Light-emitting element, display device, electronic device and lighting device

Abstract

To provide a light-emitting device that has high luminous efficacy and high reliability.SOLUTION: A light-emitting device has a luminous layer including a first organic compound, a second organic compound, and a guest material. The first organic compound has a nitrogen-containing six-membered complex aromatic skeleton. In the luminous layer, the content of an organic component including a nitrogen-containing five-membered heterocyclic skeleton having a NH group, a secondary amine skeleton, or a primary amine skeleton is 0.03 or less in terms of weight ratio with respect to the first organic compound, and 0.01 or less in terms of weight ratio with respect to the second organic compound.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] One embodiment of the present invention is a light-emitting element, or a display device, an electronic device, and a lighting device each having the light-emitting element. Regarding the lighting device.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one aspect of the present invention relates to an article, a method, or a manufacturing method. is a process, machine, manufacture, or composition of matter. Therefore, the technical field of one embodiment of the present invention disclosed in this specification more specifically relates to Examples of the semiconductor device include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, and the like. Examples include devices, methods for driving them, and methods for manufacturing them. . [Background technology]

[0003] In recent years, electroluminescence (EL) The basic structure of these light-emitting devices is as follows: The device has a structure in which a layer containing a light-emitting substance (EL layer) is sandwiched between a pair of electrodes. By applying a voltage between them, light is emitted from the luminescent material.

[0004] Since the above-mentioned light-emitting element is a self-luminous type, a display device using it has excellent visibility and It has the advantage of not requiring a light source and consuming little power. It also has the advantage of high response speed.

[0005] An organic compound is used as the light-emitting substance, and an EL layer containing the light-emitting substance is provided between a pair of electrodes. In the case of a light-emitting element (for example, an organic EL element), a voltage is applied between a pair of electrodes. Electrons are injected from the cathode and holes are injected from the anode into the EL layer, causing a current to flow. The injected electrons and holes are then recombined to excite the light-emitting organic compound. The excited luminescent organic compound is then in an excited state, and light can be emitted from the excited luminescent organic compound.

[0006] The light emitted by a light-emitting organic compound is light that is specific to that organic compound. Light-emitting elements that emit various types of light by using various organic compounds as light-emitting substances can be obtained.

[0007] One of the important properties of such light emitting devices is efficiency and reliability. It is important to reduce impurities that can reduce the efficiency and reliability of the device. In Patent Document 1, attention is paid to halogen compounds in an EL layer containing organic compounds, and the concentration of the halogen compounds is kept constant. It is disclosed that a highly reliable light-emitting element can be obtained by the following. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 00 / 41443 Summary of the Invention [Problem to be solved by the invention]

[0009] While there are impurities that cause a decrease in the efficiency and reliability of light-emitting devices, There are also impurities that do not affect the characteristics of the light-emitting element. It is important to identify the type of impurity. Because the content is so small, it is often difficult to identify impurities. The mechanism that degrades device performance is largely unknown.

[0010] Therefore, an object of one embodiment of the present invention is to provide a highly reliable light-emitting element. Another object of one embodiment of the present invention is to provide a light-emitting element with high emission efficiency. Another embodiment of the present invention is to provide a light-emitting element with reduced power consumption. Another object of one embodiment of the present invention is to provide a novel light-emitting element. Another object of one embodiment of the present invention is to provide a novel light-emitting device. Another object of one embodiment of the present invention is to provide a novel display device.

[0011] Note that the above description of the object does not preclude the existence of other objects. It is not necessary to solve all of these problems. Problems other than those mentioned above can be solved by the description of the specification, etc. It is obvious from the description of the specification, etc. that other problems can be extracted. do. [Means for solving the problem]

[0012] One embodiment of the present invention is a light-emitting element having a light-emitting layer, in which the light-emitting layer contains a first organic compound and and a guest material, wherein the first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton and is luminescent. In the layer, a nitrogen-containing five-membered heterocyclic skeleton having an NH group, a secondary amine skeleton having an NH group, or or a primary amine skeleton having an NH group, the content of the organic compound containing the first organic compound is The weight ratio of the light emitting element to the total weight of the light emitting element is 0.03 or less.

[0013] Another embodiment of the present invention is a light-emitting element having a light-emitting layer, in which the light-emitting layer includes a first The first organic compound has a pyridine skeleton, a diazine skeleton, and a guest material. or a triazine skeleton, and in the light-emitting layer, a pillow compound having an NH group imidazole skeleton with NH group, triazole skeleton with NH group, or an aromatic amine skeleton having an NH group. The content of the second organic compound is 0.03 or less in terms of a weight ratio relative to the first organic compound.

[0014] Another embodiment of the present invention is a light-emitting element having a light-emitting layer, in which the light-emitting layer includes a first conductive layer. The first organic compound is a nitrogen-containing organic compound, a second organic compound, and a guest material. The second organic compound has a six-membered heteroaromatic skeleton, and the second organic compound has a nitrogen-containing five-membered heterocyclic skeleton or a tertiary amine. a nitrogen-containing five-membered heterocyclic skeleton having an NH group in the light-emitting layer, An organic compound containing a secondary amine skeleton having an NH group or a primary amine skeleton having an NH group The light-emitting device has a weight ratio of the content of the material to the second organic compound of 0.01 or less.

[0015] Another embodiment of the present invention is a light-emitting element having a light-emitting layer, in which the light-emitting layer includes a first conductive layer. The first organic compound is a pyridine, a second organic compound is a guest material, and the second organic compound is a pyridine. a second organic compound having at least one of an azine skeleton, a diazine skeleton, or a triazine skeleton; The compound has a pyrrole skeleton, an imidazole skeleton, a triazole skeleton, a tetrazole skeleton, or an aromatic a pyrrole skeleton having an NH group in the light-emitting layer; Imidazole skeleton with NH group, triazole skeleton with NH group, tetrazole skeleton with NH group The content of organic compounds containing a trazole skeleton or an aromatic amine skeleton having an NH group is The weight ratio of the first organic compound to the second organic compound is 0.01 or less.

[0016] In each of the above structures, the NH bond is released from the excited state of the organic compound having the NH group. The effect of one embodiment of the present invention is that the activation energy required for dissociation is 0.3 eV or less. In addition, the stabilization energy of the NH bond dissociation in the NH group is 0 eV. When the ratio is less than this, the effect of one embodiment of the present invention is large.

[0017] In each of the above structures, the light-emitting layer may include a nitrogen-containing five-membered compound in which the nitrogen atom has an unpaired electron. of organic compounds containing a heterocyclic skeleton or an aromatic amine skeleton in which the nitrogen atom has an unpaired electron The content is preferably 0.03 or less in weight ratio to the first organic compound. The content of the organic compound in which a hydrogen atom is further bonded to the first organic compound in the optical layer is The weight ratio of the first organic compound to the second organic compound is preferably 0.03 or less.

[0018] In each of the above structures, the light-emitting layer may include a nitrogen-containing five-membered compound in which the nitrogen atom has an unpaired electron. of organic compounds containing a heterocyclic skeleton or an aromatic amine skeleton in which the nitrogen atom has an unpaired electron The content is preferably 0.01 or less in terms of weight ratio to the second organic compound. The content of the organic compound in which a hydrogen atom is further bonded to the first organic compound in the optical layer is The weight ratio of the second organic compound to the second organic compound is preferably 0.01 or less.

[0019] In each of the above structures, the guest material converts triplet excitation energy into luminescence. It is preferable that the guest material has a function of being able to do this. In addition, it is preferable that the guest material contains iridium. stomach.

[0020] Another embodiment of the present invention is a light-emitting element having any of the above structures, a color filter or a transistor, and a light-emitting element. and at least one of the plurality of transistors. The electronic device has a display device and at least one of a housing and a touch sensor. Another aspect of the present invention is a light-emitting element having any of the above structures, a housing, or a touch sensor. Another embodiment of the present invention is a lighting device including a light-emitting element. Therefore, the term "light emitting device" as used herein includes not only the electronic device but also the electronic device having the light emitting device. An optical device refers to an image display device or a light source (including a lighting device). Connectors, such as FPC (Flexible Printed Circuit), Display module with TCP (Tape Carrier Package) attached , a display module with a printed wiring board at the end of the TCP, or a light-emitting element with COG ( A display module in which an IC (integrated circuit) is directly mounted using the Chip On Glass method. The rule is also an aspect of the present invention. [Effects of the Invention]

[0021] According to one embodiment of the present invention, a highly reliable light-emitting element can be provided. A light-emitting element with high efficiency can be provided. Alternatively, according to one embodiment of the present invention, a novel light-emitting element having reduced According to one embodiment of the present invention, a novel light-emitting device can be provided. According to one embodiment of the present invention, a novel display device can be provided. can.

[0022] The description of these effects does not preclude the existence of other effects. It is not necessary to have all of these effects. Effects other than these may be included in the description. It is obvious from the description of the specification, drawings, claims, etc. From this, it is possible to extract other effects. [Brief explanation of the drawings]

[0023] [Figure 1] 1A and 1B are schematic cross-sectional views of a light-emitting element according to one embodiment of the present invention. [Figure 2] 1A to 1C illustrate a reaction according to one embodiment of the present invention. [Figure 3] 1A to 1C illustrate a reaction according to one embodiment of the present invention. [Figure 4] 1A to 1C illustrate a reaction according to one embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating the correlation between the LUMO level and energy according to one embodiment of the present invention. [Figure 6] 1A and 1B are schematic cross-sectional views of light-emitting elements according to embodiments of the present invention and diagrams illustrating correlations between energy levels of light-emitting layers. [Figure 7] 1A and 1B are schematic cross-sectional views of light-emitting elements according to embodiments of the present invention and diagrams illustrating correlations between energy levels of light-emitting layers. [Figure 8] 1A and 1B are schematic cross-sectional views of light-emitting elements according to embodiments of the present invention and diagrams illustrating correlations between energy levels of light-emitting layers. [Figure 9] 1A and 1B are schematic cross-sectional views of a light-emitting element according to one embodiment of the present invention. [Figure 10] 1A and 1B are schematic cross-sectional views of a light-emitting element according to one embodiment of the present invention. [Figure 11] 1A to 1C are schematic cross-sectional views illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 12] 1A to 1C are schematic cross-sectional views illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 13] 1A and 1B are a top view and a cross-sectional view schematic diagram illustrating a display device of one embodiment of the present invention. [Figure 14]1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 15] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 16] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 17] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 18] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 19] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 20] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 21] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 22] 1A to 1C are cross-sectional views illustrating a method for producing an EL layer. [Figure 23] FIG. 1 is a conceptual diagram illustrating a droplet ejection device. [Figure 24] 1A and 1B are a block diagram and a circuit diagram illustrating a display device of one embodiment of the present invention. [Figure 25] FIG. 1 is a circuit diagram illustrating a pixel circuit of a display device according to one embodiment of the present invention. [Figure 26] FIG. 1 is a circuit diagram illustrating a pixel circuit of a display device according to one embodiment of the present invention. [Figure 27] FIG. 1 is a perspective view illustrating an example of a touch panel of one embodiment of the present invention. [Figure 28] 1A and 1B are cross-sectional views illustrating examples of a display device and a touch sensor according to one embodiment of the present invention. [Figure 29] FIG. 1 is a cross-sectional view illustrating an example of a touch panel of one embodiment of the present invention. [Figure 30] 1A and 1B are a block diagram and a timing chart of a touch sensor according to one embodiment of the present invention. [Figure 31] FIG. 1 is a circuit diagram of a touch sensor according to one embodiment of the present invention. [Figure 32] FIG. 1 is a perspective view illustrating a display module of one embodiment of the present invention. [Figure 33] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 34]1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 35] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 36] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 37] FIG. 1 is a perspective view illustrating a display device according to one embodiment of the present invention. [Figure 38] 1A and 1B are a perspective view and a cross-sectional view illustrating a light-emitting device according to one embodiment of the present invention. [Figure 39] FIG. 1 is a cross-sectional view illustrating a light-emitting device according to one embodiment of the present invention. [Figure 40] 1A to 1C illustrate a lighting device and an electronic device according to one embodiment of the present invention. [Figure 41] 1A to 1C illustrate a lighting device according to one embodiment of the present invention. [Figure 42] 1A and 1B are cross-sectional views illustrating a light-emitting element according to an embodiment. [Figure 43] FIG. 10 is a graph showing luminance-current density characteristics of a light-emitting element according to an example. [Figure 44] FIG. 10 is a graph showing luminance-voltage characteristics of a light-emitting element according to an example. [Figure 45] FIG. 10 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 46] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 47] FIG. 10 is a graph showing power efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Figure 48] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 49] 1A and 1B are diagrams illustrating absorption spectra and emission spectra of compounds according to an example. [Figure 50] FIG. 2 is a diagram illustrating the emission spectrum of a compound according to an example. [Figure 51] 10A and 10B are graphs illustrating emission spectra of light-emitting elements according to Examples. [Figure 52] 10A and 10B are graphs illustrating the correlation between the external quantum efficiency and the emission spectrum intensity of a light-emitting element according to an example. [Figure 53]10A to 10C are diagrams illustrating the results of a reliability test on a light-emitting element according to an example. [Figure 54] 10A and 10B are graphs illustrating the correlation between the weight ratio of impurities and reliability of a light-emitting element according to an example. [Figure 55] FIG. 10 is a graph showing luminance-current density characteristics of a light-emitting element according to an example. [Figure 56] FIG. 10 is a graph showing luminance-voltage characteristics of a light-emitting element according to an example. [Figure 57] FIG. 10 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 58] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 59] FIG. 10 is a graph showing power efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Figure 60] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 61] FIG. 10 is a diagram illustrating the emission spectrum of a thin film according to an example. [Figure 62] FIG. 10 is a diagram illustrating the emission spectrum of a thin film according to an example. [Figure 63] FIG. 10 is a diagram illustrating the emission spectrum of a thin film according to an example. [Figure 64] FIG. 10 is a diagram illustrating the measurement results of the luminescence quantum yield of a thin film according to an example. [Figure 65] FIG. 10 is a diagram illustrating the measurement results of the luminescence quantum yield of a thin film according to an example. [Figure 66] FIG. 10 is a diagram illustrating the measurement results of the luminescence quantum yield of a thin film according to an example. [Figure 67] FIG. 10 is a diagram illustrating transient fluorescence characteristics of a thin film according to an embodiment. [Figure 68] FIG. 10 is a diagram illustrating transient fluorescence characteristics of a thin film according to an embodiment. [Figure 69] FIG. 10 is a diagram illustrating transient fluorescence characteristics of a thin film according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the above description, and the embodiments and details thereof may be modified without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the embodiments described below. The terms and conditions of the present invention are not to be construed as being limited to the content.

[0025] In addition, the position, size, range, etc. of each component shown in the drawings etc. are not necessarily shown in order to facilitate understanding. It may not represent the actual position, size, range, etc. Therefore, the disclosed invention The position, size, range, etc. are not necessarily limited to those disclosed in the drawings, etc.

[0026] In addition, in this specification, ordinal numbers such as 1st, 2nd, etc. are used for convenience, In some cases, the order of processes or layers may not be indicated. For example, "first" may be replaced with "second" or " can be appropriately replaced with "third" etc. The ordinal numbers used to identify an aspect of the present invention may not match. be.

[0027] In addition, in this specification and the like, when explaining the configuration of the invention using drawings, the same The reference numerals may be commonly used even among different drawings.

[0028] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the term "conductive layer" can be changed to the term "conductive film." Alternatively, for example, the term "insulating film" may be changed to "insulating layer" It may be possible to change the term to

[0029] In this specification and the like, the singlet excited state (S * ) is a single atom with excitation energy The S1 level is the lowest singlet excited energy level. It is the lowest excited energy level of the singlet excited state (S1 state). Singlet excited state (T * ) is a triplet state with excitation energy. The level is the lowest triplet excited energy level, and the lowest triplet excited state (T In this specification, the term "singlet excitation" is used to refer to the excitation energy level of a singlet electron. Even when written as the singlet excited state and singlet excited energy level, the S1 state and S1 Also, it is written as triplet excited state and triplet excited energy level. Even if the T1 state is not present, it may represent a T1 state and T1 level.

[0030] In this specification and the like, a fluorescent compound refers to a compound that relaxes from a singlet excited state to a ground state. On the other hand, phosphorescent compounds are substances that emit light in the visible light region when they are in a triplet excited state. When the material relaxes from the nucleus to the ground state, it emits light in the visible light region at room temperature. A phosphorescent compound is a substance that can convert triplet excitation energy into visible light. .

[0031] The phosphorescence energy or triplet excitation energy is the shortest wavelength side of the phosphorescence emission. It can be derived from the wavelength of the emission peak (including the shoulder) or the onset. The phosphorescence is observed by time-resolved photoluminescence in a low-temperature (e.g., 10 K) environment. The emission energy of thermally activated delayed fluorescence is , the shortest wavelength emission peak (including shoulder) or rising edge of thermally activated delayed fluorescence can be derived from the wavelength of

[0032] In this specification and the like, room temperature refers to a temperature between 0°C and 40°C.

[0033] In this specification, the blue wavelength region refers to wavelengths of 400 nm or more and less than 500 nm. blue emission has at least one emission spectrum peak in this region. The green wavelength range is the wavelength range of 500 nm or more and less than 580 nm. Green emission is emission having at least one emission spectrum peak in this region. The red wavelength range is the wavelength range between 580 nm and 680 nm. The emission is an emission having at least one emission spectrum peak in the region.

[0034] (Embodiment 1) In this embodiment, a light-emitting element of one embodiment of the present invention will be described below with reference to FIGS. Reveal.

[0035] <Configuration example of light-emitting element> First, the structure of a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. This is explained below.

[0036] FIG. 1A is a schematic cross-sectional view of a light-emitting element 150 of one embodiment of the present invention.

[0037] The light emitting element 150 has a pair of electrodes (electrode 101 and electrode 102), and The EL layer 100 has at least a light-emitting layer 130. .

[0038] The EL layer 100 shown in FIG. 1A includes a hole injection layer 111, a positive electrode layer 112, a positive electrode layer 113, a positive electrode layer 114, a positive electrode layer 115, a positive electrode layer 116, a positive electrode layer 117, a positive electrode layer 118, a positive electrode layer 119 ... It has functional layers such as a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119.

[0039] In this embodiment, of the pair of electrodes, electrode 101 is an anode, and electrode 1 Although the description will be given assuming that O2 is a cathode, the configuration of the light emitting element 150 is not limited to this. The electrode 101 is the cathode, the electrode 102 is the anode, and the layers between the electrodes are stacked in the reverse order. That is, from the anode side, the hole injection layer 111, the hole transport layer 112, and the light emitting layer 113 may be arranged in this order. The light-emitting layer 130, the electron transport layer 118, and the electron injection layer 119 may be stacked in this order. .

[0040] The configuration of the EL layer 100 is not limited to the configuration shown in FIG. 1(A). , a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119. Alternatively, the EL layer 100 may be configured to have either a hole or electron injection layer. Reduce the barrier, improve the transportability of holes or electrons, or inhibit the transportability of holes or electrons. or suppressing the quenching phenomenon caused by the electrode. The functional layers may each be a single layer or may be a laminate of multiple layers. It may be composed of

[0041] FIG. 1(B) is a cross-sectional view showing an example of the light-emitting layer 130 shown in FIG. 1(A). The light-emitting layer 130 shown in FIG.

[0042] The host material 131 may contain at least an organic compound 131_1. Compound 131_1 is preferably a compound having an electron transport function (having electron transport properties). Preferably, the compound has a nitrogen-containing six-membered heteroaromatic skeleton. The cations are preferred because they have high electron transport properties and are stable.

[0043] Preferably, the host material 131 further contains an organic compound 131_2. Compound 131_2 is preferably a compound having a function of transporting holes (having hole transport properties). Preferably, the compound has a nitrogen-containing five-membered heterocyclic skeleton or a tertiary amine skeleton. The five-membered heterocyclic skeleton or the tertiary amine skeleton is preferred because it has high hole transporting properties and is stable.

[0044] In addition, the combination of organic compound 131_1 and organic compound 131_2 has electron transport properties. When a compound having hole transport properties is used in combination with a compound having hole transport properties, the mixing ratio Specifically, the carrier balance can be easily controlled by using a material having electron transport properties. The compound having hole transporting properties: the compound having hole transporting properties is preferably in the range of 1:9 to 9:1 (weight ratio). In addition, by having this configuration, the carrier balance can be easily controlled. In addition, the carrier recombination region can be easily controlled.

[0045] Furthermore, a light-emitting organic compound may be used as the guest material 132. The organic compounds include substances that can emit fluorescence (hereinafter referred to as fluorescent compounds) or phosphorescence. It is preferable that the compound is a substance capable of emitting light (hereinafter also referred to as a phosphorescent compound). In this example, a fluorescent compound or a phosphorescent compound is used as the guest material 132. The guest material 132 is read as a fluorescent compound or a phosphorescent compound. You can change it.

[0046] In the light-emitting element 150 of one embodiment of the present invention, a pair of electrodes (electrode 101 and electrode 102) By applying a voltage between the cathode and the anode, electrons flow from the cathode and holes flow from the anode. The electrons and holes are then injected into the EL layer 100, causing a current to flow. By this, an exciton is formed. Since excitons have excitation energy, the material in which excitons are formed is This is the state.

[0047] When carriers recombine in the host material 131, excitons are generated, which The excited state (singlet excited state or triplet excited state) of the guest material 131 is formed. When 132 is a fluorescent compound, the S1 level of the host material 131 is converted to the S1 level of the guest material 132. The excitation energy is transferred to the level, forming a singlet excited state of the guest material 132. In addition, when the guest material 132 is a phosphorescent compound, the S1 level of the host material 131 or T1 level to the T1 level of the guest material 132, The triplet excited state of the guest material 132 is formed. When the guest material 132 in the ion-excited state decays to the ground state, light is emitted.

[0048] One of the characteristics required for the light emitting element 150 is high luminous efficiency. The decrease in luminous efficiency due to storage or long-term operation is small, that is, the device has a long life. In other words, it is required that the light emitting element has high luminous efficiency and high reliability. In order to have high reliability, the EL layer 100, especially the light-emitting layer 130, should contain no impurities. It is preferable to use small amounts of organic compounds.

[0049] In order to obtain organic compounds with low impurity content, it is necessary to increase the purity of the organic compounds. For example, impurities such as solvents used in synthesizing organic compounds and solvents are preferably removed. Organic compounds containing impurities or elements contained in raw materials used in the synthesis of organic compounds When a light-emitting element is fabricated using an organic compound containing the compound, the characteristics of the light-emitting element, for example, the driving voltage characteristics, In addition, for example, these impurities may cause deterioration in the properties, luminous efficiency characteristics, and reliability. Among substances, impurities containing halogen elements have a large impact, so their content is often low. Therefore, it is preferable that the organic compound used in the light-emitting element is one that has been subjected to sublimation purification to reduce the amount of impurities. Sublimation purification removes residual solvents from the synthesis and trace impurities (e.g. For example, separation of halides can be carried out.

[0050] However, due to reasons such as its molecular structure being similar to that of the organic compound used in the EL layer 100, There are impurities whose content is difficult to reduce, and even if the material is purified by sublimation, the impurities In addition, the organic compounds used to manufacture the light-emitting element may contain Even if the content of impurities is reduced, impurities may be mixed in during the manufacturing of the light-emitting element, and the light-emitting element may not be For example, impurities may be present in the material due to the decomposition of organic compounds during vacuum deposition. The generated substances may be mixed into the light emitting element as impurities. In the production method using a solvent, such as the ink jet method and the printing method, Impurities may be mixed into the light-emitting element. The substances generated by decomposition may be contained in the light-emitting element as impurities. Therefore, it is difficult to remove all impurities from the light emitting element.

[0051] On the other hand, there are also impurities that do not affect the characteristics of the light-emitting element even if they are contained in the EL layer 100. However, even such impurities can interact with other compounds to produce luminescent elements. The present inventors have found that substances that affect the properties of the child may be generated. The compound includes an organic compound having a nitrogen-containing five-membered heterocyclic skeleton or a secondary amine skeleton having an NH group, The characteristics of the light-emitting element are enhanced by the interaction with the organic compound having a nitrogen-containing six-membered heteroaromatic skeleton. Therefore, organic compounds with nitrogen-containing six-membered heteroaromatic skeletons are In a light-emitting device containing a compound, a nitrogen-containing five-membered heterocyclic skeleton having an NH group or a secondary amine The content of the organic compound having a skeleton is preferably small.

[0052] <Analysis of reaction mechanisms using quantum chemical calculations> <Calculation of the reaction mechanism between PCCH and 35DCzPPy> Here, an organic compound containing a nitrogen-containing five-membered heterocyclic skeleton having an NH group or a secondary amine skeleton and an organic compound having a nitrogen-containing six-membered heteroaromatic skeleton interact with each other to form a light-emitting element. The process by which impurities that affect the characteristics are generated will be explained below.

[0053] Quantum chemical calculations were used to analyze the above process. is shown below.

[0054] [ka]

[0055] The calculation shows that 3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol PCCH and 3,5-bis[3-(9H-carbazol-9-yl)phenyl ]pyridine (abbreviation: 35DCzPPy) interacts with the NH group of PCCH. The hydrogen atom that comes from the 35DCzPPy molecule moves to the PCC and 35DCzPPy- The hydrogen atom transfer reaction producing H was analyzed.

[0056] The calculation method is as follows. The quantum chemistry calculation program is Ga The calculation was performed using a high-performance computer (SGI, This was carried out using ICE X.

[0057] Initial, transition, and final states for hydrogen atom transfer reactions in the lowest excited triplet state. The stable structures of the two states were calculated using density functional theory (DFT). The total energy of DFT is calculated as potential energy, Exchange including interelectronic electrostatic energy, electron kinetic energy, and complex electron interactions In DFT, the single-electron potential is expressed as the electron density. The calculation is fast because the exchange-correlation interaction is approximated by a functional (a function of a function). Here, we use the mixed functional B3LYP to calculate the parameters related to the exchange and correlation energies. The weights of the meters were specified. The basis function used was 6-311G(d,p).

[0058] Reaction pathways and energies obtained from analysis of hydrogen atom transfer reactions in the lowest excited triplet state. The diagram is shown in Figure 2.

[0059] In Figure 2, the PCCH in the T1 state and the 35DCzPPy in the ground state (S0 state) are The activation energy of the reaction in which this hydrogen atom is transferred is used as the reference. The energy is very small, at 0.03 eV, and it can occur easily at room temperature. In the final state after the transfer, PCC and 35DCzPPy-H are in a radical state. The energy of the final state is lower than the energy of the initial state, and the reaction is exothermic. From this, it is possible to determine whether PCCH When 35DCzPPy and 35DCzPPy are in a molecular configuration that allows them to form hydrogen bonds, the migration of hydrogen atoms The kinetic reaction can occur rapidly. If the activation energy required for the dissociation of the NH bond is 0.3 eV or less, Hydrogen is easily dissociated in this state.

[0060] At this time, the radical state PCC and the radical state 35DCzPPy-H has higher energy than PCCH in the S0 state and 35DCzPPy in the S0 state Therefore, if there are no side reactions, the generated radical PCC and radical 35DCzPPy-H reversibly converts the original S0 state PCCH and the S0 state 35DCzP It can be thermally inactivated and reverted to Py.

[0061] Consider this reaction in a light-emitting device containing a guest material. The energy levels of the CC and radical states of 35DCzPPy-H) are determined by the excitation of the guest material. When the excited energy level of the 35CzPPy-H is lower than that of the 35CzPPy-H state, the guest In this case, the energy cannot be transferred to the material. The PCC and radical states (35DCzPPy-H) of the guest material and the excited state of the guest material are simultaneously generated. When the excited state guest material is synthesized, the radical state PCC and the radical state 35DC are formed. This causes the transfer of excitation energy to zPPy-H, which causes the guest material to emit light. Since this is not possible, the light emitting efficiency of the light emitting element decreases.

[0062] Next, the reactants (PCCH and 35DCzPPy) and products (P Ionization potential (Ip) and electron affinity (Ea) of CC and 35DCzPPy-H where the ionization potentials of PCCH and 35DCzPPy are the radical The electron affinity is calculated from the difference in total energy between the thione state and the singlet ground state. The total energy of the 35DCzPPy radical anion was calculated from the difference between the total energy of the 35DCzPPy radical anion and the total energy of the 35DCzPPy radical anion. The ionization potential of -H is calculated from the difference in total energy between the cation state and the radical state. The electron affinity was calculated from the difference in total energy between the radical state and the anion state. This state is assumed to be the driving state of the light-emitting device, that is, the state in which carriers are injected into the molecules. It's a calculation.

[0063] The ionization potential (IP) and electron affinity (E a) is shown in Table 1.

[0064] [Table 1]

[0065] The smaller the ionization potential, the easier it is for holes to enter the molecule, and the electron affinity The larger the value, the easier it is for an electron to enter a molecule. -H is most likely to accept electrons, and PCC is most likely to accept electrons.

[0066] Then, the radical PCC receives an electron and becomes an anion. When the 35DCzPPy-H in the cationic state receives a hole, the energy of the T1 level The energy of the T1 level of each compound is shown in Table 2. The energy of is the sum of the lowest excited triplet state (T1 state) and the singlet ground state (S0 state). It was calculated from the difference in energy.

[0067] [Table 2]

[0068] As shown in Table 2, the anionic state of PCC and the cationic state of 35DCzPPy-H The T1 levels were all low energy levels of 2 eV or less. A phosphorescent compound having a T1 level higher than at least one of the T1 levels of the In the light-emitting element having the above structure, triplet excitation of the host material 131 and the guest material 132 is The electromotive force is transferred to the anionic state of PCC or the cationic state of 35DCzPPy-H. The excitation energy of the host material 131 and the guest material 132 is deactivated. Cheap.

[0069] As mentioned above, in the coexistence of PCCH and 35DCzPPy, in the excited state, The hydrogen atom from the NH group of 35DCzPPy is transferred to 35DCzPPy. In this case, the excitation energy of the host material 131 is deactivated without being transferred to the guest material 132. In addition, compounds temporarily generated by hydrogen transfer reactions (PCC and 35D The T1 level in the charged states (cation and anion states) of CzPPy-H is Since the T level is in an energy-low level, the T level is The T1 level of the compound is likely to be lower than that of the compound, and the compound thus produced is not suitable for use as a light-emitting element 15. These generated PCC and 35DCzPPy-H can be quenching factors for 0. Irreversible reactions involving repeated excitation, oxidation, and reduction lead to even lower energy levels. Therefore, the driving of the light emitting element 150 The hydrogen transfer reaction that occurs due to the movement can cause a decrease in reliability. When layer 130 contains 35DCzPPy, the content of PCCH in light-emitting layer 130 is small. It is preferable that

[0070] In the above calculation, the PCCH in the T1 state and the 35D in the ground state (S0 state) The reaction was calculated with CzPPy as the initial state. H, and the ground state (S0 state) of 35DCzPPy. The S1 state is the T1 state. Because it is a higher energy excited state, PCCH in the S1 state and 35DC in the S0 state When reacting with zPPy, the initial state energy is higher, and PCCH Therefore, even in this case, the reaction between PC and 35DCzPPy is more likely to occur. The reaction of CH with 35DCzPPy results in the excitation energy of the host material 131 being guest. In some cases, hydrogen may be deactivated without being transferred to the hydrogen transfer reaction. S1 levels in the charged states (cationic and anionic states) of transiently generated compounds Since the S1 level is a low energy level, the S1 level is If the S1 level of the resulting compound is lower than the S1 level of the compound, the resulting compound will act as a quencher for the light-emitting device 150. In this case, the generated PCC and 35DCzPPy-H can be repeatedly excited and oxidized. , and by irreversible reactions accompanying reduction, to those with even lower energy levels Therefore, hydrogen transfer that proceeds when the light-emitting element 150 is driven may occur. The reaction may cause a decrease in reliability. Therefore, the guest material 132 is preferably a fluorescent compound. Even when a material such as 35DCzPPy is used, if the light-emitting layer 130 contains 35DCzPPy, It is preferable that the content of PCCH in 30 is low.

[0071] <Calculation of reactivity depending on the state of PCCH> Next, when the initial state of PCCH is not excited, the NH group of PCCH The stabilization energy of hydrogen atoms when they dissociate was calculated. Starting from CCH and 35DCzPPy, the hydrogen atoms derived from the NH group of PCCH are infinitely The final state is when the molecule dissociates and binds to 35DCzPPy, and the energy difference is stabilized. The calculation was performed as energy. The calculation method can be referred to above. The calculation results are shown in Table 3. Shown below.

[0072] [Table 3]

[0073] As shown in Table 3, 35DCzPPy is in the ground state (S0 state) and PCCH is in the ground state. In the case of the S0 state or radical cation state, the energy difference between the initial and final states is Since the stabilization energy is larger than 1 eV, the hydrogen atoms from the NH group of PCCH On the other hand, the dissociation reaction of PCCH is difficult to occur. When PPy is in the radical anion state, the stabilization energy is the energy difference between the initial and final states. Since the energy is less than 1 eV, the reaction occurs when the hydrogen atoms from the NH group of PCCH dissociate. In particular, when PCCH is in an excited state (T1 state), the stabilization energy is Since the S1 state is higher than the T1 state, the reaction is likely to occur. Since the PCCH has a low excitation energy, it can be said that the reaction is likely to occur even when the PCCH is in the S1 state. do.

[0074] Next, when PCCH exists alone, the hydrogen atom derived from the NH group of PCCH dissociates. The results are shown in Table 4.

[0075] [Table 4]

[0076] As shown in Table 4, when PCCH exists alone, the NH group of PCCH The final state is the state where the hydrogen atoms dissociate to infinity, and the interaction between each initial state and the final state of PCCH is The energy difference was calculated as the stabilization energy. In this case, the initial state of PCCH is the T1 state. Except for the case where The energy is greater than 1 eV. Therefore, the initial state is not an excited state (S0 state, radical In the anion and radical cation states, the hydrogen atoms derived from the NH group of PCCH are dissolved. In addition, if the initial state is the T1 state, the stabilization energy Although the stabilization energy is less than 1 eV, the stabilization energy is higher than that of 35DCzPPy. This suggests that the reaction of dissociating hydrogen atoms is unlikely to occur because of the large size of the molecule.

[0077] In other words, the reaction in which the hydrogen atom derived from the NH group of PCCH dissociates is This reaction is particularly likely to occur when PCCH coexists.

[0078] <Calculations for compounds that can react with PCCH> Next, by coexisting with PCCH in the light-emitting layer, the water in the NH group of the PCCH Calculations were performed to investigate the molecular structures of organic compounds in which reactions involving the dissociation of elementary atoms can occur. The structures and abbreviations of the compounds used in the calculations are listed below.

[0079] [ka]

[0080] The calculation method is the same as that for the reaction mechanism between PCCH and 35DCzPPy. The 1-state PCCH and the ground state (S0 state) 2,4,6-tris[3-(9H-carba (mCzP3Pm) and hydrogen atoms in The reaction path and energy diagram obtained from the analysis of the transfer reaction are shown in Fig. 3(A). PCCH and the ground state (S0 state) of 4,6-bis[3-(9H-carbazole-9- Hydrogen atom transfer reaction in 4,6mCzP2Pm and 4,6mCzP2Pm The reaction pathway and energy diagram obtained from the reaction analysis are shown in Fig. 3(B), and the T1 state of PC CH and the ground state (S0 state) of 2,6-bis[3-(9H-carbazol-9-yl) Phenyl]pyrazine (abbreviation: 2,6mCzP2Pr) and the solution of hydrogen atom transfer reaction in The reaction pathway and energy diagram obtained by the analysis are shown in Fig. 4(A), and the T1 state of PCCH and , 2,4-bis[3-(9H-carbazol-9-yl)phenyl] in the ground state (S0 state) Hydrogen atom transfer reaction between α-1,3,5-triamidine (abbreviation: mCzP2Tzn) and The reaction pathway and energy diagram obtained from the reaction analysis are shown in Figure 4(B).

[0081] In Figure 3(A), PCCH in the T1 state and mCzP3Pm in the ground state (S0 state) are The energy of the infinitely dissociated state was used as the reference. The activation energy of the reaction is very small, at 0.01 eV, and it can occur easily at room temperature. Furthermore, in the final state after the hydrogen atom transfer, PCC and mCzP3Pm-H are in a radical state. The energy of the final state is lower than the energy of the initial state, and the reaction is exothermic. From this, it can be seen that PCC When H and mCzP3Pm are in a molecular configuration that allows them to form hydrogen bonds, the migration of the hydrogen atom Dynamic reactions may occur.

[0082] In addition, the PCCH in the T1 state and the ground state (S0 state) 4,6mCzP2Pm, 2,6 In mCzP2Pr and mCzP2Tzn, the hydrogen atom based on the NH group of PCCH There is no activation energy barrier for the electron transfer reaction, and PCCH and these organic compounds When the molecules are arranged in a way that allows them to form hydrogen bonds, a hydrogen atom transfer reaction occurs quickly. Therefore, in Figures 3(B), 4(A) and 4(B), the PCCH in the T1 state and and the ground state (S0 state) of 4,6mCzP2Pm, 2,6mCzP2Pr, and mCzP The energy of the state where 2Tzn is not interacting was used as the reference. In the final state, PCC, 4,6mCzP2Pm-H, 2,6mCzP2Pr-H, and mC zP2Tzn-H is in a radical state, and the energy of the final state is the energy of the initial state. This reaction is exothermic, and the temperature is lower than that of the light-emitting element. In the light-emitting layer in the excited state, PCCH, 4,6mCzP2Pm, and 2,6mCz When P2Pr and mCzP2Tzn are in a molecular configuration that forms hydrogen bonds, Hydrogen atom transfer reactions can occur rapidly.

[0083] Next, when it coexists with PCCH, the hydrogen atoms derived from the NH group of PCCH dissociate. Calculations were carried out to investigate the molecular structure of organic compounds that are more likely to undergo reactions. The structures and abbreviations of the organic compounds used are shown below. The structures and abbreviations of other compounds are as shown above. Please take this into consideration.

[0084] [ka]

[0085] [ka]

[0086] The calculations were performed on PCCH (molecule 1) in the T1 state and various organic compounds ( Starting with molecule 2), the hydrogen atoms from the NH group of PCCH are dissociated into PCC, and the hydrogen atoms from the NH group are dissociated into PCC. The final state is the state in which the elementary atom is bonded to the organic compound (molecule 2) at infinity and becomes stable. The energy difference was calculated as the stabilization energy. The calculation results are shown in Tables 5 and 6. 6 has the LUMO (Lowest Unoccupied Molecular The results of calculations of the lowest unoccupied orbital (also called the lowest unoccupied orbital) levels are also shown.

[0087] [Table 5]

[0088] [Table 6]

[0089] As shown in Table 5, 4,4',4' is an organic compound that does not have a nitrogen-containing six-membered heteroaromatic skeleton. '-Tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA) and 1, In the presence of 3-bis(N-carbazolyl)benzene (abbreviation: mCP), P The stabilization energy for dissociation of the hydrogen atom in the NH group of CCH is greater than 1 eV. , it can be seen that the reaction is unlikely to occur.

[0090] On the other hand, as shown in Table 6, 1,3,5 organic compounds with nitrogen-containing six-membered heteroaromatic skeletons -Tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 35DCz PPy, 5,5'-bis[3-(9H-carbazol-9-yl)phenyl]-3,3' -bipyridine (abbreviation: 5,5'mCzP2BPy(3)), 4,4'-bis[3-(9H -carbazol-9-yl)phenyl]-2,2'-bipyridine (abbreviation: 4,4'mCz In the case where P2BPy), 4,6mCzP2Pm, and mCzP3Pm coexist, The stabilization energy for dissociation of the hydrogen atom in the NH group of PCCH is less than 0 eV and exothermic. Since it is a reaction, it is clear that the reaction is likely to occur.

[0091] Next, the LUMO level (calculated value) of the organic compound having the nitrogen-containing six-membered heteroaromatic skeleton, Stabilization energy for dissociation of hydrogen atoms from the NH group of PCCH (initial and final states) The correlation between the energy difference between the

[0092] As shown in Figure 5, the lower the LUMO level of the organic compound (molecule 2), the greater the The stabilization energy when the hydrogen atom derived from the NH group dissociates becomes smaller, and the hydrogen atom becomes P This resulted in it being more easily dissociated from CCH.

[0093] As mentioned above, when PCCH is present, the hydrogen atom of the NH group is likely to dissociate. The organic compound is not limited to 35DCzPPy, but may be any organic compound having a nitrogen-containing six-membered heteroaromatic skeleton. Anything is fine.

[0094] In addition, the dissociation energy of the hydrogen atom dissociating from the NH group is different from that of the molecular structure other than the NH group. Therefore, as mentioned above, the hydrogen atom derived from the NH group dissociates. The organic compounds that are prone to undergo such reactions are not limited to PCCH. As shown in the above, the compound has a nitrogen-containing five-membered heterocyclic skeleton having an NH group, or a secondary amine skeleton or a primary amine skeleton. This reaction also occurs in organic compounds having the formula:

[0095] A compound having a nitrogen-containing five-membered heterocyclic skeleton having an NH group, a secondary amine skeleton, or a primary amine skeleton. Examples of organic compounds that can be used include those with a pyrrole skeleton, an imidazole skeleton, or a triazole skeleton having an NH group. Organic compounds having an azole skeleton, a tetrazole skeleton, or an aromatic amine skeleton having an NH group Examples of the pyrrole skeleton having an NH group include an indole skeleton and and carbazole skeletons. In addition, secondary amine skeletons and primary amine skeletons having an NH group are also included. Examples of the arylamine skeleton include a diarylamine skeleton and a monoarylamine skeleton. can be.

[0096] Therefore, the light-emitting layer of the light-emitting device contains an organic compound having a nitrogen-containing six-membered heteroaromatic skeleton. In this case, a nitrogen-containing five-membered heterocyclic skeleton having an NH group such as PCCH, a secondary amine skeleton, or The content of the organic compound having a primary amine skeleton is preferably low.

[0097] Specifically, when the organic compound 131_1 has a nitrogen-containing six-membered heteroaromatic skeleton, it emits light. In the layer 130, a nitrogen-containing five-membered heterocyclic skeleton having an NH group, a secondary amine skeleton, or a primary The content of the organic compound containing an amine skeleton is preferably in a weight ratio relative to the organic compound 131_1. It is preferable that the NH group is 0.03 or less, and more preferably 0.003 or less. Organic compounds containing a nitrogen-containing five-membered heterocyclic skeleton, a secondary amine skeleton, or a primary amine skeleton and an organic compound 131_1 having a nitrogen-containing six-membered heteroaromatic skeleton, Nitrogen-containing five-membered heterocyclic skeleton, secondary amine skeleton, or primary amine skeleton in which the atom has an unpaired electron The content of the organic compound containing the hydroxyl group is preferably 0.5 wt.% to the organic compound 131. 0.03 or less, more preferably 0.003 or less, and has a nitrogen-containing six-membered heteroaromatic skeleton. The content of organic compounds in which an additional hydrogen atom is bonded to organic compound 131_1 is The weight ratio of 31_1 is preferably 0.03 or less, more preferably 0.003 or less. be.

[0098] In addition to the calculation based on weight ratio, after separating impurities using a column, etc., The abundance ratio can also be estimated from the ratio of the peaks appearing on the long side.

[0099] In addition, organic compound 131_1 has a nitrogen-containing six-membered heteroaromatic skeleton, and organic compound 131 When _2 has at least one of a nitrogen-containing five-membered heterocyclic skeleton or a tertiary amine skeleton, luminescence In the layer 130, a nitrogen-containing five-membered heterocyclic skeleton having an NH group, a secondary amine skeleton, or a primary The content of the organic compound containing an amine skeleton is preferably in a weight ratio to the organic compound 131_2. It is preferable that the NH group is 0.01 or less, and more preferably 0.001 or less. Organic compounds containing a nitrogen-containing five-membered heterocyclic skeleton, a secondary amine skeleton, or a primary amine skeleton and an organic compound 131_1 having a nitrogen-containing six-membered heteroaromatic skeleton, Nitrogen-containing five-membered heterocyclic skeleton, secondary amine skeleton, or primary amine skeleton in which the atom has an unpaired electron The content of the organic compound containing the hydroxyl group is preferably 0.5 wt.% to the organic compound 131_2. 01 or less, more preferably 0.001 or less, and has a nitrogen-containing six-membered heteroaromatic skeleton The content of organic compounds in which an additional hydrogen atom is bonded to organic compound 131_1 is The weight ratio of 31_2 is preferably 0.01 or less, more preferably 0.001 or less. be.

[0100] <Material> Next, components of a light-emitting element according to one embodiment of the present invention will be described in detail below.

[0101] <Light-emitting layer> In the light-emitting layer 130, the host material 131 is present in the largest amount by weight, and the guest material 132 is dispersed in the host material 131. When the guest material 132 is a fluorescent compound, the light-emitting layer S1 standard of host material 131 (organic compound 131_1 and organic compound 131_2) of 130 The S1 level is preferably higher than the S1 level of the guest material (guest material 132) of the light-emitting layer 130. In addition, when the guest material 132 is a phosphorescent compound, the host material 131 of the light-emitting layer 130 The T1 level of the organic compound 131_1 and the organic compound 131_2 is It is preferable that the T1 level is higher than the T1 level of the host material (guest material 132).

[0102] The organic compound 131_1 is preferably a compound having a nitrogen-containing six-membered heteroaromatic skeleton. Specifically, a pyridine skeleton, a diazine skeleton (pyrazine skeleton, pyrimidine skeleton, and and pyridazine skeleton), and compounds having a triazine skeleton. Examples of compounds having a nitrogen-containing heteroaromatic skeleton include pyridine derivatives, bipyridines, and the like. Lysine derivatives, pyrimidine derivatives, triazine derivatives, quinoxaline derivatives, dibenzoxazole derivatives Examples of compounds include benzoxaline derivatives, phenanthroline derivatives, and purine derivatives. In addition, as the organic compound 131_1, a material having a higher electron transporting property than a hole transporting property (electron transporting property Materials) can be used, 1 x 10 -6 cm 2 Materials with electron mobility of ≥ 1000 V It is preferable that there is.

[0103] Specifically, for example, bathophenanthroline (abbreviated as BPhen), bathocuproine Heterocyclic compounds with a pyridine skeleton, such as BCP, and 2-[3-(dibenzothiazolinone) [4-(4-(4-phenyl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTP DBq-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]quinoxazone Sarin (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carba [f,h]quinoxaline (abbreviation: 2CzPDBq -III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h ]quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-(dibenzothiophene 6mDBTPD Bq-II), 2-[3-(3,9'-bi-9H-carbazol-9-yl)phenyl] Dibenzo[f,h]quinoxaline (abbreviation: 2mCzCzPDBq), 4,6-bis[3- (Phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mD BTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl ] Heterocyclic compounds with a diazine skeleton such as pyrimidine (abbreviation: 4,6mCzP2Pm) and 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-3-yl] 4,6-diphenyl-1,3,5-triazine (abbreviation: Heterocyclic compounds with triazine skeletons such as PCCzPTzn) and 3,5-bis[3- (9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1 ,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), etc. Among the heterocyclic compounds described above, heterocyclic compounds having a pyridine skeleton such as However, the triazine skeleton, diazine (pyrimidine, pyrazine, pyridazine) skeleton, or pyridine Heterocyclic compounds having a lysine skeleton are preferred because they are stable and highly reliable. Heterocyclic compounds with a ring structure have high electron transport properties and contribute to reducing the driving voltage. (2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene -2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), ri[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridinyl) Polymer compounds such as PF-BPy (PF-BPy) can also be used. The substances mentioned here are mainly 1×10 -6 cm 2 / Vs or higher electron mobility It should be noted that any substance other than those mentioned above can be used as long as it has a higher electron transporting property than hole transporting property. It's okay.

[0104] The organic compound 131_2 has a nitrogen-containing five-membered heterocyclic skeleton or a tertiary amine skeleton. Specifically, compounds having a pyrrole skeleton or an aromatic amine skeleton are preferred. Examples include indole derivatives, carbazole derivatives, and triarylamine derivatives. Examples of the nitrogen-containing five-membered heterocyclic skeleton include an imidazole skeleton, a triazole skeleton, and the like. Examples of the organic compound 131_2 include a tetrazole skeleton and a benzole skeleton. , a material with higher hole transporting ability than electron transporting ability (hole transporting material) can be used, and -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The conductive material may be a polymer compound.

[0105] As the material having high hole transporting properties, specifically, aromatic amine compounds such as N, N'-Di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DT DPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenyla N,N'-bis[4-[bis(3-methylphenyl) {N,N'-diphenyl-(1,1'-biphenyl)-4,4' -diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylamino) [phenyl]-N-phenylamino]benzene (abbreviation: DPA3B), etc. .

[0106] Specific examples of carbazole derivatives include 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 [N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation :PCzTPN2), 3-[N-(9-phenylcarbazol-3-yl)-N-phenyl 3,6-bis[N- (9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazol PCzPCA2, 3-[N-(1-naphthyl)-N-(9-phenylcarbazone] [carbazol-3-yl]amino]-9-phenylcarbazole (abbreviation: PCzPCN1) The following can be mentioned:

[0107] Other carbazole derivatives include 4,4'-di(N-carbazolyl)biphene. Nyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzoyl Zene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthryl)phenyl]- 9H-Carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl] nyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.

[0108] Also, N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl] ]-9H-carbazol-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-anthryl)phenyl] Phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), N,9-diphenyl -N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H- Carbazol-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-anthryl)phenyl]-9 H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl) N-(9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g, p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1) can be used. can.

[0109] In addition, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenyl ether) 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 Polymer compounds such as [(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used. can.

[0110] Furthermore, examples of materials with high hole transport properties include 4,4'-bis[N-(1-naphthyl)-2-methyl-2-propanol]. N,N'-(phenyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD) Bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4, 4'-diamine (abbreviation: TPD), 4,4',4''-tris(carbazol-9-yl) ) triphenylamine (abbreviation: TCTA), 4,4',4''-tris[N-(1-naphthyl) 4,4-Triphenylamine (abbreviation: 1'-TNATA) ',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)triphenyl 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}phenylamino N-(9,9-dimethyl-2-diphenylamino-9H- Fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl) N-phenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl) Triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9- Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1B) P), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl) Triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''- (9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBN BB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)a amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazol-3-yl) -N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N', N''-triphenyl-N,N',N''-tris(9-phenylcarbazole-3-yl) N-(4-biphenyl)benzene-1,3,5-triamine (abbreviation: PCA3B) -N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-chlor PCBiF, N-(1,1'-biphenyl-4-yl) -N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-di Methyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 9,9-dimethyl-N -phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] Fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl -9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluorene-2-a PCBASF, 2-[N-(9-phenylcarbazol-3-yl)-N -phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7-bi Spiro-9,9'-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro Bifluorene (abbreviation: DPA2SF), N-[4-(9H-carbazol-9-yl)fluorene] N,N'-phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), Bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-di Aromatic amine compounds such as methylfluorene-2,7-diamine (abbreviation: YGA2F) Also, 3-[4-(1-naphthyl)-phenyl]-9-phenyl can be used. -9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthryl)-phenyl 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 Nylcarbazole (abbreviation: CzTP), 3,6-di(9H-carbazol-9-yl)- 9-phenyl-9H-carbazole (abbreviation: PhCzGI), 2,8-di(9H-carbazole) amine compounds such as benzothiazolinone (Cz2DBT), Among the compounds mentioned above, compounds having a pyrrole skeleton, an aromatic Compounds having an aromatic amine skeleton are preferred because they are stable and highly reliable. The compound having the formula (I) has high hole transporting properties and contributes to reducing the driving voltage.

[0111] The organic compound 131_2 may have an imidazole skeleton, a triazole skeleton, or a tetraazole skeleton. Compounds having a nitrogen-containing five-membered heterocyclic skeleton such as a trazole skeleton can be used. Examples of suitable phenylalanines include 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl)- phenyl)-1,2,4-triazole (abbreviation: TAZ), 9-[4-(4,5-diphenyl 4H-1,2,4-triazol-3-yl)phenyl]-9H-carbazole ( Abbreviation: CzTAZ1), 2,2',2''-(1,3,5-benzenetriyl)tris( 1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzo Thiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II) etc. can be used.

[0112] Contains a nitrogen-containing five-membered heterocyclic skeleton having an NH group, a secondary amine skeleton, or a primary amine skeleton Specifically, the organic compound may be, for example, an organic compound having an NH group and That is, compounds having a part of the skeleton of the above pyrrole skeleton can be mentioned. , imidazole skeleton, triazole skeleton, tetrazole skeleton, triarylamine skeleton, etc. From compounds that can be used as organic compound 131_2 having a nitrogen-containing five-membered heterocycle A small number of aryl or alkyl groups bonded to the nitrogen of the skeleton or tertiary amine skeleton Examples of compounds include those having a structure in which at least one is substituted with hydrogen.

[0113] In the light-emitting layer 130, the guest material 132 is not particularly limited, but may be a fluorescent material. The compounds include anthracene derivatives, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, stilbene derivatives, acridone derivatives, Marine derivatives, phenoxazine derivatives, phenothiazine derivatives, etc. are preferred, and examples thereof include the following: The following materials can be used:

[0114] Specifically, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2 ,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl -9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2 BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoro (9-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-diazo amine (abbreviation: 1,6tBu-FLPAPrn), N,N'-diphenyl-N,N'-bis [4-(9-phenyl-9H-fluoren-9-yl)phenyl]-3,8-dicyclohexyl Xylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'-biphenyl bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbe 4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl) -4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA) , 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthracene) N,9-diphenyl-N-[4- (10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation Name: PCAPA), Perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl- 9H-carbazol-3-yl)triphenylamine (abbreviation: 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)phenyl] phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9 ,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1 ,4-Phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N '',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10 ,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl -2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2 PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthracene] aryl]-N,9-diphenyl-9H-carbazol-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'-biphenyl) (9H-carbazol-9-yl)phenyl)-N-[4-(9H-carbazol-9-yl)phenyl]-N- Phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenyl Dianthracen-9-amine (abbreviation: DPhAPhA), Coumarin 6, Coumarin 545T , N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 2,8-di-te rt-Butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyl Tetrathracene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl) 2-(2-(2-phenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), [4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl 2-(2-methyl-6-[(2,3-dimethyl- ... ,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl ]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N ',N'-Tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methyl phenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl 2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl )ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI) , 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3, 6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl] -4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2, 6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-yl 2-(2,6-bis[2-(8- Methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H -benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}p Dopanedinitrile (abbreviation: BisDCJTM), 5,10,15,20-tetraphenyl Bisbenzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene , etc.

[0115] The guest material 132 (phosphorescent compound) is iridium, rhodium, or platinum-based Organometallic complexes or metal complexes are mentioned, among which organic iridium complexes, e.g., iridium The orthometalated ammonium complex is preferred. The orthometalated ligand is 4H-triazolium. 1H-triazole ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidine ligands Examples of the metal complexes include quinazine, pyrazine, and isoquinoline ligands. Examples of the platinum complex include a platinum complex having a porphyrin ligand.

[0116] Examples of substances having a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo {3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir(mpp tz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-trimethyl- Triazolato)iridium(III) (abbreviation: Ir(Mptz)3), tris[4-(3- Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]i Iridium(III) (abbreviation: Ir(iPrptz-3b)3), tris[3-(5-biphenyl] (phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]irid Ir(III) (abbreviated as Ir(iPr5btz)3), a 4H-triazole skeleton and organometallic iridium complexes with 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-Triazolate)iridium(III) (abbreviation: Ir(Prtz1-Me) 3) and fac-triazole-based organometallic iridium complexes. S[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]isopropyl Iridium(III) (abbreviation: Ir(iPrpmi)3), tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(I II) Imidazole skeleton-containing compounds such as Ir(dmpimpt-Me) Organic metal iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinato- N,C 2’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FI r6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Ili Dium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis (Trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) pico Ir(CF3ppy)2(pic) (fluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate (abbreviation: FIr(acac)) Among the above, 4H-triazole is an organometallic iridium complex. a nitrogen-containing five-membered heterocyclic skeleton such as a 1H-triazole skeleton and an imidazole skeleton; The organometallic iridium complexes have high triplet excitation energy and are highly reliable and highly efficient. It is particularly preferred because it is also excellent in

[0117] Furthermore, examples of substances having a green or yellow emission peak include tris(4-methylphenyl) Ir(mppm)3, Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm)3), (acetylacetonato)bis(6-methyl-4-phenylpyridine) Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetylacetonate ruacetonato)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-dimethyl 2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl- κC}iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), ( acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Organometallic iridium compounds with pyrimidine skeletons, such as Ir(dppm)2(acac) complexes and (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetyl arylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridide Pyrazine skeletons such as Ir(III) (abbreviation: Ir(mppr-iPr)2(acac)) Organometallic iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato-N ,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(ac ac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)), tris(benzo[h]quinolinato)iridium Ir(III) (abbreviation: Ir(bzq)3), tris(2-phenylquinolinato-N,C 2 ’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinolinato- N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(pq)2(ac Organometallic iridium complexes with pyridine skeletons such as bis(2,4-difluoromethyl) Phenyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetylacetoner Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenyl) (phenyl)pyridinato-N,C 2’}Iridium(III) acetylacetonate( Abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazol- -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(a In addition to organometallic iridium complexes such as tris(acetylacetonato)(monophenyl) Anthroline) terbium(III) (abbreviation: Tb(acac)3(Phen)) Among the above, organometallic iridium complexes having a pyrimidine skeleton are Dium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0118] Furthermore, examples of substances having 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 (5mdppm)2(dpm)), bis[4,6-di(naphthalen-1-yl)pyrimidinyl] Nato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(d1npm)2( Organometallic iridium complexes with pyrimidine skeletons, such as (acetylacetonyl acetone) Iridium(III) (abbreviation: I r(tppr)2(acac)), bis(2,3,5-triphenylpyrazinate)(dipyr Valoylmethanato)iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]i Ir(Fdpq)2(acac) and other pyrazine-based compounds Organometallic iridium complexes and tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinolinato) -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq)2( In addition to organometallic iridium complexes with pyridine skeletons such as acac), 2,3,7, 8,12,13,17,18-Octaethyl-21H,23H-porphyrin platinum(II) ) (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3-propanediol). Eu(DB)(propanedionato)(monophenanthroline)europium(III) M)3(Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetate [Tonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA)3( Among the above, rare earth metal complexes such as pyrimidine skeletons are Organometallic iridium complexes having the above structure are particularly preferred because they are remarkably excellent in reliability and luminous efficiency. In addition, organometallic iridium complexes with a pyrazine skeleton can emit red light with good chromaticity. can be done.

[0119] The light-emitting material contained in the light-emitting layer 130 is a material capable of converting triplet excitation energy into light. The material capable of converting triplet excitation energy into luminescence is preferably a phosphorescent material. In addition to the thermally activated delayed fluorescence compounds, Therefore, phosphorescence The term "thermally activated delayed fluorescent compound" may be read as "thermally activated delayed fluorescent material." A thermally activated delayed fluorescent material is a material that has a triplet excitation energy level and a singlet excitation energy level. The difference between the triplet and singlet excited states is small, and reverse intersystem crossing allows the energy to be transferred from the triplet excited state to the singlet excited state. Therefore, the triplet excited state can be converted into a small amount of thermal energy. Therefore, upconversion (reverse intersystem crossing) from the singlet excited state is possible. Furthermore, thermally activated delayed fluorescence can be efficiently obtained. The conditions for this are the energies of the triplet and singlet excited energy levels. The difference is preferably greater than 0 eV and not greater than 0.2 eV, more preferably greater than 0 eV and not greater than 0 The most notable features are that the energy density is less than 0.1 eV.

[0120] When the thermally activated delayed fluorescent material is composed of one kind of material, for example, the following material is used: It is possible.

[0121] First, fullerene and its derivatives, acridine derivatives such as proflavine, and eosin are listed. In addition, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S n), platinum (Pt), indium (In), or palladium (Pd) Examples of the metal-containing porphyrin include protoporphyrin. Porphyrin-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)), etioporphyrin-tin fluoride complex (SnF2(E tio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. It can be obtained.

[0122] In addition, as a thermally activated delayed fluorescent material composed of one kind of material, π-electron-rich heteroaromatic Heterocyclic compounds having an aromatic ring and a π-electron-deficient heteroaromatic ring can also be used. is 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3- a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol {4,6-diphenyl-1,3,5-triazine (PC CzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4, 6-Diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5- Phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl 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 -9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc. The heterocyclic compounds have a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, Among them, a skeleton having a π-electron-deficient heteroaromatic ring is preferred. Among them, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) or triazine skeleton The azine skeleton is preferred because it is stable and reliable. Among the skeletons that have such structures, acridine skeleton, phenoxazine skeleton, thiophene skeleton, and furan skeleton are Since the pyrrole skeleton and the pyrrole skeleton are stable and reliable, any of the skeletons can be used. It is preferable that the pyrrole skeleton has one or more of the following. skeleton, a carbazole skeleton, and 3-(9-phenyl-9H-carbazol-3-yl)- A 9H-carbazole skeleton is particularly preferred. The substance in which the π-electron-rich heteroaromatic ring is directly bonded to the π-electron-deficient heteroaromatic ring exhibits the donor property of the π-electron-rich heteroaromatic ring. The acceptor properties of the heteroaromatic rings are both strong, and the energy levels of the singlet excited state and triplet excited state are This is particularly preferable because the difference between the energy level of the excited state and the energy level of the excited state is small.

[0123] In addition, in the light-emitting layer 130, materials other than the host material 131 and the guest material 132 are It may have.

[0124] The material that can be used for the light-emitting layer 130 is not particularly limited, but examples thereof include anthracene, Helical derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g, p] chrysene derivatives and other condensed polycyclic aromatic compounds, specifically 9,10-diphenyl Phenylanthracene (abbreviation: DPAnth), 6,12-dimethoxy-5,11-diphenyl Nilcrysene, 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'-Bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl) Diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)di Phenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation Among these and other known substances, the above-mentioned Singlet excited energy level or triplet excited energy level higher than the excited energy level of the guest material 132 One or more substances having an excitation energy level may be selected and used.

[0125] In addition, for example, a compound having a heteroaromatic skeleton such as an oxadiazole derivative may be used as the light-emitting layer 1. 30. Specifically, for example, 2-(4-biphenylyl)-5-(4 -tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD) and 1 ,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole- 2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-o 4,9H-(2-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 4'-Bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) and the like heterocyclic compounds.

[0126] In addition, metal complexes having heterocycles (e.g., zinc and aluminum-based metal complexes) emit light. For example, quinoline ligands, benzoquinoline ligands, oxalyl ligands, Examples of such metal complexes include those having a thiazole ligand or a thiazole ligand. For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(8-quinolinolato)aluminum(III) Bis(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2 ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum ( III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq) and metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as: In addition, bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnP BO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnB Metal complexes with oxazole or thiazole ligands such as TZ are also used. It is possible.

[0127] The light-emitting layer 130 may be composed of two or more layers. When the light-emitting layer 130 is formed by laminating the first light-emitting layer and the second light-emitting layer in this order from the hole transport layer side, a substance having hole transport properties is used as a host material for the first light-emitting layer, and a substance having hole transport properties is used as a host material for the second light-emitting layer In addition, a structure in which a substance having an electron transporting property is used as the first light-emitting layer and the second light-emitting layer is also available. The light-emitting materials in the optical layer and the optical layer may be the same or different materials, and they may emit light of the same color. Even if the material has a function of emitting light, it may have a function of emitting light of different colors. The two light-emitting layers may contain light-emitting materials that emit light of different colors. By using each of these layers, multiple light emissions can be obtained simultaneously. It is preferable to select a light-emitting material for each light-emitting layer so that the resulting light emitted will be white.

[0128] The light-emitting layer 130 can be formed by a deposition method (including a vacuum deposition method), an ink-jet method, a coating method, a grating method, or the like. It can be formed by a method such as rabbet printing. In addition to the above-mentioned materials, quantum dots and the like can also be used. Even if the inorganic compound or polymer compound (oligomer, dendrimer, polymer, etc.) good.

[0129] <Hole injection layer> The hole injection layer 111 is formed by injecting 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, and is used in materials such as transition metal oxides and fluorine. It is formed by phthalocyanine derivatives or aromatic amines. Examples include molybdenum oxide, vanadium oxide, ruthenium oxide, and tungsten oxide. , manganese oxide, etc. Phthalocyanine derivatives include phthalocyanine, Examples of aromatic amines include benzidine derivatives and phenyl Diamine derivatives, etc. Polymer compounds such as polythiophene and polyaniline Materials such as self-doped polythiophenes, poly(ethylenediamines), can also be used. Typical examples include poly(oxythiophene) / poly(styrenesulfonic acid).

[0130] The hole injection layer 111 is made of a compound material including a hole transporting material and a material that exhibits electron accepting properties. Alternatively, a layer containing a material exhibiting electron accepting properties and a layer containing a material exhibiting electron accepting properties may be used. A stack of layers containing hole transport materials may also be used. It is possible to exchange charges in the presence of a magnetic field. Materials that exhibit electron-accepting properties include quinodimethane. Organic acceptors such as benzophenone derivatives, chloranil derivatives, and hexaazatriphenylene derivatives Specifically, 7,7,8,8-tetracyano-2,3,5,6- Tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7, 10,11-Hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation These compounds have electron-withdrawing groups (halogen groups or cyano groups), such as hydroxybenzoates (HAT-CN). In addition, transition metal oxides, for example, oxides of metals from Groups 4 to 8, can be used. In general, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, These include tungsten oxide, manganese oxide, and rhenium oxide. Among these, it is preferred because it is stable, has low hygroscopicity, and is easy to handle.

[0131] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. x10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The aromatic amines and carboxylic acids listed as examples of hole transport materials that can be used in the light-emitting layer 130 are Also usable are benzol derivatives, aromatic hydrocarbons, stilbene derivatives, etc. The hole transporting material may be a polymer compound.

[0132] Other examples of hole transport 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 2-tert-butylanthracene (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]anthracene 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7- Tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl 9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,1 0'-Diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl) 10,10'-bis[(2,3,4,5,6-pentafluorophenyl)-9,9'-bianthryl, (phenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, etc. In addition, pentacene, coronene, etc. can also be used. -6 cm 2 / Vs or more, and an aromatic hydrocarbon having 14 to 42 carbon atoms. It is more preferable to use

[0133] The aromatic hydrocarbon may have a vinyl skeleton. Examples of aromatic hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl. (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] anthracene (abbreviation: DPVPA), etc.

[0134] Also, 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]fluoren phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(benzyl) (benzophenone-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II ), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)fluorene phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl [(9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation :DBTFLP-IV), 4-[3-(triphenylen-2-yl)phenyl]dibenzo Thiophene compounds such as thiophene (abbreviation: mDBTPTp-II), furan compounds, Examples of compounds that can be used include olefin compounds, triphenylene compounds, and phenanthrene compounds. Among the compounds mentioned above, those with pyrrole skeleton, furan skeleton, thiophene skeleton, and aromatic amine skeleton are Compounds having such a skeleton are preferred because they are stable and reliable. The material has a high hole transporting property and also contributes to reducing the driving voltage.

[0135] <Hole transport layer> The hole transport layer 112 is a layer containing a hole transport material. The hole transporting layer 112 can be formed by the hole injection layer 111. The HOM of the hole injection layer 111 has a function of transporting the injected holes to the light-emitting layer 130. O(Highest Occupied Molecular Orbital) It is preferable that the HOMO level is the same as or close to the HOMO level (also called occupied orbital level).

[0136] Also, 1×10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. However, other substances may be used as long as they have a higher hole transporting property than electron transporting property. The layer containing a substance with a high hole transporting property may be a single layer or a double layer of the above substance. More than one layer may be stacked.

[0137] ≪Electron transport layer≫ The electron transport layer 118 is connected to the other of the pair of electrodes (electrode 101 or electrode 102) via the electron injection layer 119. The electron transport material has the function of transporting electrons injected from the electrode 102 to the light-emitting layer 130. As the material, a material with higher electron transportability than holes can be used, and the -6 cm 2 It is preferable that the material has an electron mobility of 1 / Vs or more. As materials (materials with electron transport properties), π-electron deficient materials such as nitrogen-containing heteroaromatic compounds are Heteroaromatics and metal complexes can be used. The pyridine derivatives, bipyridine derivatives, and pyrimidine derivatives listed as electron transport materials that can Derivatives, triazine derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenazine Intramolecular derivatives, triazole derivatives, benzimidazole derivatives, oxadiazole Derivatives and the like are also listed. -6 cm 2 / Vs or higher electron mobility In addition, any other material may be used as long as it has a higher electron transporting property than a hole transporting property. The electron transport layer 118 may be formed of not only a single layer but also a In addition, two or more layers made of the above materials may be laminated.

[0138] Further, metal complexes having heterocycles are also exemplified, for example, quinoline ligands, benzoquinoline Metal complexes with oxazole, thiazole, or thiazole ligands are also suitable. 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-quinolinolato)(4-phenylphenolato)a Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as Znq, In addition, bis[2-(2-benzoxazolyl)phenolato]zinc(II)( Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) ( Metal complexes with oxazole or thiazole ligands, such as ZnBTZ Also, the following can be used.

[0139] In addition, a layer for controlling the movement of electron carriers is provided between the electron transport layer 118 and the light emitting layer 130. This is a method of adding a material with high electron transporting properties to a material with high electron trapping properties. A layer containing a small amount of This structure prevents electrons from penetrating the light-emitting layer. This is highly effective in suppressing problems that arise from the above (for example, a reduction in the device life).

[0140] ≪Electron injection layer≫ The electron injection layer 119 promotes electron injection by reducing the electron injection barrier from the electrode 102. For example, Group 1 metals, Group 2 metals, or their oxides and halides In addition, the electron transport material and the corresponding electron transport material can be used. A composite material of a material exhibiting electron donating properties can also be used. Examples include Group 1 metals, Group 2 metals, and oxides thereof. are lithium fluoride (LiF), sodium fluoride (NaF), and cesium fluoride (CsF ), calcium fluoride (CaF2), lithium oxide (LiO x ) and other alkaline gold Metals, alkaline earth metals, or compounds thereof can be used. A rare earth metal compound such as erbium (ErF3) can be used. An electride may be used for 119. The electride may be, for example, calcium. Examples include a material in which electrons are highly concentrated in a mixed oxide of aluminum and silicon. The injection layer 119 may be made of a material that can be used in the electron transport layer 118 .

[0141] The electron injection layer 119 may contain a composite material formed by mixing an organic compound and an electron donor (donor). Such composite materials may be formed by electron donors giving electrons to organic compounds. In this case, the organic compound is It is preferable that the material is excellent in transporting the generated electrons. Specifically, for example, the above-mentioned The material constituting the electron transport layer 118 (metal complex, heteroaromatic compound, etc.) can be used. The electron donor may be any substance that exhibits electron donating properties to organic compounds. For the metal, alkali metals, alkaline earth metals and rare earth metals are preferred, and lithium, sodium , cesium, magnesium, calcium, erbium, ytterbium, etc. In addition, alkali metal oxides and alkaline earth metal oxides are preferred, and lithium oxide, calcium oxide, Examples of oxides include sodium oxide and barium oxide. Lewis oxides such as magnesium oxide are also included. A base can also be used. In addition, organic compounds such as tetrathiafulvalene (TTF) can be used. You can also use objects.

[0142] 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. The light-emitting layer, the hole-injecting layer, the hole-transporting layer, the electron In addition to the materials mentioned above, inorganic compounds such as quantum dots and high molecular weight compounds can be used for the transport layer and electron injection layer. A polymer compound (oligomer, dendrimer, polymer, etc.) may also be used.

[0143] ≪Quantum dots≫ Quantum dots are semiconductor nanocrystals with sizes ranging from several nanometers to several tens of nanometers, and are 1×10 3 From pieces 1×10 6 Quantum dots are composed of about 100 atoms. Therefore, even if quantum dots are made of the same material, the emission wavelengths vary depending on the size. Therefore, by changing the size of the quantum dots used, light emission can be easily The wavelength can be changed.

[0144] In addition, quantum dots have a narrow peak width in the emission spectrum, which allows for emission of light with good color purity. Furthermore, the theoretical internal quantum efficiency of quantum dots is said to be nearly 100%. This is significantly more than 25% of organic compounds that exhibit fluorescence, and 25% of organic compounds that exhibit phosphorescence. This means that quantum dots can be used as light-emitting materials. This allows for the production of a light-emitting device with high luminous efficiency. Since the inherent stability is also excellent, a light emitting device that is preferable in terms of life can be obtained. This can be done.

[0145] The materials that make up quantum dots include elements from Group 14, Group 15, Group 16, and complexes. Compounds consisting of several Group 14 elements, and compounds consisting of elements belonging to Groups 4 to 14 and Group 16 elements Compounds, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements , compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, Compounds of group 11 elements and group 17 elements, iron oxides, titanium oxides, chalcogenide spines Examples of suitable materials include semiconductor clusters.

[0146] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, and sulfur selenide Lead, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, arsenide 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, selenium arsenic nitride, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, Bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium Aluminum, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide , aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride Sulfur dioxide, 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, molyb sulfide vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide Aluminum, silicon nitride, germanium nitride, aluminum oxide, barium titanate, selenium and zinc Compounds of lead and cadmium, compounds of indium, arsenic and phosphorus, compounds of 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, compounds of copper and indium Examples of the compounds include indium and sulfur compounds, and combinations thereof. In addition, alloy quantum dots, whose compositions are expressed in any ratio, may be used. For example, alloy quantum dots of cadmium, selenium, and sulfur can be obtained by changing the ratio of the elements. This is one of the effective methods to obtain blue light emission, because the emission wavelength can be changed by It is one.

[0147] Quantum dot structures include core type, core-shell type, and core-multishell type. Either of these can be used, but it is also possible to cover the core with another inorganic compound with a wider band gap. By forming a shell of material, defects and dangling bonds on the nanocrystal surface can be eliminated. This significantly improves the quantum efficiency of light emission, It is preferable to use core-shell or core-multishell quantum dots. Examples of materials include zinc sulfide and zinc oxide.

[0148] In addition, quantum dots have a high proportion of surface atoms, making them highly reactive and prone to aggregation. Therefore, a protective agent or a protective group is attached to the surface of the quantum dots. It is preferable that the protecting agent is attached or the protecting group is provided. It can prevent aggregation and increase solubility in solvents. It can also reduce reactivity and improve electrical conductivity. It is also possible to improve stability. Examples of protecting agents (or protecting groups) include polio Polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene Polyoxyethylene alkyl ethers such as ethylene oleyl ether, tripropyl phosphite phosphine, tributylphosphine, trihexylphosphine, trioctylphosphine, etc. Trialkylphosphines, polyoxyethylene n-octylphenyl ether, polyoxyethylene Polyoxyethylene alkylphenyl ethers such as oxyethylene n-nonylphenyl ether esters, tri(n-hexyl)amine, tri(n-octyl)amine, tri(n-decyl)amine ) Tertiary amines such as amine, tripropylphosphine oxide, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide, tridecylphosphine oxide Organic phosphorus compounds such as silylphosphine oxide, polyethylene glycol dilaurate, polyethylene glycol diesters such as polyethylene glycol distearate, Organic nitrogen compounds such as nitrogen-containing aromatic compounds such as pyridine, lutidine, collidine, and quinolines , hexylamine, octylamine, decylamine, dodecylamine, tetradecylamine aminoalkanes such as dibutylsulfone, hexadecylamine, and octadecylamine; dialkyl sulfides such as dimethyl sulfoxide and dibutyl sulfoxide; organic sulfur compounds such as alkyl sulfoxides, sulfur-containing aromatic compounds such as thiophene, palmitoyl Higher fatty acids such as acetic acid, stearic acid, and oleic acid, alcohols, sorbitan fatty acid esters esters, fatty acid modified polyesters, tertiary amine modified polyurethanes, polyethylene terephthalate Examples include amines.

[0149] As quantum dots become smaller, their band gaps become larger, so they can emit the desired wavelengths. The size of the crystal is adjusted accordingly to obtain long-range light. As a result, the emission of quantum dots shifts to the blue side, i.e., to the higher energy side. By changing the size of the filter, wavelengths in the ultraviolet, visible, and infrared regions of the spectrum can be obtained. The size (diameter) of quantum dots can be adjusted over a range of wavelengths. The range of 0.5 nm to 20 nm, preferably 1 nm to 10 nm, is usually used. The narrower the size distribution of quantum dots, the narrower the emission spectrum. The quantum dots can be formed in any shape, and can have excellent color purity. The quantum dots may be spherical, rod-shaped, disc-shaped, or have other shapes. Since the rods have the function of emitting directional light, quantum rods can be used as light-emitting materials. This makes it possible to obtain a light emitting device with better external quantum efficiency.

[0150] In most cases, organic EL devices are made by dispersing a light-emitting material in a host material. The host material is more than just a light-emitting material; it also has a high luminous efficiency. The material must have a singlet or triplet excited energy level. In particular, when a blue phosphorescent material is used as the light-emitting material, further triplet excitation is required. A host material with an energy level and excellent lifetime is required, and its development is Here, quantum dots emit light by themselves without using a host material. Even if a layer is formed, the luminous efficiency can be maintained, which is also preferable from the viewpoint of life. When the light-emitting layer is formed only with quantum dots, The polymer preferably has a core-shell structure (including a core-multishell structure).

[0151] When quantum dots are used as the light-emitting material of the light-emitting layer, the thickness of the light-emitting layer is 3 nm to 100 nm. m, preferably 10 nm to 100 nm, and the content of quantum dots in the light-emitting layer is 1 to 1 However, it is preferable to form the light-emitting layer only from quantum dots. When forming a light-emitting layer in which the quantum dots are dispersed in a host as a light-emitting material, the host material Alternatively, the host material and the quantum dots are dissolved or dispersed in a suitable liquid medium. Disperse and apply wet processes (spin coating, casting, die coating, blade coating) Coating method, roll coating method, inkjet method, printing method, spray coating method, curtain coating The phosphorescent material may be formed by a method such as the ion beam splitting method or the Langmuir-Blodgett method. For the light-emitting layer using the above, in addition to the wet process, a vacuum deposition method can also be suitably used. This can be done.

[0152] Examples of liquid media used in wet processes include methyl ethyl ketone, cyclohexane, and the like. Ketones such as xanone, fatty acid esters such as ethyl acetate, halogens such as dichlorobenzene aromatic hydrocarbons, toluene, xylene, mesitylene, cyclohexylbenzene, etc. Hydrocarbons, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, dimethylformamide Organic solvents such as dimethyl amide (DMF) and dimethyl sulfoxide (DMSO) can be used. Cut.

[0153] <Pair of electrodes> The electrode 101 and the electrode 102 function as an anode or a cathode of the light-emitting element. The electrode 101 and the electrode 102 may be made of a metal, an alloy, a conductive compound, or a mixture or laminate thereof. It can be formed using, for example.

[0154] One of the electrodes 101 and 102 is made of a conductive material that has a function of reflecting light. The conductive material is preferably aluminum (Al) or a compound containing Al. Examples of alloys containing Al include Al and L (L is titanium (Ti), neodymium (Ne), etc. (representing one or more of Nd, Ni, and La) Examples of suitable alloys include alloys containing Al and Ti, or alloys containing Al, Ni and La. Aluminum has low resistance and high light reflectivity. Since aluminum is abundant and inexpensive, the cost of manufacturing a light-emitting element using aluminum is reduced. In addition, silver (Ag) or Ag and N (N) can be used in combination with yttrium ( Y), Nd, magnesium (Mg), ytterbium (Yb), Al, Ti, gallium ( Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), Tin (Sn), iron (Fe), Ni, copper (Cu), palladium (Pd), iridium (Ir ), or an alloy containing gold (Au), etc. Examples of alloys containing silver 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, silver and ytterbium Other examples include alloys containing tungsten, chromium (Cr), molybdenum (Mo ), copper, titanium, and other transition metals can be used.

[0155] The light emitted from the light-emitting layer is emitted through one or both of the electrodes 101 and 102. Therefore, at least one of the electrodes 101 and 102 is transparent to light. It is preferable that the conductive material is formed of a conductive material having a permeability function. The transmittance of visible light is 40% or more and 100% or less, preferably 60% or more and 100% or less, or The resistivity is 1×10 -2 Examples include conductive materials with a resistance of Ω·cm or less.

[0156] The electrodes 101 and 102 have a function of transmitting light and a function of reflecting light. The conductive material may be formed of a conductive material having a visible light reflectance of 20 or less. % or more and 80% or less, preferably 40% or more and 70% or less, and the resistivity is 1×10 -2 Conductive materials with a resistance of Ω·cm or less include metals, alloys, and conductive materials. The layer can be formed by using one or more of the following compounds. Indium Tin Oxide (ITO), silicon or silicon oxide Indium tin oxide (ITSO), indium oxide-zinc oxide (Indi Indium tin oxide containing titanium, indium tin oxide, Metals such as indium oxide containing titanium oxide, tungsten oxide, and zinc oxide Oxides can be used. In addition, the thickness of the oxide is preferably within a range of 1 nm to 30 nm. A metal thin film having a thickness of 1 μm or less can be used. Examples of metals include Ag, Alloys such as Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb can be used.

[0157] In this specification and the like, a material having a function of transmitting light refers to a material having a function of transmitting visible light. Any material having the above and having electrical conductivity may be used, and examples thereof include ITO. In addition to oxide conductors, oxide semiconductors or organic conductors containing organic materials are also included. The organic conductor may be, for example, a mixture of an organic compound and an electron donor. Examples of such materials include composite materials, and composite materials made by mixing organic compounds and electron acceptors. Alternatively, inorganic carbon materials such as graphene may be used. The ratio is preferably 1×10 5 Ω·cm or less, more preferably 1×10 4 Ω cm The following is the result.

[0158] In addition, by laminating a plurality of the above materials, one or both of the electrodes 101 and 102 can be formed. may form both.

[0159] In order to improve the light extraction efficiency, the electrode is in contact with the light-transmitting electrode. A material having a higher refractive index than the electrode may be used. Any material that has the function of providing the desired electrical conductivity may be used. For example, in addition to the oxide conductors described above, oxide semiconductors and organic materials can be used. The organic material may be, for example, a light-emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, or an electron transport layer. The materials exemplified for the electron injection layer are also usable. Inorganic carbon materials and metals that are light-transmitting are also usable. A thin film can also be used, and multiple layers of several nanometers to several tens of nanometers may be stacked.

[0160] When the electrode 101 or the electrode 102 functions as a cathode, the work function is small. (3.8 eV or less) materials. For example, materials in Group 1 or 2 of the Periodic Table of Elements. Elements belonging to the group (alkali metals such as lithium, sodium, and cesium, calcium, strontium, etc.) Alkaline earth metals such as rontium, magnesium, etc.), alloys containing these elements (e.g., Rare earth metals such as Ag and Mg, Al and Li), europium (Eu), Yb, etc. An alloy containing a metal, such as an alloy containing aluminum or silver, can be used.

[0161] Furthermore, when the electrode 101 or the electrode 102 is used as an anode, a material having a large work function (4. It is preferable to use a material having a refractive index of 0 eV or more.

[0162] The electrodes 101 and 102 are made of a conductive material that reflects light and a light-transmitting material. In this case, the electrode 101 and the electrode 102 may be laminated with a conductive material having a permeability function. O2 can resonate light of a desired wavelength from each light-emitting layer and intensify the light of the desired wavelength. This is preferable because it has the function of adjusting the optical distance so that the optical path can be adjusted.

[0163] The electrode 101 and the electrode 102 can be formed by a sputtering method, a vapor deposition method, a printing method, or a coating method. , MBE (Molecular Beam Epitaxy) method, CVD method, pulse laser The deposition method, ALD (Atomic Layer Deposition) method, etc. are used appropriately. It is possible.

[0164] <Substrate> Furthermore, the light-emitting element according to one embodiment of the present invention may be formed on a substrate made of glass, plastic, or the like. As for the order of fabrication on the substrate, the layers may be stacked in order from the electrode 101 side. They may be stacked in order from the pole 102 side.

[0165] The substrate on which the light-emitting element according to one embodiment of the present invention can be formed is, for example, glass or quartz. Alternatively, a flexible substrate may be used. The substrate is a flexible substrate, such as polycarbonate. Examples of suitable substrates include plastic substrates made of vinyl acetate and polyarylate. Inorganic vapor deposition films can also be used. Any other material may be used as long as it functions as a support in the development. Anything that has the function of protecting the optical element and the optical device may be used.

[0166] For example, in this specification, a light emitting element can be formed using various substrates. The type of substrate is not particularly limited. An example of the substrate is a semiconductor substrate (e.g., a single crystal crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate, gold Metal substrate, stainless steel substrate, substrate with stainless steel foil, tungsten Tungsten substrate, substrate with tungsten foil, flexible substrate, laminated film, fiber Examples of glass substrates include paper or substrate films containing barium-based materials. Examples include borosilicate glass, aluminoborosilicate glass, and soda-lime glass. Examples of flexible substrates, laminated films, base films, etc. include the following: For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) , polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Examples of materials include plastics, such as acrylic resins, and Examples include polypropylene, polyester, polyvinyl fluoride, and polyvinyl chloride. Examples include polyamide, polyimide, aramid, epoxy, Examples include inorganic vapor deposition films and paper.

[0167] 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. After a part or all of a device is completed, it is separated from the substrate and used to transfer it to another substrate. In this case, the light-emitting element can be transferred onto a substrate having poor heat resistance or a flexible substrate. The peeling layer may have a laminated structure of inorganic films, such as a tungsten film and a silicon oxide film. or a structure in which a resin film such as polyimide is formed on a substrate, etc., can be used.

[0168] That is, a light emitting element is formed using a certain substrate, and then the light emitting element is transferred to another substrate. The light emitting element may be disposed on another substrate. In addition to the substrates mentioned above, cellophane substrates, stone substrates, wood substrates, fabric substrates (natural fibers (silk, cotton, Hemp), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate (including cellulose, cupro, rayon, recycled polyester, etc.), leather substrate, rubber substrate, etc. By using these substrates, it is possible to produce light emitting elements that are durable and highly heat resistant. The light emitting element may be a small, lightweight, or thin light emitting element.

[0169] Furthermore, for example, a field effect transistor (FET) is formed on the above-mentioned substrate, and the FET and The light emitting element 150 may be fabricated on the electrically connected electrodes. In this way, an active matrix display device that controls the driving of the light emitting element 150 can be fabricated.

[0170] Note that one embodiment of the present invention has been described in this embodiment. However, the present invention is not limited to these embodiments. That is, various inventive aspects are described in this and other embodiments. Therefore, one embodiment of the present invention is not limited to a specific embodiment. However, one embodiment of the present invention is not limited to this. For example, in some cases or depending on the situation, one embodiment of the present invention may be applied to a light-emitting element. Alternatively, for example, in one embodiment of the present invention, a first organic compound and a second organic compound may be used. The compound has an organic compound and a guest material, and the first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton. and the second organic compound has at least one of a nitrogen-containing five-membered heterocyclic skeleton or a tertiary amine skeleton. However, one embodiment of the present invention is not limited to this. Alternatively, depending on the situation, in one embodiment of the present invention, for example, the second organic compound is not included. Alternatively, the first organic compound may not have a nitrogen-containing six-membered heteroaromatic skeleton. Alternatively, the second organic compound may have a nitrogen-containing five-membered heterocyclic skeleton and a tertiary amine skeleton. Alternatively, for example, in one embodiment of the present invention, a nitrogen-containing five-membered heterocycle having an NH group may be used. the content of the organic compound containing the skeleton or the secondary amine skeleton relative to the first organic compound by weight Although an example where the ratio is 0.03 or less has been shown, one embodiment of the present invention is not limited to this. In some cases, or depending on the circumstances, in one aspect of the present invention, a nitrogen-containing pentaerythritol having an NH group is The content of the organic compound containing a heterocyclic skeleton or a secondary amine skeleton is higher than that of the first organic compound. The weight ratio may be more than 0.03.

[0171] As described above, the structure shown in this embodiment mode can be used in appropriate combination with other embodiment modes. Cut.

[0172] (Embodiment 2) In this embodiment mode, a light-emitting element having a different structure from that of the light-emitting element shown in Embodiment 1 is The light emitting mechanism of the light emitting element will be described below with reference to FIGS. 6 to 8, the same reference numerals as those in FIG. 1(A) denote the same parts having the same functions. In some cases, the hatch pattern is used and the symbols are omitted. Also, parts with similar functions are indicated by The same reference numerals are used and detailed descriptions thereof may be omitted.

[0173] <Configuration example 1 of light-emitting element> FIG. 6A is a schematic cross-sectional view of the light emitting element 250. FIG.

[0174] The light-emitting element 250 shown in FIG. 6A has a pair of electrodes (electrodes 101 and 102) between them. , a plurality of light-emitting units (in FIG. 6A, light-emitting unit 106 and light-emitting unit 1 08). Any one of the plurality of light-emitting units has an EL layer 10 1. That is, the light emitting element 150 shown in FIG. It is preferable that the light emitting element 250 has a plurality of light emitting units. In the light-emitting element 250, the electrode 101 functions as an anode and the electrode 102 functions as a cathode. Assuming this is the case, the following description will be given, but the configuration of the light emitting element 250 may be reversed.

[0175] In addition, in the light-emitting element 250 shown in FIG. 6(A), the light-emitting unit 106 and the light-emitting unit The light-emitting units 106 and 108 are stacked, and a charge generating layer is formed between the light-emitting units 106 and 108. The light-emitting unit 106 and the light-emitting unit 108 have the same structure. For example, the light-emitting unit 106 may have a similar structure to the EL layer 100. It is preferable to use it.

[0176] 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, the knit 106 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer The light-emitting unit 108 also includes an emissive layer 120. In addition to the above, a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0177] The charge generation layer 115 is formed by adding an acceptor material, which is an electron acceptor, to a hole transport material. Even if the electron transport material is an electron donor, a donor material may be added to the electron transport material. Alternatively, both of these structures may be stacked.

[0178] When the charge generation layer 115 contains a composite material of an organic compound and an acceptor substance, the The composite material that can be used for the hole-injection layer 111 shown in Embodiment 1 is used as the composite material. The organic compounds include aromatic amine compounds, carbazole compounds, aromatic carbonized compounds, and the like. Various compounds such as hydrogen and polymer compounds (oligomers, dendrimers, polymers, etc.) are used. As for organic compounds, those with a hole mobility of 1×10 -6 cm 2 / Vs However, it is preferable to use a material having a higher hole transporting property than an electron transporting property. Other materials may be used as long as they are compatible with the organic compound and the acceptor material. The material has excellent carrier injection and carrier transport properties, allowing for low voltage and low current operation. In addition, the anode side of the light-emitting unit is in contact with the charge generating layer 115. In this case, the charge generation layer 115 also serves as a hole injection layer or a hole transport layer for the light-emitting unit. Therefore, the light-emitting unit does not need to have a hole injection layer or a hole transport layer. Alternatively, when the cathode side surface of the light-emitting unit is in contact with the charge generating layer 115, The charge generation layer 115 also serves as an electron injection layer or an electron transport layer for the light-emitting unit. Therefore, the light-emitting unit does not have an electron injection layer or an electron transport layer. is also good.

[0179] The charge generation layer 115 may be a layer containing a composite material of an organic compound and an acceptor substance, or another layer containing a compound of an organic compound and an acceptor substance. For example, the organic EL element may be formed as a laminated structure in which layers made of the organic EL element are combined. A layer including a composite material of a compound and an acceptor substance and a layer including a compound selected from electron donor substances. The compound may be formed by combining a layer containing the compound with a compound having a high electron transporting property. A layer containing a composite material of an organic compound and an acceptor substance and a layer containing a transparent conductive film are combined. It may be formed by combining the above.

[0180] The charge generating layer 115 sandwiched between the light emitting unit 106 and the light emitting unit 108 When a voltage is applied between the electrode 101 and the electrode 102, electrons are injected into one of the light-emitting units, It is sufficient if the hole is injected into the other light-emitting unit. For example, in FIG. 6(A), When a voltage is applied so that the potential of electrode 101 is higher than the potential of electrode 102, The charge generating layer 115 injects electrons into the light-emitting unit 106 and holes into the light-emitting unit 108. Enter.

[0181] From the viewpoint of light extraction efficiency, the charge generation layer 115 is transparent to visible light (specifically, It is preferable that the charge generating layer 115 has a visible light transmittance of 40% or more. The charge generating layer 115 has a lower conductivity than the pair of electrodes (electrodes 101 and 102). It still works.

[0182] By forming the charge generating layer 115 using the above-mentioned materials, when a light emitting layer is laminated, In this case, the increase in the driving voltage can be suppressed.

[0183] In addition, in FIG. 6(A), a light-emitting element having two light-emitting units has been described. However, it can also be applied to light-emitting devices in which three or more light-emitting units are stacked. As shown in the light-emitting element 250, a plurality of light-emitting units are disposed between a pair of electrodes, and a charge generating layer is formed. By separating the layers, high brightness light emission is possible while keeping the current density low. A light-emitting element with a long life and low power consumption can be realized. .

[0184] At least one of the multiple units has the structure shown in the first embodiment. By applying this composition, it is possible to provide a light-emitting element with high luminous efficiency and high reliability. It is possible.

[0185] In this embodiment, the light-emitting layer 170 of the light-emitting unit 106 is the same as that shown in Embodiment 1. The light-emitting element 250 will be described as having a configuration of the light-emitting layer 130. This is preferable as it becomes a light emitting element with high optical efficiency and high reliability.

[0186] The light-emitting layer 120 of the light-emitting unit 108 is formed of a host The material 121 and the guest material 122 are a fluorescent compound. The following will explain this.

[0187] <Light Emitting Mechanism of Light Emitting Layer 120> The light emitting mechanism of the light emitting layer 120 will be explained below.

[0188] The charge injected from the pair of electrodes (electrode 101 and electrode 102) or the charge generating layer 115 The electrons and holes recombine in the light-emitting layer 120 to generate excitons. Since there is a large amount of host material 121 compared to material 122, exciton generation An excited state of the host material 121 is formed.

[0189] An exciton is a pair of carriers (electrons and holes). Therefore, the material in which the excitons are generated is in an excited state.

[0190] When the excited state of the formed host material 121 is a singlet excited state, the host material 12 Singlet excitation energy is transferred from the S1 level of 1 to the S1 level of the guest material 122. As a result, the singlet excited state of the guest material 122 is formed.

[0191] Since the guest material 122 is a fluorescent compound, the guest material 122 is in a singlet excited state. When the state is formed, the guest material 122 quickly emits light. To achieve this, it is preferable that the guest material 122 has a high fluorescence quantum yield. In 122, carriers may recombine and the resulting excited state may be a singlet excited state. The same is true.

[0192] Next, when carrier recombination forms a triplet excited state in the host material 121, In this case, the energy levels of the host material 121 and the guest material 122 are The correlation between the positions is shown in Figure 6(C). The notations and symbols in Figure 6(C) are as follows: The T1 level of the host material 121 is lower than the T1 level of the guest material 122. Since this is preferable, this case is illustrated in FIG. 6C. may be higher than the T1 level of the guest material 122.

[0193] Host (121): Host material 121 Guest (122): Guest material 122 (fluorescent compound) ·S FH : S1 level of the host material 121 T FH : T1 level of the host material 121 ·S FG : S1 level of guest material 122 (fluorescent compound) T FG : T1 level of guest material 122 (fluorescent compound)

[0194] As shown in Figure 6(C), triplet-triplet annihilation (TTA) Triplets generated by carrier recombination are generated by Excitons interact with each other, transferring excitation energy and exchanging spin angular momentum. As a result, the S1 level (S FH ) has an energy of A reaction occurs in which the host material 121 is converted into a singlet exciton (see Figure 6(C) TTA). The singlet excitation energy of FH from a lower energy guest material122 S1 level (S FG ) (see Route E5 in Figure 6(C)), and the guest A singlet excited state of the material 122 is formed, and the guest material 122 emits light.

[0195] When the density of triplet excitons in the light-emitting layer 120 is sufficiently high (for example, 1×10 12 cm -3 In the above, the deactivation of a single triplet exciton is ignored, and the deactivation of two adjacent triplet excitons is considered. Only the reaction by the child can be considered.

[0196] Furthermore, when carriers recombine in the guest material 122 to form a triplet excited state, However, the triplet excited state of the guest material 122 is thermally deactivated, making it difficult to utilize it for light emission. However, the T1 level (T FH ) is the T1 equivalent of guest material 122 Place(T FG ), the triplet excitation energy of guest material 122 is lower than that of guest material 1 22 T1 levels (T FG ) to the T1 level (T FH ) Energy transfer (See route E6 in Figure 6(C)) and then used for TTA.

[0197] That is, the host material 121 converts triplet excitation energy into singlet excitation energy by TTA. It is preferable that the light-emitting layer 120 has a function of converting the generated light into energy. A portion of the triplet excitation energy is converted to singlet excitation energy by TTA in the host material 121. The singlet excitation energy is converted into the guest material 122, and the guest material 122 is transferred to the guest material 122, thereby producing fluorescence. To achieve this, the S1 level (S FH ) is the S1 level (S FG ) is preferable. T1 level (T FH ) is the T1 level (TFG ) lower It is preferable.

[0198] In particular, the T1 level (T FG ) is the T1 level of the host material 121 ( T FH ), the weight ratio of the host material 121 to the guest material 122 is It is preferable that the weight ratio of the guest material 122 is low. The amount is preferably greater than 0 and not greater than 0.05 in terms of weight ratio to the host material 121. By doing so, the probability of carrier recombination in the guest material 122 can be reduced. In addition, the T1 level (T FH ) to the T1 level (T FG ) This can reduce the probability of energy transfer to

[0199] The host material 121 may be composed of a single compound or a plurality of compounds. It may be formed.

[0200] In addition, the light-emitting units 106 and 108 have guest materials with different emission colors. In this case, the emission from the light-emitting layer 120 has a peak in the shorter wavelength side than the emission from the light-emitting layer 170. It is preferable to use a material having a high triplet excitation energy level. The light-emitting element used in this method tends to have a tendency to deteriorate quickly in brightness. By using TA, it is possible to provide a light-emitting element with little deterioration in luminance.

[0201] The light-emitting layer 170 has the same structure as the light-emitting layer 130 shown in the first embodiment and the same structure as the light-emitting layer 120. The configuration may be:

[0202] <Configuration example 2 of light-emitting element> FIG. 7A is a schematic cross-sectional view of the light emitting element 252. FIG.

[0203] The light emitting element 252 shown in FIG. 7A has a pair of electrodes, similar to the light emitting element 250 shown above. A plurality of light-emitting units (in FIG. 7(A), light-emitting elements) are disposed between the electrodes 101 and 102. The light unit 106 and the light-emitting unit 110 are included. At least one light-emitting unit is The light-emitting unit 106 and the light-emitting unit 110 have the same structure as the EL layer 100. may be of the same or different configurations.

[0204] In addition, in the light-emitting element 252 shown in FIG. 7(A), the light-emitting unit 106 and the light-emitting unit The light-emitting unit 106 and the light-emitting unit 110 are stacked together, and a charge generating layer is formed between the light-emitting unit 106 and the light-emitting unit 110. For example, the light-emitting unit 106 may have a structure similar to that of the EL layer 100. It is preferable to use it.

[0205] The light emitting element 252 also includes a light emitting layer 140 and a light emitting layer 170. In addition to the light-emitting layer 170, the knit 106 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer The light-emitting unit 110 also includes a light-emitting layer 140. In addition to the above, a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0206] At least one of the multiple units has the structure shown in the first embodiment. By applying this composition, it is possible to provide a light-emitting element with high luminous efficiency and high reliability. It is possible.

[0207] It is also preferable that the light-emitting layer of the light-emitting unit 110 contains a phosphorescent compound. The light-emitting layer 140 of the light-emitting unit 110 contains a phosphorescent compound, and the light-emitting unit 106 The light-emitting layer 170 preferably has the same structure as the light-emitting layer 130 shown in Embodiment 1. An example of the configuration of the light emitting element 252 in this case will be described below.

[0208] The light-emitting layer 140 of the light-emitting unit 110 is made of a host material 1 as shown in FIG. The host material 141 includes an organic compound 141_ and a guest material 142. The light-emitting layer 140 includes a guest material 141 and an organic compound 141_2. The following description will be given assuming that 2 is a phosphorescent compound.

[0209] <Light Emitting Mechanism of Light Emitting Layer 140> Next, the light emitting mechanism of the light emitting layer 140 will be described below.

[0210] The organic compound 141_1 and the organic compound 141_2 contained in the light-emitting layer 140 form an exciplex. It is preferable to form

[0211] The combination of organic compound 141_1 and organic compound 141_2 forms an exciplex with each other. Any combination is acceptable as long as one of the compounds has a hole transporting property. It is more preferable that the other is a compound having electron transport properties.

[0212] The organic compound 141_1, the organic compound 141_2, and the guest material in the light-emitting layer 140 The correlation of the energy level with 142 is shown in Figure 7(C). The symbols and symbols are as follows: ·Host(141_1): Organic compound 141_1 (host material) ·Host(141_2): Organic compound 141_2 (host material) Guest (142): Guest material 142 (phosphorescent compound) ·S PH1 : S1 level of organic compound 141_1 (host material) T PH1 :T1 level of organic compound 141_1 (host material) ·S PH2 : S1 level of organic compound 141_2 (host material) T PH2 :T1 level of organic compound 141_2 (host material) T PG : T1 level of guest material 142 (phosphorescent compound) ·S PE : S1 level of the exciplex T PE :T1 level of exciplex

[0213] The organic compound 141_1 and the organic compound 141_2 form an exciplex, and the S 1 level (S PE ) and T1 level (T PE ) are adjacent energy levels (Figure 7( C) See route E7).

[0214] Organic compound 141_1 and organic compound 141_2 accept holes and electrons, respectively. Alternatively, when one of the two is excited, it quickly forms an exciplex. Therefore, the exciplex in the light-emitting layer 140 Most of the excited molecules exist as exciplexes. The excited energy levels of exciplexes (S PE Also is T PE ) is a host material (organic compound 141_1 and organic compound 1) that forms an exciplex. 41_2) S1 level (S PH1 and S PH2 ) and therefore has a lower excitation energy This allows the host material 141 to form an excited state. The driving voltage of the element can be reduced.

[0215] And the (S PE ) and (T PE ) and the energy of the guest material 142 (phosphorescent compound) to the T1 level to obtain light emission (Figure 7(C) Route E8, E 9).

[0216] In addition, the T1 level of the exciplex (T PE ) is the T1 level (T PG )twist By doing so, the singlet excitation energy and and triplet excitation energy to the S1 level (S PE ) and T1 level (T PE )mosquito The T1 level (T PG ) can transfer energy to

[0217] In addition, in order to efficiently transfer excitation energy from the exciplex to the guest material 142, , the T1 level of the exciplex (T PE ) are each organic compound that forms an exciplex (organic compound 14 T1 levels (T PH1 and T PH2 ) or It is preferable that the organic compound (organic compound 141_1 and organic Compound 141_2) is less likely to quench the triplet excitation energy of the exciplex. Energy transfer from the exciplex to the guest material 142 occurs efficiently.

[0218] In addition, the organic compound 141_1 and the organic compound 141_2 efficiently form an exciplex. In order to achieve this, the HOMO level of one of the organic compounds 141_1 and 141_2 must be The HOMO level is higher than the other, and the LUMO level of one is higher than the LUMO level of the other. For example, the organic compound 141_1 has a hole transporting property, and the organic compound 141_2 has a hole transporting property. When the organic compound 141_1 has electron transport properties, the HOMO level of the organic compound 141_2 It is preferable that the LUMO level of the organic compound 141_1 is higher than the HOMO level of the organic compound 141_2. It is preferable that the LUMO level of the organic compound 141_2 is higher than that of the organic compound 141_3. When the organic compound 141_1 has a hole transporting property and the organic compound 141_2 has an electron transporting property, the organic compound 141_1 The HOMO level of 41_2 is preferably higher than the HOMO level of the organic compound 141_1. , the LUMO level of organic compound 141_2 is higher than the LUMO level of organic compound 141_1. Specifically, it is preferable that the HOMO level of the organic compound 141_1 and the HOMO level of the organic compound 141 The energy difference between the HOMO level of _2 is preferably 0.05 eV or more, and more preferably The electron transport potential is preferably 0.1 eV or more, and more preferably 0.2 eV or more. The energy difference between the LUMO level of organic compound 141_1 and the LUMO level of organic compound 141_2 is Preferably, it is 0.05 eV or more, more preferably 0.1 eV or more, and even more preferably Preferably, it is 0.2 eV or more.

[0219] In addition, the combination of organic compound 141_1 and organic compound 141_2 has hole transport properties. When a compound having electron transport properties is used in combination with a compound having electron transport properties, the mixing ratio Specifically, the carrier balance can be easily controlled by using a material having hole transport properties. The compound having electron transport properties:compound having electron transport properties is preferably in the range of 1:9 to 9:1 (weight ratio). In addition, by having this configuration, the carrier balance can be easily controlled. In addition, the carrier recombination region can be easily controlled.

[0220] <Energy transfer mechanism> Next, the control of the energy transfer process between the host material 141 and the guest material 142 The mechanism of energy transfer between molecules is the Förster mechanism (bipolar Two mechanisms have been proposed: the electron-dipole interaction (electron-dipole interaction) and the Dexter mechanism (electron exchange interaction). Here, energy transfer between the host material 141 and the guest material 142 is The process is similar when the host material 141 is an exciplex.

[0221] <Förster mechanism> In the Förster mechanism, energy transfer does not require direct contact between molecules, but occurs via the host Energy transfer occurs through the resonance phenomenon of dipole vibration between the material 141 and the guest material 142. The host material 141 transfers energy to the guest material 142 due to the resonance phenomenon of the dipole vibration. The excited host material 141 returns to the ground state, and the guest material 14 2 becomes excited. The rate constant of the Förster mechanism is k h*→g is shown in formula (1) .

[0222]

number

[0223] In formula (1), ν represents the frequency, and f' h (ν) is the standard of the host material 141 The emission spectrum (or the fluorescence spectrum when discussing energy transfer from the singlet excited state) spectrum, and phosphorescence spectrum when discussing energy transfer from triplet excited states), ε g (ν) represents the molar extinction coefficient of the guest material 142, N represents Avogadro's number, and n represents the refractive index of the medium, and R represents the intermolecular distance between the host material 141 and the guest material 142. where τ represents the measured lifetime of the excited state (fluorescence lifetime or phosphorescence lifetime), and c represents the speed of light. , φ is the luminescence quantum yield (fluorescence quantum yield when discussing energy transfer from the singlet excited state) represents the phosphorescence quantum yield when discussing energy transfer from the triplet excited state, and K 2 teeth , a coefficient (between 0 and 142) that represents the orientation of the transition dipole moments of the host material 141 and the guest material 142. In the case of random orientation, K 2 =2 / 3.

[0224] Dexter Mechanism In the Dexter mechanism, the host material 141 and the guest material 142 are bonded together, causing orbital overlap. The electrons in the excited host material 141 and the ground state guest material 14 Energy transfer occurs through the exchange of electrons with 2. The rate constant for the Dexter mechanism is k h*→g is shown in equation (2).

[0225]

number

[0226] In equation (2), h is Planck's constant, and K is a constant with the dimension of energy. where ν represents the frequency and f' h (ν) is the normalized emission spectrum of the host material 141. Spectra (fluorescence spectrum when discussing energy transfer from singlet excited states, triplet When discussing energy transfer from an excited state, it represents the phosphorescence spectrum, and ε' g (ν) is , represents the normalized absorption spectrum of the guest material 142, L represents the effective molecular radius, R represents the intermolecular distance between the host material 141 and the guest material 142 .

[0227] Here, the energy transfer efficiency φ from the host material 141 to the guest material 142 ET is a number It is expressed by equation (3). r The emission process of the host material 141 (energy from the singlet excited state) When discussing energy transfer, we use fluorescence; when discussing energy transfer from triplet excited states, we use phosphorus. represents the rate constant of photon transport, k n is the non-radiative process (thermal deactivation and intersystem crossing) of the host material 141. represents the rate constant, and τ represents the measured lifetime of the excited state of the host material 141.

[0228]

number

[0229] From equation (3), the energy transfer efficiency φ ET To increase the energy transfer rate, Degree constant k h*→g By increasing the rate constant k r +k n (=1 / τ) is relatively You know the smaller the better.

[0230] <Concept for enhancing energy transfer> In the energy transfer by the Förster mechanism, the energy transfer efficiency φ ET is Photon quantum yield φ (fluorescence quantum yield when discussing energy transfer from a singlet excited state, When discussing energy transfer from triplet excited states, a higher phosphorescence quantum yield is better. In addition, the emission spectrum of the host material 141 (which discusses energy transfer from the singlet excited state) The fluorescence spectrum in the case of the guest material 142 and the absorption spectrum (from the singlet ground state to the triplet state) It is preferable that the overlap with the absorption corresponding to the transition to the first excited state is large. It is also preferable that the molar absorption coefficient of the host material 142 is high. This means that the spectrum overlaps with the absorption band appearing on the longest wavelength side of the guest material 142. do.

[0231] In addition, in the energy transfer by the Dexter mechanism, the rate constant k h*→g Enlarge In this study, the emission spectrum of the host material 141 (energy transfer from the singlet excited state) was discussed. When discussing energy transfer from triplet excited states, we use the fluorescence spectrum. Absorption spectra of the 142 (singlet ground state to triplet excited state) and guest material Therefore, the efficiency of energy transfer is The optimization is performed on the emission spectrum of the host material 141 and the longest wavelength side of the guest material 142. This is achieved by the overlap of the absorption bands of the

[0232] Similar to the energy transfer from the host material 141 to the guest material 142, an exciplex The energy transfer process from the ion to the guest material142 was also investigated using the Förster mechanism and the Deca- Energy transfer occurs via both mechanisms of the star mechanism.

[0233] That is, the host material 141 is capable of efficiently transferring energy to the guest material 142. 14 organic compounds that form exciplexes that function as energy donors 1_1 and organic compound 141_2. Organic compound 141_1 and organic compound 1 The exciplex formed by 41_2 is the organic compound 141_1 and the organic compound 141_2 alone. Therefore, the excitation energy of the light-emitting element can be lower than that of the excited state of the light-emitting element. The pressure can be reduced.

[0234] Furthermore, the T of the guest material 142, which acts as an energy acceptor, is calculated from the S1 level of the exciplex. To facilitate the energy transfer to the 1st level, the emission spectrum of the exciplex and the It is preferable that the absorption band of the photoresist material 142 overlaps with the absorption band appearing on the longest wavelength side (lowest energy side). By doing so, it is possible to increase the generation efficiency of the triplet excited state of the guest material 142. do.

[0235] The exciplex generated in the light-emitting layer 140 has a singlet excited energy level and a triplet excited energy level. The emission spectrum of exciplexes is characterized by the close proximity of the excited energy levels. By overlapping the absorption bands of the guest material 142 and the guest material 142, which appear at the longest wavelength (lowest energy side), , the triplet excited energy level of the exciplex is converted to that of the guest material 142. This also makes it easier for energy transfer to occur.

[0236] By configuring the light-emitting layer 140 as described above, the guest material 142 (phosphorescent This makes it possible to efficiently obtain light emission from the compound.

[0237] The above-described routes E7 to E9 are referred to as ExTET (Ex It is sometimes called plex-triplet energy transfer. In other words, the light-emitting layer 140 transfers the excitation energy from the exciplex to the guest material 142. In this case, it is not necessarily T PE From S PE High efficiency of reverse intersystem crossing is required No, S PE The quantum yield of light emission from the material does not need to be high, so a wide range of materials can be selected. It becomes possible.

[0238] The light-emitting layer 170 has the same structure as the light-emitting layer 130 shown in the first embodiment and the same structure as the light-emitting layer 140. The configuration may be:

[0239] In each of the above configurations, the light-emitting unit 106 and the light-emitting unit 108, or the light-emitting The emission colors of the guest materials used in the unit 106 and the light-emitting unit 110 include: The light-emitting units 106 and 108 may be the same or different. Alternatively, the light emitting unit 106 and the light emitting unit 110 may emit light of the same color. When the light-emitting element 250 and the light-emitting element 252 have a guest material having a light-emitting function, the light-emitting element 250 and the light-emitting element 252 can emit a small amount of current. This is preferable as a light-emitting element that exhibits high light-emitting luminance. The unit 108, or the light emitting unit 106 and the light emitting unit 110, are of different colors. When a guest material having a function of emitting light is included, the light-emitting element 250 and the light-emitting element 252 In this case, the light-emitting layer 120 and the light-emitting layer 170 are preferably light-emitting elements that emit multicolor light. or either one or both of light-emitting layer 140 and light-emitting layer 170 By using a plurality of light-emitting materials with different emission wavelengths for both the light-emitting element 250 and the The emission spectrum exhibited by the light emitting element 252 is a composite of emission having different emission peaks. The resulting light has an emission spectrum with at least two maxima.

[0240] The above-mentioned structure is also suitable for obtaining white light emission. Alternatively, by making the light from the light-emitting layer 140 and the light-emitting layer 170 complementary in color, white light can be obtained. In particular, white light with high color rendering, or at least red and green light, can be obtained. It is preferable to select the guest material so that it emits light having blue and red.

[0241] In addition, at least one of the light-emitting layer 120, the light-emitting layer 140, and the light-emitting layer 170 is layered. It may be further divided into layers, and each divided layer may contain a different light-emitting material. That is, at least one of the light-emitting layers 120, 140, and 170 is composed of two or more layers. It can also be configured with multiple layers. For example, the first and second light-emitting layers can be configured as hole transport layers. When the light-emitting layers are laminated in order from the first layer side, the first light-emitting layer has hole transport properties as a host material. and a material having an electron transporting property is used as a host material for the second light-emitting layer. In this case, the light-emitting materials of the first light-emitting layer and the second light-emitting layer are the same material. The materials may be the same or different, and may be materials that have the function of emitting light of the same color. The materials may be materials that have the function of emitting light of different colors. By using a structure that has multiple luminescent materials with the function of emitting light, it is possible to emit light in three primary colors or four or more colors. It is also possible to obtain white light emission with high color rendering properties.

[0242] <Configuration example 3 of light-emitting element> Next, regarding examples of configurations different from those of the light-emitting elements shown in FIGS. 6 and 7, FIGS. 8(A), 8(B), and 8(C) are shown. The following explanation will be given using

[0243] FIG. 8A is a schematic cross-sectional view of the light emitting element 254. FIG.

[0244] The light-emitting element 254 shown in FIG. 8A has a pair of electrodes (electrodes 101 and 102) between them. The EL layer 100 is sandwiched between the electrodes 101 and 102. The following description will be given assuming that the electrode 101 functions as a cathode and the electrode 102 functions as a cathode. The configuration of 4 may be reversed.

[0245] The EL layer 100 also includes a light-emitting layer 180, which is a light-emitting layer 120 and a light-emitting layer 130. In the light-emitting element 254, the EL layer 100 is a light-emitting layer In addition, a hole injection layer 111, a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119 However, these laminated structures are merely examples, and the EL layer 1 in the light emitting element 254 The structure of EL layer 100 is not limited to these. For example, the stacking order of the above layers in EL layer 100 is Alternatively, the EL layer 100 may be provided with a functional layer other than the above layers. The functional layer may have a function of reducing the hole or electron injection barrier, a function of reducing the hole or electron injection barrier, or a function of reducing the hole or electron injection barrier. The function of improving the transportability of electrons, the function of inhibiting the transportability of holes or electrons, The configuration may have a function of generating the signal.

[0246] As shown in FIG. 8B, the light-emitting layer 120 is made of a host material 121 and a guest material 122. The light-emitting layer 140 contains a host material 141 and a guest material 142. The host material 141 includes an organic compound 141_1 and an organic compound 141_2. The guest material 122 is a fluorescent compound, and the guest material 142 is a phosphorescent compound. This is explained below.

[0247] At least one of the light-emitting layers 120 and 140 may be formed using the light-emitting layer shown in the first embodiment. It is preferable to have an optical layer 130 configuration.

[0248] <Light-emitting mechanism of the light-emitting layer 180> The light-emitting mechanism of the light-emitting layer 120 is the same as that of the light-emitting layer 120 shown in FIG. 6(B)(C). The light emitting mechanism of the light emitting layer 140 is the same as that of the light emitting layer 1 shown in FIGS. It has the same light-emitting mechanism as 40.

[0249] As shown in FIG. 8(A), the light-emitting layer 120 and the light-emitting layer 140 are in contact with each other. In this case, light is emitted from the exciplex of the light-emitting layer 140 at the interface between the light-emitting layer 120 and the light-emitting layer 140. Energy transfer (especially triplet excitation energy) from the optical layer 120 to the host material 121 Even if the triplet excitation energy is converted into light emission in the light-emitting layer 120, the triplet excitation energy is converted into light emission. can be converted.

[0250] The T1 level of the host material 121 of the light-emitting layer 120 is higher than that of the organic compound contained in the light-emitting layer 140. It is preferable that the T1 level of the light-emitting layer is lower than the T1 level of the organic compound 141_1 and the organic compound 141_2. In 120, the S1 level of the host material 121 is the S1 level of the guest material 122 (fluorescent compound). The T1 level of the host material 121 is higher than the T1 level of the guest material 122 (fluorescent compound). It is preferable that the T1 level is lower than the T1 level of the compound.

[0251] Specifically, when TTA is used for the light-emitting layer 120 and ExTET is used for the light-emitting layer 140, The correlation of the energy levels is shown in Figure 8(C). The notations and symbols in Figure 8(C) are as follows: It is as follows. Fluorescence EML(120): Emitting layer 120 (fluorescent emitting layer) Phosphorescence EML(140): Emitting layer 140 (phosphorescent emitting layer) Host (121): Host material 121 Guest (122): Guest material 122 (fluorescent compound) ·Host(141_1): Host material (organic compound 141_1) Guest (142): Guest material 142 (phosphorescent compound) ·Exciplex: Excitation complex (organic compound 141_1 and organic compound 141_2) ·S FH : S1 level of the host material 121 T FH : T1 level of the host material 121 ·S FG : S1 level of guest material 122 (fluorescent compound) T FG : T1 level of guest material 122 (fluorescent compound) ·S PH : S1 level of the host material (organic compound 141_1) T PH : T1 level of the host material (organic compound 141_1) T PG : T1 level of guest material 142 (phosphorescent compound) ·S E : S1 level of the exciplex T E :T1 level of exciplex

[0252] As shown in Figure 8(C), exciplexes exist only in the excited state, so The exciton diffusion between the exciplex and the nucleus is difficult. E , T E ) is the organic compound 141_1 of the light-emitting layer 140 (i.e., the host material of the phosphorescent compound). The excited energy level (S PH , T PH ), so the exciplex is converted to organic compound 14 In other words, there is no diffusion of energy into the phosphorescent light-emitting layer (light-emitting layer 140). In this case, the exciton diffusion length of the exciplex is short, so the efficiency of the phosphorescent light-emitting layer (light-emitting layer 140) is maintained. In addition, the fluorescent light-emitting layer (light-emitting layer 120) and the phosphorescent light-emitting layer (light-emitting layer 140) At the interface, a part of the triplet excitation energy of the exciplex of the phosphorescent emitting layer (emitting layer 140) Even if the phosphor diffuses into the fluorescent light-emitting layer (light-emitting layer 120), the phosphor The triplet excitation energy of the light-emitting layer 120 is converted into light emission through TTA. This makes it possible to reduce energy loss.

[0253] As described above, the light-emitting device 254 uses ExTET for the light-emitting layer 140 and By using TTA in 20, energy loss is reduced, resulting in high luminous efficiency. As shown in the light-emitting element 254, the light-emitting layer 120 and the light-emitting layer 140 are in contact with each other, the energy loss is reduced and E The number of L layers 100 can be reduced. Therefore, the light emitting device can be manufactured at low cost. It can be said that:

[0254] The light-emitting layer 120 and the light-emitting layer 140 may not be in contact with each other. In this case, the organic compound 141_1, the organic compound 141_2, or The guest material 142 (phosphorescent compound) is excited to the host material 121 in the light-emitting layer 120. , or energy transfer to the guest material 122 (fluorescent compound) via the Dexter mechanism ( In particular, triplet energy transfer can be prevented. The layer provided between the substrate 40 and the substrate 40 may have a thickness of about several nm. If it is equal to or less, an increase in the driving voltage can be suppressed, which is preferable.

[0255] The layer provided between the light-emitting layer 120 and the light-emitting layer 140 may be made of a single material. The layer may contain both a hole transporting material and an electron transporting material. In this case, a bipolar material may be used. The ratio of the mobility of a hole transport material to that of an electron transport material is 100 or less. Alternatively, at least one of them may be a host material for the light-emitting layer 140. Even if it is formed from the same material as the substrate material (organic compound 141_1 or organic compound 141_2), This makes it easier to fabricate the light-emitting device and reduces the driving voltage. The hole transporting material and the electron transporting material may form an exciplex, which generates an exciton Specifically, the host material (organic compound) of the light-emitting layer 140 can be effectively prevented from diffusing. Substance 141_1 or organic compound 141_2) or guest material 142 (phosphorescent compound) The excited state of the light-emitting layer 120 is converted into the host material 121 or the guest material 122 (fluorescent This can prevent energy transfer to the ion exchange reaction (ion exchange reaction).

[0256] In the light-emitting element 254, the light-emitting layer 120 is on the hole transport layer 112 side, and the light-emitting layer 140 is on the hole transport layer 112 side. However, the light-emitting element of one embodiment of the present invention is not limited to this. The light-emitting layer 120 is on the electron transport layer 118 side, and the light-emitting layer 140 is on the hole transport layer 112 side. It's okay.

[0257] In the light emitting element 254, the recombination region of the carriers is formed with a certain degree of distribution. Therefore, it is preferable that the light-emitting layer 120 or the light-emitting layer 140 has an appropriate carrier. The guest material 142 (phosphorescent material) contained in the light-emitting layer 140 preferably has an absorptive property. It is preferable that the gate electrode of the light-emitting layer 120 has an electron trapping property. It is preferable that the layer material 122 (fluorescent compound) has hole trapping properties.

[0258] The light emitted from the light-emitting layer 120 has a peak at a shorter wavelength than the light emitted from the light-emitting layer 140. It is preferable that the light emitting element has a structure having a short wavelength light emitting element. Optical elements tend to deteriorate quickly in brightness. Therefore, by using fluorescent light for short wavelength light, As a result, a light-emitting element with little deterioration in luminance can be provided.

[0259] Furthermore, by obtaining light of different wavelengths from the light-emitting layer 120 and the light-emitting layer 140, multicolor The light-emitting element may have different emission peaks in the emission spectrum. Since the emitted light is synthesized, the emission spectrum has at least two maxima. .

[0260] The above structure is also suitable for obtaining white light emission. By making the light from the two fluorescent materials complementary to each other, white light can be emitted.

[0261] In addition, one or both of the light-emitting layer 120 and the light-emitting layer 140 may have different emission wavelengths. By using multiple luminescent materials, it is possible to produce high color rendering with three primary colors or four or more luminescent colors. In this case, the light-emitting layer is further divided into layers, and the divided layers are Each layer may contain a different light-emitting material.

[0262] <Examples of materials that can be used for the light-emitting layer> Next, materials that can be used for the light-emitting layer 120, the light-emitting layer 140, and the light-emitting layer 170 will be described. The following explains the details.

[0263] <Materials that can be used for the light-emitting layer 120> In the light-emitting layer 120, the host material 121 is present in the largest amount by weight, and the guest material 122 The fluorescent compound is dispersed in the host material 121. The S1 level of the host material 121 is , which is higher than the S1 level of the guest material 122 (fluorescent compound) and the T1 level of the host material 121. The level is preferably lower than the T1 level of the guest material 122 (fluorescent compound).

[0264] In the light-emitting layer 120, the guest material 122 is not particularly limited, but may be anthracene. derivatives, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives, Rylene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxazine Derivatives, phenothiazine derivatives, etc. are preferred. The fluorescent compounds exemplified above can be used as the guest material 132.

[0265] In the light-emitting layer 120, materials that can be used as the host material 121 include: Although there is no particular limitation, 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-quinolinolato)(4-phenylphenolato) ) Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II)( Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) ( abbreviation: ZnBTZ), metal complexes such as 2-(4-biphenylyl)-5-(4-tert- butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5 -(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene 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-benzimidazoline) TPBI), bathophenanthroline (BPhen), bathocuproline BCP, 9-[4-(5-phenyl-1,3,4-oxadiazole-2- Heterocyclic compounds such as 4,4-phenyl-9H-carbazole (abbreviation: CO11), '-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB) is 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 Aromatic amine compounds such as benzophenone (BSPB) are also suitable. Nanthrene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g,p]chrysene derivatives Condensed polycyclic aromatic compounds such as 9,10-diphenylanthracene are specifically exemplified. (abbreviation: DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-anthracene] tolyl)phenyl]-9H-carbazol-3-amine (abbreviation: CzA1PA), 4-( 10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), 4-(9 H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)tripheny YGAPA, N,9-diphenyl-N-[4-(10-phenyl-9 -anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), N ,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl {phenyl}-9H-carbazol-3-amine (abbreviation: PCAPBA), N,9-diphenyl N-(9,10-diphenyl-2-anthryl)-9H-carbazol-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 0-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)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'-bianthryl (abbreviation: BANT), 9,9'-(styryl) 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 1,1',1''-(phenyl-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), Benzene-1,3,5-triyl)tripylene (abbreviation: TPB3) In addition, from among these and known substances, the energy gap of the guest material 122 can be If one or more materials with a larger energy gap than the good.

[0266] The light-emitting layer 120 may be composed of two or more layers. When the light-emitting layer 120 is formed by laminating the first light-emitting layer and the second light-emitting layer in this order from the hole transport layer side, a substance having hole transport properties is used as a host material for the first light-emitting layer, and a substance having hole transport properties is used as a host material for the second light-emitting layer For example, a substance having an electron transport property is used as the light emitting element.

[0267] In the light-emitting layer 120, the host material 121 is composed of one kind of compound. Alternatively, the light-emitting layer 120 may be made up of a single compound or a plurality of compounds. The layer may contain materials other than the host material 121 and the guest material 122.

[0268] Furthermore, the light-emitting layer 120 may have the configuration of the light-emitting layer 130 shown in the first embodiment. In this case, the host material 131 and the guest material 132 (fluorescent compound) shown in Embodiment 1 are It is preferable to use

[0269] <Materials that can be used for the light-emitting layer 140> In the light-emitting layer 140, the host material 141 is present in the largest amount by weight, and the guest material 142 The phosphorescent compound is dispersed in the host material 141. The T1 level of 1 (organic compound 141_1 and organic compound 141_2) is It is preferable that the T1 level is higher than that of the T1 level of the ion beam.

[0270] Organic compounds 141_1 include zinc and aluminum metal complexes, as well as oxadiazo derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzyl Dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidin derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives Other examples include aromatic amines and carbazole derivatives. Specifically, the electron transporting material and the hole transporting material shown in Embodiment 1 are used. It is possible.

[0271] The organic compound 141_2 is a compound that can form an exciplex with the organic compound 141_1. Specifically, for example, the combination of the electron transporting material and the hole transporting material shown in the first embodiment is preferable. A transport material can be used. In this case, organic compound 141_1 and organic compound 141 The emission peak of the exciplex formed with _2 is triplet of the guest material 142 (phosphorescent compound). Term MLCT (Metal to Ligand Charge Transfer) transition The absorption band of organic compound 141_ is overlapped with that of the longest wavelength side, more specifically, 1, organic compound 141_2, and guest material 142 (phosphorescent compound) can be selected. This is preferable. It is possible to obtain a light-emitting device with dramatically improved luminous efficiency. However, when a thermally activated delayed fluorescent compound is used instead of a phosphorescent compound, the longest wavelength The long absorption band is preferably a singlet absorption band.

[0272] The guest material 142 (phosphorescent compound) is an iridium, rhodium, or platinum-based Organometallic complexes or metal complexes are mentioned, among which organic iridium complexes, e.g., iridium The orthometalated ammonium complex is preferred. The orthometalated ligand is 4H-triazolium. 1H-triazole ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidine ligands Examples of the metal complexes include quinazine, pyrazine, and isoquinoline ligands. Examples of the platinum complex include a platinum complex having a porphyrin ligand. The phosphorescent compound exemplified as the guest material 132 in Embodiment 1 can be used. Cut.

[0273] The light-emitting material contained in the light-emitting layer 140 is a material capable of converting triplet excitation energy into light. The material capable of converting the triplet excitation energy into light emission is a phosphorescent material. In addition to the compounds, thermally activated delayed fluorescent compounds are also included. The part may be read as a thermally activated delayed fluorescent compound.

[0274] In addition, materials that exhibit thermally activated delayed fluorescence can be independently converted from triplet excited states by reverse intersystem crossing. The material may be capable of generating a doublet excited state, or may be an exciplex (or It may be made up of multiple materials that form a composite (also called an exciplex).

[0275] When the thermally activated delayed fluorescent compound is composed of one kind of material, specifically, The thermally activated delayed fluorescent compound shown in Form 1 can be used.

[0276] In addition, when a thermally activated delayed fluorescent compound is used as a host material, it forms an exciplex. It is preferable to use two types of compounds in combination. In this case, the exciplex shown above The combination of compounds that readily accept electrons and compounds that readily accept holes forms a It is particularly preferred to use the material.

[0277] Furthermore, the light-emitting layer 140 may have the same configuration as the light-emitting layer 130 shown in the first embodiment. In this case, the host material 131 and the guest material 132 (phosphorescent compound) shown in Embodiment 1 are It is preferable to use

[0278] <Materials that can be used for the light-emitting layer 170> The light-emitting layer 170 can be made of any of the materials used for the light-emitting layer in the first embodiment. By using materials that can be used in the light-emitting device, a light-emitting device with high luminous efficiency can be created. It can be manufactured.

[0279] In addition, the light emission colors of the light emitting materials contained in the light emitting layers 120, 140, and 170 are There is no limitation, and they may be the same or different. The light emitted from each is mixed. For example, if the colors of the two lights are complementary to each other, The element can provide white light. The emission peak wavelength of the luminescent material contained in the luminescent layer 170 is shorter than that of the luminescent material contained in the luminescent layer 170. It is preferable that:

[0280] The light-emitting units 106, 108, 110, and the charge generating The layer 115 can be formed by a deposition method (including a vacuum deposition method), an inkjet method, a coating method, a gravure printing method, etc. It can be formed by the method described above.

[0281] The structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there.

[0282] (Embodiment 3) In this embodiment mode, a light-emitting element having a different structure from those shown in Embodiment Modes 1 and 2 will be described. An example of this will be described below with reference to FIGS.

[0283] <Configuration example 1 of light-emitting element> 9(A) and 9(B) are cross-sectional views showing a light-emitting element of one embodiment of the present invention. In (B), the parts having the same functions as those shown in (A) are marked with the same hatching. In addition, parts with similar functions will be marked with similar symbols. In some cases, symbols are used and detailed descriptions thereof are omitted.

[0284] The light emitting element 260a and the light emitting element 260b shown in FIGS. 9(A) and 9(B) emit light toward the substrate 200. The light emitting element may be a bottom emission type light emitting element that extracts light from the substrate 200. It may also be a top emission type light emitting element that extracts light in the opposite direction. Note that one embodiment of the present invention is not limited to this. Light emitted from the light-emitting element may be projected from above and below the substrate 200. It may also be a dual emission type light emitting element in which light is extracted both upward and downward. .

[0285] When the light emitting element 260a and the light emitting element 260b are bottom emission type, the electrode 1 The electrode 101 preferably has a function of transmitting light. Alternatively, the light emitting element 260a and the light emitting element 260b may have a function of In the case of a top emission type, the electrode 101 preferably has a function of reflecting light. In addition, the electrode 102 preferably has a function of transmitting light.

[0286] The light emitting element 260a and the light emitting element 260b are formed by providing an electrode 101 and an electrode 102 on a substrate 200. Between the electrode 101 and the electrode 102, there is provided a light-emitting layer 123B and a light-emitting layer 123C. G and a light-emitting layer 123R. Also, the light-emitting layer 123B has a hole injection layer 111, a hole transport layer 112, It has an electron transport layer 113 and an electron injection layer 114 .

[0287] The light-emitting element 260b includes a conductive layer 101a and a conductive The conductive layer 101b is located above the conductive layer 101a, and the conductive layer 101c is located below the conductive layer 101a. That is, in the light emitting element 260b, the conductive layer 101a is made up of the conductive layer 101b and the conductive layer 101c. It has a sandwiched electrode 101 configuration.

[0288] In the light emitting element 260b, the conductive layer 101b and the conductive layer 101c are made of different materials. The conductive layer 101b and the conductive layer 101c may be made of the same material. When the electrodes 101 are made of the same conductive material, the electrodes 101 are formed by an etching process. This is preferable because it makes pattern formation easier.

[0289] In the light-emitting element 260b, the conductive layer 101b or the conductive layer 101c A configuration having only one of them may also be used.

[0290] The conductive layers 101a, 101b, and 101c of the electrode 101 are each The same structure and material as the electrode 101 or the electrode 102 shown in the first embodiment can be used. Cut.

[0291] In FIGS. 9(A) and 9(B), the region 221B sandwiched between the electrode 101 and the electrode 102, A partition wall 145 is provided between the region 221G and the region 221R. The partition wall 145 has insulating properties. The partition 145 covers the edge of the electrode 101 and has an opening that overlaps with the electrode. By providing 145, the electrodes 101 on the substrate 200 in each region are divided into islands. It becomes possible to separate.

[0292] The light-emitting layer 123B and the light-emitting layer 123G are mutually separated in the region where they overlap with the partition wall 145. The light-emitting layer 123G and the light-emitting layer 123R may have an overlapping region. In the region overlapping with the wall 145, there may be a region overlapping with each other. The light-emitting layer 23R and the light-emitting layer 123B overlap each other in the region where they overlap with the partition wall 145. It may have.

[0293] The partition wall 145 may be formed using an inorganic or organic material as long as it has insulating properties. The inorganic material may be silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, or the like. Examples of the organic material include silicon, aluminum oxide, and aluminum nitride. For example, photosensitive resin materials such as acrylic resin or polyimide resin can be used.

[0294] The silicon oxynitride film is a film whose composition contains more oxygen than nitrogen. Preferably, oxygen is 55 atomic % or more and 65 atomic % or less, and nitrogen is 1 atomic % or more and 20 atomic % or less. Silicon is 25 atomic % or more and 35 atomic % or less, and hydrogen is 0.1 atomic % or more and 10 atomic % or less The silicon nitride oxide film is a film that contains more nitrogen than oxygen as its composition. It refers to a film with a high content of nitrogen, preferably 55 atomic % to 65 atomic % and 100 atomic % of oxygen. % or more and 20 atomic % or less, silicon is 25 atomic % or more and 35 atomic % or less, hydrogen is 0.1 atomic % or more This refers to a film containing this element in a concentration range of 1 atomic % to 10 atomic %.

[0295] The light-emitting layers 123R, 123G, and 123B each exhibit a different color. For example, the light-emitting layer 123R may have a red light-emitting material. By including a light-emitting material having a function of emitting red light, the region 221R emits red light, and the light-emitting layer 12 Since the region 3G has a light-emitting material having a function of emitting green light, the region 221G emits green light. The light-emitting layer 123B contains a light-emitting material that exhibits blue color. B emits blue light. By using 0b in the pixels of a display device, a display device capable of full color display can be manufactured. The thickness of each light-emitting layer may be the same or different. good.

[0296] In addition, any one or more of the light-emitting layer 123B, the light-emitting layer 123G, and the light-emitting layer 123R This light-emitting layer preferably has the configuration of the light-emitting layer 130 shown in the first embodiment. By this, a light-emitting element with high luminous efficiency and high reliability can be manufactured. .

[0297] In addition, any one or more of the light-emitting layer 123B, the light-emitting layer 123G, and the light-emitting layer 123R The light-emitting layer may have a structure in which two or more layers are laminated.

[0298] As described above, at least one light-emitting layer has the structure of the light-emitting layer shown in Embodiment 1, The light emitting element 260a or 260b having the light emitting layer is used in a pixel of a display device. As a result, a display device with high luminous efficiency and high reliability can be manufactured. That is, a display device having the light emitting element 260a or the light emitting element 260b can reduce power consumption. It is possible.

[0299] In addition, if an optical element (for example, a color filter, By providing a polarizing plate, an anti-reflection film, etc., the color purity of the light emitting element 260a and the light emitting element 260b can be improved. Therefore, the light emitting element 260a or the light emitting element 260b is effectively used. Alternatively, the color purity of the display device can be improved. Therefore, the light emitting element 260a or the light emitting element 260b can be prevented from reflecting external light. The contrast ratio of a display device having the element 260b can be increased.

[0300] Other configurations of the light emitting element 260a and the light emitting element 260b are the same as those in the embodiment. The structures of the light-emitting elements in Embodiments 1 and 2 may be referred to.

[0301] <Configuration example 2 of light-emitting element> Next, regarding examples of configurations different from those of the light-emitting element shown in FIGS. 9(A) and 9(B), The following explanation will be given using

[0302] 10A and 10B are cross-sectional views illustrating a light-emitting element of one embodiment of the present invention. In (A) and (B), the parts having the same functions as those shown in Figs. 9(A) and (B) are designated by the same symbols. In some cases, the hatch pattern will be the same and the symbols will be omitted. are denoted by the same reference numerals, and detailed explanations thereof may be omitted.

[0303] 10(A) and 10(B) show examples of the structure of a light-emitting element having a light-emitting layer between a pair of electrodes. The light emitting element 262a shown in FIG. 10(A) is a top-emitting element that extracts light in the direction opposite to the substrate 200. The (top emission) type light emitting element 262b shown in FIG. 10(B) is a light emitting element having a substrate 2 It is a bottom emission type light emitting element that extracts light from the 00 side. One embodiment of the present invention is not limited to this, and light emitted by the light emitting element may be emitted from the substrate 20 on which the light emitting element is formed. It may be a dual emission type that emits light from both above and below the stomach.

[0304] The light emitting element 262a and the light emitting element 262b are formed by providing an electrode 101 and an electrode 102 on a substrate 200. , electrode 103, and electrode 104. Also, between electrode 101 and electrode 102, and At least a light-emitting layer is formed between the electrode 102 and the electrode 103 and between the electrode 102 and the electrode 104. The organic electroluminescent device has a layer 170, a light-emitting layer 190, and a charge-generating layer 115. The organic electroluminescent device also has a hole-injecting layer 111 and a , a hole transport layer 112, an electron transport layer 113, an electron injection layer 114, and a hole injection layer 116. , a hole transport layer 117 , an electron transport layer 118 , and an electron injection layer 119 .

[0305] The electrode 101 includes a conductive layer 101a and a conductive layer 101b that is in contact with the conductive layer 101a. The electrode 103 includes a conductive layer 103a and a conductive layer 103b on and in contact with the conductive layer 103a. The electrode 104 has a conductive layer 104a and a conductive layer 103b on the conductive layer 104a. and an insulating layer 104b.

[0306] The light emitting element 262a shown in FIG. 10(A) and the light emitting element 262b shown in FIG. 10(B) are Region 222B sandwiched between electrode 101 and electrode 102, and region 222B sandwiched between electrode 102 and electrode 103 and a region 222R sandwiched between the electrode 102 and the electrode 104. The partition wall 145 has insulating properties. The partition wall 145 covers the ends of the electrodes 103 and 104 and has openings that overlap with the electrodes. By providing the electrodes, the electrodes on the substrate 200 in each region can be separated into islands. It becomes possible.

[0307] The charge generation layer 115 is formed by adding an electron acceptor to a hole transporting material. or an electron transporting material to which an electron donor (donor) is added, In addition, when the conductivity of the charge generating layer 115 is as high as that of the pair of electrodes, In this case, carriers generated by the charge generating layer 115 flow to the adjacent pixels, Therefore, it is necessary to prevent adjacent pixels from emitting light incorrectly. To achieve this, the charge generation layer 115 is formed of a material having a lower conductivity than the pair of electrodes. preferable.

[0308] The light emitting element 262a and the light emitting element 262b are arranged in the regions 222B, 222G, and The optical element 224B and the optical element 224C are arranged in the direction in which the light emitted from the region 222R is extracted. The substrate 220 has the optical element 224G and the optical element 224R. The light emitted from the region 222B is emitted to the outside of the light emitting element through each optical element. The light coming from the region 222G is emitted through the optical element 224B. The light emitted through 224G and emitted from the region 222R is reflected by the optical element 224R. It is ejected.

[0309] Furthermore, the optical elements 224B, 224G, and 224R are configured to For example, the optical element 224B has a function of selectively transmitting light of a specific color. The light emitted from the region 222B through the optical element 22 is blue light. The light emitted from the area 222G via the optical element 4G is green light. The light emitted from the region 222R via the element 224R is red light.

[0310] The optical elements 224R, 224G, and 224B may include, for example, a colored layer ( Color filters, bandpass filters, multilayer filters, etc. can be used. In addition, a color conversion element can be applied to the optical element. The color conversion element is an optical element that converts light into light with a longer wavelength than the wavelength of the light. By using quantum dots, the color reproducibility of the display device can be improved. can be increased.

[0311] It should be noted that if other optical elements are arranged on the optical elements 224R, 224G, and 224B, Other optical elements may be provided, for example, a circular polarizing plate or an anti-reflection plate. The circular polarizer is placed in a position where the light emitted by the light emitting element of the display device is extracted. When the light source is provided on the side where the light source is located, the light incident from outside the display device is reflected inside the display device and Furthermore, by providing an anti-reflection film, the surface of the display device can be prevented from being irradiated. This reduces the amount of external light reflected by the display device, making it possible to clearly see the light emitted by the display device. It can be observed.

[0312] In addition, in FIGS. 10(A) and 10(B), the light emitted from each region via each optical element is Light that exhibits blue (B), light that exhibits green (G), and light that exhibits red (R), respectively. This is shown schematically by dashed arrows.

[0313] In addition, a light-shielding layer 223 is provided between each optical element. The light-shielding layer 223 is formed to prevent light from entering from adjacent regions. It should be noted that the light-shielding layer 223 may not be provided. stomach.

[0314] The light-shielding layer 223 has a function of suppressing reflection of external light. The light-shielding layer 223 has a function of preventing the color mixture of light emitted from adjacent light-emitting elements. Examples include metals, resins containing black pigments, carbon black, metal oxides, and multiple metal oxides. A composite oxide containing a solid solution of such a material can be used.

[0315] The optical elements 224B and 224G are arranged in a region overlapping with the light-shielding layer 223. Alternatively, the optical element 224G and the optical element 224G may have an overlapping area. 24R may have an overlapping area with the light-shielding layer 223. Alternatively, the optical element 224R and the optical element 224B are arranged in an area where they overlap with the light-shielding layer 223. In this case, they may have overlapping regions.

[0316] The substrate 200 and the substrate 220 having the optical element are configured as in the first embodiment. Please take this into consideration.

[0317] Furthermore, the light emitting element 262a and the light emitting element 262b have a microcavity structure. .

[0318] <Microcavity structure> The light emitted from the light-emitting layer 170 and the light-emitting layer 190 is incident on a pair of electrodes (for example, electrode 10 The light emitting layer 170 and the light emitting layer 190 are resonated between the electrode 101 and the electrode 102. For example, the reflection area of ​​the electrode 101 is formed at a position where light of a desired wavelength is intensified. the optical distance from the reflecting area of ​​the electrode 102 to the light emitting area of ​​the light emitting layer 170; By adjusting the optical distance to the light emitting region, the amount of light emitted from the light emitting layer 170 can be reduced. In addition, the light emitted from the reflective region of the electrode 101 to the light emitting layer 190 can be intensified. and the optical distance from the reflective area of ​​the electrode 102 to the light-emitting area of ​​the light-emitting layer 190. By adjusting the optical distance, it is possible to obtain light of a desired wavelength from the light emitting layer 190. That is, the light can be intensified by using a plurality of light-emitting layers (here, the light-emitting layer 170 and the light-emitting layer In the case of a light emitting device in which the light emitting layer 170 and the light emitting layer 190 are stacked, the optical distances of the light emitting layer 170 and the light emitting layer 190 are It is preferable to optimize the separation.

[0319] In the light emitting element 262a and the light emitting element 262b, the conductive layer (conductive layer 1) is formed in each region. By adjusting the thickness of the conductive layer 101b, the conductive layer 103b, and the conductive layer 104b, the light-emitting layer 170 In addition, it is possible to enhance light of a desired wavelength among the light emitted from the light emitting layer 190. In the region, at least one of the hole injection layer 111 or the hole transport layer 112, or the electron injection By varying the thickness of at least one of the electron injection layer 119 and the electron transport layer 118, The light emitted from light-emitting layer 170 and light-emitting layer 190 may be intensified.

[0320] For example, the electrodes 101 to 104 are made of a conductive material having a function of reflecting light. When the refractive index is smaller than that of the light-emitting layer 170 or the light-emitting layer 190, the electrode The thickness of the conductive layer 101b of the electrode 101 is set so that the optical distance between the electrode 101 and the electrode 102 is m B λ B / 2(m B is a natural number, λ B represent the wavelengths of light to be intensified in region 222B, respectively) and Similarly, the thickness of the conductive layer 103b of the electrode 103 is adjusted to be equal to the thickness of the conductive layer 103b of the electrode 103. The optical distance between the electrode 102 is m G λ G / 2(m G is a natural number, λ G is strong in the area 222G The wavelength of the light emitted from the electrode 104 is adjusted to be 100 nm. The thickness of the electrode 104b is set such that the optical distance between the electrode 104 and the electrode 102 is m R λ R / 2(m R is self natural number, λ R and represent the wavelengths of the light to be intensified in the region 222R).

[0321] In addition, when it is difficult to precisely determine the reflective areas of the electrodes 101 to 104, By assuming that any region of the light-emitting layer 170 or the light-emitting electrode 101 to the electrode 104 is a reflective region, An optical path that enhances the light emitted from the light emitting layer 190 may be derived. When it is difficult to precisely determine the light-emitting region of the light-emitting layer 170 and the light-emitting layer 190, By assuming that any region of the light emitting layer 190 is a light emitting region, the light emitting layer 170 and the light emitting layer 190 An optical path that enhances the light emitted from the

[0322] As described above, a microcavity structure is provided, and the optical distance between a pair of electrodes in each region is adjusted. By adjusting the thickness, light scattering and absorption near each electrode are suppressed, resulting in high light extraction efficiency. The rate can be realized.

[0323] In the above structure, the conductive layer 101b, the conductive layer 103b, and the conductive layer 104b are optically It is preferable that the conductive layer 101b, the conductive layer 103b, and the conductive The materials constituting the layers 104a and 104b may be the same or different. When the same material is used for the conductive layer 101b, the conductive layer 103b, and the conductive layer 104b, 1. Pattern formation by etching process in the process of forming the electrodes 103 and 104 is easy. In addition, the conductive layers 101b, 103b, and 104b are preferably Each of these may have a structure in which two or more layers are laminated.

[0324] The light emitting element 262a shown in FIG. 10(A) is a top emission type light emitting element, and therefore, The layer 101a, the conductive layer 103a, and the conductive layer 104a may have a function of reflecting light. It is also preferable that the electrode 102 has a function of transmitting light and a function of reflecting light. is preferred.

[0325] Furthermore, the light emitting element 262b shown in FIG. 10(B) is a bottom emission type light emitting element. The conductive layer 101a, the conductive layer 103a, and the conductive layer 104a have a function of transmitting light and a function of reflecting light. It is preferable that the electrode 102 has a function of reflecting light. is preferred.

[0326] In the light-emitting element 262a and the light-emitting element 262b, the conductive layer 101a and the conductive layer 10 The same material may be used for the conductive layer 3a or the conductive layer 104a, or different materials may be used. When the same material is used for the conductive layer 101a, the conductive layer 103a, and the conductive layer 104a, the light emitting element The manufacturing costs of the conductive layer 101a and the light emitting element 262a and the light emitting element 262b can be reduced. The conductive layer 103a and the conductive layer 104a may each have a structure in which two or more layers are stacked. stomach.

[0327] In addition, the light-emitting layer 170 or the light-emitting layer 19 in the light-emitting element 262a and the light-emitting element 262b At least one of the configurations shown in the first and second embodiments is included in the first embodiment. By doing so, it is possible to obtain a light-emitting element having high luminous efficiency and high reliability. Therefore, a light-emitting element exhibiting such a property can be manufactured.

[0328] The light-emitting layer 170 and the light-emitting layer 190 are, for example, the light-emitting layer 190a and the light-emitting layer 190b. In this way, two layers may be laminated on one or both sides. The first compound and the second compound are two types of luminescent materials that have the function of exhibiting different colors. By using each of them, multiple lights can be emitted simultaneously. The luminescent material used in each luminescent layer is selected so that the luminescence exhibited by 190 becomes white. This is preferable.

[0329] In addition, the light-emitting layer 170 or the light-emitting layer 190 may have a structure in which three or more layers are laminated on one side or both sides. The light-emitting layer may be made of any material, or may include a layer that does not contain a light-emitting material.

[0330] As described above, the present invention can be realized by using at least one of the structures of the light-emitting layer shown in Embodiments 1 and 2. By using the light-emitting element 262a or the light-emitting element 262b having the same in a pixel of a display device, A display device with high light efficiency and high reliability can be manufactured. A display device having the light element 262a or the light emitting element 262b can reduce power consumption. can.

[0331] Other configurations of the light emitting element 262a and the light emitting element 262b are as follows: 260a or 260b, or the light-emitting element shown in the first and second embodiments. The configuration of the optical element should be taken into consideration.

[0332] <Method for manufacturing light-emitting elements> Next, a manufacturing method of a light-emitting element of one embodiment of the present invention will be described below with reference to FIGS. 11 and 12. Here, a method for manufacturing the light-emitting element 262a shown in FIG. explain.

[0333] 11 and 12 are cross-sectional views illustrating a method for manufacturing a light-emitting element of one embodiment of the present invention. be.

[0334] The method for fabricating the light emitting element 262a described below includes seven steps, namely, first to seventh steps. do.

[0335] <First Step> The first step is to form an electrode (specifically, a conductive layer 101 constituting the electrode 101) of the light-emitting element. a, conductive layer 103a constituting electrode 103, and conductive layer 104a constituting electrode 104) is a step of forming the above on a substrate 200 (see FIG. 11(A)).

[0336] In this embodiment, a conductive layer having a function of reflecting light is formed on a substrate 200. The conductive layer is processed into a desired shape, whereby the conductive layer 101a, the conductive layer 103a, and the conductive layer 104a are formed. The conductive layer 104a is formed by using silver and palladium. The film is made of an alloy of Ag and copper (also called Ag-Pd-Cu film or APC). The conductive layer 101a, the conductive layer 103a, and the conductive layer 104a are formed by a process of processing the same conductive layer. Forming the wiring board through this process is preferable because it reduces the manufacturing cost.

[0337] It should be noted that a plurality of transistors may be formed on the substrate 200 before the first step. In addition, the plurality of transistors, the conductive layer 101a, the conductive layer 103a, and the conductive layer 104a may be electrically connected to each other.

[0338] <<Second Step>> In the second step, a light-transmitting layer is formed on the conductive layer 101a constituting the electrode 101. The conductive layer 101b is formed on the conductive layer 103a constituting the electrode 103. The conductive layer 103b is formed on the conductive layer 104a of the electrode 104. This is a step of forming a conductive layer 104b (see FIG. 11(B)).

[0339] In this embodiment, the conductive layers 101a and 103a, which have a function of reflecting light, 104a, and 101b, respectively, are provided on the conductive layers 101b, 103b, and 104a, respectively, which have a light transmitting function. By forming the electrode 104b, the electrode 101, the electrode 103, and the electrode 104 are formed. The conductive layers 101b, 103b, and 104b are made of ITSO films.

[0340] The conductive layers 101b, 103b, and 104b having a function of transmitting light are formed multiple times. By forming the microcapsules in multiple steps, it is possible to form the microcapsules in each area. The conductive layers 101b, 103b, and 104b can be formed to a thickness that provides a cavity structure. Cut.

[0341] <Third Step> The third step is to form the partition walls 145 that cover the edges of the electrodes of the light-emitting element ( See Figure 11(C)).

[0342] The partition wall 145 has an opening so as to overlap with the electrode. In this embodiment, the partition wall 145 is made of a polyimide resin. Use fat.

[0343] In the first to third steps, the EL layer (layer containing an organic compound) is not damaged. Since there is no risk of this, various film forming methods and microfabrication techniques can be applied. The method uses a sputtering method to form a reflective conductive layer, and then uses a lithography method to form a reflective conductive layer. A pattern is formed on the conductive layer, and then the pattern is formed by dry etching or wet etching. The conductive layer is processed into an island shape, whereby the conductive layer 101a constituting the electrode 101 and the electrode 10 A conductive layer 103a constituting the electrode 3 and a conductive layer 104a constituting the electrode 104 are formed. Thereafter, a transparent conductive film is formed by sputtering, and then a lithography method is used. Then, a pattern is formed on the transparent conductive film, and then the pattern is removed by wet etching. The transparent conductive film is then processed into islands to form electrodes 101, 103, and 104. do.

[0344] <Fourth Step> The fourth step is to form a hole injection layer 111, a hole transport layer 112, an emissive layer 190, an electron transport layer This is a step of forming a layer 113, an electron injection layer 114, and a charge generation layer 115 (FIG. 12(A) reference).

[0345] The hole injection layer 111 is formed by co-evaporating a hole transporting material and a material containing an acceptor material. Co-evaporation is the process of depositing different materials on different surfaces. The hole transport layer 112 is a vapor deposition method in which the hole It can be formed by vapor deposition of a transport material.

[0346] The light-emitting layer 190 may be purple, blue, blue-green, green, yellow-green, yellow, orange, or red. The light-emitting layer is formed by depositing at least one luminescent guest material selected from the following: As the guest material, a light-emitting organic compound that exhibits fluorescence or phosphorescence is used. In addition, the light-emitting layer having the structure shown in Embodiments 1 and 2 can be used. The light-emitting layer 190 may also be configured as two layers. The optical layers preferably contain luminescent organic compounds that emit light of different colors. stomach.

[0347] The electron transporting layer 113 can be formed by evaporating a substance with a high electron transporting property. The electron injection layer 114 can be formed by evaporating a material with high electron injection properties. It is possible.

[0348] The charge generation layer 115 is made of a material in which an electron acceptor is added to a hole transporting material. or a material in which an electron donor (donor) is added to an electron transporting material. It can be formed by

[0349] <5th step> The fifth step is to deposit the hole injection layer 116, the hole transport layer 117, the light emitting layer 170, and the electron transport layer 118. 118, an electron injection layer 119, and an electrode 102 are formed (see FIG. 12(B)). .

[0350] The hole injection layer 116 is formed using the same material and method as the hole injection layer 111 described above. The hole transport layer 117 can be formed by the above-described hole transport layer 11. It can be formed using the same materials and methods as in 2.

[0351] The light-emitting layer 170 may be purple, blue, blue-green, green, yellow-green, yellow, orange, or red. The resulting film is formed by depositing at least one luminescent guest material selected from the following: The guest material can be a light-emitting organic compound that exhibits fluorescence or phosphorescence. In addition, the light-emitting layer having the structure shown in Embodiment 1 and Embodiment 2 can be used. It is preferable that the light-emitting layer 170 and the light-emitting layer 190 emit light differently from each other. It is preferable to use a light-emitting organic compound having the function of

[0352] The electron transport layer 118 is formed using the same material and method as the electron transport layer 113 described above. The electron injection layer 119 can be formed by the above-described electron injection layer 11. It can be formed using the same materials and methods as in 4.

[0353] The electrode 102 is formed by stacking a reflective conductive film and a light-transmitting conductive film. The electrode 102 can be formed as a single layer structure or a stacked layer structure. Good too.

[0354] Through the above steps, regions 222 are formed on the electrodes 101, 103, and 104, respectively. A light-emitting device having regions 222B, 222G, and 222R is formed on substrate 200.

[0355] <Sixth Step> In the sixth step, the light-shielding layer 223, the optical element 224B, and the optical element 224 are formed on the substrate 220. This is a step of forming the optical element 224G and the optical element 224R (see FIG. 12(C)).

[0356] The light-shielding layer 223 is formed by forming a resin film containing a black pigment in a desired area. On the plate 220 and the light-shielding layer 223, an optical element 224B, an optical element 224G, and an optical element 224G are provided. As the optical element 224B, a resin film containing a blue pigment is applied to a desired area. In addition, as the optical element 224G, a resin film containing a green pigment is formed in a desired area. In addition, the optical element 224R is formed by forming a resin film containing a red pigment in a desired area. do.

[0357] <Seventh Step> The seventh step is to separate the light emitting element formed on the substrate 200 and the light emitting element formed on the substrate 220. The light-shielding layer 223, the optical element 224B, the optical element 224G, and the optical element 224R are bonded together. This is a process of joining the components together and sealing them with a sealant (not shown).

[0358] Through the above steps, the light-emitting element 262a shown in FIG. 10(A) can be formed.

[0359] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there.

[0360] (Fourth embodiment) In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS. Reveal.

[0361] <Display device configuration example 1> 13A is a top view showing the display device 600, and FIG. 13B is a diagram showing the display device 600 along the dashed line in FIG. 13A. The display device 600 is a cross-sectional view taken along the line AB and the dashed line CD. It has a signal line driver circuit portion 601, a scanning line driver circuit portion 603, and a pixel portion 602. The signal line driver circuit portion 601, the scanning line driver circuit portion 603, and the pixel portion 602 are It has the function of controlling the light emission of the element.

[0362] The display device 600 also includes an element substrate 610, a sealing substrate 604, a sealant 605, The device has an area 607 surrounded by a sealing material 605, wiring 608, and an FPC 609. do.

[0363] The lead wiring 608 is connected to the signal line driver circuit portion 601 and the scanning line driver circuit portion 603. This is the wiring for transmitting the input signal, and is connected to the external input terminal FPC609. It receives the FP signal, clock signal, start signal, reset signal, etc. Although only C609 is shown, FPC609 has a printed wiring board (PWB). A wired wiring board may be installed.

[0364] The signal line driver circuit portion 601 includes an N-channel transistor 623 and a P-channel transistor A CMOS circuit is formed by combining this transistor 624. The path section 601 or the scanning line driving circuit section 603 may be implemented by various CMOS circuits, PMOS circuits, or In this embodiment, a NMOS circuit can be used. Although the display device shown has the driver and pixels on the same surface of the substrate, this is not necessarily the case. In addition, the drive circuit section can be formed externally rather than on the substrate.

[0365] The pixel portion 602 includes a switching transistor 611 and a current control transistor. a lower part electrically connected to the drain of the current control transistor 612; A partition wall 614 is formed to cover the edge of the lower electrode 613. The partition wall 614 can be made of a positive photosensitive acrylic resin film.

[0366] In order to improve the covering property, the partition wall 614 is provided with a curved surface having a curvature at the upper end or the lower end. For example, the partition wall 614 is made of a positive photosensitive acrylic. In this case, only the upper end of the partition wall 614 is curved to have a radius of curvature (0.2 μm or more and 3 μm or less). It is preferable that the partition wall 614 is made of a negative photosensitive resin or a polyimide. Any of the photosensitive resins of the di-type can be used.

[0367] The structure of the transistors (transistors 611, 612, 623, and 624) is For example, a staggered transistor may be used. There is no particular limitation on the polarity, and it has N-channel and P-channel transistors. and either an N-channel transistor or a P-channel transistor. A structure consisting of only one of the two may also be used. For example, an amorphous semiconductor film or a crystalline semiconductor film can be used. Semiconductor materials include group 14 (silicon, etc.) semiconductors, compound semiconductors (oxide As the transistor, for example, An energy gap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more By using the oxide semiconductor, the off-state current of the transistor can be reduced. As the oxide semiconductor, In-Ga oxide, In-M-Zn oxide (M is , aluminum (Al), gallium (Ga), yttrium (Y), zirconium (Zr ), lanthanum (La), cerium (Ce), tin (Sn), hafnium (Hf), or nickel Examples include neodymium (Nd).

[0368] An EL layer 616 and an upper electrode 617 are formed on the lower electrode 613. The lower electrode 613 functions as an anode, and the upper electrode 617 functions as a cathode. do.

[0369] The EL layer 616 can be formed by a deposition method (including a vacuum deposition method) using a deposition mask, a droplet discharge method, or the like. (also called inkjet method), coating methods such as spin coating, gravure printing, etc. The EL layer 616 is formed by the method. The material for forming the EL layer 616 is a low molecular weight compound, Alternatively, it may be a polymer compound (including an oligomer or a dendrimer).

[0370] The lower electrode 613, the EL layer 616, and the upper electrode 617 form a light-emitting element 618. The light emitting element 618 has the structure of any one of the first to third embodiments. In addition, when a plurality of light-emitting elements are formed in a pixel portion, the same as those in Embodiments 1 to 4 are preferably used. The light-emitting element according to the third embodiment and the light-emitting element having other structures are both included. That's fine.

[0371] In addition, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, The light-emitting element is disposed in an area 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The region 607 is filled with a filler. In addition to being filled with an inert gas (nitrogen, argon, etc.), it can also be used as a sealing material 605. They may also be filled with UV or heat curable resins that can be used for various applications, such as PVC ( Polyvinyl chloride) resin, acrylic resin, polyimide resin, epoxy resin, Silicone resin, PVB (Polyvinyl Butyral) resin, or EVA (Ethylene Vinyl A recess is formed in the sealing substrate, and a desiccant is placed in the recess. By providing this, deterioration due to the influence of moisture can be suppressed, which is a preferable configuration.

[0372] In addition, the optical element 621 is disposed below the sealing substrate 604 so as to overlap the light emitting element 618. In addition, a light-shielding layer 622 is provided below the sealing substrate 604. The optical element and the light-shielding layer 621 and the light-shielding layer 622 are respectively the optical element and the light-shielding layer shown in the third embodiment. The same configuration may be used.

[0373] It is preferable to use epoxy resin or glass frit for the sealing material 605. In addition, it is desirable that these materials be as impermeable to moisture and oxygen as possible. In addition, the material used for the sealing substrate 604 may be a glass substrate, a quartz substrate, or an FRP (Fiber Reinforced Plastic) substrate. Reinforced Plastics), PVF (Polyvinyl Fluoride), Poly A plastic substrate made of ester, acrylic or the like can be used.

[0374] Here, a method for forming the EL layer 616 by droplet discharge will be explained with reference to FIG. 22A to 22D are cross-sectional views illustrating a method for manufacturing the EL layer 616. be.

[0375] First, in FIG. 22(A), a device substrate on which a lower electrode 613 and a partition wall 614 are formed is shown. 610 is shown, but as shown in FIG. 13, a lower electrode 613 and a partition wall 614 are formed on the insulating film. A substrate formed on the substrate may also be used.

[0376] Next, droplets are discharged from a droplet discharge device 683 to the exposed portion of the lower electrode 613, which is the opening of the partition wall 614. Droplets 684 are ejected to form a layer 685 containing the composition. The substance is attached onto the lower electrode 613 (see FIG. 22(B)).

[0377] The step of discharging the droplets 684 may be carried out under reduced pressure.

[0378] Next, the solvent is removed from the layer 685 containing the composition, and the layer is solidified to form the EL layer 616. (See FIG. 22(C)).

[0379] The solvent may be removed by a drying step or a heating step.

[0380] Next, an upper electrode 617 is formed on the EL layer 616 to form a light-emitting element 618 (FIG. 22 (See (D)).

[0381] In this way, when the EL layer 616 is formed by a droplet discharge method, the composition can be selectively discharged. This allows for a reduction in material waste. Since no filming process is required, the process can be simplified and costs can be reduced.

[0382] The droplet discharge method described above is a method of discharging a composition using a nozzle having a discharge port, or It is a general term for anything that has a means for ejecting droplets, such as a head with multiple nozzles.

[0383] Next, a droplet discharge device used in the droplet discharge method will be described with reference to FIG. 14 is a conceptual diagram illustrating a droplet ejection device 1400. FIG.

[0384] The droplet discharge device 1400 has a droplet discharge means 1403. 3 has a head 1405 and a head 1412.

[0385] The head 1405 and the head 1412 are connected to a control means 1407, which controls the computer. By controlling the image forming apparatus 1410, it is possible to draw a pattern in a pre-programmed manner. can.

[0386] The timing of drawing may be, for example, the timing of the marker 1 formed on the substrate 1402. Alternatively, the reference point may be determined based on the outer edge of the substrate 1402. Here, the marker 1411 is detected by the imaging means 1404, and the image processing means 1 The signal converted into a digital signal by 409 is recognized by a computer 1410 and a control signal is generated. The generated signal is sent to the control means 1407.

[0387] The imaging means 1404 may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CM An image sensor using an OS can be used. The information on the pattern to be created is stored in the storage medium 1408. A control signal is sent to the control means 1407, and the individual heads 1405, The material to be dispensed is supplied from a material supply source 1413, a material supply source 1414, a material supply source 1415, a material supply source 1416, a material supply source 1417, a material supply source 1418, a material supply source 1419, a material supply source 1420, a material supply source 1421, a material supply source 1422, a material supply source 1423, a material supply source 142 The fuel is supplied from a fuel supply source 1414 through piping to heads 1405 and 1412, respectively. do.

[0388] The inside of the head 1405 is a space 1406 filled with a liquid material, as shown by the dotted line, and a discharge space 1408. Although not shown, head 1412 is also a head 1. The head 1405 and the head 1412 have the same internal structure. By providing the pattern with a different size, different materials can be simultaneously written in patterns with different widths. A single head can eject multiple types of luminescent materials and draw patterns. In addition, when drawing a pattern over a wide area, multiple The same material can be ejected from multiple nozzles at the same time to create a pattern. The rod 1405 and the head 1412 move automatically on the substrate in the directions of the X, Y, and Z arrows shown in FIG. The area to be drawn can be freely set by scanning the substrate at will, and the same pattern can be printed multiple times on a single substrate. A number can be drawn.

[0389] The step of discharging the composition may be carried out under reduced pressure. After the composition is discharged, one or both of the steps of drying and baking are carried out. Both processes involve heat treatment, but the purpose, temperature and time are different. The firing process is carried out under normal or reduced pressure by laser light irradiation, instantaneous thermal annealing, or a heating furnace. The timing of the heat treatment and the number of times the heat treatment is performed are not particularly limited. In order to perform the drying and baking processes well, the temperature at which they are performed depends on the material of the substrate and the properties of the composition. Depends on.

[0390] As described above, the EL layer 616 can be manufactured using a droplet discharge apparatus.

[0391] As described above, the light emitting element and the optical element described in any of the first to third embodiments are used. A display device can be obtained.

[0392] <Display device configuration example 2> Next, another example of the display device will be described with reference to FIGS. 14(A), 14(B) and 15. 14A, 14B, and 15 are cross-sectional views of display devices according to embodiments of the present invention. .

[0393] FIG. 14(A) shows a substrate 1001, an underlying insulating film 1002, a gate insulating film 1003, a gate Electrodes 1006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 10 21, peripheral portion 1042, pixel portion 1040, driving circuit portion 1041, lower electrode 10 of light-emitting element 24R, 1024G, 1024B, partition wall 1025, EL layer 1028, upper electrode of light-emitting element 1026, a sealing layer 1029, a sealing substrate 1031, a sealing material 1032, etc. are shown. .

[0394] In addition, in FIG. 14(A), as an example of an optical element, a colored layer (a red colored layer 1034R, A green colored layer 1034G and a blue colored layer 1034B are provided on a transparent substrate 1033. A light-shielding layer 1035 may be further provided. The base material 1033 is aligned and fixed to the substrate 1001. is covered with an overcoat layer 1036. In FIG. 14(A), the colored layer Since the light that passes through the screen is red, green, and blue, images can be displayed using three color pixels.

[0395] In FIG. 14B, as an example of an optical element, a colored layer (a red colored layer 1034R, a green colored layer The colored layer 1034G and the blue colored layer 1034B are formed between the gate insulating film 1003 and the first interlayer insulating film. In this example, the colored layer is formed between the substrate 1001 and the film 1020. It may be provided between the substrates 1031 .

[0396] In FIG. 15, as an example of an optical element, a colored layer (a red colored layer 1034R, a green colored layer 1034G, blue colored layer 1034B) between the first interlayer insulating film 1020 and the second interlayer insulating film In this example, the colored layer is formed between the substrate 1001 and the sealing substrate 1021. It may be provided between the plates 1031.

[0397] In the display device described above, the substrate 1001 side on which the transistors are formed is The display device has a structure for extracting light (bottom emission type), but The display device may also have a structure in which light is extracted (top emission type).

[0398] <Configuration example 3 of the display device> An example of a cross-sectional view of a top-emission type display device is shown in Figures 16(A) and 16(B). 14(A) and 14(B) are cross-sectional views illustrating a display device of one embodiment of the present invention. 15.) and the driving circuit section 1041, the peripheral section 1042, etc. shown in FIG. 15 are omitted in the illustration.

[0399] In this case, the substrate 1001 can be a substrate that does not transmit light. Until the connection electrode that connects to the anode of the optical element is fabricated, it is a bottom emission type display device. Then, a third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film may also have a role of planarization. In addition to the same material as the interlayer insulating film 2, various other materials can be used.

[0400] The lower electrodes 1024R, 1024G, and 1024B of the light-emitting element are anodes here, but Also, top emission type displays as shown in Figure 16(A)(B) can be used. In the case of a device, the lower electrodes 1024R, 1024G, and 1024B have a function of reflecting light. In addition, an upper electrode 1026 is provided on the EL layer 1028. The electrode 1026 has a function of reflecting light and a function of transmitting light. A microcavity structure is adopted between 24G, 1024B and the upper electrode 1026, It is desirable to increase the light intensity at a particular wavelength.

[0401] In the top emission structure shown in FIG. 16(A), the colored layer (red colored layer 1034 A sealing substrate 1031 provided with a green colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B The sealing substrate 1031 has a shielding layer positioned between the pixels. An optical layer 1035 may be provided. Note that the sealing substrate 1031 may be a light-transmitting substrate. It is suitable.

[0402] In addition, in FIG. 16(A), a plurality of light emitting elements and colored light emitting elements are provided. Although the configuration in which a layer is provided is shown as an example, the present invention is not limited to this. For example, as shown in FIG. In this case, the green color layer is not provided, and only the red color layer 1034R and the blue color layer 1034B are provided. It is also possible to use a configuration in which a full color display is performed using three colors, red, green, and blue. In this way, when a light emitting element and a colored layer are provided for each of the light emitting elements, reflection of external light can be reduced. On the other hand, as shown in FIG. 16(B), In the case where a red colored layer and a blue colored layer are provided without providing a colored layer of green, Since there is little energy loss in the light emitted from the light-emitting element, power consumption can be reduced. This has a positive effect.

[0403] <Display device configuration example 4> The display device described above has a configuration having sub-pixels of three colors (red, green, and blue). A structure with four color sub-pixels (red, green, blue, yellow, or red, green, blue, white) 17 to 19 show the lower electrodes 1024R, 1024G, 1024B, 17(A), (B) and 18 show the configuration of a display device having 1024Y. A structure in which light is extracted from the substrate 1001 side where the transistor is formed (bottom emission type) 19(A) and 19(B) show a structure in which light is extracted to the sealing substrate 1031 side ( It is a top-emission display device.

[0404] FIG. 17(A) shows the optical element (colored layer 1034R, colored layer 1034G, colored layer 1034B 17 is an example of a display device in which a colored layer 1034Y is provided on a transparent substrate 1033. (B) shows the optical elements (colored layer 1034R, colored layer 1034G, colored layer 1034B) in a gate. This is an example of a display device formed between the first insulating film 1003 and the first interlayer insulating film 1020. FIG. 18 shows the optical element (colored layer 1034R, colored layer 1034G, colored layer 1034B, A color layer 1034Y is formed between the first interlayer insulating film 1020 and the second interlayer insulating film 1021. This is an example of a display device.

[0405] The colored layer 1034R transmits red light, the colored layer 1034G transmits green light, and the colored layer The colored layer 1034B has a function of transmitting blue light, and the colored layer 1034Y has a function of transmitting yellow light. The ability to transmit multiple colors of light selected from blue, green, yellow, and red. The colored layer 1034Y transmits a plurality of light beams selected from blue, green, yellow, and red. When the color layer 1034Y has a function of transmitting light, the light transmitted through the color layer 1034Y may be white. Since the light emitting element that emits white light has high luminous efficiency, it is preferable to use the light emitting element that emits white light in the display having the colored layer 1034Y. The device can reduce power consumption.

[0406] In the top emission type display device shown in FIG. 19, the lower electrode 1024Y In the light-emitting element having the same structure, the upper electrode 1026 is connected to the light-emitting element 1026 in the same manner as in the display device of FIG. Among them, a structure having a microcavity structure is preferable. Now, the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 103 The sealing can be performed by a sealing substrate 1031 provided with a yellow colored layer 1034Y. do.

[0407] The light emitted through the microcavity and the yellow colored layer 1034Y is in the yellow region. Yellow is a color with high visibility, so yellow light is emitted. That is, the display device having the structure shown in FIG. , power consumption can be reduced.

[0408] In addition, in FIG. 19(A), a plurality of light emitting elements and colored light emitting elements are provided. Although the configuration in which a layer is provided is shown as an example, the present invention is not limited to this. For example, as shown in FIG. , the yellow colored layer is not provided, and the red colored layer 1034R, the green colored layer 1034G, and the blue colored layer 1034R are provided. A colored layer 1034B is provided to allow the four colors of red, green, blue, and yellow, or red, green, blue, and white. As shown in FIG. 19(A), a light-emitting element and the light-emitting element When a colored layer is provided on each optical element, it is possible to suppress the reflection of external light. On the other hand, as shown in FIG. 19(B), a light emitting element is provided with no yellow coloring layer, and a red coloring layer is provided. When a colored layer of a color, a green colored layer, and a blue colored layer are provided, yellow or white Since there is little energy loss in the light emitted from the light-emitting element, power consumption can be reduced. This has a positive effect.

[0409] <Display Device Configuration Example 5> Next, a display device according to another embodiment of the present invention is shown in FIG. 20. FIG. 20 shows the same display device as FIG. 13(A) 20 is a cross-sectional view taken along dashed lines AB and CD. In this regard, parts having the same functions as those shown in FIG. 13(B) are denoted by the same reference numerals, and their details are shown in the same manner as those shown in FIG. Detailed explanations will be omitted.

[0410] The display device 600 shown in FIG. 20 includes an element substrate 610, a sealing substrate 604, and a sealing material 60 The region 607 surrounded by 5 has sealing layers 607a, 607b, and 607c. For example, one or more of the sealing layers 607a, 607b, and 607c may include For example, PVC (polyvinyl chloride) resin, acrylic resin, polyimide resin, epoxy resin, silicone resin, PVB (polyvinyl butyral) resin, or EVA Resins such as ethylene vinyl acetate resins can be used. silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, aluminum nitride Alternatively, an inorganic material such as aluminum may be used. By forming the layer c, it is possible to suppress deterioration of the light emitting element 618 due to impurities such as water. It is preferable to form the sealing layer 607a, the sealing layer 607b, and the sealing layer 607c. The cooling material 605 does not need to be provided.

[0411] In addition, the sealing layer 607a, the sealing layer 607b, and the sealing layer 607c may be any one or two. Alternatively, four or more sealing layers may be formed. Impurities such as these may penetrate from the outside of the display device 600 to the light emitting element 618 inside the display device. In addition, when the sealing layer is multi-layered, the sealing layer may be made of a resin and an inorganic material. It is preferable to laminate the material.

[0412] <Display Device Configuration Example 6> The display devices shown in Configuration Examples 1 to 4 in this embodiment include optical elements. However, in one embodiment of the present invention, an optical element does not necessarily have to be provided.

[0413] The display device shown in FIGS. 21(A) and 21(B) has a structure in which light is extracted to the sealing substrate 1031 side (transistor). FIG. 21(A) shows a display device of a light-emitting layer 1028R, a light-emitting layer 1028R, and a light-emitting layer 1028R. 21B is an example of a display device having a light-emitting layer 1028G and a light-emitting layer 1028B. A surface having an optical layer 1028R, an emissive layer 1028G, an emissive layer 1028B, and an emissive layer 1028Y. This is an example of a display device.

[0414] The light-emitting layer 1028R emits red light, the light-emitting layer 1028G emits green light, and The light-emitting layer 1028B has a function of emitting blue light. or a function of exhibiting multiple luminescence selected from blue, green, and red. The light emitted by the light-emitting layer 1028Y may be white. Since the light-emitting element that emits light has high luminous efficiency, the display device having the light-emitting layer 1028Y has high luminous efficiency. Power consumption can be reduced.

[0415] The display devices shown in FIGS. 21(A) and 21(B) each have an EL layer that emits light of different colors. Since the colored layer is provided in the pixel, it is not necessary to provide a colored layer that serves as an optical element.

[0416] The sealing layer 1029 is made of, for example, a PVC (polyvinyl chloride) resin or an acrylic resin. resin, polyimide resin, epoxy resin, silicone resin, PVB (polyvinyl bromide) Resins such as ethylene vinyl acetate (EVA) resins can be used. In addition, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride Alternatively, an inorganic material such as aluminum oxide or aluminum nitride may be used. By forming the insulating layer, deterioration of the light emitting element due to impurities such as water can be suppressed, which is preferable.

[0417] The sealing layer 1029 may be any one or two, or may be four or more sealing layers. By forming the sealing layer in multiple layers, impurities such as water can be prevented from entering the display device from the outside. This is preferable because it can effectively prevent the particles from penetrating into the inside of the display device. In the case of a multi-layer structure, a preferable structure is one in which a resin and an inorganic material are laminated.

[0418] The sealing substrate 1031 may have any function as long as it has a function of protecting the light-emitting element. Therefore, a flexible substrate or film can be used for the sealing substrate 1031.

[0419] Note that the configuration shown in this embodiment may be appropriately combined with other embodiments or other configurations in this embodiment. Combinations are possible.

[0420] (Embodiment 5) In this embodiment, a display device including a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. The explanation will be given with reference to FIG.

[0421] Note that FIG. 24A is a block diagram illustrating a display device of one embodiment of the present invention, and 4(B) is a circuit diagram illustrating a pixel circuit included in a display device of one embodiment of the present invention.

[0422] <Explanation about the display device> The display device shown in FIG. 24A has a region having pixels of a display element (hereinafter referred to as a pixel portion 802). ) and a circuit section ( hereinafter referred to as a drive circuit section 804), and a circuit having a function of protecting the element (hereinafter referred to as a protection circuit 80 6) and a terminal portion 807. Note that the protection circuit 806 is not provided in the configuration. That's fine.

[0423] A part or the whole of the driver circuit portion 804 is formed on the same substrate as the pixel portion 802. This makes it possible to reduce the number of parts and terminals. When a part or all of the driving circuit is not formed on the same substrate as the pixel portion 802, A part or the whole of the path portion 804 is COG or TAB (Tape Automated Bearing). It can be implemented by

[0424] The pixel section 802 is arranged in X rows (X is a natural number of 2 or more) and Y columns (Y is a natural number of 2 or more). The display device has a circuit for driving a plurality of display elements (hereinafter referred to as pixel circuit 801), The path portion 804 is a circuit for outputting a signal (scanning signal) for selecting a pixel (hereinafter referred to as a scanning line driving circuit 804a), for supplying signals (data signals) for driving the display elements of the pixels. The signal line driver circuit 804b includes a driver circuit such as the circuit (hereinafter referred to as a signal line driver circuit 804b).

[0425] The scanning line driver circuit 804a includes a shift register and the like. A signal for driving the shift register is inputted through the terminal portion 807, and a signal is outputted. For example, a start pulse signal, a clock signal, etc. are input to the scanning line driver circuit 804a. The scanning line driving circuit 804a is connected to the wiring to which the scanning signal is applied (hereinafter referred to as the wiring). The scanning lines GL_1 to GL_X are connected to the gate electrode GL_1. A plurality of driving circuits 804a are provided, and the scanning lines GL_1 to GL_3 are driven by the plurality of scanning line driving circuits 804a. Alternatively, the scanning line driving circuit 804a may control the GL_X by dividing it. However, the present invention is not limited to this, and the scanning line driving circuit 80 4a may also provide other signals.

[0426] The signal line driver circuit 804b includes a shift register and the like. Through the terminal portion 807, signals for driving the shift register as well as the source of the data signal are transmitted. The signal line driver circuit 804b receives the image signal and drives the pixel circuit The signal line driver circuit 804b has a function of generating a data signal to be written to the signal line driver circuit 804b. A data signal is generated in accordance with a pulse signal obtained by inputting a start pulse, a clock signal, etc. The signal line driver circuit 804b has a function of controlling the output of a signal. The data lines DL_1 to DL_Y are connected to the data lines DL_2 through DL_Y. Alternatively, the signal line driver circuit 804b may have a function of supplying an initialization signal. However, the present invention is not limited to this, and the signal line driver circuit 804b may also supply other signals. It is possible.

[0427] The signal line driver circuit 804b is configured using, for example, a plurality of analog switches. The signal line driver circuit 804b sequentially turns on a plurality of analog switches, The image signal can be time-divided and output as a data signal. The signal line driver circuit 804b may be configured using the same.

[0428] Each of the plurality of pixel circuits 801 is connected to one of the plurality of scanning lines GL to which a scanning signal is applied. A pulse signal is input via the data line DL, and a data signal is given via one of the data lines DL. Each of the pixel circuits 801 receives a data signal via a scanning line driving circuit. 804a controls the writing and holding of data of the data signal. The second pixel circuit 801 is connected to the scanning line driving circuit GL_m (m is a natural number equal to or less than X) via the scanning line GL_m. A pulse signal is input from 804a, and the potential of the data line DL_n ( A data signal is input from the signal line driver circuit 804b via the signal line driver circuit 804b (n is a natural number equal to or less than Y).

[0429] The protection circuit 806 shown in FIG. 24A is, for example, a protection circuit including a scanning line driving circuit 804a and a pixel circuit 804b. 01. Alternatively, the protection circuit 806 is connected to the scanning line GL, which is the wiring between the signal line driver The data line DL is connected between the circuit 804b and the pixel circuit 801. The protection circuit 806 can be connected to the wiring between the scanning line driving circuit 804a and the terminal portion 807. Alternatively, the protection circuit 806 may be formed on the wiring between the signal line driver circuit 804b and the terminal portion 807. The terminal portion 807 can be connected to a power supply and a line from an external circuit to the display device. This refers to the part where terminals for inputting control signals and image signals are provided.

[0430] When a potential outside a certain range is applied to the wiring to which the protection circuit 806 is connected, the protection circuit 806 This is a circuit that brings one wire into electrical continuity with another wire.

[0431] As shown in FIG. 24A, a pixel section 802 and a driver circuit section 804 are provided with a protection circuit 80. 6. By connecting the This can improve the display device's resistance to overcurrents caused by electrostatic discharge (ESD) and other factors. However, the configuration of the protection circuit 806 is not limited to this. For example, or a configuration in which the protection circuit 806 is connected to the signal line driver circuit 804b. Alternatively, a configuration in which a protection circuit 806 is connected to the terminal portion 807 may be used. It can also be made into a

[0432] In FIG. 24A, the scanning line driver circuit 804a and the signal line driver circuit 804b Therefore, although an example in which the driver circuit portion 804 is formed is shown, the present invention is not limited to this configuration. For example, only the scanning line driver circuit 804a is formed, and a signal line driver circuit prepared separately is formed. A substrate (for example, a drive circuit board formed of a single crystal semiconductor film or a polycrystalline semiconductor film) is mounted. It may also be configured as follows.

[0433] <Pixel circuit configuration example> The plurality of pixel circuits 801 shown in FIG. 24(A) may have the configuration shown in FIG. 24(B), for example. It is possible.

[0434] The pixel circuit 801 shown in FIG. 24B includes transistors 852 and 854 and a capacitor 86 2 and a light-emitting element 872.

[0435] One of the source electrode and the drain electrode of the transistor 852 is supplied with a data signal. The gate of the transistor 852 is electrically connected to the wiring (data line DL_n). The electrodes are electrically connected to wiring (scanning lines GL_m) to which gate signals are applied.

[0436] The transistor 852 has a function of controlling writing of data signals.

[0437] One of the pair of electrodes of the capacitor 862 is connected to a wiring to which a potential is applied (hereinafter, a potential supply line VL _a), and the other is electrically connected to the source electrode and drain electrode of the transistor 852. The second electrode is electrically connected to the other of the first and second electrodes.

[0438] The capacitor 862 functions as a storage capacitor for holding written data.

[0439] One of the source electrode and the drain electrode of the transistor 854 is connected to the potential supply line VL_a. Furthermore, the gate electrode of transistor 854 is electrically connected to the It is electrically connected to the other of the source electrode and the drain electrode.

[0440] One of the anode and cathode of the light emitting element 872 is electrically connected to the potential supply line VL_b. The other is electrically connected to the other of the source electrode and drain electrode of the transistor 854. will be done.

[0441] The light-emitting element 872 may be any of the light-emitting elements described in any of Embodiments 1 to 3. can be done.

[0442] A high power supply potential VDD is applied to one of the potential supply lines VL_a and VL_b. and the other is supplied with a low power supply potential VSS.

[0443] In a display device having the pixel circuit 801 of FIG. 24(B), for example, The scanning line driving circuit 804a sequentially selects the pixel circuits 801 in each row, and turns on the transistors 852. The data signal is written by turning it on.

[0444] The pixel circuit 801 in which data has been written is turned off by turning off the transistor 852. Furthermore, the potential of the transistor 854 changes depending on the potential of the written data signal. The amount of current flowing between the source electrode and the drain electrode is controlled, and the light emitting element 872 The light is emitted at a brightness that corresponds to the flow rate. By repeating this process row by row, an image can be displayed.

[0445] In addition, the pixel circuit has a function to correct the influence of fluctuations in the threshold voltage of the transistor, etc. 25(A)(B) and 26(A)(B) show examples of pixel circuits.

[0446] The pixel circuit shown in FIG. 25A includes six transistors (transistors 303_1 to 303_3). 303_6), a capacitor 304, and a light-emitting element 305. The pixel circuit shown in FIG. 1 includes wirings 301_1 to 301_5, a wiring 302_1, and a wiring 30 2_2 are electrically connected. For example, a P-channel transistor can be used.

[0447] The pixel circuit shown in FIG. 25B is the pixel circuit shown in FIG. 25A, except that a transistor 303 25(B) is configured to add a wiring 301_6 and a wiring 301_7. The wiring 301_5 and the wiring 301_6 are electrically connected. may be electrically connected to each other. For example, a P-channel transistor can be used.

[0448] The pixel circuit shown in FIG. 26A includes six transistors (transistors 308_1 to 308_3). 26(A) and 26(B) are provided. The pixel circuit shown in FIG. Here, the wiring 306_1 and the wiring 306_3 are electrically connected. The transistors 308_1 to 308_6 may be electrically connected. For example, a P-channel transistor can be used.

[0449] The pixel circuit shown in FIG. 26B includes two transistors (transistor 309_1 and transistor transistor 309_2) and two capacitance elements (capacitance element 304_1 and capacitance element 304_ 2) and a light-emitting element 305. In addition, the pixel circuit shown in FIG. The wirings 11_1 to 311_3, the wiring 312_1, and the wiring 312_2 are electrically connected to each other. In addition, by configuring the pixel circuit as shown in FIG. 26(B), for example, The transistor 309 can be a current-driven type (also called a CVCC type). For example, a P-channel transistor can be used for the transistors 1 and 309_2. .

[0450] Furthermore, the light-emitting element of one embodiment of the present invention may be an active matrix light-emitting element having an active element in a pixel of a display device. The display device is a passive matrix type that does not have active elements in the pixels. It can be applied to each method.

[0451] In the active matrix system, the active element (active element, nonlinear element) is a transistor. By using not only transistors but also various active elements (active elements, nonlinear elements), For example, MIM (Metal Insulator Metal) or T It is also possible to use FD (Thin Film Diode) and other elements. Since the number of manufacturing steps is small, it is possible to reduce manufacturing costs and improve yields. Alternatively, these elements can improve the aperture ratio due to their small size. This makes it possible to achieve low power consumption and high brightness.

[0452] Other than the active matrix type, active elements (active elements, nonlinear elements) It is also possible to use a passive matrix type that does not use active elements (active elements). Since it does not use any nonlinear elements, there are fewer manufacturing steps, which reduces manufacturing costs and improves yield. Alternatively, active elements (active elements, non-linear elements) can be used. Since the aperture ratio is not increased, it is possible to achieve low power consumption or high brightness. This can be done.

[0453] The structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. can be done.

[0454] (Sixth embodiment) In this embodiment, a display device including a light-emitting element of one embodiment of the present invention and a display device including the light-emitting element An electronic device having an input device attached thereto will be described with reference to FIGS. 27 to 31. FIG.

[0455] <Touch panel explanation 1> In the present embodiment, an example of an electronic device is a device that combines a display device and an input device. The touch panel 2000 will be described. The case where the .sigma. is included will be described.

[0456] 27(A) and (B) are perspective views of the touch panel 2000. In B), representative components of touch panel 2000 are shown for clarity.

[0457] The touch panel 2000 includes a display device 2501 and a touch sensor 2595 (see FIG. 2). 7(B)). The touch panel 2000 includes a substrate 2510, a substrate 2570, and a substrate The substrate 2510, the substrate 2570, and the substrate 2590 are all However, any one of the substrates 2510, 2570, and 2590 is flexible. Alternatively, one or all of the components may be configured to be non-flexible.

[0458] The display device 2501 has a plurality of pixels on a substrate 2510 and a display device that can supply signals to the pixels. The plurality of wirings 2511 are arranged around the periphery of the substrate 2510. The wire is routed through a cable, part of which forms the terminal 2519. The terminal 2519 is an FPC2509 (1). In addition, the plurality of wirings 2511 are electrically connected to the signal line driver circuit 2503s ( The signal from 1) can be fed to multiple pixels.

[0459] The substrate 2590 is electrically connected to the touch sensor 2595. The plurality of wirings 2598 are routed around the periphery of the substrate 2590. The terminal is electrically connected to the FPC2509(2). In FIG. 27(B), for clarity, the back side of the substrate 2590 (substrate 2510 The electrodes and wiring of the touch sensor 2595 provided on the surface opposite to the touch sensor 2595 are shown by solid lines. .

[0460] As the touch sensor 2595, for example, a capacitance type touch sensor can be applied. The capacitive type includes a surface type electrostatic capacitance type and a projected type electrostatic capacitance type.

[0461] The projected capacitive type is mainly divided into self-capacitance type and mutual capacitance type, which differ mainly in the driving method. The mutual capacitance method is preferable because it allows simultaneous multi-point detection.

[0462] The touch sensor 2595 shown in FIG. 27(B) is a projected capacitive touch sensor. This is a configuration in which the .

[0463] The touch sensor 2595 can detect the proximity or contact of a detection object such as a finger. Various sensors can be applied.

[0464] The projected capacitive touch sensor 2595 has an electrode 2591 and an electrode 2592. The electrode 2591 is electrically connected to one of the plurality of wirings 2598, and the electrode 2592 is It is electrically connected to any other of the plurality of wirings 2598.

[0465] As shown in FIGS. 27(A) and 27(B), the electrodes 2592 are made of a plurality of electrodes repeatedly arranged in one direction. The shape is such that the quadrilaterals are connected at their corners.

[0466] The electrode 2591 is quadrilateral and is repeated in a direction intersecting the direction in which the electrode 2592 extends. are placed.

[0467] The wiring 2594 is electrically connected to the two electrodes 2591 that sandwich the electrode 2592. In this case, it is preferable that the area of ​​the intersection between the electrode 2592 and the wiring 2594 is as small as possible. This reduces the area where no electrodes are provided, reducing variations in transmittance. As a result, the variation in brightness of light passing through the touch sensor 2595 can be reduced. can be done.

[0468] The shapes of the electrodes 2591 and 2592 are not limited to this, and may take various shapes. For example, multiple electrodes 2591 are arranged with as few gaps as possible, and A plurality of electrodes 2592 are provided at intervals so that there is an area where they do not overlap with the electrodes 2591. In this case, a contact between two adjacent electrodes 2592 may be provided. Providing an insulated dummy electrode is preferable because it can reduce the area of ​​the region with different transmittance. .

[0469] <Explanation about the display device> Next, the display device 2501 will be described in detail with reference to FIG. 28(A). ) corresponds to a cross-sectional view taken along the dashed dotted line X1-X2 shown in FIG. 27(B).

[0470] The display device 2501 has a plurality of pixels arranged in a matrix. and a pixel circuit for driving the display element.

[0471] In the following description, a light emitting element that emits white light is applied to a display element. However, the display element is not limited to this. For example, To achieve different colors, light emitting elements with different luminescent colors may be applied.

[0472] The substrate 2510 and the substrate 2570 may have a water vapor permeability of, for example, 1×10 -5 g· m -2 ·day -1 Less than 1 × 10 -6 g·m -2 ·day -1 It is possible that A flexible material can be preferably used. Alternatively, the thermal expansion coefficient of the substrate 2510 and the It is preferable to use a material whose coefficient of thermal expansion is approximately equal to that of the plate 2570. For example, is 1×10 -3 / K or less, preferably 5×10 -5 / K or less, more preferably 1×10 - 5 A material having a solubility of 0.1 kJ / K or less can be suitably used.

[0473] The substrate 2510 has an insulating layer 2510a that prevents impurities from diffusing into the light-emitting element, and a flexible The substrate 2510b and the adhesive layer 2 that bonds the insulating layer 2510a and the flexible substrate 2510b together. The substrate 2570 is a laminate having a layer 510c and a layer 510d. and a flexible substrate 2570b. 2570b and an adhesive layer 2570c that bonds them together.

[0474] The adhesive layer 2510c and the adhesive layer 2570c may be made of, for example, polyester or polyolefin. Polyimide, polycarbonate or acrylic Polyurethane resin, epoxy resin, or silicone resin can be used. Any material containing a resin having a siloxane bond can be used.

[0475] In addition, a sealing layer 2560 is provided between the substrate 2510 and the substrate 2570. It is preferable that the refractive index of the sealing material is larger than that of air. When light is extracted from the layer 2560 side, the sealing layer 2560 can also serve as an optical bonding layer. Cut.

[0476] A sealant may be formed on the outer periphery of the sealing layer 2560. As a result, the area surrounded by the substrate 2510, the substrate 2570, the sealing layer 2560, and the sealant The sealing layer 2560 may have a light emitting element 2550R. An inert gas (nitrogen, argon, etc.) may be filled. In addition, a desiccant may be added to the inert gas. Alternatively, a resin such as acrylic or epoxy may be used. The sealing material may be, for example, an epoxy resin or It is preferable to use glass frit. In addition, the material used for the sealing material is one that is resistant to moisture and acid. It is preferable to use a material that is opaque to the element.

[0477] The display device 2501 also has a pixel 2502R. The pixel 2502R is a light-emitting model. It has a Joule 2580R.

[0478] The pixel 2502R includes a light emitting element 2550R and a power supply for the light emitting element 2550R. The transistor 2502t is a transistor that can The light emitting module 2580R includes a light emitting element 2550R and It has a colored layer 2567R.

[0479] The light emitting element 2550R includes a lower electrode, an upper electrode, and an EL layer between the lower electrode and the upper electrode. The light-emitting element 2550R may be, for example, any of the light-emitting elements described in Embodiments 1 to 3. Optical elements can be applied.

[0480] In addition, a microcavity structure is adopted between the lower electrode and the upper electrode, and at a specific wavelength, The light intensity may be increased.

[0481] Furthermore, when the sealing layer 2560 is provided on the side from which light is extracted, the sealing layer 2560 It contacts the optical element 2550R and the colored layer 2567R.

[0482] The colored layer 2567R is located so as to overlap the light emitting element 2550R. A part of the light emitted by 2550R passes through the colored layer 2567R and is emitted in the direction of the arrow shown in the figure. The light is emitted to the outside of the optical module 2580R.

[0483] Furthermore, the display device 2501 is provided with a light-shielding layer 2567BM in the light-emitting direction. The light-shielding layer 2567BM is provided so as to surround the colored layer 2567R.

[0484] The colored layer 2567R only needs to have a function of transmitting light in a specific wavelength band. For example, a color filter that transmits light in the red wavelength band, a color filter that transmits light in the green wavelength band, A color filter that transmits light in the blue wavelength band, and a color filter that transmits light in the yellow wavelength band. A transparent color filter can be used. Each color filter is made of various materials. The method includes printing, inkjet printing, and etching using photolithography technology. It can be formed by.

[0485] The display device 2501 is also provided with an insulating layer 2521. The insulating layer 2521 is formed to flatten the unevenness caused by the pixel circuit. In addition, the insulating layer 2521 has a function of suppressing diffusion of impurities. This prevents the reliability of the transistor 2502t and the like from being reduced due to the diffusion of impurities. It can be suppressed.

[0486] The light emitting element 2550R is formed above the insulating layer 2521. The lower electrode of 550R is provided with a partition wall 2528 that overlaps the edge of the lower electrode. A spacer for controlling the distance between the substrate 2510 and the substrate 2570 is provided on the partition wall 2528. It may be formed.

[0487] The scanning line driver circuit 2503g(1) includes a transistor 2503t and a capacitor 2503c. The driver circuit and the pixel circuit can be formed on the same substrate in the same process. do.

[0488] Moreover, wiring 2511 capable of supplying signals is provided on the substrate 2510 . A terminal 2519 is provided on the wiring 2511. The terminal 2519 is also provided with an FP C2509(1) is electrically connected. FPC2509(1) also transmits video signals, It has the function of supplying clock signals, start signals, reset signals, etc. 509(1) may have a printed wiring board (PWB) attached.

[0489] In addition, transistors with various structures can be applied to the display device 2501. 28(A) shows an example of a case where a bottom gate transistor is applied. However, the present invention is not limited to this, and for example, a top gate type transistor shown in FIG. The display device 2501 may be configured to use the same.

[0490] In addition, there is no particular limitation on the polarity of the transistor 2502t and the transistor 2503t. There is no fixed definition, and the structure has N-channel and P-channel transistors. A structure consisting of either a P-channel transistor or a P-channel transistor is used. In addition, the crystal structure of the semiconductor film used in the transistors 2502t and 2503t may be For example, an amorphous semiconductor film or a crystalline semiconductor film can be used. In addition, semiconductor materials include semiconductors of group 14 (for example, semiconductors containing silicon). A compound semiconductor (including an oxide semiconductor), an organic semiconductor, etc. can be used. Either or both of the transistors 2502t and 2503t are provided with an energy Oxides with a gap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more The use of a semiconductor is preferable because the off-state current of the transistor can be reduced. The oxide semiconductor includes In-Ga oxide, In-M-Zn oxide (M is Al, G a, Y, Zr, La, Ce, Sn, Hf, or Nd).

[0491] <Explanation about touch sensors> Next, the touch sensor 2595 will be described in detail with reference to FIG. (C) corresponds to a cross-sectional view taken along the dashed dotted line X3-X4 shown in FIG. 27(B).

[0492] The touch sensor 2595 is made up of electrodes 2591 and electrodes 2592 arranged in a staggered pattern on a substrate 2590. 2592, an insulating layer 2593 covering the electrodes 2591 and 2592, and the adjacent electrodes 25 91 and a wiring 2594 that electrically connects them.

[0493] The electrode 2591 and the electrode 2592 are formed using a light-transmitting conductive material. Examples of conductive materials having the formula include indium oxide, indium tin oxide, and indium zinc oxide. Conductive oxides such as zinc oxide, zinc oxide, and zinc oxide doped with gallium can be used. A film containing graphene may also be used. The film containing graphene may be, for example, a film-like The graphene oxide film can be formed by reducing the graphene oxide film formed on the substrate. For example, a method of applying heat can be mentioned.

[0494] For example, a film of a light-transmitting conductive material is formed on the substrate 2590 by sputtering. After that, various patterning techniques such as photolithography are used to remove unnecessary parts. , an electrode 2591 and an electrode 2592 can be formed.

[0495] The insulating layer 2593 may be made of a material such as acrylic resin or epoxy resin. In addition to resins with siloxane bonds such as silicone, silicon oxide, oxynitride, Inorganic insulating materials such as silicon and aluminum oxide can also be used.

[0496] An opening reaching the electrode 2591 is provided in the insulating layer 2593, and a wiring 2594 is adjacent to the opening. The transparent conductive material is used to increase the aperture ratio of the touch panel. Therefore, it can be suitably used for the wiring 2594. A material having higher conductivity than the electrode 2592 is preferable for the wiring 2594 because it can reduce electrical resistance. It can be used appropriately.

[0497] The electrodes 2592 extend in one direction, and a plurality of electrodes 2592 are provided in a stripe pattern. Moreover, the wiring 2594 is provided so as to intersect with the electrode 2592.

[0498] A pair of electrodes 2591 is provided with one electrode 2592 sandwiched therebetween. A pair of electrodes 2591 are electrically connected.

[0499] The plurality of electrodes 2591 are arranged in a direction that is not necessarily perpendicular to one electrode 2592. The angle does not have to be 0 degrees, and may be greater than 0 degrees and less than 90 degrees.

[0500] The wiring 2598 is electrically connected to the electrode 2591 or the electrode 2592. A part of the wiring 2598 functions as a terminal. The wiring 2598 is made of, for example, aluminum. Aluminum, gold, platinum, silver, nickel, titanium, tungsten, chromium, molybdenum, iron, Use of metal materials such as ballast, copper, or palladium, or alloy materials containing such metal materials. can be done.

[0501] An insulating layer covering the insulating layer 2593 and the wiring 2594 is provided, and the touch sensor 2595 may be protected.

[0502] The connection layer 2599 electrically connects the wiring 2598 and the FPC 2509(2). .

[0503] The connection layer 2599 is made of an anisotropic conductive film (ACF). conductive film) and anisotropic conductive paste (ACP) Conductive Paste) can be used.

[0504] <Touch panel explanation 2> Next, details of the touch panel 2000 will be described with reference to FIG. (A) corresponds to a cross-sectional view taken along the dashed dotted line X5-X6 shown in FIG. 27(A).

[0505] The touch panel 2000 shown in FIG. 29(A) is the same as the display device 250 described in FIG. 28(A). 28(C) is attached to the touch sensor 2595.

[0506] The touch panel 2000 shown in FIG. 29(A) is similar to the touch panel 2000 shown in FIG. 28(A) and FIG. 28(C). In addition to the components described above, it has an adhesive layer 2597 and an anti-reflection layer 2567p.

[0507] The adhesive layer 2597 is provided in contact with the wiring 2594. The substrate 2590 is attached to the substrate 2570 so that the sensor 2595 overlaps the display device 2501. The adhesive layer 2597 is preferably transparent. The material 597 can be a thermosetting resin or an ultraviolet curing resin. For example, Acrylic resin, urethane resin, epoxy resin, or siloxane resin may be used. This can be done.

[0508] The anti-reflection layer 2567p is provided at a position overlapping the pixel. For example, a circular polarizing plate can be used.

[0509] Next, for a touch panel having a different configuration from that shown in FIG. 29(A), FIG. 29(B) This will be used to explain.

[0510] FIG. 29(B) is a cross-sectional view of the touch panel 2001. The panel 2001 is a touch panel 2000 shown in FIG. 29(A) and a display device 2501. The location of the touch sensor 2595 is different. Here, the different configurations are explained in detail. The description of the touch panel 2000 is cited for the parts where a similar configuration can be used.

[0511] The colored layer 2567R is located so as to overlap the light emitting element 2550R. The light-emitting element 2550R emits light toward the side where the transistor 2502t is provided. As a result, a part of the light emitted by the light emitting element 2550R passes through the colored layer 2567R, The light is emitted to the outside of light emitting module 2580R in the direction of the arrow shown in the figure.

[0512] The touch sensor 2595 is provided on the substrate 2510 side of the display device 2501. .

[0513] The adhesive layer 2597 is between the substrate 2510 and the substrate 2590 and is in contact with the display device 2501. Stick the Chisensor 2595 together.

[0514] As shown in FIGS. 29(A) and 29(B), the light emitted from the light emitting element is incident on the substrate 2510 side and the It may be emitted through either or both of the substrate 2570 sides.

[0515] <Explanation of how to drive the touch panel> Next, an example of a method for driving a touch panel will be explained with reference to FIGS. 30(A) and 30(B). cormorant.

[0516] FIG. 30(A) is a block diagram showing the configuration of a mutual capacitance type touch sensor. In (A), a pulse voltage output circuit 2601 and a current detection circuit 2602 are shown. In FIG. 30(A), the electrodes 2621 to which the pulse voltage is applied are designated as X1-X6, and the change in current The electrodes 2622 for detecting the change are shown as Y1-Y6, each with six wires. In addition, FIG. 30(A) shows a capacitance 2 formed by overlapping the electrode 2621 and the electrode 2622. 603. The electrodes 2621 and 2622 have functions interchangeable with each other. That's fine.

[0517] The pulse voltage output circuit 2601 is a circuit for applying pulses to the X1-X6 wirings in sequence. When a pulse voltage is applied to the wiring of X1-X6, the voltage that forms the capacitance 2603 An electric field is generated between the electrodes 2621 and 2622. The electric field generated between the electrodes is By using the change in the mutual capacitance of the capacitance 2603, the proximity of the object to be detected or A contact can be detected.

[0518] The current detection circuit 2602 detects the change in the mutual capacitance of the capacitor 2603 between the wires Y1 and Y6. This is a circuit for detecting changes in current. The wiring of Y1-Y6 detects the proximity of the object to be detected, Or, if there is no contact, the detected current value will not change, but the proximity of the object to be detected, or When the mutual capacitance decreases due to contact, a decrease in the current value is detected. The detection may be performed using an integrating circuit or the like.

[0519] Next, FIG. 30(B) shows the input voltage of the mutual capacitance type touch sensor shown in FIG. 30(A). The timing chart of the output waveform is shown in Figure 30(B). In addition, in FIG. 30(B), when no object is detected (non-touched), The two cases shown are when the object is detected (touch) and when the object is detected (touch). (B) shows the waveform of the voltage value corresponding to the current value detected in the wires Y1-Y6. .

[0520] A pulse voltage is applied to the wires X1-X6 in order, and the The waveform in the Y6 wiring changes. When there is no proximity or contact of the object to be detected, X1-X6 The waveforms of Y1-Y6 change uniformly according to the change in the voltage of the wiring. Or, at the contact point, the current value decreases, and the corresponding voltage waveform also changes. do.

[0521] In this way, by detecting the change in mutual capacitance, the proximity or contact of the object to be detected can be detected. It is possible.

[0522] <Sensor circuit explanation> In addition, in FIG. 30(A), only a capacitor 2603 is provided at the intersection of the wiring as a touch sensor. The configuration of a passive matrix touch sensor is shown, but it has a transistor and a capacitor. An active matrix touch sensor may be used. An example of a sensor circuit included in the sensor is shown in FIG.

[0523] The sensor circuit shown in FIG. 31 includes a capacitor 2603, a transistor 2611, and a transistor 2612 and a transistor 2613.

[0524] A signal G2 is applied to the gate of the transistor 2613, and a signal G3 is applied to either the source or the drain of the transistor 2613. A voltage VRES is applied, and the other is connected to one electrode of the capacitor 2603 and the transistor 2611 The transistor 2611 has a source and a drain electrically connected to the gate of the transistor 2611. The source or drain of the transistor 2612 is electrically connected to the voltage VS The transistor 2612 receives a signal G1 at its gate and a signal S at its source or The other electrode of the drain is electrically connected to the wiring ML. The other electrode of the capacitor 2603 is connected to a voltage VS S is given.

[0525] Next, the operation of the sensor circuit shown in Fig. 31 will be described. First, the signal G2 is When a potential is applied to turn on the transistor 2613, the gate of the transistor 2611 is turned on. A potential corresponding to the voltage VRES is applied to the node n to which the signal G2 is connected. When a potential that turns off the transistor 2613 is applied, the potential of the node n Retained.

[0526] Next, the mutual capacitance of the capacitor 2603 changes when a detection object such as a finger approaches or touches the sensor. As a result, the potential of the node n changes from VRES.

[0527] The read operation applies a potential to the signal G1 that turns on the transistor 2612. The current flowing through the transistor 2611 in accordance with the potential of the node n, that is, the current flowing through the wiring ML By detecting this current, the proximity or contact of the object to be detected can be detected. This can be done.

[0528] The transistors 2611, 2612, and 2613 include: It is preferable to use an oxide semiconductor layer as the semiconductor layer in which the channel region is formed. By applying such a transistor to the transistor 2613, the potential of the node n This allows the voltage to be held for a long period of time, and the operation of re-supplying VRES to node n (restart) is performed. This can reduce the frequency of refresh operations.

[0529] The structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. can be done.

[0530] (Embodiment 7) In this embodiment, a display module and an electronic device including a light-emitting element of one embodiment of the present invention will be described. This will be explained with reference to FIGS. 32 to 37.

[0531] <Explanation about the display module> The display module 8000 shown in FIG. 32 includes an upper cover 8001 and a lower cover 8002. Between them, the touch sensor 8004 connected to FPC8003 and the touch sensor 8005 connected to FPC8006 are A display device 8006, a frame 8009, a printed circuit board 8010, and a battery 8011 are included. do.

[0532] The light-emitting element of one embodiment of the present invention can be used for the display device 8006, for example.

[0533] The upper cover 8001 and the lower cover 8002 are connected to the touch sensor 8004 and the display device 8005. The shape and dimensions can be changed appropriately to match the size of 006.

[0534] The touch sensor 8004 is a resistive or capacitive touch sensor mounted on the display device 8 8006. In addition, the display device 8006 can be used as an opposing substrate (sealing substrate). It is also possible to provide a touch sensor function. It is also possible to provide an optical sensor in each pixel to form an optical touch sensor.

[0535] The frame 8009 has a function of protecting the display device 8006 and also a function of preventing the operation of the printed circuit board 8010. It also functions as an electromagnetic shield to block electromagnetic waves generated by the frame. The frame 8009 may also function as a heat sink.

[0536] The printed circuit board 8010 includes a power supply circuit, a signal circuit for outputting a video signal and a clock signal. The power supply circuit is provided with a signal processing circuit. Alternatively, the power source may be a battery 8011 provided separately. This can be omitted if a commercial power source is used.

[0537] In addition, the display module 8000 includes components such as a polarizing plate, a retardation plate, and a prism sheet. It may also be provided in addition.

[0538] <Electronic device instructions> 33(A) to 33(G) are diagrams showing electronic devices. These electronic devices are A body 9000, a display unit 9001, a speaker 9003, operation keys 9005 (power switch, includes an operation switch), a connection terminal 9006, a sensor 9007 (force, displacement, position, speed, Acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electricity Measures field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared 9008, etc. Also, the sensor 9 007 may have a function of measuring biological information such as a pulse sensor or a fingerprint sensor.

[0539] The electronic devices shown in FIGS. 33A to 33G can have various functions. For example, functions to display various information (still images, videos, text images, etc.) on the display, Sensor function, calendar, date or time display function, various software ( It has the function of controlling processing by using a program, wireless communication function, and various functions using wireless communication function. Functions for connecting to computer networks, transmitting various data using wireless communication functions, or receiving the program or data recorded on the recording medium, and It is to be noted that the functions shown in Figs. 33(A) to 33(G) can be implemented. The functions that the electronic device shown in the figure can have are not limited to these, and it may have various functions. Although not shown in FIGS. 33(A) to 33(G), the electronic device may include: The electronic device may have a plurality of display units. The function to take pictures, take videos, and save the images to a recording medium (external or built-in to the camera) ) and a function to display the captured image on the display unit.

[0540] The electronic devices shown in FIGS. 33A to 33G will be described in detail below.

[0541] FIG. 33A is a perspective view showing a mobile information terminal 9100. The display portion 9001 is flexible. The display unit 9001 can be incorporated along the screen. It is equipped with a touch panel, and can be operated by touching the screen with a finger or a stylus. By touching the icon displayed on the display 9001, the application can be started. can.

[0542] 33(B) is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 is For example, the device has one or more functions selected from a telephone, a notebook, an information viewing device, etc. Specifically, it can be used as a smartphone. Although the speaker 9003, the connection terminal 9006, the sensor 9007, etc. are omitted in the illustration, It can be installed in the same position as the mobile information terminal 9100 shown in 33(A). The information terminal 9101 can display text and image information on multiple surfaces. For example, Three operation buttons 9050 (also called operation icons or simply icons) are displayed on the display unit 900. 9051 shown in a dashed rectangle can be displayed on one side of the display unit 90. 01. An example of the information 9051 is an e-mail A display that notifies you of incoming calls, SNS (social networking services), etc. , subject of email or SNS, sender name of email or SNS, date and time, time, There are also displays showing the remaining battery level, the strength of the received signal, etc. Even if you display operation buttons 9050 instead of information 9051 at the displayed position, good.

[0543] The housing 9000 is made of a material such as alloy, plastic, or ceramic. Reinforced plastic can also be used as the plastic. Carbon fiber reinforced resin composites (CFRP), a type of plastic Carbon fiber reinforced plastics (CFRP) has the advantage of being lightweight and corrosion-resistant. Other reinforced plastics include glass fiber reinforced plastics and aramid. Examples of alloys include aluminum alloys. and magnesium alloys, among which are those containing zirconium, copper, nickel, and titanium. Amorphous alloys (also called metallic glasses) have excellent elastic strength. It is an amorphous alloy that has a glass transition region at room temperature and is also called a bulk-solidifying amorphous alloy. It is an alloy that has a substantially amorphous atomic structure. The alloy material is poured into the mold for the housing, and then solidified to form a part of the housing with a bulk-solidified amorphous alloy. Amorphous alloys are formed using zirconium, copper, nickel, titanium, and other materials such as beryllium, silicon, and Silicon, niobium, boron, gallium, molybdenum, tungsten, manganese, iron, cobalt The amorphous alloy may contain, for example, zinc, yttrium, vanadium, phosphorus, or carbon. Not limited to solidification casting, but also includes vacuum deposition, sputtering, electrolytic plating, electroless plating, etc. The amorphous alloy may be formed by the following method. It may contain microcrystals or nanocrystals as long as it maintains a non-metallic state. refers to both complete solid solution alloys, which have a single solid phase structure, and partial solutions, which have two or more phases. By using an amorphous alloy for the housing 9000, a housing with high elasticity can be realized. Therefore, even if the portable information terminal 9101 is dropped, the housing 9000 is made of an amorphous alloy. If there is a mobile information terminal 91, it will return to its original shape even if it is temporarily deformed at the moment of impact. 01 can improve its impact resistance.

[0544] 33(C) is a perspective view showing a portable information terminal 9102. The portable information terminal 9102 is , and has the function of displaying information on three or more surfaces of the display unit 9001. An example is shown in which information 9053 and information 9054 are displayed on different sides. The user of the portable information terminal 9102 stores the portable information terminal 9102 in the breast pocket of his / her clothes. In this state, the display (information 9053 in this case) can be confirmed. The telephone number or name of the caller is displayed in a position that can be observed from above the mobile information terminal 9102. The user can view the display without taking the mobile information terminal 9102 out of his pocket. You can check the call and decide whether to accept it or not.

[0545] 33(D) is a perspective view showing a wristwatch-type portable information terminal 9200. The 9200 is suitable for mobile phone calls, e-mail, document browsing and writing, music playback, and internet communications. It is possible to run various applications such as computer games. The display surface of the display unit 9001 is curved, and the display is performed along the curved display surface. In addition, the portable information terminal 9200 can perform short-distance wireless communication according to a communication standard. For example, by communicating with a wireless headset, handset The mobile information terminal 9200 also has a connection terminal 9006. It has a connector and can directly exchange data with other information terminals. Charging can also be performed via the connection terminal 9006. It may also be possible to supply power wirelessly without going through 6.

[0546] 33(E), (F), and (G) are perspective views showing a foldable portable information terminal 9201. FIG. 33(E) is a perspective view of the portable information terminal 9201 in an unfolded state, and FIG. (F) shows the mobile information terminal 9201 being changed from one of the unfolded state and the folded state to the other. 33(G) is a perspective view of the portable information terminal 9201 in a folded state. The portable information terminal 9201 is highly portable when folded, and is easily portable when unfolded. When the display is turned on, the seamless, wide display area provides excellent visibility of the display. The display unit 9001 of the display device 01 is made up of three housings 9000 connected by hinges 9055. The two housings 9000 are supported by the hinge 9055. This allows the portable information terminal 9201 to be reversibly transformed from an unfolded state to a folded state. For example, the portable information terminal 9201 can be bent with a radius of curvature of 1 mm or more and 150 mm or less. It can be done.

[0547] Furthermore, examples of electronic devices include television sets (televisions or television receivers) (also called "computer"), computer monitors, digital cameras, digital video cameras, Digital photo frames, mobile phones (also called mobile phones or mobile phone devices), goggle-type Displays (head-mounted displays), portable game consoles, portable information terminals, audio playback Examples include live video equipment, large gaming machines such as pachinko machines, etc.

[0548] Furthermore, the electronic device of one embodiment of the present invention may include a s...

Claims

1. A light-emitting element having a light-emitting layer, the light-emitting layer includes a first organic compound, a second organic compound, and a guest material; the first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton, a weight ratio of the content of 3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazole to the second organic compound in the light-emitting layer of 0.01 or less;

2. A light-emitting element having a light-emitting layer, the light-emitting layer includes a first organic compound, a second organic compound, and a guest material; the first organic compound has at least one of a pyridine skeleton, a diazine skeleton, and a triazine skeleton; a weight ratio of the content of 3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazole to the second organic compound in the light-emitting layer of 0.01 or less;

3. In claim 1 or 2, The light-emitting device is characterized in that the stabilization energy at the time of dissociation of the NH bond in the 3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazole is less than 0 eV.

4. In any one of claims 1 to 3, a content of an organic compound including a nitrogen-containing five-membered heterocyclic skeleton in which a nitrogen atom has an unpaired electron or an aromatic amine skeleton in which a nitrogen atom has an unpaired electron in the light-emitting layer, the content of the organic compound being 0.03 or less in weight ratio to the first organic compound.

5. In any one of claims 1 to 4, a weight ratio of the organic compound in which a hydrogen atom is further bonded to the first organic compound to the first organic compound in the light-emitting layer to the first organic compound of 0.03 or less;

6. In any one of claims 1 to 5, a content of an organic compound including a nitrogen-containing five-membered heterocyclic skeleton in which a nitrogen atom has an unpaired electron or an aromatic amine skeleton in which a nitrogen atom has an unpaired electron in the light-emitting layer relative to the second organic compound is 0.01 or less in terms of weight ratio.

7. In any one of claims 1 to 6, a weight ratio of the organic compound in which a hydrogen atom is further bonded to the first organic compound to the second organic compound in the light-emitting layer of 0.01 or less;

8. In any one of claims 1 to 7, The guest material has a function of converting triplet excitation energy into luminescence. A light-emitting element characterized by:

9. In any one of claims 1 to 8, The guest material comprises iridium. A light-emitting element characterized by:

10. The light-emitting element according to any one of claims 1 to 9, at least one of a color filter or a transistor; A display device having:

11. The display device according to claim 10; At least one of a housing or a touch sensor; An electronic device having:

12. The light-emitting element according to any one of claims 1 to 9, At least one of a housing or a touch sensor; A lighting device having:

Images