Light-emitting devices, light-emitting apparatus, light-emitting modules, electronic equipment and lighting apparatus

Abstract

We provide long-life light-emitting devices. We provide highly reliable light-emitting devices. [Solution] First electrode, first light-emitting layer, first layer, second layer, third layer, second light-emitting layer This is a light-emitting device having a first electrode and a second electrode stacked in this order. The first layer is the first electrode It has an organic compound and a first substance. The second layer has a second organic compound. The third The layer has a second substance. The first organic compound is an electron transport material. The first substance is The first organic compound is a metal salt, metal oxide, or organometallic salt. The second organic compound is an electron transport material. The second material is an electron-injection material. The second layer is more of the first material than the first layer. The concentration is low.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a light-emitting device (also called a light-emitting element), a light-emitting apparatus, a light-emitting module, and an electric light-emitting device. This relates to sub-devices and lighting equipment.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. For example, semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, Input devices (e.g., touch sensors), input / output devices (e.g., touch panels), and Examples of these driving methods, or methods for manufacturing them, can be given. [Background technology]

[0003] Organic electroluminescence (EL: Electro Luminescence) Research and development of light-emitting devices (also called organic EL devices or organic EL elements) using elephants are thriving. It is being carried out. The basic configuration of an organic EL device is a luminescent organic material between a pair of electrodes. It consists of a layer containing a composite material (hereinafter also referred to as the light-emitting layer) sandwiched in between. By applying pressure, light emission can be obtained from luminescent organic compounds.

[0004] Examples of luminescent organic compounds include compounds that convert singlet excited states into light emission (fluorescent compounds). Compounds (also called fluorescent substances) and compounds that convert triplet excited states into light emission (phosphorescent compounds) Examples include compounds (also called phosphorescent substances). Patent Document 1 lists the following as phosphorescent compounds: Organometallic complexes with lydium as the central metal have been disclosed.

[0005] Organic EL devices are easy to make thin and light, and can respond quickly to input signals. It has features such as being drivable using a DC low voltage power supply and is suitable for a display device.

[0006] In addition, since the organic EL device can be formed in a film shape, planar light emission can be obtained. Therefore, a large-area light-emitting device can be easily formed. This is a characteristic that is difficult to obtain with point light sources typified by LEDs (light-emitting diodes) and line light sources typified by fluorescent lamps. Therefore, the organic EL device also has high utility value as a surface light source applicable to lighting devices and the like.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] One aspect of the present invention aims to provide a long-life light-emitting device. Or, one aspect of the present invention aims to provide a highly reliable light-emitting device. Or, one aspect of the present invention aims to provide a light-emitting device with a low driving voltage. Also one aspect of the present invention aims to provide a light-emitting device with high luminous efficiency.

[0009] Note that the description of these problems does not prevent the existence of other problems. One aspect of the present invention is not necessarily required to solve all of these problems. It is possible to extract other problems from the description of the specification, drawings, and claims.

Means for Solving the Problems

[0010] A light-emitting device according to one aspect of the present invention comprises a first electrode, a first light-emitting layer, a first layer, a second layer, and This light-emitting device has three layers, a second light-emitting layer, and a second electrode stacked in this order. The first layer comprises a first organic compound and a first substance. The second layer comprises a second organic compound. It has a compound. The third layer has the second substance. The first organic compound is an electron transport material. The first substance is a metal, a metal salt, a metal oxide, or an organometallic salt. The second is The first compound is an electron-transporting material. The second substance is an electron-injecting material. The second layer is The concentration of the first substance is lower in the second layer compared to the first layer. In particular, the second layer does not contain the first substance. It is preferable.

[0011] Preferably, the first organic compound and the second organic compound are the same organic compound.

[0012] The third layer preferably further comprises a third organic compound. The third organic compound is It is preferable that the material is an electron transport material. The third organic compound is the first organic compound and the second It is preferable that it is the same organic compound as at least one of the organic compounds.

[0013] The first substance is an organometallic complex containing an alkali metal or alkaline earth metal. It is preferable.

[0014] The first substance comprises a ligand having nitrogen and oxygen, and an alkali metal or alkaline earth metal. It is preferable that the organometallic complex has the following properties.

[0015] The first substance comprises a quinolinol ligand and an alkali metal or alkaline earth metal. It is preferable that it be an organometallic complex.

[0016] The second substance preferably contains alkali metals, alkaline earth metals, or rare earth metals. It's nice.

[0017] The first organic compound has a HOMO level of -6.0 eV or higher and an electric field strength [V / cm²]. The electron mobility at which the square root of ] is 600 is 1 × 10 -7 cm 2 / Vs or more 5×10 -5 c m 2 It is preferable that it is less than or equal to / Vs.

[0018] The first layer has a first region on the side of the first light-emitting layer and a second region on the side of the second light-emitting layer. This is preferable. The first region and the second region are defined by the concentration ratio of the first organic compound to the first substance. It is preferable that the second region has a higher concentration of the first substance than the first region. A lower value is preferable.

[0019] A light-emitting device according to one aspect of the present invention preferably further has a hole injection layer. The injection layer is preferably located between the first electrode and the first light-emitting layer. The hole injection layer is the It is preferable to have compound 1 and compound 2. The first compound is a compound of the second compound. It is preferable that it has electron-accepting properties. The HOMO level of the second compound is -5.7e It is preferable that the temperature is between V and -5.4eV.

[0020] A light-emitting device according to one aspect of the present invention preferably further has a first hole transport layer. The first hole transport layer is preferably located between the hole injection layer and the first light-emitting layer. The hole transport layer preferably has a third compound. The HOMO level of the third compound is Preferably, the value is below the HOMO level of the second compound. The difference between the energy level and the HOMO level of the second compound is preferably within 0.2 eV. Compound 2 and Compound 3 are, respectively, a carbazole skeleton, a dibenzofuran skeleton, and a dibenzofuran skeleton. It is preferable that it has at least one of the following skeletons: a benzothiophene skeleton and an anthracene skeleton. It's nice.

[0021] A light-emitting device according to one aspect of the present invention preferably further comprises a second hole transport layer. Preferably, the second hole transport layer is located between the first hole transport layer and the first light-emitting layer. The second hole transport layer preferably has a fourth compound. The HOMO of the fourth compound The level is preferably lower than the HOMO level of the third compound. The compound and the fourth compound each consist of a carbazole skeleton, a dibenzofuran skeleton, and a dibe It is preferable that it has at least one of the following skeletons: anzothiophene skeleton and anthracene skeleton. stomach.

[0022] The first light-emitting layer preferably has a light-emitting material that emits blue light.

[0023] The first light-emitting layer preferably has a fluorescent light-emitting material that emits blue light.

[0024] One aspect of the present invention is a light-emitting device having any of the above configurations, and one of a transistor and a substrate. It is a light-emitting device having both or both.

[0025] One aspect of the present invention has the above-mentioned light-emitting device and a flexible printed circuit board (Flexi A Printed Circuit (hereinafter referred to as FPC) or TCP (Turbo Printed Circuit) Modules with connectors such as pe Carrier Package attached, Alternatively, COG (Chip On Glass) or COF (Chip On Fi) Light-emitting modules such as light-emitting modules on which integrated circuits (ICs) are mounted using the lm (lm) method, etc. Yes. Furthermore, one embodiment of the present invention includes a light-emitting module having only one of the connector and the IC. It is acceptable to have both, or to possess both.

[0026] One aspect of the present invention includes the above-mentioned light-emitting module, an antenna, a battery, a housing, a camera, and a speaker. An electronic device having at least one of a microphone, a microphone, and an operating button.

[0027] One aspect of the present invention comprises a light-emitting device having any of the above configurations, a housing, a cover, and a support base. A lighting device having at least one of the following: [Effects of the Invention]

[0028] According to one aspect of the present invention, a long-life light-emitting device can be provided. Or, according to one aspect of the present invention A more reliable light-emitting device can be provided. Alternatively, according to one aspect of the present invention, the drive power A low-pressure light-emitting device can be provided. Alternatively, according to one aspect of the present invention, a light-emitting device with high luminous efficiency can be provided. We can provide optical devices.

[0029] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention is It is not necessarily required to have all of these effects. It is possible to extract effects other than those listed above. [Brief explanation of the drawing]

[0030] [Figure 1] Figures 1A to 1D show examples of light-emitting devices. [Figure 2]Figures 2A to 2D illustrate the concentration of the first substance in the first layer. Figures 2E and 2F illustrate the concentration of the first substance in the first and second layers, respectively. [Figure 3] Figure 3A is a top view showing an example of a light-emitting device. Figures 3B and 3C are cross-sectional views showing an example of a light-emitting device. [Figure 4] Figures 4A to 4D are cross-sectional views showing an example of a light-emitting device. [Figure 5] Figure 5A is a top view showing an example of a light-emitting device. Figure 5B is a cross-sectional view showing an example of a light-emitting device. Figures 5C and 5D are cross-sectional views showing an example of a transistor. [Figure 6] Figures 6A to 6D show examples of electronic devices. [Figure 7] Figures 7A to 7F show examples of electronic devices. [Figure 8] Figures 8A to 8C show examples of electronic devices. [Figure 9] Figures 9A and 9B show light-emitting devices of the embodiment. [Figure 10] Figure 10 shows the brightness-current efficiency characteristics of the light-emitting device of Example 1. [Figure 11] Figure 11 shows the voltage-current characteristics of the light-emitting device of Example 1. [Figure 12] Figure 12 shows the emission spectrum of the light-emitting device of Example 1. [Figure 13] Figure 13 shows the results of the reliability test of the light-emitting device in Example 1. [Figure 14] Figure 14 shows the results of the reliability test of the light-emitting device in Example 1. [Figure 15] Figure 15 shows the brightness-current efficiency characteristics of the light-emitting device of Example 2. [Figure 16] Figure 16 shows the voltage-current characteristics of the light-emitting device of Example 2. [Figure 17] Figure 17 shows the emission spectrum of the light-emitting device of Example 2. [Figure 18]Figure 18 shows the results of the reliability test of the light-emitting device in Example 2. [Figure 19] Figure 19 shows the results of the reliability test of the light-emitting device in Example 2. [Modes for carrying out the invention]

[0031] Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. Without departing from the spirit and scope of the present invention, its form and details may be modified in various ways. It will be easily understood by those skilled in the art to obtain this. Therefore, the present invention is as shown in the embodiments below. The interpretation is not limited to the content stated herein.

[0032] In the configuration of the invention described below, the same part or part having a similar function is used. The same symbol is used consistently across different drawings, and explanations of its repetition are omitted. When referring to a function, the same hatch pattern may be used, and a specific symbol may not be assigned.

[0033] Furthermore, the position, size, and scope of each component shown in the drawings are, for the sake of ease of understanding, actually The location, size, and range may not be described. Therefore, the disclosed invention must always Furthermore, it is not limited to the location, size, scope, etc., disclosed in the drawings.

[0034] Furthermore, the words "membrane" and "layer" may differ depending on the context or situation. And they can be interchanged. For example, the term "conductive layer" can be replaced with "conductive film". It is possible to change the term to this. Or, for example, the term "insulating film" can be changed to It is possible to change the term to "insulating layer".

[0035] (Embodiment 1) In this embodiment, a light-emitting device according to one aspect of the present invention will be described using Figures 1 and 2. .

[0036] A light-emitting device according to one aspect of the present invention comprises a first electrode, a first light-emitting layer, a first layer, a second layer, and The first layer is a first light-emitting layer and a second electrode, which are stacked in this order. It has an organic compound and a first substance. The second layer has a second organic compound. The third The layer has a second substance. The first organic compound and the second organic compound are each electrically These are materials with high electron transport properties (also called electron transport materials). The first type of material is a metal or metal salt. The second substance is a metal oxide or organometallic salt. It is also called a property material.

[0037] A light-emitting device according to one aspect of the present invention is such that holes are easily injected into the first light-emitting layer, and electrons The configuration makes injection difficult. Holes are easily injected from the first electrode side, and the second electrode The amount of electrons injected into the light-emitting layer from the side is suppressed, resulting in the light-emitting layer becoming electron-rich. This can be suppressed. And as time passes, electrons are injected into the light-emitting layer, increasing the brightness. The brightness increases, and this increase in brightness can offset the initial degradation. Initial degradation is suppressed, Reliability can be improved by using light-emitting devices with extremely long operating lifetimes.

[0038] Here, a first layer having a first substance (metal, metal salt, metal oxide, or organometallic salt) When a third layer having a second substance (electron injection material) is provided in contact with the first layer, the driving voltage The performance of the light-emitting device may deteriorate, for example, due to an increase in certain parameters.

[0039] Therefore, in a light-emitting device according to one aspect of the present invention, a second layer is provided between the first layer and the third layer. The second layer is a layer having a second organic compound (electron transport material). It has the characteristic of having a lower concentration of the first substance than the first layer. Using such a second layer By doing so, the characteristics of the light-emitting device can be improved. Specifically, by adding to the light-emitting device... This suppresses the rise in drive voltage, extends the drive life, and improves reliability.

[0040] In particular, it is preferable that the second layer does not contain the first substance. That is, in this specification, etc. If the second layer has a lower concentration of the first substance than the first layer, then the second layer is the first substance. This includes compositions that do not include quality.

[0041] One embodiment of the present invention is a light-emitting device having a tandem structure in which multiple light-emitting units are stacked. Specifically, a light-emitting device according to one aspect of the present invention includes at least a first light-emitting layer. It has two light-emitting units: a unit and a light-emitting unit that includes a second light-emitting layer. Dem-structured light-emitting devices have higher current efficiency compared to single-structured light-emitting devices. The current required to illuminate at a single brightness level is small. Therefore, the lifespan of the light-emitting device is long. This can increase reliability.

[0042] When manufacturing a display device using a light-emitting device, a common light-emitting layer is used for the subpixels of each color. A light-emitting device with a luminescent structure is provided, and a color filter, a color conversion layer, and a micro-optical resonator (micro By combining it with at least one of the (clo-cavity) structures, a full-color display table can be created. A display device can be manufactured.

[0043] When depositing different light-emitting layers on each subpixel of each color, the opening of the metal mask is positioned at the desired location. High precision in placement (also called alignment precision) is required, especially for high-resolution displays. The device has a high pixel density and requires extremely high alignment accuracy. Also, a metal mask... Due to the deflection, the film is formed over a wider area than the desired region, making it difficult to use on large substrates. Hiring them is difficult.

[0044] On the other hand, a display device capable of full-color display can be fabricated using a light-emitting device according to one aspect of the present invention. In this case, the process of depositing a different light-emitting layer on each subpixel of each color is unnecessary. This enables the highly productive manufacturing of high-definition and large-scale display devices.

[0045] [Configuration of the light-emitting device] Figures 1A to 1D show a light-emitting device according to one embodiment of the present invention.

[0046] The light-emitting device shown in Figure 1A consists of a first electrode 1101, a functional layer 1105a, and a light-emitting layer 1113. a, first layer 1121, second layer 1122, third layer 1123, functional layer 1105b, light emission It has a layer 1113b, a functional layer 1105c, and a second electrode 1103.

[0047] In this specification, etc., between a pair of electrodes (first electrode 1101 and second electrode 1103) Multiple layers are provided (in Figure 1A, functional layer 1105a, light-emitting layer 1113a, first layer 11 21, second layer 1122, third layer 1123, functional layer 1105b, light-emitting layer 1113b, and The functional layer 1105c is sometimes collectively referred to as the EL layer.

[0048] In this embodiment, the first electrode 1101 functions as the anode, and the second electrode 1103 functions as the cathode. Let's explain using an example of how it functions. The first electrode functions as the cathode, and the second electrode If 1103 functions as the anode, the stacking order of the EL layers will be reversed.

[0049] Hole injection is performed in functional layer 1105a, functional layer 1105b, and functional layer 1105c, respectively. Layers, hole transport layer, electron transport layer, electron injection layer, hole blocking layer, electron blocking layer, and charge At least one layer, such as a generation layer, can be used.

[0050] The light-emitting device shown in Figure 1A includes a light-emitting unit containing a light-emitting layer 1113a, and a light-emitting layer 1113 A light-emitting device having a tandem structure comprising a light-emitting unit including b. A charge generation region exists between the first electrode 1101 and the second electrode. When a voltage is applied to electrode 1103, electrons are injected into one of the two light-emitting units, and the other... It has the function of injecting holes. Therefore, in Figure 1A, the first electrode 110 When a voltage is applied to electrode 1 such that its potential is higher than that of the second electrode 1103, the charge generation region is reached. Electrons are injected into the light-emitting unit including the light-emitting layer 1113a, and light emission including the light-emitting layer 1113b is released. Holes are injected into the unit.

[0051] The light-emitting layer 1113a and the light-emitting layer 1113b each contain a light-emitting substance and multiple organic compounds, respectively. The combination of elements is appropriate to obtain fluorescence or phosphorescence at the desired wavelength. This is possible. The light-emitting layer 1113a and the light-emitting layer 1113b are configured to emit light of the same color. It is also possible to have a configuration in which each emits light of a different color. The materials will be discussed later.

[0052] <First layer> The first layer 1121 has a first organic compound and a first substance.

[0053] The first organic compound is an electron transporting material. The electron transporting material has higher electron transportability than hole transportability. It is preferable that the highest occupied molecular orbital level (HOMO level) of the first organic compound is -6.0 eV or more.

[0054] It is preferable that the first organic compound has an anthracene skeleton, and more preferably has an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing 5-membered ring skeleton. The nitrogen-containing 5-membered ring skeleton includes a pyrazole ring, an imidazole ring, an oxazole ring, etc. It is preferable that the first organic compound has an anthracene skeleton, and more preferably has an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing 5-membered ring skeleton. The nitrogen-containing 5-membered ring skeleton includes a pyrazole ring, an imidazole ring, an oxazole ring, etc.

[0055] The electron mobility of the first organic compound at the square root of the electric field strength [V / cm] of 600 is preferably 1×10 cm / Vs or more and 1×10 cm / Vs or less, and more preferably 1×10 cm / Vs or more and 5×10 cm / Vs or less. ×10 -7 cm 2 / Vs or more and 1×10 -5 cm 2 / Vs or less, and more preferably 1× 10 -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less.

[0056] It is preferable that the electron mobility of the first organic compound at the square root of the electric field strength [V / cm] of 600 is smaller than the electron mobility of the host material of the light emitting layer 1113a at the square root of the electric field strength [V / cm] of 600. By reducing the electron transportability in the first layer 1121, the amount of electrons injected into the light emitting layer 1113a can be controlled, and it is possible to prevent the light emitting layer 1113a from being in an electron-excessive state. It is preferable that the electron mobility of the first organic compound at the square root of the electric field strength [V / cm] of 600 is smaller than the electron mobility of the host material of the light emitting layer 1113a at the square root of the electric field strength [V / cm] of 600. By reducing the electron transportability in the first layer 1121, the amount of electrons injected into the light emitting layer 1113a can be controlled, and it is possible to prevent the light emitting layer 1113a from being in an electron-excessive state. It is preferable that the electron mobility of the first organic compound at the square root of the electric field strength [V / cm] of 600 is smaller than the electron mobility of the host material of the light emitting layer 1113a at the square root of the electric field strength [V / cm] of 600. By reducing the electron transportability in the first layer 1121, the amount of electrons injected into the light emitting layer 1113a can be controlled, and it is possible to prevent the light emitting layer 1113a from being in an electron-excessive state. It is preferable that the electron mobility of the first organic compound at the square root of the electric field strength [V / cm] of 600 is smaller than the electron mobility of the host material of the light emitting layer 1113a at the square root of the electric field strength [V / cm] of 600. By reducing the electron transportability in the first layer 1121, the amount of electrons injected into the light emitting layer 1113a can be controlled, and it is possible to prevent the light emitting layer 1113a from being in an electron-excessive state. It is preferable that the electron mobility of the first organic compound at the square root of the electric field strength [V / cm] of 600 is smaller than the electron mobility of the host material of the light emitting layer 1113a at the square root of the electric field strength [V / cm] of 600. By reducing the electron transportability in the first layer 1121, the amount of electrons injected into the light emitting layer 1113a can be controlled, and it is possible to prevent the light emitting layer 1113a from being in an electron-excessive state.

[0057] It is preferable that the first organic compound has an anthracene skeleton, and more preferably has an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing 5-membered ring skeleton. The nitrogen-containing 5-membered ring skeleton includes a pyrazole ring, an imidazole ring, an oxazole ring, etc. It is preferable that the first organic compound has an anthracene skeleton, and more preferably has an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing 5-membered ring skeleton. The nitrogen-containing 5-membered ring skeleton includes a pyrazole ring, an imidazole ring, an oxazole ring, etc. It is preferable that the first organic compound has an anthracene skeleton, and more preferably has an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing 5-membered ring skeleton. The nitrogen-containing 5-membered ring skeleton includes a pyrazole ring, an imidazole ring, an oxazole ring, etc. Having a nitrogen-containing five-membered ring skeleton that includes two complex atoms in the ring, such as a thiazole ring or a thiazole ring. That is particularly preferable.

[0058] For example, the first organic compound is 2-{4-[9,10-di(naphthalene-2-yl )-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: Z ADN), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthrace (Abbreviation: αN-βNPAnth), 9-[4-(10-phenyl-9-anthracenyl) )phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl- 9-Anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDB) Examples include CzPA.

[0059] Other examples of the first organic compound include electron transport materials that can be used in the light-emitting layer described later. Organic compounds (host materials), etc., that can be used in combination with materials and fluorescent luminescent substances. You can use it.

[0060] The first substance is a metal, a metal salt, a metal oxide, or an organometallic salt.

[0061] Examples of metals include alkali metals, alkaline earth metals, and rare earth metals. Examples include Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba.

[0062] Examples of metal salts include halides of the above-mentioned metals and carbonates of the above-mentioned metals. Specifically, LiF, NaF, KF, RbF, CsF, MgF2, CaF2, SrF2 , BaF2, LiCl, NaCl, KCl, RbCl, CsCl, MgCl2, CaCl Examples include SrCl2, BaCl2, Li2CO3, and Cs2CO3.

[0063] Examples of metal oxides include oxides of the above-mentioned metals. Specifically, Li2O, Examples include Na2O, Cs2O, MgO, and CaO.

[0064] Examples of organometallic salts include organometallic complexes.

[0065] The first substance is an organometallic complex containing an alkali metal or alkaline earth metal. It is preferable.

[0066] The first substance comprises a ligand having nitrogen and oxygen, and an alkali metal or alkaline earth metal. It is preferable that the organometallic complex has the following properties.

[0067] The first substance comprises a quinolinol ligand and an alkali metal or alkaline earth metal. It is preferable that it be an organometallic complex.

[0068] Examples of the above organometallic complexes include 8-(quinolinolato)lithium (abbreviation: Liq) and 8-(quinolinolato). (Nolinolato)sodium (abbreviation: Naq), 8-(quinolinolato)potassium (abbreviation: Kq) ), (8-quinolinolato)magnesium (abbreviation: Mgq2), (8-quinolinolato)zinc Examples include (abbreviated as Znq2).

[0069] Liq is particularly preferred as the first substance.

[0070] The first layer 1121 has a first region on the light-emitting layer 1113a side and a second region on the light-emitting layer 1113b side It may have regions. The first region and the second region are the first organic compound and the first substance. It is preferable that the concentration ratios of the substances are different. For example, the second region has a higher concentration of the substance than the first region. A low concentration of the substance is preferable.

[0071] <Second Layer> The second layer 1122 contains a second organic compound.

[0072] The second organic compound is an electron transport material. It can be used as the second organic compound. The material used is similar to the material that can be used for the first organic compound.

[0073] The first organic compound and the second organic compound may be the same organic compound, or they may be different from each other. It may also be an organic compound.

[0074] The second layer preferably has a lower concentration of the first substance compared to the first layer. In particular, the second layer It is preferable that the first substance is not included.

[0075] By providing a second layer 1122 between the first layer 1121 and the third layer 1123, the third The electron injection from layer 1123 to the second layer 1122, and further to the first layer 1121, is improved. The driving voltage of the light-emitting device can be reduced.

[0076] In a configuration where the first layer 1121 and the third layer 1123 are in contact, the second substance (or second material) The metals present in the material may not diffuse easily into the first layer 1121. By providing a second layer 1122 between the third layer 1123 and the third layer 1123, the third layer 1123 is included The second substance (or the metal contained in the second substance) becomes more easily diffused into the second layer 1122. The driving voltage of the light-emitting device can be reduced. This improves the reliability of the light-emitting device. It can improve.

[0077] <Third Layer> The third layer 1123 has the second substance.

[0078] The second type of material is an electron-injection material.

[0079] Examples of electron-injectable materials include alkali metals, alkaline earth metals, rare earth metals, and these. Compounds can be used. Examples of alkali metals, alkaline earth metals, and rare earth metals include: For example, lithium, cesium, magnesium, calcium, erbium, ytterbium Examples include alkali metal compounds and alkaline earth metal compounds. Examples include compounds and rare earth metal compounds. Examples of such compounds include metal oxides and metal salts. Specifically, for example, metal oxides such as lithium oxide (Li2O), lithium carbonate Examples include carbonates such as um (Li2CO3) and cesium carbonate (Cs2CO3). Electrons Electride may be used as the injectable material. Examples of electride include: Examples include substances obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum.

[0080] The third layer 1123 may further have a third organic compound. The substance preferably exhibits electron-donating properties (donor properties) toward the third organic compound.

[0081] The third organic compound is an electron transport material. It can be used as the third organic compound. The material used is similar to the material that can be used for the first organic compound.

[0082] The third organic compound and the first organic compound may be the same organic compound, or they may be different from each other. It may also be an organic compound. Similarly, the third organic compound and the second organic compound are the same It may be a single organic compound, or it may be a set of different organic compounds.

[0083] Figures 1B and 1C show functional layer 1105a and functional layer 1105b in Figure 1A, respectively. This is an example that specifically illustrates the functional layer 1105c.

[0084] The light-emitting device shown in Figure 1B consists of a first electrode 1101, a hole injection layer 1111a, and a hole transport layer. 1112a, light-emitting layer 1113a, first layer 1121, second layer 1122, third layer 112 3. Hole injection layer 1111b, hole transport layer 1112b, light emission layer 1113b, electron transport layer 11 It has 14b, an electron injection layer 1115b, and a second electrode 1103.

[0085] The hole injection layer 1111a preferably contains a first compound and a second compound.

[0086] The first compound is an electron-accepting material, and is related to the second compound. It has electron-accepting properties.

[0087] The second compound is a hole-transporting material. Hole-transporting materials are materials that are more efficient at transporting holes than electrons. expensive.

[0088] The second compound is preferably given a relatively low (deep) highest occupied orbital level (HOMO level). Specifically, the HOMO level of the second compound is between -5.7 eV and -5.4 eV. It is preferable that the HOMO level of the second compound is relatively low, which is beneficial for the hole transport layer 11 This facilitates the injection of holes into 12a, which is preferable.

[0089] The first compound is an electron-withdrawing group (especially halogen groups such as fluoro groups or cyano groups). Organic compounds containing these compounds can be used.

[0090] Examples of the first compound include quinodimethane derivatives, chloranil derivatives, and hexaazato. Organic acceptors such as riphenylene derivatives can be used. 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: HAT-CN), 1,3,4,5,7, 8-Hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2 -(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H Examples include (-pyrene-2-ylidene)malononitrile, etc. In particular, HAT-CN Compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple complex atoms, such as the one shown, are thermally It is stable and desirable. Also, electron-withdrawing groups (especially halogen groups such as fluoro groups and cyano groups) Radialene derivatives having [3] are preferred because they have very high electron-accepting properties. Examples of radialene derivatives having the group [3] include α,α',α''-1,2,3- Cyclopropane triylidenates[4-cyano-2,3,5,6-tetrafluorobene] Zenacetonitrile, α,α',α''-1,2,3-cyclopropane triirident RIS[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzene Cetonitrile, α,α',α''-1,2,3-cyclopropanetriylidenes[ Examples include 2,3,4,5,6-pentafluorobenzeneacetonitrile.

[0091] The second compound preferably has a hole-transporting skeleton. The HOMO level of the hole transport material does not become too high (shallow), carbazole skeleton, gibberellin An lenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton are preferred.

[0092] The second compound has a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and It is preferable to have at least one of the anthracene skeleton. The hole transport material is Aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, naphth Aromatic monoamines having a talene ring, or a 9-fluorenyl group via an arylene group The amine may also be an aromatic monoamine bonded to the nitrogen atom.

[0093] If the second compound has an N,N-bis(4-biphenyl)amino group, a long-lived luminescence This is preferable because it allows for the creation of a vise.

[0094] A second compound is, for example, N-(4-biphenyl)-6,N-diphenylbenzo[ b)Naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis( 4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (Abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2- d]Fran-8-yl-4''-phenyltriphenylamine (abbreviation: BnfBB1BP) ), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-a Min (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naph To[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4 -Biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBAB) nf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]- 4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothio Fen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA) 1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation) :BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyl Triphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6; 1'-Binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4 '-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviated) Name: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naph Tyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenylamine Nyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA) (βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl) Triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4' '-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB) ), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenyl Amine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-na Phthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3 -biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltrif Phenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4 -(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBi) AβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αN BA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1) BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl [4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-f [phenyl-9H-carbazole-9-yl)phenyl]tris(1,1'-biphenyl-4 -yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9- [Il)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenyl Luamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole] -3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobyl (9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1 '-biphenyl]-4-yl)-9,9'-spirobio[9H-fluorene]-2-amine (Abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9 '-Spirobi[9H-Fluorene]-4-amine (abbreviation: BBASF(4)), N-(1 ,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl) Lu)-9,9'-spirobio(9H-fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibe Nzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl] -N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine n (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluorene-9) -yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenyl) Nylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl Lu-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (Abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole) -3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4 ''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: P CBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole) -3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl )-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated) Name: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole- 3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBAS) F), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9- Phenyl-9H-carbazole-3-yl)phenyl]-9H-fluoren-2-amine (Abbreviation: PCBBiF), 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl 4-(10-phenyl-9-anthri) (abbreviation: PCzN2), 4-(10-phenyl-9-anthri) (Lu)-4'-(9-phenyl-9H-fluoren-9-yl)triphenylamine (abbreviation) Examples include :FLPAPA).

[0095] The hole transport layer 1112a shown in Figure 1B transports the holes injected by the hole injection layer 1111a. This is the layer that transports to the light-emitting layer 1113a.

[0096] The hole transport layer 1112a preferably contains a third compound.

[0097] The third compound is a hole-transporting material. As a hole-transporting material, it is used in the second compound. A hole-transporting material that can transport holes can be used.

[0098] The HOMO level of the third compound is preferably less than or equal to the HOMO level of the second compound. The difference between the HOMO level of the third compound and the HOMO level of the second compound is 0.2 eV. It is preferable that it be within a certain range.

[0099] The second and third compounds each consist of a carbazole skeleton and a dibenzofuran skeleton, respectively. It is preferable that it has at least one of the dibenzothiophene skeleton and the anthracene skeleton. It seems so.

[0100] The second and third compounds share the same hole-transporting skeleton (particularly the dibenzofuran skeleton). This is preferable because it allows for smoother hole injection.

[0101] It is preferable that the second and third compounds are the same, as this allows for smoother hole injection. It seems so.

[0102] The hole injection layer 1111b has the function of facilitating the injection of holes into the hole transport layer 1112b. .

[0103] The hole injection layer 1111b may contain the first compound and the second compound described above. Furthermore, it may have a material with high hole injection potential (hole injection material), as described later.

[0104] The hole transport layer 1112b receives the holes injected by the hole injection layer 1111b into the light-emitting layer 111 This is the layer to be transported to 3b.

[0105] The hole transport layer 1112b preferably has a hole transport material. Therefore, a hole-transporting material that can be used in the second compound can be used. It may also have other hole-transporting materials as described later.

[0106] The electron transport layer 1114b receives electrons injected by the electron injection layer 1115b into the light-emitting layer 111 This is the layer to be transported to 3b.

[0107] The electron transport layer 1114b preferably has an electron transport material. Therefore, an electron-transporting material that can be used in the first organic compound can be used.

[0108] The electron injection layer 1115b has the function of facilitating electron injection into the EL layer. Second electrode 1 The work function value of the material used in 103 and the lowest unoccupied orbital of the material used in the electron injection layer 1115b. The difference between the current level (LUMO level) and the next level should preferably be small (within 0.5 eV).

[0109] The electron injection layer 1115b preferably has an electron injection material. Therefore, an electron-injectable material that can be used as the second substance can be used. Layer 1115b contains an electron-transporting material and an electron-donating material (donor material), as described later. Composite materials can also be used.

[0110] The light-emitting device shown in Figure 1C has a hole transport layer 1112a, and a hole transport layer 1112a1 and a hole In terms of having a laminated structure with transport layer 1112a2, the third layer 1123 and hole injection layer 1111b The fourth layer 1124 is located between the light-emitting layer 1113b and the electron transport layer 1114b. It differs from the light-emitting device shown in Figure 1B in that it has a light-emitting layer 1113c between the layers.

[0111] The hole transport layers 1112a1 and 1112a2 transport holes to the light-emitting layer 1113a. This is the layer to send the signal.

[0112] The hole transport layer 1112a1 preferably contains a third compound.

[0113] The third compound is a hole-transporting material. As a hole-transporting material, it is used in the second compound. A hole-transporting material that can transport holes can be used.

[0114] The HOMO level of the third compound is preferably less than or equal to the HOMO level of the second compound. The difference between the HOMO level of the third compound and the HOMO level of the second compound is 0.2 eV. It is preferable that it be within a certain range.

[0115] It is preferable that the second and third compounds are the same, as this allows for smoother hole injection. It seems so.

[0116] The hole transport layer 1112a1 has the same configuration as the hole transport layer 1112a in Figure 1B. It is possible.

[0117] The hole transport layer 1112a2 preferably has a fourth compound. It is preferable that a2 functions as an electron blocking layer.

[0118] The fourth compound is a hole-transporting material. As a hole-transporting material, it is similar to the material used in the second compound. A hole-transporting material that can transport holes can be used.

[0119] The HOMO level of the fourth compound is preferably lower than that of the third compound. The difference between the HOMO level of the fourth compound and the HOMO level of the third compound must be within 0.2 eV. It is preferable that this be the case.

[0120] The second, third, and fourth compounds each have a carbazole skeleton and a gibberellin core. At least one of the following: nzofuran skeleton, dibenzothiophene skeleton, and anthracene skeleton It is preferable that it has

[0121] The second, third, and fourth compounds share the same hole transport skeleton (especially dibenzo). Having a furan skeleton is preferable because it facilitates hole injection.

[0122] Holes used in hole injection layer 1111a, hole transport layer 1112a1, and hole transport layer 1112a2 Because the transportable material has the above relationship, hole injection into each layer is performed smoothly, and the drive This prevents voltage increases and a state of insufficient holes in the light-emitting layer 1113a.

[0123] The fourth layer 1124 preferably has an electron-transporting material. This suppresses the interaction between the third layer 1123 and the hole injection layer 1111b, allowing electrons to move smoothly. It can be handed over to Z.

[0124] The LUMO level of the electron-transporting material in the fourth layer 1124 is the same as that of the hole injection layer 1111b. The LUMO level of the electron-accepting material and the LUM of the second material contained in the third layer 1123. It is preferable that it be between the O level. The electron transport material L used in the fourth layer 1124 The specific energy level of the UMO level is preferably -5.0 eV or higher. -3.0 eV or less is more preferable. As an electron transport material used in the fourth layer 1124 Phthalocyanine (abbreviated as H2Pc) and copper phthalocyanine (abbreviated as CuPc) are examples of phthalocyanines. Examples include cyanine-based materials or metal complexes having a metal-oxygen bond and an aromatic ligand.

[0125] The light-emitting device shown in Figure 1C comprises a light-emitting unit having a light-emitting layer 1113a and a light-emitting layer 111 It has two light-emitting units: one having 3b and a light-emitting layer 1113c. For example, the light-emitting layer 1113a emits blue fluorescence, and the light-emitting layer 1113b emits green phosphorescence. By configuring the photolayer 1113c to emit red phosphorescence, the entire light-emitting device emits white light. A light-emitting device can be obtained.

[0126] The light-emitting device shown in Figure 1D has the same configuration as the light-emitting device shown in Figure 1A, plus a functional layer 110. A light-emitting layer 1113c and a functional layer 1105d are located between 5c and the second electrode 1103.

[0127] A light-emitting device is not limited to having two light-emitting units. The light-emitting device shown in Figure 1D is A light-emitting unit including a light-emitting layer 1113a, a light-emitting unit including a light-emitting layer 1113b, and light emission This is an example having a light-emitting unit including layer 1113c and three light-emitting units. For example, In Figure 1D, the light-emitting layer 1113a is configured to emit a first blue light, and the light-emitting layer 1113 b is configured to emit green, yellow, or yellow-green light and red light, and the light-emitting layer 1113c By configuring it to emit a second blue light, the entire light-emitting device emits white light. It becomes possible to obtain a vice.

[0128] The functional layer 1105c comprises an electron transport layer, an electron injection layer, a charge generation layer, a hole injection layer, and a hole transport layer. It has at least one layer. The functional layer 1105c has a charge generation region.

[0129] The functional layer 1105d may, for example, have an electron transport layer and an electron injection layer.

[0130] [Light emission models in light-emitting devices] A light emission model in a light-emitting device according to one aspect of the present invention will be described.

[0131] Here, the hole transport layer 1112a, the light-emitting layer 1113a, and the first layer 112 shown in Figure 1B are shown. Using 1, we will explain the light emission model of the light-emitting device. The light-emitting device is limited to the configuration shown in Figure 1B. This does not apply to other configurations, and the light emission model can be applied to other configurations as well.

[0132] When the light-emitting layer 1113a becomes electron-rich, light is emitted in a localized area within the light-emitting layer 1113a. A region is formed. In other words, the width of the light-emitting region within the light-emitting layer 1113a is narrow. Therefore, in a localized region of the light-emitting layer 1113a, electron-hole recombination occurs intensively. This leads to accelerated degradation. Also, the electricity that could not be recombined in the light-emitting layer 1113a The lifespan or luminous efficiency may decrease as the child passes through the light-emitting layer 1113a. .

[0133] On the other hand, in a light-emitting device according to one aspect of the present invention, the electron transportability in the first layer 1121 is reduced. By doing so, the width of the light-emitting region in the light-emitting layer 1113a can be widened. By widening the region, the electron-hole recombination region in the light-emitting layer 1113a is created. This allows for the distribution of light. Therefore, it is possible to provide light-emitting devices with a long lifespan and good luminous efficiency. It can be provided.

[0134] A light-emitting device according to one aspect of the present invention is obtained by a driving test under conditions of constant current density. In the degradation curve of luminance, there may be a maximum value. That is, in one aspect of the present invention Optical devices may exhibit a behavior in which their brightness increases over time. This behavior is, This can offset the rapid degradation that occurs during the initial stages of operation (so-called initial degradation). Therefore, light emission By configuring the device to exhibit this behavior, the initial degradation of the light-emitting device is reduced, This significantly extends the operating life.

[0135] Furthermore, when the derivative of the degradation curve with a maximum value is taken, there is a region where the derivative value is zero. Therefore, a light-emitting device in which a portion of the derivative of the degradation curve is zero is provided according to one embodiment of the present invention. This can be rephrased as an optical device.

[0136] In one aspect of the present invention, the light-emitting device is such that, in the initial stage of operation, the light-emitting region extends to the first layer 1121 side. In this case, the light-emitting device according to one aspect of the present invention may have holes in the initial stages of operation. Due to the small injection barrier and the relatively low electron transportability of the first layer 1121, A light-emitting region (i.e., a recombination region) may be formed throughout the entire light-emitting layer 1113a.

[0137] Furthermore, the HOMO level of the first organic compound contained in the first layer 1121 is -6.0 eV or higher. Because the level is relatively high, some of the holes reach the first layer 1121, and even in the first layer 1121... Recombination may occur. This phenomenon occurs when the difference in the HOMO levels between the host material (or assist material) included in the light-emitting layer 1113a and the first organic compound is within 0.2 eV. This may also occur.

[0138] In the light-emitting device of one aspect of the present invention, as the driving time elapses, the carrier balance changes, recombination in the first layer 1121 becomes less likely to occur, and the energy of the recombined carriers can effectively contribute to light emission. Therefore, the luminance can increase compared to the initial stage of driving. This increase in luminance cancels out the rapid luminance decrease that appears at the initial stage of driving of the light-emitting device, so-called initial deterioration, and a light-emitting device with small initial deterioration and a long driving life can be provided. In this specification and the like, the above light-emitting device is sometimes referred to as a Recombination- Site Tailoring Injection structure (ReSTI structure). This may be the case.

[0139] In the light-emitting device of one aspect of the present invention, it is preferable that the first layer 1121 has portions with different mixing ratios (concentrations) of the first organic compound and the first substance in the thickness direction. Specifically, it is preferable that the first layer 1121 has portions with different mixing ratios (concentrations) of an electron-transporting material and an organometallic complex of an alkali metal or an alkaline earth metal.

[0140] The concentration of the first substance in the first layer 1121 can be estimated from the detection amounts of atoms and molecules obtained by time-of-flight secondary ion mass spectrometry (To F-SIMS: Time-of-flight secondary ion mass spectrometry). In portions composed of the same two types of materials with different mixing ratios, by ToF-SIMS analysis The magnitude of the detected values ​​corresponds to the relative abundance of the atoms or molecules of interest. Therefore, by comparing the detection amounts of electron transport materials and organometallic complexes, the large mixing ratio can be determined. It is possible to make a rough estimate.

[0141] The content of the first substance in the first layer 1121 is higher than that on the first electrode 1101 side. It is preferable that the concentration of the first substance is lower on the electrode 1103 side. In other words, the concentration of the first substance is lower on the second electrode The first layer 1121 rises from the electrode 1103 side toward the first electrode 1101 side. It is preferable that the first layer 1121 has a concentration of the first organic compound The region on the light-emitting layer 1113a side has a lower concentration of the first organic compound than the higher region. In other words, Then, the first layer 1121 is closer to the light-emitting layer 1113a than the region where the concentration of the first substance is lower. It has a region where the concentration of the first substance is high.

[0142] In the first layer 1121, there is a region where the concentration of the first organic compound is high (where the concentration of the first substance is low). The electron mobility in the (i) region is 1 × 1 when the square root of the electric field strength [V / cm] is 600. 0 -7 cm 2 / Vs or more 5×10 -5 cm 2 It is preferable that it is less than or equal to / Vs.

[0143] For example, the content (concentration) of the first substance in the first layer 1121 is shown in Figures 2A to 2D. This configuration is possible. Note that Figures 2A and 2B show a clear boundary within the first layer 1121. Figure 2C and Figure 2D show the case where there is no boundary, and Figure 2D shows the case where there is a clear boundary within the first layer 1121. They are doing it.

[0144] When there is no distinct boundary within the first layer 1121, the concentrations of the first organic compound and the first substance change continuously, respectively. FIGS. 2A and 2B show examples where the concentration of the first substance changes continuously. Also, when there is a distinct boundary within the first layer 1121, the concentrations of the first organic compound and the first substance change stepwise, respectively. FIGS. 2C and 2D show examples where the concentration of the first substance changes stepwise. Note that when the concentrations of the first organic compound and the first substance change stepwise, it is suggested that the first layer 1121 is composed of a plurality of layers. For example, FIG. 2C represents the case where the first layer 1121 has a two-layer stacked structure, and FIG. 2D represents the case where the first layer 1121 has a three-layer stacked structure. In FIGS. 2C and 2D, the dashed lines represent the regions of the boundaries between the plurality of layers.

[0145] When the second layer 1122 contains the first substance, as described above, it is preferable that the concentration of the first substance is lower in the second layer than in the first layer.

[0146] For example, the content (concentration) of the first substance in the first layer 1121 and the second layer 1122 can be configured as shown in FIGS. 2E and 2F.

[0147] For example, the concentration of the first substance changes stepwise as shown in FIGS. 2E and 2F. FIG. 2E represents the case where the first layer 1121 has a single-layer structure, and FIG. 2F represents the case where the first layer 1121 has a two-layer stacked structure.

[0148] The change in carrier balance in the light-emitting device according to one aspect of the present invention is considered to be brought about by the change in the electron mobility of the first layer 1121 ( and the second layer 1122).

[0149] In one aspect of the present invention, a light-emitting device exists in which a concentration difference of the first substance exists within the first layer 1121. The first layer 1121 is located between the region where the concentration of the first substance is low and the light-emitting layer 1113a. It has a region where the concentration of the first substance is high. That is, a region where the concentration of the first substance is low. The configuration is such that the region is located on the side of the second electrode 1103 rather than the region where the value is high.

[0150] Alternatively, a light-emitting device according to one aspect of the present invention comprises a first layer 1121 and a second layer 1122, A difference in the concentration of the first substance exists. The light-emitting device consists of a second layer 1122 and a light-emitting layer 111 Between 3a, there is a first layer 1121 in which the concentration of the first substance is higher than that of the second layer 1122. In other words, the region with a low concentration of the first substance is located closer to the second electrode 1103 than the region with a high concentration. It has a configuration that allows it to be placed.

[0151] A light-emitting device according to one embodiment of the present invention, having the above configuration, has a very long lifespan. In particular, If the initial brightness is set to 100%, the time it takes for the brightness to reach 95% (also called LT95) is... It can be made extremely long.

[0152] [Materials for light-emitting devices] The following details the materials that can be used in light-emitting devices. 05a (hole injection layer 1111a, hole transport layer 1112a), first layer 1121, second layer The materials preferred for use in layers 1122, the third layer 1123, and the fourth layer 1124 are As described above, the following materials may also be used.

[0153] <Electrode> Materials used to form a pair of electrodes in a light-emitting device include metals, alloys, electrically conductive compounds, and These mixtures can be used as appropriate. Specifically, In-Sn oxide (IT Also known as O), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, In -W-Zn oxide is one example. Other examples include aluminum (Al), titanium (Ti), and chromium oxide. Cr (Magnesium), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum Butene (Mo), Tantalum (Ta), Tungsten (W), Palladium (Pd), Gold (A) metals such as u), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), And alloys containing these in appropriate combinations can also be used. Other examples not listed above include... Elements belonging to Group 1 or Group 2 of the periodic table (for example, lithium (Li), cesium ( Cs), calcium (Ca), strontium (Sr), europium (Eu), i Rare earth metals such as terbium (Yb) and alloys containing them in appropriate combinations, graphite You can use things like n.

[0154] In one aspect of the present invention, a microcavity structure is preferably applied to the light-emitting device. Therefore, one of the pair of electrodes in the light-emitting device is transparent to visible light. It is preferable that the other side has a reflective electrode (semitransparent / semireflective electrode), and the other side is visible It is preferable to have electrodes that are reflective to light (reflective electrodes). By having a microcavity structure, the light emitted from the light-emitting layer is made to resonate between the two electrodes. It is possible to intensify the light emitted from the light-emitting device.

[0155] Semitransparent and semi-reflective electrodes are electrodes that transmit visible light (also called transparent electrodes). This allows for a layered structure of a reflective electrode and a reflective electrode.

[0156] The visible light transmittance of transparent electrodes shall be 40% or higher. The visible light reflectance of semi-transparent / semi-reflective electrodes. The visible light of the reflective electrode shall be 10% to 95%, preferably 30% to 80%. The reflectance shall be 40% or more and 100% or less, preferably 70% or more and 100% or less.

[0157] The resistivity of the first electrode 1101 and the second electrode 1103 is 1 × 10⁻⁶, respectively. -2 Ωcm or more The bottom is preferable.

[0158] The first electrode 1101 and the second electrode 1103 were fabricated using sputtering or vacuum deposition methods. It can be used.

[0159] <Hole injection layer and hole transport layer> The hole injection layer has the function of facilitating hole injection into the EL layer. For example, the hole injection layer is It has the function of injecting holes injected from the anode into a hole transport layer (or light-emitting layer, etc.). This can be done. For example, the hole injection layer generates holes and transports those holes to the hole transport layer (or It can have the function of injecting into a light layer, etc.

[0160] A material with high hole injection potential (hole injection material) can be used for the hole injection layer.

[0161] The hole injection layer contains a composite material including a material with high hole transport properties (hole transport material) and an electron-accepting material. A composite material can also be used. In this case, electron-accepting material allows electrons to be transferred from the hole-transporting material. The holes are extracted and holes are generated in the hole injection layer, and these holes are injected into the light-emitting layer via the hole transport layer. The hole injection layer is made of a composite material containing a hole transport material and an electron acceptor material. It may be formed in layers, and hole-transporting material and electron-accepting material may be laminated in separate layers to form the structure. It is permissible.

[0162] The hole transport layer is a layer that transports holes to the light-emitting layer.

[0163] A hole-transporting material can be used in the hole transport layer. The material is preferably the same as or close to the HOMO level of the hole injection layer. stomach.

[0164] Examples of hole-injectable materials include molybdenum oxide, vanadium oxide, ruthenium oxide, and Transition metal oxides such as sten oxide and manganese oxide, phthalophosphates such as H2Pc and CuPC Cyanine-based compounds and the like can be used.

[0165] As a hole-injectable material, 4,4',4''-tris(N,N-diphenylamino)tri Phenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenylamine) [phenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4' -Bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated) Name: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'- Phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-Tris[N-(4-diphenylaminophenyl)-N-phenylamino]be Nzen (abbreviation: DPA3B), 3-[N-(9-phenylcarbazole-3-yl)-N -phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-phenylamino] Su[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenyl Lucarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-fu Phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzP) Aromatic amine compounds such as CN1) can be used.

[0166] Examples of hole-injectable materials include poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4 -Vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4- (4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)meth [Crylamide] (abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl) Use -N,N'-bis(phenyl)benzidine (abbreviation: Poly-TPD), etc. This can be done. Alternatively, poly(3,4-ethylenedioxythiophene) / poly(styrene sulfur Poly(styrene sulfonic acid) (abbreviation: PEDOT / PSS), polyaniline / poly(styrene sulfonic acid) Polymer compounds to which acids such as PAni / PSS have been added can also be used.

[0167] As for the electron-accepting material used in the hole injection layer, the material that can be used in the first compound is Similar materials can be used.

[0168] The electron-accepting materials used in the hole injection layer belong to groups 4 through 8 of the periodic table. Metal oxides can also be used. Specifically, molybdenum oxide, vanadium oxide, Niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, lenite oxide Molybdenum is one example. In particular, molybdenum oxide is stable in the atmosphere and has low hygroscopicity. It's preferable because it's easy to handle.

[0169] As for the hole transport material used in the hole injection layer and hole transport layer, 1 × 10 -6 cm 2 / Vs A material having the above hole mobility is preferred. Furthermore, a material with higher hole transport than electron transport is also preferred. If available, other materials can also be used.

[0170] As a hole transport material that can be used in the hole injection layer and hole transport layer, the second compound Examples of hole-transporting materials that can be used include the hole injection layer and the hole transport layer. Other hole-transporting materials that can be used are listed below (some of which overlap with those listed above).

[0171] As hole transport materials, π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives) Thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton) Materials such as [specific items] are preferred.

[0172] Examples of carbazole derivatives (compounds having a carbazole skeleton) include bicarbazole derivatives. Aerosols (e.g., 3,3'-bicarbazole derivatives), aromatic amines having a carbazolyl group These are some examples.

[0173] Specifically, examples of bicarbazole derivatives (e.g., 3,3'-bicarbazole derivatives) include: This is 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9 '-Bis(1,1'-biphenyl-4-yl)-3,3'-bi-9H-carbazole,9 ,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole , 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl) )-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-na Phthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCC) Examples include P).

[0174] Aromatic amines having a carbazolyl group include, specifically, PCBA1BP, N-(4 -biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl ru-9H-carbazole-3-amine (abbreviation: PCBiF), PCBBiF, PCBBi 1BP, PCBANB, PCBNBB, 4-phenyldiphenyl-(9-phenyl-9H -Carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenyl)amine Nilcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviated) Name: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9- Phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3) B) 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol) [Lu-3-yl]phenyl]fluoren-2-amine (abbreviation: PCBAF), PCBASF ,PCzPCA1,PCzPCA2,PCzPCN1,3-[N-(4-diphenylamine [Nophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA) 1) 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]- 9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenyl Nylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviated) Name: PCzTPN2), 2-[N-(9-phenylcarbazole-3-yl)-N-phenylcarbazole-3-yl) [Nylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N-[4-(9H -Carbazole-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation) :YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N, N'-Diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F) ), 4,4',4''-Tris(carbazole-9-yl)triphenylamine (abbreviation: Examples include TCTA.

[0175] In addition to the above, carbazole derivatives include PCzN2, 3-[4-(9-phenant [Ryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3-[ 4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCP) N), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N -Carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenyl) Nyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N -carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl Examples include -9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), etc. It can be done.

[0176] Thiophene derivatives (compounds having a thiophene skeleton) and furan derivatives (compounds having a furan skeleton) Specifically, the compound that does this is 4,4',4''-(benzene-1,3,5-tri Il)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl- 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophen (Abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene-9) -yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) Which compounds have a thiophene skeleton, 4,4',4''-(benzene-1,3,5-tri Il)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-furan) Phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: m Examples include mDBFFLBi-II, etc.

[0177] Specifically, aromatic amines include 4,4'-bis[N-(1-naphthyl)-N-fe [Nylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methyl) (diphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (Abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl) )-N-phenylamino]biphenyl (abbreviation: BSPB), BPAFLP, mBPAFL P,N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl -2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluorene-2-yl) Mino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N- (9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenyl Amine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenyl Luamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N- (4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluor Len (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N- Phenylaminotriphenylamine (abbreviation: 1'-TNATA), TDATA, mM TDATA, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine Examples include MIN (abbreviated as DTDPPA), DPAB, DNTPD, and DPA3B.

[0178] Examples of hole-transporting materials include PVK, PVTPA, PTPDMA, and Poly-TPD. Polymer compounds can also be used.

[0179] Hole transport materials are not limited to the above, but can be one or more combinations of various known materials. It can also be used in hole injection layers and hole transport layers.

[0180] <Luminous layer> The luminescent layer is a layer containing a luminescent substance. The luminescent layer may have one or more types of luminescent substances. This is possible. The luminescent materials include blue, purple, bluish-purple, green, yellowish-green, yellow, orange, and red. Substances that exhibit emission colors such as the above are used as appropriate. In addition, substances that emit near-infrared light are used as emission materials. You can also use this.

[0181] The luminescent layer consists of one or more organic compounds (host material) in addition to the luminescent substance (guest material). It may contain (materials, assisting materials, etc.). One or more types of organic compounds include: Using one or both of the hole-transporting material and the electron-transporting material described in the embodiment. This is possible. Furthermore, bipolar materials may be used as one or more types of organic compounds. stomach.

[0182] There are no particular limitations on the luminescent material that can be used in the luminescent layer, and the singlet excitation energy is A light-emitting material that converts emission to the visible light region or the near-infrared light region, or triplet excitation energy A light-emitting material can be used that converts light emission into visible light or near-infrared light emission.

[0183] Examples of light-emitting materials that convert singlet excitation energy into light include fluorescent materials. Examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, Fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives Conductors, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidines Examples include derivatives, phenanthrene derivatives, naphthalene derivatives, etc. In particular, pyrene derivatives It is preferable because it has a high luminescence quantum yield. A specific example of a pyrene derivative is N,N'-bis( 3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9- [Iyl]phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9- [Iyl]phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N' -Bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (Abbreviation: 1,6FrAPrn), N,N'-bis(dibenzothiophen-2-yl)-N ,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N' -(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d] [Furan)-6-amine](abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6 -Diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-ami [n] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bi Su[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine]( Examples include the abbreviation 1,6BnfAPrn-03). In particular, these 1,6FLPAP Pyrenees such as rn, 1,6mMemFLPAPrn, 1,6BnfAPrn-03 Condensed aromatic diamine compounds, such as mine compounds, exhibit high hole-trapping properties and luminescence. It is preferable because it has excellent rates and reliability.

[0184] In addition, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2, 2'-Bipyridine (abbreviation: PAP2BPy), 5,6-Bis[4'-(10-phenyl- 9-Anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2B) Py), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N' -Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-Cal Bazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (Abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-di Phenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-di Phenyl-N-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazo 4-(10-phenyl-9-anthryl)-4 (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4 '-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PC) BAPA), 4-[4-(10-phenyl-9-antryl)phenyl]-4'-(9- Phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPBA) ), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP) ), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1- Phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine](abbreviated) Name: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-A Nantrillyl]phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N -[4-(9,10-diphenyl-2-antryl)phenyl]-N,N',N'-triphenyl Phenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), 3,10-bis[N -(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2 ,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)- 02) 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]na Futo[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf( IV)-02), etc., can be used.

[0185] Examples of light-emitting materials that convert triplet excitation energy into light include phosphorescent materials (phosphorescent). (Photoluminescent materials) and materials that exhibit thermally activated delayed fluorescence (Thermally Activated Delayed Fluorescence (TADF) material It can be listed.

[0186] Examples of phosphorescent materials include 4H-triazole skeletons, 1H-triazole skeletons, and Organometallic compounds having a midazole, pyrimidine, pyrazine, or pyridine skeleton. Complexes (especially iridium complexes), using phenylpyridine derivatives having electron-withdrawing groups as ligands. Examples include organometallic complexes (especially iridium complexes), platinum complexes, and rare earth metal complexes.

[0187] It exhibits a blue or green color, and the peak wavelength of its emission spectrum is between 450 nm and 570 nm. Examples of phosphorescent materials include the following:

[0188] For example, Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl )-4H-1,2,4-triazole-3-yl-κN2]phenyl-κC}iridium (III) (Abbreviation: [Ir(mpptz-dmp)3]), Tris(5-methyl-3,4) -Diphenyl-4H-1,2,4-Triazolat) Iridium(III) (Abbreviation: [Ir (Mptz)3]), Tris[4-(3-biphenyl)-5-isopropyl-3-phenyl Iridium(III) (abbreviation: [Ir(iPrp) Tris[3-(5-biphenyl)-5-isopropyl-4-phenyl]), Tris[3-(5-biphenyl)-5-isopropyl-4-phenyl Iridium(III) (abbreviation: Ir(iPr5b)) Organometallic complexes having a 4H-triazole skeleton, such as tris[3-(3)(3)), [Tyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato] Iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), Tris(1-methyl) -5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III (Abbreviation: [Ir(Prptz1-Me)3]) has a 1H-triazole skeleton The organometallic complex, fac-tris[1-(2,6-diisopropylphenyl)-2-fe [Nyl-1H-imidazole] Iridium(III) (abbreviation: [Ir(iPrpmi)3] ), Tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f] [Iridium(III) (abbreviation: Ir(dmpimpt-Me)3)] Organometallic complexes having an imidazole skeleton such as ) and bis[2-(4',6'-difluoro (lophenyl)pyridinate-N,C 2’ Iridium(III) tetrakis(1-pyrazoli) (Abbreviation: Fir6), Bis[2-(4',6'-difluorophenyl)pyryl Dinato-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), bis {2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C} 2’} Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), Bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ ]iridium( III) Substances that have an electron-withdrawing group, such as acetylacetonate (abbreviation: Fir(acac)) Examples include organometallic complexes using phenylpyridine derivatives as ligands.

[0189] It exhibits a green or yellow color, and the peak wavelength of its emission spectrum is between 495 nm and 590 nm. Examples of phosphorescent materials include the following:

[0190] For example, Tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation) :[Ir(mppm)3]), Tris(4-t-butyl-6-phenylpyrimidinato) Lydium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonate) Iridium(III) (abbreviation: [Ir(m ppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4) -Phenylpyrimidina) Iridium(III) (Abbreviation: [Ir(tBuppm)2(a (cac)), (acetylacetonato)bis[6-(2-norbornyl)-4-phenyl [Pyrimidinato] Iridium(III) (Abbreviation: [Ir(nbppm)2(acac)]) (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenyl [Lupyrimidinat] Iridium(III) (Abbreviation: [Ir(mpmppm)2(acac) ]), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethyl [phenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation) :[Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4 ,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2( Organometallic iridium complexes having a pyrimidine skeleton such as (acac), (acetylated iridium complexes Setonato)bis(3,5-dimethyl-2-phenylpyradinate)iridium(III) Abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5 -Isopropyl-3-methyl-2-phenylpyradinato) Iridium(III) (abbreviation: Organometallic compounds with a pyrazine skeleton, such as [Ir(mppr-iPr)2(acac)]). Iridium complex, Tris(2-phenylpyridinato-N,C) 2’ Iridium (III) (Abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C) 2’ ) Iridi Um(III)acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), Su(benzo[h]quinolinate)iridium(III)acetylacetonate (abbreviation: [I r(bzq)2(acac)]), Tris(benzo[h]quinolinate) Iridium(II I) (abbreviation: [Ir(bzq)3]), Tris(2-phenylquinolinato-N,C) 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinazole) N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(a cac)]), [2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]bis[ 2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir( ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC] [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC] Organometallic iridium complex having a pyridine skeleton, bis(2,4-diphenyl-1,3-o Xazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir( dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl] Pyridinate-N,C 2’ Iridium(III) acetylacetonate (abbreviation: [Ir( p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolat-N,C 2 ’ Iridium(III) acetylacetonate (abbreviation: [Ir(bt)2(acac) In addition to organometallic complexes such as ]), tris(acetylacetonato)(monophenanthroline) Rare earth golds such as terbium(III) (abbreviation: [Tb(acac)3(Phen)]) Examples include genus complexes.

[0191] It exhibits a yellow or red color, and the peak wavelength of its emission spectrum is between 570 nm and 750 nm. Examples of phosphorescent materials include the following:

[0192] For example, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrim [Dinato] Iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), Su[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)yl Dium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di (Naphthalene-1-yl)pyrimidinato](Dipivaloylmethanato) Iridium (III) (Abbreviation: [Ir(d1npm)2(dpm)]), Tris(4-t-butyl-6-phenyl) Like iridium(III) (abbreviation: [Ir(tBuppm)3]) nilpyrimidinato Organometallic complex having a pyrimidine skeleton, (acetylacetonato)bis(2,3,5-) Iridium(III) (Abbreviation: [Ir(tppr)2(acac) )]), Bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridi Um(III) (abbreviation: [Ir(tppr)2(dpm)]), bis{4,6-dimethyl} -2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyradinyl-κN]f {enyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ 2 O,O') Iriji Um(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6 -dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-didimethylphenyl)-3-(3,5-didimethylphenyl)-2-[5-(4-cyano-2,6-2-[5-(4-cyano-2,6-dimethylphenyl)-2-(3,5-didimethylphenyl)- Methylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetra Methyl-3,5-heptanedionato-κ 2 O,O') Iridium(III) (Abbreviation: [I r(dmdppr-dmCP)2(dpm)]), (acetylacetonate)bis[2-methyl Tyl-3-phenylquinoxalinato-N,C 2’ Iridium(III) (abbreviation: [Ir (mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinone Kisarinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(dpq)2(acac )]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxa [Linato] Iridium (III) (abbreviation: [Ir(Fdpq)2(acac)]), Bis{ 4,6-dimethyl-2-[5-(5-cyano-2-methylphenyl)-3-(3,5-di Methylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetra Methyl-3,5-heptanedionato-κ2O,O') Iridium(III) (abbreviation: [I Organometallic compounds with a pyrazine skeleton, such as r(dmdppr-m5CP)2(dpm)]). Complexes, or Tris(1-phenylisoquinolinato-N,C) 2’ ) Iridium (III) (abbreviated) Name: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) Iridi Um(III)acetylacetonate (abbreviation: [Ir(piq)2(acac)]), S[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-phenyl Tangionato-κ 2 Organic compounds with a pyridine skeleton, such as O,O') iridium(III). Metal complex, 2,3,7,8,12,13,17,18-octaethyl-21H,23H- Platinum complexes such as porphyrin platinum(II) (abbreviation: [PtOEP]), tris(1,3) -Diphenyl-1,3-propanedionato)(monophenanthroline)europium(I II) (Abbreviation: [Eu(DBM)3(Phen)]), Tris[1-(2-Tenoyl)- 3,3,3-trifluoroacetonate](monophenanthroline)europium(III Examples include rare earth metal complexes such as [Eu(TTA)3(Phen)] (abbreviated as [Eu(TTA)3(Phen)]).

[0193] Organic compounds used in the light-emitting layer (host material, assist material, etc.) include those with the energy of the light-emitting substance. Select one or more materials that have an energy gap larger than the G-gap. It can be used.

[0194] Organic compounds used in combination with fluorescent materials include those with singlet excited states. It is preferable to use an organic compound with a large position and a small energy level in the triplet excited state. .

[0195] Although some of the examples above overlap, a preferred combination is with luminescent materials (fluorescent materials, phosphorescent materials). From the perspective of combinations, specific examples of organic compounds are shown below.

[0196] Organic compounds that can be used in combination with fluorescent materials include anthracene derivatives. Body, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, diben Examples include condensed polycyclic aromatic compounds such as zo[g,p]chrysene derivatives.

[0197] Specific examples of organic compounds used in combination with fluorescent substances include 9-phenyl-3-[ 4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviation: PC) zPA), 3,6-diphenyl-9-[4-(10-phenyl-9-antryl)phenyl [L]-9H-carbazole (abbreviation: DPCzPA), PCPN, 9,10-diphenyl Ntracene (abbreviation: DPAnth), N,N-diphenyl-9-[4-(10-phenyl -9-Anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA) ), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA) , YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl- 9-Anthryl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PC) APBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9 H-carbazole-3-amine (abbreviation: 2PCAPA), 6,12-dimethoxy-5,1 1-Diphenylchrysene, N,N,N',N',N'',N'',N''',N'''- Octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation) :DBC1), CzPA, 7-[4-(10-phenyl-9-antryl)phenyl]- 7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9, 10-Diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]f Ran (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H- Fluoren-9-yl)biphenyl-4'-yl}anthracene (abbreviation: FLPPA), 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'-biant Lil (abbreviation: BANT), 9,9'-(Stilben-3,3'-Zil) Jifenantre n (abbreviation: DPNS), 9,9'-(stilben-4,4'-diyl)diphenanthrene (Abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (Abbreviation: TPB3) , 5,12-diphenyltetracene, 5,12-bis(biphenyl-2-yl)tetracene , 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated) Examples include αN-βNPAnth.

[0198] Organic compounds used in combination with phosphorescent materials include those with the triplet excitation energy of the phosphorescent material. - (The energy difference between the ground state and the triplet excited state) is greater than the triplet excitation energy. You should select an organic compound.

[0199] Multiple organic compounds (e.g., a first host material and a second host material) are used to form an excited complex. When using a light-emitting material (or assist material, etc.) in combination with a light-emitting material, these It is preferable to use a mixture of multiple organic compounds with phosphorescent materials (especially organometallic complexes). .

[0200] By using this configuration, the energy transfer from the excited complex to the luminescent material, called Ex, is achieved. Using TET (Exciplex-Triplet Energy Transfer) This allows for efficient emission. Furthermore, as a combination of multiple organic compounds, Compounds that readily form complexes are preferred, and compounds that readily accept holes (hole transport materials) are also desirable. It is particularly preferable to combine it with a compound that readily accepts electrons (electron transport material). An excitation complex that exhibits emission that overlaps with the wavelength of the lowest energy absorption band of the luminescent material. By selecting combinations that form such structures, energy transfer becomes smoother and more efficient. Light emission can be obtained. Furthermore, specific examples of hole transport materials and electron transport materials are provided. The materials shown in this embodiment can be used. This configuration allows for high performance of the light-emitting device. It can achieve high efficiency, low voltage operation, and long lifespan simultaneously.

[0201] As for combinations of materials that form excited complexes, the HOMO level of the hole transport material is the electron transport level. It is preferable that the value is above the HOMO level of the hole transport material. It is preferable that the low-altitude orbital level is greater than or equal to the LUMO level of the electron-transporting material. The MO level and HOMO level are measured by cyclic voltammetry (CV). This can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material being used.

[0202] The formation of excited complexes is observed, for example, in the emission spectra of hole transport materials and electron transport materials. The emission spectra of the individual material and the mixed film made by mixing these materials were compared, and the emission spectrum of the mixed film was determined. The culprit shifts to a longer wavelength than the emission spectrum of each material (or a new peak is added on the longer wavelength side). This can be confirmed by observing phenomena (with a hole). Alternatively, hole transport materials Transient photoluminescence (PL) of materials, transient PL of electron transport materials, and mixing of these materials The transient PL of the combined mixed film was compared, and the transient PL lifetime of the mixed film was found to be longer than the transient PL lifetime of each individual material. We observed differences in transient responses, such as the presence of long-lived components or a larger proportion of delayed components. This can be confirmed by doing so. Also, the transient PL mentioned above is transient electroluminescent It can also be read as EL. That is, transient EL of hole transport materials, electron We compared the transient electroluminescence (EL) of transportable materials and the transient EL of mixed films of these materials, and observed the differences in transient response. The formation of excited complexes can also be confirmed by doing so.

[0203] Organic compounds that can be used in combination with phosphorescent substances include aromatic amines. Compounds having a fragrant amine skeleton), carbazole derivatives, dibenzothiophene derivatives ( Offen derivatives), dibenzofuran derivatives (furan derivatives), zinc and aluminum-based gold Group complexes, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, Noxaline derivatives, dibenzoquinoxaline derivatives, pyrimidine derivatives, triazine derivatives Examples include pyridine derivatives, bipyridine derivatives, and phenanthroline derivatives.

[0204] Aromatic amines, carbazole derivatives, and dibenzothiops are organic compounds with high hole transport capabilities. Specific examples of benzofuran derivatives and dibenzofuran derivatives include the hole transport materials shown above. The same examples as above can be cited.

[0205] Examples of zinc and aluminum-based metal complexes, which are organic compounds with high electron transport capabilities, include Tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), Tris(4- Methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10 -Hydroxybenzo[h]quinolinate)beryllium(II) (abbreviation: BeBq2), bis (2-methyl-8-quinolinolate)(4-phenylphenolate)aluminum(III) (Abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (Abbreviation: Znq), etc. Examples include metal complexes having a noline skeleton or a benzoquinoline skeleton.

[0206] In addition, bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviation: Zn) PBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) (abbreviation: Zn) Metal complexes having an oxazole skeleton such as BTZ, metal complexes having a thiazole skeleton, etc. It can be used in any way.

[0207] Organic compounds with high electron transport properties include oxadiazole derivatives, triazole derivatives, and ve Nzoimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenan A specific example of a trolin derivative is 2-(4-biphenylyl)-5-(4-tert- Tylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5- (p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benz (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole- 2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenyl (Lu)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole TAZ (abbreviation), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl (p-EtTAZ)-5-(4-biphenylyl)-1,2,4-triazole , 2-{4-[9,10-di(naphthalene-2-yl)-2-anthryl]phenyl}- 1-Phenyl-1H-benzimidazole (abbreviation: ZADN), 2,2',2''-(1 ,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimidazole) (abbreviated) Name: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl Ru-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5- Methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs), bathophenant Lorin (abbreviation: Bphen), vasocuproine (abbreviation: BCP), 2,9-bis(naph Talene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBp) hen), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h] Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene) [-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDB) TBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3 -Il]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-( 3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]k Noxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophene-4- [Iyl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) , and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quino Examples include xalin (abbreviated as 6mDBTPDBq-II).

[0208] Organic compounds with high electron transport capabilities, heterocyclic compounds having a diazine skeleton, triazine skeleton Specific examples of heterocyclic compounds having a pyridine skeleton include 4,6 -Bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPn) P2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation) :4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-I) [Phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 2-{4-[3-(N-Phenyl]pyrimidine [phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl} -4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3 -(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl Nyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[ 3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3 -yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2 -[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobyl] (9H-fluorene)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn) ), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl ]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTz n), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phen [L]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPT) (zn-02), 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridin (Abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]be Examples include Nzen (abbreviated as TmPyPB).

[0209] Organic compounds with high electron transport capabilities include poly(2,5-pyridinediyl) (abbreviation: PPy ), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3 ,5-diyl)](abbreviation: PF-Py), poly[(9,9-dioctylfluorene-2, 7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)(abbreviation: PF-B) Polymer compounds such as Py can also be used.

[0210] TADF materials are materials with S1 levels (singlet excited state energy levels) and T1 levels (triplet excited state energy levels). The difference from the energy level of the initial state is small, and the triplet excitation energy is obtained by reverse intersystem crossing. It is a material that has the function of converting energy to singlet excitation energy. Therefore, the triplet excitation energy is converted to the singlet excitation energy by a small amount of thermal energy. Upconversion (reverse intersystem crossing) is possible, and singlet excited states can be efficiently generated. Yes, it is possible. Furthermore, the triplet excitation energy can be converted into luminescence. (Thermal-activated delayed fluorescence) The conditions under which this can be efficiently obtained are that the energy difference between the S1 and T1 levels is 0 eV or greater. The voltage is 2eV or less, preferably 0eV or more and 0.1eV or less. Delayed fluorescence in DF materials is a type of fluorescence that exhibits a spectrum similar to normal fluorescence but with a significantly longer lifetime. It refers to a very long period of luminescence. Its lifespan is 10 -6 10 seconds or more, preferably 10 -3 It is more than a second.

[0211] Excited complexes, which form excited states using two different substances, have an extremely small difference between the S1 and T1 levels. TADF materials capable of converting triplet excitation energy to singlet excitation energy It functions as such.

[0212] The phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) serves as an indicator of the T1 level. This can be used. As for the TADF material, the short-wavelength tail of its fluorescence spectrum is tangent. Draw a line, and set the energy at the wavelength of that extrapolation line as the S1 level, and the short wavelength side of the phosphorescence spectrum When a tangent line is drawn at the tail and the energy of the wavelength of the extrapolation line is taken as the T1 level, then the S1 It is preferable that the difference between and T1 is 0.3 eV or less, and even more preferable that it is 0.2 eV or less. preferable.

[0213] TADF materials may be used as guest materials or as host materials.

[0214] Examples of TADF materials include fullerenes and their derivatives, and acridines such as proflavin. Examples include derivatives and eosin. Also, magnesium (Mg), zinc (Zn), cadmium Um (Cd), tin (Sn), platinum (Pt), indium (In), or palladium Examples of metal-containing porphyrins include those containing (Pd), etc. For example, protoporphyrin-tin fluoride complex (abbreviation: SnF2 (Proto IX)) Mesoporphyrin-tin fluoride complex (abbreviation: SnF2 (Meso IX)), hematopo Rufirin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), copropolph Fluorine tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III- 4Me)), Octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)) , Ethioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), Octae Examples include tilporphyrin-platinum chloride complex (abbreviated as PtCl2OEP).

[0215] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[ 2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-T RZ), PCCzPTzn, 2-[4-(10H-phenoxazine-10-yl)pheni [Lu]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[ 4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5 -Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9- Dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviation: AC) RXTN), bis[4-(9,9-dimethyl-9,10-dihydroacrylidine)phenyl ]Sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[ Acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc. Heterocyclic compounds having electron-excess heteroaromatic rings and π-electron-deficient heteroaromatic rings can be used. The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring. Therefore, it is preferable because it has high electron transport and hole transport properties. Alternatively, an aromatic ring to which an electron-withdrawing group such as a cyano group is attached may be used. Instead of electron-deficient heteroaromatic rings, π-electron-deficient skeletons can be used. Similarly, π-electron Instead of a polycarbonate complex aromatic ring, a polycarbonate skeleton with an excess of π electrons can be used.

[0216] Among skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine) The skeletons (pyrazine skeleton, pyridazine skeleton) and triazine skeleton are stable and reliable. Therefore, it is preferable. In particular, the benzoflopyrimidine skeleton, the benzothienopyrimidine skeleton, and benzo The flopyrazine skeleton and benzothienopyrazine skeleton have high electron-accepting properties and good reliability. preferable.

[0217] Among skeletons having a π-electron-rich heteroaromatic ring, the acridine skeleton, the phenoxazine skeleton, and fu The phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are stable and reliable. It is preferable to have at least one of the said skeletons for better performance. In particular, dibenzofuran Skeleton, dibenzothiophene skeleton, indole skeleton, carbazole skeleton, indolocarbazo 3-(9-phenyl-9H-carbazole-3-yl) A -9H-carbazole skeleton is preferred.

[0218] Furthermore, in substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, Both the donor properties of the electron-excess type heteroaromatic ring and the acceptor properties of the π-electron-deficient type heteroaromatic ring are strong. This is particularly preferable because it reduces the energy difference between the singlet excited state and the triplet excited state.

[0219] As π-electron-rich skeletons, aromatic amine skeletons, phenazine skeletons, and the like can be used. Examples of π-electron-deficient skeletons include xanthene skeletons, thioxanthene dioxide skeletons, and oxadioxide skeletons. Azole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, phenylbone Boron-containing skeletons such as or and volanthrene, and nitriles such as benzonitrile or cyanobenzene. Aromatic rings or heteroaromatic rings having a cyano group or a benzophenone, carbonyl skeletons, Phosphine oxide skeletons, sulfone skeletons, etc., can be used.

[0220] Furthermore, when using TADF material as a luminescent substance, it should be used in combination with other organic compounds. It is also possible to combine it with the aforementioned host material (hole transport material, electron transport material). It can be made to work. When using TADF material, the S1 level of the host material is the TADF material It is preferable that the T1 level of the host material is higher than the S1 level of the TADF material. A higher rank is preferable.

[0221] Alternatively, a TADF material may be used as the host material and a fluorescent material as the guest material. When ADF material is used as the host material, the triplet excitation energy generated in TADF material However, through reverse intersystem crossing, it is converted into singlet excitation energy, and further into the luminescent material. By moving it, the luminescence efficiency of the light-emitting device can be increased. At this time, TADF material The material functions as an energy donor, and the light-emitting material functions as an energy acceptor. Therefore, using TADF material as the host material means that fluorescent material is used as the guest material. It is very effective when using quality. Also, in order to obtain high luminescence efficiency in this case, T The S1 level of the ADF material is preferably higher than that of the fluorescent material. The T1 level of the DF material is preferably higher than the S1 level of the fluorescent material. Therefore, The T1 level of the TADF material is preferably higher than that of the fluorescent material.

[0222] Furthermore, T exhibits emission that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material. It is preferable to use ADF material. This allows the fluorescent material to be converted from TADF material. This is preferable because it allows for smoother transfer of excitation energy and efficient emission.

[0223] Furthermore, singlet excitation energy is efficiently generated from triplet excitation energy through reverse intersystem crossing. For this to occur, it is preferable that carrier recombination occurs in the TADF material. The triplet excitation energy generated by the DF material is transferred to the triplet excitation energy of the fluorescent material. It is preferable not to do so. To that end, the fluorescent material has a luminescent phosphodiolus ( It is preferable to have a protecting group around the skeleton that causes light emission. The protecting group is a π bond. Substituents that do not have a substituent are preferred, saturated hydrocarbons are preferred, specifically those having 3 to 10 carbon atoms. The alkyl group below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, carbon Examples include trialkylsilyl groups with a number between 3 and 10, and it is even preferable if there are multiple protecting groups. Substituents that do not have a π bond have poor carrier transport function, therefore carrier transport and The distance between the TADF material and the fluorescent material's luminescent phosphate is minimized without affecting carrier recombination. It can keep the distance away. Here, a luminescent group is the substance that causes light emission in a fluorescent substance. This refers to an atomic group (skeleton). The luminescent group preferably has a skeleton with π bonds and contains an aromatic ring. It is preferable that it has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of compound aromatic rings include the phenanthrene skeleton, stilbene skeleton, acridone skeleton, and pheno Examples include xazine skeletons and phenothiazine skeletons. In particular, naphthalene skeletons and anthracene skeletons. Skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetracene skeleton, pyrene skeleton It has a perylene skeleton, coumarin skeleton, quinacridone skeleton, and naphthobisbenzofuran skeleton. Fluorescent materials are preferred because they have a high fluorescence quantum yield.

[0224] <Electron injection layer and electron transport layer> The electron injection layer has the function of facilitating the injection of electrons into the EL layer. For example, the electron injection layer is It has the function of injecting electrons injected from the cathode into the electron transport layer (or light-emitting layer, etc.). This is possible. For example, the electron injection layer generates electrons and then transports those electrons to the electron transport layer (or generator). It can have the function of injecting into a light layer, etc.

[0225] Materials with high electron-injection potential (electron-injection materials) can be used in the electron injection layer.

[0226] The electron injection layer contains materials with high electron transport properties (electron transport materials) and electron-donating materials (donor materials). Composite materials containing (materials) can also be used. In this case, electron-donating materials are used to transport electrons. Holes are extracted from the electron-transfer material, generating electrons in the electron injection layer, which then travel through the electron transport layer to the light-emitting layer. Electrons are injected into it. The electron injection layer is a composite material containing an electron transport material and an electron donating material. It may be formed as a single layer of composite materials, with the electron transport material and the electron donating material being separate. It may also be formed by laminating layers of the material.

[0227] The electron transport layer is a layer that transports electrons to the light-emitting layer.

[0228] An electron transport material can be used for the electron transport layer.

[0229] Examples of electron-injectable materials include materials similar to those used for the second substance. ru.

[0230] As electron-donating materials used in electron injection layers, materials that exhibit electron-donating properties relative to electron-transporting materials. The same material can be used for the second substance. Specifically, a material similar to the material that can be used for the second substance. The amount is listed.

[0231] The electron transport material used in the electron injection layer and electron transport layer is 1 × 10 -6 cm 2 / Vs or higher A material with electron mobility is preferred. In addition, any material with higher electron transport capabilities than hole transport is preferred. Other materials can also be used.

[0232] As the electron transport material, an electron transport material that can be used in the first organic compound is used. It is possible.

[0233] The light-emitting device according to one aspect of the present invention may be fabricated using a vacuum process such as vapor deposition or spin coating. Solution processes such as vapor deposition and inkjet methods can be used. These include sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum vapor deposition. Physical vapor deposition (PVD) methods such as deposition and chemical vapor deposition (CVD) methods can be used. In particular, the functional layers included in the EL layer (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer) For layering, etc., methods include vapor deposition (vacuum deposition, etc.) and coating (dip coating, etc.). (Inkjet method, bar coating method, spin coating method, spray coating method, etc.), printing method (inkjet) Methods include screen printing, offset printing, and flexographic printing. It can be formed by methods such as gravure printing and microcontact printing.

[0234] The materials used for the functional layers constituting the light-emitting device are not limited to the materials described above. For example, As materials for the functional layer, polymer compounds (oligomers, dendrimers, polymers, etc.), intermediate Sub-compounds (compounds in the intermediate region between low molecular weight and high molecular weight: molecular weight between 400 and 4000), inorganic Compounds (such as quantum dot materials) may also be used. Note that the quantum dot material may be colloidal. Quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dot materials Materials such as small dots can be used.

[0235] As described above, the light-emitting device of this embodiment uses a first material (metal, metal salt, metal oxide). A first layer having a (or organometallic salt) and a third layer having a second material (electron-injectable material) Between the first layer and the second layer, there is a second layer in which the concentration of the first substance is lower than that of the first layer. This configuration enhances the electron injection from the third layer to the second layer, and further to the first layer. The driving voltage of the light-emitting device can be reduced. This improves the reliability of the light-emitting device. It can improve.

[0236] This embodiment can be appropriately combined with other embodiments. Furthermore, this specification Furthermore, if multiple configuration examples are shown within a single embodiment, the configuration examples may be combined as appropriate. It is possible to do so.

[0237] (Embodiment 2) In this embodiment, a light-emitting device according to one aspect of the present invention will be described with reference to Figures 3 to 5.

[0238] [Example of Light-Emitting Device Configuration 1] Figure 3A shows a top view of the light-emitting device, and Figures 3B and 3C show the area between X1 and Y1 in Figure 3A. Figures 3A and 3C show a cross-sectional view between X2 and Y2. The light-emitting device shown in Figures 3A to 3C is, for example, a lighting device. It can be used for bottom emission, top emission, and dual emission. Any type of emission is acceptable.

[0239] The light-emitting device shown in Figure 3B consists of substrate 490a, substrate 490b, conductive layer 406, conductive layer 416, Insulating layer 405, organic EL device 450 (first electrode 401, EL layer 402, and second The organic EL device 450 has an electrode 403) and an adhesive layer 407. Embodiment 1 It is preferable to apply the configuration of a light-emitting device according to one embodiment of the present invention, as shown.

[0240] The organic EL device 450 has a first electrode 401 on the substrate 490a and on the first electrode 401 It has an EL layer 402 and a second electrode 403 on the EL layer 402. Substrate 490a, bonded The organic EL device 450 is sealed by layer 407 and substrate 490b.

[0241] The first electrode 401, the conductive layer 406, and the edges of the conductive layer 416 are covered with an insulating layer 405. The conductive layer 406 is electrically connected to the first electrode 401, and the conductive layer 416 is electrically connected to the second electrode 403. Electrically connected. The conductive layer 406, covered by the insulating layer 405 via the first electrode 401, It functions as auxiliary wiring and is electrically connected to the first electrode 401. Organic EL device 450 Having auxiliary wiring electrically connected to the electrodes suppresses voltage drops caused by the resistance of the electrodes. Therefore, it is preferable. The conductive layer 406 may be provided on the first electrode 401. Furthermore, even if there is auxiliary wiring on the insulating layer 405 that is electrically connected to the second electrode 403, good.

[0242] Substrates 490a and 490b are made of glass, quartz, ceramic, and sapphire, respectively. Organic resins and the like can be used. The substrates 490a and 490b have flexibility. Using this material can increase the flexibility of the display device.

[0243] The light-emitting surface of the light-emitting device features a light extraction structure to improve light extraction efficiency and a design to suppress dust adhesion. It features an antistatic coating to control static electricity, a water-repellent coating to prevent dirt from adhering, and suppresses the occurrence of scratches during use. A hard coat film, shock-absorbing layer, etc., may be provided.

[0244] Examples of insulating materials that can be used for the insulating layer 405 include acrylic resin and epoxy. Resins such as resins, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, Examples include inorganic insulating materials such as aluminum oxide.

[0245] The adhesive layer 407 can be a photocuring adhesive such as an ultraviolet curing type, a reaction curing adhesive, or a thermocuring type Various types of curing adhesives, such as adhesives and anaerobic adhesives, can be used. For example, epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, Imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin Examples include EVA (ethylene vinyl acetate) resin, etc. In particular, epoxy resins and other permeable materials. Materials with low moisture content are preferred. A two-component resin may also be used. Adhesive sheets are also available. You may also use the following:

[0246] The light-emitting device shown in Figure 3C consists of a barrier layer 490c, a conductive layer 406, a conductive layer 416, and an insulating layer 40 5. Having an organic EL device 450, an adhesive layer 407, a barrier layer 423, and a substrate 490b. ru.

[0247] The barrier layer 490c shown in Figure 3C consists of the substrate 420, the adhesive layer 422, and a highly barrier-free insulating layer. It has a layer 424.

[0248] In the light-emitting device shown in Figure 3C, between the highly barrier insulating layer 424 and the barrier layer 423, The EL device 450 is located there. Therefore, compared to substrates 420 and 490b Even when using resin films with relatively low water resistance, impurities such as water can enter the organic EL device. This can suppress the reduction in installation life.

[0249] Substrates 420 and 490b are each made of, for example, polyethylene terephthalate (P Polyester resins such as polyethylene naphthalate (PEN), polyacrylonite Polyyl resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate Polyethylene (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon) (Aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, poly Amidoimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, Polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cell Rose nanofibers and the like can be used. The substrates 420 and 490b are flexible. Glass of a certain thickness may be used to achieve the desired properties.

[0250] As the insulating layer 424 with high barrier properties, it is preferable to use an inorganic insulating film. Examples include silicon nitride film, silicon oxide nitride film, silicon oxide film, silicon nitride oxide film. Recon film, aluminum oxide film, aluminum nitride film, etc., can be used. Hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, t Lanthanum film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film Other materials may be used. Furthermore, two or more of the above-mentioned insulating films may be stacked and used.

[0251] The barrier layer 423 preferably has at least one inorganic film. Layer 423 can be configured with a single-layer inorganic film structure or a multilayer structure of inorganic and organic films. The inorganic insulating film is preferred as the inorganic film. The laminated structure is, for example, acid Silicon nitride film, silicon oxide film, organic film, silicon oxide film, silicon nitride film Examples include a configuration in which the following are formed in sequence. The protective layer is a laminated structure of an inorganic film and an organic film. This prevents impurities (typically hydrogen, water, etc.) that could enter the OLED device 450. It can be effectively suppressed.

[0252] The highly barrier insulating layer 424 and the organic EL device 450 are on a flexible substrate 420. It can be formed directly on top. In this case, the adhesive layer 422 is unnecessary. Also, the insulating layer 4 24 and the organic EL device 450 are formed on a rigid substrate via a release layer, and then on the substrate 42 It can be transposed to 0. For example, by applying heat, force, laser light, etc. to the delamination layer Then, after peeling off the insulating layer 424 and the organic EL device 450 from the rigid substrate, the adhesive layer 422 The substrate 420 may be bonded using the release layer and then transferred to the substrate 420. Examples include a laminated structure of inorganic films containing a tungsten film and a silicon oxide film, and polyimide. Organic resin films such as the above can be used. When a rigid substrate is used, compared to resin substrates, etc. Therefore, since the insulating layer 424 can be formed by applying high temperatures, the insulating layer 424 can be made dense and extremely This allows for the creation of an insulating film with high barrier properties.

[0253] [Example of Light-Emitting Device Configuration 2] Figure 4A shows a cross-sectional view of the light-emitting device. The light-emitting device shown in Figure 4A consists of a transistor and a light-emitting device. This is an active matrix type light-emitting device in which the chair and other components are electrically connected.

[0254] The light-emitting device shown in Figure 4A consists of a substrate 201, a transistor 210, a light-emitting device 203R, and Optical device 203G, light-emitting device 203B, color filter 206R, color filter It includes components such as 206G, a color filter 206B, and a substrate 205.

[0255] In Figure 4A, a transistor 210 is provided on the substrate 201, and an insulating layer is placed on the transistor 210. An edge layer 202 is provided, and light-emitting devices 203R, 203G, and 203B are placed on the insulating layer 202. It is provided.

[0256] Transistor 210 and light-emitting devices 203R, 203G, and 203B are located on substrate 201 It is sealed in a space 207 surrounded by the substrate 205 and the adhesive layer 208. 07 can be applied, for example, to a reduced-pressure atmosphere, an inert atmosphere, or a resin-filled configuration. .

[0257] The light-emitting device shown in Figure 4A has one pixel that is a red sub-pixel (R), a green sub-pixel (G), and It has a configuration that includes a blue sub-pixel (B).

[0258] A light-emitting device according to one aspect of the present invention has a plurality of pixels arranged in a matrix. Each element has one or more subpixels. Each subpixel has one light-emitting device. For example, For example, a pixel may have three subpixels (using three colors: R, G, and B, or yellow (Y), sheath). (For example, a three-color system consisting of C, M, and R, G) or a configuration having four subpixels (R, G You can apply four colors (B, W, or R, G, B, Y).

[0259] Figure 4B shows the light-emitting devices 203R, 203G, and 203B. The detailed configuration is shown below. The light-emitting devices 203R, 203G, and 203B share a common EL layer 21 It has 3, and depending on the emission color of each light-emitting device, the optical distance between the electrodes of each light-emitting device Each light-emitting device has a microcavity structure that is adjusted. Therefore, it is preferable to apply the configuration of a light-emitting device according to one aspect of the present invention.

[0260] The first electrode 211 functions as a reflective electrode, and the second electrode 215 is a semi-transmissive / semi-reflective electrode. It functions as such.

[0261] The light-emitting device 203R has a first electrode 211 and a second electrode 211 so that the intensity of the red light is increased. The distance between the electrode 215 and the device is adjusted to an optical distance of 220R. Similarly, the light-emitting device S203G uses the first electrode 211 and the second electrode 215 to increase the intensity of the green light. The distance between them is adjusted to an optical distance of 220G, and the light-emitting device 203B emits blue light. To increase the intensity, the distance between the first electrode 211 and the second electrode 215 is an optical distance of 220B. It has been adjusted to be so.

[0262] As shown in Figure 4B, in the light-emitting device 203R, the conductive layer 212R is the first electrode 211 A conductive layer 212G is formed on the first electrode 211 in the light-emitting device 203G. By doing so, optical adjustment can be performed. Furthermore, in the light-emitting device 203B, A conductive layer with a different thickness from the electrolytic layer 212R and the conductive layer 212G is formed on the first electrode 211. The optical distance 220B may be adjusted. Note that, as shown in Figure 4A, the first electrode 21 1. The edges of the conductive layer 212R and the conductive layer 212G are covered with the insulating layer 204.

[0263] The light-emitting device shown in Figure 4A emits light from the light-emitting device onto the substrate 205, forming various colors. It is a top-emission type light-emitting device that emits light through a color filter. A filter can allow a specific wavelength range of visible light to pass through and block a specific wavelength range. .

[0264] In the red subpixel (R), light emitted from the light-emitting device 203R is reflected in the red color filter 2 It is ejected via 06R. As shown in Figure 4A, it is located in a position that overlaps with the light-emitting device 203R. By providing a color filter 206R that allows only the red wavelength range to pass through, the light-emitting device Red light can be obtained from 203R.

[0265] Similarly, in the green subpixel (G), light emission from the light-emitting device 203G is emitted from the green color chromatic aberration. Emitted through filter 206G, in the blue subpixel (B), from light-emitting device 203B The light emitted is transmitted through the blue color filter 206B.

[0266] Furthermore, at the edges of one type of color filter, there is a black matrix 209 (which can also be called a black layer). A black matrix may also be provided. Furthermore, a color filter for each color and a black matrix may be provided. 209 may be covered with an overcoat layer that transmits visible light.

[0267] The light-emitting device shown in Figure 4C has one pixel that contains a red subpixel (R), a green subpixel (G), and a blue subpixel. The configuration has a color subpixel (B) and a white subpixel (W). In Figure 4C, the white sub Light from the light-emitting device 203W of the pixel (W) is emitted without passing through a color filter. It is ejected to the outside of the location.

[0268] Furthermore, the optical relationship between the first electrode 211 and the second electrode 215 in the light-emitting device 203W The distance may be the same as that of any of the light-emitting devices 203R, 203G, or 203B. It can be different from either of them.

[0269] For example, if the light emitted from the 203W light-emitting device is white light with a low color temperature, blue If you want to increase the intensity of light of a specific wavelength, as shown in Figure 4C, use the light-emitting device 203W. It is preferable to make the optical distance equal to the optical distance 220B in the light-emitting device 203B. This allows the light obtained from the 203W light-emitting device to be brought closer to the desired color temperature of white light. It can be attached.

[0270] Figure 4A shows a top-emission type light-emitting device, but as shown in Figure 4D, A structure that extracts light from the substrate 201 side on which the zista 210 is formed (bottom emission type) The light-emitting device described above is also one aspect of the present invention.

[0271] In a bottom-emission type light-emitting device, color filters for each color are connected to the substrate 201 and the light-emitting device. It is preferable to place it between the chair. In Figure 4D, the transistor 210 is on the substrate 201. A color layer is formed on the transistor 210, and an insulating layer 202a is formed on the insulating layer 202a. Filters 206R, 206G, and 206B are formed, and color filters 206R, 206G, 2 An insulating layer 202b is formed on 06B, and light-emitting devices 203R and 203 are placed on the insulating layer 202b. An example of G, forming 203B is shown.

[0272] In the case of a top-emission type light-emitting device, the substrate 201 may be a light-shielding substrate or a light-transmitting substrate. A substrate can be used, and a translucent substrate can be used as substrate 205.

[0273] In the case of a bottom-emission type light-emitting device, the substrate 205 may be a light-shielding substrate or a light-transmitting substrate. A substrate can be used, and a translucent substrate can be used as substrate 201.

[0274] [Example of Light-Emitting Device Configuration 3] A light-emitting device according to one aspect of the present invention is of the passive matrix type or the active matrix type. This is possible. An active matrix type light-emitting device will be explained using Figure 5.

[0275] Figure 5A shows a top view of the light-emitting device. Figure 5B shows a cross-sectional view between the dashed line A and A' shown in Figure 5A. This indicates.

[0276] The active matrix type light-emitting device shown in Figures 5A and 5B consists of a pixel section 302 and a circuit section 30 3. It has circuit section 304a and circuit section 304b.

[0277] Circuit section 303, circuit section 304a, and circuit section 304b each comprise a scanning line drive circuit (G It can function as a source driver or a signal line driving circuit (source driver). Alternatively, an external gate driver or source driver and the pixel unit 302 are electrically connected. It may also be a circuit to be connected to.

[0278] On the first circuit board 301, routing wiring 307 is provided. The routing wiring 307 is external It is electrically connected to the input terminal FPC308. The FPC308 is connected to the circuit section 303. Circuit section 304a and circuit section 304b receive external signals (for example, video signals, clock signals). It transmits signals (start signals, reset signals, etc.) and electric potential. The FPC308 also has a preamplifier. A circuit board (PWB) may be attached. The configuration shown in Figures 5A and 5B is It can also be described as a light-emitting module having an optical device (or light-emitting device) and an FPC (flexible printed circuit board).

[0279] The pixel section 302 includes an organic EL device 317, a transistor 311, and a transistor 31 The organic EL device 317 has multiple pixels having 2. The organic EL device 317 has the same as shown in Embodiment 1. It is preferable to apply the configuration of the light-emitting device according to one aspect of the invention. Transistor 312 is It is electrically connected to the first electrode 313 of the organic EL device 317. Transistor 311 functions as a switching transistor. Transistor 312 is an electric It functions as a transistor for current control. The number of transistors in each pixel is particularly important. There are no limitations, and they can be established as needed.

[0280] The circuit section 303 includes multiple transistors, such as transistor 309 and transistor 310. It has a transistor. Circuit section 303 has a unipolar (either N-type or P-type only) transistor. The circuit may be formed by including a transistor, or by including an N-type transistor and a P-type transistor. It may be formed using CMOS circuits. Alternatively, it may have an external drive circuit.

[0281] The structure of the transistor in the light-emitting device of this embodiment is not particularly limited. For example, Uses na-type transistors, staggered transistors, inverse staggered transistors, etc. It is possible to do this. Also, either top-gate or bottom-gate transistor structure Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed. That's good too.

[0282] The crystallinity of semiconductor materials used in transistors is not particularly limited; amorphous semiconductors, Semiconductors with crystalline properties (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or those with a crystalline region in part) Any semiconductor (having a region) may be used. If a semiconductor with crystalline properties is used, This is preferable because it suppresses the degradation of the DISTA characteristics.

[0283] The semiconductor layer of a transistor preferably contains a metal oxide (also called an oxide semiconductor). i. Alternatively, the semiconductor layer of the transistor may have silicon. This includes amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.). ) are some examples.

[0284] The semiconductor layer is, for example, made of indium and M (where M is gallium, aluminum, silicon, and chlorine). Iron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, gel Manium, Zirconium, Molybdenum, Lanthanum, Cerium, Neodymium, Hafnium, Ta (One or more selected from tungsten, magnesium, and zinc) It is preferable that it has the following. In particular, M is aluminum, gallium, yttrium, and s It is preferable that it be one or more types selected from the group.

[0285] In particular, the semiconductor layer contains indium (In), gallium (Ga), and zinc (Zn). It is preferable to use an oxide (also written as IGZO).

[0286] When the semiconductor layer is In-M-Zn oxide, the In-M-Zn oxide is used to form the film. For sputtering targets, it is preferable that the atomic ratio of In is greater than or equal to the atomic ratio of M. The atomic ratio of metal elements in such a sputtering target is In:M:Zn= 1:1:1, In:M:Zn=1:1:1.2, In:M:Zn=2:1:3, In:M :Zn=3:1:2, In:M:Zn=4:2:3, In:M:Zn=4:2:4.1, In:M:Zn=5:1:6, In:M:Zn=5:1:7, In:M:Zn=5:1: 8. Examples include In:M:Zn=6:1:6 and In:M:Zn=5:2:5.

[0287] The transistors in circuit section 303, circuit section 304a, and circuit section 304b, and the pixel section 302 The transistors in the circuit may have the same structure or different structures. The structures of the multiple transistors in circuit section 303, circuit section 304a, and circuit section 304b are all the same. They may be the same, or there may be two or more types. Similarly, the multiple traces that the pixel unit 302 has The structure of the inverter may be the same for all of them, or there may be two or more different types.

[0288] The end of the first electrode 313 is covered with an insulating layer 314. Organic compounds such as negative-type photosensitive resins and positive-type photosensitive resins (acrylic resins), and oxidation Inorganic compounds such as silicon, silicon oxide nitride, and silicon nitride can be used. It is preferable that the upper or lower end of layer 314 has a curved surface with curvature. This allows for good coverage of the film formed on the upper layer of the insulating layer 314.

[0289] An EL layer 315 is provided on the first electrode 313, and a second electrode 316 is provided on the EL layer 315. A EL layer 315 is provided. The EL layer consists of an emissive layer, a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. It has an interlayer, a charge generation layer, etc.

[0290] Multiple transistors and multiple organic EL devices 317 are mounted on a first substrate 301, a second substrate The first substrate 301 and the second substrate are sealed by the plate 306 and the sealing material 305. The space 318 enclosed by plate 306 and sealing material 305 is an inert gas (such as nitrogen or argon). ) or organic matter (including sealant 305) may be filled.

[0291] Epoxy resin or glass frit can be used for the sealant 305. For the 305 material, it is preferable to use a material that does not permeate moisture or oxygen as much as possible. When glass frit is used as the adhesive material, the first substrate 301 and The substrate 306 of the second substrate is preferably a glass substrate.

[0292] Figures 5C and 5D show examples of transistors that can be used in light-emitting devices.

[0293] The transistor 320 shown in Figure 5C has a conductive layer 321 that functions as a gate, and a gate insulating layer The insulating layer 328, the channel-forming region 327i, and the pair of low-resistance regions 327n function as insulating layers, channel-forming regions 327i, and a pair of low-resistance regions 327n. A semiconductor layer 327 having a conductive layer 322a connected to one of a pair of low-resistance regions 327n, A conductive layer 322b connects to the other of a pair of low-resistance regions 327n, functioning as a gate insulating layer. An insulating layer 325, a conductive layer 323 that functions as a gate, and an insulating layer covering the conductive layer 323. It has a layer 324. The insulating layer 328 is between the conductive layer 321 and the channel forming region 327i. The insulating layer 325 is located between the conductive layer 323 and the channel-forming region 327i. It is preferable that the transistor 320 is covered by an insulating layer 326. 26 may be included as a component of transistor 320.

[0294] The conductive layer 322a and the conductive layer 322b are separated by openings provided in the insulating layer 324. It is connected to the low-resistance region 327n. Of the conductive layer 322a and conductive layer 322b, one is One acts as the source, and the other as the drain.

[0295] The insulating layer 325 is provided overlapping with at least the channel formation region 327i of the semiconductor layer 327. The insulating layer 325 may cover the top and side surfaces of a pair of low-resistance regions 327n.

[0296] The transistor 330 shown in Figure 5D has a conductive layer 331 that functions as a gate, and a gate insulating layer An insulating layer 338 that functions as a source and a drain, and a conductive layer 332a and a conductive layer that functions as a source and a drain. The electrical layer 332b, the semiconductor layer 337, the insulating layer 335 which functions as a gate insulating layer, and It has a conductive layer 333 that functions as a core. The insulating layer 338 is made up of conductive layer 331 and semiconductor layer 3 It is located between 37. The insulating layer 335 is located between the conductive layer 333 and the semiconductor layer 337. The transistor 330 is preferably covered by an insulating layer 334. 334 may be included as a component of transistor 330.

[0297] Transistors 320 and 330 have two semiconductor layers in which the channel is formed. A configuration is applied in which the gates are sandwiched together. Two gates are connected and the same signal is passed to them. The transistor may be driven by supplying a signal. Alternatively, one of the two gates By applying a potential to control the threshold voltage to one side and a potential to drive the other side, The threshold voltage of the transistor may be controlled.

[0298] At least one layer of the insulating layer covering the transistor is made of a material that does not easily diffuse impurities such as water and hydrogen. It is preferable to use a material. This allows the insulating layer to function as a barrier layer. This configuration effectively prevents impurities from diffusing into the transistor from the outside. This allows for effective suppression and improves the reliability of the light-emitting device.

[0299] insulating layer 325, insulating layer 326, insulating layer 328, insulating layer 334, insulating layer 335, and insulating layer For 338, it is preferable to use an inorganic insulating film. As for the inorganic insulating film, For example, silicon nitride film, silicon oxide nitride film, silicon oxide film, silicon nitride oxide film, Aluminum oxide films, aluminum nitride films, etc. can be used. yttrium film, zirconium oxide film, gallium oxide film, tantalum oxide film, Using magnesium oxide film, lanthanum oxide film, cerium oxide film, neodymium oxide film, etc. Alternatively, two or more of the above-mentioned insulating films may be stacked and used.

[0300] Furthermore, aluminum is one of the materials that can be used for the various conductive layers that make up the light-emitting device. Titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tan Examples include tungsten, a metal, or an alloy primarily composed of these materials. Furthermore, films containing these materials can be used as a single layer or as a multilayer structure. For example For example, a single-layer structure of an aluminum film containing silicon, or a layer of aluminum films on a titanium film. Two-layer structure, two-layer structure with an aluminum film laminated on a tungsten film, copper-magnesium- A two-layer structure in which a copper film is laminated on an aluminum alloy film, and a two-layer structure in which a copper film is laminated on a titanium film. , a two-layer structure in which a copper film is laminated on a tungsten film, a titanium film or a titanium nitride film, and on the An aluminum film or copper film is layered on top of that, and then a titanium film or titanium nitride film is placed on top of that. A three-layer structure forming a film, a molybdenum film or molybdenum nitride film, and an aluminum layer on top of it. A layer of aluminum or copper film is laminated, and then a molybdenum film or molybdenum nitride film is formed on top of it. It has a three-layer structure, etc. Furthermore, oxides such as indium oxide, tin oxide, or zinc oxide are used. It is acceptable to use it. Furthermore, using copper containing manganese improves the controllability of the shape through etching. Therefore, it is preferable.

[0301] This embodiment can be combined with other embodiments as appropriate.

[0302] (Embodiment 3) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to the figures.

[0303] Examples of electronic devices include television equipment, computer monitors, and digital displays. Cameras, digital video cameras, digital photo frames, mobile phones (mobile phones, mobile phones) (Also called telephone equipment), portable game consoles, personal digital assistants, sound playback devices, pachinko machines, etc. Examples include large-scale game consoles, biometric authentication devices, and inspection equipment.

[0304] An electronic device according to one aspect of the present invention has a light-emitting device according to one aspect of the present invention in its display unit, therefore reliability It's expensive.

[0305] The display unit of the electronic device in this embodiment can display, for example, Full HD, 4K2K, 8K4K, It can display video with a resolution of 16K, 8K, or higher. The display screen sizes are 20 inches or larger diagonally, 30 inches or larger diagonally, and 50 inches diagonally. The diagonal size can be 60 inches or more, or 70 inches or more.

[0306] Because an electronic device according to one aspect of the present invention is flexible, it can be used on the interior or exterior walls of a house or building. Alternatively, it can be incorporated along the curved surfaces of the car's interior or exterior.

[0307] Furthermore, an electronic device according to one aspect of the present invention may have a secondary battery and use contactless power transmission. It would be preferable if it could also charge a secondary battery.

[0308] Examples of secondary batteries include lithium polymer batteries (lithium iodine) which use a gel electrolyte. Lithium-ion secondary batteries such as polymer batteries, nickel-metal hydride batteries, nickel-cadmium batteries, organic polymer batteries, etc. Examples include zinc batteries, lead-acid batteries, rechargeable air batteries, nickel-zinc batteries, and silver-zinc batteries. .

[0309] An electronic device according to one aspect of the present invention may have an antenna. The antenna receives a signal. This allows the display unit to show images or information. Furthermore, electronic devices can use antennas. If an antenna and a secondary battery are present, the antenna may be used for contactless power transmission.

[0310] The electronic device of this embodiment has sensors (force, displacement, position, velocity, acceleration, angular velocity, rotational speed, Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, electric current, voltage, power, radiation (including functions for measuring radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation) It's fine if you do that.

[0311] The electronic device of this embodiment can have various functions. For example, it can display various information (static Functions to display still images, videos, text images, etc. on the display unit, touch panel function, calendar - Functions to display the date or time, and to run various software (programs) Functions, wireless communication functions, and functions to read programs or data recorded on recording media. It may have the following:

[0312] Figure 6A shows an example of a television system. The television system 7100 is housed in a casing 7101. A display unit 7000 is incorporated. Here, the stand 7103 supports the housing 7101. This shows the configuration that was supported.

[0313] A light-emitting device according to one embodiment of the present invention can be applied to the display unit 7000. By using a light-emitting device according to one aspect of the present invention, the reliability of the television device 7100 can be improved. It is possible.

[0314] The television device 7100 shown in Figure 6A is operated using the control switches provided on the housing 7101. This can be done using a separate remote control unit 7111. Alternatively, the display unit 7000 can be used to control it. It may also be equipped with a touch sensor, and may be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 displays the information output from the remote control unit 7111. It may have an indicator. Operation keys or touch panel provided on the remote control unit 7111 This allows you to control the channel and volume, and the video displayed on the display unit 7000 It can be operated.

[0315] The television system 7100 will consist of a receiver and a modem, etc. This allows you to receive regular television broadcasts. Additionally, you can receive them via a modem using either a wired or wireless connection. By connecting to a line communication network, one-way (sender to receiver) or bidirectional communication is possible. It is also possible to communicate information in a direction (between a sender and receiver, or between receivers). ru.

[0316] Figure 6B shows an example of a notebook personal computer. The 7200 consists of a chassis 7211, a keyboard 7212, and a pointing device 7213. It has external connection ports 7214, etc. The display unit 7000 is incorporated into the housing 7211. Yes, they are.

[0317] A light-emitting device according to one embodiment of the present invention can be applied to the display unit 7000. By using a light-emitting device according to one aspect of the present invention, a notebook personal computer 7200 This can increase its reliability.

[0318] Figures 6C and 6D show examples of digital signage.

[0319] The digital signage 7300 shown in Figure 6C consists of a housing 7301, a display unit 7000, and a speaker. It has a 7303, etc. Furthermore, it has an LED lamp, an operation key (power switch, or operation It may include switches, connection terminals, various sensors, microphones, etc.

[0320] Figure 6D shows a digital signage 7400 mounted on a cylindrical column 7401. The Tal Signage 7400 has a display unit 7000 that is installed along the curved surface of the column 7401. ru.

[0321] In Figures 6C and 6D, a light-emitting device according to one embodiment of the present invention is applied to the display unit 7000. This is possible. By using a light-emitting device according to one aspect of the present invention in the display unit 7000, digital signage can be displayed. This can improve the reliability of the 7300 and 7400 models.

[0322] The larger the display area 7000, the more information can be provided at once. The wider the area (7000), the more easily it catches people's attention, which can, for example, enhance the effectiveness of advertising. Cut.

[0323] By applying a touch panel to the display unit 7000, images or videos can be displayed on the display unit 7000. It is desirable that it not only displays information but also allows users to operate it intuitively. Furthermore, route information is also available. Or, when used for purposes such as providing traffic information, intuitive operation is possible. It can improve usability.

[0324] Furthermore, as shown in Figures 6C and 6D, the digital signage 7300 or digital signage Page 7400 is an information terminal 7311 or other information terminal owned by the user, such as a smartphone. It is preferable that the terminal unit 7411 can be communicated with wireless communication. For example, the display unit 7000 The advertisement information displayed will be shown on the screen of information terminal 7311 or information terminal 7411. It can also be made to operate the information terminal 7311 or the information terminal 7411. This allows you to switch the display on the 7000 display unit.

[0325] In addition, the information terminal 7 is connected to the digital signage 7300 or digital signage 7400. Execute a game using the screen of either the 311 or the information terminal 7411 as the control device (controller). It is also possible to allow this. This allows a large number of users to participate in the game and enjoy it simultaneously. It is possible.

[0326] Figures 7A to 7F show an example of a portable information terminal having a flexible display unit 7001. By using a light-emitting device according to one aspect of the present invention in the display unit 7001, the reliability of the portable information terminal can be improved. It is possible to do so.

[0327] The display unit 7001 is manufactured using a light-emitting device according to one aspect of the present invention. For example, radius of curvature 0 A light-emitting device that can be bent between 0.01 mm and 150 mm can be applied. The unit 7001 may be equipped with a touch sensor, and by touching the display unit 7001 with a finger, etc. It is possible to operate the information terminal.

[0328] Figures 7A to 7C show an example of a foldable portable information terminal. Figure 7A shows the unfolded terminal. In Figure 7B, the state is in the process of changing from either the unfolded or folded state to the other. Figure 7C shows the folded state of the personal digital information terminal 7600. The 600 offers excellent portability when folded, and a seamless, wide surface when unfolded. The display area provides excellent overview.

[0329] The display unit 7001 is supported by three housings 7601 connected by hinges 7602. The hinge 7602 bends the two housings 7601 together, allowing the portable information terminal to be positioned. The 7600 can be reversibly transformed from an unfolded state to a folded state.

[0330] Figures 7D and 7E show an example of a foldable portable information terminal. In Figure 7D, the display unit 7 In the folded state where 001 is on the inside, Figure 7E shows the display unit 7001 on the outside. The image shows the 7650 portable information terminal in its folded state. The 7650 portable information terminal has a display unit. It has 7001 and a non-display section 7651. When the portable information terminal 7650 is not in use, the display By folding it so that part 7001 faces inward, dirt or scratches on the display part 7001 can be prevented. It can be suppressed.

[0331] Figure 7F shows an example of a wristwatch-type personal information terminal. The personal information terminal 7800 uses Band 780 1. It has a display unit 7001, input / output terminals 7802, operation buttons 7803, etc. Band 78 01 has the function of an enclosure. In addition, the portable information terminal 7800 has a flexible bag It can be equipped with the 7805 battery. The 7805 battery is, for example, the display unit 7001 and It may be placed in conjunction with band 7801.

[0332] The band 7801, the display unit 7001, and the battery 7805 are flexible. Therefore, The 7800 mobile information terminal can be easily bent into a desired shape.

[0333] The 7803 control button is used for setting the time, turning the power on and off, and turning wireless communication on and off. It has various functions such as operation, silent mode activation and deactivation, and power saving mode activation and deactivation. This can be done. For example, the operating system built into the mobile information terminal 7800 The stem allows you to freely configure the functions of the 7803 control button.

[0334] Furthermore, by touching the icon 7804 displayed on the display unit 7001 with your finger, etc., the application can be accessed. You can start the program.

[0335] Furthermore, the 7800 portable information terminal is capable of performing standardized short-range wireless communication. Yes, for example, by communicating with a wireless headset, hands-free operation is possible. You can also make phone calls.

[0336] Furthermore, the personal information terminal 7800 may also have an input / output terminal 7802. If 02 is present, data can be exchanged directly with other information terminals via a connector. Yes, it is possible. Furthermore, charging can be performed via the input / output terminal 7802. Note that this embodiment... The charging operation of the portable information terminal exemplified here is performed by contactless power transmission without using input / output terminals. That's fine.

[0337] Figure 8A shows the exterior of the automobile 9700. Figure 8B shows the driver's seat of the automobile 9700. 9700 consists of the body 9701, wheels 9702, windshield 9703, lights 9704, It has fog lamps 9705, etc. A light-emitting device according to one aspect of the present invention is a display for automobile 9700 It can be used in parts such as the display units 9710 to 9715 shown in Figure 8B. A light-emitting device according to one aspect of the present invention can be provided. Alternatively, light 9704 or fog A light-emitting device according to one embodiment of the present invention may be used for the lamp 9705.

[0338] Display units 9710 and 9711 are display devices installed on the windshield of an automobile. In one embodiment of the present invention, the light-emitting device is made of a light-transmitting conductive material for the electrodes and wiring. By doing so, it becomes possible to create a so-called see-through state where the other side is visible. If the display unit 9710 or the display unit 9711 is in a see-through state, then the operation of the automobile 9700 It does not obstruct the view at all times. Therefore, a light-emitting device according to one aspect of the present invention is used in automobiles 970 It can be installed on the windshield of a 0. Note that the transistor for driving the light-emitting device If a transistor is to be installed, an organic transistor using organic semiconductor material or an oxide semiconductor transistor may be used. It is preferable to use a transistor that is transparent to light, such as a transistor using a conductor.

[0339] The display unit 9712 is a display device provided on the pillar portion. For example, a camera provided on the vehicle body By displaying the image from the imaging device on the display unit 9712, the field of view obstructed by the pillar is compensated for. It can be completed. The display unit 9713 is a display device provided on the dashboard. For example, by displaying images from an imaging device installed on the vehicle body on the display unit 9713, This allows you to compensate for the view obstructed by the dashboard. In other words, on the outside of the car By displaying images from the installed imaging device, blind spots are compensated for, and safety is enhanced. This is possible. Furthermore, by displaying images that fill in the gaps in the unseen areas, it becomes more natural and less jarring. Safety checks can be performed without any issues.

[0340] Figure 8C also shows the interior of a car with bench seats for both the driver and passenger. The display unit 9721 is a display device provided in the door section. For example, an imaging device provided on the vehicle body By displaying the image from the means on the display unit 9721, the view obstructed by the door is compensated for. It is possible to do so. Furthermore, the display unit 9722 is a display device provided on the handle. Part 9723 is a display device located in the center of the seat surface of the bench seat. The device is installed on the seat or backrest, etc., to dissipate the heat generated by the display device. It can also be used as a seat heater.

[0341] Display unit 9714, display unit 9715, or display unit 9722 displays navigation information, speed It displays the odometer, tachometer, mileage, fuel gauge, gear status, and air conditioning settings. This allows for the provision of various information. Furthermore, the display items and layout displayed on the display unit... Settings such as output can be changed as needed to suit the user's preferences. Note that the above information is... Display units 9710 to 9713, 9721, and 9723 can also display information. Yes, it is possible. Also, display units 9710 to 9715 and 9721 to 9723 are illuminated. It can also be used as a lighting device. Furthermore, display units 9710 to 9715, display unit Units 9721 to 9723 can also be used as heating devices.

[0342] This embodiment can be combined with other embodiments as appropriate. [Examples]

[0343] In this example, a light-emitting device according to one aspect of the present invention is fabricated and the results of its evaluation are described. .

[0344] In this embodiment, as the light-emitting device, Device 1 and Device to which one aspect of the present invention is applied This section describes the results of fabricating and evaluating device S2 and comparison device 3 for comparison. Figure 9A shows the structures of Device 1, Device 2, and Comparison Device 3 used in the example. The composition is shown in Table 1. The chemical formulas of the materials used in this embodiment are shown below.

[0345] [Table 1]

[0346] [ka]

[0347] [ka]

[0348] Fabrication of light-emitting devices Device 1, Device 2, and Comparison Device 3 shown in this embodiment are as shown in Figure 9A, A first electrode 801 is formed on the substrate 800, and a hole injection layer 811a is placed on the first electrode 801. , hole transport layer 812a1, hole transport layer 812a2, light-emitting layer 813a, first layer 821, Layer 2 822, Layer 3 823, Layer 4 824, Hole injection layer 811b, Hole transport layer 81 2b, light-emitting layer 813b1, light-emitting layer 813b2, light-emitting layer 813b3, electron transport layer 814b1 The electron transport layer 814b2 and the electron injection layer 815b are sequentially stacked, and the electron injection layer 815b It has a structure in which a second electrode 803 is formed on top.

[0349] The light-emitting devices fabricated in this embodiment all include a microcable configured to enhance blue light. A biti structure was applied.

[0350] First, a first electrode 801 was formed on the substrate 800. The electrode area was 4 mm². 2 (2mm x 2 The thickness was set to mm. A glass substrate was used for substrate 800. The first electrode 801 was made of silver (Ag). And a palladium (Pd) and copper (Cu) alloy (Ag-Pd-Cu(APC)) is sputtered A film was deposited using a molding method to a thickness of 100 nm, and indium tin oxide containing silicon oxide was used. (ITSO) is deposited by sputtering to a thickness of 10 nm, It was accomplished. In this embodiment, the first electrode 801 functions as an anode.

[0351] Here, as a pretreatment, the surface of the substrate is washed with water, then fired at 200°C for 1 hour, followed by UV spectroscopy. The zoning process was performed for 370 seconds. After that, 10 -4Vacuum deposition equipment with internal pressure reduced to approximately Pa The substrate is placed in the vacuum deposition apparatus and vacuum firing is performed at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus. Afterward, I let the circuit board cool for about 30 minutes.

[0352] Next, a hole injection layer 811a was formed on the first electrode 801. The hole injection layer 811a is true Inside the empty deposition apparatus 10 -4 After reducing the pressure to Pa, N,N-bis(4-biphenyl)-6-fe Nylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and A LD-MP001Q (Analysis Workshop Co., Ltd., Material serial number: 1S20180314) and The weight ratio is 1:0.1 (=BBABnf:ALD-MP001Q), and the film thickness is 10nm. It was formed by co-deposition in such a manner. ALD-MP001Q is an electron receiver for BBABnf. It has capacity.

[0353] Next, a hole transport layer 812a1 was formed on the hole injection layer 811a. The film was formed by depositing BBABnf to a thickness of 10 nm.

[0354] Next, a hole transport layer 812a2 was formed on the hole transport layer 812a1. 2 is 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazo It was formed by depositing (abbreviated as PCzN2) to a film thickness of 10 nm.

[0355] Next, a light-emitting layer 813a was formed on the hole transport layer 812a2. The light-emitting layer 813a is a host The material used is 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthra. Using sen (abbreviated as αN-βNPAnth), 3, as guest material (fluorescent material) 10-Bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3 -b;6,7-b']Bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02 Using ), the weight ratio is 1:0.015 (=αN-βNPAnth:3,10FrA2Nbf (IV)-02] was formed by co-depositing to a film thickness of 25 nm.

[0356] Next, a first layer 821 was formed on the light-emitting layer 813a. In device 1 and device 2 The first layer 821 is 2-{4-[9,10-di(naphthalene-2-yl)-2-ant [Lyl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN) and 8- (Kinorinorato) Lithium (abbreviation: Liq) (Chemipro Chemical Co., Ltd., serial number: 18120) 1) Deposit the two materials so that the weight ratio is 1:1 (=ZADN:Liq) and the film thickness is 20 nm. The first layer 821 in comparative device 3 is composed of ZADN and Liq in a weight ratio. The material was formed by deposition with a 1:1 ratio (=ZADN:Liq) and a film thickness of 25 nm.

[0357] Next, a second layer 822 was formed on the first layer 821. Second layer 82 in device 1 2 uses ZADN, and the second layer 822 in device 2 is 2,9-bis(naphthalate) NBphe (-2-yl)-4,7-diphenyl-1,10-phenanthroline Using n), each was formed by deposition to a film thickness of 5 nm. In comparative device 3... The second layer 822 was not provided.

[0358] Next, a third layer 823 was formed on the second layer 822 (or on the first layer 821). Layer 823 was deposited using lithium oxide (Li2O) to a thickness of 0.1 nm. It was formed by [doing something].

[0359] Next, a fourth layer 824 was formed on the third layer 823. The fourth layer 824 was made of copper phthalosia. It was formed by depositing nin (CuPc) to a film thickness of 2 nm.

[0360] Next, a hole injection layer 811b was formed on the fourth layer 824. The hole injection layer 811b was 1, 3,5-tri(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II) and Molybdenum oxide and film in a weight ratio of 1:0.5 (=DBT3P-II:molybdenum oxide). It was formed by co-depositing to a thickness of 10 nm.

[0361] Next, a hole transport layer 812b was formed on the hole injection layer 811b. The hole transport layer 812b is N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazo [I-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation) It was formed by depositing PCBBiF to a film thickness of 15 nm.

[0362] Next, a light-emitting layer 813b1 was formed on the hole transport layer 812b. The light-emitting layer 813b1 is phosphate As a material, 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl] Using dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), PCBBiF is used as the base material, and bis{4,6} is used as the guest material (phosphorescent material). -dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl -κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ2O,O Iridium(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]) is used. The weight ratio is 0.6:0.4:0.06 (=2mDBTBPDBq-II:PCBBiF :[Ir(dmdppr-P)2(dibm)]), co-deposited to a film thickness of 10 nm. It was formed in this way.

[0363] Next, a light-emitting layer 813b2 was formed on the light-emitting layer 813b1. The light-emitting layer 813b2 is a host 2mDBTBPDBq-II was used as the material, and PCBBiF was used as the assist material. The guest material (phosphorescent substance) used is tris(4-t-butyl-6-phenylpyrylene pyropropyl alcohol). Using iridium(III) (abbreviation: [Ir(tBuppm)3]), by weight ratio ga 0.8:0.2:0.06(=2mDBTBPDBq-II:PCBBiF:[Ir( The film was formed by co-depositing tBuppm)3) to a thickness of 30 nm.

[0364] Next, a light-emitting layer 813b3 was formed on the light-emitting layer 813b2. The light-emitting layer 813b3 is a light-emitting layer Using the same materials and weight ratio as 813b1, a film thickness of 5 nm was formed.

[0365] Next, an electron transport layer 814b1 was formed on the light-emitting layer 813b3. The electron transport layer 814b1 is Using 2mDBTBPDBq-II, the film was deposited to a thickness of 10 nm.

[0366] Next, an electron transport layer 814b2 was formed on the electron transport layer 814b1. Layer 2 was formed by depositing NBphen to a film thickness of 15 nm.

[0367] Next, an electron injection layer 815b was formed on the electron transport layer 814b2. The electron injection layer 815b is The film was formed by depositing lithium fluoride (LiF) to a thickness of 1 nm.

[0368] Next, a second electrode 803 was formed on the electron injection layer 815b. The second electrode 803 is made of silver ( Ag (Ag) and magnesium (Mg) are used in a volume ratio of 1:0.1 (=Ag:Mg) with a film thickness of 25 After co-depositing to an nm size, indium tin oxide (ITO) is applied by sputtering. The film was formed by depositing a film with a thickness of 70 nm. In this embodiment, The second electrode 803 functions as a cathode.

[0369] Through the above process, a light-emitting device is formed on the substrate 800, with an EL layer sandwiched between a pair of electrodes. The hole injection layer, hole transport layer, light emission layer, electron transport layer, and electron transport layer described in the above process were completed. The injection layer and the first to fourth layers are functional layers constituting the EL layer in one aspect of the present invention. Furthermore, in the deposition process of the above-described manufacturing method, the resistance heating method was used for all deposition steps. .

[0370] Furthermore, the light-emitting device fabricated as described above is sealed with another substrate (not shown). Furthermore, when sealing using a different substrate (not shown), the glove box should be kept in a nitrogen atmosphere. In this process, another substrate (not shown) coated with an adhesive that hardens when exposed to ultraviolet light is placed on substrate 800. The substrate is fixed in place, and adhesive is applied to the periphery of the light-emitting device formed on the substrate 800. The material was bonded together. During sealing, 365nm ultraviolet light at 6J / cm² was applied. 2 Irradiate to solidify the adhesive, The adhesive was stabilized by heat treatment at 80°C for 1 hour.

[0371] <<Operating characteristics of light-emitting devices>> The operating characteristics of device 1, device 2, and comparison device 3 were measured. The experiment was conducted at room temperature (in an atmosphere maintained at 25°C).

[0372] Figure 10 shows the brightness-current efficiency characteristics of each light-emitting device. Figure 11 shows the current efficiency characteristics of each light-emitting device. This shows the pressure-current characteristics.

[0373] Table 2 shows 1000 cd / m². 2 The main initial characteristic values ​​of each light-emitting device in the vicinity are shown.

[0374] [Table 2]

[0375] As shown in Figures 10, 11, and Table 2, each light-emitting device exhibits high luminous efficiency. As shown in Figure 11, compared to comparison device 3, devices 1 and 2 are electrically... The pressure-current characteristics were found to be good.

[0376] Additionally, each light-emitting device is supplied with 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The diagram is shown in Figure 12. As described above, each light-emitting device has a microphone configured to enhance the blue light. A cavity structure is applied, as shown in Figure 12. Each light-emitting device is 451n The emission spectrum showed a maximum peak near m.

[0377] Reliability characteristics of light-emitting devices Next, reliability tests were performed on each light-emitting device. The results of the reliability tests are shown in Figure 13 and Figure 1. As shown in 4. In Figure 13, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%. The horizontal axis represents the operating time (h). In Figure 14, the vertical axis represents the voltage when the initial voltage is set to 0. The graph shows the change (ΔV), and the horizontal axis shows the operating time (h). Note that the reliability test was conducted with a current density of 5 0 mA / cm 2 The settings were configured, and each light-emitting device was driven.

[0378] As shown in Figure 13, in comparison device 3, although the brightness increases at the beginning of operation, thereafter, It was found that the brightness changes were large and unstable, such as a rapid decrease in brightness. On the other hand, Deba Chair 1 and device 2 show less long-term change in brightness compared to comparison device 3, and are high It was found to demonstrate reliability. Specifically, the LT90 of device 1 (brightness is 9 times the initial brightness) The time to decrease to 0% was 95 hours, and the LT90 for device 2 was 112 hours. On the other hand, the LT90 of comparison device 3 was 64 hours.

[0379] As shown in Figure 14, devices 1 and 2 exhibit a longer voltage range compared to the comparison device 3. It was found that the periodic changes were small and the voltage did not rise easily.

[0380] Device 1 and Device 2 consist of a first layer 821 containing Liq and a third layer which is a Li2O film. The comparison device 3 has a second layer 822 that does not contain Liq between layer 823 and layer 823. They are different. Compared to the configuration in which the first layer 821 and the third layer 823 are placed in contact, the first layer 82 The configuration in which a second layer 822 is placed between layer 1 and the third layer 823 improves the reliability of the light-emitting device. It was found that this could be improved. Also, from a comparison between device 1 and device 2, the second layer 8 For layer 22, the same organic compound as in the first layer 821 (ZADN in this example) may be used. It was found that different organic compounds (NBphen in this example) may also be used. [Examples]

[0381] In this example, a light-emitting device according to one aspect of the present invention is fabricated and the results of its evaluation are described. .

[0382] In this embodiment, as a light-emitting device, a device 4 to which one aspect of the present invention is applied, and a comparative device We will now describe the results of fabricating and evaluating the comparison device 5 used in this embodiment. The structures of chair 4 and comparison device 5 are shown in Figure 9B, and their specific configurations are shown in Table 3. For the methods of fabricating device 4 and comparative device 5, please refer to Example 1. The chemical formulas of the materials used in this example are shown below.

[0383] [Table 3]

[0384] [ka]

[0385] <<Operating characteristics of light-emitting devices>> The operating characteristics of device 4 and comparison device 5 were measured. The measurements were taken at room temperature (25°C). It was conducted in an atmosphere that was carefully maintained.

[0386] Figure 15 shows the brightness-current efficiency characteristics of each light-emitting device. Figure 16 shows the current efficiency characteristics of each light-emitting device. This shows the pressure-current characteristics.

[0387] Table 4 shows 1000 cd / m². 2 The main initial characteristic values ​​of each light-emitting device in the vicinity are shown.

[0388] [Table 4]

[0389] As shown in Figures 15, 16, and Table 4, device 4 has a higher brightness compared to comparison device 5. - It was found that the current efficiency characteristics and voltage-current characteristics were good.

[0390] Additionally, each light-emitting device has a current of 12.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The torque is shown in Figure 17. Each light-emitting device in this embodiment has a light-emitting unit that emits blue light. It has a tandem structure with two stacked layers. Each light-emitting device is contained in the light-emitting layers 813a and 813b. 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N- [phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,1 It originates from the emission of 0PCA2Nbf(IV)-02) and has a maximum peak around 457 nm. The emission spectrum was shown.

[0391] Reliability characteristics of light-emitting devices Next, reliability tests were performed on each light-emitting device. The results of the reliability tests are shown in Figure 18 and Figure 1. As shown in 9. In Figure 18, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%. The horizontal axis represents the operating time (h) of the element. In Figure 19, the vertical axis represents the initial voltage when it is set to 0. The voltage change (ΔV) is shown, and the horizontal axis shows the operating time (h). Note that the reliability test was conducted using the initial brightness... The degree is 5000 cd / m². 2 The settings were configured, and each light-emitting device was driven.

[0392] Based on the reliability test results, device 4 exhibits higher reliability compared to comparison device 5. This was found. Specifically, the LT95 of device 4 was 446 hours. On the other hand, the comparison device The LT95 for Chair 5 was less than an hour.

[0393] As shown in Figure 19, device 4 exhibits smaller long-term voltage fluctuations compared to comparison device 5. It was found that the voltage was less likely to rise.

[0394] Device 4 comprises a first layer 821 containing Liq and a third layer 823 which is a Li2O film. It differs from comparative device 5 in that it has a second layer 822 in which it does not contain Liq. Compared to a configuration in which layer 821 and the third layer 823 are placed in contact, the first layer 821 and the third layer 8 The configuration in which a second layer 822 is provided between 23 and 23 can improve the reliability of the light-emitting device. That's what I found out. [Explanation of symbols]

[0395] 201: Substrate, 202: Insulating layer, 202a: Insulating layer, 202b: Insulating layer, 203B: Light-emitting Device, 203G: Light-emitting device, 203R: Light-emitting device, 203W: Light-emitting device 204: Insulating layer, 205: Substrate, 206B: Color filter, 206G: Color fill T, 206R: Color filter, 207: Space, 208: Adhesive layer, 209: Black matrix Rix, 210: transistor, 211: first electrode, 212G: conductive layer, 212R: Conductive layer, 213: EL layer, 215: second electrode, 220B: optical distance, 220G: optical distance Separation, 220R: Optical distance, 301: Substrate, 302: Pixel section, 303: Circuit section, 304a: Circuit section, 304b: Circuit section, 305: Sealing material, 306: Circuit board, 307: Wiring, 308: FPC, 309: Transistor, 310: Transistor, 311: Transistor, 312 : Transistor, 313: First electrode, 314: Insulating layer, 315: EL layer, 316: Second Electrode, 317: Organic EL device, 318: Space, 320: Transistor, 321: Conductor Electromagnetic layer, 322a: conductive layer, 322b: conductive layer, 323: conductive layer, 324: insulating layer, 325 : insulating layer, 326: insulating layer, 327: semiconductor layer, 327i: channel formation region, 327n : Low resistance region, 328: insulating layer, 330: transistor, 331: conductive layer, 332a: conductive Electrode layer, 332b: conductive layer, 333: conductive layer, 334: insulating layer, 335: insulating layer, 337: Semiconductor layer, 338: insulating layer, 401: first electrode, 402: EL layer, 403: second electrode , 405: insulating layer, 406: conductive layer, 407: adhesive layer, 416: conductive layer, 420: substrate, 422: Adhesive layer, 423: Barrier layer, 424: Insulating layer, 450: Organic EL device, 49 0a: Substrate, 490b: Substrate, 490c: Barrier layer, 800: Substrate, 801: First electrode , 803: second electrode, 811a: hole injection layer, 811b: hole injection layer, 812a1: positive Hole transport layer, 812a2: Hole transport layer, 812b: Hole transport layer, 813a: Light-emitting layer, 813 b: light-emitting layer, 813b1: light-emitting layer, 813b2: light-emitting layer, 813b3: light-emitting layer, 814b 1: electron transport layer, 814b2: electron transport layer, 815b: electron injection layer, 821: first layer, 822: Second layer, 823: Third layer, 824: Fourth layer, 1101: First electrode, 11 03: Second electrode, 1105a: Functional layer, 1105b: Functional layer, 1105c: Functional layer, 1 105d: Functional layer, 1111a: Hole injection layer, 1111b: Hole injection layer, 1112a: Hole transport layer, 1112a1: Hole transport layer, 1112a2: Hole transport layer, 1112b: Hole transport Transmitting layer, 1113a: Emitting layer, 1113b: Emitting layer, 1113c: Emitting layer, 1114b: Electric 1115b: electron transport layer, 1121: electron injection layer, 1122: first layer, 112 3: Third layer, 1124: Fourth layer, 7000: Display unit, 7001: Display unit, 7100: Television equipment, 7101: housing, 7103: stand, 7111: remote control unit, 7200: Notebook personal computer, 7211: Enclosure, 7212: Keyboard 7213: Pointing device, 7214: External connection port, 7300: Digital sensor Inage, 7301: enclosure, 7303: speaker, 7311: information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 7600: Portable information terminal, 7 601: Casing, 7602: Hinge, 7650: Personal digital assistant, 7651: Display unit, 78 00: Personal Information Terminal, 7801: Band, 7802: Input / Output Terminal, 7803: Operation Button ,7804: Icon, 7805: Battery, 9700: Automobile, 9701: Car body, 97 02: Wheels, 9703: Windshield, 9704: Lights, 9705: Fog lights, 9710: Display section, 9711: Display section, 9712: Display section, 9713: Display section, 9714 :Display, 9715:Display, 9721:Display, 9722:Display, 9723:Display

Claims

1. The device comprises a first electrode, a first light-emitting layer, a first layer, a second layer, a third layer, a second light-emitting layer, and a second electrode, stacked in this order. The first layer of the present invention comprises a first organic compound and a first substance, The second layer has a second organic compound, The third layer has the second substance, The first organic compound is any of the following: anthracene derivative, tetracene derivative, phenanthrene derivative, pyrene derivative, chrysene derivative, dibenzo[g,p]chrysene derivative, zinc-based metal complex, aluminum-based metal complex, oxadiazole derivative, triazole derivative, benzimidazole derivative, quinoxaline derivative, dibenzoquinoxaline derivative, phenanthroline derivative, heterocyclic compound having a diazine skeleton, heterocyclic compound having a triazine skeleton, and heterocyclic compound having a pyridine skeleton. The second organic compound is any of the following: anthracene derivative, tetracene derivative, phenanthrene derivative, pyrene derivative, chrysene derivative, dibenzo[g,p]chrysene derivative, zinc-based metal complex, aluminum-based metal complex, oxadiazole derivative, triazole derivative, quinoxaline derivative, dibenzoquinoxaline derivative, phenanthroline derivative, heterocyclic compound having a diazine skeleton, heterocyclic compound having a triazine skeleton, and heterocyclic compound having a pyridine skeleton. The first organic compound and the second organic compound are different substances. The first substance is a metal, a metal salt, a metal oxide, or an organometallic salt. The second material described above is an electron-injection material, A light-emitting device in which the first and second materials are different materials.

2. In claim 1, The second layer is a light-emitting device that does not contain the first material.

3. In claim 1 or claim 2, The third layer further comprises a third organic compound, The third organic compound is an electron transport material, which is a light-emitting device.

4. In claim 3, A light-emitting device wherein the third organic compound is the same organic compound as at least one of the first organic compound and the second organic compound.

5. In any one of claims 1 to 4, The first substance is an organometallic complex having an alkali metal or alkaline earth metal, wherein the light-emitting device is an organometallic complex.

6. In any one of claims 1 to 5, The first substance is an organometallic complex having a ligand containing nitrogen and oxygen, and an alkali metal or alkaline earth metal, in a light-emitting device.

7. In any one of claims 1 to 6, The first substance is an organometallic complex having a quinolinol ligand and an alkali metal or alkaline earth metal, in a light-emitting device.

8. In any one of claims 1 to 7, The second substance is an alkali metal, alkaline earth metal, or rare earth metal, and the light-emitting device is a light-emitting device.

9. In any one of claims 1 to 8, The first organic compound has a HOMO level of -6.0 eV or higher, and an electron mobility of 1 × 10⁻¹⁶ at a square root of 600 electric field strength [V / cm]. －７ cm ２ / Vs or more 5×10 －５ cm ２ A light-emitting device whose Vs is less than or equal to / Vs.

10. In any one of claims 1 to 9, The first layer has a first region on the side of the first light-emitting layer and a second region on the side of the second light-emitting layer. A light-emitting device in which the first region and the second region have different concentration ratios of the first organic compound and the first substance.

11. In any one of claims 1 to 9, The first layer has a first region on the side of the first light-emitting layer and a second region on the side of the second light-emitting layer. A light-emitting device in which the second region has a lower concentration of the first substance than the first region.

12. In any one of claims 1 to 11, Furthermore, it has a hole injection layer, The hole injection layer is located between the first electrode and the first light-emitting layer. The hole injection layer comprises a first compound and a second compound, The first compound has electron-accepting properties for the second compound, A light-emitting device in which the HOMO level of the second compound is between -5.7 eV and -5.4 eV.

13. In claim 12, Furthermore, it has a first hole transport layer, The first hole transport layer is located between the hole injection layer and the first light-emitting layer. The first hole transport layer has a third compound, The HOMO level of the third compound is less than or equal to the HOMO level of the second compound. A light-emitting device in which the difference between the HOMO level of the third compound and the HOMO level of the second compound is within 0.2 eV.

14. In claim 13, The second compound and the third compound each have at least one of the following: a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton, respectively, in a light-emitting device.

15. In claim 13, Furthermore, it has a second hole transport layer, The second hole transport layer is located between the first hole transport layer and the first light-emitting layer. The second hole transport layer has a fourth compound, A light-emitting device wherein the HOMO level of the fourth compound is lower than that of the third compound.

16. In claim 15, A light-emitting device wherein the second compound, the third compound, and the fourth compound each have at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton.

17. In any one of claims 1 to 16, The first light-emitting layer is a light-emitting device having a light-emitting material that emits blue light.

18. In any one of claims 1 to 16, The first light-emitting layer is a light-emitting device having a fluorescent material that emits blue light.

19. A light-emitting device according to any one of claims 1 to 18, A light-emitting device comprising at least one of a transistor and a substrate.

20. The light-emitting device according to claim 19, A light-emitting module having at least one of a connector and an integrated circuit.

21. The light-emitting module according to claim 20, An electronic device having at least one of the following: an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operating button.

22. A light-emitting device according to any one of claims 1 to 18, A lighting device comprising at least one of a housing, a cover, and a support base.

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