Light-emitting devices

Abstract

To provide an electronic device having high light extraction efficiency or light trapping effect.SOLUTION: An electronic device has a first layer and a second layer between a first electrode and a second electrode, and the first layer between the first electrode and the second layer, the first layer has a first organic compound and a first substance, the refractive index of the thin film of the first organic compound is 1 or more and 1.75 or less, the first substance has electron-accepting properties, and the second layer has a function of emitting or absorbing light.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a novel electronic device, or an organic compound with a low refractive index. Regarding the electronic devices used, or light-emitting devices, electronic devices, and having such electronic devices. Regarding lighting equipment.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. One aspect of the present invention is a product, a method , or relating to a manufacturing method. Or, the present invention relates to a process, machine, or manufacture. , or relating to a composition of matter. In particular, one aspect of the present invention is Electronic devices, semiconductor devices, light-emitting devices, display devices, lighting devices, light-emitting elements, and their manufacturing Regarding the method. [Background technology]

[0003] Electroluminescence (EL) using organic compounds Electronic devices such as light-emitting elements (organic EL elements) and organic solar cells that utilize cence Practical applications are progressing. The basic structure of these electronic devices is an organic compound between a pair of electrodes. It consists of a semiconductor layer containing [a specific component] sandwiched in between.

[0004] Such electronic devices are lightweight, flexible, and highly aesthetically pleasing. They are also capable of being coated. Because of its various advantages, research and development are actively underway. In particular, the light-emitting element is self-luminous. Therefore, when used as pixels in a display, it offers high visibility and eliminates the need for a backlight. It has several advantages, and is therefore suitable as a flat panel display element.

[0005] Such electronic devices mainly have an organic semiconductor layer formed by thinning organic compounds. Since organic compounds and layer structures have a significant impact on organic semiconductor devices, organic compounds and The choice of layer structure is important. Furthermore, like organic solar cells and organic EL elements, the light-emitting properties Alternatively, in electronic devices that absorb light, structures with high light extraction efficiency and light confinement effect are often used. It is essential.

[0006] Various methods have been proposed to improve the light extraction efficiency of organic EL elements. For example, Patent Document 1 By creating uneven surfaces on the electrodes and parts of the EL layer, the light extraction efficiency is improved. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2013-033706 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In light-emitting elements such as organic EL elements, a method to improve light extraction efficiency is to use a basic There is a method for adjusting the refractive index between the plate and the electrode and / or between the electrode and the EL layer. However, introducing a layer to adjust the refractive index into an organic EL element presents a problem of process complexity. Therefore, there is a need to develop layers and layer structures that have the functionality of an EL layer while also being able to control the refractive index. Furthermore, in organic solar cells, there is a demand for the development of layers and layer structures with high light confinement effects. It is being criticized.

[0009] In view of the above-mentioned problems, one aspect of the present invention provides an electronic device with high light extraction efficiency. The problem is to provide an electronic device that includes a layer with a low refractive index. Alternatively, in one aspect of the present invention, an electronic device including a layer with a low refractive index is provided. The objective is to provide an electronic device with a low drive voltage. Alternatively, in one aspect of the present invention, to provide an electronic device with a low drive voltage. The objective is to achieve the following. Alternatively, in one aspect of the present invention, an electronic device with reduced power consumption is provided. The objective is to provide a reliable electronic device. Alternatively, in one aspect of the present invention, a reliable electronic device The objective is to provide a device with high luminescence efficiency. In one aspect of the present invention, an electronic device with high luminescence efficiency is provided. The objective is to provide a novel electronic device. Alternatively, in one aspect of the present invention, a novel electronic device is provided. The objective is to provide an electronic device with a high light confinement effect. Alternatively, in one aspect of the present invention, an electronic device with a high light confinement effect is provided. The objective is to provide a chair. Alternatively, in one aspect of the present invention, a novel semiconductor device is provided. The objective is to provide it.

[0010] The description of the above problems does not preclude the existence of other problems. Furthermore, one aspect of the present invention is not necessarily However, it is not necessary to solve all of these issues. Other issues can be addressed by describing them in the specifications, etc. This is self-evident, and it is possible to extract other issues from the description in the specification, etc. . [Means for solving the problem]

[0011] One aspect of the present invention has a first layer and a second layer between a first electrode and a second electrode, Between the electrode and the second layer, there is a first layer, and the first layer contains a first organic compound and a first substance. The first organic compound has a refractive index of 1 or more and 1.75 or less, and the first substance is electron It is an electronic device in which the first layer is receptive and the second layer has the function of emitting or absorbing light. .

[0012] Another aspect of the present invention has a first layer between the first electrode and the second electrode, and the first The layer has a first organic compound and a first substance, the first organic compound having a first skeleton and electron-donating It has a sex skeleton, and the first skeleton is either a tetraarylmethane skeleton or a tetraarylsilane skeleton. It is an electronic device.

[0013] In the above configuration, the refractive index of the first layer is preferably 1 or more and 1.75 or less. This can improve the light extraction efficiency and light confinement effect of electronic devices.

[0014] Furthermore, in the above configuration, the tetraarylmethane skeleton and the tetraarylsilane skeleton are Each of these aryl groups is independently a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. This is preferable. Furthermore, it is more preferable that the aryl group is a substituted or unsubstituted phenyl group. By using this composition, it is possible to obtain organic compounds with a low refractive index and good carrier transport properties. Furthermore, the aryl groups or phenyl groups may bond to each other to form a ring.

[0015] Furthermore, in the above configuration, the electron-donating skeleton consists of a pyrrole skeleton, an aromatic amine skeleton, and an acridi It is preferable to include either an azepine skeleton or an azepine skeleton. With this configuration, The drive voltage of the child device can be reduced.

[0016] Furthermore, in the above configuration, the glass transition temperature (Tg) of the first organic compound is 100°C or higher. This is preferable. By adopting this configuration, an electronic device with excellent heat resistance can be obtained.

[0017] Furthermore, in the above configuration, it is preferable that the refractive index of the first layer is lower than that of the second layer. This configuration improves the light extraction efficiency and light confinement effect of electronic devices. can.

[0018] Another aspect of the present invention involves a first layer, a second layer and between the first electrode and the second electrode. It has a third layer, and between the first electrode and the second layer, it has a first layer, and between the first layer and the third layer It has a second layer in between, and the first layer has a first organic compound and a first substance, and the first organic compound The refractive index of the thin film of the material is between 1 and 1.75, the first material has electron-accepting properties, and the third The layers have the function of emitting or absorbing light, and the refractive index of the first layer is lower than that of the second layer. Furthermore, it is an electronic device in which the refractive index of the first layer is lower than that of the third layer.

[0019] Furthermore, in the above configuration, it is preferable that the first organic compound has electron-donating properties. This makes it possible to obtain electronic devices with good carrier transportability.

[0020] Furthermore, in the above configuration, it is preferable that the first layer and the second layer are in contact, and the second layer and the third layer It is even more preferable if they are in contact. This configuration makes it possible to suppress refractive index steps between each layer. This can improve the light extraction efficiency and light confinement effect of electronic devices.

[0021] Furthermore, in the above configuration, it is preferable that the refractive index of the first layer is lower than the refractive index of the first electrode. This configuration improves the light extraction efficiency and light confinement effect of electronic devices. can.

[0022] Furthermore, in the above configuration, in the first layer, the volume ratio of the first substance is the first organic compound It is preferable that the ratio is between 0.01 and 0.3. By using this configuration, electronic devices This can improve the light extraction efficiency and light confinement effect.

[0023] Furthermore, in the above configuration, the first substance is titanium oxide, vanadium oxide, tantalum oxide Materials, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, chromium oxide It is preferable that it contains one of the following: a humic oxide, zirconium oxide, hafnium oxide, or silver oxide. This configuration makes it possible to obtain an electronic device with good carrier transportability.

[0024] Furthermore, in the above configuration, the first substance is 7,7,8,8-tetracyanoquinodimethane (omitted) Name: TCNQ), 7,7,8,8-tetracyano-2,3,5,6-tetrafluoro-k Nodimethane (abbreviation: F4TCNQ) and 1,3,4,5,7,8-hexafluorotetra It is preferable that it be one of the following cyano-naphthoquinodimethanes (abbreviation: F6TCNNQ). By adopting this configuration, an electronic device with good carrier transportability can be obtained.

[0025] Furthermore, in the above configuration, it is preferable that the electronic device is an organic EL element or a solar cell. .

[0026] Furthermore, another aspect of the present invention relates to the above-described light-emitting element and a housing or touch sensor. It is an electronic device having at least one of the above configurations. Another aspect of the present invention is an electronic device having each of the above configurations A lighting device having a device and at least one of a housing, connection terminals, or protective cover. Furthermore, one aspect of the present invention is not only a light-emitting device having an electronic device, but also a light-emitting device having Electronic devices that do so are also included in the scope. Therefore, the term "light-emitting device" in this specification refers to an image display device. This refers to a chair or a light source (including lighting devices). It also refers to a connector on the light-emitting element, such as an FP (Fixed Point). C (Flexible Printed Circuit), TCP (Tape Car) A display module with a rier package attached, print distribution to the TCP destination. A display module or electronic device equipped with a wire plate, or a COG (Chip On Glue) A display module in which an IC (integrated circuit) is directly mounted using the ass method is also one embodiment of the present invention. That is the case. [Effects of the Invention]

[0027] According to one aspect of the present invention, an electronic device with high light extraction efficiency can be provided. According to one aspect of the present invention, an electronic device including a layer with a low refractive index can be provided. Alternatively, according to one aspect of the present invention, an electronic device with a low drive voltage can be provided. To provide an electronic device with reduced power consumption according to one aspect of the present invention. This is possible. Alternatively, according to one aspect of the present invention, a highly reliable electronic device can be provided. This is possible. Alternatively, according to one aspect of the present invention, an electronic device with high luminous efficiency can be provided. It is possible to provide a novel electronic device according to one aspect of the present invention. This is possible. Alternatively, one aspect of the present invention provides an electronic device with a high light confinement effect. It is possible to provide a novel semiconductor device according to one aspect of the present invention. can.

[0028] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention is: It is not necessarily required to have all of these effects. Other effects are described in the specification. This is obvious from the descriptions in the specifications, drawings, and claims, and the descriptions in the specifications, drawings, and claims Therefore, it is possible to extract effects other than those mentioned above. [Brief explanation of the drawing]

[0029] [Figure 1] A schematic cross-sectional view of an electronic device according to one embodiment of the present invention. [Figure 2] A schematic cross-sectional view and a diagram illustrating the optical path length of a light-emitting element according to one embodiment of the present invention. [Figure 3] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention, and a diagram illustrating the correlation of energy levels related to the light-emitting layer. [Figure 4] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention, and a diagram illustrating the correlation of energy levels related to the light-emitting layer. [Figure 5] A conceptual diagram of an active matrix type light-emitting device according to one aspect of the present invention. [Figure 6] A conceptual diagram of an active matrix type light-emitting device according to one aspect of the present invention. [Figure 7] A conceptual diagram of an active matrix type light-emitting device according to one aspect of the present invention. [Figure 8] A schematic diagram of an electronic device according to one aspect of the present invention. [Figure 9] A schematic diagram of an electronic device according to one aspect of the present invention. [Figure 10] A diagram showing a lighting device according to one aspect of the present invention. [Figure 11] A diagram showing a lighting device according to one aspect of the present invention. [Figure 12] A diagram illustrating the refractive index in the example. [Figure 13] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 14] A diagram illustrating the current density-voltage characteristics of a light-emitting element according to an embodiment. [Figure 15] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 16] A diagram illustrating the emission spectrum in an example. [Figure 17] A diagram illustrating the external quantum efficiency-chromaticity x characteristics of a light-emitting element according to an embodiment. [Figure 18] A diagram illustrating the relationship between external quantum efficiency and the volume ratio of MoO3 in the example. [Figure 19]A diagram illustrating the refractive index in the example. [Figure 20] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 21] A diagram illustrating the current density-voltage characteristics of a light-emitting element according to an embodiment. [Figure 22] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 23] A diagram illustrating the emission spectrum in an example. [Figure 24] A diagram illustrating the external quantum efficiency-chromaticity x characteristics of a light-emitting element according to an embodiment. [Figure 25] A diagram illustrating the refractive index in the example. [Figure 26] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 27] A diagram illustrating the current density-voltage characteristics of a light-emitting element according to an embodiment. [Figure 28] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 29] A diagram illustrating the emission spectrum in an example. [Figure 30] A diagram illustrating the reliability test results for the example. [Figure 31] A diagram illustrating the external quantum efficiency-chromaticity x characteristics of a light-emitting element according to an embodiment. [Figure 32] A diagram illustrating the external quantum efficiency-chromaticity y characteristics of a light-emitting element according to an embodiment. [Modes for carrying out the invention]

[0030] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is as follows The description is not limited to the present invention, and the form and details may not depart from the spirit and scope of the present invention. It is possible to change this in various ways. Therefore, the present invention can be described in the embodiments shown below. It is not interpreted as being limited to volume.

[0031] For the sake of ease of understanding, the position, size, and scope of each component shown in the drawings, etc., are as follows: The actual location, size, and range may not be represented. Therefore, the disclosed invention may not reflect the actual location, size, or range. It is not necessarily limited to the location, size, or scope disclosed in drawings, etc.

[0032] Furthermore, in this specification, the ordinal numbers used as "1st," "2nd," etc., are used for convenience. The order of processes or stacking may not be indicated. For example, "the first" may be written as "the second" or This can be replaced with "third," etc., as appropriate in the explanation. The ordinal numbers used to specify one aspect of this invention may not be the same. be.

[0033] Furthermore, in this specification and other documents, when describing the structure of the invention using drawings, the same thing is used The symbols used may be consistent across different drawings.

[0034] Furthermore, in this specification, the terms "membrane" and "layer" are interchangeable. It is possible to change the term. For example, the term "conductive layer" can be changed to the term "conductive film." It may be possible to change it. Or, for example, change the term "insulating film" to "insulating layer". In some cases, it may be possible to change the terminology to this.

[0035] Furthermore, the refractive index n includes n Ordinary, which is the refractive index of ordinary light, and n Ordinary, which is the refractive index of extraordinary light. n Extraordinary and n average are the average of the two. In this specification, if the term "refractive index" is used without anisotropy analysis, then n If anisotropic analysis is performed, you can substitute "average" with "n Ordinary". No. Also, anisotropy refers to the difference between n Ordinary and n Extraordinary. It is expressed as the difference. Note that the value of n Ordinary is doubled, and n Extraordinary is also used. The n average is the sum of the nary values ​​divided by 3.

[0036] In this specification, room temperature refers to a temperature in the range of 0°C to 40°C.

[0037] (Embodiment 1) In this embodiment, an electronic device according to one aspect of the present invention will be described below with reference to Figure 1. ru.

[0038] <Example 1 of Electronic Device Configuration> The electronic device 50 has a pair of electrodes (electrode 11 and It has an electrode 12) and an organic semiconductor layer 20. The organic semiconductor layer 20 has at least a carrier transport It has a transmission layer 30 and a functional layer 40. The organic semiconductor layer 20 may have multiple functional layers. stomach.

[0039] Preferably, the functional layer 40 of the electronic device 50 has the function of absorbing or emitting light. Electrode 1 When light generated in the functional layer 40 is extracted from side 1, the light that has passed through the substrate 10 is connected to the electrode 11 and It will pass through the carrier transport layer 30. Alternatively, from the electrode 11 side, it will pass through the organic semiconductor layer 20 When light entering the substrate is absorbed by the functional layer 40, the light that has passed through the substrate 10 is absorbed by the electrode 11 and the capacitor. It will pass through the rear transport layer 30. Until the light generated in the functional layer 40 is efficiently extracted. Alternatively, in order for light to be efficiently absorbed by the functional layer 40, the electrode 11 and the carrier transport layer 30 It is preferable that less light is attenuated in that case.

[0040] However, in the electronic device 50, the attenuation mode called the evanescent mode It is known that light is attenuated in the organic semiconductor layer 20. For example, in the functional layer 40 If light is generated, the light generated in the functional layer 40 passes through or is reflected by the electrode 11, Attenuation occurs through the vanessen mode.

[0041] Here, it is known that if a layer with a lower refractive index exists in the layer through which light passes, the amount of attenuated light decreases. In Figure 1, by using a layer with a low refractive index in the carrier transport layer 30, the amount of radiation is reduced. It can suppress the fading of light.

[0042] However, in many cases, the carrier transport layer 30 has carrier transport properties or carrier injection characteristics. Therefore, the carrier transport layer 30 is a carrier-receiving or carrier-donating material. The substance used is a carrier-receiving or carrier-donating material, as many of these materials have a high refractive index. Therefore, the refractive index of the carrier transport layer 30 becomes high. In other words, it has carrier transport properties. Furthermore, it was difficult to obtain a layer with a low refractive index. Also, carrier acceptance or carrier supply If the donating substance is an organic compound, the structure of the organic compound may contain a cyclohexane skeleton. It is known that the refractive index decreases when saturated cyclic compounds are present, but this presents problems with heat resistance. .

[0043] Here, the present inventors have found that by mixing an organic compound with a low refractive index into the carrier transport layer 30, Even when using a material with high electron-accepting properties and high refractive index, it is possible to achieve refraction while maintaining carrier transport properties. We found that we could create layers with a low concentration. Furthermore, we found that we could create a tetraarylmethane skeleton or tetra Either one of the laarylsilane skeletons and an organic compound having an electron-donating group as a carrier By mixing it with the transport layer 30, even if a material with high refractive index and electron-accepting properties is used, We discovered that it is possible to fabricate a layer with low refractive index while possessing carrier transport properties. In addition, the organic compound We discovered that the composite material also has excellent heat resistance.

[0044] The refractive index of the above-mentioned organic compound with a low refractive index is preferably 1 or more and 1.75 or less. Or more preferably 1 or more and 1.73 or less, and more preferably 1.70 or less. This allows for the creation of a good electronic device with reduced light attenuation.

[0045] Either the tetraarylmethane skeleton or the tetraarylsilane skeleton mentioned above, and electricity The refractive index of the organic compound having a child-donating group is preferably 1 or more and 1.75 or less, and more preferably The value is 1 or more and 1.73 or less, more preferably 1.70 or less. This allows for the creation of electronic devices with reduced light attenuation and improved light extraction efficiency.

[0046] <Example of Electronic Device Configuration 2> In the following section, an example of an electronic device according to one aspect of the present invention, a light-emitting element, will be described using Figure 2. The following explains further.

[0047] Figure 2(A) is a schematic cross-sectional view of a light-emitting element 150 according to one embodiment of the present invention.

[0048] The light-emitting element 150 has substrates 200 and 210, and between substrates 200 and 210 It has a pair of electrodes (electrode 101 and electrode 102), and an EL is provided between the pair of electrodes. It has a layer 100. The EL layer 100 has at least a light-emitting layer 130.

[0049] Furthermore, the EL layer 100 shown in Figure 2(A) includes, in addition to the light-emitting layer 130, a hole injection layer 111, and It has functional layers such as a pore transport layer 112, an electron transport layer 118, and an electron injection layer 119.

[0050] In this embodiment, of the pair of electrodes, electrode 101 is used as the anode, and electrode 10 Although we will describe it as 2 being the cathode, this is not the case for the configuration of the light-emitting element 150. Electrode 101 is the cathode, electrode 102 is the anode, and the layers between these electrodes are stacked in the reverse order. It may also be done as follows: from the anode side, a hole injection layer 111, a hole transport layer 112, and light emission. The layers 130, electron transport layer 118, and electron injection layer 119 should be stacked in that order.

[0051] Furthermore, in this embodiment, in Figure 2(A), the electrode 101 (anode) side is the light extraction side. As explained above, the configuration of the light-emitting element 150 is not limited to that. In other words, the light extraction side The electrode 102 (cathode) side may also be used, and light can be taken from both electrode 101 and electrode 102. You can release it.

[0052] Note that the configuration of the EL layer 100 is not limited to the configuration shown in Figure 2(A), and at least the light-emitting layer 130 has a hole injection layer 111, a hole transport layer 112, an electron transport layer 118, and an electron injection layer 130. Each layer 119 may or may not have a hole. Also, the EL layer 100 is a hole Or reduce the electron injection barrier, improve hole or electron transport, hole or electron To inhibit transport, or to suppress quenching by electrodes, to suppress exciton diffusion, The configuration may also include a functional layer that has functions such as being able to do the following. It may be a single layer or a configuration in which multiple layers are stacked.

[0053] Figure 2(B) is a schematic cross-sectional view showing an example of the light-emitting layer 130 shown in Figure 2(A). The light-emitting layer 130 shown in B) may have a guest material 131 and a host material 132. .

[0054] In order to efficiently obtain light from the light-emitting element 150, the light extraction efficiency of the light-emitting element 150 must be high. This is preferable. However, as mentioned above, organic EL elements are called evanescent modes. It is known that the light extraction efficiency decreases depending on the attenuation mode. For example, light-emitting element 1 In 50, when the light generated in the light-emitting layer 130 passes through or is reflected by the electrode 101, It is attenuated by the evanescent mode.

[0055] To reduce the attenuation of light due to the evanescent mode, the light-emitting layer 130 and the electrode 101 One method is to increase the thickness of the layer between the two, for example, the hole injection layer 111 or the hole transport layer 112. However, this configuration presents problems such as an increase in drive voltage and a rise in manufacturing costs. .

[0056] In the light-emitting element 150, the light generated in the light-emitting layer 130 is extracted to the outside, If a layer with a low refractive index exists before the light generated in the light-emitting layer 130 passes through the substrate 200, the light will not pass through. It is known that this improves extraction efficiency.

[0057] The light generated in the light-emitting layer 130 is extracted to the outside through the hole injection layer 111 and the hole transport layer. 112 passes through electrode 101 and substrate 200. Therefore, hole injection layer 111 or hole It is preferable that the refractive index of the transport layer 112 is low, especially the hole injection layer 111 that is in contact with the electrode 101. A low refractive index is preferable.

[0058] However, in many cases, the hole injection layer 111 has electron-accepting properties in order to obtain hole injection characteristics. The substance is mixed with an electron-donating organic compound. The electron-accepting substance is then refracted. Because many of the materials have a high refractive index, the refractive index of the hole injection layer 111 becomes high. It was difficult to obtain a layer with low refractive index while possessing pore-injection properties. Furthermore, electron-accepting properties and If the electron-donating substance is an organic compound, then the structure of the organic compound contains cyclohexane bone. It is known that the refractive index decreases when a saturated cyclic compound like a saturation compound is present, but in terms of heat resistance... There was a problem.

[0059] Here, the inventors have found that by using an organic compound with a low refractive index in the hole injection layer 111, Even when using a material with high electron-accepting properties and hole injection characteristics, it is possible to obtain a material with a low refractive index that has hole injection properties. We found that a layer can be created. Furthermore, the inventors have found that a tetraarylmethane skeleton can be formed. or having at least one of the tetraarylsilane skeletons and an electron-donating group By mixing an organic compound with a high refractive index and electron-accepting properties into the hole injection layer 111, We discovered that even when using such materials, it is possible to create layers with carrier transport properties while maintaining a low refractive index. Furthermore, it was discovered that the organic compound also has excellent heat resistance. The transition temperature (Tg) is preferably 100°C or higher.

[0060] The refractive index of the above-mentioned organic compound with a low refractive index is preferably 1 or more and 1.75 or less. Or more preferably 1 or more and 1.73 or less, and more preferably 1.70 or less. This makes it possible to obtain light-emitting elements with good light extraction efficiency.

[0061] Either the tetraarylmethane skeleton or the tetraarylsilane skeleton mentioned above, and electricity Organic compounds having a child-donating group preferably have a refractive index of 1 or more and 1.75 or less, and more preferably The value is 1 or more and 1.73 or less, more preferably 1.70 or less. This allows us to obtain a light-emitting element with good light extraction efficiency.

[0062] As described above, if a layer with a low refractive index exists between the light-emitting layer 130 and the substrate 200, the light extraction effect is reduced. The rate improves, but by introducing a layer with a low refractive index in addition to the hole injection layer 111 and hole transport layer 112... This increases the number of layers to be fabricated, making the process of fabricating the light-emitting element more complicated. Furthermore, in one embodiment of the present invention, a layer having a low refractive index and hole injection characteristics is fabricated. Therefore, it is possible to use the conventional fabrication process, that is, while maintaining the number of layers to be fabricated. This can improve the light extraction efficiency of light-emitting elements.

[0063] Similarly, in one embodiment of the present invention, a tetraarylmethane skeleton or tetraarylcy By using either one of the lan skeletons and an organic compound having an electron-donating group, Because it is possible to fabricate a layer with a low refractive index and hole injection characteristics, conventional fabrication methods Using a process, that is, without increasing the number of layers to be fabricated, the light extraction effect of the light-emitting element can be improved. The rate can be improved.

[0064] Furthermore, one aspect of the present invention relates to an EL layer between the anode and the cathode. Therefore, to form irregularities on the substrate It can be combined with other light extraction improvement technologies.

[0065] Furthermore, in one aspect of the present invention, an organic compound having electron-donating properties is used with an organic compound having a low refractive index. It is preferable to have this configuration. By having this configuration, the refractive index of the hole injection layer 111 is reduced. While doing so, the hole injection characteristics can be improved, and the drive has good light extraction efficiency. A low voltage light-emitting element can be provided. The organic compound has a tetraarylmethane skeleton. Alternatively, it is even more preferable to have a tetraarylsilane skeleton.

[0066] Furthermore, it is preferable that the refractive index of the hole injection layer 111 is lower than that of the light-emitting layer 130. This reduces the attenuation of light emitted from the light-emitting layer 130 due to evanescent waves. Yes, it is possible. Also, the refractive index of the hole injection layer 111 is lower than the refractive index of the hole transport layer 112. It is more preferable that the refractive index of the pore transport layer 112 is lower than that of the light-emitting layer 130. This reduces the refractive index step between the light-emitting layer 130 and the hole injection layer 111, Furthermore, the light extraction efficiency can be improved.

[0067] Furthermore, in order to suppress the waveguide mode of the EL layer, the layer through which the light generated in the light-emitting layer 130 passes is necessary. A smaller number is preferable. Therefore, it is desirable that the light-emitting layer 130 is in contact with the electrode 101. While this configuration is preferable in terms of output efficiency, it would have an impact on the carrier balance. The luminescence efficiency of the light-emitting layer 130 may decrease due to the plasmon effect. Therefore, The hole injection layer 111 and the hole transport layer 112 are necessary layers for the EL layer to function efficiently. Therefore, it is preferable that the hole injection layer 111 and the hole transport layer 112 are in contact. It is even more preferable that the transmitting layer 112 and the light-emitting layer 130 are in contact.

[0068] Furthermore, it is preferable that the refractive index of the hole injection layer 111 is lower than that of the electrode 101. This allows the relationship between the refractive index n HIL of the hole injection layer 111 and the refractive index n cat. of the electrode 101. Since the ratio is n cat. / n HIL > 1, light from the hole injection layer 111 to the electrode 101 Total internal reflection during passage can be suppressed. In other words, the waveguide mode can be suppressed. It can also suppress the attenuation of light caused by the evanescent mode resulting from reflection. Cut.

[0069] Furthermore, the refractive index of the hole injection layer 111 is preferably 1 or more and 1.80 or less. More preferably The value is 1 or more and 1.78 or less, more preferably 1 or more and 1.75 or less. This allows for good light extraction efficiency.

[0070] Furthermore, in the hole injection layer 111, an organic compound having electron-donating properties and an electron-accepting property It is preferable to mix the substances. By using this configuration, good hole injection characteristics can be obtained. can.

[0071] Here, the mixing ratio of the above-mentioned organic compound and the electron-accepting substance is such that the electron-accepting substance Preferably, the volume ratio of the substance is 0.01 or more and 0.3 or less relative to the organic compound. By using this composition, even if a substance with a high refractive index is used for the electron-accepting substance, the organic compound By using an organic compound with a low refractive index, a hole injection layer 111 with a low refractive index can be created. The inventors have found that it is possible to manufacture it.

[0072] The attenuation of light due to evanescent waves described above can also occur for light incident on electronic devices. For example, when an electronic device according to one aspect of the present invention is applied to a solar cell, Evanesse This suppresses the attenuation of light caused by ray waves, thereby improving the light confinement effect of the solar cell. This can be done. Therefore, the electronic device according to one aspect of the present invention is suitable for use in solar cells. It is possible. In this case, the functional layer 40 in the electronic device 50 shown in Figure 1 is active. You may substitute "layer," "light-absorbing layer," or "photovoltaic layer."

[0073] <Organic compounds used in the hole injection layer 111> Here, we will describe organic compounds that can be suitably used in the hole injection layer 111.

[0074] It is preferable to use an organic compound with a low refractive index in the hole injection layer 111. Here, The refractive index of this object is expressed by the Lorentz-Lorenz equation (equation (1)) shown below.

[0075]

number

[0076] Equation (2) can be obtained by transforming equation (1).

[0077]

number

[0078] In equations (1) and (2), n is the refractive index, α is the polarizability, N is the number of molecules per unit volume, and ρ is the density. degrees, N A is Avogadro's number, M is molecular weight, V0 is molar volume, and [R] represents atomic refraction.

[0079] From equation (2), in order to reduce the refractive index n, we can reduce φ, and from equation (1) To reduce φ, we need to reduce the atomic refraction [R]. That is, reduce the refractive index n. To achieve this, one should select an organic compound that has a small atomic refraction [R].

[0080] Since the above formula is for polymers, when applied to low molecular weight compounds, the calculated value will be different. Some discrepancies are expected, but the general trend is thought to be similar, so the hole The organic compound used in the injection bed 111 is selected to have a low atomic refraction [R]. It is preferable to select. Furthermore, it is preferable that the hole injection layer 111 has hole injection characteristics. Therefore, the organic compounds used in the hole injection layer 111 also have molecules that are aromatic compounds. It is more preferable that the organic compound has π-conjugation and electron-donating properties. This allows for the fabrication of a hole injection layer 111 with a low refractive index and excellent hole injection characteristics. ru.

[0081] Atomic refraction [R] refers to substituents containing fluorine, such as fluoro groups and trifluoromethyl groups, and cyclo The hexyl group and the bond via the aromatic ring are sp 3 The conjugation between aromatic rings, as exemplified by hybrid orbitals, is Organic compounds having a structure that is not alternating tend to be smaller. Because the conjugated system is not extended throughout the entire molecule, the atomic refraction [R] tends to be small. Therefore, the organic compound used in the hole injection layer 111 is an organic compound having the above substituents or bonds. It is preferable.

[0082] The organic compounds used in the hole injection layer 111 include aromatic amine skeletons, pyrrole skeletons, and thiophene. Organic compounds with a 3D skeleton, or bulky groups such as methyl groups, t-butyl groups, and isopropyl groups. Organic compounds having an aromatic ring with substituents can also be suitably used. These molecules possess a π-conjugated system and tend to have a low refractive index.

[0083] An example of a structure in which the conjugation between aromatic rings is broken in the aforementioned bond via aromatic rings is the following general example. Tetraarylmethane skeleton represented by formula (100), tetraarylmethane skeleton represented by general formula (101) Examples include arylsilane skeletons or cyclohexyl skeletons. Tetraarylmethane skeleton The tetraarylsilane skeleton has a low refractive index and better heat resistance compared to the cyclohexyl skeleton. Therefore, it can be suitably used in the hole injection layer 111. Furthermore, it can be easily produced by vacuum deposition. Because it can form a thin film on the stool, it can be suitably used in electronic devices such as organic ELs. can.

[0084] [ka]

[0085] Furthermore, it is preferable that the organic compound used in the hole injection layer 111 has electron-donating properties. Examples of skeletons with properties include aromatic meshes shown in the following general formulas (200) to (220). Examples include the π-frame and the π-electron-rich complex aromatic ring framework. In general formulas (210) to (213) X represents oxygen or sulfur.

[0086] [ka]

[0087] The aromatic amine skeleton mentioned above (specifically, for example, the triarylamine skeleton), π electron excess type heterogeneous aromatic ring skeletons (specifically, for example, furan skeletons, thiophene skeletons, pyrrole skeletons, aze) The ring having a pin skeleton or an acridine skeleton may have substituents. Examples include alkyl groups having 1 to 6 carbon atoms and cycloalkyl groups having 3 to 6 carbon atoms. You can also choose a group, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. Yes, it is possible. Specific examples of alkyl groups having 1 to 6 carbon atoms include, for example, a methyl group, etc. Tyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, Examples include n-hexyl groups. Also, cycloalkyl groups with 3 to 6 carbon atoms. Examples of cyclopropyl groups include, for instance, cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as the cyclohexyl group. Also, ants with 6 to 12 carbon atoms. Examples of phenyl groups include phenyl, naphthyl, and biphenyl groups. This can be achieved. Furthermore, the substituents may bond to each other to form a ring. For example, the carbon at position 9 in the fluorene skeleton has two phenyl groups as substituents. If such groups are present, the phenyl groups bond together to form a spirofluorene skeleton. Examples include cases where this is achieved. Furthermore, in the case of unsubstituted compounds, there are advantages in terms of ease of synthesis and the cost of raw materials. It is advantageous.

[0088] The above electron-donating skeletons are, as mentioned above, aromatic amine skeletons, pyrrole skeletons, and azepi It is preferable that the skeleton is an odd-membered ring skeleton such as an rhomboid or an acridine skeleton. These skeletons are electron-donating. Because the electrons are well-formed and the atomic refractive index [R] is low, having these skeletons in the molecule allows electrons to be formed. Organic compounds with excellent donor properties and low refractive index can be obtained.

[0089] Also, Ar 1 ~Ar 8 Each of these independently comprises an aryl group having 6 to 13 carbon atoms. This refers to an aromatic amine skeleton or π-electron peroxide represented by the above-mentioned general formulas (200) to (220). Represents a surplus heteroaromatic skeleton. The aryl group may have substituents, and these substituents are relative to each other. They may bond to form a ring. For example, the fluorenyl group at position 9 The carbon atom has two phenyl groups as substituents, and these phenyl groups are bonded together. Examples include cases where a spirofluorene skeleton is formed. C6 to C13 Examples of aryl groups include phenyl, naphthalenyl, and fluorenyl groups. For example, if the aryl group has substituents, then the substituents and For example, alkyl groups having 1 to 6 carbon atoms, and cycloalkyl groups having 3 to 6 carbon atoms. Alternatively, aryl groups with 6 to 12 carbon atoms can also be selected. Examples of alkyl groups with prime number 6 include, for example, methyl group, ethyl group, propyl group, and Examples include sopropyl group, butyl group, isobutyl group, tert-butyl group, and n-hexyl group. It is possible to do so. Furthermore, as specific examples of cycloalkyl groups having 3 to 6 carbon atoms, For example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, Examples include: Also, as aryl groups having 6 to 12 carbon atoms, for example Specific examples include the phenyl group and the naphthyl group.

[0090] Also, Ar 1 ~Ar 8 The aryl group represented by is, for example, the group represented by the following structural formula. It can be applied. However, the groups that can be used as aryl groups are limited to these. do not have.

[0091] [ka]

[0092] Also, Ar 1 ~Ar8 When it is an aryl group, the aryl group is substituted or unsubstituted a substituent with a relatively small π-conjugation system spread, such as an aryl group having 6 to 13 carbon atoms is preferred, and a substituted or unsubstituted phenyl group is more preferred. Substituents with a small π-conjugation system tend to have a small atomic refraction [R]. On the other hand, in organic compounds with a small π-conjugation system such as alkenes, since the carrier transport property is poor, they are not suitable for electronic devices. Therefore, an aryl group having 6 to 13 carbon atoms, particularly an organic compound such as a phenyl group, which has a carrier transport property and a small π-conjugation system, is preferred as the organic compound used in the hole injection layer 111. In addition, substituents of odd-membered rings are preferred because they have a small atomic refraction [R].

[0093] In general formulas (200) to (220), R 1 to R 11 each independently represents hydrogen , an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or also represents any one of a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. As the alkyl group having 1 to 6 carbon atoms specific examples include, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, an n-hexyl group and the like. Also, as the cycloalkyl group having 3 to 6 carbon atoms, specific examples include, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohe xyl group and the like. Also, as the aryl group having 6 to 13 carbon atoms specific examples include, for example, a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group and the like as specific examples. Furthermore, the above-mentioned aryl group and phenyl group may have substituents The substituents may also be bonded to each other to form a ring. The substituents may have 1 carbon atoms. Alkyl groups having up to 6 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, or 6 carbon atoms Aryl groups with up to 12 carbon atoms can also be selected. Alkyl groups with 1 to 6 carbon atoms. Specifically, examples of groups include methyl group, ethyl group, propyl group, isopropyl group, and b Examples include butyl groups, isobutyl groups, tert-butyl groups, and n-hexyl groups. Furthermore, specific examples of cycloalkyl groups having 3 to 6 carbon atoms include, for example, cyclo Examples include propyl groups, cyclobutyl groups, cyclopentyl groups, and cyclohexyl groups. Yes, it is possible. Also, examples of aryl groups having 6 to 12 carbon atoms include phenyl groups and na Phthyl groups and biphenyl groups can be given as specific examples.

[0094] Also, R 1 ~R 11 The hydrogen, alkyl, or aryl group represented by the following is an example: The groups represented by structural formulas (R-1) to (R-27) can be applied. These are not the only groups that can be used as an aryl or aryl group.

[0095] [ka]

[0096] Furthermore, in general formulas (200) to (220), Ar 9 ~Ar 13 is a carbon-numbered carbon-6 to carbon The number 13 represents an arylene group, and the arylene group may have substituents, and the substituents are They may bond to each other to form a ring. An example of this is the fluorenyl group The carbon at position 9 has two phenyl groups as substituents, and these phenyl groups are bonded together. Therefore, one example is when a spirofluorene skeleton is formed. (C6 to C6) Examples of the 13 allylene groups include phenylene groups, naphthalene diyl groups, and biphenylene groups. Specific examples include the arn group and the fluororangeyl group. If the group has substituents, the substituents may be alkyl groups having 1 to 6 carbon atoms, carbon atoms, etc. Cycloalkyl groups with 3 to 6 carbon atoms, or aryl groups with 6 to 12 carbon atoms. It can be selected. Specifically, alkyl groups having 1 to 6 carbon atoms include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, ter Examples include t-butyl groups and n-hexyl groups. Also, groups with 3 to 6 carbon atoms. Examples of cycloalkyl groups include, for example, cyclopropyl group, cyclobutyl group, Examples include cyclopentyl groups and cyclohexyl groups. Also, groups with 6 or more carbon atoms. Examples of aryl groups with a prime number of 12 include the phenyl group, naphthyl group, and biphenyl group. This can be given as a concrete example.

[0097] Also, Ar 9 ~Ar 13 The arylene group represented by the following structural formula (Ar-1 2) Groups represented by (Ar-25) can be applied. Note that Ar 9 ~Ar 1 3 These are not the only groups that can be used as such.

[0098] [ka]

[0099] As described above, the organic compound used for the hole injection layer 111 is preferably an organic compound having a tetraarylmethane skeleton or a tetraarylsilane skeleton and electron donating properties. As an example of the organic compound, 9-(4-t-butylphenyl)-3,4-ditrityl-9H-carbazole (abbreviation: CzC), 9-(4-t-butylphenyl)-3,4-ditriphenylsilyl-9H-carbazole (abbreviation: CzSi), 4,4,8,8,-12,12-hexa-p-tolyl-4H-8H-12H-12C-aza-dibenzo[cd,mn]picene (abbreviation: FATPA), 4,4'-bis(dibenzazepin-1-yl)-biphenyl (abbreviation: BazBP), 4,4'-bis(dihydro-dibenzazepin-1-yl)-biphenyl (abbreviation: HBazBP), 4,4'-(diphenylmethylene)bis(N,N-diphenylamine) (abbreviation: TCBPA), 4,4'-(diphenylsilanediyl)bis(N,N-diphenylamine) (abbreviation: TSBPA), etc. can be mentioned. These structural formulas are shown below. Also, the organic compound having a tetraarylmethane skeleton or a tetraarylsilane skeleton and electron donating properties is not limited to this. These structural formulas are shown below.

[0100]

[0101]

[0102]

Chemical formula

[0103] In addition, a low molecular weight organic compound can be preferably used for the electronic device according to one aspect of the present invention. By using a low molecular weight organic compound, all the layers included in the EL layer 100 can be formed by vacuum evaporation, so that the manufacturing process can be simplified.

[0104] <<Improved light extraction efficiency through adjustment of optical path length>> Furthermore, in an electronic device according to one aspect of the present invention, by controlling the optical path length, further light Extraction efficiency can be improved. Of the light emitted from the light-emitting layer 130, the desired wave can be extracted. It can efficiently extract long-range light.

[0103] For example, to efficiently extract light of a desired wavelength (wavelength: λ) from the light-emitting layer 130 Therefore, light of a desired wavelength from the light-emitting layer 130 can be obtained from the interface between the electrode 101 and the hole injection layer 111. The optical distance to the region (emission region 134) is (2m'-1)λ / 4 (where m' is a natural number). It is preferable to adjust it so that it is in the vicinity of ). Note that the light-emitting region referred to here is the light-emitting layer 13 This shows the recombination region between holes and electrons at 0.

[0104] By performing such optical adjustments, the attenuation of light due to evanescent mode is reduced. This allows for improved light extraction efficiency from the light-emitting layer 130.

[0105] Furthermore, the interface between the substrate 200 and the electrode 101 and the region of the light-emitting layer 130 where light of a desired wavelength can be obtained ( The optical distance to the luminescent region (134) is adjusted to be in the vicinity of mλ / 2 (where m is a natural number). It is preferable to adjust the optical settings in this way. This reduces the attenuation of light, thereby improving the light extraction efficiency from the light-emitting layer 130. It is possible.

[0106] To perform the above optical adjustment, the film thickness of the hole injection layer 111 or the hole transport layer 112 is adjusted. However, if the refractive index of the hole injection layer 111 is high, the optical path length tends to be longer. Therefore, if it is difficult to adjust the optical path length, or if the thickness of the hole injection layer 111 increases, the driving voltage will rise. This may occur. However, in one aspect of the present invention, the hole injection layer 111 has a low refractive index. Therefore, the optical path length can be easily controlled, and the film thickness can be reduced. In addition to improving the light extraction efficiency from 130, it also simplifies the manufacturing process of light-emitting elements and reduces A light-emitting element with a driving voltage can be realized.

[0107] The attenuation of light due to evanescent waves described above can also occur for light incident on electronic devices. For example, when an electronic device according to one aspect of the present invention is applied to a solar cell, Evanesse Because the attenuation of light due to ray waves can be suppressed, the light confinement effect of the organic solar cell is enhanced. It can be improved. Therefore, the electronic device according to one aspect of the present invention is suitable for solar cells. It can be used for this purpose. In this case, the functional layer 40 in the electronic device 50 shown in Figure 1 is You can substitute "active layer" for "active layer."

[0108] Furthermore, in the above structure, by adjusting the optical path length of the light-emitting element to the desired wavelength λ of light, the light can be effectively utilized. We have explained a configuration for efficient extraction, and now we will explain an example of its application to solar cells using Figure 1. To clarify, a pair of optical paths are set such that the optical path length is different from the wavelength λ' of the light incident on the electronic device 50. In Figure 1, it is preferable to adjust the film thickness between the electrodes by adjusting the film thickness of the organic semiconductor layer 20. i. By using this configuration, the light incident on the electronic device 50 can be efficiently directed into the electronic device 50. It can be confined in. Furthermore, in an electronic device according to one aspect of the present invention, Evan Because it can suppress the attenuation of light caused by sent waves, it can achieve a more efficient light confinement effect. It can be obtained.

[0109] <Material> Next, details of the components of a light-emitting element, which is an example of an electronic device according to one aspect of the present invention, will be described below. Hereinafter, the description will be given.

[0110] ≪Light-emitting layer≫ The light-emitting layer 130 preferably has at least a host material 131 and further has a guest material 132. Also, as will be described later, the host material 131 may have an organic compound 131_1 and an organic compound 131_2. In the light-emitting layer 130, the host material 131 is present in the largest amount by weight ratio and the guest material 132 is dispersed in the host material 131. When the guest material 132 is a fluorescent compound, the S1 level of the host material 131 (organic compound 131_1 and organic compound 131_2) of the light-emitting layer 130 is preferably higher than the S1 level of the guest material (guest material 13 2) of the light-emitting layer 130. Also, when the guest material 132 is a phosphorescent compound, the T1 level of the host material 131 (organic compound 131_1 and organic compound 131_2 ) of the light-emitting layer 130 is preferably higher than the T1 level of the guest material (guest material 132) of the light-emitting layer 130. This is preferable.

[0111] The organic compound 131_1 preferably has a heteroaromatic skeleton having 1 to 20 carbon atoms containing two or more nitrogens. In particular, it is preferably a compound having a pyrimidine skeleton and a triazine skeleton. As the organic compound 131_1, a material having higher electron transportability than holes (electron transport material) can be used, and it preferably has an electron mobility of 1×10 cm -6 2 / Vs or more. This is preferable.

[0112] Specifically, for example, 4,6-bis[3-(phenanthren-9-yl)phenyl]pyr Midine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl) Phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-( 9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm) Heterocyclic compounds having a diazine skeleton, such as 2-{4-[3-(N-phenyl-9H- Carbazo-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diph Enyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-{3-[3-(ben Zo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diph Enyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2,4,6-tris( Biphenyl-3-yl)-1,3,5-triazine (abbreviation: T2T), 2,4,6-tri Su[3'-(pyridine-3-yl)-biphenyl-3-yl]-1,3,5-triazine (Abbreviation: TmPPPyTz), 9-[4-(3,5-diphenyl-1H-1,2,4-to Riazol-1-yl)phenyl-9H-carbazole (abbreviation: CzTAZ(1H)) Heterocyclic compounds having triazine, pyrimidine, or triazole skeletons are safe It is stable and reliable, which is desirable. Furthermore, heterocyclic compounds having this skeleton have electron transport properties. It has a high coefficient of action and also contributes to reducing the drive voltage. The materials described here are mainly 1 × 10⁻¹⁶ -6 cm 2 / V It is a substance with an electron mobility of s or higher. Furthermore, it is a substance that has higher electron transport capabilities than holes. If so, you may use substances other than those listed above.

[0113] Furthermore, organic compound 131_1 includes pyridine derivatives, pyrazine derivatives, and pyridazine derivatives. Conductors, bipyridine derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenan Compounds such as throline derivatives and purine derivatives can also be used. The object is 1 x 10 -6 cm 2 It is preferable that the material has an electron mobility of / Vs or higher.

[0114] Specifically, for example, vasophenanthroline (abbreviation: BPhen), vasocuproin ( Heterocyclic compounds having a pyridine skeleton, such as (abbreviation: BCP), and 2-[3-(dibenzothio) Fen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPD) Bq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl] Dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'- (9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxa Phosphorus (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazo [Il-9-yl]phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq- III) 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h] Quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothioff) [phenyl-4-yl]phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDB) q-II), 2-[3-(3,9'-bi-9H-carbazol-9-yl)phenyl]di Benzo[f,h]quinoxaline (abbreviation: 2mCzCzPDBq), and other pyrazine skeletons Hetero-aromatic ring compounds and 3,5-bis[3-(9H-carbazol-9-yl)phen [Lu]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)f Heterocyclic compounds with a pyridine skeleton, such as [enyl]benzene (abbreviated as TmPyPB), are also used. It can be. Also, poly(2,5-pyridinediyl) (abbreviation: PPy), poly[( 9,9-Dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl) )] (abbreviation: PF-Py), poly[(9,9-dioctylfluorene-2,7-diyl) -co-(2,2'-bipyridine-6,6'-diyl) (abbreviation: PF-BPy) High-molecular-weight compounds can also be used. Furthermore, any material with higher electron transport capabilities than holes can also be used. However, other substances may be used.

[0115] Organic compound 131_2 is a heteroaromatic bone with 1 to 20 carbon atoms containing two or more nitrogen atoms. It is preferable that it has a morphological structure. In particular, a nitrogen-containing heterogeneous five-membered ring skeleton is preferred. For example, an imidazole skeleton. Examples include triazole skeletons and tetrazole skeletons. Also, organic compounds 131_ 2. Materials that are more efficient at transporting holes than electrons (hole-transporting materials) can be used. , 1 x 10 -6 cm 2 It is preferable that the material has a hole mobility of / Vs or greater. The hole-transporting material may be a polymer compound.

[0116] Specifically, for example, 3-(4-biphenylyl)-4-phenyl-5-(4-tert- Butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 9-[4-(4,5- Diphenyl-4H-1,2,4-triazole-3-yl)phenyl]-9H-carbazo benzenetriyl (abbreviation: CzTAZ1), 2,2',2''-(1,3,5-benzenetriyl) RIS(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(di Benzothiophen-4-yl)phenyl]-1-phenyl-1H-benzoimidazole ( Abbreviations such as mDBTBIm-II can be used.

[0117] Organic compound 131_2 includes other nitrogen-containing heterogeneous five-membered ring skeletons or tertiary amine skeletons. Compounds having a pyrrole skeleton or aromatic compounds can also be suitably used. Specifically, compounds having a pyrrole skeleton or aromatic compounds. Examples include the mine skeleton. For instance, indole derivatives, carbazole derivatives, and triaryls. Examples include amine derivatives. Furthermore, as for organic compounds 131_2, holes are more important than electrons. Highly transportable materials (hole transportable materials) can be used, 1 × 10 -6 cm 2 / Vs It is preferable that the material has the above hole mobility. Furthermore, the hole transporting material is a polymer. It may also be a compound.

[0118] These materials with high hole transport capabilities include, specifically, aromatic amine compounds such as N, N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DT) DPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenyl Mino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl [amino]phenyl]-N,N'-diphenyl-(1,1'-biphenyl)-4,4' -Diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophen) Examples include [phenyl]-N-phenylaminobenzene (abbreviation: DPA3B), etc. .

[0119] Furthermore, as a carbazole derivative, specifically, 3-[N-(4-diphenylamino Phenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1) ), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9 -Phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenyl (Aminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation) :PCzTPN2), 3-[N-(9-phenylcarbazol-3-yl)-N-phenyl Luamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N- (9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarb Zol (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcate Luvazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) , 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (abbreviation: dm Examples include CBP, etc.

[0120] In addition, other carbazol derivatives include 4,4'-di(N-carbazolyl)bife Nyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]bene Zen (abbreviation: TCPB), 9-[4-(10-phenyl-9-antryl)phenyl]- 9H-carbazol (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phen [Nyl]-2,3,5,6-tetraphenylbenzene, etc., can be used.

[0121] Also, N,N-diphenyl-9-[4-(10-phenyl-9-antryl)phenyl ]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl- 9-Anthryl)triphenylamine (abbreviation: DPhPA), 4-(9H-carbazole) -9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9-antryl)f [phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), N,9-diphenyl -N-{4-[4-(10-phenyl-9-antryl)phenyl]phenyl}-9H- Carbazole-3-amine (abbreviation: PCAPBA), N,9-diphenyl-N-(9,1 0-Diphenyl-2-anthryl)-9H-carbazol-3-amine (abbreviation: 2PCA) PA), 9-phenyl-3-[4-(10-phenyl-9-antryl)phenyl]-9 H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl Nyl-9-antryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), N, N,N',N',N'',N'',N''',N'''-Octaphenyldibenzo[g, p] Chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 1,1-bis- (4-bis(4-methylphenyl)-aminophenyl)-cyclohexane (abbreviation: T APCs (Advanced Printing Controls) and the like can be used.

[0122] Also, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphen Nylamine (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl [amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( Abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis High molecular weight compounds such as (phenyl)benzidine (abbreviated as Poly-TPD) can also be used. can.

[0123] Furthermore, as a material with high hole transport properties, for example, 4,4'-bis[N-(1-naphthium [N-phenylamino]biphenyl (abbreviated as NPB or α-NPD) or N,N'- Bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4, 4'-Diamine (abbreviation: TPD), 4,4',4''-Tris(carbazole-9-yl) ) Triphenylamine (abbreviation: TCTA), 4,4',4''-tris[N-(1-naphtholamine) [1'-TNATA]-N-phenylaminotriphenylamine (abbreviation: 1'-TNATA), 4,4 ',4''-Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDAT) A) 4,4',4''-Tris[N-(3-methylphenyl)-N-phenylamino] Triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9' -bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4 -phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)trife Nylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluorene-2) -yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl -9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine N (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H- Fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl [Nylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl) Triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9- Phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1B) P), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl) Triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''- (9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBN) BB), 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl) Min (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl) -N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N', N''-triphenyl-N,N',N''-tris(9-phenylcarbazole-3-I) (L)Benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl) -N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-cal Bazole-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl) -N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-di Methyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 9,9-dimethyl-N -phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl] Luolen-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl -9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-a Min (abbreviation: PCBASF), 2-[N-(9-phenylcarbazole-3-yl)-N -phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7-bi S[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'- Bifluoren (abbreviation: DPA2SF), N-[4-(9H-carbazole-9-yl) [phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'- Bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-di Aromatic amine compounds such as methylfluorene-2,7-diamine (abbreviation: YGA2F), etc. It can also be used. Furthermore, 3-[4-(1-naphthyl)-phenyl]-9-phenyl -9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthril)-pheni [Lu]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3,3'-bis(9- Phenyl-9H-carbazole (abbreviation: PCCP), 1,3-bis(N-carbazolyl) )Benzene (abbreviation: mCP), 3,6-bis(3,5-diphenylphenyl)-9-phenyl Nilcarbazole (abbreviation: CzTP), 3,6-di(9H-carbazole-9-yl)- 9-phenyl-9H-carbazole (abbreviation: PhCzGI), 2,8-di(9H-carbazole) Amine compounds such as zole-9-yl)-dibenzothiophene (abbreviation: Cz2DBT), Lubazole compounds and the like can be used. Among the compounds mentioned above, pyrrol skeletons and aromatic compounds can be used. Compounds having a fragrance amine skeleton are stable, reliable, and therefore preferable. Compounds possessing this property exhibit high hole transportability and contribute to reducing the driving voltage.

[0124] Furthermore, in the light-emitting layer 130, there are no particular limitations on the guest material 132, but fluorescence Examples of compounds include anthracene derivatives, tetracene derivatives, chrysene derivatives, and phenanthochemicals. Pyrene derivatives, pyrene derivatives, perylene derivatives, stilbene derivatives, acridone derivatives, Marine derivatives, phenoxazine derivatives, phenothiazine derivatives, etc. are preferred, for example: The following substances can be used.

[0125] Specifically, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2 ,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl -9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2) BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorine) [Len-9-yl]phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn) N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H -Fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMem FLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl) )phenyl]-N,N'-bis(4-tert-butylphenyl)pyrene-1,6-dia Min (abbreviation: 1,6tBu-FLPAPrn), N,N'-diphenyl-N,N'-bis [4-(9-phenyl-9H-fluoren-9-yl)phenyl]-3,8-dicyclophenyl Xylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'-bi Su[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbe n-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl) -4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA) , 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-ant) Lyl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4- (10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviated) Name: 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: PCBAPA), N,N' '-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene) Bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPAB) PA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl) [enyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9 ,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1 ,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N '',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10 ,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl -2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2 PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-ant [Lyl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPh) A) N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl -1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1 '-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1, 4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-bis( (phenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-f Phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenyl Luanthracene-9-amine (abbreviation: DPhAPhA), Coumarin 6, Coumarin 545T N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 2,8-di-te rt-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyl Lutetracene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl Lu-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2- [4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yly Dene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3 ,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-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-meth (p) acenaphtho[1,2-a]fluorantene-3,10-diamine (abbreviation: p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethicone)] Ru-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl )Ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI) , 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3, 6,7-Tetrahydro-1H,5H-Benzo[ij]quinoridine-9-yl)ethenyl -4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2, 6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-i (Liden)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8- Methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H -Benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene} Ropanedinitrile (abbreviation: BisDCJ™), 5,10,15,20-tetraphenyl Bisbenzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene These are some examples.

[0126] Guest material 132 (phosphorescent compound) can be iridium, rhodium, or platinum-based. Examples include organometallic complexes or metal complexes, among which organoiridium complexes, for example, iridium Um-based orthometallic complexes are preferred. 4H-triazo is a suitable ligand for orthometallation. 1H-triazole ligand, 1H-triazole ligand, imidazole ligand, pyridine ligand, pyrimi Examples include din ligands, pyrazine ligands, or isoquinoline ligands. Metal complexes Examples include platinum complexes containing porphyrin ligands.

[0127] Examples of substances that have a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo Ru-3-il-κN 2 ]phenyl-κC}iridium(III) (abbreviation: Ir(mpp) tz-dmp)3), Tris(5-methyl-3,4-diphenyl-4H-1,2,4-) Ryasolato) Iridium(III) (abbreviation: Ir(Mptz)3), Tris[4-(3- [Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato] Lydium(III) (abbreviation: Ir(iPrptz-3b)3), Tris[3-(5-Bif [Phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridi Um(III) (abbreviation: Ir(iPr5btz)3), a 4H-triazole skeleton. organometallic iridium complexes having, or tris[3-methyl-1-(2-methylphenyl) -5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir (Mptz1-mp)3), Tris(1-methyl-5-phenyl-3-propyl-1H- 1,2,4-Triazolat) Iridium(III) (Abbreviation: Ir(Prptz1-Me) 3) Organometallic iridium complexes having a 1H-triazole skeleton, or fac-tri S[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazo-l] Rydium(III) (abbreviation: Ir(iPrpmi)3), Tris[3-(2,6-dimethyl Iridium (I)-7-methylimidazo[1,2-f]phenantridinato]iridium II) (abbreviation: Ir(dmpimpt-Me)3), Tris{2-[1-(4-cyano- 2,6-Diisobutylphenyl)-1H-Benzimidazole-2-yl-κN3 ]fe Like yl-κC}iridium(III) (abbreviation: Ir(pbi-diBuCNp)3) organometallic iridium complexes having an imidazole skeleton, and bis[2-(4',6'-diph Luorophenyl)pyridinate-N,C 2’ Iridium(III) tetrakis (1-pyra) Zolyl) Borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl) Pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), Bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C 2 ’ Iridium(III) picolinate (abbreviation: Ir(CF3ppy)2(pic)), Bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ ]iridium( III) Compounds having an electron-withdrawing group, such as acetylacetonate (abbreviation: Fir(acac)) Examples include organometallic iridium complexes with phenylpyridine derivatives as ligands. Among them, the 4H-triazole skeleton, 1H-triazole skeleton, and imidazole skeleton Organometallic iridium complexes with a nitrogen-containing five-membered heterocyclic skeleton exhibit high triplet excitation energy. It is particularly preferable because it possesses ghee, and also offers excellent reliability and luminous efficiency.

[0128] Furthermore, examples of substances that have a green or yellow emission peak include tris(4-methyl Iridium(III) (abbreviation: Ir(mppm)3), 6-phenylpyrimidinato Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm)3), (acetylacetonate)bis(6-methyl-4-phenylpyryl) Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetyl Luacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium III) (Abbreviation: Ir(tBuppm)2(acac)), (acetylacetonato)bis [4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation) :Ir(nbppm)2(acac)),(acetylacetonato)bis[5-methyl-6 -(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis{4,6-dimethicone} Lu-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN 3 ] Phenyl- κC} Iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), ( Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Abbreviation: Organometallic irritants with a pyrimidine skeleton, such as Ir(dppm)2(acac) Dium complexes, and (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetyl Luacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridi Pyrazine bones like Um(III) (abbreviation: Ir(mppr-iPr)2(acac)) iridium organometallic complexes with a specific classification, and tris(2-phenylpyridinato-N,C) 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinate-N) ,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(ac) ac)), bis(benzo[h]quinolinate)iridium(III)acetylacetonate (Abbreviation: Ir(bzq)2(acac)), Tris(benzo[h]quinolinato)iridiu Mu(III) (abbreviation: Ir(bzq)3), Tris(2-phenylquinolinato-N,C) 2 ’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinolinazole- N,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(pq)2(ac) Organometallic iridium complexes having a pyridine skeleton, such as ac)), and bis(2,4-diph Enyl-1,3-oxazolato-N,C 2’ Iridium(III) Acetylaceton (abbreviation: Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenicol) [Phenyl]pyridinate-N,C 2’ Iridium(III) acetylacetonate ( Abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazolat -N,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(a) In addition to organometallic iridium complexes such as CAC, there are also tris(acetylacetonate)(monophenate). Nanthroline terbium(III) (abbreviation: Tb(acac)3(Phen)) Examples include rare earth metal complexes. Among those mentioned above, organometallic ylids having a pyrimidine skeleton are particularly noteworthy. Dium complexes are particularly preferred because they offer outstanding reliability and luminous efficiency.

[0129] Furthermore, examples of substances that have a yellow or red emission peak include (diisobutyryl Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II) I) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methyl [Phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5 mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl)pyrimid Nat] (dipivaloylmethanato) Iridium(III) (Abbreviation: Ir(d1npm)2) Organometallic iridium complexes having a pyrimidine skeleton such as dpm, and (acetylacet Tonato)bis(2,3,5-triphenylpyradinato)iridium(III) (abbreviation: I r(tppr)2(acac)), bis(2,3,5-triphenylpyrazinate)(dipy Valoylmethanato) Iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato] A pyrazine skeleton like lysium(III) (abbreviation: Ir(Fdpq)2(acac)) The organometallic iridium complexes and tris(1-phenylisoquinolinato-N,C) 2’ ) Iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinolinate) -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq)2( In addition to organometallic iridium complexes with a pyridine skeleton such as acac), 2, 3, 7, 8,12,13,17,18-Octaethyl-21H,23H-Porphyrin Platinum(II) Platinum complexes such as (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3-p Ropandionato (monophenanthroline) europium(III) (abbreviation: Eu(DB) M)3(Phen)), Tris[1-(2-tenoyl)-3,3,3-trifluoroacetate Tonato (monophenanthroline) europium(III) (abbreviation: Eu(TTA)3) Examples include rare earth metal complexes such as Phen). Among those mentioned above, the pyrimidine skeleton The organometallic iridium complex possesses outstanding reliability and luminescence efficiency, and is therefore particularly preferred. Furthermore, organometallic iridium complexes having a pyrazine skeleton can produce a red emission with good chromaticity. It is possible.

[0130] The light-emitting material included in the light-emitting layer 130 is capable of converting triplet excitation energy into light emission. A material is preferable. A material that can convert the triplet excitation energy into light emission is phosphorescent. In addition to chemical compounds, there are also thermally activated delayed fluorescence compounds. Ayed fluorescence (TADF) materials are an example. Therefore, phosphorescence Where it says "thermal-activated compound," you may substitute it with "thermal-activated delayed fluorescence material." Oh, thermally activated delayed fluorescence materials are materials with triplet excitation energy levels and singlet excitation energy levels. The difference is small, and the energy is transferred from the triplet excited state to the singlet excited state by reverse intersystem crossing. It is a material that has the function of converting. Therefore, it converts the triplet excited state into a small amount of thermal energy. Therefore, it is possible to upconvert to a singlet excited state (reverse intersystem crossing), and from the singlet excited state It can efficiently exhibit luminescence (fluorescence). Furthermore, thermally activated delayed fluorescence can be efficiently obtained. The conditions for this to occur are the energy levels of the triplet excitation energy level and the singlet excitation energy level. The difference is preferably greater than 0 eV and 0.2 eV or less, and more preferably greater than 0 eV and 0 One example is that the voltage is less than 0.1 eV.

[0131] When a thermally activated delayed fluorescence material is composed of only one type of material, for example, the following materials can be used. It is possible.

[0132] First, there are fullerenes and their derivatives, acridine derivatives such as proflavin, and eosin. It can be produced. Also, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S) n) Metals containing platinum (Pt), indium (In), or palladium (Pd), etc. Examples include metal-containing porphyrins. For example, protoporph Fluorine-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-fluoride Tin complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (Sn F2 (Hemato IX), coproporphyrin tetramethyl ester - tin fluoride Complex (SnF2(Copro III-4Me)), octaethylporphyrin-fluoride Tin complex (SnF2(OEP)), Ethioporphyrin-tin fluoride complex (SnF2(E Examples include tio I)) and octaethylporphyrin-platinum chloride complex (PtCl2OEP). It can be done.

[0133] Furthermore, as a thermally activated delayed fluorescence material composed of one type of material, a π-electron-rich complex atom is an example. Heterocyclic compounds having aromatic rings and π-electron-deficient heteroaromatic rings can also be used. Specifically is 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3- a)Carvazo-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol [9-yl]phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PC) CzPTzn), 2-[4-(10H-phenoxazine-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 Ru-1,2,4-Triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl- 9H-acridine-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN) , bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (Abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine] Examples include -9,9'-anthracene]-10'-one (abbreviated as ACRSA). Because the cyclic compounds have π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings, High transportability and hole transportability are desirable. In particular, a skeleton having a π-electron-deficient heteroaromatic ring is preferred. Among these, diazine skeletons (pyrimidine skeletons, pyrazine skeletons, pyridazine skeletons), or tri The azine skeleton is preferred because it is stable and reliable. Furthermore, the π-electron-rich heteroaromatic ring is also preferred. Among the skeletons it possesses, the acridine skeleton, phenoxazine skeleton, thiophene skeleton, and furan skeleton are particularly noteworthy. The pyrrole skeleton is stable and reliable, therefore any of the skeletons can be selected. It is preferable to have one or more of these. The pyrrole skeleton is indole. The skeleton, the carbazole skeleton, and 3-(9-phenyl-9H-carbazole-3-yl)- A 9H-carbazole skeleton is particularly preferred. Note that π-electron-rich heteroaromatic rings and π-electron-deficient rings are also preferred. Substances directly bonded to a type of heteroaromatic ring exhibit both donor and π-electron-deficient properties for π-electron-rich heteroaromatic rings. Both the acceptor properties of the complex aromatic ring are strong, and the energy levels of the singlet excited state and the triplet excited state are also strong. This is particularly preferable because it reduces the energy level difference from the initial state's energy level.

[0134] Furthermore, in the light-emitting layer 130, materials other than the host material 131 and the guest material 132 are used. It's okay to have it.

[0135] There are no particular limitations on the materials that can be used for the light-emitting layer 130, but for example, ant spiral derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g, Examples include condensed polycyclic aromatic compounds such as p]chrysene derivatives, specifically 9,10-diph Phenylanthracene (abbreviation: DPAnth), 6,12-dimethoxy-5,11-diphenylanthracene Nyl chrysene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: D PPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert -butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9, 9'-Biantril (abbreviation: BANT), 9,9'-(Stilben-3,3'-Zil) Diphenanthrene (abbreviation: DPNS), 9,9'-(stilben-4,4'-diyl)di Phenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation) Examples include (name: TPB3). Furthermore, from among these and known substances, the above Singlet or triplet excitation energy levels higher than the excitation energy levels of guest material 132 One or more materials having excitation energy levels can be selected and used.

[0136] Furthermore, for example, a compound having a heteroaromatic skeleton such as an oxadiazole derivative is used in the light-emitting layer 1. It can be used in 30. Specifically, for example, 2-(4-biphenylyl)-5-(4 -tert-butylphenyl)-1,3,4-oxadiazol (abbreviation: PBD), and 1 ,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazolu- 2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-o Xadiazo-l-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 4, 4'-Bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) Examples of heterocyclic compounds include the following.

[0137] Furthermore, metal complexes containing heterocyclic rings (for example, zinc and aluminum-based metal complexes) emit light. It can be used in layer 130. For example, quinoline ligand, benzoquinoline ligand, oxy Examples include metal complexes having a sazole ligand or a thiazole ligand. Specifically, For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tri (4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), (10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2) ), bis(2-methyl-8-quinolinolate)(4-phenylphenolate)aluminum ( III) (Abbreviation: BAlq), Bis(8-quinolinolato)zinc(II) (Abbreviation: Znq) Examples include metal complexes having a quinoline skeleton or a benzoquinoline skeleton. In addition, bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviation: ZnP) BO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) (abbreviation: ZnB) Metal complexes with oxazole-based or thiazole-based ligands, such as TZ, are also used. It is possible.

[0138] The light-emitting layer 130 can also be composed of two or more layers. For example, the first When the first light-emitting layer and the second light-emitting layer are stacked in order from the hole transport layer side to form the light-emitting layer 130, A material having hole transport properties is used as the host material for the first light-emitting layer, and the host material for the second light-emitting layer This includes configurations that use materials with electron transport properties. Also, the first light-emitting layer and the second light-emitting layer The light-emitting material in the light layer may be the same material or different materials, and the same color light-emitting material may be emitted. Even if a material has the function of emitting light, it is a material that has the function of emitting light of different colors. It is also acceptable to use two light-emitting layers, each containing a light-emitting material that exhibits different colors of light emission. By using each of them, multiple light sources can be obtained simultaneously. In particular, the two light-emitting layers exhibit It is preferable to select the light-emitting material used in each light-emitting layer so that it becomes white due to the light emission.

[0139] The light-emitting layer 130 is produced by vapor deposition (including vacuum deposition), inkjet, coating, etc. It can be formed by methods such as labia printing. In addition to the materials mentioned above, quantum dots, etc. Even if it has an inorganic compound or polymer compound (oligomer, dendrimer, polymer, etc.) good.

[0140] ≪Hole Injection Layer≫ The hole injection layer 111 is a hole injection layer that receives holes from one of the pair of electrodes (electrode 101 or electrode 102). It has the function of promoting hole injection by reducing the injection barrier, for example, having electron-accepting properties. Formed by transition metal oxides, phthalocyanine derivatives, aromatic amines, heteropoly acids, etc. Examples of transition metal oxides include titanium oxide, vanadium oxide, tantalum oxide, Molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, chromic acid Examples include metal oxides, zirconium oxides, hafnium oxides, silver oxides, and the transition metal acid The phosphate exhibits excellent electron-accepting properties, allowing for easy film formation using vacuum deposition or wet deposition methods. It is preferable. Also, as phthalocyanine derivatives, phthalocyanine and metal phthalocyanine Examples include benzidine derivatives and phenylenediamine derivatives. Aromatic amines include benzidine derivatives and phenylenediamine derivatives. Examples include the body. High molecular weight compounds such as polythiophene and polyaniline may also be used. For example, a self-doped polythiophene such as poly(ethylenedioxythiophene) ) / Poly(styrene sulfonic acid) is a typical example. Also, as for heteropoly acids... Phosphorus-molybdic acid, phosphotungstic acid, silicic acid-molybdic acid, silicic acid-tungstic acid, etc. These include heteropoly acids and polymer compounds, which can be easily formed into films using wet methods. Therefore, it is preferable.

[0141] As the hole injection layer 111, a hole transport material with a low refractive index as described above, and the electrons as described above It is preferable to use a layer having a composite material of materials that exhibit acceptability. This allows for the formation of a layer with low refractive index while possessing hole injection and transport properties. As organic materials with good tolerance, TCNQ, F4TCNQ, and F6TCNNQ are preferably used. This is possible. Furthermore, lamination of a layer containing an electron-accepting material and a layer containing a hole-transporting material is possible. It may be used. Charge transfer between these materials occurs in a steady state or in the presence of an electric field. It is possible. Examples of organic materials that exhibit electron-accepting properties include the aforementioned TCNQ, F4TCNQ, and F6. In addition to TCNNQ, quinodimethane derivatives, chloranil derivatives, and hexaazatriphenyl Examples of organic acceptors include chloranil derivatives. Specifically, chloranil, 2, 3,6,7,10,11-Hexacyano-1,4,5,8,9,12-Hexaazatlif Compounds containing electron-withdrawing groups (halogen groups or cyano groups), such as phenylene (abbreviation: HAT-CN) It is a substance. Also, transition metals, such as titanium, vanadium, tantalum, molybdenum, and tan. Gusten, rhenium, ruthenium, chromium, zirconium, hafnium, silver, etc. and oxygen Substances containing titanium oxide, vanadium oxide, tanta rhenium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide chromium oxide, zirconium oxide, hafnium oxide, silver oxide, phosphomolybdic acid These include molybdenum bronze and tungsten bronze. Among them, molybdenum oxide is airborne. Among them, it is preferable because it is stable, has low hygroscopicity, and is easy to handle.

[0142] Furthermore, the low refractive index hole transport material used in the hole injection layer 111 is, as mentioned above, sp3 Organic compounds that have a structure in which the conjugation between aromatic rings is broken, such as bonds, or have bulky substituents Organic compounds having aromatic rings can be suitably used. Examples of skeletons with this structure include the tetraarylmethane skeleton and tetraarylsilane mentioned above. One example is the skeletal structure. However, on the other hand, such compounds tend to have poor carrier transport properties. It is located in the direction and is unsuitable for conventional hole injection layers. On the other hand, the transition metal and oxygen as described above The substance containing it is highly effective in enhancing hole injection, but it has the problem of having a high refractive index. However, as mentioned above, materials containing transition metals and oxygen are used as electron-accepting materials. When used in combination with a hole transport material with a low refractive index in the hole injection layer 111, the hole injection layer 1 It was found that hole injection and transport properties can be ensured while keeping the refractive index of 11 low. In other words, this configuration cancels out the disadvantages of both parties, allowing only the advantages to be realized. Yes, it is possible. This is because materials containing transition metal oxides have high electron-accepting properties, allowing for hole implantation with only small amounts of addition. This is likely due to the fact that sexual intercourse can be ensured.

[0143] As a hole-transporting material, a material with higher hole transport capabilities than electron transport can be used, ×10 -6 cm 2 It is preferable that the material has a hole mobility of / Vs or greater. As described above, the hole transport material is preferably one with a refractive index of 1 or more and 1.75 or less. More preferably, it is 1 to 1.73, and even more preferably 1 to 1.70. Specifically, aromatic amino acids were listed as hole transport materials that can be used in the light-emitting layer 130. Carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. can be used. However, it is particularly preferable that it has a heteroaromatic skeleton with 1 to 20 carbon atoms containing two or more nitrogen atoms. A nitrogen-containing heterogeneous five-membered ring skeleton is preferred. Furthermore, even if the hole transporting material is a polymer compound... good.

[0144] Other hole-transporting materials include aromatic hydrocarbons, such as 2-tert -butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2- tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3, 5-Diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9 ,10-Bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,1 0-Di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene Cene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAn) th), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA) , 2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthrace n, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7- Tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl Chil-9,10-di(2-naphthyl)anthracene, 9,9'-biantril, 10,1 0'-Diphenyl-9,9'-biantryl, 10,10'-bis(2-phenylphenyl Ru)-9,9'-Biantril, 10,10'-Bis[(2,3,4,5,6-Pentaf [phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, Examples include perylene and 2,5,8,11-tetra(tert-butyl)perylene. In addition, pentacene, coronene, etc. can also be used. -6 cm 2 Aromatic hydrocarbons having a hole mobility of / Vs or greater and having 14 to 42 carbon atoms. It is preferable to use

[0145] Furthermore, aromatic hydrocarbons may have a vinyl skeleton. Examples of group hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl (Abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] Examples include anthracene (abbreviated as DPVPA).

[0146] Also, 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl] Benzyl dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(be (Dibenzofuran) (abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II) ), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl) [phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl Lu-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation) :DBTFLP-IV), 4-[3-(triphenylene-2-yl)phenyl]dibenzo Thiophene compounds such as thiophene (abbreviation: mDBTPTp-II), furan compounds, and flu Orene compounds, triphenylene compounds, phenanthrene compounds, etc., can be used. Among the compounds mentioned above, pyrrole skeleton, furan skeleton, thiophene skeleton, aromatic amine skeleton Compounds having this structure are stable, reliable, and therefore preferable. The material has high hole transport properties and also contributes to reducing the drive voltage.

[0147] ≪Hole transport layer≫ The hole transport layer 112 is a layer containing a hole transportable material, and is an example of the material used for the hole injection layer 111. The hole transport material shown can be used. The hole transport layer 112 is in the hole injection layer 111. Because it has the function of transporting the injected holes to the light-emitting layer 130, the HOM of the hole injection layer 111 O(Highest Occupied Molecular Orbital) It is preferable to have the same or close HOMO level as the occupying orbital level.

[0148] Also, 1 x 10 -6 cm 2It is preferable that the substance has a hole mobility of / Vs or higher. However, other materials may be used as long as they have higher hole transport capabilities than electron transport. Furthermore, the layer containing the material with high hole transport properties may be a single layer, or a double layer consisting of the aforementioned material. You may stack more than this amount.

[0149] ≪Electron transport layer≫ The electron transport layer 118 passes through the electron injection layer 119 to the other of the pair of electrodes (electrode 101 or electron It has the function of transporting electrons injected from pole 102) to the light-emitting layer 130. Electron transport material For this purpose, materials with higher electron transport capabilities than holes can be used, resulting in 1 × 10⁻⁶ -6 cm 2 It is preferable that the material has an electron mobility of / Vs or higher. Examples of materials (materials with electron transport properties) include π-electron-deficient types such as nitrogen-containing heteroaromatic compounds. Hetero-aromatic compounds and metal complexes can be used. Specifically, they can be used in the light-emitting layer 130. Pyridine derivatives, bipyridine derivatives, and pyrimidines were listed as electron transport materials that can perform this function. Derivatives, triazine derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phena Introlin derivatives, triazole derivatives, benzimidazole derivatives, oxadiazole Examples include derivatives, but they have a heteroaromatic skeleton with 1 to 20 carbon atoms containing two or more nitrogen atoms. This is preferable. In particular, it is preferable that the compound has a pyrimidine skeleton and a triazine skeleton. It seems so. Also, 1 x 10 -6 cm 2 It is preferable that the material has an electron mobility of / Vs or higher. It seems so. Furthermore, any substance that has higher electron transport capabilities than holes will transport electrons. It may also be used as layer 118. Furthermore, the electron transport layer 118 may be not only a single layer, but also the above-mentioned material Two or more layers of the same material may be stacked on top of each other.

[0150] Other examples include metal complexes having heterocyclic rings, such as quinoline ligands and benzoquinoline. Examples include metal complexes having ligands, oxazole ligands, or thiazole ligands. Specifically, for example, tris(8-quinolinolato)aluminum(III) (abbreviation: A lq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Al mq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation) :BeBq2), bis(2-methyl-8-quinolinolate)(4-phenylphenolate) Luminium(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation) Examples include metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as Znq. In addition, bis[2-(2-benzoxazolyl)phenolate]zinc(II) Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) Metal complexes having oxazole or thiazole ligands (abbreviated as ZnBTZ) Other options can also be used.

[0151] Furthermore, a layer for controlling the movement of electron carriers is provided between the electron transport layer 118 and the light-emitting layer 130. It is also acceptable to use materials with high electron transport properties, as described above, and materials with high electron trapping properties. A layer to which a small amount of is added, thereby suppressing the movement of electron carriers, carrier balance This makes it possible to adjust the balance. With such a configuration, the electron transport properties of the electron transport material are correct. Problems that occur when the hole transport properties of a pore transport material are significantly higher than those of a pore transport material (e.g., low device lifetime) It is highly effective in suppressing (the lower part).

[0152] ≪Electron injection layer≫ The electron injection layer 119 promotes electron injection by reducing the electron injection barrier from the electrode 102. It has the function of being, for example, Group 1 metals, Group 2 metals, or their oxides and halides. Carbonates and the like can be used. In addition, the electron transport material shown above and the electron transport material therefor Composite materials exhibiting electron-donating properties can also be used. Examples of electron-donating materials include: Examples include Group 1 metals, Group 2 metals, or oxides thereof. Specifically These are lithium fluoride (LiF), sodium fluoride (NaF), and cesium fluoride (CsF). ), calcium fluoride (CaF2), lithium oxide (LiO2) x ) and other alkali metals Alkaline earth metals, or compounds thereof can be used. Also, fluoride Rare earth metal compounds such as bium (ErF3) can be used. Furthermore, electron injection layers can be used. An electride may be used in 119. For example, calcium Examples include substances obtained by adding a high concentration of electrons to a mixed oxide of aluminum and luminum. The injection layer 119 may be made of a material that can be used in the electron transport layer 118.

[0153] Furthermore, the electron injection layer 119 is a composite made by mixing an organic compound and an electron donor. Materials may be used. Such composite materials are created when electrons are released from the organic compound by an electron donor. Therefore, it exhibits excellent electron injection and electron transport properties. In this case, as an organic compound... Preferably, the material is one that is excellent at transporting the generated electrons, specifically, for example, the material described above. The electron transport layer 118 can be composed of materials (such as metal complexes or heteroaromatic compounds). The electron donor can be any substance that exhibits electron-donating properties towards organic compounds. Alkali metals, alkaline earth metals, and rare earth metals are preferred, as are lithium and sodium. Examples include cesium, magnesium, calcium, erbium, and ytterbium. Furthermore, alkali metal oxides and alkaline earth metal oxides are preferred, as are lithium oxides and calcium oxides. Examples include sium oxide and barium oxide. Also, Lewis plates such as magnesium oxide. Bases can also be used. Additionally, organic compounds such as tetrathiafulvalene (abbreviated as TTF) can be used. Objects can also be used.

[0154] Furthermore, the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer are, These methods include vapor deposition (including vacuum deposition), inkjet printing, coating, and gravure printing. It can be formed by the above-mentioned method. In addition, the light-emitting layer, hole injection layer, hole transport layer, electron In addition to the materials mentioned above, the transport layer and electron injection layer also contain inorganic compounds such as quantum dots and high-molecular-weight materials. Sub-compounds (oligomers, dendrimers, polymers, etc.) may also be used.

[0155] Quantum dots Quantum dots are semiconductor nanocrystals with a size of several nanometers to tens of nanometers, and have a size of 1 × 10⁻¹⁶ 3 Individual to 1 x 10 6 It is composed of about 100 atoms. The energy of a quantum dot depends on its size. Because of this shift, even quantum dots composed of the same material will emit different light waves depending on their size. The lengths are different. Therefore, by changing the size of the quantum dots used, light emission can be easily achieved. The wavelength can be changed.

[0156] Furthermore, quantum dots have a narrow peak width in their emission spectrum, resulting in emission with good color purity. It is possible. Furthermore, the theoretical internal quantum efficiency of quantum dots is said to be almost 100%. It accounts for a significant portion of the 25% of organic compounds that exhibit fluorescence, and the proportion of organic compounds that exhibit phosphorescence is much higher than that of organic compounds that exhibit phosphorescence. It is equivalent to a compound. Therefore, by using quantum dots as a light-emitting material... This allows us to obtain light-emitting elements with high luminescence efficiency. Moreover, quantum dots, which are inorganic materials, Furthermore, because of its excellent inherent stability, it is possible to obtain a desirable light-emitting element from the standpoint of lifespan. It is possible.

[0157] The materials that make up quantum dots include Group 14 elements, Group 15 elements, Group 16 elements, and composite Compounds consisting of elements from Group 14, and elements belonging to Groups 4 through 14 and Group 16. Compounds, compounds of Group 2 and Group 16 elements, compounds of Group 13 and Group 15 elements Compounds of Group 13 and Group 17 elements, compounds of Group 14 and Group 15 elements, Compounds of Group 11 and Group 17 elements, iron oxides, titanium oxides, chalcogenides Examples include semiconductor clusters and other similar devices.

[0158] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, and selenium sulfide. Lead, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, arsenic Indium, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, nitride Gallium, indium antimonide, gallium antimonide, aluminum phosphide, arsenide Aluminum, aluminum antimonide, lead selenide, lead telluride, lead sulfide, selenide Indium, indium telluride, indium sulfide, gallium selenide, arsenic sulfide, sele Arsenic arsenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, Bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium M, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide Aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride Beryllium, calcium sulfide, calcium selenide, calcium telluride, beryllium sulfide, Beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, Germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, acid Nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide Density, vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide Aluminum oxide, silicon nitride, germanium nitride, barium titanate, selenium and ammonium compounds. Compounds of lead and cadmium, compounds of indium, arsenic and phosphorus, cadmium, selenium and sulfur Compounds of cadmium, selenium, and tellurium, compounds of indium, gallium, and arsenic Compounds of indium, gallium, and selenium; compounds of indium, selenium, and sulfur; copper and Examples include compounds of ion and sulfur, and combinations thereof, but these include It is not limited. Furthermore, using so-called alloy-type quantum dots whose composition is expressed in any ratio. This is also good. For example, a quantum dot of cadmium, selenium, and sulfur alloy can be used by changing the elemental content ratio. By changing the emission wavelength, it is possible to alter the emission wavelength, making it one of the effective methods for obtaining blue light emission. There are two.

[0159] Quantum dot structures include core type, core-shell type, and core-multishell type. Either of these can be used, but another inorganic ion with a wider band gap can be used to cover the core. By forming a shell with the material, defects and dangling bones present on the nanocrystalline surface can be eliminated. The effects of the luminescence can be reduced. This greatly improves the quantum efficiency of the luminescence. It is preferable to use A-shell type or core-multi-shell type quantum dots. Examples of materials include zinc sulfide and zinc oxide.

[0160] Furthermore, because quantum dots have a high proportion of surface atoms, they are highly reactive and prone to aggregation. Therefore, a protective agent is attached to the surface of the quantum dot or a protective group is provided. It is preferable that the protective agent is attached or a protective group is provided. This prevents aggregation and increases solubility in the solvent. Furthermore, it reduces reactivity and electrical... It is also possible to improve stability. Examples of protective agents (or protective groups) include polio Polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene Polyoxyethylene alkyl ethers such as ethylene oleyl ether, tripropyl phosphate Fins, tributylphosphine, trihexylphosphine, trioctylphosphine, etc. Trialkylphosphines, polyoxyethylene n-octylphenyl ether, polio Polyoxyethylene alkylphenyl ethers such as xyethylene n-nonylphenyl ether Tel compounds, tri(n-hexyl)amines, tri(n-octyl)amines, tri(n-decyl) ) Tertiary amines such as amines, tripropylphosphine oxide, tributylphosphine Oxide, trihexylphosphine oxide, trioctylphosphine oxide, tridec Organophosphorus compounds such as sylphosphine oxide, polyethylene glycol dilaurate, Polyethylene glycol diesters such as polyethylene glycol distearate, and Organic nitrogen compounds such as nitrogen-containing aromatic compounds like pyridine, lutidine, colidine, and quinolines. , hexylamine, octylamine, decylamine, dodecylamine, tetradecylamine aminoalkanes such as hexadecylamine and octadecylamine, and dibutyl sulfide Dialkyl sulfides such as dipropyl sulfate, dipropyl sulfate such as dimethyl sulfoxide and dibutyl sulfoxide Organic sulfur compounds such as sulfur-containing aromatic compounds including sulfur sulfoxides and thiophenes, palmite Higher fatty acids such as tinic acid, stearic acid, and oleic acid, alcohols, and sorbitan fatty acid Polyesters, fatty acid-modified polyesters, tertiary amine-modified polyurethanes, polyethylene Examples include mines, etc.

[0161] Quantum dots have a larger band gap as their size decreases, so they can produce the desired wave. The size is adjusted appropriately to obtain sufficient light. Therefore, the emission of quantum dots shifts towards the blue side, that is, towards the higher energy side. By changing the size of the swatch, the wavelengths of the ultraviolet, visible, and infrared spectra can be adjusted. The emission wavelength can be adjusted across the region. The size (diameter) of the quantum dot is A range of 0.5 nm to 20 nm, preferably 1 nm to 10 nm, is commonly used. Furthermore, the narrower the size distribution of quantum dots, the narrower the emission spectrum becomes. This allows for emission with good color purity. Furthermore, the shape of the quantum dots is not particularly limited. It may be spherical, rod-shaped, disc-shaped, or in any other shape. Note that a rod-shaped quantum dot is a quantum Since the rod has the function of exhibiting directional light, quantum rods are used as light-emitting materials. By doing so, it is possible to obtain a light-emitting element with better external quantum efficiency.

[0162] By the way, in organic EL elements, the light-emitting material is often dispersed in the host material, and the light-emitting material By suppressing density quenching, the luminescence efficiency is increased. The host material is superior to the luminescent material. The material must have a doublet or triplet excitation energy level. In particular, when using blue phosphorescent materials as light-emitting materials, a triplet excitation energy greater than that is required. A host material is needed that possesses energy levels and is also superior in terms of lifespan, and its development is extremely difficult. Here, the quantum dots constitute the light-emitting layer using only quantum dots without using a host material. Because it can maintain its luminous efficiency, it is a desirable light-emitting element from the standpoint of lifespan. This can be obtained. When the light-emitting layer is formed using only quantum dots, the quantum dots are the core- A shell structure (including a core-multishell structure) is preferred.

[0163] When quantum dots are used as the light-emitting material for the light-emitting layer, the film thickness of the light-emitting layer is 3 nm to 100 nm. The n-thickness is preferably 10 nm to 100 nm, and the quantum dot content in the light-emitting layer is 1 to 1 The volume percentage is set to 00%. However, it is preferable to form the light-emitting layer using only quantum dots. When forming a light-emitting layer by dispersing the quantum dots as a light-emitting material in a host, the host material Disperse quantum dots in a suitable liquid medium, or dissolve the host material and quantum dots in a suitable liquid medium. Dispersed wet processes (spin coating, casting, die coating, blade coating) Coating method, roll coating method, inkjet method, printing method, spray coating method, curtain coating It can be formed by methods such as the stencil method or the Langmuir-Bludget method. Phosphorescent luminescent material For the light-emitting layer using the above wet process, vacuum deposition is also suitably used. It is possible.

[0164] Examples of liquid media used in wet processes include methyl ethyl ketone and cyclohexyl ester. Ketones such as xanone, fatty acid esters such as ethyl acetate, and halogens such as dichlorobenzene Aromatic hydrocarbons such as toluene, xylene, mesitylene, and cyclohexylbenzene. Hydrocarbons, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, dimethylform Organic solvents such as humic acid (DMF) and dimethyl sulfoxide (DMSO) can be used. Cut.

[0165] ≪A pair of electrodes≫ Electrodes 101 and 102 function as the anode or cathode of the light-emitting element. 101 and electrode 102 are made of metals, alloys, conductive compounds, and mixtures or laminates thereof. It can be formed using [a specific method / tool].

[0166] Either electrode 101 or electrode 102 is formed by a conductive material having the function of reflecting light. Preferably, this is done. The conductive material is aluminum (Al) or an Al-containing alloy. Examples include gold. Alloys containing Al include Al and L (where L is titanium (Ti) and neodymium). Includes (one or more of Nd, Ni, and La) Examples include alloys containing Al and Ti, or Al, Ni, and La. Aluminum has low resistance and high light reflectivity. Also, aluminum is found in the Earth's crust. Because it is abundant and inexpensive, using aluminum reduces the cost of manufacturing light-emitting devices. It can reduce the amount of silver (Ag), or Ag and N (N is yttrium). Y), Nd, Magnesium (Mg), Ytterbium (Yb), Al, Ti, Gallium ( Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), Tin (Sn), iron (Fe), nickel, copper (Cu), palladium (Pd), iridium (Ir ), or alloys containing one or more gold (Au) may be used. Examples of alloys include alloys containing silver, palladium, and copper, alloys containing silver and copper, and alloys containing silver and magnesium. Alloys containing nesium, alloys containing silver and nickel, alloys containing silver and gold, and alloys containing silver and ytterbium Examples include alloys containing tungsten, chromium (Cr), and molybdenum (Mo). ), transition metals such as copper and titanium can be used.

[0167] Furthermore, the light emitted from the light-emitting layer passes through one or both of electrodes 101 and 102. And it is removed. Therefore, at least one of electrode 101 or electrode 102 is transparent to light. Preferably, it is formed from a conductive material having a conductive function. The conductive material is preferably a conductive material. The light transmittance is 40% or more and 100% or less, preferably 60% or more and 100% or less, Its resistivity is 1 × 10⁻⁶ -2 Examples include conductive materials with a conductivity of Ω·cm or less.

[0168] Furthermore, electrodes 101 and 102 have the function of transmitting light and the function of reflecting light. It may be formed from a conductive material having a visible light reflectance of 20. The resistivity is between % and 80%, preferably between 40% and 70%, and its resistivity is 1 × 10⁻⁶. -2 Examples of conductive materials include those with a conductivity of Ω·cm or less. For example, conductive metals, alloys, and conductive materials. It can be formed using one or more types of chemical compounds. Specifically, for example, Indium tin oxide (ITO), silicon, or silicon oxide Indium tin oxide (abbreviated as ITSO), indium oxide-zinc oxide (Indi Indium-tin oxide containing titanium (indium zinc oxide), indium Metals such as indium oxide containing titanium oxide, tungsten oxide, and zinc oxide. Oxides can be used. Also, the degree to which light is transmitted (preferably 1 nm to 30 nm) A thin metal film with a thickness of m or less can be used. Examples of metals include Ag, or Alloys such as Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb can be used.

[0169] In this specification, etc., a material having the function of transmitting light is defined as a material having the function of transmitting visible light. Any material that has and is conductive is acceptable, for example, ITO as described above. In addition to oxide conductors, the collection includes oxide semiconductors or organic conductors containing organic materials. Examples of organic conductors include those obtained by mixing an organic compound with an electron donor. Examples include composite materials, such as composite materials formed by mixing organic compounds with electron acceptors. It is possible to use inorganic carbon-based materials such as graphene. Preferably, the ratio is 1 × 10⁻⁶. 5 Ω·cm or less, more preferably 1 × 10⁻⁶ 4 Ω·cm The following applies:

[0170] Furthermore, by stacking multiple of the above materials, one of the electrodes 101 and 102 can be made They may form both.

[0171] Furthermore, in order to improve the light extraction efficiency, the electrode having a light-transmitting function is brought into contact with the A material with a refractive index higher than that of the electrode may be formed. Such a material may transmit visible light. Any material that has the function of being conductive is acceptable, and even if it is a conductive material, it does not have that function. Other options include oxide conductors, oxide semiconductors, and organic materials. Examples of organic materials include the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, or electric Examples of materials used in the sub-injection layer include inorganic carbon-based materials and metals that are transparent to light. Thin films can also be used, and multiple layers of several nanometers to tens of nanometers in thickness may be stacked.

[0172] When electrode 101 or electrode 102 functions as a cathode, the work function is small. It is preferable that the material has a (3.8 eV or less) energy. For example, it is preferable that it has elements from Group 1 or Group 2 of the periodic table. Elements belonging to the group (alkali metals such as lithium, sodium, and cesium, calcium, stoichiometric compounds) Alkaline earth metals such as rontium, magnesium, etc., and alloys containing these elements (for example, Rare earth metals such as Ag and Mg, Al and Li, europium (Eu), Yb, and these rare earths Metal alloys, aluminum alloys, silver alloys, etc., can be used.

[0173] Furthermore, when electrode 101 or electrode 102 is used as the anode, the work function is large (4. It is preferable to use a material with a voltage of 0 eV or higher.

[0174] Furthermore, electrodes 101 and 102 are made of a conductive material that has the function of reflecting light and a material that transmits light. It may also be laminated with a conductive material having a function of passing through. In that case, electrode 101 and electrode 1 02 can resonate the light of a desired wavelength from each light-emitting layer, thereby intensifying the light of the desired wavelength. It is preferable because it can have a function to adjust the optical distance.

[0175] The methods for forming the film of electrodes 101 and 102 include sputtering, vapor deposition, printing, and coating. MBE (Molecular Beam Epitaxy), CVD, Pulse Ray The deposition method, ALD (Atomic Layer Deposition), etc., are used as appropriate. It is possible.

[0176] Circuit board Furthermore, a light-emitting element according to one aspect of the present invention is placed on a substrate made of glass, plastic, or the like. It is fine to manufacture it. In terms of the order in which it is manufactured on the substrate, it is fine to stack them in order from the electrode 101 side. You may also stack them sequentially starting from pole 102.

[0177] Examples of substrates on which a light-emitting element according to one aspect of the present invention can be formed include glass and quartz. , or plastic can be used. A flexible substrate may also be used. A substrate is a flexible substrate that can be bent, for example, polycarbonate Examples include plastic substrates made of nate, polyarylate, etc. Also, films, Inorganic vapor-deposited films can also be used. Note: The manufacturing process for light-emitting elements and optical elements. Anything other than these that functions as a support in the context is acceptable. Alternatively, Any device that has the function of protecting optical elements and other optical components is acceptable.

[0178] For example, in the present invention, a light-emitting element can be formed using various substrates. The type of substrate is not particularly limited. One example of such a substrate is a semiconductor substrate (e.g., a single crystal). Substrates (or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal Substrates, stainless steel substrates, substrates with stainless steel foil, tungsten Substrate, substrate having tungsten foil, flexible substrate, laminated film, fibrous Examples include paper or substrate films containing the material. An example of a glass substrate is barium phosphate. Examples include borosilicate glass, aluminoborsilicate glass, or soda-lime glass. Flexible Examples of substrates, laminated films, and base films include the following: For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Representative examples include polyethersulfone (PES) and polytetrafluoroethylene (PTFE). There are plastics. Or, for example, there are resins such as acrylic. Or, Examples include polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride. These include, for example, polyamide, polyimide, aramid, epoxy, and anomalous. Examples include metallized films or paper products.

[0179] Alternatively, a flexible substrate may be used as the substrate, and the light-emitting element may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting element. The release layer is provided on top of the light-emitting element. After partially or completely completing the child component, it is separated from the circuit board and used for transferring it to another circuit board. This allows for the transfer of light-emitting elements to substrates with poor heat resistance or flexible substrates. Oh, the aforementioned delamination layer has, for example, a laminated inorganic film structure of a tungsten film and a silicon oxide film. Configurations such as the one shown, or a configuration in which a resin film such as polyimide is formed on the substrate, can be used.

[0180] In other words, a light-emitting element is formed using one substrate, and then the light-emitting element is transferred to another substrate. The light-emitting element may be placed on a different substrate. An example of a substrate on which the light-emitting element is placed is the above In addition to the substrates mentioned above, there are also cellophane substrates, stone substrates, wood substrates, and cloth substrates (natural fibers (silk, cotton, Hemp), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate) (including t, cupro, rayon, recycled polyester, etc.), leather substrate, or rubber substrate. These substrates can be used to create light-emitting elements that are less prone to breakage and have high heat resistance. This can be a child, a lightweight light-emitting element, or a thinned light-emitting element.

[0181] Furthermore, a field-effect transistor (FET), for example, is formed on the aforementioned substrate, and the FET and The light-emitting element 150 may be fabricated on electrically connected electrodes. This allows the FET to This allows us to create an active-matrix type display device that controls the driving of the light-emitting element 150.

[0182] The following describes the components of a solar cell, which is an example of an electronic device according to one aspect of the present invention. To do so.

[0183] Solar cells can utilize the same materials that can be used in the aforementioned light-emitting elements. The carrier transport layer of the pond contains the aforementioned hole transport material and electron transport material, and the photovoltaic layer is The above-mentioned hole transport materials, electron transport materials, light-emitting materials, silicon, and CH3NH3PbI Perovskite crystals, such as those represented by 3, can be used. Furthermore, regarding the substrate and electrodes... Furthermore, the materials that can be used in the aforementioned light-emitting devices can also be utilized.

[0184] The configuration shown in this embodiment can be used in appropriate combination with other embodiments. Cut.

[0185] (Embodiment 2) In this embodiment, the light-emitting element has a configuration different from that shown in Embodiment 1. The light-emitting mechanism of the said light-emitting element will be explained below with reference to Figures 3 and 4. In Figures 3 and 4, parts having the same function as those shown in Figure 2(A) are indicated by the same symbols. A hatch pattern may be used, and the symbols may be omitted. Also, in areas with similar functions, Similar symbols may be used, and their detailed explanations may be omitted.

[0186] <Example of light-emitting element configuration 1> Figure 3(A) is a schematic cross-sectional view of the light-emitting element 250.

[0187] The light-emitting element 250 shown in Figure 3(A) has a pair of electrodes (electrode 101 and electrode 102) between them. , multiple light-emitting units (in Figure 3(A), light-emitting unit 106 and light-emitting unit 1 08) has. In addition, in the light-emitting element 250, the electrode 101 functions as an anode, and the electrode Assuming that 102 functions as the cathode, the following explanation will describe the configuration of the light-emitting element 250. It's fine the other way around too.

[0188] Furthermore, in the light-emitting element 250 shown in Figure 3(A), the light-emitting unit 106 and the light-emitting unit 108 and are stacked, and there is a charge between the light-emitting unit 106 and the light-emitting unit 108. A generation layer 115 is provided. Note that the light-emitting unit 106 and the light-emitting unit 108 have the same structure. It can be either a standard configuration or a different one.

[0189] Furthermore, the light-emitting element 250 has a light-emitting layer 120 and a light-emitting layer 170. In addition to the light-emitting layer 170, knit 106 also includes a hole injection layer 111, a hole transport layer 112, and an electron transport layer. It has a layer 113 and an electron injection layer 114. The light-emitting unit 108 also has a light-emitting layer 120 In addition, there is a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0190] The charge generation layer 115 is a hole transport material to which an acceptor substance, which is an electron acceptor, is added. Even with such a configuration, the electron transport material is combined with a donor substance that acts as an electron donor. This is also acceptable. Furthermore, both of these configurations may be stacked.

[0191] If the charge generation layer 115 contains a composite material of an organic compound and an acceptor substance, The composite material used is the same composite material that can be used in the hole injection layer 111 shown in Embodiment 1. That's all. As for organic compounds, aromatic amine compounds, carbazole compounds, aromatic carbon compounds Various compounds are used, such as hydrogen and polymer compounds (oligomers, dendrimers, polymers, etc.). It can exist. Furthermore, as an organic compound, its hole mobility is 1 × 10⁻⁶. -6 cm 2 / Vs It is preferable to use a material that meets the above criteria. However, a material that has higher hole transport than electron transport. In that case, other substances may be used. Composite materials of organic compounds and acceptor substances. Because the material has excellent carrier injection and carrier transport properties, it enables low-voltage and low-current operation. This can be achieved. Furthermore, the anode side of the light-emitting unit is in contact with the charge generation layer 115. In this case, the charge generation layer 115 also plays the role of a hole injection layer or hole transport layer of the light-emitting unit. Therefore, the light-emitting unit is configured without a hole injection layer or a hole transport layer. That is also acceptable. Alternatively, if the cathode side of the light-emitting unit is in contact with the charge generation layer 115. This means that the charge generation layer 115 also plays the role of an electron injection layer or electron transport layer of the light-emitting unit. Therefore, the light-emitting unit is configured without an electron injection layer or an electron transport layer. That's good too.

[0192] Furthermore, the charge generation layer 115 is a layer containing a composite material of an organic compound and an acceptor substance, and other It may be formed as a laminated structure by combining layers made of the following materials. For example, organic A layer containing a composite material of a compound and an acceptor substance, and one selected from among electron-donating substances. A layer containing the compound and a compound with high electron transport properties may be formed by combining them. A layer containing a composite material of an organic compound and an acceptor substance is combined with a layer containing a transparent conductive film. They may be formed together.

[0193] Furthermore, the charge generation layer 115 sandwiched between the light-emitting unit 106 and the light-emitting unit 108 is electric When a voltage is applied to electrode 101 and electrode 102, electrons are injected into one of the light-emitting units. Any method that injects holes into the other light-emitting unit is acceptable. For example, in Figure 3(A), When a voltage is applied such that the potential of electrode 101 is higher than the potential of electrode 102, The charge generation layer 115 injects electrons into the light-emitting unit 106 and holes into the light-emitting unit 108. Enter.

[0194] Furthermore, the charge generation layer 115 has light transmission to visible light (specifically) from the viewpoint of light extraction efficiency. It is preferable that the charge generation layer 115 has a visible light transmittance of 40% or more. Furthermore, the charge generation layer 115 has lower conductivity than the pair of electrodes (electrode 101 and electrode 102). It still works.

[0195] By forming the charge generation layer 115 using the materials described above, the light-emitting layer is stacked in the field This can suppress the rise in drive voltage during operation.

[0196] Furthermore, Figure 3(A) illustrates a light-emitting element having two light-emitting units. However, the same principle can also be applied to light-emitting devices that have three or more light-emitting units stacked on top of each other. As shown in the light-emitting element 250, multiple light-emitting units are placed between a pair of electrodes in a charge generation layer. By partitioning and arranging the elements, high-brightness light emission is possible while maintaining a low current density, and further This enables the creation of light-emitting elements with a long lifespan. Furthermore, it enables the creation of light-emitting elements with low power consumption. .

[0197] In addition, in each of the above configurations, the ges used in the light-emitting unit 106 and the light-emitting unit 108 The luminescent colors exhibited by the materials may be the same or different. Guest material having the function of emitting light of the same color in both T 106 and light-emitting unit 108 When this is present, the light-emitting element 250 becomes a light-emitting element that exhibits high luminous brightness with a low current value, which is preferable. Furthermore, the light-emitting unit 106 and the light-emitting unit 108 emit light of different colors from each other. When a guest material has the function of emitting light, the light-emitting element 250 exhibits multicolor emission. This is preferable. In this case, either one or both of the light-emitting layer 120 and the light-emitting layer 170 are preferable. By using multiple light-emitting materials with different emission wavelengths, the light-emitting element 250 exhibits light emission Since the spectrum is the result of light synthesized from emission with different emission peaks, at least two This results in an emission spectrum with a maximum value of [value].

[0198] The above configuration is also suitable for obtaining white light emission. Light emission from light emission layer 120 and light emission layer 170 By making them complementary colors to each other, white light emission can be obtained. In particular, color rendering Guest material to produce high white light emission, or light emission that has at least red, green, and blue light It is preferable to select a specific type of material.

[0199] Furthermore, in the case of a light-emitting element with three or more light-emitting units stacked, each light-emitting unit is used The luminescence colors exhibited by the guest materials may be the same or different. When there are multiple light-emitting units, the light-emitting colors emitted by these multiple light-emitting units are: Compared to other colors, high luminescence can be obtained with a lower current value. The material can be suitably used to adjust the emission color. In particular, it can be used when the luminous efficiency is different and different This is suitable when using guest materials that exhibit luminescence. For example, when using a three-layer luminescent unit. In this case, two layers of light-emitting units having fluorescent materials of the same color are used, and a different light-emitting color is used for the fluorescent material. By using a light-emitting unit with a phosphorescent material as a single layer, the intensity of fluorescence emission and phosphorescence emission can be increased. The degree can be adjusted. In other words, the intensity of the emitted color can be adjusted by changing the number of light-emitting units. It is Noh.

[0200] In the case of a light-emitting element having two layers of fluorescent emission units and one layer of phosphorescent emission units, blue It contains two layers of light-emitting units containing colored fluorescent materials and one layer of light-emitting units containing yellow phosphorescent material. A light-emitting element or a light-emitting unit containing a blue fluorescent material is provided in two layers, along with a red phosphorescent material and a green phosphorescent material. A light-emitting element having one light-emitting layer unit, and a light-emitting element having two layers of light-emitting units containing blue fluorescent material and red A light-emitting element having one light-emitting layer unit containing phosphorescent material, yellow phosphorescent material, and green phosphorescent material, This is preferable because it allows for efficient emission of white light.

[0201] Furthermore, at least one of the light-emitting layer 120 or the light-emitting layer 170 is further divided into layers, Each divided layer may contain a different light-emitting material. That is, light-emitting layer 12 0, or at least one of the light-emitting layers 170 may be composed of two or more layers. For example, a first light-emitting layer and a second light-emitting layer are stacked in order from the hole transport layer side to form a light-emitting layer. In this case, a material having hole transport properties is used as the host material for the first light-emitting layer, and the second light-emitting layer One configuration involves using an electron-transporting material as the host material. In this case, the first The light-emitting material of the light-emitting layer and the second light-emitting layer may be the same material or different materials. Even if materials have the function of emitting light of the same color, they may have the function of emitting light of different colors. It may also be a material having the function of exhibiting light emission of different colors from each other. This configuration allows for the production of highly color-rendering white light consisting of three primary colors or four or more emission colors. It is also possible.

[0202] Furthermore, of the multiple units, at least one unit has the configuration shown in Embodiment 1. By applying this technology, we can provide a light-emitting element with good light extraction efficiency and reduced drive voltage. It can be provided.

[0203] Furthermore, as shown in Figure 3(B), the light-emitting layer 120 of the light-emitting unit 108 is a guest The device comprises material 121 and host material 122. The guest material 121 is a fluorescent material. The following explains this.

[0204] ≪Light-emitting mechanism of light-emitting layer 120≫ The light-emitting mechanism of the light-emitting layer 120 will be explained below.

[0205] A pair of electrodes (electrode 101 and electrode 102) or electricity injected from the charge generation layer 115 Excitons are generated when electrons and holes recombine in the light-emitting layer 120. Since host material 122 is present in large quantities compared to material 121, the generation of excitons will An excited state is formed in the host material 122. Note that excitons are carriers (electrons and holes). ) It refers to a pair.

[0206] If the excited state of the formed host material 122 is a singlet excited state, then the host material 12 Singlet excitation energy is transferred from the S1 level of material 2 to the S1 level of guest material 121. Then, a singlet excited state is formed in guest material 121.

[0207] Since guest material 121 is a fluorescent material, the singlet excited state in guest material 121 Once formed, the guest material 121 rapidly emits light. At this time, to obtain high luminescence efficiency... Therefore, it is preferable that the fluorescence quantum yield of guest material 121 is high. The same applies in case 1, when carriers recombine and the resulting excited state is a singlet excited state. That is the case.

[0208] Next, when a triplet excited state of the host material 122 is formed by carrier recombination... This will be explained. The energy levels of the host material 122 and guest material 121 in this case. The correlation of the positions is shown in Figure 3(C). The notation and symbols in Figure 3(C) are as follows: Furthermore, the T1 level of the host material 122 is lower than the T1 level of the guest material 121. Since this is preferable, Figure 3(C) illustrates this case, but the T1 level of the host material 122 This may be higher than the T1 level of guest material 121.

[0209] • Guest(121): Guest material 121 (fluorescent material) • Host(122): Host material 122 ·S FG : S1 level of guest material 121 (fluorescent material) ·T FG :T1 level of guest material 121 (fluorescent material) ·S FH : S1 level of host material 122 ·T FH :T1 level of host material 122

[0210] As shown in Figure 3(C), triplet-triplet annihilation (TTA: Triplet-Tripl Triplets generated by carrier recombination (et Annihilation) Excitons interact with each other, exchanging excitation energy and spin angular momentum. By doing so, the S1 level of the host material 122 (S FH ) has the energy A reaction occurs that converts to a singlet exciton (see Figure 3(C) TTA). Host material 122 The singlet excitation energy of is S FH Therefore, guest material 121 has lower energy. S1 level (S FG Energy transfer occurs to (see Route E1 in Figure 3(C)), and the guest A singlet excited state is formed in material 121, and the guest material 121 emits light.

[0211] Furthermore, if the density of triplet excitons in the light-emitting layer 120 is sufficiently high (for example, 1 × 10⁻¹⁰ 12 cm -3 (The above) ignores the deactivation of a single triplet exciton and considers two closely spaced triplet excitations. We can consider only the child's response.

[0212] Furthermore, when carriers recombine in guest material 121 and a triplet excited state is formed... The triplet excited state of guest material 121 is thermally deactivated, making it difficult to utilize for luminescence. However, the T1 level (T) of the host material 122 FH ) is a T1 standard of guest material 121 Place(T FG If it is lower than ), the triplet excitation energy of guest material 121 is, 21 T1 levels (T FG ) from the T1 level of host material 122 (T FH Energy transfer to ) It is possible to do this (see Figure 3(C) Route E2), and it is then used for TTA.

[0213] In other words, the host material 122 has a triplet excitation energy, and a singlet excitation energy is obtained by TTA. It is preferable that it has the function of converting into energy. By doing so, the light generated in the light-emitting layer 120 A portion of the triplet excitation energy is obtained by singlet excitation energy by TTA in the host material 122. By converting it into energy and transferring the singlet excitation energy to the guest material 121, fluorescence It becomes possible to extract it as luminescence. To do this, the S1 level (S) of the host material 122 is needed. FH ) is the S1 level (S FG It is preferable that it is higher than ) Also, phos T1 level of material 122 (T FH ) is the T1 level (T FG ) lower It is preferable.

[0214] In particular, the T1 level of guest material 121 (T FG ) is the T1 level of the host material 122 ( T FH If it is lower than ), the weight ratio of host material 122 to guest material 121 is It is preferable that the weight ratio of the guest material 121 is low. Specifically, the host material 122 is 1 and The weight ratio of guest material 121 in that case is preferably greater than 0 and 0.05 or less. This reduces the probability of carrier recombination in guest material 121. Furthermore, the T1 level of host material 122 (T FH ) from guest material 121 T1 level (T FG ) This can reduce the probability of energy transfer occurring.

[0215] The host material 122 may be composed of a single compound, or it may be composed of multiple compounds. It's fine if it's done.

[0216] Furthermore, the light-emitting unit 106 and the light-emitting unit 108 have guest materials with different light-emitting colors. In this case, the emission from the light-emitting layer 120 is on the shorter wavelength side than the emission from the light-emitting layer 170. It is preferable to have a configuration that has a -. A material having a high triplet excitation energy level The light-emitting element used tends to degrade in brightness quickly. Therefore, a light-emitting layer that exhibits short wavelength emission is used. By using TA, it is possible to provide light-emitting elements with minimal brightness degradation.

[0217] <Example of light-emitting element configuration 2> Figure 4(A) is a schematic cross-sectional view of the light-emitting element 252.

[0218] The light-emitting element 252 shown in Figure 4(A) has a pair of electrodes, similar to the light-emitting element 250 shown earlier. Between electrodes 101 and 102, there are multiple light-emitting units (in Figure 4(A), It has a light unit 106 and a light-emitting unit 110). At least one light-emitting unit is , it has a similar configuration to the EL layer 100. Furthermore, the light-emitting unit 106 and light-emitting unit 110 The configuration can be the same or different.

[0219] Furthermore, in the light-emitting element 252 shown in Figure 4(A), the light-emitting unit 106 and the light-emitting unit 110 and are stacked, and between the light-emitting unit 106 and the light-emitting unit 110 there is an electric current A raw layer 115 is provided. For example, it is preferable to use an EL layer 100 in the light-emitting unit 106. It's nice.

[0220] Furthermore, the light-emitting element 252 has a light-emitting layer 140 and a light-emitting layer 170. In addition to the light-emitting layer 170, knit 106 also includes a hole injection layer 111, a hole transport layer 112, and an electron transport layer. It has a layer 113 and an electron injection layer 114. The light-emitting unit 110 also has a light-emitting layer 140 In addition, there is a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0221] Furthermore, of the multiple units, at least one unit is as shown in Embodiment 1. By applying this configuration, a light-emitting element with good light extraction efficiency and reduced drive voltage is obtained. It can be provided.

[0222] The light-emitting layer 140 of the light-emitting unit 110 is made of guest material 1, as shown in Figure 4(B). It comprises 41 and a host material 142. Furthermore, the host material 142 is an organic compound 142_ It comprises 1 and organic compound 142_2. Note that the guest material 14 of the light-emitting layer 140 1 is a phosphorescent material, which will be explained below.

[0223] ≪Light-emitting mechanism of light-emitting layer 140≫ Next, the light-emitting mechanism of the light-emitting layer 140 will be explained below.

[0224] The organic compound 142_1 and organic compound 142_2 present in the light-emitting layer 140 form an excited complex. It forms.

[0225] The combination of organic compound 142_1 and organic compound 142_2 may be any combination that can form an exciplex with each other, but it is more preferable that one is a compound having hole transporting property and the other is a compound having electron transporting property.

[0226] The correlation of the energy levels among organic compound 142_1, organic compound 142_2, and guest material 141 in the light-emitting layer 140 is shown in Fig. 4(C). Note that the notations and symbols in Fig. 4(C) are as follows.

[0227] ·Guest(141): Guest material 141 (phosphorescent material) ·Host(142_1): Organic compound 142_1 (host material) ·Host(142_2): Organic compound 142_2 (host material) ·T PG : T1 level of guest material 141 (phosphorescent material) ·S PH1 : S1 level of organic compound 142_1 (host material) ·T PH1 : T1 level of organic compound 142_1 (host material) ·S PH2 : S1 level of organic compound 142_2 (host material) ·T PH2 : T1 level of organic compound 142_2 (host material) ·S PE : S1 level of exciplex ·T PE : T1 level of exciplex

[0228] Organic compound 142_1 and organic compound 142_2 form an exciplex, and the S 1 level (S PE ) and T1 level (T PE ) of the exciplex become adjacent energies to each other (see Route E3 in Fig. 4(C) ).

[0229] Organic compound 142_1 and organic compound 142_2 quickly form an exciplex by one receiving holes and the other receiving electrons. Alternatively, when one is in an excited state, it quickly interacts with the other to form an exciplex. Therefore, most of the excitons in the light-emitting layer 140 exist as exciplexes. The excitation energy levels (S or T ) of the exciplex are lower than the S1 levels (S and S PE also is T PE ) of the host materials (organic compound 142_1 and organic compound 1 42_2) that form the exciplex, so it is possible to form an excited state of the host material 142 with lower excitation energy. As a result, the driving voltage of the light-emitting element can be reduced. PH1 and S PH2 ) of the host materials (organic compound 142_1 and organic compound 1 can be formed with lower excitation energy, making it possible to reduce the driving voltage of the light-emitting element. Then, by transferring the energies of both the S

[0230] and T PE of the exciplex to the T1 level of the guest material 141 (phosphorescent material PE ), light emission can be obtained (see Routes E4 and E5 in Fig. 4(C)). Note that the T1 level (T

[0231] ) of the exciplex is preferably higher than the T1 level (T PE ) of the guest material 141. By doing so, the singlet excitation energy and triplet excitation energy of the generated exciplex can be transferred from the S1 level (S PG ) and T1 level (T ) of the exciplex to the T1 level (T ​​​​​​​​​​​​​​​​) forms an excited complex with each organic compound (organic compound 14 T1 level of 2_1 and organic compound 142_2) (T PH1 and T PH2 ) is equivalent to, Smaller is preferable. This allows each organic compound (organic compound 142_1 and organic Compound 142_2) makes it less likely for the triplet excitation energy of the excited complex to quench. This allows for efficient energy transfer from the excited complex to the guest material 141.

[0233] Furthermore, organic compound 142_1 and organic compound 142_2 efficiently form an excited complex. In order to do so, the HOMO level of one of the organic compounds 142_1 and 142_2 must The fact that one LUMO level is higher than the other HOMO level, and one LUMO level is higher than the other LUMO level. Preferred. For example, if organic compound 142_1 has hole transport properties, and organic compound 142_2 If it has electron transport properties, the HOMO level of organic compound 142_1 is the same as that of organic compound 142_2 It is preferable that the LUMO level is higher than the HOMO level, and the LUMO level of organic compound 142_1 is organically modified. It is preferable that the LUMO level is higher than that of compound 142_2. Alternatively, organic compound 142_ If 2 has hole transport properties and organic compound 142_1 has electron transport properties, then organic compound 1 It is preferable that the HOMO level of 42_2 is higher than that of organic compound 142_1. The LUMO level of organic compound 142_2 is higher than that of organic compound 142_1. This is preferable. Specifically, the HOMO level of organic compound 142_1 and organic compound 142 The energy difference with the HOMO level of _2 is preferably 0.05 eV or more, and more preferably The voltage is 0.1 eV or higher, and more preferably 0.2 eV or higher. The energy difference between the LUMO level of substance 142_1 and the LUMO level of organic compound 142_2 is Preferably 0.05 eV or higher, more preferably 0.1 eV or higher, and even more preferably The voltage is 0.2 eV or higher.

[0234] Furthermore, the combination of organic compound 142_1 and organic compound 142_2 exhibits hole transport properties. In the case of a combination of a compound that possesses electron transport properties and a compound that has electron transport properties, the mixing ratio of the two compounds... This makes it possible to easily control the carrier balance. Specifically, it has hole transport properties. Compounds: Compounds with electron transport properties = preferably in the range of 1:9 to 9:1 (by weight). Furthermore, having this configuration makes it easy to control the career balance. Furthermore, the carrier recombination region can be easily controlled.

[0235] By configuring the light-emitting layer 140 as described above, the guest material 141 (phosphorescent material) of the light-emitting layer 140 This makes it possible to efficiently obtain light emission from ).

[0236] Furthermore, the processes of routes E3 to E5 shown above are referred to as ExTET(Ex in this specification, etc.). It is sometimes referred to as ciplex-triplet energy transfer. In other words, the light-emitting layer 140 provides the excitation energy from the excited complex to the guest material 141. There is a provision. Note that in this case, it is not necessarily T PE From S PE The reverse interterm crossing efficiency needs to be high. No, S PE Since a high emission quantum yield is not required, a wide range of materials can be selected. It becomes possible.

[0237] Furthermore, the emission from the light-emitting layer 170 has a shorter wavelength peak than the emission from the light-emitting layer 140. It is preferable to have a configuration that has a luminescent element. The child tends to experience rapid brightness degradation. Therefore, by using fluorescence emission for short-wavelength emission, This makes it possible to provide a light-emitting element with minimal brightness degradation.

[0238] <Examples of materials that can be used for the light-emitting layer> Next, regarding materials that can be used for the light-emitting layer 120, light-emitting layer 140, and light-emitting layer 170... I will now explain.

[0239] <<Materials that can be used for the light-emitting layer 120>> In the light-emitting layer 120, the host material 122 is the most abundant by weight, and the guest material 121 The (fluorescent material) is dispersed in the host material 122. The S1 level of the host material 122 is The T1 level of host material 122 is higher than the S1 level of host material 121 (fluorescent material), and the G It is preferable that the level is lower than the T1 level of the fluorescent material 121.

[0240] In the light-emitting layer 120, there are no particular limitations on the guest material 121, but anthracene is also acceptable. Derivatives, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives, Lylene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxazine Derivatives, phenothiazine derivatives, etc. are preferred, and the fluorescent compounds shown in Embodiment 1 are preferred. It can be used appropriately.

[0241] Furthermore, in the light-emitting layer 120, the materials that can be used for the host material 122 are: There are no particular limitations, but for example, tris(8-quinolinolato)aluminum(III) (abbreviation) :Alq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) Abbreviation: BeBq2), bis(2-methyl-8-quinolinolate)(4-phenylphenolate ) Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (Abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolate]zinc(II) Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) Metal complexes such as (abbreviated as ZnBTZ), 2-(4-biphenylyl)-5-(4-tert- Butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5 -(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]ben Zen (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-te rt-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2' -(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimidazo Vasophenanthroline (abbreviation: TPBI), Vasophenanthroline (abbreviation: BPhen), Vasocuproline (Abbreviation: BCP), 9-[4-(5-phenyl-1,3,4-oxadiazole-2- Heterocyclic compounds such as yl(phenyl)-9H-carbazole (abbreviation: CO11), 4,4 '-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) (α-NPD), 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) Examples include aromatic amine compounds such as BSPB. Also, anthracene derivatives, ferrous compounds, etc. Nanthrene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g,p]chrysene derivatives Examples include condensed polycyclic aromatic compounds such as 9,10-diphenylanthracene (Abbreviation: DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-Anth) Tolyl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-( 10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), 4-(9 H-carbazole-9-yl)-4'-(10-phenyl-9-antryl)triphenyl Luamine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9 -Anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), N ,9-diphenyl-N-{4-[4-(10-phenyl-9-antryl)phenyl]f phenyl-9H-carbazole-3-amine (abbreviation: PCAPBA), N,9-diphenyl ru-N-(9,10-diphenyl-2-anthryl)-9H-carbazole-3-amine (Abbreviation: 2PCAPA), 6,12-dimethoxy-5,11-diphenylchrysene, N, N,N',N',N'',N'',N''',N'''-Octaphenyldibenzo[g, p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(1 O-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-antryl)phenyl]-9H -Carbazole (abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl )Anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation :DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation) :t-BuDNA), 9,9'-biantril (abbreviation: BANT), 9,9'-(still Ben-3,3'-diphenylenanthren (abbreviation: DPNS), 9,9'-(Stilbe n-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), 3,3',3''-( Examples include benzene-1,3,5-triyl)tripylene (abbreviation: TPB3). It is possible. Also, from among these and known substances, the energy gap of the above guest material 121 If you select and use one or more materials that have a larger energy gap than P good.

[0242] The light-emitting layer 120 can also be composed of two or more layers. For example, the first When the first light-emitting layer and the second light-emitting layer are stacked in order from the hole transport layer side to form the light-emitting layer 120, A material having hole transport properties is used as the host material for the first light-emitting layer, and the host material for the second light-emitting layer One such configuration involves using materials that possess electron-transporting properties.

[0243] Furthermore, in the light-emitting layer 120, the host material 122 is composed of a certain compound. It is also fine if it is composed of multiple compounds. Alternatively, in the light-emitting layer 120, It may also contain materials other than stock material 122 and guest material 121.

[0244] <<Materials that can be used for the light-emitting layer 140>> In the light-emitting layer 140, the host material 142 is the most abundant by weight, and the guest material 141 The (phosphorescent material) is dispersed in the host material 142. Host material 142 of the light-emitting layer 140 ( The T1 level of organic compound 142_1 and organic compound 142_2 is the same as the T level of guest material 141. It is preferable that the level be higher than level 1.

[0245] Organic compound 142_1 includes zinc and aluminum-based metal complexes, as well as oxadiazo Diazepam derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, diazepam Dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidin phenanthroline derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives Examples include conductors. Other examples include aromatic amines and carbazole derivatives. Specifically, using the electron-transporting material and hole-transporting material shown in Embodiment 1, It is possible.

[0246] Organic compound 142_2 is a combination that can form an excited complex with organic compound 142_1. A combination is preferred. Specifically, the electron transport material and hole transport material shown in Embodiment 1. A material can be used. In this case, organic compound 142_1 and organic compound 142_2 The emission peak of the excited complex formed is the triplet MLCT of guest material 141 (phosphorescent material) The absorption band of the Metal to Light Charge Transfer transition, Specifically, organic compound 142_1 and organic compound 142_1 are positioned so as to overlap with the absorption band on the longest wavelength side. It is preferable to select material 142_2 and guest material 141 (phosphorescent material). This allows for the creation of a light-emitting element with dramatically improved luminescence efficiency. However, if the phosphorescent material is replaced... Furthermore, when using thermally activated delayed fluorescence materials, the absorption band on the longest wavelength side is singlet absorption. It is preferable that it be a cascading area.

[0247] Guest material 141 (phosphorescent material) includes iridium, rhodium, or platinum-based organic materials. Examples include metal complexes, or metal complexes in particular, organoiridium complexes, such as iridium Orthometallic complexes are preferred. 4H-triazole is a suitable ligand for orthometallation. Ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidines Examples include ligands, pyrazine ligands, or isoquinoline ligands. Examples include platinum complexes having porphyrin ligands. Specifically, in the embodiment... The material exemplified as guest material 132 shown in 1 can be used.

[0248] The light-emitting material included in the light-emitting layer 140 is capable of converting triplet excitation energy into light emission. Any material will do. A material that can convert the triplet excitation energy into light emission is a phosphorescent material. In addition, thermally activated delayed fluorescence materials can be mentioned. Therefore, the part that was described as phosphorescent material is relevant. Therefore, it is acceptable to interpret this as a thermally activated delayed fluorescence material.

[0249] Furthermore, materials exhibiting thermally activated delayed fluorescence can be subjected to reverse intersystem crossing from a triplet excited state. It may be a material capable of generating a multiplet excited state, or an excited complex (excyplex, also It may be composed of multiple materials that form an Exciplex (also known as an Exciplex).

[0250] When a thermally activated delayed fluorescence material is composed of one type of material, specifically, in the embodiment The thermally activated delayed fluorescence material shown in 1 can be used.

[0251] Furthermore, when using a thermally activated delayed fluorescence material as a host material, two types of excitation complexes are formed. It is preferable to use a combination of compounds of the same type. In this case, the excitation complex shown above is formed The combinations that make up the combination are compounds that readily accept electrons and compounds that readily accept holes. It is particularly preferable to use [this].

[0252] <<Materials that can be used for the light-emitting layer 170>> Materials that can be used for the light-emitting layer 170 include those used for the light-emitting layer shown in Embodiment 1. By using materials that can do this, it is possible to fabricate light-emitting elements with high luminescence efficiency. It is possible.

[0253] Furthermore, the emission color of the light-emitting material contained in the light-emitting layer 120, light-emitting layer 140, and light-emitting layer 170 There are no limitations; they can be the same or different. The light emitted from each is mixed. Since it is extracted outside the element, for example, if the light emitted by both is complementary to each other, the light-emitting element The child can emit white light. Considering the reliability of the light-emitting element, the light-emitting layer 120 is included The emission peak wavelength of the light-emitting material is shorter than that of the light-emitting material contained in the light-emitting layer 170. This is preferable.

[0254] Furthermore, the light-emitting unit 106, light-emitting unit 108, light-emitting unit 110, and charge generation Layer 115 can be produced using methods such as vapor deposition (including vacuum deposition), inkjet printing, coating, and gravure printing. It can be formed by the following method.

[0255] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there.

[0256] (Embodiment 3) Figure 5(A) is a top view showing the light-emitting device, and Figure 5(B) is Figure 5(A) with AB and CD. This is a cross-sectional view. This light-emitting device controls the light emission of the light-emitting element, as indicated by the dotted line. The indicated drive circuit section (source side drive circuit) 601, pixel section 602, drive circuit section (gate side It includes a drive circuit (603). Also, 604 is a sealing substrate, 625 is a desiccant, and 605 is a shi It is a sealing material, and the inside, surrounded by the sealing material 605, is a space 607.

[0257] The routing wiring 608 is input to the source-side drive circuit 601 and the gate-side 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 Even if a Printed Wiring Board (PWB) is attached Good. The light-emitting device in this specification includes not only the light-emitting device body but also an FPC or This includes the state in which the PWB is installed.

[0258] Next, the cross-sectional structure of the above-mentioned light-emitting device will be explained using Figure 5(B). On the element substrate 610 A drive circuit section and a pixel section are formed here, but here, the source-side drive is the drive circuit section. The circuit 601 and one pixel in the pixel section 602 are shown.

[0259] The source-side drive circuit 601 uses an n-channel TFT623 and a p-channel TFT624. A CMOS circuit is formed by combining these. In addition, the drive circuit can be various CMOS circuits, P It may also be formed using MOS circuits or NMOS circuits. In this embodiment, the drive circuit is also located on the substrate. This shows a driver integrated into the board, but it is not necessarily required, and the drive circuit can be placed on the board. It is not necessary, and it can also be formed externally.

[0260] Furthermore, the pixel section 602 consists of a switching TFT 611 and a current control TFT 612 and its drain It is formed by a pixel including a first electrode 613 electrically connected to the input. An insulator 614 is formed to cover the end of the electrode 613. The insulator 614 is positive It can be formed by using a photosensitive resin film of a mold.

[0261] Furthermore, in order to improve the coverage of the film formed on the insulator 614, the insulator 614 A surface having curvature is formed at the upper or lower end. For example, the insulating material 614 When using photosensitive acrylic as the material, the curved surface is made only at the upper end of the insulator 614. The radius of curvature of the curved surface is preferably 0.2 μm or more and 0.3 μm or less. As the border material 614, either a negative-type or positive-type photosensitive material may be used. It is possible.

[0262] An EL layer 616 and a second electrode 617 are formed on the first electrode 613, respectively. Here, the material used for the first electrode 613 which functions as an anode is a material with a work function of It is desirable to use large materials. For example, ITO film or silicon-containing indigo Indium oxide film containing 2 wt% to 20 wt% zinc oxide, nitriding In addition to single-layer films such as titanium films, chromium films, tungsten films, Zn films, and Pt films, titanium nitride films are also available. Lamination of a film mainly composed of aluminum, and a titanium nitride film and a film mainly composed of aluminum A three-layer structure consisting of a film and a titanium nitride film can be used. Note that in a laminated structure, wiring... It has low resistance as an anode, provides good ohmic contact, and can also function as an anode. It is possible.

[0263] 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 material constituting the EL layer 616 is a low molecular weight compound It may be a substance or a polymer compound (including oligomers and dendrimers).

[0264] Furthermore, the material used for the second electrode 617, which is formed on the EL layer 616 and functions as a cathode. Examples include materials with a low work function (Al, Mg, Li, Ca, or alloys and compounds thereof) It is preferable to use materials such as MgAg, MgIn, AlLi, etc. If the generated light passes through the second electrode 617, the film thickness of the second electrode 617 is reduced. A thin metal film and a transparent conductive film (ITO, containing 2 wt% to 20 wt% zinc oxide) Lamination with indium oxide, silicon-containing indium tin oxide, zinc oxide (ZnO), etc. It is best to use this.

[0265] Furthermore, the first electrode 613, the EL layer 616, and the second electrode 617 form the light-emitting element 618. It is done. The light-emitting element 618 is a light-emitting element having the configuration of Embodiment 1 and Embodiment 2. It is preferable that this is the case. Note that the pixel portion is made up of multiple light-emitting elements, but in this embodiment In the embodiment, the light-emitting device has the configuration described in Embodiment 1 and Embodiment 2. The device may include both an element and a light-emitting element having other components.

[0266] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, A light-emitting element 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 618. Furthermore, the space 607 is filled with a filler material. In addition to cases where an inert gas (such as nitrogen or argon) is filled, resin or desiccant or the same In some cases, both may be used for filling.

[0267] 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.

[0268] As described above, a light-emitting device using the light-emitting element described in Embodiment 1 and Embodiment 2. You can obtain this.

[0269] <Example of Light-Emitting Device Configuration 1> Figure 6 shows an example of a light-emitting device, in which a light-emitting element that emits white light is formed, and a colored layer (colorf An example of a light-emitting device with a filter is shown.

[0270] Figure 6(A) shows the substrate 1001, the underlayer insulating film 1002, the gate insulating film 1003, and the gate electrode. 1006, 1007, 1008, first interlayer insulating film 1020, second interlayer insulating film 1021 , peripheral portion 1042, pixel portion 1040, drive circuit portion 1041, first electrode 102 of the light-emitting element 4W, 1024R, 1024G, 1024B, partition 1026, EL layer 1028, light-emitting element The second electrode 1029, the sealing substrate 1031, the sealing material 1032, etc., are shown in the diagram.

[0271] Furthermore, Figures 6(A) and 6(B) show the colored layers (red colored layer 1034R, green colored layer 10 34G, a blue colored layer (1034B) is provided on a transparent substrate 1033. Also, a black layer ( A black matrix (1035) may be further provided. A colored layer and a black layer are provided. The transparent substrate 1033 is aligned and fixed to the substrate 1001. Note that the colored layer and black The color layer is covered with an overcoat layer 1036. Also, in Figure 6(A), light A light-emitting layer that emits light to the outside without passing through the colored layer, and a light-emitting layer that emits light to the outside by passing through the colored layer of each color. There are layers, and light that does not pass through the colored layer is white, while light that passes through the colored layer is red, blue, and green. Furthermore, images can be represented using four-color pixels.

[0272] Figure 6(B) shows the red colored layer 1034R, the green colored layer 1034G, and the blue colored layer 103 An example is shown in which 4B is formed between the gate insulating film 1003 and the first interlayer insulating film 1020. As shown in Figure 6(B), the colored layer may be provided between the substrate 1001 and the sealing substrate 1031. stomach.

[0273] Furthermore, in the light-emitting device described above, light is taken to the substrate 1001 on which the TFT 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).

[0274] <Example of Light-Emitting Device Configuration 2> Figure 7 shows a cross-sectional view of a top-emission type light-emitting device. In this case, the substrate 1001 emits light. A non-transparent substrate can be used. A connecting electrode is made to connect the TFT and the anode of the light-emitting element. Until manufacturing, it is formed in the same way as a bottom-emission type light-emitting device. After that, the third interlayer An insulating film 1037 is formed covering the electrode 1022. This insulating film plays a role in planarization. It is also acceptable. The third interlayer insulating film 1037 is made of the same material as the second interlayer insulating film 1021, as well as other materials. It can be formed using a variety of materials.

[0275] The first lower electrodes 1025W, 1025R, 1025G, and 1025B of the light-emitting element are located here. It is designated as the anode, but it can also be the cathode. Also, a top-emission type generator as shown in Figure 7. In the case of an optical device, the lower electrodes 1025W, 1025R, 1025G, and 1025B are reflected. It is preferable to use an electrode. The second electrode 1029 has the function of reflecting light and transmitting light. It is preferable that it has the function of having the second electrode 1029 and the lower electrodes 1025W, 102 A microcavity structure is applied between 5R, 1025G, and 1025B to capture light of a specific wavelength. It is preferable that it has an amplification function. The configuration of the EL layer 1028 was described in Embodiment 2. The device structure is designed to produce white light emission.

[0276] In Figures 6(A), 6(B), and 7, the configuration of the EL layer that produces white light emission is as follows: This can be achieved by using multiple light-emitting layers or multiple light-emitting units. Furthermore, the configurations for obtaining white light emission are not limited to these.

[0277] In the top emission structure shown in Figure 7, the colored layer (red colored layer 1034R, green colored layer) The sealing is performed using a sealing substrate 1031 having layer 1034G and a blue colored layer 1034B. Yes, it is possible. The encapsulating substrate 1031 has a black layer (black matrix) positioned between the pixels. A colored layer (red colored layer 1034R, green colored layer 1) may be provided. 034G, the blue colored layer (1034B), and the black layer (black matrix) are overcoated. It may be covered with a layer. The sealing substrate 1031 is a light-transmitting substrate. .

[0278] 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 three colors: red, green, and blue. Alternatively, four colors may be used: red, green, blue, and yellow. Full-color display is permitted.

[0279] As described above, a light-emitting device using the light-emitting element described in Embodiment 1 and Embodiment 2. You can obtain this.

[0280] Furthermore, this embodiment can be appropriately combined with other embodiments.

[0281] (Embodiment 4) This embodiment describes an electronic device according to one aspect of the present invention.

[0282] One aspect of the present invention is a light-emitting element using an organic EL, and therefore has a flat surface and good luminous efficiency. This enables the manufacture of highly reliable electronic devices. Furthermore, according to one aspect of the present invention, a curved surface and light emission can be produced. Highly efficient and reliable electronic devices can be manufactured. Furthermore, according to one aspect of the present invention, flexible It is possible to manufacture highly reliable electronic devices that possess properties and have good luminous efficiency.

[0283] Examples of electronic devices include television equipment, desktop or notebook computers, etc. Sony computers, monitors for computers, digital cameras, digital video cameras Cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, audio playback devices. Examples include devices and large game machines such as pachinko machines.

[0284] Furthermore, a light-emitting device according to one aspect of the present invention can achieve high visibility regardless of the intensity of ambient light. Yes, it is possible. Therefore, portable electronic devices, wearable electronic devices, and electric devices are available. It can be suitably used in devices such as child book terminals.

[0285] The portable information terminal 900 shown in Figures 8(A) and (B) consists of a housing 901, a housing 902, and a display unit 90 3, and the hinge portion 905, etc.

[0286] The housing 901 and housing 902 are connected by a hinge portion 905. The portable information terminal 900 is It can be unfolded from its folded state (Figure 8(A)) as shown in Figure 8(B). This makes it highly portable when carrying it around, and when in use, the large display area provides excellent visibility. Excellent visibility.

[0287] The portable information terminal 900 has two housings, 901 and 902, connected by a hinge 905. A flexible display unit 903 is provided.

[0288] A light-emitting device manufactured using one aspect of the present invention can be used in the display unit 903. This allows for the production of mobile information terminals with a high yield.

[0289] The display unit 903 displays at least one of the following: document information, still images, and moving images. This is possible. When displaying document information on the display unit, the portable information terminal 900 can be used as an e-book terminal. It can be used in this way.

[0290] When the portable information terminal 900 is unfolded, the display unit 903 is held in a significantly curved shape. For example, a curved shape with a radius of curvature of 1 mm to 50 mm, preferably 5 mm to 30 mm. The display unit 903 is held, including a portion of it. A portion of the display unit 903 is separated from the housing 901. By arranging pixels continuously across 902, a curved surface can be displayed.

[0291] The display unit 903 functions as a touch panel and can be operated with a finger or stylus. can.

[0292] The display unit 903 is preferably composed of a single flexible display. This allows for uninterrupted, continuous display between casing 901 and casing 902. Yes, it is possible. Furthermore, the configuration includes a display in both the chassis 901 and chassis 902. You may do so.

[0293] The hinge portion 905 is located between the housing 901 and the housing 902 when the portable information terminal 900 is unfolded. It is preferable to have a locking mechanism to prevent the angle from becoming larger than a predetermined angle. For example, the angle at which it locks (and cannot be opened further) is between 90 and 180 degrees. It is preferable that there be a certain angle, typically 90 degrees, 120 degrees, 135 degrees, 150 degrees, or 17 degrees. It can be set to 5 degrees, for example. This improves the convenience, safety, and of the mobile information terminal 900. This can increase reliability.

[0294] If the hinge portion 905 has a locking mechanism, then the display portion 903 will not be subjected to excessive force, This prevents damage to the display unit 903. Therefore, a highly reliable portable information terminal can be used. It can be achieved.

[0295] Enclosures 901 and 902 include a power button, operation buttons, an external connection port, a speaker, and a m You must have an orgasm or something similar.

[0296] Either the housing 901 or the housing 902 is provided with a wireless communication module. Internet, LAN (Local Area Network), Wi-Fi (registered trademark) It is possible to send and receive data via computer networks such as ).

[0297] The portable information terminal 910 shown in Figure 8(C) consists of a housing 911, a display unit 912, and operation buttons 913. It also has an external connection port 914, a speaker 915, a microphone 916, a camera 917, etc.

[0298] A light-emitting device manufactured using one aspect of the present invention can be used in the display unit 912. This allows for the production of mobile information terminals with a high yield.

[0299] The personal information terminal 910 is equipped with a touch sensor on the display unit 912. All operations, such as typing characters, are performed by touching the display unit 912 with a finger or stylus. It is possible to do so.

[0300] Furthermore, the operation button 913 can be used to turn the power ON or OFF, and to display information on the display unit 912. You can switch the type of image displayed. For example, from the email composition screen, You can switch to the menu screen.

[0301] Furthermore, the mobile information terminal 910 contains a detection device such as a gyro sensor or an accelerometer. By providing this, the orientation of the mobile information terminal 910 (vertical or horizontal) is determined, and the screen of the display unit 912 is changed. The display orientation can be switched automatically. Also, the screen display orientation can be switched. Touching the display unit 912, operating the operation button 913, or using the microphone 916 for voice input It can also be done by force, etc.

[0302] The portable information terminal 910 is selected from, for example, a telephone, a notebook, or an information viewing device. It has multiple functions. Specifically, it can be used as a smartphone. The information terminal 910 can, for example, make mobile phone calls, send emails, view and create documents, play music, and view videos. It can run various applications such as playback, internet communication, and games. ru.

[0303] The camera 920 shown in Figure 8(D) consists of a housing 921, a display unit 922, operation buttons 923, and a shutter It has a shutter button 924, etc. The camera 920 also has a detachable lens 926. It is attached.

[0304] A light-emitting device manufactured using one aspect of the present invention can be used in the display unit 922. This allows for the manufacture of cameras with a high yield.

[0305] Here, it is possible to remove and replace the camera 920 and the lens 926 from the housing 921. Although this configuration was chosen, the lens 926 and the housing 921 may be integrated into a single unit.

[0306] Camera 920 captures still images or videos by pressing the shutter button 924. It is possible. In addition, the display unit 922 has the function of a touch panel, and the display unit 922 It is also possible to take an image by touching the screen.

[0307] Note that the Camera 920 can be fitted with a separate flash unit, viewfinder, etc. Yes, it is possible. Alternatively, these may be incorporated into the enclosure 921.

[0308] Figures 9(A) to (E) show electronic devices. These electronic devices are housed in a 9000 enclosure. Display unit 9001, speaker 9003, operation key 9005 (power switch or operation switch) (Including the switch), connection terminal 9006, sensor 9007 (force, displacement, position, velocity, acceleration, angle) Speed, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, electric current, Includes the ability to measure voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. It has a microphone (9008), etc.

[0309] A light-emitting device manufactured using one aspect of the present invention can be suitably used in the display unit 9001. This allows for the manufacture of electronic devices with a high yield.

[0310] The electronic devices shown in Figures 9(A) to (E) can have various functions. For example, Functions to display various information (still images, videos, text images, etc.) on the display unit, touch panel device Functions such as displaying calendar, date or time, and various software (programs) ) Functions to control processing, wireless communication function, and various computers using wireless communication function It has the ability to connect to a network and transmit or receive various types of data using wireless communication. The function to be performed is to read the program or data recorded on the recording medium and display it on the display unit. It can have functions such as the following. Furthermore, the electronic devices shown in Figures 9(A) to (E) have The functions are not limited to these, and other functions may also be present.

[0311] Figure 9(A) shows the wristwatch-type personal information terminal 9200, and Figure 9(B) shows the wristwatch-type personal information terminal These are perspective views showing each of the 9201 models.

[0312] The mobile information terminal 9200 shown in Figure 9(A) is used for mobile phone calls, email, document viewing and creation, Various applications such as music playback, internet communication, and computer games are implemented. It can be done. Also, the display unit 9001 has a curved display surface, and the curved The display can be shown along the display surface. Furthermore, the 9200 mobile information terminal is based on communication standards. It is possible to perform short-range wireless communication. For example, with a wireless communication-enabled headset. By communicating with each other, hands-free calls are also possible. Furthermore, the mobile information terminal 9 200 has a connection terminal 9006 and can directly transmit data to other information terminals via a connector. It can be re-engineered. It can also be charged via connection terminal 9006. Oh, charging can also be done wirelessly without using the connection terminal 9006.

[0313] Unlike the mobile information terminal shown in Figure 9(A), the mobile information terminal 9201 shown in Figure 9(B) has a table The display surface of the display unit 9001 is not curved. Also, the outer shape of the display unit of the portable information terminal 9201 is It is not rectangular in shape (circular in Figure 9(B)).

[0314] Figures 9(C) to (E) are perspective views showing a foldable portable information terminal 9202. Oh, Figure 9(C) is a perspective view of the mobile information terminal 9202 in an unfolded state, and Figure 9(D) is a mobile The process of changing between the unfolded and folded states of the information terminal 9202. Figure 9(E) is a perspective view of the state in which the mobile information terminal 9202 is folded. be.

[0315] The 9202 personal digital assistant offers excellent portability when folded, and when unfolded, the seams are seamless. The wide display area without any obstructions provides excellent readability of the display. (Display unit of the portable information terminal 9202) The 9001 is supported by three housings 9000 connected by hinges 9055. By bending the two housings 9000 via the hinge 9055, the portable information terminal 9 The 202 can be reversibly transformed from an unfolded state to a folded state. For example, The portable information terminal 9202 can be bent with a radius of curvature of 1 mm or more and 150 mm or less.

[0316] This embodiment can be combined with other embodiments as appropriate.

[0317] (Embodiment 5) This embodiment describes an example of applying a light-emitting element according to one aspect of the present invention to various lighting devices. This will be explained using Figures 10 and 11. By using a light-emitting element, which is one aspect of the present invention... This allows for the creation of highly reliable lighting devices with excellent luminous efficiency.

[0318] A light-emitting element according to one aspect of the present invention is fabricated on a flexible substrate, thereby having a curved surface. This enables the realization of electronic devices and lighting devices that have a light-emitting region.

[0319] Furthermore, a light-emitting device using a light-emitting element according to one embodiment of the present invention can also be applied to the lighting of automobiles. This allows for, for example, the installation of lighting on the windshield, ceiling, etc.

[0320] Figure 10(A) shows a perspective view of one side of the multi-function terminal 3500, and Figure 10(B) shows a multi This shows a perspective view of the other side of the functional terminal 3500. The multifunctional terminal 3500 is housed in a casing 350. The display unit 3504, camera 3506, lighting 3508, etc. are incorporated into 2. The light-emitting device of the form can be used for illumination 3508.

[0321] The illumination 3508 functions as a surface light source by using a light-emitting device according to one aspect of the present invention. Therefore, point light sources, such as LEDs (Light Emitting Diodes), Unlike the above, it can produce light with less directionality. For example, if you connect the illumination 3508 and the camera 3506 When used in combination, the light 3508 is turned on or flashed, and the camera 3506 is used to... It can be imaged. As illumination 3508, it has the function of a surface light source, so You can take photos that look like they were taken in natural light.

[0322] Note that the multi-function terminal 3500 shown in Figures 10(A) and (B) is shown in Figures 9(A) to 9(C). Similar to the electronic devices shown, it can have a variety of functions.

[0323] Furthermore, inside the housing 3502 are a speaker and sensors (force, displacement, position, velocity, acceleration, angle). Speed, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, electric current, Includes functions for measuring voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. It can have a microphone, etc. Also, inside the multifunction terminal 3500, By providing a detection device that has sensors for detecting tilt, such as gyroscopes and accelerometers, The orientation (portrait or landscape) of the functional terminal 3500 is determined, and the screen display of the display unit 3504 is automatically adjusted. It can be made to switch between modes.

[0324] The display unit 3504 can also function as an image sensor. For example, the display unit 3 By touching the 504 with their palm or fingers, the user can be authenticated by capturing images of their palm print, fingerprints, etc. Furthermore, the display unit 3504 is equipped with a backlight that emits near-infrared light or a sensor that emits near-infrared light. By using a light source for imaging, it is also possible to image finger veins, palmar veins, etc. Note that the display unit 35 A light-emitting device according to one aspect of the present invention may be applied to 04.

[0325] Figure 10(C) shows a perspective view of the 3600 security light. The 3600 light is, The housing 3602 has lighting 3608 on its exterior, and the housing 3602 incorporates a speaker 3610, etc. It is incorporated. A light-emitting element according to one aspect of the present invention can be used in illumination 3608.

[0326] Light 3600, for example, grips, grasps, or holds Light 3608. It can emit light by doing so. Also, inside the housing 3602, from light 3600 The device may also include an electronic circuit capable of controlling the method of light emission. For example, the electronic circuit may be one Alternatively, the circuit may be designed to emit light intermittently multiple times, or the current value of the light emission may be controlled. This may result in a circuit that allows the amount of light emitted to be adjusted. Also, the light emitted from the lighting 3608 and At the same time, you could incorporate a circuit that outputs a loud alarm sound from speaker 3610. stomach.

[0327] As for the Light 3600, it can emit light in any direction, so for example, against an assailant It can be used to intimidate animals with light, or light and sound. Additionally, the Light 3600 has digital capabilities. The device may also have a camera function, such as a chill camera, to enable shooting.

[0328] Figure 11 shows an example in which a light-emitting element is used as an indoor lighting device 8501. Because it can be scaled up to cover a large area, it can also be used to form large-area lighting devices. In addition, curved surfaces By using a housing having the above characteristics, a lighting device 8502 having a curved surface in the light-emitting area can be formed. This is also possible. The light-emitting element shown in this embodiment is a thin film, which allows for a high degree of freedom in the design of the housing. Therefore, lighting devices with various elaborate designs can be created. Furthermore, indoor A large lighting fixture 8503 may be installed on the wall. Also, lighting fixtures 8501, 8502, 8 A touch sensor may be provided in 503 to turn the power on or off.

[0329] Furthermore, by using the light-emitting element on the surface side of the table, it is equipped with the functionality of a table. It can be a lighting device 8504. Furthermore, light-emitting elements can be used in other parts of the furniture. This allows for the creation of a lighting device that also functions as furniture.

[0330] As described above, a lighting device and an electronic device are obtained by applying a light-emitting device according to one aspect of the present invention. This is possible. The applicable lighting devices and electronic equipment are those shown in this embodiment. It is not limited to that; it can be applied to electronic devices in all fields.

[0331] Furthermore, the configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there. [Examples]

[0332] This embodiment provides an example of fabricating a light-emitting element, which is a type of electronic device according to one aspect of the present invention, and The characteristics of the light-emitting element will be described. Furthermore, the refractive index of the organic compound used in the hole injection layer and The refractive index of the hole injection layer will be explained. Figure 2(A) shows a cross-sectional view of the device structure fabricated in this embodiment. The details of the device structure are shown in Table 1. The structures and abbreviations of the compounds used are also shown below. See below.

[0333] [ka]

[0334] [Table 1]

[0335] [Table 2]

[0336] [Table 3]

[0337] <Measuring refractive index> Comparative light-emitting element 1 to comparative light-emitting element 4, light-emitting element 5 to light-emitting element 8, and light-emitting element 9 to light-emitting element The refractive index of the hole injection layer 111 of the element 12 and the organic compound used in the hole injection layer 111 were measured. The refractive index is measured using a JAWoolam rotating compensator type multi-incidence angle high-speed spectroscopic ellipsometer. Measurements were taken at room temperature using an M-2000U. The measurement sample was prepared by vacuum deposition on a quartz substrate. Prepared. Measuring n Ordinary and n Extraordinary, na The verage was calculated.

[0338] Figure 12 shows the results of refractive index measurements of each film using light at a wavelength of 532 nm. A comparison can be made using Figure 12. The DBT3P-II used in light-emitting element 1 to comparative light-emitting element 4 has the highest refractive index. It was found that the dmCBP used in light-emitting elements 5 to 8 was n Ordinary It was found that the organic compound has a low refractive index of 1.75 or less. Also, the light-emitting element 9 The TAPC used in the light-emitting element 12 is very ordinary, with n being 1.70 or less. It was found to be an organic compound with a low refractive index.

[0339] Furthermore, since the hole injection layer 111 is required to have hole injection properties, it must have an electron-donating material. Preferred. Hole injection layer of each light-emitting element using MoO3 with a high refractive index as the electron-donating material. 111 is expected to have a high refractive index. However, as shown in Figure 12, the hole injection layer 1 of each light-emitting element The refractive index of the film in which MoO3 (which is 11) is added to each organic compound is the refractive index of each organic compound It was found that the refractive index increased only slightly compared to that of the material. That is, the hole injection layer 111 By using an organic compound with a low refractive index, an electron-donating material can be made into a material with a high refractive index. It was found that a hole injection layer 111 with a low refractive index can be obtained even when using [a specific method / tool].

[0340] Furthermore, as shown in Figure 12, the hole injection layer 111 of each light-emitting element is n greater than the film of the respective organic compound. It was found that the difference between Ordinary and n Extraordinary is small. In contrast to an organic compound film, a mixed film of MoO3, an electron-accepting material, exhibits different characteristics. It was found that the directional properties decreased.

[0341] <Fabrication of light-emitting elements> <<Fabrication of comparative light-emitting elements 1 to 4>> An ITSO film was formed on a glass substrate as electrode 101, with a thickness of 70 nm. The electrode area of ​​electrode 101 is 4 mm². 2 (2mm x 2mm) was used. The refractive index (n Ordinary) of the film at a wavelength of 532 nm is 2.07.

[0342] Next, a hole injection layer 111 is placed on electrode 101, consisting of 1,3,5-tri-(4-dibenzothi Ophenyl-benzene (abbreviation: DBT3P-II) and MoO3 are mixed in a weight ratio (DBT The 3P-II:MoO3 ratio is set to 2:0.5, and the thickness is set to x1 nm. The material was deposited. Note that the value of x1 differs for each light-emitting element, and the value of x1 for each light-emitting element is The values ​​are shown in Table 2.

[0343] Next, a hole transport layer 112 is made on the hole injection layer 111, with PCCP having a thickness of 20 nm. It was vapor-deposited in that manner.

[0344] Next, as the light-emitting layer 130(1) on the hole transport layer 112, 4,6mCzP2Pm and P CCP and Ir(pbi-diBuCNp)3 (a mixture of fac isomer and mer isomer in a 3:2 ratio) The weight ratio (4,6mCzP2Pm:PCCP:Ir(pbi-diBuCNp)3) is 0. Co-depositing was performed in a ratio of 5:0.5:0.1 and with a thickness of 20 nm, followed by As the optical layer 130(2), the weight ratio is (4,6mCzP2Pm:PCCP:Ir(pbi-d The ratio of iBuCNp3) is 0.8:0.2:0.1, and the thickness is 20 nm. Co-deposited in the manner described above. In addition, in the light-emitting layer 130(1) and light-emitting layer 130(2), Ir( pbi-diBuCNp)3 is a guest material that exhibits phosphorescence.

[0345] Next, on the light-emitting layer 130(2), a first electron transport layer 118(1) is provided, with a 4,6 mCz P2Pm was co-deposited to a thickness of 20 nm. Subsequently, the first electron transport layer 118( 1) A second electron transport layer 118(2) is made of bathophenanthroline (abbreviated as BPhe). n) was deposited to a film thickness of 10 nm.

[0346] Next, on the second electron transport layer 118(2), lithium fluoride is added as an electron injection layer 119. LiF was deposited to a thickness of 1 nm.

[0347] Next, on the electron injection layer 119, an electrode 102 made of aluminum (Al) with a thickness of 20 It was formed to have a wavelength of 0 nm.

[0348] Next, the glove box is sealed using an organic EL sealing material in a nitrogen atmosphere. By fixing the glass substrate for this purpose onto a glass substrate on which an organic material has been formed, comparative light-emitting element 1 Or the comparative light-emitting element 4 was sealed. Specifically, the organic material on the glass substrate formed on the organic material A sealing material is applied around the material, and the substrate and the glass substrate for sealing are bonded together, and the wavelength is 365nm ultraviolet light at 6 J / cm² 2 The material was irradiated and then heat-treated at 80°C for 1 hour. Comparative light-emitting elements 1 to 4 were obtained.

[0349] <<Fabrication of light-emitting elements 5 to 8>> The manufacturing process for light-emitting elements 5 to 8 is the same as the manufacturing process for comparative light-emitting elements 1 to 4. The only difference is the process of fabricating the hole injection layer 111; the other processes are the same for the comparative light-emitting element 1 to the comparative light-emitting element The procedure was the same as for child 4.

[0350] On electrode 101, a hole injection layer 111(1) is formed by dmCBP and MoO3 in a weight ratio ( The dmCBP:MoO3 ratio is set to 2:0.5, and the thickness is set to 35 nm. Deposition is performed, followed by the application of DBT3P-II and MoO3 in a weight ratio (DBT3P-II:MoO3). 3) was co-deposited so that the ratio was 2:0.5 and the thickness was x2nm. The value of x2 varies depending on the light-emitting element, and the value of x2 for each light-emitting element is shown in Table 3. .

[0351] <<Fabrication of light-emitting elements 9 to 12>> The manufacturing process for light-emitting elements 9 to 12 is the manufacturing process for comparative light-emitting elements 1 to 4. The only difference is the process and the process for fabricating the hole injection layer 111; the other processes are the same for the comparative light-emitting element 1 to the comparative light-emitting element. The procedure was the same as for element 4.

[0352] On electrode 101, a hole injection layer 111(1) is formed by TAPC and MoO3 in a weight ratio (T Co-deposited so that the APC:MoO3 ratio is 2:0.5 and the thickness is 35 nm. Next, the weight ratio of DBT3P-II and MoO3 (DBT3P-II:MoO3) Co-deposited so that the ratio was 2:0.5 and the thickness was x2 nm. The value varies depending on the light-emitting element, and the x2 value for each light-emitting element is shown in Table 3.

[0353] <Characteristics of light-emitting elements> Next, the comparative light-emitting element 1 to comparative light-emitting element 4 and the light-emitting element 5 to light-emitting element 1 that were fabricated as described above. The characteristics of 2 were measured. Brightness and CIE chromaticity were measured using a colorimeter (Topcon, BM). A multi-channel spectrometer (Hamamatsu Photonics) is used to measure the field emission spectrum. A PMA-11 (manufactured by S Corporation) was used. Measurements of each light-emitting element were taken at room temperature (maintained at 23°C). It was done in a relaxed atmosphere.

[0354] From the fabricated light-emitting elements, the current efficiency of comparative light-emitting element 1, light-emitting element 5, and light-emitting element 9 was determined. The characteristics are shown in Figure 13. The current density-voltage characteristics are shown in Figure 14. Furthermore, the external quantum efficiency is also shown. -The luminance characteristics are shown in Figure 15. Note that the external quantum efficiency values ​​shown in Figure 15 have been corrected for the viewing angle. This is the external quantum efficiency measured from the front of the light-emitting element. As the organic compound in the inlet layer 111, comparative light-emitting element 1 uses DBT3P-II, and light-emitting element 5 uses d The device uses mCBP and TAPC for the light-emitting element 9, and the hole injection layer 111 is separate from the other element. All of these parts have the same element structure.

[0355] As shown in Figure 14, comparative light-emitting element 1, light-emitting element 5, and light-emitting element 9 have equivalent current density-voltage characteristics. It was found that this is the case. Therefore, an organic compound with a low refractive index is used in the hole injection layer 111. It was also found to possess good hole injection characteristics.

[0356] Furthermore, from Figures 13 and 15, comparative light-emitting element 1, light-emitting element 5, and light-emitting element 9 are 100 cd / It was found to have a high current efficiency exceeding A and a high external quantum efficiency exceeding 30%. Furthermore, dmCBP and TAPC, which are organic compounds with low refractive indices, were used in the hole injection layer 111. The light-emitting elements 5 and 9 are comparative light-emitting elements using DBT3P-II, a material with a high refractive index. It showed higher efficiency than optical element 1.

[0357] Furthermore, 25 mA / cm² was supplied to comparative light-emitting element 1, light-emitting element 5, and light-emitting element 9. 2 Current at current density Figure 16 shows the emission spectrum when the current is passed through. As shown in Figure 16, the comparative light-emitting element 1, The emission spectra of the photonic element 5 and the light-emitting element 9 have peaks around 515 nm and 550 nm. The guest material included in the light-emitting layer 130 is Ir(pbi-diBuCNp) It was found that the light originated from 3.

[0358] Furthermore, 1000 of the comparative light-emitting elements 1 to 4 and 5 to 12 cd / m 2 Table 4 shows the element characteristics in the vicinity. The external quantum efficiency shown in Table 4 is corrected for the field of view. The external quantum efficiency after the procedure is shown.

[0359] [Table 4]

[0360] Based on the above results, the comparative light-emitting elements 1 to 4 and 5 fabricated in this embodiment The light-emitting element 12 exhibits good driving voltage and luminous efficiency regardless of the structure of the hole injection layer 111. It is clear that they are doing so.

[0361] <Relationship between the refractive index of the hole injection layer 111 and the external quantum efficiency> Figure 17 shows the values ​​for each element shown in Table 4, and the organic material used in each hole injection layer 111. The relationship between chromaticity x and external quantum efficiency is shown. In Figure 17, the data for the curve of "DBT3P-II" is shown. The values ​​of comparative light-emitting elements 1 to 4 are shown, and the data for the "dmCBP" curve are shown. The values ​​of elements 5 through 8 are included in the data for the "TAPC" curve, and the values ​​of elements 9 through 8 are included in the data for the "TAPC" curve. Twelve values ​​were used, respectively. Here, the comparison light-emitting elements 1 to 4 and the light-emitting elements In the 5 to 12 light-emitting elements, even if the thickness of the hole injection layer 111 is the same, the Because the refractive index differs depending on the compound, the optical path length from the light-emitting region of each light-emitting element to the substrate is It changes. As the optical path length changes, the external quantum efficiency also changes, and therefore the refraction of the hole injection layer 111 changes. When evaluating the relationship between the rate and the external quantum efficiency, it is necessary to adjust the optical path length in each light-emitting element, Fine-tuning the EL layer thickness through the fabrication of light-emitting elements is difficult.

[0362] In light-emitting devices using the same light-emitting material, the optical path length from the light-emitting region of each light-emitting device to the substrate is If they differ, differences will also occur in the emission spectrum and chromaticity obtained from the light-emitting element. On the other hand, When the same chromaticity is obtained from each light-emitting element, the emission spectrum extracted from each light-emitting element The chromaticity is considered to be the same. That is, when the same chromaticity is obtained from each light-emitting element. Therefore, it can be said that the optical path length from the light-emitting region of each light-emitting element to the substrate is the same. Thus, the external quantum By considering the relationship between efficiency and chromaticity x or chromaticity y, the refractive index of the hole injection layer 111 and the external quantum It is possible to evaluate the relationship of efficiency.

[0363] Figure 12 shows that the organic compounds used in the hole injection layer 111 were DBT3P-II > dmCBP > TA. The refractive index is highest in the order of PC. Figure 17 shows that the refractive index of the organic compound used in the hole injection layer 111 is low. It was found that the more the light, the higher the external quantum efficiency. This is because of the light produced by the evanescent mode. This is because attenuation has been reduced and light extraction efficiency has improved.

[0364] In summary, by using an organic compound with a low refractive index in the hole injection layer 111, the hole injection characteristics are improved. It was found that a light-emitting element with good light extraction efficiency can be obtained while maintaining the same properties.

[0365] <Volume ratio of electron-donating material and electron-accepting material and external quantum efficiency in hole injection layer 111> Relationship > Here, the electron-accepting material (MoO3) relative to the electron-donating material in the hole injection layer 111 We investigated the relationship between the volume ratio (hereinafter referred to as the volume ratio of MoO3) and the external quantum efficiency. The detailed structure of the device is shown in Table 5. The structures and abbreviations of the compounds used are also shown below. For other organic compounds, please refer to the compounds mentioned above.

[0366] [ka]

[0367] [Table 5]

[0368] [Table 6]

[0369] <<Fabrication of light-emitting elements 13 to 18>> The manufacturing process of light-emitting elements 13 to 18 is the same as the manufacturing process of comparative light-emitting elements 1 to 4. The only differences are the manufacturing process and the process for creating the hole injection layer 111 and the light-emitting layer 130; other processes are the same for the comparison light-emitting element. The procedure was carried out in the same manner as for child 1 to comparison light-emitting element 4.

[0370] On electrode 101, a hole injection layer 111 is formed using DBT3P-II and MoO3 in a weight ratio (D The BT3P-II:MoO3) is configured to be 3-y:y, and the thickness is 40 nm. It was co-deposited. Note that the value of y differs for each light-emitting element, and the value of y in each light-emitting element is The values ​​are shown in Table 6. Table 6 also shows the results of converting the weight ratio to the volume ratio of MoO3. show.

[0371] Next, as the light-emitting layer 130(1) on the hole transport layer 112, 4,6mCzP2Pm and P CCP and Ir(tBuppm)3 in weight ratio (4,6mCzP2Pm:PCCP:Ir(t The ratio of Buppm)3) should be 0.5:0.5:0.075, and the thickness should be 20nm. Co-deposited in the manner described above, and then as the light-emitting layer 130(2), with a weight ratio of (4,6mCzP2Pm: PCCP:Ir(tBuppm)3) should be 0.8:0.2:0.075, and Co-deposited to a thickness of 20 nm. Note that the light-emitting layer 130(1) and light-emitting layer 130( In (2), Ir(tBuppm)3 is the guest material that exhibits phosphorescence.

[0372] <Characteristics of light-emitting elements> Next, the brightness-external quantum efficiency characteristics of the fabricated light-emitting elements 13 to 18 were measured. The measurements were taken using the method described above.

[0373] Figure 18 shows the 10,000 cd / m² readings for each element. 2 External quantum efficiency in the vicinity and hole injection layer 111 The relationship with the volume ratio of MoO3 is shown in Figure 18. From Figure 18, the volume ratio of MoO3 is related to electron-donating properties. In the region greater than 0 and less than or equal to 0.3 for matter, the external quantum efficiency is high, ranging from 24% to 26%. While it shows efficiency, it can be seen that efficiency decreases in the region greater than 0.3. In the region where the volume ratio of MoO3 is greater than 0.3, electron-accepting materials with a high refractive index (M Due to the influence of oO3, the refractive index of the hole injection layer 111 is increased, thus reducing the light extraction effect. This suggests that the rate is decreasing. On the other hand, the volume ratio of MoO3 is greater than 0 and above 0.3. In the lower region, the influence of electron-accepting materials with a high refractive index (MoO3) is small, and the refractive index is small. The refractive index of the electron-donating material is smaller than that of the electron-accepting material (MoO3) in the hole injection layer 11 Since it strongly influences the refractive index of 1, it suggests that the light extraction efficiency is good. That is, the volume ratio of MoO3 in the hole injection layer 111 is greater than 0 and has a concentration of 0.3 or less. By using this method, it is possible to create a light-emitting element with good light extraction efficiency. [Examples]

[0374] In this embodiment, as an electronic device according to one aspect of the present invention, a different light-emitting element from Example 1 is used as the electronic device according to one aspect of the present invention. This document describes an example of its fabrication and the characteristics of the light-emitting element. Furthermore, it explains the use of the hole injection layer 111. The refractive index of the compound and the refractive index of the hole injection layer will be explained. Furthermore, the details of the device structure will be shown. This is shown in 7. The structures and abbreviations of the compounds used are shown below. Note that for other organic compounds, Refer to Example 1 above.

[0375] [ka]

[0376] [Table 7]

[0377] [Table 8]

[0378] [Table 9]

[0379] <Measuring refractive index> Comparison light-emitting elements 19 to 22, light-emitting elements 23 to 26, and light-emitting element 2 The refractive index of the organic compound used in the hole injection layer 111 of the light-emitting element 7 to 30 was measured. The measurement was performed in the same manner as in Example 1.

[0380] Figure 19 shows the results of refractive index measurements of each film using light at a wavelength of 532 nm. A comparison can be made using Figure 19. The DBT3P-II used in the light-emitting element 19 to the comparative light-emitting element 22 has the highest refractive index. It was found that 9-[3-(9-phenyl] was used in light-emitting elements 23 to 26. -9H-fluoren-9-yl)phenyl]-9H-carbazole (abbreviation: mCzFLP) It has been found that n Ordinary is an organic compound with a low refractive index of 1.75 or less. Furthermore, the 4,4'-[bis(9-phenyl]] used in the light-emitting elements 27 to 30 Fluoren-9-yl)-triphenylamine (abbreviation: FLP2A) is n Ordin It was found that organic compounds with a low refractive index, where ary is 1.75 or less, are the ones in question.

[0381] Furthermore, from the results of Example 1, the hole injection layer 111 of the light-emitting elements 23 to 30 is mCzFLP or a mixed film of FLP2A and MoO3 exhibits similar refraction to each of the respective organic compounds. DBT3P has a rate and is the hole injection layer 111 of the comparative light-emitting element 19 to comparative light-emitting element 22. It is expected to have a lower refractive index than a mixed film of -II and MoO3.

[0382] <Fabrication of light-emitting elements> <<Fabrication of comparative light-emitting elements 19 to 22>> The manufacturing process for the comparative light-emitting elements 19 to 22 is as follows: Only the fabrication process for sub-layer 4 and the fabrication processes for the hole injection layer 111 and the light-emitting layer 130 differ; the other processes are similar. The procedure was carried out in the same manner as for Comparison Light-Emitting 1 to Comparison Light-Emitting 4.

[0383] On electrode 101, a hole injection layer 111 is formed by combining DBT3P-II and MoO3 in a weight ratio ( The ratio of DBT3P-II:MoO3 will be 2:0.5, and the thickness will be z1nm. Co-deposited onto sea urchin. Note that the value of z1 differs for each light-emitting element, and the z1 value for each light-emitting element is... The values ​​are shown in Table 8.

[0384] Next, as the light-emitting layer 130(1) on the hole transport layer 112, 4,6mCzP2Pm and P CCP and Ir(ppy)3 in weight ratio (4,6 mCzP2Pm:PCCP:Ir(ppy)3) 3) Co-deposit the material so that the ratio is 0.5:0.5:0.1 and the thickness is 20 nm. Next, as the light-emitting layer 130(2), the weight ratio is (4,6mCzP2Pm:PCCP:Ir( ppy)3) should be 0.8:0.2:0.1 and the thickness should be 20 nm. Co-deposition was performed. In addition, in the light-emitting layer 130(1) and light-emitting layer 130(2), Ir(ppy )3 is a guest material that exhibits phosphorescence.

[0385] <<Fabrication of light-emitting elements 23 to 26>> The manufacturing process for the light-emitting elements 23 to 26 is carried out using the above-mentioned comparative light-emitting elements 19 to 22 The only differences are the fabrication process of the comparison light-emitting element 19 to the fabrication process of the hole injection layer 111; the other processes are the same. The procedure was the same as for the comparative light-emitting element 22.

[0386] On electrode 101, a hole injection layer 111(1) is formed by mCzFLP and MoO3 in a weight ratio ( The ratio of mCzFLP (MoO3) is 2:0.5, and the thickness is 35nm. Co-deposited, followed by DBT3P-II and MoO3 in a weight ratio (DBT3P-II:MoO3). Co-deposited O3) was performed so that the ratio was 2:0.5 and the thickness was z2 nm. The value of z2 differs for each light-emitting element, and the value of z2 for each light-emitting element is shown in Table 9. ru.

[0387] <<Fabrication of light-emitting elements 27 to 30>> The manufacturing process for the light-emitting elements 27 to 30 is carried out using the above-mentioned comparative light-emitting elements 19 to 22 The only differences are the fabrication process of the comparison light-emitting element 19 to the fabrication process of the hole injection layer 111; the other processes are the same. The procedure was the same as for the comparative light-emitting element 22.

[0388] On electrode 101, a hole injection layer 111(1) is formed by FLP2A and MoO3 in a weight ratio (F Co-evaporation is performed so that the ratio of LP2A to MoO3 is 2:0.5 and the thickness is 35 nm. Next, we measured DBT3P-II and MoO3 in weight ratio (DBT3P-II:MoO3 Co-deposited the material so that the ratio of ) was 2:0.5 and the thickness was z2 nm. The value of z2 varies depending on the light-emitting element, and the value of z2 for each light-emitting element is shown in Table 9.

[0389] <Characteristics of light-emitting elements> Next, the comparison light-emitting elements 19 to 22 and 23 to 22 fabricated above The characteristics of element 30 were measured. The measurement was performed in the same manner as in Example 1.

[0390] From among the fabricated light-emitting elements, the current effect of comparison light-emitting element 19, light-emitting element 23, and light-emitting element 27 The rate-luminance characteristics are shown in Figure 20. The current density-voltage characteristics are shown in Figure 21. Furthermore, external quantities... The quantum efficiency-luminance characteristics are shown in Figure 22. Note that the external quantum efficiency values ​​shown in Figure 22 are corrected for the field of view. This is the external quantum efficiency measured from the front of the light-emitting element, which has not been performed. As the organic compound of the hole injection layer 111, the comparative light-emitting element 19 uses DBT3P-II, and the light-emitting element Sub-element 23 is an element using an mCzFLP, and light-emitting element 27 is an element using an FLP2A, and hole All parts except for the injection layer 111 have the same element structure.

[0391] As shown in Figure 21, the comparison light-emitting element 19, light-emitting element 23, and light-emitting element 27 have equivalent current density-voltage characteristics. It was found to possess the property. Therefore, similar to Example 1, the hole injection layer 111 has a refractive index. It was found that even when using organic compounds with low saturation, they exhibit good hole injection characteristics.

[0392] Furthermore, from Figures 20 and 22, the comparison light-emitting element 19, light-emitting element 23, and light-emitting element 27 are 100 It has been found to have high current efficiency of around cd / A and high external quantum efficiency exceeding 25%. Furthermore, mCzFLP and FLP2A, which are organic compounds with low refractive index, were used in the hole injection layer 1. The light-emitting elements 23 and 27 used in 11 are made of DBT3P-II, a material with a high refractive index. It showed higher efficiency than the comparative light-emitting element 19 used.

[0393] Additionally, 25 mA / cm² is supplied to the comparison light-emitting element 19, light-emitting element 23, and light-emitting element 27. 2 At the current density Figure 23 shows the emission spectrum when current is applied. As shown in Figure 23, the comparison light-emitting element 1 9. The emission spectra of light-emitting elements 23 and 27 have a peak around 518 nm. Furthermore, the emission originates from Ir(ppy)3, a guest material contained in the light-emitting layer 130. It was discovered that...

[0394] Also, one of the comparative light-emitting elements 19 to 22 and 23 to 30 000 cd / m 2 Table 10 shows the element characteristics in the vicinity.

[0395] [Table 10]

[0396] Based on the above results, the comparative light-emitting elements 19 to 22 and the light-emitting elements fabricated in this embodiment Regardless of the structure of the hole injection layer 111, the light-emitting elements 23 to 30 have good driving voltage and light-emitting effect. It can be seen that it is showing a rate.

[0397] <Relationship between the refractive index of the hole injection layer 111 and the external quantum efficiency> Figure 24 shows the values ​​for each element shown in Table 10, and the organic material used in each hole injection layer 111 Next, the relationship between chromaticity x and external quantum efficiency is shown. In Figure 24, the data of the curve for "DBT3P-II" The values ​​of the comparative light-emitting elements 19 to 22 are shown in the curve data for "mCzFLP". The values ​​of light-emitting elements 23 to 26 are shown, and the data for the curve of "FLP2A" are shown for the light-emitting elements. The values ​​of 27 to 30 were used respectively.

[0398] Figure 19 shows that the organic compound used in the hole injection layer 111 was DBT3P-II>mCzFLP>F The refractive index is highest in the order of LP2A. As shown in Figure 24, the same as in Example 1, the material used in the hole injection layer 111 is It was found that the lower the refractive index of the compound, the higher the external quantum efficiency. This was discovered by Evanesse. This is because the attenuation of light due to the vent mode is reduced, and the light extraction efficiency is improved.

[0399] In summary, by using an organic compound with a low refractive index in the hole injection layer 111, the hole injection characteristics are improved. It was found that a light-emitting element with good light extraction efficiency can be obtained while maintaining the same properties. [Examples]

[0400] This embodiment provides an example of fabricating a light-emitting element, which is a type of electronic device according to one aspect of the present invention, and The characteristics of the light-emitting element will be described. Furthermore, the refractive index of the organic compound used in the hole injection layer and The refractive index of the hole injection layer will be explained. Figure 2(A) shows a cross-sectional view of the device structure fabricated in this embodiment. The details of the device structure are shown in Tables 11 to 14. The abbreviations for "construction" should be determined by referring to the above-described embodiments and examples.

[0401] [Table 11]

[0402] [Table 12]

[0403] [Table 13]

[0404] [Table 14]

[0405] <Measuring refractive index> Comparison light-emitting elements 31 to 34, light-emitting elements 35 to 38, light-emitting elements 39 Light-emitting elements 42, 43 to 46, comparison light-emitting elements 47 to comparison light-emitting elements 50 Organic compounds used in hole injection layer 111 and comparative light-emitting elements 31 to 34 , light-emitting elements 35 to 38, light-emitting elements 39 to 42, light-emitting elements 43 to Refraction of the hole injection layer 111 used in the optical element 46 and the comparative light-emitting element 47 to 50 The ratio was measured. The refractive index was measured in the same manner as described in Example 1.

[0406] Figure 25 shows the results of refractive index measurements of each film using light at a wavelength of 532 nm. Comparison from Figure 25 The DBT3P-II used in the light-emitting element 31 to the comparative light-emitting element 34 has the highest refractive index. It was found that CzC was used in light-emitting elements 35 to 38, and light-emitting elements 39 to CzSi used in light-emitting element 42, FATPA used in light-emitting elements 43 to 46, ratio 1,4-di(triphenylsilyl)benzase used in comparative light-emitting elements 47 to 50 n (abbreviation: UGH-2) is a refractive index where n Ordinary is 1.70 or less in all cases. It was found to be an organic compound with very low levels of organic compounds.

[0407] Furthermore, since the hole injection layer 111 is required to have hole injection properties, it must have an electron-donating material. Preferred. Hole injection layer of each light-emitting element using MoO3 with a high refractive index as the electron-donating material. 111 is expected to have a high refractive index. However, as shown in Figure 25, the hole injection layer 1 of each light-emitting element The refractive index of the film in which MoO3 (which is 11) is added to each organic compound is the refractive index of each organic compound It was found that the refractive index increased only slightly compared to that of the material. That is, the hole injection layer 111 By using an electron-donating material with a low refractive index, the electron-donating material can be used to It was found that a hole injection layer 111 with a low refractive index can be obtained even when mixing materials with a high refractive index.

[0408] Furthermore, as shown in Figure 25, the hole injection layer 111 of each light-emitting element is n greater than the film of the respective organic compound. It was found that the difference between Ordinary and n Extraordinary is small. However, a mixed film of MoO3, an electron-donating material, and an organic compound differs from an organic compound film in that it exhibits different properties. It was found that the directional properties decreased.

[0409] Furthermore, the organic compound Cz used in the hole injection layer 111 of the light-emitting elements 39 to 42 Si and organic compounds used in the hole injection layer 111 of comparative light-emitting elements 47 to 50 The mixed film of UGH-2 and MoO3 has a refractive index similar to that of each organic compound, and DBT3P-II and MoO3 are the hole injection layers 111 of the comparative light-emitting elements 1 to 4. It is expected to have a lower refractive index than the mixed film.

[0410] <Fabrication of light-emitting elements> <<Fabrication of comparative light-emitting elements 31 to 34>> An ITSO film was formed on a glass substrate as electrode 101, with a thickness of 70 nm. The electrode area of ​​electrode 101 is 4 mm². 2 (2mm x 2mm)

[0411] Next, a hole injection layer 111 is placed on electrode 101, consisting of 1,3,5-tri-(4-dibenzothi Ophenyl-benzene (abbreviation: DBT3P-II) and MoO3 are mixed in a weight ratio (DBT The 3P-II:MoO3 ratio is set to 2:0.5, and the thickness is set to x3nm. The material was deposited. Note that the value of x3 differs for each light-emitting element, and the value of x3 for each light-emitting element is The values ​​are shown in Table 13.

[0412] Next, a hole transport layer 112 is made on the hole injection layer 111, with PCCP having a thickness of 20 nm. It was vapor-deposited in that manner.

[0413] Next, as the light-emitting layer 130(1) on the hole transport layer 112, 4,6mCzP2Pm and P CCP and Ir(ppy)3 in weight ratio (4,6 mCzP2Pm:PCCP:Ir(ppy)3) 3) Co-deposit the material so that the ratio is 0.5:0.5:0.1 and the thickness is 20 nm. Next, as the light-emitting layer 130(2), the weight ratio is (4,6mCzP2Pm:PCCP:Ir( ppy)3) should be 0.8:0.2:0.1 and the thickness should be 20 nm. Co-deposition was performed. In addition, in the light-emitting layer 130(1) and light-emitting layer 130(2), Ir(ppy )3 is a guest material that exhibits phosphorescence.

[0414] Next, on the light-emitting layer 130(2), a first electron transport layer 118(1) is provided, with a 4,6 mCz P2Pm was co-deposited to a thickness of 20 nm. Subsequently, the first electron transport layer 118( 1) A second electron transport layer 118(2) is made of bathophenanthroline (abbreviated as BPhe). n) was deposited to a film thickness of 10 nm.

[0415] Next, on the second electron transport layer 118(2), lithium fluoride is added as an electron injection layer 119. LiF was deposited to a thickness of 1 nm.

[0416] Next, on the electron injection layer 119, an electrode 102 made of aluminum (Al) with a thickness of 20 It was formed to have a wavelength of 0 nm.

[0417] Next, the glove box is sealed using an organic EL sealing material in a nitrogen atmosphere. By fixing the glass substrate for this purpose onto a glass substrate on which an organic material has been formed, comparative light-emitting element 3 1 to 34 comparative light-emitting elements were sealed. Specifically, the organic material was formed on a glass substrate. A sealing material is applied around the equipment material, and the substrate and the glass substrate for sealing are bonded together, creating a wave The length is 6 J / cm² of ultraviolet light at 365 nm. 2 The material was irradiated and then heat-treated at 80°C for 1 hour. Comparative light-emitting elements 31 to 34 were obtained accordingly.

[0418] <<Fabrication of light-emitting elements 35 to 46 and comparative light-emitting elements 47 to 50>> The manufacturing process for light-emitting elements 35 to 46 and comparative light-emitting elements 47 to 50 is as follows: The manufacturing process of the above comparative light-emitting elements 31 to 34 and the manufacturing process of the hole injection layer 111 Except for the difference, the other processes were carried out in the same manner as for the comparative light-emitting elements 31 to 34. Element structure The details are shown in Tables 11 to 14, so the details of the manufacturing method are omitted.

[0419] <Characteristics of light-emitting elements> Next, the comparative light-emitting elements 31 to 34 and 35 to light-emitting elements fabricated above The characteristics of child 46 and comparative light-emitting elements 47 to 50 were measured. The measurements were performed in Example 1 and The same procedure was followed.

[0420] From the fabricated light-emitting elements, we selected comparison light-emitting element 31, light-emitting element 35, light-emitting element 39, and light-emitting element. Figure 26 shows the current efficiency-luminance characteristics of sub-element 43 and comparative light-emitting element 47. Also, the current density-luminance characteristics are shown. The pressure characteristics are shown in Figure 27. The external quantum efficiency-luminance characteristics are shown in Figure 28. Note that Figure 28 shows... The external quantum efficiency values ​​shown are measured from the front of the light-emitting element without field-of-view correction. This is the external quantum efficiency when this occurs. Also, as the organic compound of the hole injection layer 111, comparative luminescence Element 31 is DBT3P-II, light-emitting element 35 is CzC, light-emitting element 39 is CzSi, The optical element 43 uses FATPA, and the comparison light-emitting element 47 uses UGH-2. The entire device structure is the same except for the hole injection layer 111.

[0421] From Figures 26 and 28, comparative light-emitting element 31, light-emitting element 35, light-emitting element 39, and light-emitting element 43 The comparative light-emitting element 47 has a high current efficiency of over 90 cd / A and a high external current efficiency of over 25%. It was found to have quantum efficiency. In addition, an organic compound with a low refractive index was used in the hole injection layer 11 The light-emitting elements 35, 39, 43, and comparative light-emitting element 47 used in 1 have a refractive index It showed higher efficiency than the comparative light-emitting element 31, which uses DBT3P-II, a high-performance material. This is achieved by using an organic compound with a low refractive index in the hole injection layer 111 to produce evanescent waves. This suggests that the attenuation of light due to the light source is being suppressed.

[0422] Furthermore, as shown in Figure 27, comparative light-emitting element 31, light-emitting element 35, light-emitting element 39 and light-emitting element 43 are It was found to have equivalent good current density-voltage characteristics. On the other hand, the comparison light-emitting element 47 The current density is compared to the comparative light-emitting elements 31, 35, 39, and 43. The voltage characteristics were found to be degraded, indicating low hole injection capability. This is because UGH-2 is molecular This is because it does not contain electron-donating groups. Therefore, it does not contain electron-donating groups in the molecule. Therefore, even if a material with a low refractive index is used in the hole injection layer 111, good hole injection characteristics can be obtained. It was found that a hole injection layer 111 could be fabricated.

[0423] Also, the comparison light-emitting element 31, light-emitting element 35, light-emitting element 39, light-emitting element 43 and the comparison light-emitting element 47 at 25mA / cm 2 Figure 29 shows the emission spectrum when a current is passed through at the given current density. As shown in Figure 29, comparative light-emitting element 31, light-emitting element 35, light-emitting element 39, light-emitting element 43 and The emission spectrum of the comparative light-emitting element 47 has a peak around 518 nm, and the light-emitting layer It was found that the luminescence originates from Ir(ppy)3, a guest material contained in 130. .

[0424] Furthermore, comparative light-emitting elements 31 to 34, light-emitting elements 35 to 46 and relative 1000 cd / m² of comparison light-emitting element 47 to comparison light-emitting element 50 2 Table 1 shows the element characteristics in the vicinity. This is shown in 5. The external quantum efficiencies shown in Table 15 represent the external quantum efficiencies after field-of-view correction.

[0425] [Table 15]

[0426] Based on the above results, the comparative light-emitting elements 31 to 34 and 34, which were fabricated in this embodiment, are shown below. 5 to 46 and comparative light-emitting elements 47 to 50 are part of the hole injection layer 111 Regardless of the structure, it can be seen that good drive voltage and luminous efficiency are observed.

[0427] <Reliability of light-emitting elements> Next, the comparison light-emitting element 31, light-emitting element 35, light-emitting element 39, light-emitting element 43 and the comparison light-emitting element A constant current drive test was performed on unit 47 at 2mA. The results are shown in Figure 30. From Figure 30, The reliability of the comparison light-emitting element 31, light-emitting element 35, light-emitting element 39, and light-emitting element 43 is determined by the comparison light-emitting element It was found to have better reliability compared to child 47. In particular, the reliability of light-emitting element 43 was good. It was found that, as mentioned above, the comparison light-emitting element 31, light-emitting element 35, light-emitting element 39, The organic compound used in the hole injection layer 111 of the optical element 43 has an electron-donating group within its molecule. Therefore, compared to UGH-2 used in the comparative light-emitting element 47, the hole injection properties are better. Therefore, it is thought that a better hole injection capability of the hole injection layer 111 leads to greater reliability of the light-emitting element. It was found that the performance was good. Note that in Figure 30, the comparison light-emitting element 31 and light-emitting element 35 The reliability test results for the light-emitting element 39 overlap.

[0428] <Relationship between the refractive index of the hole injection layer 111 and the external quantum efficiency> Figure 31 shows the values ​​for each element shown in Table 15, and the organic material used in each hole injection layer 111 Next, the relationship between chromaticity x and external quantum efficiency is shown. In Figure 31, the data of the curve for "DBT3P-II" The values ​​of the comparative light-emitting elements 31 to 34 are used in the "CzC" curve data. The values ​​of the light elements 35 to luminescent elements 38 are used in the data for the "CzSi" curve, and the luminescent elements 39 to The values ​​of the light-emitting element 42 are used in the data of the "FATPA" curve, and the values ​​of light-emitting elements 43 to 46 The values ​​of the "UGH-2" curve data are the values ​​of the comparison light-emitting elements 47 to 50. They were used respectively.

[0429] As shown in Figure 25, DBT3P-II, the organic compound used in the hole injection layer 111, has a refractive index of 1. Although they have a high refractive index of over 80, CzC, CzSi, FATPA, and UGH-2 It is an organic compound with a low refractive index of 1.70 or less. From Figure 31, DBT3P-II The hole injection layer 111 uses an organic compound with a lower refractive index than the light-emitting element used in the hole injection layer 111. It was found that the light-emitting element using Evane has a higher external quantum efficiency. This is because the attenuation of light due to the emission mode is reduced, and the light extraction efficiency is improved.

[0430] In summary, the hole injection layer 111 contains a tetraarylmethane skeleton or a tetraarylsilane skeleton. By using either one of them and an organic compound having an electron-donating group, hole injection characteristics can be achieved. It was found that a light-emitting element with good light extraction efficiency and reliability can be obtained while maintaining performance. . [Examples]

[0431] This embodiment provides an example of fabricating a light-emitting element, which is a type of electronic device according to one aspect of the present invention, and The characteristics of the light-emitting element will be described. Furthermore, the refractive index of the organic compound used in the hole injection layer and The refractive index of the hole injection layer will be explained. Figure 2(A) shows a cross-sectional view of the device structure fabricated in this embodiment. The details of the device structure are shown in Tables 16 and 17. The structures of the compounds used are also shown. The names are shown below. For other organic compounds, please refer to the previous examples and embodiments. That is fine. Note that the light-emitting element shown in this embodiment does not use a metal oxide in the hole injection layer 111, It is composed solely of organic compounds.

[0432] [ka]

[0433] [Table 16]

[0434] [Table 17]

[0435] <Measuring refractive index> Comparison light-emitting elements 51 to 54, comparison light-emitting elements 55 to 58, light emission Refractive index of the hole injection layer 111 of elements 59 to 62 and 63 to 66 The refractive index was measured in the same manner as described in Example 1. The wavelength was 633 nm. Table 18 shows the refractive index (n Ordinary) values ​​of each film in relation to light.

[0436] [Table 18]

[0437] Table 18 shows the N,N,N',N'-tetrahedron used in comparative light-emitting elements 51 to 54. Lanafthalen-2-ylbenzidine (abbreviation: β-TNB) and p-dopant (analysis) The mixed film and the NP used in the comparative light-emitting elements 55 to 58 (purchased from Kobo Co., Ltd.) The mixed film of B and p-dopant has a refractive index greater than 1.75, and thus possesses a high refractive index. It was found that BPAFLP and p-dop were used in the light-emitting elements 59 to 62. The mixed film of ant and the TAPC and p-dopan used in light-emitting elements 63 to 66. The refractive index of the mixed film t was found to be lower than 1.75, indicating a low refractive index. .

[0438] <Fabrication of light-emitting elements> <<Fabrication of comparative light-emitting elements 51 to 54>> An ITSO film was formed on a glass substrate as electrode 101, with a thickness of 70 nm. The electrode area of ​​electrode 101 is 4 mm². 2 (2mm x 2mm)

[0439] Next, a hole injection layer 111 is formed on electrode 101, consisting of β-TNB and p-dopant. The weight ratio (β-TNB:p-dopant) is set to 1:0.01, and the thickness is 6 Co-deposited to achieve a wavelength of 0 nm.

[0440] Next, PCBBiF is used as a hole transport layer 112 on the hole injection layer 111, with a thickness of z1nm. The deposition was carried out in such a manner. Note that the value of z1 differs for each light-emitting element, and for each light-emitting element... The values ​​of z1 are shown in Table 17.

[0441] Next, as the light-emitting layer 130(1) on the hole transport layer 112, 2mDBTBPDBq-II PCBBiF and Ir(dppm)2(acac) are used in a weight ratio (2mDBTBPD) Bq-II:PCBBiF:Ir(dppm)2(acac)) is 0.7:0.3:0. Co-deposited to achieve a 0.6 ratio and a thickness of 20 nm, followed by the emission layer 130(2 ) as weight ratio (2mDBTBPDBq-II:PCBBiF:Ir(dppm)2( The ratio of acac)) should be 0.8:0.2:0.06, and the thickness should be 20nm. Co-deposited on the above. In addition, in the light-emitting layer 130(1) and light-emitting layer 130(2), Ir(dp pm)2(acac) is a guest material that exhibits phosphorescence.

[0442] Next, on the light-emitting layer 130(2), a first electron transport layer 118(1) is made of 2 mDBTB. PDBq-II was co-deposited to a thickness of 20 nm. Subsequently, the first electron transport layer 1 18(1) has a second electron transport layer 118(2) made of 2,9-bis(naphthalene-2- (Iyl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) is applied to the membrane. The material was deposited to a thickness of 20 nm.

[0443] Next, on the second electron transport layer 118(2), lithium fluoride is added as an electron injection layer 119. LiF was deposited to a thickness of 1 nm.

[0444] Next, on the electron injection layer 119, an electrode 102 made of aluminum (Al) with a thickness of 20 It was formed to have a wavelength of 0 nm.

[0445] Next, the glove box is sealed using an organic EL sealing material in a nitrogen atmosphere. By fixing the glass substrate for this purpose to a glass substrate on which an organic material has been formed, comparative light-emitting element 5 1 to 54 comparative light-emitting elements were sealed. Specifically, the organic material was formed on a glass substrate. A sealing material is applied around the equipment material, and the substrate and the glass substrate for sealing are bonded together, creating a wave The length is 6 J / cm² of ultraviolet light at 365 nm. 2 The material was irradiated and then heat-treated at 80°C for 1 hour. Comparative light-emitting elements 51 to 54 were obtained accordingly.

[0446] <<Fabrication of comparative light-emitting elements 55 to 58 and light-emitting elements 59 to 66>> The manufacturing process for comparative light-emitting elements 55 to 58 and light-emitting elements 59 to 66 is as follows: The manufacturing process of the above comparative light-emitting elements 51 to 54 and the manufacturing process of the hole injection layer 111 Except for the above, the other processes were carried out in the same manner as for the comparative light-emitting elements 51 to 54. Element structure The details are shown in Tables 16 and 17, so the details of the manufacturing method are omitted.

[0447] <Characteristics of light-emitting elements> Next, the comparison light-emitting elements 51 to 58 and 59 to light-emitting elements fabricated above are used. The characteristics of element 66 were measured. The measurement was performed in the same manner as in Example 1. 1000 cd / m 2 Nearby The characteristics of each element are shown in Table 19. The external quantum efficiencies shown in Table 19 are before field-of-view correction. This demonstrates the external quantum efficiency.

[0448] [Table 19]

[0449] Based on the above results, the comparative light-emitting elements 51 to 58 and the light-emitting elements fabricated in this embodiment Regardless of the structure of the hole injection layer 111, the light-emitting elements 59 to 66 exhibit good driving voltage and light-emitting effect. It can be seen that it is showing a rate.

[0450] <Relationship between the refractive index of the hole injection layer 111 and the external quantum efficiency> Figure 32 shows the values ​​for each element shown in Table 19, and the organic material used in each hole injection layer 111 Next, the relationship between chromaticity y and external quantum efficiency is shown. In Figure 32, the data for the "β-TNB" curve is The values ​​of the comparative light-emitting elements 51 to 54 are used in the data for the "NPB" curve, and the comparative light emission values ​​are used in the data. The values ​​of element 55 to the comparative light-emitting element 58 are included in the data for the "BPAFLP" curve. The values ​​of 9 to 62 light-emitting elements are included in the data of the "TAPC" curve, and the values ​​of 63 to 62 light-emitting elements are included in the data of the "TAPC" curve. The value 66 was used for each.

[0451] Table 18 shows that when β-TNB and NPB are used in the hole injection layer 111, the hole injection layer 111 The refractive index is high, exceeding 1.75, but when using BPAFLP and TAPC... Therefore, the refractive index of the hole injection layer 111 is low, at 1.75 or less. As shown in Figure 32, for example, Comparing the external quantum efficiency of each light-emitting element around a y-chromaticity of 0.435, hole injection with a low refractive index is observed. It was found that the light-emitting element with layer 111 has a higher external quantum efficiency. At the same chromaticity, a light-emitting element having a hole injection layer 111 with a lower refractive index emits better light. It was found to have efficiency. This is because the attenuation of light due to evanescent mode is reduced. This is because the light extraction efficiency has improved.

[0452] (Reference example 1) This reference example describes the synthesis method of Ir(pbi-diBuCNp)3 used in Example 1. I will explain.

[0453] <Step 1: Synthesis of 4-amino-3,5-diisobutylbenzonitrile> 4-amino-3,5-dichlorobenzonitrile 52g (280 mmol), isobutyl nitrile 125g of phosphate (1226 mmol), 260g of tripotassium phosphate (1226 mmol) , 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (S-phos ) 5.4g (13.1 mmol), add 1500mL of toluene to a 3000mL three-necked flask. Add the mixture, purge the flask with nitrogen, stir the mixture under reduced pressure, and degas the mixture. After degassing, Tris(dibenzylideneacetone)dipalladium(0)4.8g(5.2m Add (mol) and stir at 130°C for 12 hours under a nitrogen stream. Add Tolué to the resulting reaction solution. Adding n, Celite (Wako Pure Chemical Industries, Ltd., catalog number: 531-16855) / Florizil (Wako Pure Chemical Industries, Ltd., Catalog Number: 540-00135) / Al Oxide The filtrate was filtered by suction through a filtration aid consisting of layers of titanium. The resulting filtrate was concentrated and then processed into an oily liquid. A substance was obtained. The obtained oily substance was purified by silica column chromatography. (Laser) Toluene was used. The resulting fraction was concentrated to obtain 61 g of a yellow oily substance, yielding a yield of 100 g. It was obtained at 95%. The yellow oily substance obtained by nuclear magnetic resonance (NMR) was 4-amino-3,5 -Confirmed that it is diisobutylbenzonitrile. The synthesis scheme for Step 1 is shown below. This is shown in equation (a-1).

[0454] [ka]

[0455] Step 2; 4-[N-(2-nitrophenyl)amino]-3,5-diisobutylbene Synthesis of zonitrile > 30g of 4-amino-3,5-diisobutylbenzonitrile synthesized in Step 1 (131 mmol), cesium carbonate 86g (263 mmol), dimethyl sulfoxide (DMSO) 380 mL, 19 g (131 mmol) of 2-fluoronitrobenzene mixed in 1000 mL. The mixture was placed in a mouthed flask and stirred at 120°C under a nitrogen stream for 20 hours. The reaction solution after the specified time had elapsed was then measured. The liquid was extracted with chloroform to obtain the crude product. The obtained crude product was then analyzed using a silica column. The sample was purified by chromatography. A hexane:ethyl acetate mixture in a 7:1 ratio was used as the developing solvent. The obtained fraction was concentrated to obtain an orange solid. Hexane was added to the obtained solid. The mixture was then filtered by suction to obtain 16 g of a yellow solid in 35% yield. Nuclear magnetic resonance (NMR) spectroscopy was performed. The resulting yellow solid is 4-[N-(2-nitrophenyl)amino]-3,5-diisobutyl It was confirmed to be benzonitrile. The synthesis scheme for Step 2 is given by the following formula (a-2). show.

[0456] [ka]

[0457] Step 3; 4-[N-(2-aminophenyl)amino]-3,5-diisobutylbene Synthesis of zonitrile > The 4-[N-(2-nitrophenyl)amino]-3,5-diisobutyric acid synthesized in Step 2 21g (60.0 mmol) of benzonitrile, 11mL (0.6 mol) of water, ethanol 780 mL of the solution was placed in a 2000 mL three-necked flask and stirred. In this mixture, tin chloride (I) was added. I) 57 g (0.3 mol) was added and stirred at 80°C for 7.5 hours under a nitrogen stream. After some time has passed, pour this mixture into 400 mL of 2 M sodium hydroxide aqueous solution and leave at room temperature for 16 hours. The mixture was stirred. The precipitated material was removed by suction filtration, and then washed with chloroform. A filtrate was obtained. The obtained filtrate was extracted with chloroform. Subsequently, the extracted solution was... The solution was concentrated to obtain 20 g of a white solid in 100% yield. The result was obtained by nuclear magnetic resonance (NMR) spectroscopy. The white solid was 4-[N-(2-aminophenyl)amino]-3,5-diisobutylbenzo It was confirmed to be a nitrile. The synthesis scheme for Step 3 is shown in formula (a-3) below.

[0458] [ka]

[0459] <Step 4; 1-(4-cyano-2,6-diisobutylphenyl)-2-phenyl-1 Synthesis of H-benzimidazole (abbreviation: Hpbi-diBuCNp) The 4-[N-(2-aminophenyl)amino]-3,5-diisobutyric acid synthesized in Step 3 20g (60.0 mmol) of benzonitrile, 200mL of acetonitrile, benzalkonium Place 6.4g (60.0 mmol) of dehyde into a 1000mL round-bottom flask and heat at 100°C. The mixture was stirred for a certain amount of time. 100 mg (0.60 mmol) of iron(III) chloride was added to this mixture. The mixture was stirred at 100°C for 24 hours. After the predetermined time, the reaction solution was extracted with chloroform. This was done to obtain an oily substance. Toluene was added to the obtained oily substance, and Celite / Fluorizyl / Acid The filtrate was filtered by suction through a filtration aid consisting of layers of aluminum oxide. The resulting filtrate was concentrated. An oily substance was obtained. The obtained oily substance was purified by silica column chromatography. Toluene was used as the open solvent. The resulting fraction was concentrated to obtain a solid. When the body was recrystallized with ethyl acetate / hexane, 4.3 g of the target product, a white solid, was obtained in yield. It was obtained at 18%. The white solid obtained by nuclear magnetic resonance (NMR) was 1-(4-cyano-2 ,6-diisobutylphenyl)-2-phenyl-1H-benzoimidazole (abbreviation: Hp We confirmed that it is bi-diBuCNp. The synthesis scheme in step 4 is given by the following equation (a As shown in -4).

[0460] [ka]

[0461] <Step 5; Tris{2-[1-(4-cyano-2,6-diisobutylphenyl)-1 H-benzoimidazole-2-yl-κN 3 ]phenyl-κC}iridium(III)( Abbreviation: Synthesis of Ir(pbi-diBuCNp)3) The 1-(4-cyano-2,6-diisobutylphenyl)-2-phenyl synthesized in Step 4 1H-benzimidazole (abbreviation: Hpbi-diBuCNp) 1.8g (4.4mg) (mol), Tris(acetylacetonate)iridium(III) 0.43g (0.88mg) The mol was placed in a reaction vessel fitted with a three-way stopcock and heated at 250°C for 39 hours. Toluene was added to the reaction mixture, and insoluble matter was removed. The resulting filtrate was concentrated, and the solid was extracted. The obtained solid was purified by silica column chromatography (neutral silica). Toluene was used as the developing solvent. The resulting fraction was concentrated to obtain a solid. The resulting solid was recrystallized with ethyl acetate / hexane, yielding 0.26 g of a yellow solid in 21% yield. The synthesis scheme is shown in equation (a-5) below.

[0462] [ka]

[0463] The protons of the yellow solid obtained above ( 1 H) was measured by nuclear magnetic resonance (NMR). From the measurement results, in this reference example, Ir(pbi-diBuCNp)3(fac and me It was found that a mixture of the r-isomer was obtained. 1 From H-NMR, the fac isomer and, It was confirmed to be a mixture of mer isomers. The isomer ratio is fac isomer:mer isomer = 3:2 It was found to be that proportion. [Explanation of symbols]

[0464] 10: Substrate, 11: Electrode, 12: Electrode, 15: Substrate, 20: Organic semiconductor layer, 30: Carrier A: Transport layer, 40: Functional layer, 50: Electronic device, 100: EL layer, 101: Electrode, 102 : Electrode, 106: Light-emitting unit, 108: Light-emitting unit, 110: Light-emitting unit, 111 : Hole injection layer, 112: Hole transport layer, 113: Electron transport layer, 114: Electron injection layer, 115 : Charge generation layer, 116: Hole injection layer, 117: Hole transport layer, 118: Electron transport layer, 119 : Electron injection layer, 120: Emitting layer, 121: Guest material, 122: Host material, 130: Emitting layer Photolayer, 131: Guest material, 131_1: Organic compound, 131_2: Organic compound, 132 :Host material, 134:Emitting region, 140:Emitting layer, 141:Guest material, 142:Host Material, 142_1: Organic compound, 142_2: Organic compound, 150: Light-emitting element, 170 : Light-emitting layer, 200: Substrate, 250: Light-emitting element, 252: Light-emitting element, 601: Source-side drive Circuit, 602: Pixel section, 603: Gate-side drive circuit, 604: Encapsulation substrate, 605: Seal Materials, 607: Space, 608: Wiring, 610: Element board, 611: Switching TFT, 612: TFT for current control, 613: Electrode, 614: Insulator, 616: EL layer, 617: Electrode, 618: light-emitting element, 623: n-channel TFT, 624: p-channel TFT, 900: Portable information terminal, 901: Housing, 902: Housing, 903: Display unit, 905: Hinge Part, 910: Portable information terminal, 911: Housing, 912: Display unit, 913: Operation buttons, 91 4: External connection port, 915: Speaker, 916: Microphone, 917: Camera, 920: Camera Camera, 921: Casing, 922: Display unit, 923: Operation buttons, 924: Shutter button , 926: lens, 1001: substrate, 1002: underlayer insulating film, 1003: gate insulating film, 1006: Gate gate, 1007: Gate gate, 1008: Gate gate, 1020: Interlayer Insulating film, 1021: Interlayer insulating film, 1022: Electrode, 1024B: Electrode, 1024G: Electrode , 1024R: Electrode, 1024W: Electrode, 1025B: Lower electrode, 1025G: Lower electrode , 1025R: lower electrode, 1025W: lower electrode, 1026: partition wall, 1028: EL layer, 1029: Electrode, 1031: Encapsulation substrate, 1032: Sealing material, 1033: Base material, 1034 B: Colored layer, 1034G: Colored layer, 1034R: Colored layer, 1036: Overcoat layer, 1037: Interlayer insulating film, 1040: Pixel section, 1041: Driving circuit section, 1042: Peripheral section, 3054: Display unit, 3500: Multifunction terminal, 3502: Enclosure, 3504: Display unit, 350 6: Camera, 3508: Lighting, 3600: Light, 3602: Enclosure, 3608: Lighting, 3 610: Speaker, 8501: Lighting device, 8502: Lighting device, 8503: Lighting device, 8 504: Lighting device, 9000: Enclosure, 9001: Display unit, 9003: Speaker, 9005 : Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 90 55: Hinge, 9200: Mobile information terminal, 9201: Mobile information terminal, 9202: Mobile information terminal

Claims

1. It comprises a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer. Between the first electrode and the second electrode, there is a first layer, a second layer, and the light-emitting layer, The above first layer is located between the above first electrode and the light-emitting layer. The first layer comprises a first organic compound having a pyrrole skeleton and a tetraarylmethane skeleton. The second layer is located between the first layer and the light-emitting layer. The second layer comprises a second organic compound having a pyrrole skeleton. The parametric refractive index of the first layer is lower than that of the second layer. A light-emitting device wherein the paraoptic refractive index of the second layer is lower than that of the light-emitting layer.

2. It comprises a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer. Between the first electrode and the second electrode, there is a first layer, a second layer, and the light-emitting layer, The above first layer is located between the above first electrode and the light-emitting layer. The first layer comprises a first organic compound having a carbazole skeleton and a tetraarylmethane skeleton, The second layer is located between the first layer and the light-emitting layer. The second layer comprises a second organic compound having a carbazole skeleton, The parametric refractive index of the first layer is lower than that of the second layer. A light-emitting device wherein the paraoptic refractive index of the second layer is lower than that of the light-emitting layer.

3. It comprises a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer. Between the first electrode and the second electrode, there is a first layer, a second layer, and the light-emitting layer, The first layer described above is located between the first electrode described above and the light-emitting layer, The first layer comprises a first organic compound having a pyrrole skeleton and a tetraarylmethane skeleton, and a first substance having electron-accepting properties. The second layer is located between the first layer and the light-emitting layer. The second layer comprises a second organic compound having a pyrrole skeleton. The parametric refractive index of the first layer is lower than that of the second layer. A light-emitting device wherein the paraoptic refractive index of the second layer is lower than that of the light-emitting layer.

4. It comprises a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer. Between the first electrode and the second electrode, there is a first layer, a second layer, and the light-emitting layer, The first layer described above is located between the first electrode described above and the light-emitting layer, The first layer comprises a first organic compound having a carbazole skeleton and a tetraarylmethane skeleton, and a first substance having electron-accepting properties. The second layer is located between the first layer and the light-emitting layer. The second layer comprises a second organic compound having a carbazole skeleton, The parametric refractive index of the first layer is lower than that of the second layer. A light-emitting device wherein the paraoptic refractive index of the second layer is lower than that of the light-emitting layer.

5. It comprises a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer. Between the first electrode and the second electrode, there is a first layer, a second layer, and the light-emitting layer, The first layer described above is located between the first electrode described above and the light-emitting layer, The first layer comprises a first organic compound having a pyrrole skeleton and a tetraarylmethane skeleton, and a first substance having at least one halogen group and a cyano group. The second layer is located between the first layer and the light-emitting layer. The second layer comprises a second organic compound having a pyrrole skeleton. The parametric refractive index of the first layer is lower than that of the second layer. A light-emitting device wherein the paraoptic refractive index of the second layer is lower than that of the light-emitting layer.

6. It comprises a first electrode, a second electrode, a first layer, a second layer, and a light-emitting layer. Between the first electrode and the second electrode, there is a first layer, a second layer, and the light-emitting layer, The first layer described above is located between the first electrode described above and the light-emitting layer, The first layer comprises a first organic compound having a carbazole skeleton and a tetraarylmethane skeleton, and a first substance having at least one halogen group and a cyano group. The second layer is located between the first layer and the light-emitting layer. The second layer comprises a second organic compound having a carbazole skeleton, The parametric refractive index of the first layer is lower than that of the second layer. A light-emitting device wherein the paraoptic refractive index of the second layer is lower than that of the light-emitting layer.

7. In any one of claims 1 to 6, A light-emitting device in which the first organic compound and the second organic compound are different compounds.

8. In any one of claims 1 to 7, The light-emitting device wherein the aforementioned ordinary refractive index is the ordinary refractive index at a wavelength of 532 nm.

9. In any one of claims 1 to 7, The light-emitting device wherein the aforementioned ordinary refractive index is the ordinary refractive index at a wavelength of 633 nm.

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