emitting layer, and the first layer is a first organic compound and The second layer has two organic compounds, and the third layer has a third organic compound, The luminescent layer has four organic compounds, and the luminescent layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance, and the first organic compound is the same The second organic compound is an organic compound that exhibits electron-acceptance, and the fifth organic compound is a luminescent center The first substance is an alkali metal or alkaline earth metal in elemental form, or an organic complex. The first is a compound, and the HOMO level of the second organic compound is -5.7 eV or higher. The electric field strength is -5.4 eV or less, and the seventh organic compound has a square root of 6 electric field strength [V / cm]. The electron mobility at 00 is 1 × 10⁻⁶ -7 cm 2 / Vs or more 5×10 -5 cm 2 / Vs or less The substance is such that the HOMO level of the seventh organic compound is -6.0 eV or higher, and Layer 4 has a portion in its thickness direction where the amount of the 7th organic compound is high, and the 7th It has a portion where the amount of the organic compound is small, and a portion where the amount of the seventh organic compound is large. A light-emitting device in which there is a portion on the light-emitting layer side where the amount of the seventh organic compound is small. That is the case.

[0023] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. Furthermore, the fourth layer is in contact with the light-emitting layer, and the first layer is a first organic compound and The second layer has two organic compounds, and the third layer has a third organic compound, The luminescent layer has four organic compounds, and the luminescent layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance, and the first organic compound is the same The second organic compound is an organic compound that exhibits electron-acceptance, and the fifth organic compound is a luminescent center The first substance is an alkali metal or alkaline earth metal in elemental form, or an organic complex. The first is a compound, and the HOMO level of the second organic compound is -5.7 eV or higher. -5.4 eV or less, and the HOMO level of the third organic compound and the second organic compound. The difference in levels is 0.2 eV or less, and the HOMO level of the third organic compound is the same as that of the second organic compound. The seventh organic compound is at the same or deeper level than the HOMO level of the organic compound, and the electric field strength [V / c The electron mobility at which the square root of m is 600 is 1 × 10 -7 cm 2 / Vs or more 5×10 -5 cm 2 The substance is less than or equal to / Vs, and the HOMO level of the seventh organic compound is -6.0eV or less. The fourth layer is above, and in the thickness direction, there is a portion where the amount of the seventh organic compound is abundant. It has a portion and a portion in which the amount of the seventh organic compound is small, and the presence of the seventh organic compound There is a region on the light-emitting layer side where the amount of the seventh organic compound is less than the region where the amount is greater. It is a light-emitting device.

[0024] Alternatively, another aspect of the present invention comprises an anode, a cathode, and a position located between the anode and the cathode. In a light-emitting device having an EL layer, the EL layer comprises, in order from the anode side, a first layer and a second layer It has two layers, a third layer, a light-emitting layer, and a fourth layer, and the first layer is in contact with the anode. Furthermore, the fourth layer is in contact with the light-emitting layer, and the first layer is a first organic compound and The second layer has two organic compounds, and the third layer has a third organic compound, The luminescent layer has four organic compounds, and the luminescent layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance, and the first organic compound is the same The second organic compound is an organic compound that exhibits electron-acceptance to the first organic compound. The third organic compound has a hole-transporting skeleton, and the third organic compound has a second hole-transporting skeleton, The fourth organic compound has a third hole-transporting skeleton, and the fifth organic compound is a luminescent central material. The first substance is an alkali metal or alkaline earth metal in elemental form, an organic complex, or It is one of the compounds, and the HOMO level of the second organic compound is -5.7 eV or greater and -5 0.4 eV or less, and the first hole transport skeleton, the second hole transport skeleton and the The third hole-transporting skeleton consists of, independently, a carbazole skeleton, a dibenzofuran skeleton, and a diben The seventh organic compound is either a zothiophene skeleton or an anthracene skeleton. The electron mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶. -7 cm 2 / V s or more 5×10 -5 cm 2 A substance with a saturation of / Vs or less, and the HOMO equivalent of the seventh organic compound. The temperature is -6.0 eV or higher, and the fourth layer is the seventh organic compound in the thickness direction. It has a portion in which the substance is abundant and a portion in which the seventh organic compound is abundant, and the The amount of organic compound 7 is greater on the side of the light-emitting layer than the portion where the amount of organic compound 7 is greater. This is a light-emitting device that has areas with low levels of light.

[0025] Alternatively, in another aspect of the present invention, in the above configuration, the seventh organic compound is anthracene bone It is a light-emitting device that is an organic compound with a specific property.

[0026] Alternatively, in another aspect of the present invention, in the above configuration, the seventh organic compound is anthracite. This is a light-emitting device that is an organic compound having a cene skeleton and a heterocyclic skeleton.

[0027] Alternatively, in another aspect of the present invention, in the above configuration, the electron mobility of the seventh organic compound However, it is a light-emitting device with an electron mobility lower than that of the sixth organic compound.

[0028] Alternatively, in another aspect of the present invention, in the above configuration, the HOMO of the fourth organic compound A light-emitting device in which the difference between the position and the HOMO level of the third organic compound is 0.2 eV or less. That is the case.

[0029] Alternatively, in another aspect of the present invention, in the above configuration, the HOMO of the fourth organic compound The light-emitting device has a position deeper than the HOMO level of the third organic compound.

[0030] Alternatively, in another aspect of the present invention, the second organic compound has a dibenzofuran skeleton. It is a light-emitting device made of organic compounds.

[0031] Alternatively, in another aspect of the present invention, the second organic compound and the third organic compound are the same. It is a light-emitting device made of material.

[0032] Alternatively, in another aspect of the present invention, the fifth organic compound in the above configuration is a blue fluorescent material. It is a light-emitting device.

[0033] Alternatively, in another aspect of the present invention, the above configuration includes a sensor, an operating button, a speaker, and It is an electronic device having a microphone.

[0034] Alternatively, in another aspect of the present invention, in the above configuration, a transistor or a substrate and It is a light-emitting device.

[0035] Alternatively, another aspect of the present invention is a lighting device having a housing and, in the above configuration.

[0036] In this specification, the term "light-emitting device" includes image display devices that use light-emitting devices. Also, connectors, such as anisotropic conductive film or TCP (Tape) may be attached to the light-emitting device. Module with Carrier Package attached, print to TCP destination. A module equipped with a wiring board, or a light-emitting device, with COG (Chip On Glas s) A module on which an IC (integrated circuit) is directly mounted by this method, if it has a light-emitting device. Furthermore, lighting fixtures and the like may have light-emitting devices. [Effects of the Invention]

[0037] In one aspect of the present invention, a novel light-emitting device can be provided, or a device with a good lifespan. We can provide light-emitting devices. Or, we can provide light-emitting devices with good luminous efficiency. It is possible.

[0038] Alternatively, in another aspect of the present invention, a highly reliable light-emitting device, electronic device, and display device are provided, respectively. It can be provided. Or, in another aspect of the present invention, a light-emitting device with low power consumption, Electronic devices and display devices can be provided, respectively.

[0039] Furthermore, the description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. Furthermore, other effects are... This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings Furthermore, it is possible to extract other effects from the descriptions in the claims and other documents. [Brief explanation of the drawing]

[0040] [Figure 1] Figures 1(A1), 1(A2), 1(B), and 1(C) are schematic diagrams of the light-emitting device. [Figure 2] Figures 2(A) and 2(B) illustrate the concept of extending lifespan. [Figure 3] Figures 3(A) and 3(B) illustrate the increase in brightness. [Figure 4] Figures 4(A) and 4(B) are conceptual diagrams of an active matrix type light-emitting device. [Figure 5] Figures 5(A) and 5(B) are conceptual diagrams of an active matrix type light-emitting device. [Figure 6] Figure 6 is a conceptual diagram of an active matrix type light-emitting device. [Figure 7] Figures 7(A) and 7(B) are conceptual diagrams of a passive matrix type light-emitting device. [Figure 8] Figures 8(A) and 8(B) are diagrams representing lighting devices. [Figure 9] Figures 9(A), 9(B1), 9(B2), and 9(C) are diagrams representing electronic devices. [Figure 10] Figures 10(A), 10(B), and 10(C) are diagrams representing electronic devices. [Figure 11] Figure 11 is a diagram representing a lighting device. [Figure 12] Figure 12 is a diagram representing a lighting device. [Figure 13] Figure 13 is a diagram showing an in-vehicle display device and lighting device. [Figure 14] Figures 14(A) and 14(B) are diagrams representing electronic devices. [Figure 15] Figures 15(A), 15(B), and 15(C) are diagrams representing electronic devices. [Figure 16] Figure 16 shows the luminance-current density characteristics of light-emitting devices 1 to 3 and comparative light-emitting device 1. [Figure 17]Figure 17 shows the current efficiency-luminance characteristics of light-emitting devices 1 to 3 and comparative light-emitting device 1. [Figure 18] Figure 18 shows the luminance-voltage characteristics of light-emitting devices 1 to 3 and comparison light-emitting device 1. [Figure 19] Figure 19 shows the current-voltage characteristics of light-emitting devices 1 to 3 and comparative light-emitting device 1. [Figure 20] Figure 20 shows the external quantum efficiency-luminance characteristics of light-emitting devices 1 to 3 and comparative light-emitting device 1. [Figure 21] Figure 21 shows the emission spectra of light-emitting devices 1 through 3 and comparative light-emitting device 1. [Figure 22] Figure 22 shows the normalized luminance-time variation characteristics of light-emitting devices 1 to 3 and comparative light-emitting device 1. [Figure 23] Figures 23(A1), 23(A2), 23(B1), and 23(B2) show the concentrations of the first substance in the electron transport layer. [Figure 24] Figures 24(A) and 24(B) show the results of the ToF-SIMS analysis. [Figure 25] Figure 25 shows the structure of the measuring element. [Figure 26] Figure 26 shows the current density-voltage characteristics of the measuring element. [Figure 27] Figure 27 shows the frequency characteristics of the calculated capacitance C in ZADN:Liq(1:1) at a DC voltage of 7.0V. [Figure 28] Figure 28 shows the frequency characteristics of ZADN:Liq(1:1) at a DC voltage of 7.0V with respect to -ΔB. [Figure 29] Figure 29 shows the electric field strength dependence characteristics of electron mobility in each organic compound. [Figure 30] Figure 30 shows the luminance-current density characteristics of light-emitting devices 4 and 5. [Figure 31]Figure 31 shows the current efficiency-luminance characteristics of light-emitting devices 4 and 5. [Figure 32] Figure 32 shows the luminance-voltage characteristics of light-emitting devices 4 and 5. [Figure 33] Figure 33 shows the current-voltage characteristics of light-emitting devices 4 and 5. [Figure 34] Figure 34 shows the external quantum efficiency-luminance characteristics of light-emitting devices 4 and 5. [Figure 35] Figure 35 shows the emission spectra of light-emitting devices 4 and 5. [Figure 36] Figure 36 shows the normalized luminance-time variation characteristics of light-emitting devices 4 and 5. [Figure 37] Figure 37 shows the luminance-current density characteristics of the light-emitting device 6. [Figure 38] Figure 38 shows the current efficiency-luminance characteristics of the light-emitting device 6. [Figure 39] Figure 39 shows the luminance-voltage characteristics of the light-emitting device 6. [Figure 40] Figure 40 shows the current-voltage characteristics of the light-emitting device 6. [Figure 41] Figure 41 shows the external quantum efficiency-luminance characteristics of the light-emitting device 6. [Figure 42] Figure 42 shows the emission spectrum of the light-emitting device 6. [Figure 43] Figure 43 shows the normalized luminance-time variation characteristics of the light-emitting device 6. [Figure 44] Figure 44 shows the luminance-current density characteristics of the light-emitting device 7. [Figure 45] Figure 45 shows the current efficiency-luminance characteristics of the light-emitting device 7. [Figure 46] Figure 46 shows the luminance-voltage characteristics of the light-emitting device 7. [Figure 47] Figure 47 shows the current-voltage characteristics of the light-emitting device 7. [Figure 48] Figure 48 shows the external quantum efficiency-luminance characteristics of the light-emitting device 7. [Figure 49] Figure 49 shows the emission spectrum of the light-emitting device 7. [Figure 50] Figure 50 shows the normalized luminance-time variation characteristics of the light-emitting device 7. [Figure 51] Figure 51 shows the luminance-current density characteristics of light-emitting devices 8 and 9. [Figure 52] Figure 52 shows the current efficiency-luminance characteristics of light-emitting devices 8 and 9. [Figure 53] Figure 53 shows the luminance-voltage characteristics of light-emitting devices 8 and 9. [Figure 54] Figure 54 shows the current-voltage characteristics of light-emitting devices 8 and 9. [Figure 55] Figure 55 shows the external quantum efficiency-luminance characteristics of light-emitting devices 8 and 9. [Figure 56] Figure 56 shows the emission spectra of light-emitting devices 8 and 9. [Figure 57] Figure 57 shows the normalized luminance-time variation characteristics of light-emitting devices 8 and 9. [Modes for carrying out the invention]

[0041] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is as follows Not limited to the description, the form and details thereof may be described without departing from the spirit and scope of the present invention. Those skilled in the art will readily understand that the invention can be modified in various ways. Therefore, the present invention is as follows: This should not be interpreted as being limited to the contents described in the embodiments.

[0042] (Embodiment 1) Figures 1(A1) and (A2) show a diagram representing a light-emitting device according to one embodiment of the present invention. The light-emitting device has an anode 101, a cathode 102, and an EL layer 103, and the EL The layer comprises a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, and an electron transport layer 114. The hole transport layer 112 consists of the first hole transport layer 112-1 and the second hole transport layer. The electron transport layer 114 has layers 112-2 and is the first electron transport layer 114 as shown in Figure 1(A2) It is preferable to have -1 and a second electron transport layer 114-2.

[0043] In addition to these, the EL layer 103 in Figure 1(A1)(A2) also has an electron injection layer 11 Although diagram 5 is shown, the configuration of the light-emitting device is not limited to this. If it has the necessary functionality, it may include layers with other functions.

[0044] The hole injection layer 111 contains a first organic compound and a second organic compound. The compound is a substance that exhibits electron-accepting properties towards the second organic compound. The object has a relatively deep HOMO level between -5.7eV and -5.4eV. It is a substance that possesses the following properties: The second organic compound has a relatively deep HOMO level. The induction of holes is moderately suppressed, and the injection of induced holes into the hole transport layer 112 is facilitated. This is the result.

[0045] The first organic compound has an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) Organic compounds such as the above can be used, and from among such substances, the second organic compound A suitable substance that exhibits electron-accepting properties should be selected for this purpose. 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) Examples include fluoro-7H-pyrene-2-ylidene)malononitrile, etc. Chemical compounds such as HAT-CN have electron-withdrawing groups bonded to condensed aromatic rings containing multiple complex atoms. The compound is preferably thermally stable. Also, electron-withdrawing groups (especially halogen groups such as fluoro groups) are preferable. Radialene derivatives having a cyano group or other cyano group are preferred because they have very high electron-accepting properties.[3] Specifically, α,α',α''-1,2,3-cyclopropanetriylidentris[ 4-Cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α ''-1,2,3-cyclopropanetriylidetris[2,6-dichloro-3,5-di Fluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''- 1,2,3-Cyclopropanetriylidentris[2,3,4,5,6-Pentafluoro Examples include benzeneacetonitrile.

[0046] The second organic compound is preferably an organic compound having hole transport properties, such as carbazeo. One of the following skeletons: dibenzofuran skeleton, dibenzothiophene skeleton, or anthracene skeleton It is more preferable to have a dibenzofuran ring or dibenzothiophene. Aromatic amines having ring-containing substituents and aromatic monoamines having a naphthalene ring are preferred. Aromatic molecules in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It may also be a noamine. Furthermore, these second organic compounds may be N,N-bis(4-biface If the material has a nylamino group, it is possible to create a light-emitting device with a good lifetime. Therefore, it is preferable. Specifically, the second organic compound described above is N-(4-biph Phenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine ( Abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]na Phtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6- Phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltri Phenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[ b)Naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N- Bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3- d]Furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-( Dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBf) BB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl -4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4' '-Diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl )phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi) ,4-(2;1'-binaphthyl-6-yl)-4',4''-diphenyltriphenyl Min (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaf (Tyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-di Phenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: B BAPβNB-03), 4-(6;2'-binaphthyl-2-yl)-4',4''-diph Phenyltriphenylamine (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''-diphenyltri Phenylamine (abbreviation: BBAβNαNB), 4-(1;2'-binaphthyl-5-yl) -4',4''-diphenyltriphenylamine (abbreviation: BBAβNαNB-02), 4 -(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (Abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl [Phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi) , 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyl Nyltriphenylamine (abbreviation: TPBiAβNBi), 4-(1-naphthyl)-4'- Phenyltriphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl ) Triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4 '-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: Y GTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl [Nyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-0) 2) 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2- Naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[ 4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-na Phthyl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: P CBNBSF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-s Pyrobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1, 1'-biphenyl]-4-yl)-9,9'-spirobio[9H-fluorene]-4-amine N (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9, 9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio[9H-fluoren ]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl (Tyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF) , N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran- 4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl Lu-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAF) LP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine n (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluorene- 9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4 '-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PC) BA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole- 3-Iyl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4 '-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PC) BANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol) (Il-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4 -(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-bif Luolen-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl) )-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole-3-yl) Examples include [enyl]-9H-fluorene-2-amine (abbreviation: PCBBiF), etc. ru.

[0047] The composition of the first organic compound and the second organic compound in the hole injection layer 111 is 1:0.0 A ratio of 1 to 1:0.15 (by weight) is preferred. More preferably, 1:0.0 The ratio is 1 to 1:0.1 (by weight).

[0048] The hole transport layer 112 comprises a first hole transport layer 112-1 and a second hole transport layer 112-2. It is preferable that the first hole transport layer 112-1 is more positive than the second hole transport layer 112-2. It is assumed to be located on the pole 101 side. The second hole transport layer 112-2 is an electron blocking layer. It may also perform the functions of both simultaneously.

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

[0050] The third and fourth organic compounds are hole-transporting organic compounds. Preferably, the third organic compound and the fourth organic compound are used as the second organic compound. Organic compounds that can perform this function can be used in the same way.

[0051] In the HOMO levels of the second organic compound and the third organic compound, the third organic compound The HOMO level of the composite material is deeper, and the materials are selected such that the difference is 0.2 eV or less. It is preferable to do so.

[0052] Furthermore, the HOMO level of the third organic compound and the HOMO level of the fourth organic compound are different. It is preferable that the HOMO level of the organic compound is deeper. Furthermore, the difference should be less than 0.2 eV. It is best to select the materials in the following order: H of the second to fourth organic compounds. Because the OMO levels have the above-described relationship, holes are smoothly injected into each layer. This prevents increases in the driving voltage and insufficient holes in the light-emitting layer.

[0053] Furthermore, it is preferable that the second to fourth organic compounds each have a hole-transporting skeleton. It seems that the HOMO levels of these organic compounds become too shallow for the hole-transporting skeleton in question. Carbazole skeleton, dibenzofuran skeleton, dibenzothiophene skeleton and anthrace A navy skeleton is preferred. Furthermore, these hole-transporting skeletons are preferable to materials in adjacent layers (for example, a second navy skeleton). Common to the organic compound and the third organic compound or the third organic compound and the fourth organic compound Having these is preferable because it facilitates hole injection. In particular, as hole transport frameworks A dibenzofuran skeleton is preferred.

[0054] Also, materials contained in adjacent layers (for example, a second organic compound and a third organic compound or the If the third organic compound and the fourth organic compound are made of the same material, hole injection becomes smoother. Therefore, it is preferable. In particular, a configuration in which the second organic compound and the third organic compound are made of the same material is preferred. It's nice.

[0055] The light-emitting layer 113 has a fifth organic compound and a sixth organic compound. The fifth organic compound The sixth organic compound is a luminescent central material and a host material for dispersing the fifth organic compound. It is a material. Furthermore, the light-emitting layer 113 is different from both the fifth organic compound and the sixth organic compound. It is acceptable to include other ingredients at the same time.

[0056] Whether the luminescence center material is a fluorescent material or a phosphorescent material, it exhibits thermally activated delayed fluorescence. It can be a material exhibiting (TADF) or any other luminescent material. Also, a single layer Even if it is, it may consist of multiple layers. In one aspect of the present invention, the light-emitting layer 113 is This method is more preferably applied to layers that exhibit fluorescence, particularly layers that exhibit blue fluorescence. It is possible.

[0057] In the light-emitting layer 113, possible materials that can be used as fluorescent light-emitting materials include, for example, Examples include those listed below. Other fluorescent materials can also be used.

[0058] 5,6-Bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyri Zin (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-antri [Lu)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N, N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl] )phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bi Su(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene- 9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn) ), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-di Phenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazo (Abbreviated) 4'-(10-phenyl-9-anthryl)triphenylamine ( Name: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-dife Nyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl Nyl-N-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole -3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert- Butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-antryl)-4'- (9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA) PA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4, 1-Phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (Abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2 -Anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA) , N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'- Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N', N',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]Crystal N-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-i [Lu)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation) :2PCABPhA),N-(9,10-diphenyl-2-anthryl)-N,N',N '-Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,1 0-Bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-to Riphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis (1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl) [phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N ,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 54 5T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 5,12-bi Su(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BP) T), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl- 4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-meth Ru-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolidi [-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-Tetrakis(4-methylphenyl)tetracene-5, 11-Diamine (abbreviation: p-mPhTD), 7,14-Diphenyl-N,N,N',N' -Tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluorantene-3,1 0-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1, 1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij ]Quinolysin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitol Lu (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7- Tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolidine [-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: D CJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl} -4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2 ,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6 Trahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-p Ran-4-ylidene propanedinitrile (abbreviation: BisDCJ™), N,N'-(P Len-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-carbazole-2-yl)-N-phenylamino]naphtho[2, 3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-0 2) 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naph [2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(I Examples include V)-02). In particular, 1,6FLPAPrn and 1,6mMemFLPA Prn, 1,6BnfAPrn-03 and other pyrendiamine compounds are examples of condensed aromas. Fragrance diamine compounds are preferred because they have high hole-trapping properties and excellent luminescence efficiency and reliability. It seems so.

[0059] In the light-emitting layer 113, when a phosphorescent material is used as the light-emitting central material, Possible materials include, for example, the following:

[0060] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H -1,2,4-triazole-3-yl-κN 2 ]phenyl-κC}iridium(III ) (abbreviation: [Ir(mpptz-dmp)3]), Tris(5-methyl-3,4-diphen) Iridium(III) (abbreviation: [Ir(Mpt) z)3]), Tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H -1,2,4-Triazolat] Iridium(III) (Abbreviation: [Ir(iPrptz-3 Organometallic iridium complexes having a 4H-triazole skeleton, such as b)3]), and Tris [3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-tria Zolato] Iridium (III) (abbreviation: [Ir(Mptz1-mp)3]), Tris (1 -Methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium (III) (Abbreviation: [Ir(Prptz1-Me)3]) 1H-triazole bone Organometallic iridium complexes having a skeleton, and fac-tris[1-(2,6-diisopropyl phenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: Ir (iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimi dazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: Ir(dmp impt-Me)3]), which are organometallic iridium complexes having an imidazole skeleton; bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ iridium( III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4' ,6'-difluorophenyl)pyridinato-N,C 2’ iridium(III) picolina te (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)f enyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: Ir( CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyri dinato-N,C 2’ iridium(III) acetylacetonate (abbreviation: FIr(ac ac)]), which are organometallic iridium complexes having, as a ligand, a phenylpyridine derivative having an electron-withdrawing group; and the above-mentioned iridium complexes can be mentioned. These are compounds that emit blue phosphorescence, and are compounds having an emission peak from 440 nm to 520 nm.

[0061] Further, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)irr idium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis (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-phenylp rimidinato]iridium(III) (abbreviation: [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)]) organometallic iridium complexes having a pyrimidine skeleton such as organometallic iridium complexes, (acetylacetonato)bis(3,5-dimethyl-2-phenyl pyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac) ), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyra zinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]) organometallic iridium complexes having a pyrazine skeleton such as, tris(2-phenylpyridi nato-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(be Iridium (III) (abbreviation: [Ir(bzq)3]), Tris (2-phenylquinolinato-N,C 2’ Iridium(III) (abbreviation: [Ir(pq) 3]), bis(2-phenylquinolinato-N,C 2’ Iridium(III) acetylated Setanate (abbreviation: [Ir(pq)2(acac)]) is a pyridine skeleton-containing substance In addition to iridium metal complexes, tris(acetylacetonate)(monophenanthroline) Rare earth metals such as rubium(III) (abbreviation: [Tb(acac)3(Phen)]) Examples include complexes. These are compounds that mainly exhibit green phosphorescence, starting from 500 nm. It has an emission peak at 600 nm. Note that it is an organometallic iridium with a pyrimidine skeleton. The complex is particularly preferred because it exhibits outstanding reliability and luminescence efficiency.

[0062] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimid Sodium iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis(Ir(5mdppm)2(dibm)]), [4,6-Bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridi Um(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di( Naphthalene-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) Organometallic gold with a pyrimidine skeleton, such as (abbreviation: [Ir(d1npm)2(dpm)]) Iridium complexes of the genus, and (acetylacetonato)bis(2,3,5-triphenylpyrazine Iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2, 3,5-Triphenylpyrazinate)(dipivaloylmethanato) Iridium(III) (abbreviated) Name: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis (4-Fluorophenyl)quinoxalinato] Iridium(III) (Abbreviation: [Ir(Fd Organometallic iridium complexes having a pyrazine skeleton such as pq)2(acac)]) and RIS(1-phenylisoquinolinato-N,C) 2’ ) Iridium(III) (Abbreviation: [Ir (piq)3]), bis(1-phenylisoquinolinato-N,C 2’ Iridium (II) I) Pyridogenated acetylacetonate (abbreviation: [Ir(piq)2(acac)]) In addition to organometallic iridium complexes with a n skeleton, 2, 3, 7, 8, 12, 13, 17, 18 -Octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) Platinum complex and Tris(1,3-diphenyl-1,3-propanedionato)(monophenate Nanthroline europium(III) (abbreviation: [Eu(DBM)3(Phen)]), Tris[1-(2-tenoyl)-3,3,3-trifluoroacetonate](monophenane) Like trolin europium(III) (abbreviation: [Eu(TTA)3(Phen)]) Examples include rare earth metal complexes. These are compounds that exhibit red phosphorescence, and 60 It has an emission peak from 0 nm to 700 nm. Furthermore, it is an organometallic compound with a pyrazine skeleton. The lydium complex yields a red emission with good chromaticity.

[0063] In addition to the phosphorescent compounds described above, known phosphorescent materials may also be selected and used. stomach.

[0064] TADF materials include fullerenes and their derivatives, acridines and their derivatives, and eosin. Derivatives or the like can be used. In addition, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (P d) and other metal-containing porphyrins are mentioned. Examples of the metal-containing porphyrin include for example, protoporphyrin-tin fluoride complex represented by the following structural formula (SnF2(Pro to IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphy rin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4M e)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphy rin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin -platinum chloride complex (PtCl2OEP) and the like are also mentioned.

[0065]

Chemical Formula

[0066] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phen ylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine ( abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2- yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzT zn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-ca rbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbre viation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl ]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4 -(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5- Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-di Methyl-9H-acridin-10-yl)-9H-xanthene-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 π electrons such as clidine-9,9'-anthracene]-10'-one (abbreviated as ACRSA). Heterocyclic compounds having either or both an excess heteroaromatic ring and a π-electron-deficient heteroaromatic ring are also used. It is possible. The heterocyclic compound is a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring. Because it has a ring, it has high electron transport and hole transport properties, which is desirable. In particular, π electron transport Among skeletons having foot-shaped heteroaromatic rings, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyr The radin skeleton, pyridazine skeleton, and triazine skeleton are preferred because they are stable and reliable. It seems so. In particular, the benzophropyrimidine skeleton, the benzothienopyrimidine skeleton, and benzophropyrimidine skeleton. The radin skeleton and benzothienopyrazine skeleton are preferred due to their high acceptability and good reliability. Furthermore, among skeletons having a π-electron-rich heteroaromatic ring, the acridine skeleton and phenoxy The sazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are, Because it is stable and reliable, it is preferable to have at least one of the said skeletons. The oran skeleton is the dibenzofuran skeleton, and the thiophene skeleton is the dibenzothiophene skeleton. Each of these is preferable. Furthermore, as for the pyrrole skeleton, the indole skeleton and carbazole are preferred. Skeleton, indolocarbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H- The rubazole-3-yl)-9H-carbazole skeleton is particularly preferred. A substance in which a heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is a π-electron-rich heteroaromatic ring. The electron-donating and electron-accepting properties of the π-electron-deficient heteroaromatic ring both become stronger, and the S1 and T1 levels Because the energy difference between positions becomes smaller, thermally activated delayed fluorescence can be obtained efficiently, especially This is preferable. Furthermore, instead of a π-electron-deficient heteroaromatic ring, an electron-withdrawing group such as a cyano group may be attached. Combined aromatic rings may also be used. In addition, as π-electron-rich skeletons, aromatic amine skeletons and ferrous metals may be used. Nadine skeletons and the like can be used. Also, as π-electron-deficient skeletons, xanthene skeletons, Thioxanthene dioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazo Boron skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane and volanthrene, and benzyl Aromatic rings or heteroaromatic rings having a nitrile group or cyano group, such as zonitrile or cyanobenzene. Carbonyl skeletons such as fragrant rings, benzophenone, phosphine oxide skeletons, sulfone skeletons, etc. It can be used. Thus, π-electron-deficient heteroaromatic rings and π-electron-excess heteroaromatic rings Using a π-electron-deficient skeleton and a π-electron-excess skeleton instead of at least one of the rings is possible. can.

[0067] [ka]

[0068] Furthermore, TADF material is a substance represented by the following general formulas (G1) to (G11). It is preferable.

[0069] [ka]

[0070] [ka]

[0071] However, in the above general formula (G1), R 1 ~R 5 At least one of them represents a cyano group, R 1 ~R 5 At least one of them is a substituted or unsubstituted 9-carbazolyl group, or substituted or Unsubstituted 1,2,3,4-tetrahydro-9-carbazolyl group, substituted or unsubstituted 1 - Represents an indolyl group, or a substituted or unsubstituted diarylamino group, and the remaining R 1 ~ R 5 Each of these independently represents a hydrogen atom or a substituent.

[0072] Furthermore, in the above general formula (G2), R 11 and R 12 Each of them independently is a hydrogen atom or any substituent, where A is a heteroaryl group or which may have substituents. At least one arylamino group, which may have a substitution group, directly or otherwise with respect to an aromatic group This represents a substituent bonded to the 4-carbon of the pyridine ring via [a specific symbol].

[0073] Furthermore, in the above general formula (G3), Ar 1 ~Ar 3 represents an aryl group, and at least 1 One is substituted with a dibenzo-1,4-oxazine group or a dibenzo-1,4-thiazine group. It represents an aryl group.

[0074] Furthermore, in the above general formula (G4), X is a substituted or unsubstituted aromatic hydrocarbon group, substituted Alternatively, an unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or an aromatic Substituted by a group selected from a group hydrocarbon group, an aromatic heterocyclic group, or a fused polycyclic aromatic group. This represents a disubstituted amino group, where Y is a hydrogen atom, deuterium atom, fluorine atom, chlorine atom, or cyanonucleotide. A linear or branched chain having 1 to 6 carbon atoms, which may have a nitro group, substituents alkyl groups, cycloalkyl groups having 5 to 10 carbon atoms which may have substituents, Linear or branched alkenyl groups having 2 to 6 carbon atoms, which may have substituents. , linear or branched alkylo having 1 to 6 carbon atoms, which may have substituents A xy group, a cycloalkyloxy group having 5 to 10 carbon atoms which may have substituents, Substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, and substituted groups Alternatively, an unsubstituted condensed polycyclic aromatic group, a substituted or unsubstituted aryloxy group, or an aromatic Substituted by a group selected from a group hydrocarbon group, an aromatic heterocyclic group, or a fused polycyclic aromatic group. R represents a disubstituted amino group. 21 , R 22 , R 25 ~R 28 They are the same but different Also, each is independently a hydrogen atom, deuterium atom, fluorine atom, chlorine atom, cyano group, and nitrate. A linear or branched alkyl group having 1 to 6 carbon atoms, which may have substituents. A cycloalkyl group, which may have substituents, cycloalkyl groups of 5 to 10 carbon atoms, substituents A linear or branched alkenyl group having 2 to 6 carbon atoms, which may be present, a substituent A linear or branched alkyloxy group having 1 to 6 carbon atoms, which may have a linear or branched alkyloxy group A cycloalkyloxy group having 5 to 10 carbon atoms, which may have substituents, or may be substituted. k is an unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted group. Substituted condensed polycyclic aromatic groups, substituted or unsubstituted aryloxy groups, or aromatic hydroxyl groups Diposition substituted with a group selected from an elementary group, an aromatic heterocyclic group, or a fused polycyclic aromatic group A substituted amino group, consisting of a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. They may be connected to each other via their offspring to form a ring.

[0075] Furthermore, in the above general formula (G5), A 1 ~A 3 Each is independently substituted or unsubstituted diben This represents the zofuranil group.

[0076] Furthermore, in the above general formula (G6), R 31 ~R 34 And a~h are each independent of Therefore, hydrogen atoms, substituted or unsubstituted C1-C20 alkyl groups, substituted or unsubstituted Alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, represents an amino group.

[0077] Furthermore, in the above general formula (G7), R 41 ~R 48 Each is an independent hydrogen atom or electron A donor group, where at least one represents an electron-donating group. 49 ~R 56 Each of them independently An electron-withdrawing group other than an elementary atom or a triazino group, wherein at least one is a triazino group or Represents an external electron-withdrawing group. However, R 41 ~R 56 11 to 14 of them are hydrogen atoms. .

[0078] Furthermore, in the above general formula (G8), R 61 ~R 68 and R 77 Each of them independently produces hydrogen A child or electron donor, where at least one represents an electron donor. 69 ~R 76 teeth, Each is an electron-withdrawing group that does not have a lone pair of electrons on a hydrogen atom or at the α-position. Z is a single bond The combination or =C=Y represents S, C(CN)2, or C(COOH)2. And when Z is a single bond, R 69 ~R 76 At least one of them has a lone pair of electrons at the α position It is an electron-withdrawing group.

[0079] Furthermore, in the above general formula (G9), ring α condenses with an adjacent ring at any position in formula (g9-1 The aromatic ring is represented by (g9-2), where ring β is condensed with an adjacent ring at any position. It represents a heterocycle. In formulas (G9) and (g9-2), Ar is independently an aromatic hydrocarbon group or This represents an aromatic heterocyclic group. In formulas (G9) and (g9-1), R is independently either hydrogen or a single carbon atom. ~10 alkyl groups, alkoxy groups with 1 to 10 carbon atoms, alkylthio groups with 1 to 10 carbon atoms , alkylamino groups with 1 to 10 carbon atoms, acyl groups with 2 to 10 carbon atoms, a group with 7 to 20 carbon atoms Larquil groups, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, and substituted or This is a monovalent substitution selected from the group consisting of unsubstituted aromatic 6-membered heterocyclic groups with 3 to 30 carbon atoms. It is a group, and adjacent substituents may bond to each other to form a ring. n is a constant between 1 and 4. To indicate a number.

[0080] Furthermore, in the above general formula (G10), X 1 , X 2 , X 3 They may be the same or different, Each independently consists of a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, and substitution. Linear or branched alkyl groups having 1 to 6 carbon atoms, which may have a group, substitution A cycloalkyl group having 5 to 10 carbon atoms, which may have a group, and which have a substituent. A linear or branched alkenyl group having 2 to 6 carbon atoms, which may also have substituents. A linear or branched alkyloxy group having 1 to 6 carbon atoms, which may have substituents. A cycloalkyloxy group having 5 to 10 carbon atoms may be present, substituted or unsubstituted. Aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed groups Polycyclic aromatic groups, substituted or unsubstituted aryloxy groups, or aromatic hydrocarbon groups, fragrance Disubstituted amino groups substituted with groups selected from heterocyclic or fused polycyclic aromatic groups And at least X 1 , X 2 , X 3 One of these is a substituted or unsubstituted aroma. Group hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed polycyclic aromatic groups Selected from aromatic groups, aromatic hydrocarbon groups, aromatic heterocyclic groups, or fused polycyclic aromatic groups. It is assumed to be a disubstituted amino group substituted with the Ar group. 4 is either substituted or not substituted A divalent aromatic hydrocarbon group, a substituted or unsubstituted divalent heteroaromatic hydrocarbon group, or R represents a substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon group. 81 ~R 86 , R 89 ~R 94 These may be identical or different from one another, and each can be independently a hydrogen atom, a deuterium atom, and a fluorine atom. Elementary atoms, chlorine atoms, cyano groups, nitro groups, and carbon atoms having 1 or more which may have substituents a linear or branched alkyl group having 1 to 6 carbon atoms, an optionally substituted 5 to 10 cycloalkyl group, an optionally substituted linear or branched alkenyl group having 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted 5 to 10 cycloalkyloxy group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group, a substituted or unsubstituted ary loxy group, or a disubstituted amino group substituted with a group selected from the group consisting of an aromatic hydrocarbon group, an aromatic heterocyclic group and a fused polycyclic aromatic group, wherein the groups may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.

[0081] Further, in the above general formula (G11), R 101 to R 104 each independently represent a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group, and R 105 and R 106 each independently represent a substituted or unsubstituted alkyl group, and R 107 , R 108 and R 10 9 each independently represent a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group, n1 to n4 and n7 each independently represent any integer of 0 to 4, n5 and and n6 each independently represent any integer of 0 to 3, and n8 and n9 each independently represent any integer of 0 to 5 . R 101 to R 109where n1 to n9 respectively corresponding to each are 2 or more integers, a plurality of R 101 may be the same as or different from each other, R 102 to R 109 also follow the same rule.

[0082] Note that a TADF material has a small difference between the S1 level and the T1 level, and can convert energy from triplet excitation energy to singlet excitation energy via reverse intersystem crossing Therefore, triplet excitation energy can be up-converted into singlet excitation energy (reverse intersystem crossing) using a small amount of thermal energy, and singlet excited states can be generated efficiently. In addition, triplet excitation energy can be converted into luminescence. .

[0083] Further, an exciplex that forms an excited state with two types of substances (also called exciplex) has an extremely small difference between the S1 level and the T1 level, and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy.

[0084] As an index for the T1 level, a phosphorescence spectrum observed at a low temperature (e.g., from 77K to 10K) may be used. For a TADF material, when a tangent is drawn at the short-wavelength edge of the fluorescence spectrum, the energy corresponding to the wavelength of the extrapolated line is taken as the S1 level; when a tangent is drawn at the short- wavelength edge of the phosphorescence spectrum, and the energy corresponding to the wavelength of the extrapolated line is taken as the T1 level,[ the difference between S1 and T1 is preferably 0.3 eV or less, more preferably 0.2 eV or less.

[0085] ​​Furthermore, when using TADF material as the luminescence center material, the S1 level of the host material is TADF. It is preferable that the S1 level of the material is higher than the T level of the host material. Also, the T1 level of the host material is higher than the T level of the TADF material. It is preferable that the level is higher than level 1.

[0086] The host material for the light-emitting layer may be an electron-transporting material or a hole-transporting material, or the above Various carrier transport materials, such as TADF materials, can be used.

[0087] Materials with hole transport properties include those having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton. A compound is preferred. For example, 4,4'-bis[N-(1-naphthyl)-N-phenyl Mino]biphenyl (abbreviation: NPB), 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-phenylamino ] Biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9) -yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenyl) Nylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl Lu-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated name) :PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazo (3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl )-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation) :PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-ka Luvazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl -N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl] Fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl Nyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2 Compounds having an aromatic amine skeleton such as -amine (abbreviation: PCBASF), and 1,3- Su(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl) Biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenyl Nilcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazo Compounds having a carbazole skeleton, such as (PCCP) (abbreviation: PCCP), and 4,4',4'' -(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P) -II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-i [Phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9- Phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene Compounds with a thiophene skeleton, such as (abbreviation: DBTFLP-IV), and 4,4',4' '-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P- II) 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl] }Dibenzofuran (abbreviation: mmDBFFLBi-II) and other furan skeletons Examples include compounds. Among those mentioned above, compounds having an aromatic amine skeleton and carbazoles are examples. Compounds with a skeletal structure offer good reliability, high hole transport properties, and reduced driving voltage. This is also preferable as it contributes to the effect. Furthermore, the organic compounds listed above as examples of the second organic compounds can also be used. It is possible to be there.

[0088] Examples of materials with electron transport properties include bis(10-hydroxybenzo[h]quinoli Sodium beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolate) )(4-phenylphenolate)aluminum(III) (abbreviation: BAlq), bis(8- Zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl) [Phenolate]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl) Metal complexes such as phenolate zinc(II) (abbreviated as ZnBTZ) and π-electron-deficient heteroatoms Organic compounds having a fragrant ring skeleton are preferred. Organic compounds having a π-electron-deficient hetero-aromatic ring skeleton. For example, 2-(4-biphenylyl)-5-(4-tert-butylphenyl )-1,3,4-Oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4- Phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxa [Diazole-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1] ,3,4-Oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO 11) 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl- 1H-Benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophene-4) -yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm Heterocyclic compounds having a polyazole skeleton such as -II), and 2-[3-(dibenzothioff) [phenyl-4-yl]phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDB) q-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]di Benzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-( 9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxali n (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)f [enyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-diben Dia, such as zothienyl(phenyl)pyrimidine (abbreviation: 4,6mDBTP2Pm-II) Heterocyclic compounds having a din skeleton, or 3,5-bis[3-(9H-carbazole-9-yl] )phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridine) Heterocyclization of pyridine skeletons such as [zyl]phenyl]benzene (abbreviation: TmPyPB) Compounds are one example. Among those mentioned above, heterocyclic compounds having a diazine skeleton and pyridine skeletons are examples. Heterocyclic compounds having are reliable and preferred. In particular, diazines (pyrimidines and Heterocyclic compounds with a pyrazine skeleton exhibit high electron transport properties and contribute to reducing the driving voltage. .

[0089] As for TADF materials that can be used as host materials, the previously mentioned TADF materials are... The same material can be used. When TADF material is used as the host material, TA The triplet excitation energy generated in the DF material is converted to a singlet excitation energy through reverse intersystem crossing. This is converted to a different material, and then energy is transferred to the light-emitting central material, thereby improving the luminescence efficiency of the light-emitting device. This can enhance the emission. At this time, the TADF material functions as an energy donor and emits light. The central substance functions as an energy acceptor.

[0090] This is very effective when the above-mentioned luminescence center material is a fluorescent material. In order to obtain high luminescence efficiency, the S1 level of the TADF material is the same as the S1 level of the fluorescent material. It is preferable that the T1 level of the TADF material is higher than the S1 level of the fluorescent material. A higher level is preferable. Therefore, the T1 level of the TADF material is the T1 level of the fluorescent material. A level higher than the current level is preferable.

[0091] Furthermore, T exhibits emission that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material. It is preferable to use ADF material. This allows the fluorescent material to be converted from TADF material. This is preferable because it allows for smoother transfer of excitation energy and efficient emission.

[0092] Furthermore, singlet excitation energy is efficiently generated from triplet excitation energy through reverse intersystem crossing. For this to occur, it is preferable that carrier recombination occurs in the TADF material. The triplet excitation energy generated by the DF material is transferred to the triplet excitation energy of the fluorescent material. It is preferable not to do so. To that end, the fluorescent material has a luminescent phosphodiolus ( It is preferable to have a protecting group around the skeleton that causes light emission. The protecting group is a π bond. Substituents that do not have a substituent are preferred, saturated hydrocarbons are preferred, specifically those having 3 to 10 carbon atoms. The alkyl group below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, carbon Examples include trialkylsilyl groups with a number between 3 and 10, and it is even preferable if there are multiple protecting groups. Substituents that do not have a π bond have poor carrier transport function, therefore carrier transport and The distance between the TADF material and the fluorescent material's luminescent phosphate is minimized without affecting carrier recombination. It can keep the distance away. Here, a luminescent group is the substance that causes light emission in a fluorescent substance. This refers to an atomic group (skeleton). The luminescent group preferably has a skeleton with π bonds and contains an aromatic ring. It is preferable that it has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of compound aromatic rings include the phenanthrene skeleton, stilbene skeleton, acridone skeleton, and pheno Examples include xazine skeletons and phenothiazine skeletons. In particular, naphthalene skeletons and anthracene skeletons. Skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetracene skeleton, pyrene skeleton It has a perylene skeleton, coumarin skeleton, quinacridone skeleton, and naphthobisbenzofuran skeleton. Fluorescent materials are preferred because they have a high fluorescence quantum yield.

[0093] When using a fluorescent material as the luminescent center material, the host material is an anthracene skeleton. Materials having an anthracene skeleton are preferred as host materials for fluorescent materials. When used in this way, it is possible to realize a light-emitting layer with good luminescence efficiency and durability. As for materials that have an anthracene skeleton, diphenylanthracene skeleton Because substances, especially those with a 9,10-diphenylanthracene skeleton, are chemically stable. It is preferable. Furthermore, if the host material has a carbazole skeleton, the hole injection and transport properties are high. This is preferable, but benzocarbazole bone is formed when a benzene ring is further condensed on carbazole. When a positive charge is present, the HOMO becomes about 0.1 eV shallower than that of carbazole, making it easier for holes to enter. This is preferable because it makes the host material less likely to cause problems. In particular, when the host material contains a dibenzocarbazole skeleton, The HOMO is about 0.1 eV shallower than that of Luvazole, making it easier for holes to enter, and It is suitable because it has excellent transportability and high heat resistance. Therefore, as a host material Preferably, the 9,10-diphenylanthracene skeleton and the carbazole skeleton ( These are substances that simultaneously possess a benzocarbazole skeleton or a dibenzocarbazole skeleton. Furthermore, from the viewpoint of hole injection and transport as described above, the carbazole skeleton has been replaced with benzofluorescein. A 9-fluorene skeleton or a dibenzofluorene skeleton may also be used. An example of such a substance is 9-fluorene. phenyl-3-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole PCzPA (abbreviation: PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9 H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthraceni [Phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl] -9-Anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgD BCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-ben Zo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10 -{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}an Tracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl) Examples include phenylanthracene (abbreviation: αN-βNPAnth), and in particular, CzP A, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good characteristics, This is a favorable choice.

[0094] Furthermore, the host material may be a mixture of multiple substances, and the mixed host material When used, a mixture of electron-transporting material and hole-transporting material is used. Preferably, by mixing an electron-transporting material with a hole-transporting material. Furthermore, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. This is possible. The weight ratio of the content of hole-transporting material to electron-transporting material is positive. The ratio of materials with pore transport properties to materials with electron transport properties should be 1:19 to 19:1.

[0095] Furthermore, phosphorescent materials can be used as part of the above-mentioned mixed materials. When using a fluorescent material as the central material for light emission, the excitation energy of the fluorescent material is transferred to the fluorescent material. It can be used as an energy donor that provides energy.

[0096] Furthermore, these mixed materials may form excited complexes. These excited complexes are luminescent materials. It forms an excited complex that emits light that overlaps with the wavelength of the lowest energy absorption band. By selecting the right combination, energy transfer becomes smoother, and luminescence is obtained more efficiently. This is preferable because it allows for a reduction in the drive voltage.

[0097] Furthermore, at least one of the materials forming the excitation complex may be a phosphorescent material. By doing so, the triplet excitation energy is efficiently converted to the singlet excitation energy through reverse intersystem crossing. It can be converted to -.

[0098] As a combination of materials that efficiently form excited complexes, HO is a material with hole transport properties. It is preferable that the MO level is above the HOMO level of the electron-transporting material. If the LUMO level of a material with electron-transporting properties is higher than or equal to the LUMO level of a material with electron-transporting properties Preferred. Note that the LUMO and HOMO levels of the material are controlled by cyclic voltammetry. From the electrochemical properties (reduction potential and oxidation potential) of the material measured by CV (coefficient of variation) It can be derived.

[0099] Furthermore, the formation of excited complexes is related to, for example, the emission spectrum of hole-transporting materials and electron-transporting properties. The emission spectrum of a material having the above properties, and the emission spectrum of a mixed film obtained by mixing these materials. In comparison, the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each individual material. Alternatively, this can be confirmed by observing a phenomenon (which has a new peak on the longer wavelength side). Alternatively, transient photoluminescence (PL) and electron transport of materials with hole transport properties. The transient PL of materials possessing certain properties and the transient PL of a mixed film obtained by mixing these materials are compared, and the mixing The transient PL lifetime of the film has a longer lifetime component than the transient PL lifetime of each material, or a delayed lifetime component. This can be confirmed by observing differences in transient responses, such as an increase in the proportion of the time. Furthermore, the transient PL mentioned above can be interpreted as transient electroluminescence (EL). No. That is, transient EL for hole-transporting materials, transient E for electron-transporting materials. By comparing the transient EL of L and mixed films and observing the differences in transient response, Excitation complex formation can be confirmed.

[0100] The electron transport layer 114 is provided in contact with the light-emitting layer 113 as shown in Figure 1(A1) and is the seventh organic It has a compound and the first substance. The seventh organic compound has electron transport properties that are more dominant than hole transport properties. It is an organic compound, and its electron mobility is such that the square root of the electric field strength [V / cm] is 600. te 1 × 10 -7 cm 2 / Vs or more 5×10 -5 cm 2 It must be an organic compound with a Vs of less than or equal to / Vs. Preferably, electrons are injected into the light-emitting layer by reducing the electron transportability in the electron transport layer. The amount can be controlled, preventing the light-emitting layer from becoming electron-excessive.

[0101] Furthermore, the seventh organic compound is preferably an organic compound having an anthracene skeleton. Furthermore, it is more preferable that the organic compound contains both an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing five-membered ring skeleton, and the nitrogen-containing five-membered ring skeleton is These are two complex rings, such as pyrazole rings, imidazole rings, oxazole rings, and thiazole rings. It is particularly preferable that the material has a nitrogen-containing five-membered ring skeleton in which atoms are included in the ring.

[0102] The first substance is an alkali metal or alkaline earth metal in elemental form, organic complex or compound. It is one of these, for example, Li, Li2O, etc. In particular, lithium organic A complex is preferred, and among them, 8-hydroxyquinolinatritium (abbreviation: Liq) is preferred. stomach.

[0103] Furthermore, the electron transport layer 114 is a mixture of the seventh organic compound and the first substance in the thickness direction. There are parts where the mixing ratio differs. This mixing ratio is due to the mixing ratio of the first substance on the cathode side being small. It is preferable that the mixing ratio is such that the time-of-flight type secondary ion mass spectrometry ( F-SIMS:Time-of-flight secondary ion mass This can be inferred from the amount of atoms or molecules detected by spectrometry. In parts of the mixture with different mixing ratios composed of different types of materials, ToF-SIMS analysis revealed The magnitude of each detected value corresponds to the relative abundance of the atom or molecule of interest. By comparing the detected amounts of the seventh organic compound and the first substance, the relative sizes of the mixtures can be estimated. It also becomes possible to attach it.

[0104] In other words, in the electron transport layer 114, the portion with a higher abundance of the seventh organic compound is located on the light-emitting layer side. This means that there is a region where the amount of the seventh organic compound is small, or in other words, In the subtransport layer 114, the amount of the first substance is less in the region closer to the light-emitting layer than in the region where the amount of the first substance is less. It can be said that there are parts where the quantity is high.

[0105] Furthermore, in the region where the amount of the seventh organic compound is high (the region where the amount of the first substance is low) The electron mobility is 1 × 10⁻⁶ at an electric field strength [V / cm] square root of 600. -7 cm 2 / Vs or more 5×10 -5 cm 2 It is preferable that it is less than or equal to / Vs.

[0106] Furthermore, as shown in Figure 1(A2), the electron transport layer 114 is configured to receive the first electron from the light-emitting layer 113 side. It is preferable to have a electron transport layer 114-1 and a second electron transport layer 114-2. The electron transport layer 114-1 and the second electron transport layer 114-2 are connected to the seventh organic compound and the first substance. These are layers with different mixing ratios, and the seventh organic compound and the first electron transport layer 114-1 The mixing ratio of substance 1 is the ratio of the seventh organic compound to the first substance in the second electron transport layer 114-2. The mixing ratio of the substances is different. Specifically, the mixing ratio of the first substance in the first electron transport layer 114-1 is different. The ratio is higher than the mixing ratio of the first material in the second electron transport layer 114-2, and the first electron The mixing ratio of the seventh organic compound in transport layer 114-1 is the same as in the second electron transport layer 114-2. It is preferable that the mixing ratio is lower than that of the seventh organic compound. These mixing ratios are as described above. As shown above, it is possible to infer this from the amount of atoms and molecules detected by ToF-SIMS analysis. Therefore, the amount of the first substance in the first electron transport layer 114-1 is equal to the amount of the second electron The amount of the first substance in electron transport layer 114-2 is greater than the amount of the first substance in electron transport layer 114 -1 The abundance of the seventh organic compound is the seventh organic compound in the second electron transport layer 114-2 It is preferable that the amount is smaller than the amount of the compound present.

[0107] Furthermore, the first electron transport layer 114-1 is closer to the light-emitting layer 113 than the second electron transport layer 114-2. It is sufficient that it is provided in the first electron transport layer 114-1 and the second electron transport layer 114-2 Other layers may exist in between.

[0108] Furthermore, the relative abundance of the seventh organic compound and the first substance is clearly divided into layers, as shown in Figure 1(A1). If there is no boundary, it may change continuously as shown in Figure 23(A1)(A2). If it can be seen that it is separated into layers as in Figure 1(A2), then see Figure 23(B1)(B 2) It may also change in a stepwise manner. In any case, in the electron transport layer 114, The first substance is located on the side of the light-emitting layer 113 that is lower than the region where the concentration of the first substance is low, which is the rate-limiting region for electron mobility. It is essential that a region with a high concentration of is provided. In this specification, for convenience, We have shown a method for estimating abundance, concentration, and mixing ratio using ToF-SIMS, but other detection methods are also available. Any method is acceptable as long as it can prove these points.

[0109] Here, Figures 24(A) and (B) show a light-emitting device according to one embodiment of the present invention, analyzed by ToF-SIMS. The results of the analysis are shown below. Figure 24(A) shows the results for m / z=6, i.e., lithium atoms. Based on the detection results, Figure 24(B) corresponds to the organic compound used as the seventh organic compound. This is the result of detecting molecular weight. Although there are differences in detection sensitivity, both methods are mixed with the device structure. It can be seen that the detection intensity reflects the combined ratio.

[0110] Furthermore, the seventh organic compound possesses electron transport properties and its HOMO level is -6.0 eV or higher. It is preferable that this be the case.

[0111] Other organic compounds that can be used as a seventh organic compound and possess electron transport properties include This refers to an organic compound having electron transport properties that can be used as the host material, or the above-mentioned firefly. The organic compounds listed as suitable for use as host materials for photoluminescent substances will be used. It is possible.

[0112] Furthermore, the electron mobility of the seventh organic compound at a square root of the electric field strength [V / cm] of 600 is Preferably, it is smaller than that of the sixth organic compound or the light-emitting layer 113.

[0113] When the light-emitting layer becomes electron-rich, a portion of the light-emitting region 113-1 appears as shown in Figure 2(A). Being limited to that area increases the burden on that part, accelerating its deterioration. The failure of electrons to recombine and their subsequent passage through the light-emitting layer also reduces the lifetime and luminous efficiency. In one aspect of the invention, by reducing the electron transportability in the electron transport layer 114, Figure 2( As in B), the light-emitting region 113-1 is expanded and the load on the material constituting the light-emitting layer 113 is distributed. By doing so, it is possible to provide light-emitting devices with a long lifespan and good luminous efficiency.

[0114] Furthermore, in a light-emitting device having such a configuration, a drive test under conditions of constant current density is performed. In the luminance degradation curve obtained by this method, there are cases where a shape with a maximum value is observed. Furthermore, the degradation curve of a light-emitting device according to one aspect of the present invention shows that the brightness increases over time. It may take on a shape that has parts. Light-emitting devices that exhibit such degradation behavior are what are called This can be offset by the increase in brightness, which is the rapid degradation that occurs during the initial stages of operation, known as initial degradation. This results in a light-emitting device with minimal initial degradation and a very good operating life. This becomes possible. Such light-emitting devices are called Recombination-Site T This will be referred to as an ailoring injection element (ReSTI element).

[0115] Furthermore, if we take the derivative of a degradation curve that has such a maximum value, there will be a region where the value is zero. Therefore, in one embodiment of the present invention, there is a portion in the derivative of the degradation curve that is zero. Optical devices exhibit low initial degradation and are light-emitting devices with a very good lifespan. Cut.

[0116] The behavior of the degradation curve described above is as shown in Figure 3(A), where electron transport in the electron transport layer Due to low mobility, recombination that does not contribute to luminescence occurs in the non-luminescent recombination region 120. This phenomenon is thought to be caused by the above. In the light-emitting device of the present invention having the above configuration, In the initial stages of motion, the hole injection barrier is small, and the electron transport properties of the electron transport layer 114 are relatively Due to the low level, the light-emitting region 113-1 (i.e., the recombination region) is shifted towards the electron transport layer 114. It is formed in this state. Also, the HOMO of the seventh organic compound contained in the electron transport layer 114 Since the energy level is relatively high at -6.0 eV or higher, some holes reach the electron transport layer 114. Therefore, recombination also occurs in the electron transport layer 114, and a non-luminescent recombination region 120 is formed. Oh, since the recombination region reaches inside the electron transport layer 114, the sixth organic compound and the seventh The difference in HOMO levels of the organic compounds is preferably within 0.2 eV.

[0117] Here, in the light-emitting device according to one aspect of the present invention, as the operating time elapses, the carrier The balance changes, and as shown in Figure 3(B), the light-emitting region 113-1 (recombination region) becomes the hole transport layer. It moves towards the 112 side. As the non-luminescent recombination region 120 decreases, the recombined carrier This makes it possible to effectively contribute the energy of A to light emission, resulting in increased brightness compared to the initial stage of operation. An increase occurs. This increase in brightness is a sudden decrease in brightness that appears in the initial stages of operation of the light-emitting device, so to speak. By offsetting initial degradation, we provide light-emitting devices with low initial degradation and a long operating life. This becomes possible.

[0118] In one embodiment of the present invention, a change in the carrier balance in the light-emitting device is due to the electron transport layer 114 This is thought to be caused by a change in electron mobility. A light-emitting device according to one aspect of the present invention , an organometallic complex of alkali metal or alkaline earth metal or chemical Although there is a concentration difference of the compound (first substance), between the region with a low concentration and the light-emitting layer, The configuration has regions with high concentrations. In other words, regions with low concentrations of the first substance have high concentrations. It has a configuration located on the cathode side of the region. The electron mobility of the electron transport layer 114 is alkali metal Alternatively, the higher the concentration of organometallic complexes or compounds of alkaline earth metals, the higher the electricity. The electron mobility of the electron transport layer 114 is limited by the region with a low concentration.

[0119] Here, the inventors have found that when a voltage is applied to drive the light-emitting device, alkali metal or An organometallic complex or compound of an alkaline earth metal (the first substance) is subjected to voltage on the anode side. We found that it diffuses towards the cathode side (from the region of high concentration to the region of low concentration). That is, Because the region with a higher concentration of the first substance is located closer to the anode than the region with a lower concentration, as the drive proceeds This improves the electron mobility of the electron transport layer. As a result, within the light-emitting device A change in carrier balance occurs, the recombination region shifts, and the shape of the degradation curve as described above changes. We were able to obtain a long-life light-emitting device.

[0120] A light-emitting device according to one aspect of the present invention having the above configuration is a light-emitting device with a very good lifespan. It can be used as a vice, especially in the region where degradation is extremely small, up to around LT95. It is possible to significantly extend lifespan.

[0121] Furthermore, the ability to suppress initial degradation is one of the major weaknesses of OLED devices. The issue of seizing, which is still a subject of discussion, and the pre-shipment aging process taken to reduce it. This makes it possible to significantly reduce the time between steps.

[0122] (Embodiment 2) Next, we will describe the detailed structure and materials of the light-emitting device mentioned above. One aspect of the present invention As described above, the light-emitting device consists of multiple layers between a pair of electrodes, an anode 101 and a cathode 102. It has an EL layer 103, and the EL layer 103 is at least from the anode 101 side, a hole injection layer 111, first hole transport layer 112-1, second hole transport layer 112-2, light-emitting layer 113 It includes an electron transport layer 114.

[0123] Other layers included in the EL layer 103 are not particularly limited, and include hole injection layers and hole transport layers. Layers such as electron transport layers, electron injection layers, carrier blocking layers, exciton blocking layers, and charge generation layers. Various layered structures can be applied.

[0124] Anode 101 is a metal, alloy, or conductive compound with a large work function (specifically, 4.0 eV or more). It is preferable to form them using materials and mixtures thereof. Specifically, for example, Indium tin oxide (ITO), silicon, etc. Or silicon dioxide-containing indium oxide-tin oxide, indium oxide-zinc oxide, oxide Examples include indium oxide (IWZO) containing tungsten and zinc oxide. These conductive metal oxide films are usually deposited by sputtering, but the sol-gel method is also used. Any method can be used to manufacture it. An example of a manufacturing method is indium oxide-zinc oxide. Sputtering is performed using a target to which 1-20 wt% zinc oxide has been added to indium oxide. There are methods such as the ring method for formation. Also, it contains tungsten oxide and zinc oxide. Indium oxide (IWZO) is found to be 0.5 to 5 times more tungsten oxide than indium oxide. Using a target containing wt% and 0.1-1 wt% zinc oxide, the sputtering method is used. It can also be formed from gold (Au), platinum (Pt), nickel (Ni), and tungsten. Gusten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co) copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride), etc. These include graphene, which can also be used. Note that here the work function is large and explicit While representative materials for forming the electrode have been listed, in one aspect of the present invention, the hole injection layer 1 11. An organic compound having hole transport properties and a substance exhibiting electron-accepting properties for said organic compound. Because a composite material containing these elements is used, the electrode material can be selected regardless of the work function.

[0125] The laminated structure of the EL layer 103 is as shown in Figure 1(A1)(A2) in this embodiment. Sea urchin, hole injection layer 111, first hole transport layer 112-1, second hole transport layer 112-2, Light-emitting layer 113, electron transport layer 114 (first electron transport layer 114-1, second electron transport layer 11 In addition to 4-2), a configuration having an electron injection layer 115, and as shown in Figure 1(B), Two types of configurations will be described, in which the inlet layer 115 is replaced with a charge generation layer 116. The materials that make up the layers are described below in detail.

[0126] Hole injection layer 111, hole transport layer 112 (hole transport layer 112-1, hole transport layer 112-2) , light-emitting layer 113 and electron transport layer 114 (electron transport layer 114-1, electron transport layer 114-2 Regarding this, since it was described in detail in Embodiment 1, the repetitive description will be omitted. Please refer to the description in State 1.

[0127] Between the electron transport layer 114 and the cathode 102, an electron injection layer 115 is provided, which is lithium fluoride. Alkaline compounds such as LiF, cesium fluoride (CsF), and calcium fluoride (CaF2) A layer containing an alkaline metal, an alkaline earth metal, or a compound thereof may be provided. Electron injection layer 1 15 is a layer made of an electron-transporting material containing alkali metals or alkaline earth metals or Products containing those compounds or electrides may also be used. Electrides and For example, a substance obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum. These are some examples.

[0128] In addition, instead of the electron injection layer 115, a charge generation layer 1 is placed between the electron transport layer 114 and the cathode 102. 16 may be provided (Figure 1(B)). The charge generation layer 116 is generated by applying a potential. A layer in which holes can be injected into the layer in contact with the cathode side and electrons into the layer in contact with the anode side. The charge generation layer 116 includes at least a P-type layer 117. This uses the composite material listed above as a material that can constitute the hole injection layer 111. It is preferable to form it. Furthermore, the P-type layer 117 is made of the materials described above as constituting the composite material. The structure may be constructed by laminating a film containing an acceptor material and a film containing a hole transport material. P-type layer 1 By applying an electric potential to 17, electrons are directed to the electron transport layer 114 and to the cathode 102. Holes are injected, and the light-emitting device starts working.

[0129] In addition to the P-type layer 117, the charge generation layer 116 also includes an electron relay layer 118 and an electron injection buffer. It is preferable that one or both of the layers 119 are provided.

[0130] The electron relay layer 118 contains at least an electron-transporting material, and the electron injection buffer layer 1 It has the function of preventing interaction between 19 and the P-type layer 117, thereby enabling smooth electron transfer. The LUMO level of the electron-transporting material contained in the relay layer 118 is in the P-type layer 117. The LUMO level of the electron-accepting material and the charge generation layer 116 in the electron transport layer 114 are in contact. It is preferable that the LUMO level is between the LUMO level of the material contained in the layer. Electron relay layer 118 The specific energy levels of the LUMO level in electron-transporting materials used are It is preferable to have a voltage of -5.0 eV or higher, preferably between -5.0 eV and -3.0 eV. As for the electron-transporting material used in the electron relay layer 118, phthalocyanine-based materials are used. It is preferable to use a metal complex having a metal-oxygen bond and an aromatic ligand.

[0131] The electron injection buffer layer 119 contains alkali metals, alkaline earth metals, rare earth metals, and These compounds (alkali metal compounds (oxides such as lithium oxide, halides, and carbonates) (including carbonates such as thium and cesium carbonate), alkaline earth metal compounds (oxides, halogens) Compounds of rare earth metals (including oxides, halides, and carbonates), or compounds of rare earth metals (including oxides, halides, and carbonates) It is possible to use materials with high electron injection capabilities, such as (m)).

[0132] Furthermore, the electron injection buffer layer 119 contains an electron transporting material and an electron donating material. If formed, the electron-donating substances are alkali metals, alkaline earth metals, and rare earth elements. Metals, and their compounds (alkali metal compounds (oxides such as lithium oxide, halogens) (including carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (oxidation) (including substances, halides, and carbonates), or compounds of rare earth metals (oxides, halides) In addition to carbonates, tetrathianaphthalene (abbreviation: TTN), nickelosene, and decane are also included. Organic compounds such as methyl nickerosene can also be used. Furthermore, substances with electron transport properties... In terms of quality, it is formed using the same material as the material that constitutes the electron transport layer 114 described earlier. It is possible.

[0133] As the material that forms cathode 102, gold with a small work function (specifically, 3.8 eV or less) is used. Compounds, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples of 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 Group 2 of the periodic table, and alloys containing them (MgAg, AlL i) Rare earth metals such as europium (Eu) and ytterbium (Yb), and those containing these Examples include alloys, etc. However, between the cathode 102 and the electron transport layer, an electron injection layer is provided. By providing this, regardless of the magnitude of the work function, Al, Ag, ITO, silicon, or acid Various conductive materials such as indium oxide-tin oxide containing silicon dioxide are used as cathode 102. It is possible to be there. These conductive materials are produced using dry methods such as vacuum deposition and sputtering, as well as inkjet methods. It is possible to deposit films using methods such as spin coating. Furthermore, wet deposition can be performed using the sol-gel method. It may be formed by a mold, or by a wet process using a paste of a metallic material.

[0134] Furthermore, various methods can be used to form the EL layer 103, regardless of whether they are dry or wet methods. This can be done using methods such as vacuum deposition, gravure printing, offset printing, and screen printing. You may use methods such as printing, inkjet printing, or spin coating.

[0135] Furthermore, each electrode or layer described above may be formed using different film deposition methods.

[0136] The configuration of the layer provided between the anode 101 and the cathode 102 is not limited to the above. No. However, the proximity of the light-emitting region to the metal used in the electrodes and carrier injection layer can lead to... To suppress the resulting quenching, holes are placed in a location away from the anode 101 and cathode 102. A configuration in which a light-emitting region is provided where electrons and other elements recombine is preferable.

[0137] Furthermore, the hole transport layer and electron transport layer in contact with the light-emitting layer 113, and especially the recombination in the light-emitting layer 113, The carrier transport layer near the region suppresses energy transfer from excitons generated in the light-emitting layer. Therefore, the band gap is the light-emitting material that makes up the light-emitting layer or the light contained in the light-emitting layer. It is preferable to use materials with a band gap larger than the band gap of the material itself. It seems so.

[0138] Next, we have a light-emitting device (multilayer element, tandem element) with a configuration in which multiple light-emitting units are stacked. The form of the (also called the child) will be explained with reference to Figure 1(C). This light-emitting device is positive This is a light-emitting device having multiple light-emitting units between the electrode and the cathode. The structure is substantially the same as the EL layer 103 shown in Figure 1(A1) or (A2). In other words, the light-emitting device shown in Figure 1(C) is a light-emitting device having multiple light-emitting units. The light-emitting devices shown in Figures 1(A1)(A2) and 1(B) have one light-emitting unit. It can be said to be a light-emitting device.

[0139] In Figure 1(C), a first light-emitting unit 511 and a cathode 502 are located between the anode 501 and the cathode 502. A second light-emitting unit 512 is stacked with the first light-emitting unit 511 and the second light-emitting unit A charge generation layer 513 is provided between the knit 512 and the cathode 502. These correspond to the anode 101 and cathode 102 in Figure 1(A1), respectively, and in the explanation of Figure 1(A1) The same thing described can be applied. Also, the first light-emitting unit 511 and the second The light-emitting unit 512 may have the same configuration or a different configuration.

[0140] When a voltage is applied to the anode 501 and cathode 502, the charge generation layer 513 generates a light from one of the light-emitting units. It has the function of injecting electrons into one unit and holes into the other light-emitting unit. That is, Figure In 1(C), when a voltage is applied such that the potential of the anode is higher than the potential of the cathode... In addition, the charge generation layer 513 injects electrons into the first light-emitting unit 511 and the second light-emitting unit Any method that injects a hole into T512 will suffice.

[0141] The charge generation layer 513 is formed with the same configuration as the charge generation layer 116 described in Figure 1(B). Preferably, composite materials of organic compounds and metal oxides have good carrier implantation and carrier transport properties. Due to its superior performance, it can achieve low-voltage and low-current operation. If the anode side of the net is in contact with the charge generation layer 513, the charge generation layer 513 will light up the unit. Since it can also serve as the hole injection layer of the net, the light-emitting unit does not require a hole injection layer. That's fine.

[0142] Furthermore, if an electron injection buffer layer 119 is provided in the charge generation layer 513, the electron injection buffer Since layer 119 plays the role of an electron injection layer in the anode-side light-emitting unit, the anode-side light emission The unit does not necessarily need to have an electron injection layer.

[0143] Figure 1(C) illustrates a light-emitting device having two light-emitting units, but there are also devices with three or more units. The same method can be applied to light-emitting devices that stack the above light-emitting units. As in the light-emitting device according to this embodiment, multiple light-emitting units are charged between a pair of electrodes. By separating and arranging the elements with the generation layer 513, high-brightness light emission is possible while maintaining a low current density. This enables the realization of even longer-lasting elements. Furthermore, it allows for low-voltage operation and low power consumption of light-emitting elements. The device can be realized.

[0144] Furthermore, by making the light-emitting color of each light-emitting unit different, the entire light-emitting device... This allows you to obtain light emission of the desired color. For example, a light emission device having two light emission units In the vise, the first light-emitting unit emits red and green light, and the second light-emitting unit emits blue light. By obtaining color, it is also possible to obtain a light-emitting device that emits white light as a whole. Yes, there is. Furthermore, an example of a light-emitting device configuration in which three or more light-emitting units are stacked is: The first light-emitting unit has a first blue light-emitting layer, and the second light-emitting unit has a yellow or yellowish-green light-emitting layer. The third light-emitting unit has a colored light-emitting layer and a red light-emitting layer, and the third light-emitting unit has a second blue light-emitting layer. This can be a tandem type device. This tandem type device is the above-mentioned light-emitting device Similar to the chair, it can emit white light.

[0145] Furthermore, the EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512 and Each layer, such as the charge generation layer, and the electrodes are, for example, deposited by methods such as vapor deposition (including vacuum deposition) and droplet ejection ( It can be formed using methods such as inkjet printing, coating, and gravure printing. They can be used. Also, they include low molecular weight materials, medium molecular weight materials (including oligomers and dendrimers), and Alternatively, it may contain polymer materials.

[0146] (Embodiment 3) In this embodiment, light emission using the light-emitting device described in Embodiment 1 and Embodiment 2 is demonstrated. Let me explain the device.

[0147] In this embodiment, the light-emitting device described in Embodiment 1 and Embodiment 2 is used for fabrication. The light-emitting device described will be explained using Figure 4. Figure 4(A) shows the light-emitting device. The top view, Figure 4(B), is a cross-sectional view of Figure 4(A) cut along lines AB and CD. This light emission The device controls the light emission of the light-emitting device, and the drive circuit section (source) is shown by the dotted line. It includes a line drive circuit (601), a pixel section (602), and a drive circuit section (gate line drive circuit) (603). Furthermore, 604 is the sealing substrate, and 605 is the sealing material, and the inside surrounded by the sealing material 605 This is space 607.

[0148] The routing wire 608 is input to the source line drive circuit 601 and the gate line drive circuit 603. FPC (Flexible Printed Circuit) is a wiring system for transmitting signals and serves as an external input terminal. (Input circuit) 609 receives video signals, clock signals, start signals, reset signals, etc. Receive. Note that only the FPC is shown in the diagram here, but this FPC has a print distribution A wire substrate (PWB) may be attached. The light-emitting device in this specification is a light-emitting device This includes not only the main unit but also the state in which the FPC or PWB is attached to it. ru.

[0149] Next, the cross-sectional structure will be explained using Figure 4(B). The drive circuit section is located on the element substrate 610. And a pixel section is formed, but here, the source line drive circuit 601 which is the drive circuit section and One pixel in the pixel section 602 is shown.

[0150] The element substrate 610 is a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, etc. FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fiber) It is made using a plastic substrate made of fluoride, polyester, or acrylic. That's all you need to do.

[0151] The structure of transistors used in pixels and driving circuits is not particularly limited. For example, inverse staggered It can be a type of transistor or a staggered transistor. Also, top Either a gate-type transistor or a bottom-gate transistor is acceptable. The semiconductor material is not particularly limited, and examples include silicon, germanium, silicon carbide, nitride Gallium can be used, or an In-Ga-Zn metal oxide can be used. An oxide semiconductor containing at least one of the elements, such as zinc, gallium, and zinc, may also be used.

[0152] The crystallinity of semiconductor materials used in transistors is not particularly limited; amorphous semiconductors, Crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with a crystalline region in part) Any semiconductor having the properties of [the semiconductor material] may be used. If a semiconductor having crystalline properties is used, transients may occur. This is preferable because it suppresses the deterioration of the stanic characteristics.

[0153] Here, in addition to the transistors provided in the pixels and driving circuits mentioned above, the touch sensors and the like described later are also included. It is preferable to use oxide semiconductors for semiconductor devices such as transistors. It is particularly preferable to use oxide semiconductors with a wider band gap than silicon. By using an oxide semiconductor with a wider band gap than Ricon, the off state of the transistor can be controlled. The current in this state can be reduced.

[0154] The above oxide semiconductor preferably contains at least indium (In) or zinc (Zn). It is also In-M-Zn oxides (where M is Al, Ti, Ga, Ge, Y, Zr, Sn, It is an oxide semiconductor containing an oxide (such as a metal like La, Ce, or Hf). It is preferable.

[0155] Herein, an oxide semiconductor that can be used in one aspect of the present invention will be described below. .

[0156] Oxide semiconductors are divided 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 ali gned crystalline oxide semiconductor), polycrystalline crystalline oxide semiconductor, nc-OS (nano crystalline oxide sem iconductor), pseudo-amorphous oxide semiconductor (a-like OS: amorph (Amorphous-like oxide semiconductor), and amorphous oxide semiconductor It contains conductors, etc.

[0157] CAAC-OS has c-axis orientation and multiple nanocrystals are linked in the ab-plane direction. Furthermore, it has a distorted crystal structure. Note that distortion refers to the region where multiple nanocrystals are connected. Within the region, between a region with aligned lattice arrangements and another region with aligned lattice arrangements, This refers to the part where the direction has changed.

[0158] Nanocrystals are based on a hexagonal structure, but they are not necessarily regular hexagons; they can also be non-regular hexagonal. Yes, it exists. Furthermore, the distortion may have lattice arrangements such as pentagons and heptagons. Furthermore, in CAAC-OS, even near strain, clear grain boundaries (grain bounds) are present. It is difficult to confirm (also called Dally) the crystal grains. In other words, due to the distortion of the lattice arrangement, It can be seen that the formation of the boundary is suppressed. This is because CAAC-OS is in the ab-plane direction. The oxygen atoms are not densely arranged, and the substitution of metal elements reduces the bond distance between atoms. This is because distortion can be tolerated through changes and other processes.

[0159] Furthermore, CAAC-OS consists of a layer containing indium and oxygen (hereinafter referred to as the In layer), and elements A layered crystalline structure in which layers containing M, zinc, and oxygen (hereinafter referred to as (M,Zn) layers) are stacked. It tends to have a layered structure (also called a structure). Furthermore, indium and element M are substituted for each other. It is possible, and if element M in the (M,Zn) layer is replaced with indium, then (In,M,Zn) It can also be represented as a layer. Furthermore, if the indium in the In layer is substituted with element M, then (In,M It can also be represented as a layer.

[0160] CAAC-OS is a highly crystalline oxide semiconductor. On the other hand, CAAC-OS has a clear bond. Because it is difficult to confirm grain boundaries, a decrease in electron mobility caused by grain boundaries is less likely to occur. It can be said that... Furthermore, the crystallinity of oxide semiconductors decreases due to the inclusion of impurities and the generation of defects. Because this can occur, CAAC-OS may contain impurities or defects (oxygen deficiencies (V O :oxygen It can also be described as an oxide semiconductor with low vacancy (also called CAA). Therefore, CAA Oxide semiconductors containing C-OS exhibit stable physical properties. Therefore, CAAC-OS The oxide semiconductors it possesses are highly heat-resistant and reliable.

[0161] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially between 1 nm and 3 nm). It has periodicity in the atomic arrangement in the region of less than nm. Furthermore, nc-OS has different nanometers. No regularity in crystal orientation is observed between crystals. Therefore, no orientation is observed throughout the entire film. Therefore, depending on the analysis method, nc-OS can be classified as a-like OS or amorphous oxide semiconductor. It can sometimes be difficult to distinguish between them.

[0162] Furthermore, indium is a type of oxide semiconductor containing indium, gallium, and zinc. Um-gallium-zinc oxide (hereinafter referred to as IGZO) is stable when formed into the nanocrystals described above. It may take on a structure. In particular, IGZO tends to have difficulty growing crystals in the atmosphere. Smaller crystals (for example) are preferable to larger crystals (here, crystals of a few millimeters or a few centimeters). In some cases, using the aforementioned nanocrystal structure may result in greater structural stability.

[0163] a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. It is a conductor. a-like OS has porous or low-density regions. That is, a-li ke OS has lower crystallinity compared to nc-OS and CAAC-OS.

[0164] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and nc -OS and CAAC-OS may have two or more types.

[0165] In addition to the oxide semiconductors mentioned above, CAC (Cloud-Aligned Comp You may also use osite)-OS.

[0166] CAC-OS refers to a material that possesses both conductive and insulating properties in some parts. Furthermore, the material as a whole possesses semiconductor functionality. Note that CAC-OS is used in transistors. When used in semiconductor layers, the conductive function is to allow electrons (or holes) that act as carriers to flow. The function of insulation is the function of preventing the flow of electrons, which act as carriers. The function of conductivity is... By having the insulating function and the other function work complementaryly, a switching function is achieved. The function to turn CAC-OS on / off can be added to CAC-OS. By separating each function, it is possible to maximize the performance of both.

[0167] Furthermore, CAC-OS has conductive regions and insulating regions. The conductive region is the conductive region described above. It has electrical properties, and the insulating region has the aforementioned insulating properties. Furthermore, in the material In some cases, the conductive region and the insulating region are separated at the nanoparticle level. The electrically conductive region and the insulating region may be unevenly distributed within the material. In some cases, the surrounding area may appear blurred and connected in a cloud-like manner.

[0168] Furthermore, in CAC-OS, the conductive region and the insulating region are each 0.5 nm or greater. In the case where 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.

[0169] Furthermore, CAC-OS is composed of components with different band gaps. For example, CAC-OS consists of a component with a wide gap due to the insulating region and a component that occurs in the conductive region. It is composed of a component having a narrow gap due to and . In this configuration, the carrier When flowing, the carrier mainly flows in the component with a narrow gap. Components with gaps act complementaryly with components with wide gaps, and narrow gaps In conjunction with the component having a gap, the carrier also flows to the component having a wide gap. When the above CAC-OS is used in the channel formation region of a transistor, the transistor In the ON state, a high current driving force, i.e., a large ON current and high field effect mobility are obtained. It is possible.

[0170] In other words, CAC-OS is a matrix composite. , or metal matrix composite and It can also be referred to as such.

[0171] By using the aforementioned oxide semiconductor material as the semiconductor layer, fluctuations in electrical properties are suppressed, and reliability This enables the creation of highly reliable transistors.

[0172] Furthermore, due to its low off-current, the transistor having the aforementioned semiconductor layer can be used to... This makes it possible to retain the charge stored in the capacity over a long period of time. By applying a generator to each pixel, the gradation of the image displayed in each display area is maintained while driving It also becomes possible to shut down the circuit. As a result, it is possible to realize electronic devices with extremely reduced power consumption. It can be expressed.

[0173] It is preferable to provide an undercoat to stabilize the characteristics of the transistor. The undercoat may be: Inorganic silicon oxide films, silicon nitride films, silicon oxide-nitride films, silicon nitride-oxide films, etc. It can be fabricated using an insulating film, either as a single layer or in a multilayer configuration. The underlayer is fabricated by sputtering. CVD (Chemical Vapor Deposition) method (Plasma CVD method) , thermal CVD method, MOCVD (Metal Organic CVD) method, ALD ( Formed using methods such as Atomic Layer Deposition, coating, and printing. Yes, it is possible. However, a base coat does not need to be applied unless necessary.

[0174] Note that FET623 is one of the transistors formed in the drive circuit section 601. Furthermore, the drive circuit is formed using various CMOS, PMOS, or NMOS circuits. This is sufficient. Furthermore, this embodiment shows a driver-integrated type in which the drive circuit is formed on the substrate. However, this is not always necessary, and the drive circuit can be formed externally rather than on the circuit board. .

[0175] Furthermore, the pixel section 602 includes a switching FET 611 and a current control FET 612 and its drive It is formed by multiple pixels, including an anode 613 electrically connected to the rain, The pixel unit may also be a combination of three or more FETs and a capacitive element.

[0176] Furthermore, an insulator 614 is formed covering the end of the anode 613. Here, a positive type sensor It can be formed by using light-sensitive acrylic.

[0177] Furthermore, in order to ensure good coverage of the EL layer and other layers formed later, the upper end of the insulator 614 is Alternatively, a curved surface with curvature is formed at the lower end. For example, the material of the insulator 614 and When a positive-type photosensitive acrylic is used, the radius of curvature (0.) is only at the upper end of the insulator 614. It is preferable to have a curved surface having a thickness of 2 μm to 3 μm. Also, as the insulator 614, Either a negative-type or positive-type photosensitive resin can be used.

[0178] An EL layer 616 and a cathode 617 are formed on the anode 613, respectively. Therefore, it is desirable to use a material with a large work function for the anode 613. For example, an ITO film, or an indium tin oxide film containing silicon, 2-20 wt% oxidation Indium oxide film containing zinc, titanium nitride film, chromium film, tungsten film, Zn film, Pt In addition to single-layer films such as membranes, lamination of titanium nitride films and films mainly composed of aluminum, titanium nitride A three-layer structure consisting of a film, a film mainly composed of aluminum, and a titanium nitride film can be used. Furthermore, a laminated structure results in low resistance as wiring and good ohmic contact. Furthermore, it can be used as an anode.

[0179] Furthermore, the EL layer 616 was coated using a vapor deposition method with a vapor deposition mask, an inkjet method, and a spin coating method. It is formed by various methods such as the above. The EL layer 616 is formed by Embodiment 1 and Embodiment 2 It includes the configuration described above. Furthermore, other materials constituting the EL layer 616 include: It may be a low-molecular-weight compound or a high-molecular-weight compound (including oligomers and dendrimers). .

[0180] Furthermore, the material used for the cathode 617 formed on the EL layer 616 has a small work function. Materials (Al, Mg, Li, Ca, or alloys and compounds thereof (MgAg, MgIn, It is preferable to use AlLi, etc. Furthermore, the light generated in the EL layer 616 is directed to the cathode 617 When allowing light to pass through, the cathode 617 consists of a thin metal film and a transparent conductive film (I TO, indium oxide containing 2-20 wt% zinc oxide, and indium tin containing silicon. It is preferable to use lamination with oxides (such as zinc oxide (ZnO)).

[0181] The anode 613, EL layer 616, and cathode 617 form the light-emitting device. The light-emitting device is the light-emitting device described in Embodiment 1 and Embodiment 2. Oh, the pixel section is made up of multiple light-emitting devices, but the light emission in this embodiment The apparatus includes the light-emitting device described in Embodiment 1 and Embodiment 2, and other components. It may include both of the light-emitting devices.

[0182] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, A light-emitting device is placed in the space 607 surrounded by the sub-substrate 610, the sealing substrate 604, and the sealing material 605. The structure is equipped with chair 618. Furthermore, the space 607 is filled with filler material. In addition to cases where inert gases (such as nitrogen or argon) are used for filling, there are also cases where sealing materials are used for filling. There are also cases where a recess is formed in the sealing substrate and a desiccant is placed there to prevent deterioration due to moisture. This configuration is preferable because it can suppress oxidation.

[0183] Furthermore, it is preferable to use epoxy resin or glass frit for the sealing material 605. These materials should ideally be as impermeable to moisture and oxygen as possible. In addition to glass substrates and quartz substrates, other materials can be used for the encapsulating substrate 604, such as FRP (Fiber Reinforced Plastic). reinforced plastics, PVF (polyvinyl fluoride), polyester A plastic substrate made of tel or acrylic can be used.

[0184] Although not shown in Figure 4, a protective film may be provided on the cathode. The protective film may be an organic resin film or an inorganic film. It can be formed with an insulating film. Also, a protective film can be made to cover the exposed portion of the sealing material 605. It may be formed. Also, the protective film may be on the surface and sides of the pair of substrates, a sealing layer, an insulating layer, It can be installed to cover exposed sides such as those shown.

[0185] The protective film can be made of a material that is impermeable to impurities such as water. This effectively suppresses the diffusion of impurities such as these from the outside to the inside.

[0186] Materials that make up the protective film include oxides, nitrides, fluorides, sulfides, ternary compounds, and metals. Alternatively, polymers can be used, for example, aluminum oxide, hafnium oxide, etc. Phenium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide Titanium dioxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide cerium oxide, scandium oxide, erbium oxide, vanadium oxide, or indi oxide Materials containing um, etc., as well as aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, nitrogen Includes titanium dioxide, 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 oxides Strontium-containing sulfides, erbium and aluminum-containing oxides, and Materials containing oxides, etc., including lium and zirconium can be used.

[0187] The protective film can be formed using a film deposition method that provides good step coverage. This is preferable. One such method is atomic layer deposition (ALD). There is a deposition method. Protecting materials that can be formed using the ALD method. It is preferable to use it for membranes. By using the ALD method, a dense membrane can be created with cracks and pinholes. A protective film can be formed with reduced defects or with a uniform thickness. This reduces the damage inflicted on the processed material when forming a protective film.

[0188] For example, by forming a protective film using the ALD method, surfaces with complex uneven shapes, or taps can be formed. A uniform and low-defect protective film can be formed on the top, sides, and back surfaces of the panel. .

[0189] As described above, the light-emitting devices described in Embodiments 1 and 2 are used to manufacture the light-emitting devices. A light-emitting device can be obtained.

[0190] The light-emitting device in this embodiment is the same as the light-emitting device described in Embodiment 1 and Embodiment 2. Because it uses a specific material, a light-emitting device with good characteristics can be obtained. Specifically, The light-emitting devices described in Embodiment 1 and Embodiment 2 are long-life light-emitting devices. Therefore, a highly reliable light-emitting device can be made. Also, Embodiment 1 and Embodiment Because the light-emitting device using the light-emitting device described in 2 has good luminous efficiency, it consumes little power. It can be used as an optical device.

[0191] Figure 5 shows a light-emitting device that emits white light, with a colored layer (color filter) provided. This shows an example of a light-emitting device that has been made full-color. Figure 5(A) shows substrate 1001, base Insulating film 1002, gate insulating film 1003, gate electrodes 1006, 1007, 1008, Interlayer insulating film 1020, second interlayer insulating film 1021, peripheral portion 1042, pixel portion 1040 , drive circuit section 1041, anodes 1024W, 1024R, 1024G, 10 24B, partition wall 1025, EL layer 1028, cathode of light-emitting device 1029, sealing substrate 103 1. The sealing material 1032 and other components are shown in the diagram.

[0192] Furthermore, Figure 5(A) shows the colored layers (red colored layer 1034R, green colored layer 1034G, blue The colored layer 1034B is provided on a transparent substrate 1033. Also, the black matrix 1 A 035 layer may be further provided. Transparent substrate 1 provided with a colored layer and a black matrix. 033 is aligned and fixed to substrate 1001. Note that the colored layer and black matrix Kus 1035 is covered with an overcoat layer 1036. Also, in Figure 5(A) This consists of a light-emitting layer that allows light to escape to the outside without passing through the colored layers, and a layer that allows light to escape to the outside by passing through the colored layers of each color. There is a light-emitting layer, and light that does not pass through the colored layer is white, while light that passes through the colored layer is red, green, and blue. Therefore, images can be represented using four colored pixels.

[0193] Figure 5(B) shows the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer Example of forming layer 1034B) between the gate insulating film 1003 and the first interlayer insulating film 1020. This was shown. Thus, the colored layer is provided between the substrate 1001 and the sealing substrate 1031. That's good too.

[0194] Furthermore, in the light-emitting device described above, light is taken to the substrate 1001 side on which the FET is formed. Although a light-emitting device with a bottom-emission structure was used, the light emission was taken from the sealing substrate 1031 side. It can also be used as a light-emitting device with a projection structure (top emission type). A cross-sectional view of the light-emitting device is shown in Figure 6. In this case, the substrate 1001 is a substrate that does not transmit light. This can be done. Until the connecting electrode that connects the FET and the anode of the light-emitting device is fabricated, the bottle It is formed in the same way as a muemission-type light-emitting device. Then, the third interlayer insulating film 1037 is electrically... It is formed covering pole 1022. This insulating film may also play a planarization role. Third layer The interlayer insulating film 1037 is formed using the same material as the second interlayer insulating film, as well as other known materials. It is possible.

[0195] The anodes 1024W, 1024R, 1024G, and 1024B of the light-emitting devices are referred to here as anodes. However, it is also acceptable to form it as a cathode. Furthermore, a top-emission type emission as shown in Figure 6... In the case of an optical device, it is preferable to use the anode as a reflective electrode. The configuration of the EL layer 1028 is as follows: The configuration is as described in Embodiment 1 and Embodiment 2 as the EL layer 103, and The element structure is designed to produce white light emission.

[0196] In the top emission structure shown in Figure 6, the colored layer (red colored layer 1034R, green colored layer) The sealing is performed using a sealing substrate 1031 having a color layer 1034G and a blue colored layer 1034B. This can be done. The encapsulation substrate 1031 has a black matrix positioned between the pixels. 1035 may be provided. Colored layer (red colored layer 1034R, green colored layer 1034G, The blue colored layer (1034B) and the black matrix are formed by the overcoat layer (1036). It may be covered. The sealing substrate 1031 shall be a light-transmitting substrate. Furthermore, while we have shown an example of full-color display using four colors—red, green, blue, and white—this is not particularly limited. Alternatively, full-color display may be performed using four colors: red, yellow, green, and blue, or three colors: red, green, and blue.

[0197] In top-emission type light-emitting devices, a microcavity structure can be suitably applied. A light-emitting device having a microcavity structure has a reflective electrode as the anode and a semi-transparent / semi-reflective cathode. This is obtained by using a ray electrode. Between the reflective electrode and the semitransmissive / semi-reflective electrode, there is at least It has an EL layer and at least an emissive layer that forms an emissive region.

[0198] The reflective electrode has a visible light reflectance of 40% to 100%, preferably 70% to 100%. It is %, and its resistivity is 1 × 10⁻⁶. -2 Assume the membrane is less than Ωcm in diameter. Also, semipermeable... The semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%. , and its resistivity is 1 × 10 -2 Assume the membrane is less than Ωcm in diameter.

[0199] The light emitted from the light-emitting layer contained in the EL layer is reflected by the reflective electrode and the semi-transmitting / semi-reflective electrode. It is reflected and resonates.

[0200] The light-emitting device changes the thickness of the transparent conductive film, the aforementioned composite material, the carrier transport material, etc. This allows us to change the optical distance between the reflective electrode and the semitransmissive / semi-reflective electrode. Furthermore, the light of the resonant wavelength is amplified between the reflective electrode and the semitransmissive / semi-reflective electrode, causing resonance. It can attenuate light of wavelengths that are not present.

[0201] Furthermore, the light reflected back by the reflective electrode (the first reflected light) is semi-transmitted from the light-emitting layer. • Because it causes significant interference with the light (first incident light) that directly enters the semi-reflecting electrode, the reflective electrode and The optical distance of the light-emitting layer is (2n-1)λ / 4 (where n is a natural number greater than or equal to 1, and λ is amplified). It is preferable to adjust the wavelength of the emitted light. By adjusting the optical distance, the first By aligning the phase of the reflected light and the first incident light, the light emitted from the light-emitting layer can be further amplified. ru.

[0202] Furthermore, in the above configuration, even if the EL layer has a structure with multiple light-emitting layers, a single light-emitting layer The structure may have layers, for example, in combination with the configuration of the tandem light-emitting device described above. In addition, multiple EL layers are provided in a single light-emitting device with a charge generation layer in between, and each EL This can also be applied to configurations in which one or more light-emitting layers are formed in a layer.

[0203] Having a microcavity structure enhances the emission intensity in the front direction at specific wavelengths. This makes it possible to reduce power consumption. Furthermore, the four sub-colors red, yellow, green, and blue are used. In the case of a light-emitting device that displays images as is, in addition to the brightness enhancement effect of yellow light emission, all sub-pixels By applying a microcavity structure tailored to the wavelength of each color, a light-emitting device with excellent characteristics can be produced. It can be placed there.

[0204] The light-emitting device in this embodiment is the same as the light-emitting device described in Embodiment 1 and Embodiment 2. Because it uses a specific material, a light-emitting device with good characteristics can be obtained. Specifically, The light-emitting devices described in Embodiment 1 and Embodiment 2 are long-life light-emitting devices. Therefore, a highly reliable light-emitting device can be made. Also, Embodiment 1 and Embodiment Because the light-emitting device using the light-emitting device described in 2 has good luminous efficiency, it consumes little power. It can be used as an optical device.

[0205] Up to this point, we have explained active-matrix light-emitting devices, but from here on we will discuss passive devices. A matrix-type light-emitting device will be described. Figure 7 shows a passive light-emitting device fabricated by applying the present invention. This shows a matrix-type light-emitting device. Figure 7(A) is a perspective view showing the light-emitting device, Figure 7( B) is a cross-sectional view obtained by cutting Figure 7(A) along the XY line. In Figure 7, on the substrate 951, An EL layer 955 is provided between electrode 952 and electrode 956. The end of electrode 952 is It is covered with an insulating layer 953. And a partition layer 954 is provided on top of the insulating layer 953. The side walls of the partition layer 954, as they approach the substrate surface, have a gap between one side wall and the other side wall. It has a slope that narrows as the partition becomes narrower. In other words, the cross-section of the partition wall layer 954 in the short-side direction is It is a shape, and the bottom edge (which 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 edge (the edge that faces the same direction as the surface direction of the insulating layer 953 and does not come into contact with the insulating layer 953). It is shorter than that. In this way, by providing the partition layer 954, light emission devices caused by static electricity, etc. This can prevent defects in the system. Furthermore, it can also be implemented in passive matrix type light-emitting devices. The light-emitting device described in Embodiment 1 and Embodiment 2 is used, and is a highly reliable light-emitting device It can be used as a light-emitting device with low power consumption.

[0206] The light-emitting device described above consists of numerous tiny light-emitting devices arranged in a matrix. Because these can be controlled, it can be suitably used as a display device for representing images. It is a light-emitting device.

[0207] Furthermore, this embodiment can be freely combined with other embodiments.

[0208] (Embodiment 4) In this embodiment, the light-emitting devices described in Embodiment 1 and Embodiment 2 are used as an illumination device. An example of its use will be explained with reference to Figure 8. Figure 8(B) is a top view of the lighting device, and Figure 8(A) is a top view of the lighting device. ) is a cross-sectional view of ef in Figure 8(B).

[0209] In this embodiment, the lighting device has an anode 4 on a translucent substrate 400 which is a support. 01 is formed. The anode 401 corresponds to the anode 101 in Embodiment 2. Anode When light is extracted from the 401 side, the anode 401 is formed from a translucent material.

[0210] A pad 412 for supplying voltage to the cathode 404 is formed on the substrate 400.

[0211] An EL layer 403 is formed on the anode 401. The EL layer 403 is the same as in Embodiment 1 and the actual Configuration of the EL layer 103 in the second form of application, or light-emitting units 511, 512 and charge generation This corresponds to a configuration including layer 513, etc. For details on these configurations, please refer to the relevant description. I want to be treated that way.

[0212] The cathode 404 is formed by covering the EL layer 403. The cathode 404 is the cathode 1 in Embodiment 2. This corresponds to 02. When light is extracted from the anode 401 side, the cathode 404 is made of a material with high reflectivity. It is formed by the cathode 404 being connected to the pad 412, thereby supplying voltage. It can be done.

[0213] The above describes the light-emitting device having an anode 401, an EL layer 403, and a cathode 404 in this embodiment. The lighting device shown is equipped with the light-emitting device. The light-emitting device is a light-emitting device with high luminous efficiency. Therefore, the lighting device in this embodiment can be a lighting device with low power consumption.

[0214] The substrate 400 on which the light-emitting device having the above configuration is formed and the sealing substrate 407 are sealed The lighting device is completed by fixing and sealing it using materials 405 and 406. Either 405 or 406 is acceptable. Also, the inner sealant 406 (Figure 8 (B) (Not shown) A desiccant can also be mixed in, which allows it to absorb moisture. This leads to improved reliability.

[0215] Furthermore, the pad 412 and a portion of the anode 401 are extended outside the sealing materials 405 and 406. This allows it to be used as an external input terminal. Furthermore, a converter or similar device can be mounted on top of it. An IC chip 420 or similar may be provided.

[0216] As described above, the lighting device described in this embodiment has an EL element as described in Embodiment 1 and Embodiment 2. The light-emitting device described is used, resulting in a highly reliable light-emitting device. Furthermore, This allows for a light-emitting device with low power consumption.

[0217] (Embodiment 5) In this embodiment, the light-emitting device described in Embodiments 1 and 2 is used as a part thereof. Examples of electronic devices to be included will be described. The light-emitting devices described in Embodiment 1 and Embodiment 2 The chair is a reliable light-emitting device with a good lifespan. As a result, this embodiment The electronic device described can be an electronic device having a highly reliable light-emitting part.

[0218] Examples of electronic devices to which the above-mentioned light-emitting device is applied include television equipment (televisions, and (Also called a television receiver), monitors for computers, digital cameras, digital cameras Digital video cameras, digital photo frames, mobile phones (both mobile phones and mobile phone devices) (Examples include) portable game consoles, personal digital assistants, audio playback devices, and large game machines such as pachinko machines. These are some examples. Specific examples of these electronic devices are shown below.

[0219] Figure 9(A) shows an example of a television system. The television system has a housing 710 The display unit 7103 is incorporated into part 1. Also, the housing is connected by the stand 7105. This shows the configuration supporting 7101. The display unit 7103 can display video. The display unit 7103 is capable of displaying the light-emitting devices described in Embodiment 1 and Embodiment 2. It is arranged in a matrix.

[0220] The television equipment can be operated using the control switches on the housing 7101 or a separate remote control. This can be done using the device 7110. The remote control device 7110 has an operation key 7109. This allows you to control the channel and volume, and the video displayed on the display unit 7103 It can be operated. Also, the remote control unit 7110 A display unit 7107 that displays the information output from the unit may also be provided.

[0221] The television system shall consist of a receiver, modem, etc. It can receive television broadcasts, and also communicate via wired or wireless connection through a modem. By connecting to a network, one-way (sender to receiver) or two-way (sender to receiver) communication is possible. It is also possible to communicate information between recipients, or between recipients themselves.

[0222] Figure 9(B1) is a computer, consisting of the main unit 7201, the casing 7202, the display unit 7203, and a key - Includes board 7204, external connection port 7205, pointing device 7206, etc. Furthermore, this computer uses the light-emitting devices described in Embodiment 1 and Embodiment 2. It is manufactured by arranging them in a matrix and using them in the display unit 7203. Figure 9(B1) The computer may take the form shown in Figure 9(B2). The second display unit 7 is used instead of the keyboard 7204 and pointing device 7206. 210 is provided. The second display unit 7210 is a touch panel type, and the second Input is performed by operating the input display shown on the display unit 7210 with a finger or a special pen. This can be done. In addition, the second display unit 7210 can display not only input information but also other images. It is also possible to display an image. Furthermore, the display unit 7203 may also be a touch panel. Because the two screens are connected by a hinge, the screens can get scratched when storing or transporting the device. This also prevents problems such as damage from occurring.

[0223] Figure 9(C) shows an example of a mobile terminal. The mobile phone is incorporated into the housing 7401. In addition to the display unit 7402, there are operation buttons 7403, an external connection port 7404, and a speaker 740 5. It is equipped with a microphone 7406, etc. Note that the mobile phone is the same as in Embodiment 1 and the embodiment. The display unit 7402 is made by arranging the light-emitting devices described in Embodiment 2 in a matrix. It is.

[0224] The mobile terminal shown in Figure 9(C) allows users to input information by touching the display unit 7402 with their fingers or other objects. It can also be configured to allow for making phone calls or composing emails. Operations such as this can be performed by touching the display unit 7402 with a finger or the like.

[0225] The display unit 7402 has three main modes. The first is a display that primarily displays images. The first mode is display mode, the second is input mode which is mainly for inputting information such as characters. The third is display mode. This is a display + input mode, which is a combination of two modes: display mode and input mode.

[0226] For example, when making a phone call or composing an email, the display unit 7402 is used for text input. In this case, the primary text input mode should be used, and you should perform the input operation for the characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display unit 7402. It seems so.

[0227] Furthermore, the mobile device has sensors inside that detect tilt, such as a gyroscope and an accelerometer. By installing the device, the orientation of the mobile terminal (portrait or landscape) is determined, and the screen display of the display unit 7402 is displayed accordingly. The display can be set to switch automatically.

[0228] Furthermore, screen modes can be switched by touching the display unit 7402 or by operating the housing 7401. This is done by operating button 7403. Also, the type of image displayed on display unit 7402 Therefore, it is also possible to switch between them. For example, the image signal displayed on the display unit is a video signal. Switch to display mode if it's data, or to input mode if it's text data.

[0229] Furthermore, in input mode, the signal detected by the optical sensor of the display unit 7402 is detected and displayed If there is no input via touch operation on unit 7402 for a certain period of time, the screen mode will be changed to input mode. You may also control the system to switch from that display mode to a different mode.

[0230] The display unit 7402 can also function as an image sensor. For example, the display unit 74 By touching device 02 with the palm or fingers, the user can be authenticated by capturing images of their palm print, fingerprints, etc. Furthermore, the display unit may have a backlight that emits near-infrared light or a sensing light that emits near-infrared light. Using the appropriate source, it is also possible to image finger veins, palmar veins, and other veins.

[0231] The configuration shown in this embodiment is a combination of the configurations shown in Embodiments 1 to 4 as appropriate. They can be used together.

[0232] As described above, the light-emitting device equipped with the light-emitting device described in Embodiment 1 and Embodiment 2 is suitable for Its range of applications is extremely wide, and this light-emitting device can be applied to electronic equipment in all fields. By using the light-emitting devices described in Embodiment 1 and Embodiment 2, reliability can be improved. You can obtain high-end electronic devices.

[0233] Figure 10(A) is a schematic diagram showing an example of a cleaning robot.

[0234] The cleaning robot 5100 has a display 5101 located on the top and multiple displays located on the sides. It has several cameras 5102, brushes 5103, and operation buttons 5104. However, the underside of the 5100 cleaning robot is equipped with wheels, a suction port, etc. The 5100 robot also includes an infrared sensor, ultrasonic sensor, acceleration sensor, and piezo sensor. It is equipped with various sensors such as optical sensors and gyro sensors. Also, the cleaning robot 5 Unit 100 is equipped with wireless communication means.

[0235] The cleaning robot 5100 moves autonomously, detects the dirt 5120, and uses the suction port located on its underside to... It can then vacuum up the dust.

[0236] Furthermore, the cleaning robot 5100 analyzes images captured by the camera 5102, and detects walls, furniture, or It can determine the presence or absence of obstacles such as steps. Furthermore, image analysis can detect wiring and other obstacles. If an object that may become entangled in brush 5103 is detected, the rotation of brush 5103 will be stopped. can.

[0237] The display 5101 displays information such as the battery level and the amount of dust collected. This is possible. The path taken by the cleaning robot 5100 can be displayed on the display 5101. Good. Also, the display 5101 is a touch panel, and the operation buttons 5104 are on the display. It may also be provided at Ray 5101.

[0238] The cleaning robot 5100 can communicate with portable electronic devices 5140 such as smartphones. Yes, it is possible. Images captured by camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the 5100 cleaning robot can know what's happening in the room even when they're away from home. It is possible to display the information on the display 5101 on portable electronic devices such as smartphones. You can also check it there.

[0239] A light-emitting device according to one aspect of the present invention can be used in a display 5101.

[0240] The robot 2100 shown in Figure 10(B) consists of a computing unit 2110, an illuminance sensor 2101, and a microcontroller. Crossphone 2102, upper camera 2103, speaker 2104, display 2105, It is equipped with a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0241] Microphone 2102 has the function of detecting the user's voice and ambient sounds, etc. Speaker 2104 has the function of emitting sound. Robot 2100 has a microphone Using the 2102 and speaker 2104, communication with the user is possible. It is possible.

[0242] The display 2105 has the function of displaying various information. The robot 2100 is The user can display the desired information on the display 2105. The 2105 may have a touch panel. Also, the display 2105 is removable. It can be any information terminal capable of charging, and by installing it in a fixed position on the robot 2100, And it enables the transfer of data.

[0243] The upper camera 2103 and lower camera 2106 are used to image the area around the robot 2100. It has the ability to detect obstacles. Furthermore, the obstacle sensor 2107 uses the moving mechanism 2108 to detect robot 210 Robot 21 can detect the presence or absence of obstacles in the direction of travel as it moves forward. 00 uses the upper camera 2103, the lower camera 2106 and the obstacle sensor 2107 The light-emitting device according to one aspect of the present invention can recognize its surroundings and move safely. It can be used in display 2105.

[0244] Figure 10(C) shows an example of a goggle-type display. For example, the components include the casing 5000, the display unit 5001, the speaker 5003, and the LED lamp 5004. , connection terminal 5006, sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotational speed) Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, electric current, voltage, power, (including functions for measuring radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), It includes an ICrophone 5008, a display unit 5002, a support unit 5012, an earphone 5013, etc. .

[0245] The light-emitting device according to one aspect of the present invention can be used in the display unit 5001 and the display unit 5002. .

[0246] Figure 11 shows the light-emitting devices described in Embodiments 1 and 2, which are used as lighting devices. This is an example of its use in a desk lamp. The desk lamp shown in Figure 11 consists of a housing 2001 and a light source 20 The device has 02, and the light source 2002 may be the lighting device described in Embodiment 3.

[0247] Figure 12 shows the light-emitting devices described in Embodiment 1 and Embodiment 2 in an indoor lighting device 3 This is an example of its use as 001. The light-emitting devices described in Embodiment 1 and Embodiment 2 Because it is a highly reliable light-emitting device, it can be used to create a highly reliable lighting system. Since the light-emitting devices described in Embodiments 1 and 2 can be made to have a large area, It can be used as a large-area lighting device. Furthermore, in Embodiments 1 and 2 Because the described light-emitting device is thin, it can be used as a miniaturized lighting device. Yes.

[0248] The light-emitting devices described in Embodiments 1 and 2 are used on the windshields and windows of automobiles. It can also be mounted on a dashboard. Figure 13 shows Embodiment 1 and Embodiment 2. This shows one embodiment of using the light-emitting device on the windshield or dashboard of an automobile. Display areas 5200 to 5203 are light-emitting devices as described in Embodiments 1 and 2. This is a display area provided using a vise.

[0249] Display area 5200 and display area 5201 are in an embodiment provided on the windshield of an automobile. This is a display device equipped with the light-emitting device described in Embodiment 1 and Embodiment 2. Embodiment 1 The light-emitting device described in Embodiment 2 is made by fabricating the anode and cathode with light-transmitting electrodes. This allows the display device to be made transparent, allowing the other side to be seen through, creating a so-called see-through display. Yes, it's possible. If it's a see-through display, it can be installed on a car's windshield. It can be installed without obstructing the view. Note that it requires transistors for operation, etc. When providing an organic transistor, an organic transistor made of organic semiconductor material or a transistor made of oxide semiconductor material may be used. It is best to use a transmissive transistor, such as a transistor.

[0250] The display area 5202 is provided in the pillar portion as described in Embodiments 1 and 2. This is a display device equipped with an optical device. The display area 5202 is an imaging device provided on the vehicle body. By displaying images from the steps, the view obstructed by the pillars can be compensated for. Similarly, the display area 5203 located on the dashboard is obstructed by the vehicle body. The field of view is obscured by displaying images from an imaging device installed on the outside of the vehicle, thereby reducing blind spots. This can supplement the unseen parts and enhance safety. Therefore, safety checks can be performed more naturally and without any sense of unease.

[0251] The display area 5203 can also display navigation information, speedometer, tachometer, etc. It can provide various information. The display items and other information can be adjusted as needed according to the user's preferences. The output can be changed. Note that this information is displayed in display area 5200 to display area 5 It can also be installed in 202. In addition, the display areas 5200 to 5203 are illuminated. It can also be used as a stand.

[0252] Figures 14(A) and (B) also show a foldable portable information terminal 5150. The portable information terminal 5150 consists of a housing 5151, a display area 5152, and a bendable portion 515 It has 3. Figure 14(A) shows the portable information terminal 5150 in its unfolded state. Figure 14( B) shows the portable information terminal in its folded state. The portable information terminal 5150 has a large display area Despite having a 5152mm field of view, it folds up compactly and is highly portable.

[0253] The display area 5152 can be folded in half by the bending portion 5153. Bending portion 515 3 consists of an expandable member and multiple support members, and when folded, the expandable The member stretches, and the bent portion 5153 has a radius of curvature of 2 mm or more, preferably 3 mm or more. It folds up.

[0254] Note that the display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). It may also be a device. The light-emitting device according to one aspect of the present invention can be used in the display area 5152. Cut.

[0255] Figures 15(A) to (C) also show a foldable portable information terminal 9310. Figure 15 (A) shows the portable information terminal 9310 in its unfolded state. Figure 15(B) shows the unfolded state or This shows the portable information terminal 9310 in an intermediate state, transitioning from one folded state to the other. Figure 15(C) shows the folded state of the personal digital assistant 9310. Personal digital assistant 9310 It offers excellent portability when folded and a seamless, wide display area when unfolded. This provides excellent readability in the display.

[0256] 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). It may also be an input / output device. In addition, the display panel 9311 is connected via the hinge 9313. By bending the two housings 9315, the mobile information terminal 9310 is unfolded. It can be reversibly transformed from a folded state. A light-emitting device according to one aspect of the present invention It can be used with the display panel 9311. [Examples]

[0257] In this embodiment, light-emitting devices 1 to 3 and comparative light-emitting devices according to one aspect of the present invention Let's describe chair 1. Light-emitting devices 1 to 3 and comparative light-emitting device 1. The structural formulas of the organic compounds used are shown below.

[0258] [ka]

[0259] (Method for fabricating light-emitting device 1) First, indium tin oxide (ITSO) containing silicon oxide is sputtered onto a glass substrate. A film was deposited using the 2-phase method to form the anode 101. The film thickness was 70 nm, and the electrode area was 2 The dimensions were set to mm x 2 mm.

[0260] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface is washed with water, and 2 After firing at 0°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0261] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0262] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. The substrate is fixed to a substrate holder provided inside the vapor deposition apparatus, and vapor deposition is carried out on the anode 101 using resistance heating. N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) is obtained by the bonding method. Benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and AL D-MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20170124) , such that the weight ratio is 1:0.1 (=BBABnf:ALD-MP001Q), 10n A hole injection layer 111 was formed by co-deposition.

[0263] Next, BBABnf is added to the hole injection layer 111 as the first hole transport layer 112-1. After deposition to a size of nm, the second hole transport layer 112-2 is formed using the above structural formula (ii). Represented as 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-cal) A hole transport layer 112 is formed by depositing a bazole (abbreviated as PCzN2) to a thickness of 10 nm. Success. Furthermore, the second hole transport layer 112-2 also functions as an electron blocking layer.

[0264] Next, the 9-(1-naphthyl)-10-[4-(2-naphthyl] represented by the above structural formula (iii) [Phthyl)phenyl]anthracene (abbreviation: 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) and a weight ratio of 1:0.015 (=αN-βNPAnth:3, A 25nm co-deposited layer (10PCA2Nbf(IV)-02) is formed to create the light-emitting layer 113. I did it.

[0265] Subsequently, on the light-emitting layer 113, 2-{4-[9,10-di(na) represented by the above structural formula (v) is applied. Phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimi Dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviated as Liq) and 1 are mixed in a weight ratio of 0.9:1 (=ZADN:Liq) After co-deposition at 2.5 nm, 12 layers were deposited so that the weight ratio was 1:0.9 (=ZADN:Liq). A 5nm co-deposited layer was used to form an electron transport layer 114.

[0266] After forming the electron transport layer 114, Liq is deposited to a thickness of 1 nm to form the electron injection layer 1 Forming 15, and then depositing aluminum to a thickness of 200 nm to create a cathode The light-emitting device 1 of this embodiment was fabricated by forming 102.

[0267] (Method for fabricating light-emitting device 2) The light-emitting device 2 has an electron transport layer 114 with a ZADN:Liq ratio of 0.7:1 (by weight). After co-depositing at 12.5nm, the weight ratio becomes 1:0.7 (=ZADN:Liq). The device was fabricated in the same manner as light-emitting device 1, except that it was formed by co-depositing 12.5 nm onto the surface.

[0268] (Method for fabricating light-emitting device 3) The light-emitting device 3 has an electron transport layer 114 with a ZADN:Liq ratio of 0.5:1 (by weight). After co-depositing at 12.5nm, the weight ratio becomes 1:0.5 (=ZADN:Liq). The device was fabricated in the same manner as light-emitting device 1, except that it was formed by co-depositing 12.5 nm onto the surface.

[0269] (Method for fabricating comparative light-emitting device 1) The comparative light-emitting device 1 has an electron transport layer 114 with a ZADN:Liq ratio of 1:1 (by weight). Aside from being formed by co-depositing at 25 nm, the device was fabricated in the same manner as light-emitting device 1.

[0270] The element structures of light-emitting devices 1 to 3 and comparative light-emitting device 1 are shown in the table below. Stop.

[0271] [Table 1]

[0272] Here, the HOMO level, LUMO level, and electric field strength of the organic compound used in this example [ The following table summarizes the electron mobility at a square root of 600 [V / cm].

[0273] [Table 2]

[0274] These light-emitting devices are placed in a glove box under a nitrogen atmosphere, and the light-emitting devices are exposed to the atmosphere. The process of sealing the element with a glass substrate to prevent exposure to sunlight (applying a sealing material around the element and sealing it) After UV treatment and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices are determined. Reliability was also measured. The measurements were taken at room temperature.

[0275] The brightness-current density characteristics of light-emitting devices 1 to 3 and comparative light-emitting device 1 are shown in the figure. Figure 16 shows the current efficiency-luminance characteristics, Figure 17 shows the luminance-voltage characteristics, and Figure 18 shows the current-voltage characteristics. Figure 19 shows the external quantum efficiency-luminance characteristics, Figure 20 shows the emission spectrum, and Figure 21 shows the emission spectrum. Light-emitting devices 1 to 3 and comparative light-emitting device 1: 1000 cd / m² 2 nearby The main characteristics of this are shown in Table 3.

[0276] [Table 3]

[0277] Figures 16 to 21 and Table 3 show one embodiment of the present invention: Light-emitting device 1 to Light-emitting device Device 3 and comparative light-emitting device 1 are blue light-emitting devices with good initial characteristics. Understood.

[0278] Furthermore, the current density is 50 mA / cm². 2 In this context, light-emitting devices 1 to 3 (in Figure 22, devices 1 to 3) and the operating time of the comparative light-emitting device 1 (comparative device 1 in Figure 22) A graph showing the change in brightness is shown in Figure 22. As shown in Figure 22, the light emission device of one embodiment of the present invention The light-emitting devices 1 to 3, which are vices, increase in brightness after being driven, and their brightness increases from the initial brightness. It can be seen that the brightness is high before gradually decreasing. In other words, there is a maximum on the degradation curve. It has points. Therefore, the drive is based on a low degradation state of about 2-5% degradation. We were able to significantly improve the lifespan. Also, the ratio of ZADN to Liq in the electron transport layer It was also discovered that the degree of brightness increase can be controlled by changing this setting. . [Examples]

[0279] In this embodiment, a light-emitting device 4 and a light-emitting device 5 according to one aspect of the present invention will be described. The structural formulas of the organic compounds used in light-emitting devices 4 and 5 are shown below.

[0280] [ka]

[0281] (Method for fabricating light-emitting devices 4 and 5) First, on a glass substrate, silver (Ag), palladium (Pd), and copper (Cu) are used as reflective electrodes. A 100 nm thick alloy film (Ag-Pd-Cu(APC) film) is formed by sputtering. After forming a thick film, indium tin oxide (ITSO) containing silicon oxide is spat as a transparent electrode. Anode 101 was formed by depositing a film with a thickness of 85 nm using the tarring method. The area is 4 mm 2 (2mm x 2mm)

[0282] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface is washed with water, and 2 After firing at 0°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0283] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0284] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. The substrate is fixed to a substrate holder provided inside the vapor deposition apparatus, and vapor deposition is carried out on the anode 101 using resistance heating. N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) is obtained by the bonding method. Benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and AL D-MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20170124) , so that the weight ratio is 1:0.05 (=BBABnf:ALD-MP001Q), 10 A hole injection layer 111 was formed by co-deposition at nm.

[0285] Next, BBABnf is added to the hole injection layer 111 as the first hole transport layer 112-1. After deposition to a size of nm, the second hole transport layer 112-2 is formed using the above structural formula (ii). Represented as 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-cal) A hole transport layer 112 is formed by depositing a bazole (abbreviated as PCzN2) to a thickness of 10 nm. Success. Furthermore, the second hole transport layer 112-2 also functions as an electron blocking layer.

[0286] Next, the 9-(1-naphthyl)-10-[4-(2-naphthyl] represented by the above structural formula (iii) [Phthyl)phenyl]anthracene (abbreviation: 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) and a weight ratio of 1:0.015 (=αN-βNPAnth:3, A 25nm co-deposited layer (10PCA2Nbf(IV)-02) is formed to create the light-emitting layer 113. I did it.

[0287] Subsequently, on the light-emitting layer 113, 2-{4-[9,10-di(na) represented by the above structural formula (v) is applied. Phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimi Dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviated as Liq) and 1 are mixed in a weight ratio of 0.7:1 (=ZADN:Liq) After co-deposition at 2.5 nm, 12 layers were deposited so that the weight ratio was 1:0.7 (=ZADN:Liq). An electron transport layer 114 was formed by co-depositing a 5nm layer.

[0288] After forming the electron transport layer 114, the volume ratio of silver (Ag) to magnesium (Mg) is set to 1:0 1. By depositing to a thickness of 15 nm, a cathode 102 is formed and the light-emitting device 4 is created. A light-emitting device 5 was fabricated. The cathode 102 has the function of reflecting light and the function of transmitting light. A semi-transparent / semi-reflective electrode having the ability, and the light-emitting device 4 and light-emitting device of this embodiment 5 is a top-emission element that extracts light from cathode 102. Also, on cathode 102 The above structural formula (vii) represents 1,3,5-tri(dibenzothiophen-4-yl Benzene (abbreviation: DBT3P-II) is deposited at an 80nm layer to improve extraction efficiency. ru.

[0289] The element structures of light-emitting devices 4 and 5 are summarized in the table below.

[0290] [Table 4]

[0291] Here, the HOMO level, LUMO level, and electric field strength of the organic compound used in this example [ The following table summarizes the electron mobility at a square root of 600 [V / cm].

[0292] [Table 5]

[0293] This light-emitting device is placed in a glove box under a nitrogen atmosphere, and the light-emitting device is exposed to the atmosphere. The process of sealing the element with a glass substrate to prevent exposure (applying a sealing material around the element and sealing it). After performing UV treatment and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices are determined. Reliability was measured. The measurements were taken at room temperature.

[0294] Figure 30 shows the luminance-current density characteristics of light-emitting devices 4 and 5, and the current efficiency-luminance characteristics. The characteristics are shown in Figure 31, the brightness-voltage characteristics in Figure 32, the current-voltage characteristics in Figure 33, and the external quantum efficiency. -Brightness characteristics are shown in Figure 34, and emission spectrum is shown in Figure 35. Also, the light-emitting device 4 and 5 1000 cd / m² optical devices 2 Table 6 shows the main characteristics of the vicinity.

[0295] [Table 6]

[0296] Figures 30 to 35 and Table 6 show one embodiment of the present invention: Light-emitting device 4 and light-emitting device S5 was found to be a blue light-emitting device with good characteristics.

[0297] Additionally, the initial brightness was set to 1450 cd / m². 2Operating time under the condition of constant current density Figure 36 shows a graph representing the change in brightness for [a certain value]. As shown in Figure 36, one aspect of the present invention Light-emitting devices 4 and 5, which are light-emitting devices, show an increase in brightness after operation and an initial It can be seen that the brightness is higher than the stated brightness before gradually decreasing. In other words, it is a degraded song. The line has a local maximum point. Because of this, even after 450 hours of operation, the initial brightness remains. It maintains 101% of its original capacity, significantly improving the drive life based on a minimal degradation state. It was done. [Examples]

[0298] In this embodiment, a light-emitting device 6 according to one aspect of the present invention will be described. The structural formulas of the organic compounds are shown below.

[0299] [ka]

[0300] (Method for fabricating light-emitting device 6) First, on a glass substrate, silver (Ag), palladium (Pd), and copper (Cu) are used as reflective electrodes. A 100 nm thick alloy film (Ag-Pd-Cu(APC) film) is formed by sputtering. After forming a thick film, indium tin oxide (ITSO) containing silicon oxide is spat as a transparent electrode. Anode 101 was formed by depositing a film with a thickness of 85 nm using the tarring method. The area is 4 mm 2 (2mm x 2mm)

[0301] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface is washed with water, and 2 After firing at 0°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0302] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0303] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. The substrate is fixed to a substrate holder provided inside the vapor deposition apparatus, and vapor deposition is carried out on the anode 101 using resistance heating. N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) is obtained by the bonding method. Benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and AL D-MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20170124) , so that the weight ratio is 1:0.05 (=BBABnf:ALD-MP001Q), 10 A hole injection layer 111 was formed by co-deposition at nm.

[0304] Next, BBABnf is added as the first hole transport layer 112-1 on the hole injection layer 111. After deposition to a size of nm, the above structural formula (vii i) 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole- 3-yl)triphenylamine (abbreviation: PCBBi1BP) was deposited to a thickness of 50 nm. This formed the hole transport layer 112. The second hole transport layer 112-2 is an electron blocking layer. It also functions as such.

[0305] Next, the 8-(1,1'-biphenyl-4-yl)-4- represented by the above structural formula (ix) [3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d] Pyrimidine (abbreviation: 8BP-4mDBtPBfpm) and 9 represented by the above structural formula (x) -(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation) :βNCCP) and [2-methyl-(2-pyridinyl-κ] represented by the above structural formula (xi). N) Benzoflozin[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)flozin [enyl-κC] Iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)] ) and, in a weight ratio of 0.4:0.6:0.1 (=8BP-4mDBtPBfpm:βNCCP Co-deposit a 50nm layer such that :[Ir(ppy)2(mbfpypy)]) to create the light-emitting layer 1 13 was formed.

[0306] Subsequently, on the light-emitting layer 113, 2-{4-[9,10-di(na) represented by the above structural formula (v) is applied. Phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimi Dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviated as Liq) and ZADN are combined in a weight ratio of 0.3:1.0 (=ZADN:Liq). After co-depositing with 17.5nm, the weight ratio becomes 1.0:0.3 (=ZADN:Liq). An electron transport layer 114 was formed by co-depositing a 17.5 nm layer onto the material.

[0307] After forming the electron transport layer 114, the volume ratio of silver (Ag) to magnesium (Mg) is set to 1:0 3. By depositing to a thickness of 15 nm, the cathode 102 is formed and the light-emitting device 6 is created. It was fabricated. The cathode 102 is semi-transparent, possessing both the function of reflecting light and the function of transmitting light. It is a semi-reflective electrode, and the light-emitting device 6 in this embodiment is a top emitter that extracts light from the cathode 102. It is a component of the cushion. Also, on cathode 102 there is 1,3,5-tri(dibenzothiophene). -4-ylbenzene (abbreviation: DBT3P-II) is deposited at 80 nm to improve extraction efficiency. They are raising it.

[0308] The element structure of the light-emitting device 6 is summarized in the table below.

[0309] [Table 7]

[0310] Here, the HOMO level, LUMO level, and electric field strength of the organic compound used in this example [ The following table summarizes the electron mobility at a square root of 600 [V / cm].

[0311] [Table 8]

[0312] This light-emitting device is kept in a glove box under a nitrogen atmosphere, so as not to be exposed to the air. The process involves sealing with a glass substrate (applying a sealing material around the element and performing UV treatment during sealing). After heat treatment at 80°C for 1 hour, initial characteristics and reliability were measured. The measurements were taken at room temperature.

[0313] Figure 37 shows the brightness-current density characteristics of the light-emitting device 6, and Figure 38 shows the current efficiency-brightness characteristics. -Voltage characteristics are shown in Figure 39, current-voltage characteristics in Figure 40, and external quantum efficiency-luminance characteristics in Figure 41. The emission spectrum of the light-emitting device 6 at 1000 cd / m² is shown in Figure 42. 2 Nearby The main characteristics are shown in Table 9.

[0314] [Table 9]

[0315] As shown in Figures 37 to 42 and Table 9, the light-emitting device 6, which is one embodiment of the present invention, has good characteristics. It was found to be a light-emitting device.

[0316] Furthermore, the current density is 50 mA / cm². 2 The graph shows the change in brightness with respect to operating time. As shown in Figure 43, the light-emitting device 6, which is a light-emitting device according to one aspect of the present invention, Even after 250 hours, it maintains a brightness of over 90% of its initial brightness, and the accumulation of operating time... It was found to be a light-emitting device with particularly small brightness degradation and a good lifespan. [Examples]

[0317] In this embodiment, a light-emitting device 7 according to one aspect of the present invention will be described. The structural formulas of the organic compounds are shown below.

[0318] [ka]

[0319] (Method for fabricating light-emitting device 7) First, on a glass substrate, silver (Ag), palladium (Pd), and copper (Cu) are used as reflective electrodes. A 100 nm thick alloy film (Ag-Pd-Cu(APC) film) is formed by sputtering. After forming a thick film, indium tin oxide (ITSO) containing silicon oxide is spat as a transparent electrode. Anode 101 was formed by depositing a film with a thickness of 110 nm using the tarring method. The maximum surface area is 4 mm 2 (2mm x 2mm)

[0320] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface is washed with water, and 2 After firing at 0°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0321] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0322] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. The substrate is fixed to a substrate holder provided inside the vapor deposition apparatus, and vapor deposition is carried out on the anode 101 using resistance heating. N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) is obtained by the bonding method. Benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and AL D-MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20170124) , so that the weight ratio is 1:0.05 (=BBABnf:ALD-MP001Q), 10 A hole injection layer 111 was formed by co-deposition at nm.

[0323] Next, BBABnf is added to the hole injection layer 111 as the first hole transport layer 112-1. After deposition to a size of nm, the above structural formula (xii) is used as the second hole transport layer 112-2. ) represented as N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9 H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2- A hole transport layer 112 is formed by depositing an amine (abbreviated as PCBBiF) to a thickness of 70 nm. The second hole transport layer 112-2 also functions as an electron blocking layer.

[0324] Next, 9-[(3'-dibenzothiophene-4-i) represented by the above structural formula (xiii) [biphenyl-3-yl]naphtho[1',2':4,5]fl[2,3-b]pyrazine (Abbreviation: 9mDBtBPNfpr), PCBBiF, and represented by the above structural formula (xiv) Bis[4,6-dimethyl-2-(7-(2-methylpropyl)-2-quinolinyl-κN )phenyl-κC](2,4-pentanedionato-κ2O,O')iridium(III) (Abbreviation: RS003) and a weight ratio of 0.6:0.4:0.05 (=9mDBtBPNfp A light-emitting layer 113 is formed by co-depositing at 60 nm so that r:PCBBiF:RS003. Ta.

[0325] Subsequently, on the light-emitting layer 113, 2-{4-[9,10-di(na) represented by the above structural formula (v) is applied. Phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimi Dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviated as Liq) and ZADN are combined in a weight ratio of 0.3:1.0 (=ZADN:Liq). After co-depositing with 17.5nm, the weight ratio becomes 1.0:0.3 (=ZADN:Liq). An electron transport layer 114 was formed by co-depositing a 17.5 nm layer onto the material.

[0326] After forming the electron transport layer 114, the volume ratio of silver (Ag) to magnesium (Mg) is set to 1:0 3. By depositing to a thickness of 15 nm, a cathode 102 is formed and the light-emitting device 7 is created. It was fabricated. The cathode 102 is semi-transparent, possessing both the function of reflecting light and the function of transmitting light. It is a semi-reflective electrode, and the light-emitting device 7 in this embodiment is a top emitter that extracts light from the cathode 102. It is a component of the cushion. Also, on cathode 102 there is 1,3,5-tri(dibenzothiophene). -4-ylbenzene (abbreviation: DBT3P-II) is deposited at 80 nm to improve extraction efficiency. They are raising it.

[0327] The element structure of light-emitting device 7 is summarized in the table below.

[0328] [Table 10]

[0329] Here, the HOMO level, LUMO level, and electric field strength of the organic compound used in this example [ The following table summarizes the electron mobility at a square root of 600 [V / cm].

[0330] [Table 11]

[0331] This light-emitting device is kept in a glove box under a nitrogen atmosphere, so as not to be exposed to the air. The process involves sealing with a glass substrate (applying a sealing material around the element and performing UV treatment during sealing). After heat treatment at 80°C for 1 hour, initial characteristics and reliability were measured. The measurements were taken at room temperature.

[0332] Figure 44 shows the brightness-current density characteristics of the light-emitting device 7, and Figure 45 shows the current efficiency-brightness characteristics. -Voltage characteristics are shown in Figure 46, current-voltage characteristics in Figure 47, and external quantum efficiency-luminance characteristics in Figure 48. The emission spectrum of the light-emitting device 7 at 1000 cd / m² is shown in Figure 49. 2 Nearby The main characteristics are shown in Table 12.

[0333] [Table 12]

[0334] As shown in Figures 44 to 49 and Table 12, the light-emitting device 7, which is one embodiment of the present invention, has good characteristics. It was found to be a light-emitting device.

[0335] Furthermore, the current density is 75 mA / cm². 2 A graph showing the change in brightness with respect to operating time (inferior) The emission curve is shown in Figure 50. As shown in Figure 50, the light-emitting device of one aspect of the present invention is light-emitting Device 7 maintains a brightness of over 100% of its initial brightness even after 400 hours. It is a light-emitting device with particularly little decrease in brightness due to the accumulation of operating time, and has a very good lifespan. It was found that the light-emitting device 7 has a characteristic shape in which the degradation curve has a maximum value. Therefore, by exhibiting this kind of degradation behavior, it is possible to create a light-emitting device with a very long lifespan. This is possible. [Examples]

[0336] This embodiment describes a light-emitting device 8 and a light-emitting device 9 according to one aspect of the present invention. The structural formulas of the organic compounds used in light-emitting devices 8 and 9 are shown below.

[0337] [ka]

[0338] (Method for fabricating light-emitting device 8) First, indium tin oxide (ITSO) containing silicon oxide is sputtered onto a glass substrate. A film was deposited using the 2-phase method to form the anode 101. The film thickness was 70 nm, and the electrode area was 2 The dimensions were set to mm x 2 mm.

[0339] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface is washed with water, and 2 After firing at 0°C for 1 hour, UV ozone treatment was performed for 370 seconds.

[0340] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0341] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. The substrate is fixed to a substrate holder provided inside the vapor deposition apparatus, and vapor deposition is carried out on the anode 101 using resistance heating. N,N-bis(4-biphenyl)-6-phenyl represented by the above structural formula (i) is obtained by the bonding method. Benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and AL D-MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20170124) , so that the weight ratio is 1:0.05 (=BBABnf:ALD-MP001Q), 10 A hole injection layer 111 was formed by co-deposition at nm.

[0342] Next, BBABnf is added to the hole injection layer 111 as the first hole transport layer 112-1. After deposition to a size of nm, the second hole transport layer 112-2 is formed using the above structural formula (xv). 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), represented by A hole transport layer 112 was formed by depositing a material to a thickness of 20 nm. Layer 12-2 also functions as an electronic block layer.

[0343] Next, the 9-[3-(4,6-diphenyl-1,3,5] represented by the above structural formula (xvi) -triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazo The term "ru" (abbreviation: mPCCzPTzn-02), PCCP, and the above structural formula (xvii) are expressed. 3',3''',6',6'''-tetraphenyl-9,9',9'',9''' ,9''''-(cyanobenzene-2,3,4,5,6-pentanyl)pentakis(9H -Carbazole (abbreviation: 3Cz2DPhCzBN) and carbazole in a weight ratio of 0.6:0.4:0. 4 A light-emitting layer 113 was formed by co-depositing a 0 nm layer.

[0344] Subsequently, on the light-emitting layer 113, 2-{4-[9,10-di(na) represented by the above structural formula (v) is applied. Phthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzoimi Dazole (abbreviation: ZADN) and 8-hydroxyquinolinate represented by the above structural formula (vi) Lithium (abbreviated as Liq) and 1 are mixed in a weight ratio of 0.4:1 (=ZADN:Liq) After co-deposition at 2.5 nm, 12 layers were deposited so that the weight ratio was 1:0.4 (=ZADN:Liq). A 5nm co-deposited layer was used to form an electron transport layer 114.

[0345] After forming the electron transport layer 114, Liq is deposited to a thickness of 1 nm to form the electron injection layer 1 Forming 15, and then depositing aluminum to a thickness of 200 nm to create a cathode The light-emitting device 8 of this embodiment was fabricated by forming 102.

[0346] (Method for fabricating the light-emitting device 9) Light-emitting device 9 has a BBABnf of 40 nm in the hole transport layer of light-emitting device 8. The light-emitting layer 113 is formed as follows: mPCCzPTzn-02, PCCP, and 3Cz2DP hCzBN and 2,8-di-tert-butyl-5 represented by the above structural formula (xviii), 11-Bis(4-tert-butylphenyl)-6,12-diphenyltetracene (abbreviated) :TBRb) and weight ratio 0.6:0.4:0.5:0.01 (=mPCCzPTzn-0 2:PCCP:3Cz2DPhCzBN:TBRb) is co-deposited at 40nm to form the shape Other than the above, it was fabricated in the same way as light-emitting device 8.

[0347] The element structures of light-emitting devices 8 and 9 are summarized in the table below.

[0348] [Table 13]

[0349] Note that 3Cz2DPhCzBN is a TADF material, and TBRb is a fluorescent material. In other words, the light-emitting device 8 is a light-emitting device that uses TADF material as the light-emitting material, and the light-emitting device Vice 9 uses TBRb as the light-emitting material, and the TBRb is derived from 3Cz2DPhCzBN. It is a light-emitting device that can receive energy.

[0350] Here, the HOMO level, LUMO level, and electric field strength of the organic compound used in this example [ The following table summarizes the electron mobility at a square root of 600 [V / cm].

[0351] [Table 14]

[0352] These light-emitting devices are placed in a glove box under a nitrogen atmosphere, and the light-emitting devices are exposed to the atmosphere. The process of sealing the element with a glass substrate to prevent exposure to sunlight (applying a sealing material around the element and sealing it) After UV treatment and heat treatment at 80°C for 1 hour, the initial characteristics of these light-emitting devices are determined. Reliability was also measured. The measurements were taken at room temperature.

[0353] Figure 51 shows the luminance-current density characteristics of light-emitting devices 8 and 9, and the current efficiency-luminance characteristics. The characteristics are shown in Figure 52, the luminance-voltage characteristics in Figure 53, the current-voltage characteristics in Figure 54, and the external quantum efficiency. -Brightness characteristics are shown in Figure 55, and emission spectrum is shown in Figure 56. Also, the light-emitting device 8 and Optical device 9 at 1000 cd / m² 2 Table 15 shows the main characteristics of the vicinity.

[0354] [Table 15]

[0355] Figures 51 to 56 and Table 15 show a light-emitting device 8 and light-emitting device according to one aspect of the present invention. Both IS9 and IS9 were found to be light-emitting devices with good characteristics.

[0356] Furthermore, the current density is 50 mA / cm². 2 The graph shows the change in brightness with respect to operating time. As shown in Figure 57, a light-emitting device 8 of one aspect of the present invention The light-emitting device 9 increases in brightness after being driven, showing a brightness higher than the initial brightness, and then gradually... It can be seen that it is steadily declining. In other words, it has a maximum point on the deterioration curve. We were able to significantly improve the drive life based on a minimal level of degradation.

[0357] <Reference example 1> In this reference example, the HOMO level, LUMO level, and electron transfer of the organic compounds used in each example are shown. I will now explain how to calculate the degree of motion.

[0358] HOMO and LUMO levels are calculated based on cyclic voltammetry (CV) measurements. It is possible.

[0359] The measuring device used is an electrochemical analyzer (manufactured by BAS Corporation, model number: ALS model). A 600A or 600C was used. The solution used in the CV measurement was dehydrated dimethyl as the solvent. Aldrich Formamide (DMF) (manufactured by Aldrich Co., Ltd., 99.8%, catalog number; 227) Using 05-6), the supporting electrolyte is tetra-n-butylammonium perchlorate (nB u4NClO4) (manufactured by Tokyo Chemical Co., Ltd., catalog number: T0836) 100 mmol / Dissolve to a concentration of L, and then dissolve the sample to be measured to a concentration of 2 mmol / L. It was prepared by dissolving it. Furthermore, a platinum electrode (manufactured by BAS Corporation, PT) was used as the working electrode. E Platinum electrode) is used as an auxiliary electrode, and platinum electrode (manufactured by B.A.S. Co., Ltd., for VC-3 P A counter electrode (5 cm) is used, and an Ag / Ag+ electrode (B.A.A.E.) is used as the reference electrode. A RE7 non-aqueous solvent reference electrode manufactured by S Corporation was used. The measurements were taken at room temperature (20°C). The measurements were performed at 25°C. The scan speed during CV measurement was standardized to 0.1V / sec. The oxidation potential Ea [V] and reduction potential Ec [V] were measured relative to the irradiated electrode. Ea is the oxidation- The intermediate potential of the reduction wave was used, and Ec was set as the intermediate potential of the reduction-oxidation wave. Here, the values ​​used in this embodiment The potential energy of the reference electrode relative to the vacuum level is -4.94 [eV]. Since it is known that the HOMO level [eV] = -4.94 - Ea, the LUMO level [eV The HOMO level and LUMO level can be determined from the equation ] = -4.94 - Ec. It is possible.

[0360] Electron mobility is measured by impedance spectroscopy. It can be measured using the IS method.

[0361] The carrier mobility of EL materials is measured using transient photocurrent (Time-of-flight:T) spectroscopy. OF method and space-charge-limited current Methods such as the SCLC method, which is derived from the IV characteristics of nt (SCLC), have been known for a long time. The TOF method requires a sample with a considerably thicker film thickness compared to actual organic EL elements. The LC method has drawbacks such as not being able to obtain the electric field strength dependence of carrier mobility. Because the thickness of the organic film required for measurement is thin, around several hundred nanometers, even a relatively small amount of EL material can be used. Its key features include the ability to deposit thin films and measure mobility with film thicknesses close to those of actual EL elements. Therefore, the electric field strength dependence of carrier mobility can also be obtained.

[0362] In the IS method, a small sinusoidal voltage signal (V=V0[exp(jωt)]) is applied to the EL element. The current amplitude of the response current signal (I=I0exp[j(ωt+φ)]) and the phase of the input signal From the difference, we can find the impedance of the EL element (Z=V / I). Low frequency voltage from high frequency voltage. By changing it to this extent and applying it to the element, it has various relaxation times that contribute to the impedance. The components can be separated and measured.

[0363] Here, the admittance Y (=1 / Z), which is the reciprocal of impedance, is given by the following equation (1): It can be expressed in terms of conductance G and susceptance B.

[0364]

number

[0365] Furthermore, the single-charge injection model shows that, respectively, Equations (2) and (3) can be calculated. Here, g (equation (4)) is the differential conductor. This is tance. In the formula, C is capacitance, θ is ωt, and the travel angle is... ω represents the angular frequency. t is the travel time. The analysis involves the current equation, Poisson's equation, and current continuity. The equation used ignores the existence of diffusion current and trap levels.

[0366]

number

[0367] The -ΔB method is a method for calculating mobility from the frequency characteristics of capacitance. The ωΔG method is a method for calculating mobility from the frequency characteristics of a device.

[0368] In practice, the first step is to fabricate a measuring element for the material whose electron mobility we want to determine. A measuring element is... This is a device designed so that only electrons flow as carriers. In this specification, capacitance This document explains a method for calculating mobility from the frequency characteristics (-ΔB method). The model of the measuring element used is described below. The diagram is shown in Figure 25.

[0369] The structure of the measuring element fabricated for this measurement is as shown in Figure 25, consisting of an anode 201 and a cathode 2 Between 02 there are a first layer 210, a second layer 211, and a third layer 212. Electron mobility The desired material can be used as the material for the second layer 211. In this case, ZADN and Liq 1 This will be explained using an example of measuring the electron mobility of a co-evaporated film with a weight ratio of :1. Typical configuration examples are summarized in the table below.

[0370] [Table 16]

[0371] Current density of a measuring element fabricated with a co-evaporated film of ZADN and Liq as the second layer 211. The pressure characteristics are shown in Figure 26.

[0372] Impedance measurement is performed by applying a DC voltage in the range of 5.0V to 9.0V while simultaneously measuring the AC voltage. Measurements were taken under the conditions of 70mV and a frequency of 1Hz to 3MHz. The impedance obtained here Capacitance is calculated from admittance (equation (1) above), which is the reciprocal of dance. Figure 27 shows the frequency characteristics of the calculated capacitance C at an applied voltage of 7.0V.

[0373] The frequency characteristics of capacitance C are determined by the spatial charge of carriers injected by a small voltage signal. This is obtained when the load cannot fully follow the minute AC voltage, resulting in a phase difference in the current. Here, the travel time of the carriers in the membrane is the time T it takes for the injected carriers to reach the counter electrode. It is defined and expressed by the following equation (5).

[0374]

number

[0375] The negative susceptance change (-ΔB) is the value obtained by multiplying the capacitance change -ΔC by the angular frequency ω (-ωΔ). This corresponds to C). Its lowest frequency peak frequency is f'. max (=ω max ( / 2π) and run From equation (3), the following relationship (6) can be derived between row time T and row time.

[0376]

number

[0377] Figure 2 shows the frequency characteristics of -ΔB calculated from the above measurements (i.e., when the DC voltage is 7.0V). As shown in 8, the lowest frequency peak frequency f' can be determined from Figure 28. max This is indicated by the arrow in the diagram. did.

[0378] f' obtained from the above measurements and analysis max Therefore, the travel time T can be determined (using the above formula ( 6) See also), from equation (5) above, we can determine the electron mobility at a voltage of 7.0V in this case. This can be done. By performing similar measurements in the DC voltage range of 5.0V to 9.0V, each voltage can be determined. Since electron mobility can be calculated at (electric field strength), the dependence of mobility on electric field strength can also be measured.

[0379] Using the calculation methods described above, the final electron mobility of each organic compound depends on the electric field strength. Figure 29 shows the values, and the square root of the electric field strength [V / cm] read from the figure is 600 [V / cm]. 1 / 2 Table 17 shows the electron mobility values ​​for each of these conditions.

[0380] [Table 17]

[0381] As described above, it is possible to calculate electron mobility. For detailed measurement methods, please refer to the following. Takayuki Okachi et al. "Japanese Journal of Applied Physics” Vol. 47, No. 12, 2008, Please refer to pp. 8965-8972.

[0382] <Reference example 2> The 9mDBtBPNfpr and 8BP-4mDBtPBfpm used in the examples are not publicly disclosed. Since these are substances, we will explain their respective synthesis methods.

[0383] ≪Method for synthesizing 9mDBtBPNfpr≫ In Example 4, the structural formula (xiii) is 9-[(3'-dibenzothiophene] -4-yl)biphenyl-3-yl]naphtho[1',2':4,5]fl[2,3-b] This document describes the synthesis method for pyrazine (abbreviation: 9mDBtBPNfpr). The structure of BtBPNfpr is shown below.

[0384] [ka]

[0385] <Step 1: 6-Chloro-3-(2-methoxynaphthalene-1-yl)pyrazine-2- Amine synthesis > First, 4.37g of 3-bromo-6-chloropyrazine-2-amine and 2-methoxynaphthalene 4.23g of 1-boronic acid, 4.14g of potassium fluoride, 75g of anhydrous tetrahydrofuran The mL was placed in a three-necked flask fitted with a reflux condenser, and the inside was purged with nitrogen. The inside of the flask was then subjected to reduced pressure. After degassing by stirring, Tris(dibenzylideneacetone)dipalladium(0)( Abbreviation: Pd2(dba)3) 0.57g, tri-tert-butylphosphine (Abbreviation: P (tBu)3)4.5 mL was added and the mixture was stirred at 80°C for 54 hours to allow the reaction to proceed.

[0386] After a predetermined time had elapsed, the resulting mixture was filtered by suction, and the filtrate was concentrated. Subsequently, toluene:vinegar was added. Purification was performed by silica gel column chromatography using ethyl acid = 9:1 as the developing solvent. The desired pyrazine derivative was obtained (yellowish-white powder, yield 2.19 g, yield 36%). Step 1 The synthesis scheme is shown below.

[0387] [ka]

[0388] <Step 2: 9-Chloronaphtho[1',2':4,5]Flo[2,3-b]pyrazine Synthesis> Next, the 6-chloro-3-(2-methoxynaphthalene-1-yl) py obtained in step 1 above. 2.18 g of radin-2-amine, 63 mL of anhydrous tetrahydrofuran, and 84 mL of glacial acetic acid are mixed together. The solution was placed in a mouthed flask and the inside was purged with nitrogen. After the flask was cooled to -10°C, nitrite te 2.8 mL of rt-butyl was added dropwise, and the mixture was stirred at -10°C for 30 minutes and then at 0°C for 3 hours. After the procedure, 250 mL of water was added to the resulting suspension and filtered by suction to obtain the desired pyrazol. A derivative was obtained (yellowish-white powder, yield 1.48 g, yield 77%). Step 2 synthesis ski The "Mu" is shown below.

[0389] [ka]

[0390] <Step 3: 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl] Naphtho[1',2':4,5]flof[2,3-b]pyrazine (abbreviation: 9mDBtBPNf) pr) synthesis > Furthermore, the 9-chloronaphtho[1',2':4,5]floxacin[2,3- obtained in step 2 above 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 tanol was placed in a three-necked flask, and the inside was purged with nitrogen. The inside of the flask was stirred under reduced pressure. After degassing by mixing, bis(triphenylphosphine)palladium(II) dichloride Add 0.84g of Pd(PPh3)2Cl2 and stir at 80°C for 18 hours. They responded.

[0391] After a predetermined time had elapsed, the obtained suspension was filtered by suction and washed with water and ethanol. The body is dissolved in toluene and passed through a filtration aid consisting of layers of Celite, alumina, and Celite. After filtering, the target product was obtained by recrystallization in a mixed solvent of toluene and hexane. Pale yellow solid, yield 2.66g, 82% yield.

[0392] The resulting pale yellow solid (2.64 g) was purified by sublimation using the train sublimation method. The purification conditions were: pressure 2.6 Pa, argon gas flow rate 15 mL / min, and 3 The solid was heated at 15°C. After sublimation purification, the target product was obtained as a pale yellow solid in a yield of 2.34 g and 89%. The result was obtained in percentages. The synthesis scheme for Step 3 is shown below.

[0393] [ka]

[0394] Furthermore, nuclear magnetic resonance spectroscopy of the pale yellow solid obtained in step 3 above ( 1 (H-NMR) The analysis results are shown below. From these results, it was found that 9mDBtBPNfpr was obtained. .

[0395] 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).

[0396] ≪Method for synthesizing 8BP-4mDBtPBfpm≫ In Example 3, the structural formula (ix) is 8-(1,1'-biphenyl-4-yl). )-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3, This document explains the synthesis method of [2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm). The structure of 8BP-4mDBtPBfpm is shown below.

[0397] [ka]

[0398] <8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl) Synthesis of phenyl-[1]benzofl[3,2-d]pyrimidine 8-Chloro-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzo [3,2-d]pyrimidine 1.37g, 4-biphenylboronic acid 0.657g, phosphate 1.91g of tripotassium, 30mL of diglycerin, and 0.662g of t-butanol in a three-necked flask. The contents were placed in a container, degassed by stirring under reduced pressure in the flask, and then purged with nitrogen.

[0399] This mixture is heated to 60°C, and 23.3 mg of palladium(II) acetate and di(1-adamantine) are added. 66.4 mg of tyl-n-butylphosphine was added and stirred at 120°C for 27 hours. Water was added to the reaction mixture and filtered by suction. The resulting filtrate was washed with water, ethanol, and toluene. This material was dissolved in heated toluene, and then filled with Celite, alumina, and Celite in that order. The solution was passed through an auxiliary agent. The resulting solution was concentrated, dried, and recrystallized with toluene. The target white solid was obtained in a yield of 1.28 g and 74%.

[0400] 1.26 g of this white solid was purified by sublimation using the train sublimation method. Sublimation purification The conditions were: pressure 2.56 Pa, argon gas flow rate 10 mL / min, and 310 The solid was heated at °C. After sublimation purification, 1.01 g of the target product, a pale yellow solid, was obtained with a recovery rate of 80%. The synthesis scheme is shown below.

[0401] [ka]

[0402] Furthermore, nuclear magnetic resonance spectroscopy of the pale yellow solid obtained from the above reaction ( 1 Analysis results by H-NMR The results are shown below. From these results, it can be seen that 8BP-4mDBtPBfpm was obtained. Ta.

[0403] 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). [Explanation of Symbols]

[0404] 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 Emitting layer 113-1 Emitting region 114 Electron transport layer 114-1 First electron transport layer 114-2 Second electron transport layer 115 Electron injection layer 116 Charge generation layer 117 P type layer 118 Electron relay layer 119 Electron injection buffer layer 120 Non-luminescent recombination region 201 Anode 202 Cathode 210 First layer 211 Second Layer 212 The third layer 400 circuit boards 401 Anode 403 EL layer 404 Cathode 405 sealant 406 Sealant 407 Sealing substrate 412 pads 420 IC chips 501 Anode 502 Cathode 511 First light-emitting unit 512 Second light-emitting unit 513 Charge generation layer 601 Drive circuit section (source line drive circuit) 602 pixel section 603 Drive circuit section (gate wire drive circuit) 604 Sealing substrate 605 Sealant 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 element substrate 611 Switching FET 612 Current-Controlled FET 613 Anode 614 Insulators 616 EL layer 617 Cathode 618 Light-emitting devices 951 circuit board 952 Electrode 953 Insulating layer 954 Partition layer 955 EL layer 956 Electrode 1001 circuit board 1002 Underlying insulating film 1003 Gate Insulator 10:06 Guard Station 1007 🙏 1008 Gate 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 Sealant 1033 Transparent base material 1034R Red colored 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 Peripheral area 2001 cabinet 2002 light source 2100 Robots 2110 Arithmetic equipment 2101 Illuminance Sensor 2102 Microphone 2103 Top camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 3001 Lighting device 5000 cabinets 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 Buttons 5150 Mobile Information Terminal 5151 enclosure 5152 Display area 5153 Bent section 5120 Garbage 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 enclosure 7103 Display section 7105 Stand 7107 Display section 7109 Operation Keys 7110 Remote Control Unit 7201 Main Unit 7202 enclosure 7203 Display section 7204 Keyboard 7205 External connection port 7206 Pointing device 7210 Second display unit 7401 enclosure 7402 Display section 7403 Operation Buttons 7404 External connection port 7405 Speaker 7406 Microphone 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 enclosure

Claims

1. Anode and, Cathode and, A light-emitting device having an EL layer located between the anode and the cathode, The EL layer has an emissive layer and an electron transport layer, The electron transport layer comprises a first substance and a second substance. The first substance is an alkali metal or alkaline earth metal in its elemental form, an organic complex, or a compound thereof. The second substance is an organic compound that has electron transport properties, The electron transport layer has regions in its thickness direction where either or both of the amounts of the first substance and the second substance are different. In the electron transport layer, there is a region on the anode side where the amount of the first substance is greater than the region where the amount of the first substance is less. The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device, has a maximum value. A light-emitting device having a portion of the degradation curve that exceeds 100%.

2. Anode and, Cathode and, A light-emitting device having an EL layer located between the anode and the cathode, The EL layer has an emissive layer and an electron transport layer, The electron transport layer comprises a first substance and a second substance. The first substance is an alkali metal or alkaline earth metal in its elemental form, an organic complex, or a compound thereof. The second substance is an organic compound that has electron transport properties, The electron transport layer has regions in its thickness direction where either or both of the amounts of the first substance and the second substance are different. In the electron transport layer, there is a region on the anode side where the amount of the second substance is less than the region where the amount of the second substance is greater. The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device, has a maximum value. A light-emitting device having a portion of the degradation curve that exceeds 100%.

3. Anode and, Cathode and, A light-emitting device having an EL layer located between the anode and the cathode, The EL layer has, in order from the anode side, a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer. The first layer comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance. The first organic compound is an organic compound that exhibits electron-accepting ability to the second organic compound, The fifth organic compound is a luminescence center material, The first substance is an alkali metal or alkaline earth metal in its elemental form, an organic complex, or a compound thereof. The HOMO level of the second organic compound is between -5.7 eV and -5.4 eV. The seventh organic compound has an electron mobility of 1 × 10⁻¹⁰ at an electric field strength [V / cm] square root of 600. －７ cm ２ / Vs or more 5×10 －５ cm ２ It is a substance with a Vs of less than or equal to / Vs. The fourth layer has regions in its thickness direction where either or both of the amounts of the seventh organic compound and the first substance are different. In the fourth layer, there is a region on the anode side where the amount of the seventh organic compound is less than the region where the amount of the seventh organic compound is greater. The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device, has a maximum value. A light-emitting device having a portion of the degradation curve that exceeds 100%.

4. Anode and, Cathode and, A light-emitting device having an EL layer located between the anode and the cathode, The EL layer has, in order from the anode side, a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer. The first layer is in contact with the anode, The fourth layer is in contact with the light-emitting layer, The first layer comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance. The first organic compound is an organic compound that exhibits electron-accepting ability to the second organic compound, The fifth organic compound is a luminescence center material, The first substance is an alkali metal or alkaline earth metal in its elemental form, an organic complex, or a compound thereof. The HOMO level of the second organic compound is between -5.7 eV and -5.4 eV. The seventh organic compound has an electron mobility of 1 × 10⁻¹⁰ at an electric field strength [V / cm] square root of 600. －７ cm ２ / Vs or more 5×10 －５ cm ２ It is a substance with a Vs of less than or equal to / Vs. The HOMO level of the seventh organic compound is -6.0 eV or higher, The fourth layer has regions in its thickness direction where either or both of the amounts of the seventh organic compound and the first substance are different. In the fourth layer, there is a region on the anode side where the amount of the seventh organic compound is less than the region where the amount of the seventh organic compound is greater. The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device, has a maximum value. A light-emitting device having a portion of the degradation curve that exceeds 100%.

5. Anode and, Cathode and, A light-emitting device having an EL layer located between the anode and the cathode, The EL layer has, in order from the anode side, a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer. The first layer is in contact with the anode, The fourth layer is in contact with the light-emitting layer, The first layer comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance. The first organic compound is an organic compound that exhibits electron-accepting ability to the second organic compound, The fifth organic compound is a luminescence center material, The first substance is an alkali metal or alkaline earth metal in its elemental form, an organic complex, or a compound thereof. The HOMO level of the second organic compound is between -5.7 eV and -5.4 eV. The difference in HOMO levels between the third organic compound and the second organic compound is 0.2 eV or less. The HOMO level of the third organic compound is the same as or deeper than the HOMO level of the second organic compound. The seventh organic compound has 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 intensity [V / cm] is 600, The HOMO level of the seventh organic compound is -6.0 eV or higher, The fourth layer has regions in its thickness direction where either or both of the amounts of the seventh organic compound and the first substance are different. In the fourth layer, there is a region on the anode side where the amount of the seventh organic compound is less than the region where the amount of the seventh organic compound is greater. The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device, has a maximum value. A light-emitting device having a portion of the degradation curve that exceeds 100%.

6. Anode and, Cathode and, A light-emitting device having an EL layer located between the anode and the cathode, The EL layer has, in order from the anode side, a first layer, a second layer, a third layer, a light-emitting layer, and a fourth layer. The first layer is in contact with the anode, The fourth layer is in contact with the light-emitting layer, The first layer comprises a first organic compound and a second organic compound. The second layer has a third organic compound, The third layer has a fourth organic compound, The light-emitting layer has a fifth organic compound and a sixth organic compound, The fourth layer comprises a seventh organic compound and a first substance. The first organic compound is an organic compound that exhibits electron-accepting ability to the second organic compound, The second organic compound has a first hole-transporting skeleton, The third organic compound has a second hole-transporting skeleton, The fourth organic compound has a third hole-transporting skeleton, The fifth organic compound is a luminescence center material, The first substance is an alkali metal or alkaline earth metal in its elemental form, an organic complex, or a compound thereof. The HOMO level of the second organic compound is between -5.7 eV and -5.4 eV. The first hole-transporting skeleton, the second hole-transporting skeleton, and the third hole-transporting skeleton are each independently one of the carbazole skeleton, dibenzofuran skeleton, dibenzothiophene skeleton, and anthracene skeleton. The seventh organic compound has an electron mobility of 1 × 10⁻¹⁰ at an electric field strength [V / cm] square root of 600. －７ cm ２ / Vs or more 5×10 －５ cm ２ It is a substance with a Vs of less than or equal to / Vs. The HOMO level of the seventh organic compound is -6.0 eV or higher, The fourth layer has regions in its thickness direction where either or both of the amounts of the seventh organic compound and the first substance are different. In the fourth layer, there is a region on the anode side where the amount of the seventh organic compound is less than the region where the amount of the seventh organic compound is greater. The degradation curve, which is represented by the change in brightness of the light emitted when a constant current is passed through the light-emitting device, has a maximum value. A light-emitting device having a portion of the degradation curve that exceeds 100%.

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