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

Abstract

To provide a light-emitting element with high luminescence efficiency, which has a fluorescent light-emitting material. [Solution] The solution comprises a fluorescent light-emitting material and a host material, wherein the host material is a first organic compound The first organic compound and the second organic compound are the first An organic compound and a second organic compound have the function of forming an excited complex, and the excited complex exhibits The emission is characterized by a delayed fluorescence component accounting for 5% or more of the emission, and the delayed fluorescence component has a fluorescence lifetime of 1 It has a delayed fluorescence component with a duration of 0 ns to 50 μs.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a light-emitting element, or a display device having the light-emitting element, an electronic device, and a light Regarding lighting equipment.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. One aspect of the technical field relates to a product, method, or method of manufacture. Or, one aspect of the present invention. This refers to a process, machine, manufacture, or composition. Regarding the ter. Therefore, the technical aspects of one aspect of the present invention disclosed more specifically herein Examples include semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, energy storage devices, and memory devices. Examples include devices, methods for driving them, or methods for manufacturing them. . [Background technology]

[0003] In recent years, electroluminescence (EL) Research and development of light-emitting devices using this technology are actively underway. The basic configuration of these light-emitting devices is The device has a configuration in which a layer containing a light-emitting material (EL layer) is sandwiched between a pair of electrodes. By applying a voltage between them, light emission can be obtained from the light-emitting material.

[0004] Since the aforementioned light-emitting element is self-illuminating, the display device using it offers excellent visibility and battery life. It has advantages such as not requiring crystalline materials and consuming less power. Furthermore, it can be manufactured to be thin and lightweight. It also has advantages such as a high response speed.

[0005] An organic compound is used as the luminescent material, and an EL layer containing the luminescent material is provided between a pair of electrodes. In the case of a light-emitting element (for example, an organic EL element), by applying a voltage between a pair of electrodes... Electrons are injected from the cathode and holes from the anode into the light-emitting EL layer. A flow occurs. Then, the injected electrons and holes recombine to form a luminescent organic compound. The compound enters an excited state, and light emission can be obtained from the excited luminescent organic compound.

[0006] The types of excited states that organic compounds can form include singlet excited states (S * ) and triplet excitation Status (T * ) and the emission from the singlet excited state is fluorescence, and the emission from the triplet excited state is phosphorus It is called light. Also, the statistical generation ratio of these in light-emitting elements is S * :T * = The ratio is 1:3. Therefore, compared to light-emitting elements using fluorescent compounds, Light-emitting devices using phosphorescent compounds (phosphorescent compounds) can achieve higher luminescence efficiency. This becomes possible. Therefore, phosphorescent compounds that can convert triplet excited states into luminescence. In recent years, there has been a great deal of activity in developing light-emitting elements using [this technology].

[0007] Among light-emitting devices using phosphorescent compounds, in particular, light-emitting devices that emit blue light, Because it is difficult to develop stable compounds with high triplet excitation energy levels, they are not yet in practical use. This has not yet been achieved. Therefore, development of light-emitting devices using more stable fluorescent compounds is underway. Therefore, methods are being explored to improve the luminescence efficiency of light-emitting devices (fluorescent light-emitting devices) using fluorescent compounds. It is being done.

[0008] As a material capable of converting a portion of the triplet excited state into light emission, thermally activated delayed fluorescence ( Thermally Activated Delayed Fluorescence :TADF) is a known form. In thermally activated delayed phosphors, the triplet excited state is reversed intersystem interaction. The difference generates a singlet excited state, which is then converted into light emission.

[0009] In light-emitting devices using thermally activated delayed phosphors, in order to increase the luminescence efficiency, thermal activation In delayed phosphors, not only is the singlet excited state efficiently generated from the triplet excited state, but The ability to efficiently obtain light emission from singlet excited states, i.e., a high fluorescence quantum yield. This is important. However, designing a light-emitting material that satisfies both conditions simultaneously is difficult. ru.

[0010] Therefore, in a light-emitting element having a thermally activated delayed phosphor and a fluorescent compound, The singlet excitation energy of the delayed-excitation phosphor is transferred to the fluorescent compound, and from the fluorescent compound... A method for obtaining light emission has been proposed (see Patent Document 1). [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2014-45179 [Overview of the project] [Problems that the invention aims to solve]

[0012] In a light-emitting element having a thermally activated delayed phosphor and a fluorescent compound, the luminescence efficiency is increased. To achieve this, it is preferable that the singlet excited state is efficiently generated from the triplet excited state. Furthermore, the singlet excited state of a thermally activated delayed phosphor can be efficiently converted to the singlet excited state of a fluorescent compound. It is preferable that energy is transferred. Also, the triplet excited state of the thermally activated delayed phosphor It is preferable to suppress energy transfer to the triplet excited state of the fluorescent compound.

[0013] Therefore, in one aspect of the present invention, a light-emitting element having a fluorescent compound and high luminescence efficiency is provided. One of the objectives is to provide a light-emitting device with reduced power consumption. Alternatively, in one aspect of the present invention, a light-emitting device with reduced power consumption is provided. One objective is to provide an element. Alternatively, in one aspect of the present invention, a novel light-emitting element is provided. One of the objectives is to provide a novel light-emitting device. Alternatively, in one aspect of the present invention, a novel light-emitting device is provided. One of the objectives is to provide a novel display device. Alternatively, in one aspect of the present invention, to provide a novel display device. This will be one of the challenges.

[0014] Furthermore, the description of the above problems does not preclude the existence of other problems. Also, one aspect of the present invention is not necessarily However, it is not necessary to solve all of these problems. Other issues not mentioned above should be described in the specification, etc. This is self-evident, and it is possible to extract issues other than those mentioned above from the description in the specification, etc. ru. [Means for solving the problem]

[0015] One aspect of the present invention is that the light-emitting element has a light-emitting layer that forms an excitation complex, thereby enabling triplet This is a light-emitting device that converts excitons into singlet excitons and can emit light from singlet excitons. Furthermore, the energy transfer of the singlet exciton can cause the fluorescent compound to emit light. It is a light-emitting element.

[0016] Therefore, one aspect of the present invention comprises a fluorescent material and a host material, and the host material It comprises a first organic compound and a second organic compound, and the first organic compound and the second The organic compounds have the function of forming an excited complex with the first organic compound and the second organic compound. The emission exhibited by the excited complex has a delayed fluorescence component accounting for 5% or more, and delayed fluorescence The component is a light-emitting element having a delayed fluorescence component with a fluorescence lifetime of 10 ns to 50 μs.

[0017] Furthermore, in the above configuration, the excitation complex has the function of supplying excitation energy to the fluorescent material. It is preferable to have it.

[0018] Furthermore, in each of the above configurations, the luminescence exhibited by the excited complex is the lowest energy of the fluorescent material. It is preferable that it has a region that overlaps with the absorption band on the ghee side.

[0019] Furthermore, in each of the above configurations, either the first organic compound or the second organic compound is electron The first organic compound or the other of the second organic compound has the function of transporting holes. Preferably, it has the function of having the first organic compound or the second organic compound. The first organic compound or the second organic compound has a π-electron-deficient heteroaromatic ring skeleton. The other side preferably has a π-electron-rich heteroaromatic ring skeleton or an aromatic amine skeleton.

[0020] Another aspect of the present invention involves the light-emitting element of each of the above configurations and a color filter or transistor. A display device having at least one of the ZISTA. Another aspect of the present invention is the The electronic device comprises a display device and at least one of a housing or a touch sensor. Furthermore, another aspect of the present invention relates to the light-emitting element of each of the above configurations and a housing or touch sensor. It is a lighting device having at least one of the following. Another aspect of the present invention is a lighting device having a light-emitting element. This includes not only optical devices but also electronic devices that have light-emitting devices. A light-emitting device refers to an image display device or a light source (including lighting devices). A connector for the optical device, for example, an FPC (Flexible Printed Circuit) t) Display module with TCP (Tape Carrier Package) attached A display module with a printed circuit board attached to the TCP, or a light-emitting element with a C The OG (Chip On Glass) method directly mounts the IC (integrated circuit) to the display. Modules may also include light-emitting devices. [Effects of the Invention]

[0021] According to one aspect of the present invention, a light-emitting element having a fluorescent compound and high luminescence efficiency is provided. This is possible. Alternatively, according to one aspect of the present invention, a light-emitting element with reduced power consumption can be provided. This can be done. Alternatively, according to one aspect of the present invention, a novel light-emitting element can be provided. Alternatively, according to one aspect of the present invention, a novel light-emitting device can be provided. In one aspect, a novel display device can be provided.

[0022] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention is: It is not necessarily required to have all of these effects. Other effects are described in the specification. This is obvious from the descriptions in the specifications, drawings, and claims, and the descriptions in the specifications, drawings, and claims Therefore, it is possible to extract effects other than those mentioned above. [Brief explanation of the drawing]

[0023] [Figure 1] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention, and a diagram illustrating the correlation of energy levels in the light-emitting layer. [Figure 2]A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention, and a diagram illustrating the correlation of energy levels in the light-emitting layer. [Figure 3] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention, and a diagram illustrating the correlation of energy levels in the light-emitting layer. [Figure 4] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. [Figure 5] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. [Figure 6] A schematic cross-sectional diagram illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 7] A schematic cross-sectional diagram illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 8] A top view and a schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 9] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 10] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 11] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 12] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 13] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 14] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 15] A block diagram and a circuit diagram illustrating a display device according to one embodiment of the present invention. [Figure 16] A circuit diagram illustrating the pixel circuit of a display device according to one embodiment of the present invention. [Figure 17] A circuit diagram illustrating the pixel circuit of a display device according to one embodiment of the present invention. [Figure 18] A perspective view showing an example of a touch panel according to one aspect of the present invention. [Figure 19] A cross-sectional view showing an example of a display device and a touch sensor according to one embodiment of the present invention. [Figure 20] A cross-sectional view showing an example of a touch panel according to one aspect of the present invention. [Figure 21]A block diagram and timing chart diagram of a touch sensor according to one aspect of the present invention. [Figure 22] A circuit diagram of a touch sensor according to one aspect of the present invention. [Figure 23] A perspective view illustrating a display module according to one embodiment of the present invention. [Figure 24] A diagram illustrating an electronic device according to one embodiment of the present invention. [Figure 25] A perspective view and a cross-sectional view illustrating a light-emitting device according to one embodiment of the present invention. [Figure 26] A cross-sectional view illustrating a light-emitting device according to one embodiment of the present invention. [Figure 27] A diagram illustrating a lighting device and electronic equipment according to one embodiment of the present invention. [Figure 28] A diagram illustrating a lighting device according to one embodiment of the present invention. [Figure 29] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 30] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 31] A diagram illustrating the brightness-voltage characteristics of a light-emitting element according to an embodiment. [Figure 32] A diagram illustrating the electroluminescence spectrum of a light-emitting element according to an embodiment. [Figure 33] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 34] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 35] A diagram illustrating the brightness-voltage characteristics of a light-emitting element according to an embodiment. [Figure 36] A diagram illustrating the electroluminescence spectrum of a light-emitting element according to an embodiment. [Figure 37] A diagram illustrating the emission spectrum of a thin film according to the example. [Figure 38] A diagram illustrating the absorption spectrum of the solution according to the example. [Figure 39] A diagram illustrating the results of time-resolved fluorescence measurement of a thin film according to the example. [Modes for carrying out the invention]

[0024] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is as follows The description is not limited to the present invention, and the form and details may not depart from the spirit and scope of the present invention. It is possible to change this in various ways. Therefore, the present invention can be described in the embodiments shown below. It is not interpreted as being limited to volume.

[0025] For the sake of ease of understanding, the position, size, and scope of each component shown in the drawings, etc., are as follows: The actual location, size, and range may not be represented. Therefore, the disclosed invention may not reflect the actual location, size, or range. It is not necessarily limited to the location, size, or scope disclosed in drawings, etc.

[0026] Furthermore, in this specification, the ordinal numbers used as "1st," "2nd," etc., are used for convenience. The order of processes or stacking may not be indicated. For example, "the first" may be written as "the second" or This can be replaced with "third," etc., as appropriate in the explanation. The ordinal numbers used to specify one aspect of this invention may not be the same. be.

[0027] Furthermore, in this specification and other documents, when describing the structure of the invention using drawings, the same thing is used The symbols used may be consistent across different drawings.

[0028] Furthermore, in this specification, the terms "membrane" and "layer" are interchangeable. It is possible to change the term. For example, the term "conductive layer" can be changed to the term "conductive film." It may be possible to change it. Or, for example, change the term "insulating film" to "insulating layer". In some cases, it may be possible to change the terminology to this.

[0029] Furthermore, in this specification, etc., singlet excited state (S * ) is a single with excitation energy This refers to a singlet state. Furthermore, the lowest singlet excitation energy level (S1 level) is: This refers to the lowest excitation energy level of a singlet excited state. Also, the triplet excited state (T * ) is a triplet state that has excitation energy. The lowest energy level (T1 level) is the same as the excitation energy level of the lowest triplet excited state. And so it is.

[0030] Furthermore, in this specification, a fluorescent material or fluorescent compound refers to a state from a singlet excited state to a ground state. A material or compound that emits light in the visible light region when relaxed into a certain state. Phosphorescent compounds are compounds that, when relaxing from a triplet excited state to a ground state, emit visible light at room temperature. It is a material or compound that gives light to a region. In other words, phosphorescent materials or phosphorescent compounds are It is one of the materials or compounds capable of converting triplet excitation energy into visible light.

[0031] In this specification, room temperature refers to any temperature between 0°C and 40°C.

[0032] Furthermore, in this specification, the blue wavelength region refers to waves between 400 nm and 490 nm. It is a long wavelength region, and the blue emission has at least one emission spectral peak in that wavelength region. Furthermore, the green wavelength range is the wavelength range of 490 nm to less than 580 nm, and green The emission has at least one emission spectral peak in the wavelength region. Also, the red wave The long wavelength region is the wavelength range of 580 nm to 680 nm, and red emission occurs in this wavelength region. It has at least one emission spectral peak.

[0033] (Embodiment 1) In this embodiment, a light-emitting element according to one aspect of the present invention will be described below with reference to Figure 1.

[0034] <Example of light-emitting element configuration> First, regarding the configuration of a light-emitting element according to one aspect of the present invention, using Figures 1(A), (B), and (C) I will explain below.

[0035] Figure 1(A) is a schematic cross-sectional view of a light-emitting element 250 according to one embodiment of the present invention.

[0036] The light-emitting element 250 has a pair of electrodes (electrode 101 and electrode 102), and between the pair of electrodes It has an EL layer 100 provided therein. The EL layer 100 has at least an emissive layer 130. .

[0037] Furthermore, the EL layer 100 shown in Figure 1(A) includes, in addition to the light-emitting layer 130, a hole injection layer 111, and It has functional layers such as a pore transport layer 112, an electron transport layer 118, and an electron injection layer 119.

[0038] In this embodiment, of the pair of electrodes, electrode 101 is used as the anode, and electrode 1 Although 02 is described as the cathode, this is not the case for the configuration of the light-emitting element 250. Then, electrode 101 is used as the cathode and electrode 102 as the anode, and the stacking of each layer between these electrodes is done in the reverse order. It may also be arranged in this order. That is, from the anode side, a hole injection layer 111, a hole transport layer 112, and The order in which the optical layer 130, electron transport layer 118, and electron injection layer 119 are stacked should be as follows. .

[0039] Note that the configuration of the EL layer 100 is not limited to the configuration shown in Figure 1(A), and the hole injection layer 111 At least one of the hole transport layer 112, electron transport layer 118, and electron injection layer 119 selected It is sufficient to have a configuration that has one of either. Alternatively, the EL layer 100 can be a hole or electron injection To reduce barriers, improve hole or electron transport, or inhibit hole or electron transport. It has a functional layer that has functions such as being able to suppress the quenching phenomenon caused by electrodes. It may also be configured as follows. Note that even if each functional layer is a single layer, a configuration in which multiple layers are stacked may also be possible. It may be possible.

[0040] Figure 1(B) is a schematic cross-sectional view showing an example of the light-emitting layer 130 shown in Figure 1(A). The light-emitting layer 130 shown in B) has a host material 131 and a guest material 132. The host material 131 comprises organic compound 131_1 and organic compound 131_2.

[0041] Furthermore, as the guest material 132, any luminescent organic compound may be used. As for the chemical compounds, they are substances that can emit fluorescence (hereinafter also called fluorescent compounds). This is preferable. In the following description, a fluorescent compound is used as guest material 132. The configuration will be explained below. Note that guest material 132 is a fluorescent material or a fluorescent compound. You may interpret it differently.

[0042] In one embodiment of the present invention, the light-emitting element 250 comprises a pair of electrodes (electrode 101 and electrode 102 By applying a voltage between them, electrons are released from the cathode and holes from the anode. The electrons and holes are injected into the EL layer 100, and an electric current flows. Then, the injected electrons and holes recombine. By doing so, excitons are formed. This is produced by the recombination of carriers (electrons and holes). Of the excitons produced, the ratio of singlet excitons to triplet excitons (hereinafter referred to as the exciton production probability) is statistically determined. The probability ratio is 1:3. Therefore, in a light-emitting device using a fluorescent material, The proportion of singlet excitons that contribute to emission is 25%, while the proportion of triplet excitons that do not contribute to emission is 25%. The proportion of these generated is 75%. Therefore, triplet excitons that do not contribute to luminescence are used for luminescence. Converting to singlet excitons is important for improving the luminescence efficiency of light-emitting devices. That is the case.

[0043] <Light-emitting mechanism of light-emitting element> Next, the light-emitting mechanism of the light-emitting layer 130 will be explained below.

[0044] The organic compound 131_1 and organic compound contained in the host material 131 in the light-emitting layer 130 Substance 131_2 is an excited complex (exciplex, exciplex or Excipl Forms an ex (also called ex).

[0045] The combination of organic compound 131_1 and organic compound 131_2 forms an excited complex. Any combination that allows for this is acceptable, but one of them must have the function of transporting holes (hole transportability). It is a compound that does one function, and the other is a compound that has the function of transporting electrons (electron transport properties). However, this is more preferable. In this case, it becomes easier to form a donor-acceptor type excitation complex. It is possible to efficiently form excited complexes. Also, organic compound 131_1 and organic compound 1 The combination with 31_2 involves a compound with hole transport properties and a compound with electron transport properties. In the case of a combination, the carrier balance can be easily controlled by the mixing ratio. This is possible. Specifically, the ratio of hole-transporting compounds to electron-transporting compounds is 1:9. A range of 9:1 (weight ratio) is preferred. Furthermore, having this configuration makes it easy to carry Because the balance can be controlled, the control of the carrier recombination region can also be simplified. It is possible.

[0046] Furthermore, as a combination of host materials that efficiently form excited complexes, organic compound 13 The highest occupied orbital of one of 1_1 and organic compound 131_2 The pied Molecular Orbital (also called HOMO) level is the same as the other HO level. Higher than the MO level, and one of the lowest unoccupied orbits (Lowest Unoccupied Mole The cular orbital (also called LUMO) level is higher than the other LUMO level. This is preferable. For example, one organic compound has hole transport properties, and the other organic compound has electron transport properties. If transportability is present, the HOMO level of one organic compound is the HOMO level of the other organic compound. It is preferable that the LUMO level of one organic compound is higher than the LUMO level of the other organic compound. It is preferable that the level is higher than the MO level. Specifically, the HOMO level of one organic compound and the other The energy difference between the HOMO level of the organic compound is preferably 0.05 eV or more. More preferably, it is 0.1 eV or higher, and even more preferably 0.2 eV or higher. The energy difference between the LUMO level of one organic compound and the LUMO level of the other organic compound is Preferably 0.05 eV or higher, more preferably 0.1 eV or higher, and even more preferably The voltage is 0.2 eV or higher.

[0047] Organic compound 131_1, organic compound 131_2, and guest material in the light-emitting layer 130 The correlation of the energy levels with 132 is shown in Fig. 1(C). The notations and symbols in Fig. 1(C) are as follows. ·Host(131_1): Organic compound 131_1 ·Host(131_2): Organic compound 131_2 ·Guest(132): Guest material 132 (fluorescent compound) ·S H : S1 level of organic compound 131_1 (host material) ·T H : T1 level of organic compound 131_1 (host material) ·S G : S1 level of guest material 132 (fluorescent compound) ·T G : T1 level of guest material 132 (fluorescent compound) ·S E : S1 level of exciplex ·T E : T1 level of exciplex

[0048] In the light-emitting device according to one aspect of the present invention, the organic compound 131_1 and the organic compound 131_2 included in the light-emitting layer 130 form an exciplex. The lowest singlet excitation energy level (S E ) of the exciplex and the lowest triplet excitation energy level (T E ) of the exciplex are adjacent energy levels to each other (see Route E3 in Fig. 1(C)).

[0049] An exciplex is an excited state composed of two kinds of substances. In the case of photoexcitation, it is formed by the interaction of one substance in the excited state with the other substance in the ground state. And when it returns to the ground state by emitting light, the two substances that formed the exciplex behave again as the original separate substances. In the case of electrical excitation, when one becomes excited, it quickly forms an exciplex by interacting with the other. Alternatively, when one has a hole and the other has an electron ​ By receiving a molecule, it can rapidly form an excited complex. In this case, either substance Even in this case, an excited complex can be formed without forming an excited state, so the luminescent layer 1 Most of the excitons in 30 can exist as excited complexes. Excitation energy level (S E or T E ) is a host material (organic compound) that forms an excited complex. Singlet excitation energy levels (S) of 131_1 and organic compound 131_2 H ) lower Therefore, it is possible to form an excited state of the host material 131 at a lower excitation energy. This allows the driving voltage of the light-emitting element 250 to be reduced.

[0050] Singlet excitation energy level of the excited complex (S E ) and triplet excitation energy level (T E )teeth Because they are adjacent energy levels, they exhibit the function of thermally activated delayed fluorescence. In other words, the excited complex obtains its triplet excitation energy through reverse intersystem crossing (upconversion). It has the function of converting to singlet excitation energy (see Figure 1(C) Root E4). Therefore, a portion of the triplet excitation energy generated in the light-emitting layer 130 is converted to singlet by the excitation complex. It is converted into excitation energy. For this to happen, the singlet excitation energy level (S) of the excited complex must be E ) and triplet excitation energy level (T E The energy difference with ) is greater than 0 eV, which is 0.2 eV. It is preferable that the value is less than or equal to V. In order to efficiently generate reverse intersystem crossing, the excited complex Triplet excitation energy level (T E ) constitutes each of the host materials that form the excited complex Triplet excitation energy of organic compounds (organic compound 131_1 and organic compound 131_2) - Preferably lower than the level. This allows for the triplet excitation of the excited complex by each organic compound. This reduces the likelihood of an energy quench, allowing for efficient reverse intersystem crossing.

[0051] Furthermore, the singlet excitation energy level of the excited complex (S E ) is a singlet excitation of guest material 132. Electromotive force level (S G ) is preferably higher. By doing so, the excited complex produced The singlet excitation energy is the singlet excitation energy level (S) of the excited complex. E ) Guest materials Singlet excitation energy level of material 132 (S G Energy can be transferred to the guest Material 132 enters a singlet excited state and emits light (see Figure 1(C) Route E5).

[0052] Furthermore, in order to efficiently obtain luminescence from the singlet excited state of guest material 132, The fluorescence quantum yield of material 132 is preferably high, specifically preferably 50% or more. Preferably, it is 70% or more, and even more preferably 90% or more.

[0053] Note that the singlet excitation energy level of the excited complex (S E ) from guest material 132 triplet Excitation energy level (T G Energy transfer to ) is performed by singlet groups in guest material 132 Since direct transitions from the bottom state to the triplet excited state are forbidden, the main energy transfer is It's difficult to achieve that level.

[0054] Furthermore, the triplet excitation energy level of the excited complex (T E ) from guest material 132 triplet excitation Electromotive force level (TG When triplet excitation energy transfer occurs to ), the triplet excitation energy - becomes inactive (see Figure 1(C) Root E6). Therefore, the energy of Root E6 - Less movement reduces the efficiency of generating the triplet excited state of guest material 132. This is preferable because it can reduce thermal deactivation. For this purpose, the host material 131 and the gel The weight ratio with the stock material 132 is preferably such that the weight ratio of the guest material 132 is low. Preferably, the weight ratio of the guest material 132 to the host material 131 is 0.001 or higher. It is 0.05 or less, and more preferably 0.001 or more and 0.01 or less.

[0055] Furthermore, when the direct carrier recombination process becomes dominant in guest material 132, the emissive layer At 130, a large number of triplet excitons are generated, and thermal deactivation impairs the luminescence efficiency. Therefore, rather than the process of carriers directly recombining in guest material 132, The energy transfer process after the formation of the excited complex (Figure 1(C) Routes E4 and E5) A higher concentration of this compound can reduce the efficiency of generating the triplet excited state of guest material 132, and heat This is preferable because it can suppress deactivation. For this purpose, the host material 131 and the gel The weight ratio with the stock material 132 is preferably such that the weight ratio of the guest material 132 is low. Preferably, the weight ratio of the guest material 132 to the host material 131 is 0.001 or higher. It is 0.05 or less, and more preferably 0.001 or more and 0.01 or less.

[0056] As described above, if all of the energy transfer processes in routes E4 and E5 occur efficiently, If both the singlet and triplet excitation energies of the host material 131 are efficiently obtained Because it is converted to the singlet excited state energy of the guest material 132, the light-emitting element 250 This makes it possible to emit light with high luminous efficiency.

[0057] The processes of routes E3, E4, and E5 shown above are referred to as ExSET( in this specification, etc.) Exciplex-Singlet Energy Transfer (or ExEF) It is sometimes referred to as (Exciplex-Enhanced Fluorescence). Yes. In other words, the luminescent layer 130 provides the excitation energy from the excited complex to the guest material 132. There is a provision of that.

[0058] By configuring the light-emitting layer 130 as described above, the light emitted from the guest material 132 of the light-emitting layer 130 is achieved. It can be obtained efficiently.

[0059] <Energy transfer mechanism> Next, the control of the intermolecular energy transfer process between the host material 131 and the guest material 132. Let's explain the factors. The mechanism of energy transfer between molecules is the Förster mechanism (bi Two mechanisms have been proposed: the polar-dipole interaction and the Dexter mechanism (electron exchange interaction). Here, the intermolecular energy transfer between the host material 131 and the guest material 132 is described. The process will be explained below, and the same applies when the host material 131 is an excited complex.

[0060] ≪Förster mechanism≫ In the Förster mechanism, energy transfer does not require direct contact between molecules, and the host Energy transfer occurs through the resonance phenomenon of dipole vibrations between material 131 and guest material 132. This is due to the resonance phenomenon of dipole oscillation, which transfers energy from the host material 131 to the guest material 132. The excited host material 131 returns to the ground state, and the guest material 13 returns to the ground state. 2 enters an excited state. Note that the rate constant k of the Förster mechanism is... h*→g This is shown in equation (1). .

[0061]

number

[0062] In equation (1), ν represents the frequency, and f' h (ν) is a standard for host material 131. Emission spectra (when discussing energy transfer from singlet excited states, fluorescence spectra are used) When discussing energy transfer from triplet excited states, the phosphorescent spectrum is used. ε g (ν) represents the molar extinction coefficient of guest material 132, N represents Avogadro's number, and n represents the refractive index of the medium, and R represents the intermolecular distance between the host material 131 and the guest material 132. τ represents the measured lifetime of the excited state (fluorescence lifetime or phosphorescence lifetime), and c represents the speed of light. φ is the emission quantum yield (when discussing energy transfer from singlet excited states, this refers to the fluorescence quantum yield). The rate (or phosphorescent quantum yield when discussing energy transfer from triplet excited states) is expressed as K. 2 teeth , a coefficient representing the orientation of the transition dipole moments of the host material 131 and the guest material 132 (0 or 4) is the case. Note that in the case of random orientation, K 2 = 2 / 3

[0063] Dexter Mechanism In the Dexter mechanism, the host material 131 and the guest material 132 come into contact with each other to create an orbital overlap. Approaching within effective contact distance, electrons from the excited host material 131 and the ground state guest material 13 Energy transfer occurs through the exchange of electrons with 2. Note that the rate constant k of the Dexter mechanism h*→g This is shown in equation (2).

[0064]

number

[0065] In equation (2), h is Planck's constant, and K is a constant with the dimension of energy. Here, ν represents the frequency, and f' h (ν) is the normalized luminescence of the host material 131. Pectol (When discussing energy transfer from singlet excited states, use fluorescence spectra, triplet When discussing energy transfer from an excited state, the phosphorescent spectrum is represented, and ε' g (ν) The normalized absorption spectrum of guest material 132 is shown, and L represents the effective molecular radius. R represents the intermolecular distance between the host material 131 and the guest material 132.

[0066] Here, the energy transfer efficiency φ from the host material 131 to the guest material 132 is present. ET is, number It is expressed by equation (3). k r This is the luminescence process of the host material 131 (energy from singlet excited state When discussing energy transfer, use fluorescence; when discussing energy transfer from triplet excited states, use phosphorus. This represents the velocity constant of light, k n This is related to the non-luminescent processes (thermal deactivation and intersystem crossing) of the host material 131. The rate constant is represented, and τ represents the measured lifetime of the excited state of the host material 131.

[0067]

number

[0068] From equation (3), the energy transfer efficiency φET In order to increase the speed of energy transfer degree constant k h*→g Increase the other competing rate constants k r +k n (=1 / τ) You'll understand that it's better if it's smaller.

[0069] ≪A concept for enhancing energy transfer≫ First, let's consider energy transfer via the Förster mechanism. Substitute equation (1) into equation (3). By inputting, τ can be eliminated. Therefore, in the case of the Förster mechanism, Ghee transport efficiency φ ET This does not depend on the lifetime τ of the excited state of the host material 131. Also, energy Energy transfer efficiency φ ET This discusses the luminescence quantum yield φ (energy transfer from singlet excited states). Therefore, a higher fluorescence quantum yield is preferable. Generally, triplet excitation of organic compounds The emission quantum yield from the initial state is very low at room temperature. Therefore, the host material 131 is three In the case of a multiplet excited state, the energy transfer process by the Förster mechanism can be ignored, and We only need to consider the case where material 131 is in a singlet excited state.

[0070] Furthermore, the emission spectrum of the host material 131 (discussing energy transfer from the singlet excited state) If you want to compare the fluorescence spectrum and the absorption spectrum of guest material 132 (from the singlet ground state), It is preferable that there is a large overlap with the absorption corresponding to the transition to the singlet excited state. A higher molar extinction coefficient for the guest material 132 is also preferable. This is because the host material 131 The emission spectrum and the absorption band that appears at the longest wavelength end of guest material 132 overlap. It tastes good. Furthermore, the direct transition from the singlet ground state to the triplet excited state in guest material 132 is... Since transfer is prohibited, the molar absorption rate involving the triplet excited state in guest material 132 The number is negligible. From this, the three guest material 132 by the Förster mechanism The energy transfer process to the doublet excited state can be ignored, and the guest material 132 reaches the singlet excited state. Only the energy transfer process of H needs to be considered. That is, in the Förster mechanism, H Energy from the singlet excited state of main material 131 to the singlet excited state of guest material 132 We just need to consider the process of movement.

[0071] Next, let's consider energy transfer via the Dexter mechanism. According to equation (2), the velocity constant k h*→g To increase the size, the emission spectrum of the host material 131 (from the singlet excited state) When discussing energy transfer, use fluorescence spectra and the absorption spectra of guest material 132. The greater the overlap with the absorption corresponding to the transition from the singlet ground state to the singlet excited state, the better. It can be seen that... Therefore, optimizing the energy transfer efficiency is important for the luminescence of the host material 131. The spectrum and the absorption band that appears at the longest wavelength end of guest material 132 overlap. It will be realized.

[0072] Furthermore, substituting equation (2) into equation (3) reveals the energy transfer in the Dexter mechanism. Efficiency φ ET It can be seen that it depends on τ. The Dexter mechanism is based on electron exchange. Since this is a ghee transfer process, it is a singlet excited state from the host material 131 to the guest material 132. Similar to energy transfer to the doublet excited state, from the triplet excited state of the host material 131, Energy transfer also occurs to the triplet excited state of material 132.

[0073] In one embodiment of the present invention, the guest material 132 is a fluorescent material, therefore It is preferable that the energy transfer efficiency to the triplet excited state of material 132 is low. Energy transfer effect based on the Dexter mechanism from host material 131 to guest material 132 A low rate is preferable, and the Förster mechanism from the host material 131 to the guest material 132. High energy transfer efficiency based on this is preferable.

[0074] As already mentioned, the energy transfer efficiency in the Förster mechanism is as follows: It does not depend on the lifetime τ of the excited state 1. On the other hand, the energy transfer efficiency in the Dexter mechanism This depends on the excitation lifetime τ of the host material 131 and the energy transfer effect in the Dexter mechanism. To reduce the rate, it is preferable that the excitation lifetime τ of the host material 131 is short.

[0075] Furthermore, similar to the energy transfer from the host material 131 to the guest material 132, the excited complex The energy transfer process from to guest material 132 is also related to the Förster mechanism and the Deck Energy transfer occurs through both mechanisms in the star mechanism.

[0076] Therefore, one aspect of the present invention provides an energy transfer mechanism that can efficiently transfer energy to the guest material 132. Organic compound 131, a combination that forms an excited complex having the function of an energy donor. The present invention provides a light-emitting element having _1 and organic compound 131_2 as the host material 131. The excited complexes formed by organic compound 131_1 and organic compound 131_2 are singlet excited It has the characteristic that the energy level and the triplet excitation energy level are in close proximity. Therefore, the transition from triplet excitons to singlet excitons generated in the light-emitting layer 130 (reverse intersystem crossover) This difference is likely to occur. Therefore, the singlet exciton generation efficiency in the light-emitting layer 130 is increased. Furthermore, it is possible to obtain an energy acceptor from the singlet excited state of the excited complex. In order to facilitate energy transfer to the singlet excited state of guest material 132, The emission spectrum of the complex and the longest wavelength (lowest energy) emission spectrum of guest material 132. It is preferable that the absorption band and the singlet excited state of guest material 132 overlap. This can increase the efficiency of production.

[0077] Furthermore, among the luminescence exhibited by the excited complex, the fluorescence lifetime of the thermally activated delayed fluorescence component is short. Preferably, the duration is 10 ns to 50 μs, more preferably 10 The duration is between ns and 40 μs, and more preferably between 10 ns and 30 μs.

[0078] Furthermore, the proportion of thermally activated delayed fluorescence components in the luminescence exhibited by the excited complex is high. Preferred. Specifically, the proportion of the luminescence exhibited by the excited complex that is accounted for by the thermally activated delayed fluorescence component. The blend is preferably 5% or more, more preferably 8% or more, and even more preferably 10% or more. .

[0079] <Material> Next, the details of the components of a light-emitting element according to one aspect of the present invention will be described below.

[0080] ≪Luminous layer≫ The materials that can be used for the light-emitting layer 130 are described below.

[0081] In the light-emitting layer 130, the host material 131 is the most abundant by weight, followed by the guest material 132 The (fluorescent material) is dispersed in the host material 131. Host material 131 of the light-emitting layer 130 ( The S1 levels of organic compounds 131_1 and 131_2 are guest levels of the luminescent layer 130. It is preferable that the level is higher than the S1 level of material 132 (fluorescent material). Also, the level of the luminescent layer 130 is The T1 level of material 131 (organic compound 131_1 and organic compound 131_2) is luminescent. It is preferable that the T1 level is higher than that of the guest material 132 (fluorescent material) in layer 130.

[0082] In the luminescent layer 130, there are no particular limitations on the guest material 132, but anthracene is also acceptable. Derivatives, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives, Lylene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxazine Derivatives, phenothiazine derivatives, etc., are preferred, and for example, the following materials can be used. .

[0083] 5,6-Bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-Bipy Lysine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-ant) [Lyl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N ,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-i Phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'- Bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene] -9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPr n), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'- Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carb Zole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine ( Abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diph Phenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diph phenyl-N-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole ru-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert -Butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4' -(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCB) APA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4) ,1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine ] (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl- 2-Anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA) ), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N' -Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N' ,N',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]cri Sen-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9 ,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3 -amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2- [Iyl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviated) Name: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N', N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9, 10-Bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'- Triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bi Su(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl) Phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N, N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 6 Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene , 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetrace n (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl} -6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ ij]Quinolysin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedin Toryl (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl) Tracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N, N,N',N'-Tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluora Nten-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6 -[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H -Benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene} Rhodanine dinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1 ,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[i j]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinit ril (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl yl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDC M), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2, 3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl yl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 5,10,15,20-tetraphenylbisbenzo[5,6]inden[1,2,3-c d:1’,2’,3’-lm]perylene, and the like.

[0084] As the organic compound 131_1, in addition to zinc and aluminum-based metal complexes, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzo quinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, and the like can be mentioned. As other examples, aromatic amines, carbazole derivatives, and the like can be mentioned.

[0085] In addition, the following hole-transporting materials and electron-transporting materials can be used.

[0086] As the hole-transporting material, a material with higher hole transportability than electrons can be used, 1 ×10 -6 cm2 It is preferable that the material has a hole mobility of / Vs or greater. Specifically This uses aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. This is possible. Furthermore, the hole-transporting material may be a polymer compound.

[0087] Examples of materials with high hole transport capabilities include, for example, aromatic amine compounds such as N,N' -di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDP) PA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino ]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl) [amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-di Amine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenic acid) Examples include [Lu]-N-phenylaminobenzene (abbreviation: DPA3B), etc.

[0088] Furthermore, as a carbazole derivative, specifically, 3-[N-(4-diphenylamino Phenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1) ), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9 -Phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenyl (Aminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation) :PCzTPN2), 3-[N-(9-phenylcarbazole-3-yl)-N-phenyl Luamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N- (9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarb Zol (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcate Luvazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) Examples include:

[0089] In addition, other carbazole derivatives include 4,4'-di(N-carbazolyl)bife Nyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]bene Zen (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl ]-9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazol) Phenyl-2,3,5,6-tetraphenylbenzene, etc., can be used.

[0090] Furthermore, examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2- Naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10- Di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene Tracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenyl Enyl anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)ant Helical (abbreviated as DNA), 9,10-diphenylanthracene (abbreviated as DPaNth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4- Methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9, 10-Bis[2-(1-naphthyl)phenyl]anthracene, 9,10-Bis[2-(1 -Naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di( (1-Naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naph thyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'- bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl , 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9' -bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11- tetra(tert-butyl)perylene, etc. can be mentioned. In addition, pentacene, coro nen, etc. can also be used. Thus, a hole mobility of 1×10 -6 cm 2 / Vs or more, and it is more preferable to use an aromatic hydrocarbon having 14 or more and 42 or less carbon atoms. [[ID=···]] Yes.

[0091] In addition, the aromatic hydrocarbon may have a vinyl skeleton. Examples of the aromatic hydrocarbon having a vinyl group include, for example, 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] anthracene (abbreviation: DPVPA), etc. Yes.

[0092] In addition, polymer compounds such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenyl ) nilamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( (abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis (phenyl)benzidine] (abbreviation: Poly-TPD), etc. can also be used. Yes.

[0093] ​ Furthermore, materials with high hole transport capabilities include, for example, 4,4'-bis[N-(1-naphthyl )-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD) or N,N'-bi Su(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4 '-diamine (abbreviation: TPD), 4,4',4''-tris(carbazole-9-yl) Triphenylamine (abbreviation: TCTA), 4,4',4''-tris[N-(1-naphthyl [Lu)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4' ,4''-Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA) ), 4,4',4''-Tris[N-(3-methylphenyl)-N-phenylamino] Riphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'- Bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4- Phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: B) PAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenyl Luamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluorene-2- Il)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl- 9H-Fluoren-2-yl)amino]-9H-Fluoren-7-yl}phenylamine (Abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-) Luoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl [N-phenylamino]spiro-9,9'-bifluorene (abbreviation: D PASF), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl) Diphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-diphenylamine) Phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP) ), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl) Riphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-( 9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNB) B) 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl)amine N (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl)- N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N ''-Triphenyl-N,N',N''-Tris(9-phenylcarbazole-3-yl) )Benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl)- N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carb Zole-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)- N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl Tyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 9,9-dimethyl-N- Phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]flu Oren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl- 9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine N (abbreviation: PCBASF), 2-[N-(9-phenylcarbazole-3-yl)-N- Phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7-bis [N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'- Bifluoren (abbreviation: DPA2SF), N-[4-(9H-carbazole-9-yl) [phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'- Bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-di Aromatic amine compounds such as methylfluorene-2,7-diamine (abbreviation: YGA2F), etc. It can also be used. Furthermore, 3-[4-(1-naphthyl)-phenyl]-9-phenyl -9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthril)-pheni [Lu]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3,3'-bis(9- Phenyl-9H-carbazole (abbreviation: PCCP), 1,3-bis(N-carbazolyl) )Benzene (abbreviation: mCP), 3,6-bis(3,5-diphenylphenyl)-9-phenyl Nilcarbazole (abbreviation: CzTP), 4-{3-[3-(9-phenyl-9H-fluorinated [Phenyl-9-yl]phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-I I) 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (Abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophen-4-yl)-be Nzen (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl- 9H-Fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-I) II) 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-f Phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4-[3-(triphenylene) Amines such as -2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II) Compounds, carbazole compounds, thiophene compounds, furan compounds, fluorene compounds, The following substances can be used: riphenylene compounds, phenanthrene compounds, etc. It is mainly 1 x 10 -6 cm 2 It is a material having a hole mobility of / Vs or greater. However, electrons Other materials may be used as long as they have high hole transport capabilities.

[0094] As electron-transporting materials, materials with higher electron transport capabilities than holes can be used, ×10 -6 cm 2 It is preferable that the material has an electron mobility of / Vs or higher. Examples of easily absorbed materials (materials with electron transport properties) include nitrogen-containing heteroaromatic compounds. Such π-electron-deficient heteroaromatic compounds and metal complexes can be used. Specifically, quinoline It contains a ligand, a benzoquinoline ligand, an oxazole ligand, or a thiazole ligand. Examples include metal complexes. Also, oxadiazole derivatives, triazole derivatives, and phena Examples include thoroline derivatives, pyridine derivatives, bipyridine derivatives, and pyrimidine derivatives. It can be done.

[0095] For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tri (4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), (10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2) ), bis(2-methyl-8-quinolinolate)(4-phenylphenolate)aluminum ( III) (Abbreviation: BAlq), Bis(8-quinolinolato)zinc(II) (Abbreviation: Znq) These include metal complexes having a quinoline skeleton or a benzoquinoline skeleton. Bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviation: ZnPBO) , bis[2-(2-benzothiazolyl)phenolate]zinc(II) (abbreviation: ZnBTZ) Metal complexes having oxazole-based or thiazole-based ligands can also be used. Furthermore, in addition to metal complexes, there are also 2-(4-biphenylyl)-5-(4-tert-butyl Phenyl)-1,3,4-oxadiazole (abbreviation: PBD) and 1,3-bis[5-( p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (Abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2 -yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl )-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1- Phenyl-1H-benzimidazole (abbreviation: TPBI), 2-[3-(dibenzothio) Fen-4-yl)phenyl]-1-phenyl-1H-benzoimidazole (abbreviation: mD) BTBIm-II), vasophenanthroline (abbreviation: BPhen), vasocuproin ( Abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,1 Heterocyclic compounds such as 0-phenanthroline (abbreviation: NBPhen), and 2-[3-(dibetholone). [Nzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mD) BTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3 -Il]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2- [3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h] Quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H- Carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzP) DBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[ f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(diben Zothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDB) TPDBq-II), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyri Midine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl) Phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-( 9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm) Heterocyclic compounds having a diazine skeleton, such as 2-{4-[3-(N-phenyl-9H- Carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diph It contains a triazine skeleton such as enyl-1,3,5-triazine (abbreviation: PCCzPTzn) heterocyclic compounds such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl] Pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)pheny Heterocyclic compounds having a pyridine skeleton, such as [L]benzene (abbreviation: TmPyPB), 4,4 '-Bis(5-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs) Any heteroaromatic compound can be used. Also, poly(2,5-pyridinediyl)( Abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-( Pyridine-3,5-diyl) (abbreviation: PF-Py), poly[(9,9-dioctyl ful)] (oren-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)(abbreviated) Polymer compounds such as (name: PF-BPy) can also be used. The substances described here are Mainly 1x10 -6 cm 2 It is a substance that has an electron mobility of / Vs or greater than a hole. Any material with high electron transport properties may be used, other than those mentioned above.

[0096] Organic compound 131_2 is a combination that can form an excited complex with organic compound 131_1. Specifically, the hole-transporting material and electron-transporting material described above will be used. This can be achieved. In this case, the excitation formed by organic compound 131_1 and organic compound 131_2 The emission peak of the activating complex is on the longest wavelength side (lowest energy side) of guest material 132 (fluorescent material). Overlapping with the absorption band of ), organic compound 131_1, organic compound 131_2, and Guess It is preferable to select material 132 (fluorescent material). This dramatically improves the luminescence efficiency. This allows for the creation of improved light-emitting elements.

[0097] The host material 131 (organic compound 131_1 and organic compound 13) of the light-emitting layer 130 1_2) It has the function of converting triplet excitation energy into singlet excitation energy. Any material will do. The function is to convert the triplet excitation energy into singlet excitation energy. In addition to excited complexes, other materials include thermally activated delayed fluorescence (THIT). Examples include ivated delayed fluorescence (TADF) materials. Therefore, the part that says "excited complex" should be read as "thermally activated delayed fluorescence material". It is acceptable to do so. Note that thermally activated delayed fluorescence materials refer to materials with triplet excitation energy levels and singlet excitation energy levels. The difference with the electromotive force level is small, and reverse intersystem crossing causes the triplet excited state to become a singlet excited state. It is a material that has the function of converting energy into a triplet excited state. It is possible to upconvert to a singlet excited state (reverse intersystem crossing) by thermal energy, It can efficiently exhibit luminescence (fluorescence) from the multiplet excited state. Furthermore, it can also produce thermally activated delayed-release fluorescent lamps. The conditions under which light can be efficiently obtained are the triplet excitation energy level and the singlet excitation energy level. The energy difference between the levels is preferably greater than 0 eV and 0.2 eV or less, and more preferably 0 One characteristic is that it is greater than eV and less than or equal to 0.1 eV.

[0098] Furthermore, materials exhibiting thermally activated delayed fluorescence can be obtained by reverse intersystem crossing from a triplet excited state on their own. The material may be capable of generating a multiplet excited state. The thermally activated delayed fluorescence material is one type of material. If it is composed of the following materials, for example, the following materials can be used.

[0099] First, there are fullerenes and their derivatives, acridine derivatives such as proflavin, and eosin. It can be produced. Also, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S) n) Metals containing platinum (Pt), indium (In), or palladium (Pd), etc. Examples include metal-containing porphyrins. For example, protoporph Fluorine-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-fluoride Tin complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (Sn F2 (Hemato IX), coproporphyrin tetramethyl ester - tin fluoride Complex (SnF2(Copro III-4Me)), octaethylporphyrin-fluoride Tin complex (SnF2(OEP)), Ethioporphyrin-tin fluoride complex (SnF2(E Examples include tio I)) and octaethylporphyrin-platinum chloride complex (PtCl2OEP). It can be done.

[0100] Furthermore, as a thermally activated delayed fluorescence material composed of one type of material, a π-electron-rich complex atom is an example. Heterocyclic compounds having aromatic rings and π-electron-deficient heteroaromatic rings can also be used. Specifically is 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3- a)Carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol [9-yl]phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PC) CzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4, 6-Diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5- Phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl Lu-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl- 9H-acridine-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN) , bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (Abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine] Examples include -9,9'-anthracene]-10'-one (abbreviated as ACRSA). Because the cyclic compounds have π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings, It is preferable due to its high transportability and hole transportability. Substances directly bonded to a heteroaromatic ring exhibit characteristics of both π-electron-rich heteroaromatic ring donor and π-electron-deficient heteroaromatic rings. Both the complex aromatic ring and the singlet excitation energy level and the triplet excitation energy level are strongly acceptor. This is particularly preferable because it reduces the difference in Ghee levels.

[0101] The light-emitting layer 130 can also be composed of two or more layers. For example, the first When the first light-emitting layer and the second light-emitting layer are stacked in order from the hole transport layer side to form the light-emitting layer 130, A material having hole transport properties is used as the host material for the first light-emitting layer, and the host material for the second light-emitting layer One such configuration involves using materials that possess electron-transporting properties.

[0102] Furthermore, in the light-emitting layer 130, materials other than the host material 131 and the guest material 132 are used. It's okay to have it.

[0103] ≪A pair of electrodes≫ Electrodes 101 and 102 have the function of injecting holes and electrons into the light-emitting layer 130. The poles 101 and 102 are made of metals, alloys, conductive compounds, and mixtures or laminates thereof. It can be formed using materials such as aluminum (Al). Other transition metals include silver (Ag), tungsten, chromium, molybdenum, copper, and titanium. , alkali metals such as lithium (Li) and cesium, calcium, magnesium (Mg) Group 2 metals such as ytterbium (Yb) can be used as transition metals. Rare earth metals may also be used. As for the alloy, an alloy containing the above metals can be used. Examples of conductive compounds include MgAg and AlLi. Indium tin oxide (ITO), silicon, or silicon oxide Contains indium tin oxide (abbreviated as ITSO) and indium zinc oxide (Indium Z Metal acids such as indium oxide (inc. Oxide), tungsten, and zinc-containing indium oxides. Examples include chemical compounds. Inorganic carbon-based materials such as graphene may be used as conductive compounds. As described above, by stacking multiple of these materials, electrodes 101 and 10 You may form one or both of the two.

[0104] Furthermore, the light emitted from the light-emitting layer 130 is emitted from one or both of electrodes 101 and 102. It is extracted through. Therefore, at least one of electrode 101 and electrode 102 is visible. It has the function of transmitting light. Conductive materials that have the function of transmitting light include those that transmit visible light. The excess rate is 40% or more and 100% or less, preferably 60% or more and 100% or less, and its resistance The resistance rate is 1 × 10⁻⁶ -2 Examples include conductive materials with an Ω·cm or less. Also, the electric component that extracts light. The pole is formed of a conductive material that has the function of transmitting light and the function of reflecting light. The conductive material may also have a visible light reflectance of 20% to 80%, preferably 4. The resistivity is between 0% and 70%, and its resistivity is 1 × 10⁻⁶ -2 Conductive materials with an impedance of Ω·cm or less One example is when using a material with low light transmittance, such as a metal or alloy, for the electrode that extracts light. Electrode 10 is provided with a thickness sufficient to transmit visible light (for example, a thickness of 1 nm to 10 nm). One or both of electrode 1 and electrode 102 may be formed.

[0105] Furthermore, in this specification, etc., electrodes having the function of transmitting light include electrodes that transmit visible light. Any material that is both functional and conductive can be used, for example, ITO as described above. In addition to the oxide conductive layer, it includes an oxide semiconductor layer or an organic conductive layer containing organic material. As an organic conductive layer containing organic matter, for example, an organic compound and an electron donor are used. A layer containing a composite material formed by mixing an organic compound and an electron acceptor. Examples include layers containing composite materials. Furthermore, the resistivity of the transparent conductive layer is preferably 1 x 10 5 Ω·cm or less, more preferably 1 × 10⁻⁶ 4 It is less than or equal to Ω·cm.

[0106] Furthermore, the film deposition methods for electrodes 101 and 102 include sputtering, vapor deposition, and printing. Coating method, MBE (Molecular Beam Epitaxy) method, CVD method, palpation Laser deposition, ALD (Atomic Layer Deposition), etc. are suitable. It can be used as appropriate.

[0107] ≪Hole Injection Layer≫ The hole injection layer 111 is a hole injection layer that receives holes from one of the pair of electrodes (electrode 101 or electrode 102). It has the function of promoting hole injection by reducing the injection barrier, for example, transition metal oxides, f It is formed by tarocyanine derivatives or aromatic amines, etc. Transition metal oxides and For example, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide Examples include manganese oxides. Phthalocyanine derivatives include phthalocyanine and Examples include metal phthalocyanines. Aromatic amines include benzidine derivatives and phenyl Examples include lendiamine derivatives. Polymer compounds such as polythiophene and polyaniline. It is also possible to use substances, for example, self-doped polythiophenes such as poly(ethylenedi(ethylenedi) Typical examples include oxythiophene / poly(styrene sulfonic acid).

[0108] As the hole injection layer 111, a hole transport material and a material that exhibits electron-accepting properties in relation to it are combined. A layer containing composite material can also be used. Alternatively, a layer containing an electron-accepting material and a positive A lamination of layers containing pore-transporting material may also be used. Between these materials, a steady state or electrical current may be maintained. Charge transfer is possible in the presence of an electron barrier. Examples of materials exhibiting electron-accepting properties include Kinojimeta. Organic acceptors such as chloranil derivatives and hexaazatriphenylene derivatives We can list the following: 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-Hexazatriphenylene (abbreviated) These are compounds that have electron-withdrawing groups (halogen groups or cyano groups), such as HAT-CN. Furthermore, transition metal oxides, such as oxides of Group 4 to Group 8 metals, can be used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, acid These include tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly toxic to the atmosphere. Among them, it is preferable because it is stable, has low hygroscopicity, and is easy to handle.

[0109] As a hole-transporting material, a material with higher hole transport capabilities than electron transport can be used, ×10 -6cm 2 It is preferable that the material has a hole mobility of / Vs or greater. Specifically Aromatic amines and calcine are listed as hole transport materials that can be used in the light-emitting layer 130. Basol derivatives, aromatic hydrocarbons, stilbene derivatives, etc., can be used. The hole-transporting material may be a polymer compound.

[0110] ≪Hole transport layer≫ The hole transport layer 112 is a layer containing a hole transportable material, and is an example of the material used for the hole injection layer 111. The materials shown can be used. The hole transport layer 112 is injected into the hole injection layer 111. Because it has the function of transporting holes to the light-emitting layer 130, the HOMO level of the hole injection layer 111 is the same as It is preferable to have the same or close HOMO level.

[0111] As the hole transport material mentioned above, use the material exemplified as the material for the hole injection layer 111. This is possible. Also, 1 x 10 -6 cm 2 The substance has a hole mobility of / Vs or greater. Preferred. However, if the material has higher hole transport than electron transport, other materials can be used. It is also acceptable. Furthermore, the layer containing a material with high hole transport properties may consist of not only a single layer, but also a single layer of the aforementioned material. The layers may consist of two or more layers stacked on top of each other.

[0112] ≪Electron transport layer≫ The electron transport layer 118 passes through the electron injection layer 119 to the other of the pair of electrodes (electrode 101 or electron It has the function of transporting electrons injected from pole 102) to the light-emitting layer 130. Electron transport material For this purpose, materials with higher electron transport capabilities than holes can be used, resulting in 1 × 10⁻⁶ -6 cm 2 It is preferable that the material has an electron mobility of / Vs or higher. Examples of materials (materials with electron transport properties) include π-electron-deficient types such as nitrogen-containing heteroaromatic compounds. Hetero-aromatic compounds and metal complexes can be used. Specifically, they can be used in the light-emitting layer 130. The electron transport materials listed as capable of this include quinoline ligands, benzoquinoline ligands, and oxalool. Examples include metal complexes having a zole ligand or a thiazole ligand. Also, oxal Diazole derivatives, triazole derivatives, phenanthroline derivatives, pyridine derivatives, Examples include pyridine derivatives and pyrimidine derivatives. Also, 1 × 10 -6 cm 2 / Vs It is preferable that the material has the above electron mobility. If the material is of high quality, materials other than those mentioned above may be used as the electron transport layer. The transport layer 118 may be a single layer, or two or more layers made of the above material may be stacked.

[0113] Furthermore, a layer for controlling the movement of electron carriers is provided between the electron transport layer 118 and the light-emitting layer 130. It is also acceptable to use materials with high electron transport properties, as described above, and materials with high electron trapping properties. A layer to which a small amount of is added, thereby suppressing the movement of electron carriers, carrier balance This makes it possible to adjust the balance. In this configuration, electrons penetrate the light-emitting layer. This has a significant effect in suppressing problems that may arise as a result (for example, a decrease in the lifespan of the device).

[0114] ≪Electron injection layer≫ The electron injection layer 119 promotes electron injection by reducing the electron injection barrier from the electrode 102. It has the function of being, for example, Group 1 metals, Group 2 metals, or their oxides and halides. Carbonates and the like can be used. In addition, the electron transport material shown above and the electron transport material therefor Composite materials exhibiting electron-donating properties can also be used. Examples of electron-donating materials include: Examples include Group 1 metals, Group 2 metals, or oxides thereof. Specifically These are lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). 2) Lithium oxide (LiO x Alkali metals, alkaline earth metals, or These compounds can be used. Also, rare compounds such as erbium fluoride (ErF3) can be used. Earth metal compounds can be used. In addition, electride can be used in the electron injection layer 119. This may also be the case. The electride may be, for example, a mixed oxide of calcium and aluminum. Examples include materials to which electrons are highly concentrated. In addition, the electron injection layer 119 is an electron transport layer 1 You may use any substance that can be used in category 18.

[0115] Furthermore, the electron injection layer 119 is a composite made by mixing an organic compound and an electron donor. Materials may be used. Such composite materials are created when electrons are released from the organic compound by an electron donor. Therefore, it exhibits excellent electron injection and electron transport properties. In this case, as an organic compound... Preferably, the material is one that is excellent at transporting the generated electrons, specifically, for example, the material described above. The electron transport layer 118 can be composed of materials (such as metal complexes or heteroaromatic compounds). The electron donor can be any substance that exhibits electron-donating properties towards organic compounds. Alkali metals, alkaline earth metals, and rare earth metals are preferred, as are lithium, cesium, Examples include magnesium, calcium, erbium, and ytterbium. Also, alkalis Lithium oxides and alkaline earth metal oxides are preferred, as are lithium oxides and calcium oxides. Examples include barium oxides. Additionally, Lewis bases such as magnesium oxide can be used. It is also possible to use organic compounds such as tetrathiafulvalene (abbreviated as TTF). It can also be done this way.

[0116] Furthermore, the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer are, These methods include vapor deposition (including vacuum deposition), inkjet printing, coating, and gravure printing. It can be formed by the above-mentioned method. In addition, the light-emitting layer, hole injection layer, hole transport layer, electron In addition to the materials mentioned above, the transport layer and electron injection layer may also contain inorganic compounds such as quantum dots or high-grade materials. Molecular compounds (oligomers, dendrimers, polymers, etc.) may also be used.

[0117] Quantum dots include colloidal quantum dots, alloy quantum dots, and core-shell quantum dots. You may also use type quantum dots, core quantum dots, etc. Also, groups 2, 16, and 13 Includes element groups of Group 15, Groups 13 and 17, Groups 11 and 17, or Groups 14 and 15. Quantum dots may be used. Alternatively, cadmium (Cd), selenium (Se), zinc (Zn) may be used. ), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium Quantum dots containing elements such as um (Ga), arsenic (As), and aluminum (Al) are used. It's okay to be there.

[0118] Circuit board Furthermore, a light-emitting element according to one aspect of the present invention is placed on a substrate made of glass, plastic, or the like. It is fine to manufacture it. In terms of the order in which it is manufactured on the substrate, it is fine to stack them in order from the electrode 101 side. You may also stack them sequentially starting from pole 102.

[0119] Examples of substrates on which a light-emitting element according to one aspect of the present invention can be formed include glass and quartz. , or plastic can be used. A flexible substrate may also be used. A substrate is a flexible substrate that can be bent, for example, polycarbonate Examples include plastic substrates made of nate, polyarylate, etc. Also, films, etc. Vapor-deposited films and the like can also be used in the manufacturing process of light-emitting elements and optical elements. Anything other than these that functions as a support is acceptable. Alternatively, light-emitting Any device that has the function of protecting the elements and optical elements is acceptable.

[0120] For example, in the present invention, a light-emitting element can be formed using various substrates. The type of substrate is not particularly limited. One example of such a substrate is a semiconductor substrate (e.g., a single crystal). Substrates (or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal Substrates, stainless steel substrates, substrates with stainless steel foil, tungsten Substrate, substrate having tungsten foil, flexible substrate, laminated film, fibrous Examples include paper or substrate films containing the material. An example of a glass substrate is barium phosphate. Examples include borosilicate glass, aluminoborsilicate glass, or soda-lime glass. Flexible Examples of substrates, laminated films, and base films include the following: For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Representative examples include polyethersulfone (PES) and polytetrafluoroethylene (PTFE). There are plastics. Or, for example, there are resins such as acrylic. Or, Examples include polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride. These include, for example, polyamide, polyimide, aramid, epoxy, and anomalous. Examples include metallized films or paper products.

[0121] Alternatively, a flexible substrate may be used as the substrate, and the light-emitting element may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting element. The release layer is provided on top of the light-emitting element. After partially or completely completing the child component, it is separated from the circuit board and used for transferring it to another circuit board. This allows for the transfer of light-emitting elements to substrates with poor heat resistance or flexible substrates. Oh, the aforementioned delamination layer has, for example, a laminated inorganic film structure of a tungsten film and a silicon oxide film. Configurations such as the one shown, or a configuration in which a resin film such as polyimide is formed on the substrate, can be used.

[0122] In other words, a light-emitting element is formed using one substrate, and then the light-emitting element is transferred to another substrate. The light-emitting element may be placed on a different substrate. An example of a substrate on which the light-emitting element is placed is the above In addition to the substrates mentioned above, there are also cellophane substrates, stone substrates, wood substrates, and cloth substrates (natural fibers (silk, cotton, Hemp), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate) (including t, cupro, rayon, recycled polyester, etc.), leather substrate, or rubber substrate. These substrates can be used to create light-emitting elements that are less prone to breakage and have high heat resistance. This can be a child, a lightweight light-emitting element, or a thinned light-emitting element.

[0123] Furthermore, a field-effect transistor (FET), for example, is formed on the aforementioned substrate, and the FET and The light-emitting element 250 may be fabricated on electrically connected electrodes. This allows the FET to This allows us to create an active-matrix type display device that controls the driving of light-emitting elements.

[0124] In this embodiment, one aspect of the present invention has been described. Or, other embodiments may be described. In this context, one aspect of the present invention will be described. However, this aspect of the present invention is not limited to these. Not done. For example, in one aspect of the present invention, the light-emitting element has a fluorescent material and a host material The example shown illustrates a case where the host material has a first organic compound and a second organic compound. One aspect of the present invention is not limited thereto. Depending on the circumstances, the present invention may be used in some cases or situations. In one embodiment, for example, the host material contains a first organic compound or a second organic compound. It is not necessary. Alternatively, for example, in one aspect of the present invention, the excited complex may last for 10 ns to 50 μm. An example has been shown of a case where there is a delayed fluorescence component having a fluorescence lifetime of s or less, but one aspect of the present invention is , but not limited to, in some cases or depending on the circumstances, in one aspect of the present invention, For example, the excitation complex may have a delayed fluorescence component with a fluorescence lifetime of less than 10 ns. For example, even if the excited complex has a delayed fluorescence component with a fluorescence lifetime greater than 50 μs Good. Or, for example, in one aspect of the present invention, the luminescence exhibited by the excited complex is the delayed fluorescence component While an example of a case where the proportion is 5% or more has been shown, one aspect of the present invention is not limited thereto. In some cases, or depending on the circumstances, in one aspect of the present invention, for example, the excited complex is The resulting luminescence may have a delayed fluorescence component accounting for less than 5%.

[0125] The configuration shown in this embodiment can be used in appropriate combination with other embodiments. Cut.

[0126] (Embodiment 2) In this embodiment, the light-emitting element has a configuration different from that shown in Embodiment 1, and The light-emitting mechanism of the light-emitting element will be explained below using Figures 2 and 3. In Figure 3, the parts having the same function as those indicated by the symbols in Figure 1(A) are indicated by similar hatch patterns. In some cases, the symbol may be omitted. Also, the same symbol may be used in places with similar functions. A note is added, and a detailed explanation may be omitted.

[0127] <Example of light-emitting element configuration 1> Figure 2(A) is a schematic cross-sectional view of the light-emitting element 260.

[0128] The light-emitting element 260 shown in Figure 2(A) has a pair of electrodes (electrode 101 and electrode 102) between them. , multiple light-emitting units (in Figure 2(A), light-emitting unit 106 and light-emitting unit 1 08) has. One light-emitting unit has a configuration similar to the EL layer 100 shown in Figure 1(A). It has. In other words, the light-emitting element 250 shown in Figure 1(A) has one light-emitting unit and emits The optical element 260 has multiple light-emitting units. In the light-emitting element 260, electrode 1 Assuming that electrode 01 functions as the anode and electrode 102 functions as the cathode, the following explanation will be given, The configuration of the optical element 260 can be reversed.

[0129] Furthermore, in the light-emitting element 260 shown in Figure 2(A), the light-emitting unit 106 and the light-emitting unit 108 is stacked, and between the light-emitting unit 106 and the light-emitting unit 108 there is an electric current A bio-layer 115 is provided. Note that the light-emitting unit 106 and the light-emitting unit 108 have the same configuration. However, a different configuration is also acceptable. For example, the light-emitting unit 108 may have the EL layer 10 shown in Figure 1(A) Using 0 is preferable.

[0130] Furthermore, the light-emitting element 260 has a light-emitting layer 120 and a light-emitting layer 130. In addition to the light-emitting layer 120, knit 106 also includes a hole injection layer 111, a hole transport layer 112, and an electron transport layer. It has a layer 113 and an electron injection layer 114. The light-emitting unit 108 also has a light-emitting layer 130 In addition, there is a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0131] The charge generation layer 115 is a hole transport material to which an acceptor substance, which is an electron acceptor, is added. Even with such a configuration, the electron transport material is combined with a donor substance that acts as an electron donor. This is also acceptable. Furthermore, both of these configurations may be stacked.

[0132] If the charge generation layer 115 contains a composite material of an organic compound and an acceptor substance, The composite material used is a composite material that can be used in the hole injection layer 111 shown in Embodiment 1. That's all. As for organic compounds, aromatic amine compounds, carbazole compounds, aromatic carbon compounds Various compounds are used, such as hydrogen and polymer compounds (oligomers, dendrimers, polymers, etc.). It can exist. Furthermore, as an organic compound, its hole mobility is 1 × 10⁻⁶. -6 cm 2 / Vs It is preferable to use a material that meets the above criteria. However, a material that has higher hole transport than electron transport. In that case, other substances may be used. Composite materials of organic compounds and acceptor substances. Because the material has excellent carrier injection and carrier transport properties, it enables low-voltage and low-current operation. It can be displayed. Furthermore, as with the light-emitting unit 108, the anode side surface of the light-emitting unit is If in contact with the charge generation layer 115, the charge generation layer 115 is connected to the hole injection layer of the light-emitting unit. Since it can also serve as a hole transport layer, the light-emitting unit has a hole injection layer or a hole transport layer. It is not necessary to provide a pore transport layer.

[0133] Furthermore, the charge generation layer 115 is a layer containing a composite material of an organic compound and an acceptor substance, and other It may be formed as a laminated structure by combining layers made of the following materials. For example, organic A layer containing a composite material of a compound and an acceptor substance, and one selected from among electron-donating substances. A layer containing the compound and a compound with high electron transport properties may be formed by combining them. A layer containing a composite material of an organic compound and an acceptor substance, and a layer containing a transparent conductive material are combined. They may be formed by combining them.

[0134] Furthermore, the charge generation layer 115 sandwiched between the light-emitting unit 106 and the light-emitting unit 108 is electric When a voltage is applied to electrode 101 and electrode 102, electrons are injected into one of the light-emitting units. Any method that injects holes into the other light-emitting unit is acceptable. For example, in Figure 2(A), When a voltage is applied such that the potential of electrode 101 is higher than the potential of electrode 102, The charge generation layer 115 injects electrons into the light-emitting unit 106 and holes into the light-emitting unit 108. Enter.

[0135] Furthermore, the charge generation layer 115 has light transmission to visible light (specifically) from the viewpoint of light extraction efficiency. It is preferable that the charge generation layer 115 has a visible light transmittance of 40% or more. Furthermore, the charge generation layer 115 has lower conductivity than the pair of electrodes (electrode 101 and electrode 102). It will still function. If the conductivity of the charge generation layer 115 is as high as that of the pair of electrodes, the charge The carriers generated by the generation layer 115 flow in the direction of the film surface, causing the electrodes 101 and the electrodes to flow together. In some cases, light emission may occur in areas that do not overlap with 102. This defect can be suppressed. For this purpose, the charge generation layer 115 is preferably formed of a material with lower conductivity than the pair of electrodes. It's nice.

[0136] By forming the charge generation layer 115 using the materials described above, the light-emitting layer is stacked in the field This can suppress the rise in drive voltage during operation.

[0137] Furthermore, Figure 2(A) illustrates a light-emitting element having two light-emitting units. However, the same principle can also be applied to light-emitting devices that have three or more light-emitting units stacked on top of each other. As shown in the light-emitting element 260, multiple light-emitting units are placed between a pair of electrodes in a charge generation layer. By partitioning and arranging the elements, high-brightness light emission is possible while maintaining a low current density, and further This enables the creation of light-emitting elements with a long lifespan. Furthermore, it enables the creation of light-emitting elements with low power consumption. .

[0138] Furthermore, of the multiple units, at least one unit has the EL layer shown in Figure 1(A). By applying the 100 configuration, it is possible to provide a light-emitting element with high luminescence efficiency. ru.

[0139] Furthermore, the light-emitting layer 130 of the light-emitting unit 108 has the configuration shown in Embodiment 1. It is preferable that the light-emitting element 260 has a fluorescent material as the light-emitting material and This is preferable as it becomes a light-emitting element with high luminescence efficiency.

[0140] Furthermore, the light-emitting layer 120 of the light-emitting unit 108 is, as shown in Figure 2(B), host The apparatus comprises material 121 and guest material 122. The guest material 122 is a fluorescent material. The following explains this.

[0141] ≪Light-emitting mechanism of light-emitting layer 120≫ The light-emitting mechanism of the light-emitting layer 120 will be explained below.

[0142] Electrons injected from a pair of electrodes (electrode 101 and electrode 102) or a charge generation layer Excitons are generated when holes recombine in the light-emitting layer 120. Guest material 1 Since there is a large amount of host material 121 compared to 22, the host material is generated by exciton production. An excited state of material 121 is formed.

[0143] An exciton is a carrier (electron and hole) pair. An exciton has energy. Therefore, the material from which excitons are generated enters an excited state.

[0144] If the excited state of the formed host material 121 is a singlet excited state, then the host material 12 Singlet excitation energy is transferred from the S1 level of material 1 to the S1 level of guest material 122. Then, a singlet excited state is formed in guest material 122.

[0145] Since guest material 122 is a fluorescent material, the singlet excited state in guest material 122 Once formed, the guest material 122 rapidly emits light. At this time, to obtain high luminescence efficiency... Therefore, it is preferable that the fluorescence quantum yield of guest material 122 is high. The same applies in case 2, when carriers recombine and the resulting excited state is a singlet excited state. That is the case.

[0146] Next, when a triplet excited state of the host material 121 is formed by carrier recombination... This will be explained. The energy levels of the host material 121 and guest material 122 in this case. The correlation of the positions is shown in Figure 2(C). The notation and symbols in Figure 2(C) are as follows: Furthermore, the T1 level of the host material 121 is lower than the T1 level of the guest material 122. Since this is preferable, Figure 2(C) illustrates this case, but the T1 level of the host material 121 This may be higher than the T1 level of guest material 122.

[0147] • Host(121): Host material 121 • Guest (122): Guest material 122 (fluorescent material) ·S FH : S1 level of host material 121 ·T FH :T1 level of host material 121 ·S FG : S1 level of guest material 122 (fluorescent material) ·T FG : T1 level of guest material 122 (fluorescent material)

[0148] As shown in Figure 2(C), triplet-triplet annihilation (TTA: triplet-triplet annihilation) Triplets generated by carrier recombination (et annihilation) When excitons come into close proximity, one of them reaches the S1 level (S) of the host material 121. FH ) energy A reaction occurs that converts the exciton into a singlet exciton with energy (see Figure 2(C) TTA). The singlet excitation energy of material 121 is S FH Therefore, a lower energy S1 level of material 122 (S FG Energy transfer occurs to (Figure 2(C) Route E1) (See reference) A singlet excited state is formed in guest material 122, and guest material 122 emits light.

[0149] Furthermore, if the density of triplet excitons in the light-emitting layer 120 is sufficiently high (for example, 1 × 10⁻⁶ - 12 cm -3 In the above (case), the deactivation of singlet triplet excitons is ignored, and only the reaction by two adjacent triplet excitons can be considered.

[0150] Also, when carriers recombine in the guest material 122 to form a triplet excited state, since the triplet excited state of the guest material 122 thermally deactivates, it becomes difficult to utilize it for luminescence. However, when the T1 level (T FH ) of the host material 121 is lower than the T1 level (T ) of the guest material 122, the triplet excitation energy of the guest material 122 can be energy - transferred FG from the T1 level (T ) of the guest material 122 to the T1 level (T FG ) of the host material 121 (see Route E2 in Fig. 2(C)), and then it is utilized for TTA. FH That is, it is preferable that the host material 121 has a function of converting triplet excitation energy into singlet excitation energy by TTA. By doing so, a part of the triplet excitation energy generated in the light - emitting layer 120 is converted into singlet excitation energy by TTA in the host material 121, and the singlet excitation energy is transferred to the guest material 122, so that fluorescence emission can be extracted. For this purpose, it is preferable that the S1 level (S

[0151] FH ) of the host material 121 is higher than the S1 level (S ) of the guest material 122. Also, it is preferable that the T1 level (T ) of the host material 121 is lower than the T1 level (T ) of the guest material 122. FH ) of the host material 121 is higher than the S1 level (S FG ) of the guest material 122. Also, it is preferable that the T1 level (T FH ) of the host material 121 is lower than the T1 level (T FG ) of the guest material 122. FG

[0152] Note that especially for the T1 level (T​​​FG ) is the T1 level (T FH If it is lower than ), the weight ratio of host material 121 to guest material 122 is, A lower weight ratio of guest material 122 is preferable. Specifically, a lower weight ratio of the guest material 122 relative to the host material 121. The weight ratio of guest material 122 is preferably greater than 0 and 0.05 or less. The probability of carrier recombination can be reduced with guest material 122. T1 level of material 121 (T FH ) from guest material 122 T1 level (T FG ) energy This can reduce the probability of ghee movement occurring.

[0153] The host material 121 may be composed of a single compound, or it may be composed of multiple compounds. It's fine if it's done.

[0154] In addition, in each of the above configurations, the luminescent unit 106 and the luminescent unit 108 are used The fluorescent material may be the same or different. Light-emitting unit 10 If the light-emitting unit 108 and 6 have the same guest material, the light-emitting element 260 will have a lower current. It is preferable to have a light-emitting element that exhibits high luminous brightness at a given value. When knit 108 has a different guest material, the light-emitting element 260 exhibits multicolor emission. It is preferable to use it as an optical element. In particular, it emits white light with high color rendering, or at least red and green light. It is preferable to select guest materials such that they emit light that has a blue color.

[0155] <Example of light-emitting element configuration 2> Figure 3(A) is a schematic cross-sectional view of the light-emitting element 262.

[0156] The light-emitting element 262 shown in Figure 3(A) is similar to the light-emitting element 260 shown earlier, and consists of a pair of electrodes. Between electrodes 101 and 102, there are multiple light-emitting units (in Figure 3(A), It has a light unit 106 and a light-emitting unit 108). One light-emitting unit is shown in Figure 1(A It has a similar configuration to the EL layer 100 shown in ). Note that the light-emitting unit 106 and the light-emitting unit 108 can have the same configuration or a different configuration.

[0157] Furthermore, in the light-emitting element 262 shown in Figure 3(A), the light-emitting unit 106 and the light-emitting unit 108 is stacked, and between the light-emitting unit 106 and the light-emitting unit 108 there is an electric current A raw layer 115 is provided. For example, the light-emitting unit 106 has an EL layer 10 as shown in Figure 1(A). Using 0 is preferable.

[0158] Furthermore, the light-emitting element 262 has a light-emitting layer 130 and a light-emitting layer 140. In addition to the light-emitting layer 130, knit 106 also includes a hole injection layer 111, a hole transport layer 112, and an electron transport layer. It has a layer 113 and an electron injection layer 114. The light-emitting unit 108 also has a light-emitting layer 140 In addition, there is a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0159] Furthermore, it is preferable that the light-emitting layer of the light-emitting unit 108 has a phosphorescent material. The light-emitting layer 130 of unit 106 has the configuration shown in Embodiment 1, and the light-emitting unit The light-emitting layer 140 of T108 preferably has a phosphorescent material. The 262 configuration examples will be explained below.

[0160] Furthermore, the light-emitting layer 140 of the light-emitting unit 108 is, as shown in Figure 3(B), host It has a host material 141 and a guest material 142. The host material 141 has an organic compound 1 41_1 and an organic compound 141_2. The guest material 142 in the light-emitting layer 140 is a phosphorescent material, which will be described below.

[0161] ≪Light-emitting mechanism of the light-emitting layer 140≫ Next, the light-emitting mechanism of the light-emitting layer 140 will be described below.

[0162] The organic compound 141_1 and the organic compound 141_2 in the light-emitting layer 140 form an exciplex. ..

[0163] The combination of the organic compound 141_1 and the organic compound 141_2 that form an exciplex in the light-emitting layer 140 may be any combination capable of forming an exciplex, but it is more preferable that one is a compound having hole-transporting properties and the other is a compound having electron-transporting properties.

[0164] The correlation of the energy levels among the organic compound 141_1, the organic compound 141_2, and the guest material 142 in the light-emitting layer 140 is shown in Fig. 3(C). The notations and symbols in Fig. 3(C) are as follows. ·Host(141_1): Organic compound 141_1 (host material) ·Host(141_2): Organic compound 141_2 (host material) ·Guest(142): Guest material 142 (phosphorescent material) ·S PH : S1 level of the organic compound 141_1 (host material) ·T PH : T1 level of the organic compound 141_1 (host material) [[ID=5L]]·T PG : T1 level of the guest material 142 (phosphorescent material) ·S PE : S1 level of the exciplex​​​​​​ ·T PE : T1 level of the excited complex

[0165] A singlet excited complex formed by organic compound 141_1 and organic compound 141_2. The lowest level of the excited state (S PE ) and the lowest level of the triplet excited state of the excited complex (T PE ) will be adjacent to each other (see Figure 3(C) Route C).

[0166] And the excited complex (S PE ) and (T PE The energy of both ) is used by guest material 142 Light emission is obtained by shifting to the lowest level of the triplet excited state of the (phosphorescent material) (Figure 3(C)). (See Route D).

[0167] Furthermore, the processes of Route C and Route D described above are referred to in this specification, etc. as E It is called xTET (Exciplex-Triplet Energy Transfer). It may be referred to as such.

[0168] Furthermore, organic compound 141_1 and organic compound 141_2 have holes in one and electrons in the other. It forms an excited complex by accepting a particle. Alternatively, when one becomes excited, it interacts with the other. They form an excited complex through interaction. Therefore, most of the excitons in the light-emitting layer 140 Most exist as excited complexes. The excited complexes are organic compound 141_1 and organic compound 14 Since the band gap is smaller than in both 1 and 2, excitation occurs at a lower excitation energy. This makes it possible to form a state. Therefore, by forming an excited complex, the luminescent element The drive voltage of the child can be reduced.

[0169] By configuring the light-emitting layer 140 as described above, the guest material 142 (phosphorescent material) of the light-emitting layer 140 This makes it possible to efficiently obtain light emission from ).

[0170] Furthermore, the emission from the light-emitting layer 130 has a shorter wavelength peak than the emission from the light-emitting layer 140. It is preferable to have a configuration that has a luminescent element. The child tends to experience rapid brightness degradation. Therefore, by using fluorescence emission for short-wavelength emission, This makes it possible to provide a light-emitting element with minimal brightness degradation.

[0171] Furthermore, by obtaining light of different emission wavelengths from the light-emitting layer 130 and the light-emitting layer 140, multicolor It can be used as a light-emitting element. In this case, the emission spectrum will have different emission peaks. Since the emitted light is a composite of light, the emission spectrum will have at least two maxima. .

[0172] Furthermore, the above configuration is also suitable for obtaining white light emission. Light-emitting layer 130 and light-emitting layer 140 By making the light and the light complementary to each other, white light emission can be obtained.

[0173] Furthermore, one or both of the light-emitting layers 130 and 140 may have multiple emission wavelengths. By using multiple light-emitting materials, it is possible to produce highly color-rendering colors consisting of the three primary colors or four or more light-emitting colors. White light emission can also be obtained. In this case, either the light-emitting layer 130 or the light-emitting layer 140 Alternatively, both can be further divided into layers, and each divided layer can contain a different light-emitting material. You can do that too.

[0174] <Examples of materials that can be used for the light-emitting layer> Next, regarding the materials that can be used for the light-emitting layer 120, light-emitting layer 130, and light-emitting layer 140... I will explain below.

[0175] <<Materials that can be used for the light-emitting layer 130>> Materials that can be used for the light-emitting layer 130 include the light-emitting layer 13 shown in Embodiment 1 above. You can use materials that can be used for 0. By doing so, you can generate singlet excited states. It is possible to fabricate light-emitting devices with high efficiency and high luminous efficiency.

[0176] <<Materials that can be used for the light-emitting layer 120>> In the light-emitting layer 120, the host material 121 is the most abundant by weight, followed by the guest material 122 The (fluorescent material) is dispersed in the host material 121. The S1 level of the host material 121 is The T1 level of host material 121 is higher than the S1 level of host material 122 (fluorescent material), It is preferable that the level is lower than the T1 level of the fluorescent material 122.

[0177] In the light-emitting layer 120, there are no particular limitations on the guest material 122, but for example, The material exemplified as guest material 132 shown in Embodiment 1 can be used.

[0178] Furthermore, in the light-emitting layer 120, the materials that can be used for the host material 121 are: There are no particular limitations, but for example, tris(8-quinolinolato)aluminum(III) (abbreviation) :Alq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) Abbreviation: BeBq2), bis(2-methyl-8-quinolinolate)(4-phenylphenolate ) Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (Abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolate]zinc(II) Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) Metal complexes such as (abbreviated as ZnBTZ), 2-(4-biphenylyl)-5-(4-tert- Butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5 -(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]ben Zen (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-te rt-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2' -(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimidazo Vasophenanthroline (abbreviation: TPBI), Vasophenanthroline (abbreviation: BPhen), Vasocuproline (Abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1 ,10-Phenanthroline (abbreviation: NBPhen), 9-[4-(5-phenyl-1,3 ,4-Oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11 ) such heterocyclic compounds, 4,4'-bis[N-(1-naphthyl)-N-phenylamino] Biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methylphenyl) -N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TP) D) 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-fe Examples include aromatic amine compounds such as [nylaminobiphenyl] (abbreviated as BSPB). Anthracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, gibel Examples include condensed polycyclic aromatic compounds such as nzzo[g,p]chrysene derivatives, specifically, 9, 10-Diphenylanthracene (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), 4-(9H-carbazol-9-yl)-4'-(10-phenyl -9-Anthlyl)triphenylamine (abbreviation: YGAPA), N,9-diphenyl-N -[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole-3-a Min (abbreviation: PCAPA), N,9-diphenyl-N-{4-[4-(10-phenyl- 9-Anthryl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PC) APBA), N,9-diphenyl-N-(9,10-diphenyl-2-anthryl)-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), 9-[4-(10-phenyl-9-antryl)phenyl]-9H-cal Bazol (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9- Anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 9,10-bis (3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2- Naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2- Naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-bianthryl (abbreviation: B ANT), 9,9'-(stilben-3,3'-diyl)diphenanthrene (abbreviation: DP) NS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviation: DPN) Examples include S2, 1,3,5-tri(1-pyrenyl)benzene (abbreviated as TPB3), etc. This can be done. Also, from among these and known substances, the energy of the above guest material 122 Select one or more materials that have an energy gap larger than the gap and use them. Just be there.

[0179] The light-emitting layer 120 can also be composed of two or more layers. For example, the first When the first light-emitting layer and the second light-emitting layer are stacked in order from the hole transport layer side to form the light-emitting layer 120, A material having hole transport properties is used as the host material for the first light-emitting layer, and the host material for the second light-emitting layer One such configuration involves using materials that possess electron-transporting properties.

[0180] Furthermore, in the light-emitting layer 120, the host material 121 is composed of a certain compound. It is also fine if it is composed of multiple compounds. Alternatively, in the light-emitting layer 120, It may also contain materials other than stock material 121 and guest material 122.

[0181] <<Materials that can be used for the light-emitting layer 140>> In the light-emitting layer 140, the host material 141 is the most abundant by weight, followed by the guest material 142 The (phosphorescent material) is dispersed in the host material 141. Host material 141 of the light-emitting layer 140 ( The T1 levels of organic compounds 141_1 and 141_2 are guest levels of the luminescent layer 140. It is preferable that the T1 level is higher than that of the material (guest material 142).

[0182] Organic compound 141_1 includes zinc and aluminum-based metal complexes, as well as oxadiazo Diazepam derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, diazepam Dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidin phenanthroline derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives Examples include conductors. Other examples include aromatic amines and carbazole derivatives. Specifically, using the electron-transporting material and hole-transporting material shown in Embodiment 1, It is possible.

[0183] Organic compound 141_2 is a combination that can form an excited complex with organic compound 141_1. A combination is preferred. Specifically, the electron transport material and hole transport material shown in Embodiment 1. In this case, organic compound 141_1 and organic compound 141_2 can be used. The emission peak of the excited complex formed is the triplet MLCT of guest material 142 (phosphorescent material) The absorption band of the Metal to Light Charge Transfer transition, Specifically, organic compound 141_1 and organic compound 141_1 are positioned so as to overlap with the absorption band on the longest wavelength side. It is preferable to select material 141_2 and guest material 142 (phosphorescent material). This allows for the creation of a light-emitting element with dramatically improved luminescence efficiency. However, if the phosphorescent material is replaced... Furthermore, when using thermally activated delayed fluorescence materials, the absorption band on the longest wavelength side is singlet absorption. It is preferable that it be a cascading area.

[0184] Guest material 142 (phosphorescent material) can be iridium, rhodium, or platinum-based organic Examples include metal complexes, or metal complexes in particular, organoiridium complexes, such as iridium Orthometallic complexes are preferred. 4H-triazole is a suitable ligand for orthometallation. Ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidines Examples include ligands, pyrazine ligands, or isoquinoline ligands. Examples include platinum complexes having porphyrin ligands.

[0185] Examples of substances that have a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo [Ir-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir(mpp) tz-dmp)3), Tris(5-methyl-3,4-diphenyl-4H-1,2,4-) Ryasolato) Iridium(III) (abbreviation: Ir(Mptz)3), Tris[4-(3- [Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato] Lydium(III) (abbreviation: Ir(iPrptz-3b)3), Tris[3-(5-Bif [Phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridi A 4H-triazole skeleton like Um(III) (abbreviation: Ir(iPr5btz)3) The organometallic iridium complex and tris[3-methyl-1-(2-methylphenyl)- 5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir( Mptz1-mp)3), Tris(1-methyl-5-phenyl-3-propyl-1H-1 ,2,4-Triazolat) Iridium(III) (abbreviation: Ir(Prptz1-Me)3 ) Organometallic iridium complexes having a 1H-triazole skeleton, such as fac-tris [1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole] Dium(III) (abbreviation: Ir(iPrpmi)3), Tris[3-(2,6-dimethyl] Phenyl)-7-methylimidazo[1,2-f]phenantridinato]iridium(II Organic compounds having an imidazole skeleton, such as I) (abbreviation: Ir(dmpimpt-Me)3) Metallic iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinate-N ,C 2’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation: Fir 6) Bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ Iridi Um(III) picolinate (abbreviation: Firpic), bis{2-[3',5'-bis( Trifluoromethyl)phenyl]pyridinate-N,C 2’ Iridium(III) picoli Naat (abbreviation: Ir(CF3ppy)2(pic)), Bis[2-(4',6'-jiful Olophenyl)pyridinato-N,C 2’ Iridium(III) acetylacetonate ( A phenylpyridine derivative having an electron-withdrawing group, such as the abbreviation FIr(acac)), is coordinated. Examples of its derivatives include organometallic iridium complexes. Among those mentioned above, 4H-triazole bone Organometallic iridium complexes with a specific grade are particularly preferred due to their excellent reliability and luminescence efficiency.

[0186] Furthermore, examples of substances that have a green or yellow emission peak include tris(4-methyl Iridium(III) (abbreviation: Ir(mppm)3), 6-phenylpyrimidinato Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm)3), (acetylacetonate)bis(6-methyl-4-phenylpyryl) Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetyl Luacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium III) (Abbreviation: Ir(tBuppm)2(acac)), (acetylacetonato)bis [4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation) :Ir(nbppm)2(acac)),(acetylacetonato)bis[5-methyl-6 -(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis{4,6-dimethicone} Lu-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl- κC} Iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), ( Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Abbreviation: Organometallic irritants with a pyrimidine skeleton, such as Ir(dppm)2(acac) Dium complexes, and (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetyl Luacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridi Pyrazine bones like Um(III) (abbreviation: Ir(mppr-iPr)2(acac)) iridium organometallic complexes with a specific classification, and tris(2-phenylpyridinato-N,C) 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinate-N) ,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(ac) ac)), bis(benzo[h]quinolinate)iridium(III)acetylacetonate (Abbreviation: Ir(bzq)2(acac)), Tris(benzo[h]quinolinato)iridiu Mu(III) (abbreviation: Ir(bzq)3), Tris(2-phenylquinolinato-N,C) 2 ’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinolinazole- N,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(pq)2(ac) Organometallic iridium complexes having a pyridine skeleton, such as ac)), and bis(2,4-diph Enyl-1,3-oxazolato-N,C 2’ Iridium(III) Acetylaceton (abbreviation: Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenicol) [Phenyl]pyridinate-N,C 2’ Iridium(III) acetylacetonate ( Abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazolat -N,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(a) In addition to organometallic iridium complexes such as CAC, there are also tris(acetylacetonate)(monophenate). Nanthroline terbium(III) (abbreviation: Tb(acac)3(Phen)) Examples include rare earth metal complexes. Among those mentioned above, organometallic ylids having a pyrimidine skeleton are particularly noteworthy. Dium complexes are particularly preferred because they exhibit outstanding reliability and luminescence efficiency.

[0187] Furthermore, examples of substances that have a yellow or red emission peak include (diisobutyryl Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II) I) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methyl [Phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5 mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl)pyrimid Nat] (dipivaloylmethanato) Iridium(III) (Abbreviation: Ir(d1npm)2) Organometallic iridium complexes having a pyrimidine skeleton such as dpm, and (acetylacet Tonato)bis(2,3,5-triphenylpyradinato)iridium(III) (abbreviation: I r(tppr)2(acac)), bis(2,3,5-triphenylpyrazinate)(dipy Valoylmethanato) Iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato] Pyrazine bones like lysium(III) (abbreviation: [Ir(Fdpq)2(acac)]) iridium organometallic complexes with a specific classification, and tris(1-phenylisoquinolinato-N,C) 2 ’ Iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinol) Nato-N,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(piq)) In addition to organometallic iridium complexes having a pyridine skeleton like 2(acac)), 2,3, 7,8,12,13,17,18-Octaethyl-21H,23H-Porphyrin Platinum ( Platinum complexes such as (II) (abbreviation: PtOEP), and tris(1,3-diphenyl-1,3) -Propanedionato) (monophenanthroline) europium(III) (abbreviation: Eu( DBM)3(Phen)), Tris[1-(2-tenoyl)-3,3,3-trifluoro [Acetonato](monophenanthroline) europium(III) (abbreviation: Eu(TTA)) Examples include rare earth metal complexes such as 3(Phen)). Among those mentioned above, pyrimidine bone Organometallic iridium complexes with a specific rating are particularly favored due to their outstanding reliability and luminescence efficiency. Furthermore, organometallic iridium complexes with a pyrazine skeleton exhibit good coloration red luminescence. It can be obtained.

[0188] The light-emitting material included in the light-emitting layer 140 is capable of converting triplet excitation energy into light emission. Any material will do. A material that can convert the triplet excitation energy into light emission is a phosphorescent material. In addition, there is thermally activated delayed fluorescence. Examples include fluorescence (TADF) materials. Therefore, phosphorescent materials are also mentioned. The section provided can be interpreted as referring to thermally activated delayed fluorescence materials. Delayed fluorescence materials are those in which the difference between the triplet excitation energy level and the singlet excitation energy level is small. Furthermore, it has the function of converting energy from a triplet excited state to a singlet excited state through reverse intersystem crossing. It is a material that possesses the following properties. Therefore, the triplet excited state is converted to a singlet state with only a small amount of thermal energy. Upconversion to the excited state (reverse intersystem crossing) is possible, and emission (fluorescence) from the singlet excited state is possible. ) can be efficiently exhibited. Furthermore, the conditions under which thermally activated delayed fluorescence can be efficiently obtained are Therefore, the energy difference between the triplet excitation energy level and the singlet excitation energy level is preferable. It is greater than 0 eV and less than or equal to 0.2 eV, and more preferably greater than 0 eV and less than or equal to 0.1 eV. One example is that...

[0189] Furthermore, materials exhibiting thermally activated delayed fluorescence can be obtained by reverse intersystem crossing from a triplet excited state on their own. It may be a material capable of generating a multiplet excited state, or an excited complex (excyplex, also It may be composed of multiple materials that form an Exciplex (also known as an Exciplex).

[0190] When a thermally activated delayed fluorescence material is composed of one type of material, specifically, in the embodiment The thermally activated delayed fluorescence material shown in 1 can be used.

[0191] Furthermore, when using a thermally activated delayed fluorescence material as a host material, two types of excitation complexes are formed. It is preferable to use a combination of compounds of the same type. In this case, the excitation complex shown above is formed The combinations that make up the combination are compounds that readily accept electrons and compounds that readily accept holes. It is particularly preferable to use [this].

[0192] Furthermore, the emission color of the light-emitting material contained in the light-emitting layer 120, light-emitting layer 130, and light-emitting layer 140 There are no limitations; they can be the same or different. The light emitted from each is mixed. Since it is extracted outside the element, for example, if the light emitted by both is complementary to each other, the light-emitting element The child can emit white light. Considering the reliability of the light-emitting element, the light-emitting layer 120 is included The emission peak wavelength of the light-emitting material is shorter than that of the light-emitting material contained in the light-emitting layer 140. This is preferable.

[0193] Furthermore, the light-emitting unit 106, the light-emitting unit 108, and the charge generation layer 115 are produced by a vapor deposition method. Formed by methods such as vacuum deposition, inkjet printing, coating, and gravure printing. It is possible.

[0194] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there.

[0195] (Embodiment 3) In this embodiment, the light-emitting element has a configuration different from that shown in Embodiments 1 and 2. An example of this will be explained below using Figures 4 to 7.

[0196] <Example of light-emitting element configuration 1> Figures 4(A) and 4(B) are cross-sectional views showing a light-emitting element according to one embodiment of the present invention. In (B), the same hatching is used in areas that have the same function as the symbols shown in Figure 1(A). In some cases, the code may be omitted as a pattern. Also, similar functions are used in similar places. Symbols may be used, and detailed explanations may be omitted.

[0197] The light-emitting elements 270a and 270b shown in Figures 4(A) and 4(B) are connected to the substrate 200 side. It may also be a bottom-emission type light-emitting element that extracts from the substrate 200 and It may also be a top-emission type light-emitting element that extracts light in the opposite direction. However, one aspect of the present invention is not limited thereto, and the light emitted by the light-emitting element is directed above the substrate 200. It may also be a dual-emission type light-emitting element that emits light from both the upper and lower sides. .

[0198] When the light-emitting element 270a and the light-emitting element 270b are of the bottom emission type, electrode 1 Preferably, 01 has the function of transmitting light. Also, electrode 102 reflects light. It is preferable that the light-emitting element 270a and the light-emitting element 270b have a function. In the case of a top-emission type, it is preferable that the electrode 101 has the function of reflecting light. Furthermore, it is preferable that the electrode 102 has the function of transmitting light.

[0199] The light-emitting element 270a and the light-emitting element 270b have an electrode 101 and an electrode 102 on the substrate 200. It has the following: In addition, between electrode 101 and electrode 102, there is a light-emitting layer 123B and a light-emitting layer 123 It has G and a light-emitting layer 123R. It also has a hole injection layer 111 and a hole transport layer 112. It has an electron transport layer 118 and an electron injection layer 119.

[0200] Furthermore, the light-emitting element 270b is part of the configuration of the electrode 101, and the conductive layer 101a and It has a conductive layer 101b on layer 101a and a conductive layer 101c below the conductive layer 101a. In other words, the light-emitting element 270b has a conductive layer 101a, a conductive layer 101b, and a conductive layer 101c. It has a configuration of clamped electrodes 101.

[0201] In the light-emitting element 270b, the conductive layer 101b and the conductive layer 101c are made of different materials. It may be done in this way, or it may be formed from the same material. The electrode 101 may be sandwiched between the same conductive material. Having such a configuration is preferable because it facilitates pattern formation through the etching process.

[0202] Furthermore, in the light-emitting element 270b, in the conductive layer 101b or the conductive layer 101c, A configuration having only one of the two offsets is also acceptable.

[0203] Furthermore, the conductive layers 101a, 101b, and 101c of the electrode 101 are each actual Using the same configuration and materials as electrode 101 or electrode 102 shown in Method 1 of the application can.

[0204] In Figures 4(A) and 4(B), the region 221B is sandwiched between electrode 101 and electrode 102. A partition wall 145 is located between region 221G and region 221R. The partition wall 145 provides insulation. The partition wall 145 covers the end of the electrode 101 and has an opening that overlaps with the electrode. By providing the wall 145, the electrodes 101 on the substrate 200 in each region are arranged in island-like formations. It becomes possible to separate them.

[0205] Furthermore, in the region where the light-emitting layer 123B and the light-emitting layer 123G overlap with the partition wall 145, They may have overlapping regions. Also, the light-emitting layer 123G and the light-emitting layer 123R are In the region that overlaps with the partition wall 145, there may be overlapping regions. In the region where layer 123R and the light-emitting layer 123B overlap with the partition wall 145, they overlap each other. It may have a domain.

[0206] The partition wall 145 only needs to be insulating and is formed using an inorganic or organic material. The inorganic materials include silicon oxide, silicon oxide nitride, silicon nitride oxide, silicon nitride silicon Examples of organic materials include aluminum oxide, aluminum nitride, etc. Examples include photosensitive resin materials such as acrylic resin or polyimide resin.

[0207] Furthermore, the light-emitting layer 123R, light-emitting layer 123G, and light-emitting layer 123B each exhibit different colors. It is preferable to have a light-emitting material that has the function of emitting red light. For example, the light-emitting layer 123R exhibits red light. By having a light-emitting material that has the function of, region 221R exhibits red light emission, and light-emitting layer 12 Region 221G emits green light because region 3G has a light-emitting material that exhibits a green light. The light-emitting layer 123B has a light-emitting material that exhibits a blue color, thus region 221 B emits blue light. A light-emitting element 270a or light-emitting element 27 has such a configuration. By using 0b as the pixel of the display device, a display device capable of full-color display can be manufactured. This is possible. Also, the film thickness of each light-emitting layer may be the same or different. good.

[0208] Additionally, one or more of the light-emitting layers 123B, 123G, and 123R. The light-emitting layer preferably has the light-emitting layer 130 shown in Embodiment 1. This allows for the fabrication of light-emitting elements with good luminescence efficiency.

[0209] Note that one or more of the light-emitting layers 123B, 123G, and 123R may be present. The light-emitting layer may be configured with two or more layers stacked on top of each other.

[0210] As described above, at least one light-emitting layer has the light-emitting layer shown in Embodiment 1, and the light emission By using a layered light-emitting element 270a or light-emitting element 270b as a pixel of a display device, This makes it possible to fabricate a display device with high luminous efficiency. That is, the light-emitting element 270a or A display device having a light-emitting element 270b can reduce power consumption.

[0211] Furthermore, by providing a color filter on the electrode that extracts light, the light-emitting element 270a and The color purity of the light-emitting element 270b can be improved. Therefore, the light-emitting element 270a and This can improve the color purity of a display device having a light-emitting element 270b.

[0212] Furthermore, by providing a polarizing plate on the electrode that extracts light, the light-emitting element 270a and the light-emitting element are provided. External light reflection of 270b can be reduced. Therefore, the light-emitting element 270a or light-emitting element The contrast ratio of a display device having sub-element 270b can be increased.

[0213] Furthermore, other configurations of the light-emitting element 270a and light-emitting element 270b are as follows: You should consider the configuration of the light-emitting element in state 1.

[0214] <Example of light-emitting element configuration 2> Next, using Figures 5(A) and 5(B), we will discuss a configuration example different from the light-emitting element shown in Figure 4. Give an explanation.

[0215] Figures 5(A) and 5(B) are cross-sectional views showing a light-emitting element according to one embodiment of the present invention. In (B), the same hatch pattern is used in the parts that have the same function as the symbols shown in Figure 4. The symbol may be omitted. Also, the same symbol is used in places with similar functions. Furthermore, detailed explanations may be omitted.

[0216] Figures 5(A) and 5(B) show examples of the configuration of a light-emitting element having a light-emitting layer between a pair of electrodes. The light-emitting element 272a shown in (A) is an upper-surface emitter that extracts light in the opposite direction to the substrate 200. The light-emitting element of the (up-emission) type, the light-emitting element 272b shown in Figure 5(B), is on the substrate 200 side. This is a bottom-emission type light-emitting element that extracts light from the bottom. One embodiment is not limited thereto, and the light emitted by the light-emitting element is on the substrate 200 on which the light-emitting element is formed. It may also be a dual-emission type that extracts material from both the front and the bottom.

[0217] The light-emitting element 272a and the light-emitting element 272b have an electrode 101 and an electrode 102 on the substrate 200. It has electrode 103 and electrode 104. Also, between electrode 101 and electrode 102, At least light is emitted between electrode 102 and electrode 103, and between electrode 102 and electrode 104. It has a layer 130 and a charge generation layer 115. It also has a hole injection layer 111 and a hole transport layer 11 2, the light-emitting layer 150, the electron transport layer 113, the electron injection layer 114, and the hole injection layer 116 It has a hole transport layer 117, an electron transport layer 118, and an electron injection layer 119.

[0218] Furthermore, the electrode 101 consists of a conductive layer 101a and a conductive layer 101b that is in contact with the conductive layer 101a. , has . Furthermore, electrode 103 has a conductive layer 103a and a conductive layer in contact with the conductive layer 103a 103b and Electrode 104 has a conductive layer 104a and a conductive layer in contact with the conductive layer 104a. It has an electrolytic layer 104b.

[0219] The light-emitting element 272a shown in Figure 5(A) and the light-emitting element 272b shown in Figure 5(B) are electrodes Region 222B sandwiched between electrode 101 and electrode 102, sandwiched between electrode 102 and electrode 103 Between region 222G and region 222R sandwiched between electrode 102 and electrode 104, It has a wall 145. The partition wall 145 is insulating. The partition wall 145 has electrodes 101 and 1 03, and the end of electrode 104 are covered, and the partition wall 145 has an opening that overlaps with the electrode. By doing so, the electrodes on the substrate 200 in each region can be separated into island-like structures. It becomes Noh.

[0220] Furthermore, the light-emitting element 272a and the light-emitting element 272b are located in region 222B, region 222G, and In the direction from which the light emitted from region 222R is extracted, the optical element 224B and the optical element are respectively positioned. The substrate 220 has a sub-element 224G and an optical element 224R. Light emitted from each region It is emitted to the outside of the light-emitting element through each optical element. That is, it is emitted from region 222B. The light is emitted through the optical element 224B, and the light emitted from region 222G is emitted through the optical element The light emitted through 224G and emanating from region 222R is transmitted through optical element 224R. It is launched.

[0221] Furthermore, optical elements 224B, 224G, and 224R receive incident light It has the function of selectively transmitting light exhibiting a specific color. For example, optical element 224B The light emitted from region 222B through the optical element 22 becomes blue light. The light emitted from region 222G via 4G becomes green light, and the optical element The light emitted from region 222R via sub-element 224R is red in color.

[0222] Optical elements 224R, 224G, and 224B include, for example, a colored layer ( Color filters (also called color filters), bandpass filters, and multilayer filters can be applied. Furthermore, a color conversion element can be applied to an optical element. The color conversion element converts the incident light to... This is an optical element that converts light to wavelengths longer than the wavelength of the light in question. It uses quantum dots as color conversion elements. It is preferable to use an element that employs quantum dots. By using quantum dots, the color reproducibility of the display device can be improved. It can improve.

[0223] Furthermore, multiple optical elements are placed on optical element 224R, optical element 224G, and optical element 224B. The child elements may be stacked. Other optical elements include, for example, circular polarizers and anti-reflective coatings. This can be done by placing a circular polarizing plate on the side from which the light emitted by the light-emitting element of the display device is extracted. Then, light entering from outside the display device is reflected inside the display device and emitted to the outside. This prevents the phenomenon of reflection from occurring. In addition, by providing an anti-reflective coating, reflection from the surface of the display device can be prevented. This allows for the reduction of ambient light, enabling clearer observation of the light emitted by the display device.

[0224] In Figures 5(A) and 5(B), the light emitted from each region through each optical element is referred to as blue. Let light exhibiting color (B), light exhibiting green (G), and light exhibiting red (R) be defined as follows: This is schematically illustrated with dashed arrows.

[0225] Furthermore, a light-shielding layer 223 is provided between each optical element. The light-shielding layer 223 is provided in adjacent regions or It has the function of blocking the light emitted from it. Furthermore, a configuration without the light-blocking layer 223 is also acceptable. stomach.

[0226] The light-shielding layer 223 has the function of suppressing the reflection of external light. Alternatively, the light-shielding layer 223 and Therefore, it has the function of preventing the mixing of colors of light emitted from adjacent light-emitting elements. Light-shielding layer 223 and For example, metals, resins containing black pigments, carbon black, metal oxides, and multiple metal oxides. A composite oxide containing a solid solution of a substance can be used.

[0227] Furthermore, the substrate 200 and the substrate 220 having optical elements should be considered in reference to Embodiment 1. That's all you need to do.

[0228] Furthermore, the light-emitting elements 272a and 272b have a microcavity structure. .

[0229] Light emitted from the light-emitting layer 130 and the light-emitting layer 150 is directed towards a pair of electrodes (for example, electrode 10 Resonance occurs between electrode 1 and electrode 102). Also, the light-emitting layer 130 and light-emitting layer 150 are emitted. It is formed at a position where the light of a desired wavelength is intensified among the incoming light. For example, in the reflection region of electrode 101 The optical distance from the light-emitting region of the light-emitting layer 130 to the optical distance from the reflection region of the electrode 102 to the light-emitting layer 130. By adjusting the optical distance to the light-emitting region, the light emitted from the light-emitting layer 130 can be controlled. This allows for the enhancement of light of a desired wavelength. Also, from the reflection region of electrode 101 to the light-emitting layer 150 The optical distance to the light-emitting region and the distance from the reflection region of electrode 102 to the light-emitting region of light-emitting layer 150 By adjusting the optical distance, the desired wavelength of light emitted from the light-emitting layer 150 can be selected. The light can be intensified. That is, multiple light-emitting layers (here, light-emitting layer 130 and light-emitting layer In the case of a light-emitting element that stacks 150), the optical distance between the light-emitting layer 130 and the light-emitting layer 150 is It is preferable to optimize the separation.

[0230] Furthermore, in the light-emitting element 272a and light-emitting element 272b, a conductive layer (conductive layer 1) is present in each region. By adjusting the thickness of 01b, conductive layer 103b, and conductive layer 104b), the light-emitting layer 130 Furthermore, it is possible to enhance the light of a desired wavelength from the light-emitting layer 150. In the region, at least one of the hole injection layer 111 and the hole transport layer 112 has a different thickness. This may enhance the light emitted from the light-emitting layer 130 and the light-emitting layer 150.

[0231] For example, electrodes 101 to 104 are made of a conductive material that has the function of reflecting light. When the refractive index is smaller than the refractive index of the light-emitting layer 130 or the light-emitting layer 150, the electrode The thickness of the conductive layer 101b on 101 is determined by the optical distance between electrode 101 and electrode 102 being m B λ B / 2(m B λ is a natural number, B (These represent the wavelengths of light that are strengthened in region 222B.) Adjust to achieve this. Similarly, the thickness of the conductive layer 103b on electrode 103 is adjusted to match electrode 103 and The optical distance between electrode 102 is m G λ G / 2(m G λ is a natural number, G Stronger in region 222G The wavelengths of light are adjusted to be (represented by). Furthermore, the conductive layer of electrode 104 The film thickness of 104b is such that the optical distance between electrode 104 and electrode 102 is m R λ R / 2(m R is natural number, λ R The wavelengths of light that are strengthened in region 222R are adjusted accordingly.

[0232] As described above, a microcavity structure is provided, and the optical distance between the pair of electrodes in each region is adjusted. By optimizing the surface, light scattering and absorption near each electrode are suppressed, resulting in a high light extraction efficiency. This can achieve a certain ratio. In the above configuration, conductive layer 101b, conductive layer 103 b. Preferably, the conductive layer 104b has the function of transmitting light. Also, conductive layer 101 The materials constituting b, conductive layer 103b, and conductive layer 104b may be the same as each other. They may be different. Also, conductive layer 101b, conductive layer 103b, conductive layer 104b are Each layer may have a configuration consisting of two or more layers stacked on top of each other.

[0233] Note that the light-emitting element 272a shown in Figure 5(A) is an upward-emitting type light-emitting element, and therefore is conductive Layer 101a, conductive layer 103a, and conductive layer 104a have the function of reflecting light. Preferably, the electrode 102 has both the function of transmitting light and the function of reflecting light. It is preferable.

[0234] Furthermore, the light-emitting element 272b shown in Figure 5(B) is a bottom-extrusion type light-emitting element, therefore it is conductive Layer 101a, conductive layer 103a, and conductive layer 104a have the function of transmitting light and the function of reflecting light. It is preferable that the electrode 102 has the ability to reflect light. preferable.

[0235] Furthermore, in the light-emitting element 272a and the light-emitting element 272b, conductive layer 101a, conductive layer 10 The same material may be used for 3a or the conductive layer 104a, or different materials may be used. When the same material is used for conductive layer 101a, conductive layer 103a, and conductive layer 104a, the light-emitting element The manufacturing costs of the sub-element 272a and the light-emitting element 272b can be reduced. The electrical layer 103a and the conductive layer 104a may each have a configuration in which two or more layers are stacked. stomach.

[0236] Furthermore, the light-emitting layer 130 in the light-emitting element 272a and light-emitting element 272b is in Embodiment 1 It is preferable to have the configuration shown. By doing so, a light-emitting element exhibiting high luminescence efficiency is obtained. It can be manufactured.

[0237] Furthermore, the light-emitting layer 130 and the light-emitting layer 150 are, for example, light-emitting layer 150a and light-emitting layer 150b Thus, a configuration in which two layers are stacked on one or both sides may be used. The two light-emitting layers include the first Two types of light-emitting materials, a first light-emitting material and a second light-emitting material, which have the function of exhibiting different colors. By using each of them, it is possible to obtain light emission containing multiple colors. In particular, the light emission layer 130 and The luminescent material used in each luminescent layer is selected so that the luminescence emitted by the luminescent layer 150 results in a white color. Choosing this option is preferable.

[0238] Furthermore, the light-emitting layer 130 or the light-emitting layer 150 is constructed by laminating three or more layers in one or both of the layers. It may be a composite material, and may also include a layer that does not contain luminescent material.

[0239] As described above, the light-emitting element 272a or the light-emitting element having the configuration of the light-emitting layer shown in Embodiment 1 By using the optical element 272b as a pixel in a display device, a display device with high luminous efficiency can be fabricated. This is possible. That is, a display device having a light-emitting element 272a or a light-emitting element 272b This can reduce power consumption.

[0240] Regarding the other configurations of the light-emitting element 272a and light-emitting element 272b, 270a or light-emitting element 270b, or light-emitting element as shown in Embodiment 1 and Embodiment 2 You should consider the configuration of the element.

[0241] <Method for fabricating a light-emitting element> Next, a method for manufacturing a light-emitting element according to one aspect of the present invention will be described below with reference to Figures 6 and 7. This will be done. Furthermore, the method for fabricating the light-emitting element 272a shown in Figure 5(A) will be explained here. ru.

[0242] Figures 6 and 7 are cross-sectional views illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. .

[0243] The method for fabricating the light-emitting element 272a described below comprises seven steps, from the first to the seventh. ru.

[0244] ≪Step 1≫ The first step is to create electrodes for the light-emitting element (specifically, conductive layers 101 that constitute the electrodes 101). a) conductive layer 103a constituting electrode 103, and conductive layer 104a constituting electrode 104) This is the process of forming it on the substrate 200 (see Figure 6(A)).

[0245] In this embodiment, a conductive layer having the function of reflecting light is formed on the substrate 200. By processing the conductive layer into a desired shape, conductive layer 101a, conductive layer 103a, and conductive Layer 104a is formed. The conductive layer having the function of reflecting light is made of silver and palladium. A copper alloy film (Ag-Pd-Cu film, also called APC) is used. Thus, conductive layer 1 01a, conductive layer 103a, and conductive layer 104a are formed through a process of processing the same conductive layer. This is preferable because it allows for lower manufacturing costs.

[0246] Note that before the first step, multiple transistors may be formed on the substrate 200. Furthermore, the above-mentioned multiple transistors, conductive layer 101a, conductive layer 103a, and conductive layer 104 Points a and a may be electrically connected to each other.

[0247] ≪Step 2≫ The second step is to have a light-transmitting function on the conductive layer 101a that constitutes the electrode 101. A conductive layer 101b is placed on the conductive layer 103a constituting the electrode 103, and has the function of transmitting light. A conductive layer 103b is placed on the conductive layer 104a constituting the electrode 104, and has the function of transmitting light. This is the step of forming the conductive layer 104b (see Figure 6(B)).

[0248] In this embodiment, conductive layers 101a, 103a, and have the function of reflecting light, On 104a, there are conductive layers 101b, 103b, and respectively, which have the function of transmitting light. By forming 104b, electrodes 101, 103, and 104 are formed. ITSO films are used as the conductive layers 101b, 103b, and 104b.

[0249] Furthermore, the conductive layers 101b, 103b, and 104b, which have the function of transmitting light, can be used multiple times. It may be formed in stages. By forming it in stages, suitable microcaches can be formed in each region. The conductive layers 101b, 103b, and 104b can be formed with a film thickness that creates a vitreous structure. Cut.

[0250] ≪Step 3≫ The third step is to form partition walls 145 that cover the ends of each electrode of the light-emitting element. See Figure 6(C).

[0251] The partition wall 145 has an opening that overlaps with the electrode. The conductive film exposed by the opening. This functions as the anode of the light-emitting element. In this embodiment, the partition wall 145 is made of polyimide resin. Use fat.

[0252] Furthermore, in steps 1 to 3, the EL layer (the layer containing organic compounds) is damaged. Because there is no risk, various film formation methods and microfabrication techniques can be applied. This involves forming a reflective conductive layer using a sputtering method, and then using a lithography method to... A pattern is formed on the electrode layer, and then a dry etching method or a wet etching method is used. By processing the conductive layer into an island shape, the conductive layer 101a and electrode 103 that constitute the electrode 101 are formed. A conductive layer 103a constituting the electrode and a conductive layer 104a constituting the electrode 104 are formed. After that, a transparent conductive film is deposited using the sputtering method, and then lithography is used Then, a pattern is formed on the transparent conductive film, and then using a wet etching method The transparent conductive film is processed into island shapes to form electrodes 101, 103, and 104. It forms.

[0253] ≪Step 4≫ The fourth step involves a hole injection layer 111, a hole transport layer 112, a light-emitting layer 150, and an electron transport layer. This is a step to form 113, an electron injection layer 114, and a charge generation layer 115 (see Figure 7(A)). (see).

[0254] As the hole injection layer 111, a material containing a hole transporting material and an acceptor material is co-evaporated. It can be formed by deposition. Co-deposition is the process of depositing multiple different materials together. This is a vapor deposition method in which evaporation occurs simultaneously from an evaporation source. In addition, the hole transport layer 112 is a hole It can be formed by depositing a transportable material.

[0255] The light-emitting layer 150 is selected from among green, yellow-green, yellow, orange, or red. It can be formed by depositing any one of the following guest materials that exhibit light emission. As guest materials, luminescent organic compounds that exhibit fluorescence or phosphorescence can be used. Furthermore, it is preferable to use the light-emitting layer configuration shown in Embodiment 1 and Embodiment 2. Furthermore, the light-emitting layer 150 may have a two-layer configuration. In that case, the two light-emitting layers are It is preferable that the materials each have a different emission color.

[0256] The electron transport layer 113 can be formed by depositing a material with high electron transport properties. It is possible. Furthermore, the electron injection layer 114 is formed by depositing a material with high electron injection properties. It is possible.

[0257] As the charge generation layer 115, electron acceptors are added to a hole transport material. Deposition of a material, or a material to which an electron donor has been added to an electron transport material. It can be formed with.

[0258] ≪Step 5≫ The fifth step involves a hole injection layer 116, a hole transport layer 117, a light-emitting layer 130, and an electron transport layer. This is a step in which 118, the electron injection layer 119, and the electrode 102 are formed (see Figure 7(B)).

[0259] The hole injection layer 116 is made of the same material and is made using the same method as the hole injection layer 111 described above. It can be formed more easily. Also, as the hole transport layer 117, the hole transport layer 11 shown above It can be formed using the same materials and methods as in 2.

[0260] The light-emitting layer 130 is selected from at least one of the following colors: purple, blue, or blue-green. Alternatively, it can be formed by depositing a guest material that exhibits light emission. For this purpose, fluorescent organic compounds can be used. Furthermore, the fluorescent organic compound is single It may be deposited by hand, or it may be deposited after being mixed with other materials. Also, fluorescent organic compounds A guest material is used, and the guest material is excited to a host material with a greater excitation energy than the guest material. It may also be deposited in a dispersed manner.

[0261] The electron transport layer 118 is made of the same material and is constructed using the same method as the electron transport layer 113 described above. It can be formed more easily. Also, as the electron injection layer 119, the electron injection layer 11 shown above It can be formed using the same materials and methods as in 4.

[0262] The electrode 102 consists of a reflective conductive film and a translucent conductive film laminated together. It can be formed as follows. Also, the electrode 102 can be a single-layer structure or a multi-layer structure. That's good too.

[0263] After the above process, regions 222 are formed on electrodes 101, 103, and 104, respectively. A light-emitting element having region B, region 222G, and region 222R is formed on the substrate 200.

[0264] Step 6 The sixth step is to place a light-shielding layer 223, optical element 224B, and optical element 224 on the substrate 220. This is the process of forming G and the optical element 224R (see Figure 7(C)).

[0265] As the light-shielding layer 223, a resin film containing black pigment is formed in the desired area. After that, the base On the plate 220 and the light-shielding layer 223, optical element 224B, optical element 224G, and optical element 2 Forming 24R. As the optical element 224B, a resin film containing blue pigment is applied to the desired region. Formed. In addition, as the optical element 224G, a resin film containing green pigment is formed in a desired region. Furthermore, as the optical element 224R, a resin film containing red pigment is formed in the desired region. do.

[0266] ≪Step 7≫ The seventh step is to have a light-emitting element formed on substrate 200 and a light-emitting element formed on substrate 220 The light-shielding layer 223, optical element 224B, optical element 224G, and optical element 224R are attached. This is the process of sealing the parts together using a sealing material (not shown in the diagram).

[0267] By following the above steps, the light-emitting element 272a shown in Figure 5(A) can be formed.

[0268] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there.

[0269] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described using Figures 8 to 14. do.

[0270] <Example of display device configuration 1> Figure 8(A) is a top view showing the display device 600, and Figure 8(B) is a view of Figure 8(A) along the dashed line AB. , and a cross-sectional view taken along the dashed line CD. The display device 600 is a drive circuit section (signal line It has a drive circuit section 601, a scan line drive circuit section 603, and a pixel section 602. The signal line drive circuit section 601, the scan line drive circuit section 603, and the pixel section 602 are light-emitting elements. It has a function to control light emission.

[0271] Furthermore, the display device 600 includes an element substrate 610, a sealing substrate 604, and a sealing material 605. The area 607 surrounded by the sealing material 605, the routed wiring 608, and the FPC 609 are all included. do.

[0272] Furthermore, the routing wiring 608 is connected to the signal line drive circuit section 601 and the scan line drive circuit section 603. This is wiring for transmitting input signals, and it connects to the FPC609, which is an external input terminal, for video input. It receives signals such as the O signal, clock signal, start signal, and reset signal. Note that here it is FP Only C609 is shown in the diagram, but FPC609 is a printed circuit board (PWB: Pri A wired wiring board may be attached.

[0273] Furthermore, the signal line drive circuit section 601 consists of an N-channel type transistor 623 and a P-channel type A CMOS circuit is formed by combining it with transistor 624. The path section 601 or the scan line drive circuit section 603 includes various CMOS circuits, PMOS circuits, and An NMOS circuit can be used. In addition, in this embodiment, the drive circuit section is mounted on the substrate. The image shows a display device in which the formed driver and pixels are arranged on the same surface, but this is not necessarily required. Alternatively, the drive circuit can be formed externally instead of on the circuit board.

[0274] Furthermore, the pixel section 602 includes a switching transistor 611 and a current control transistor. The lower part electrically connected to the drain of transistor 612 for current control and transistor 612 It has an electrode 613. A partition wall 614 is formed to cover the end of the lower electrode 613. A positive-type photosensitive acrylic resin film can be used as the partition wall 614.

[0275] Furthermore, in order to improve coverage, the upper or lower end of the partition wall 614 has a curved surface with curvature. To ensure that a structure is formed. For example, positive-type photosensitive acrylic is used as the material for the partition wall 614. If so, the upper end of the partition wall 614 will have a curve with a radius of curvature (0.2 μm or more and 3 μm or less). It is preferable to give it a surface. Also, as the partition wall 614, a negative type photosensitive resin or a poly Any type of photosensitive resin can be used.

[0276] Furthermore, the structure of the transistors (transistors 611, 612, 623, 624) is particularly... It is not limited. For example, a staggered transistor may be used. Also, the transistor There are no particular limitations regarding polarity, and it includes N-channel and P-channel transistors. A structure that includes either an N-channel transistor or a P-channel transistor. A structure consisting of only one of the two may also be used. Furthermore, the semiconductor film crystal used in transistors... There are no particular limitations regarding properties. For example, amorphous semiconductor films and crystalline semiconductor films can be used. Yes, it is possible. Also, as semiconductor materials, there are Group 14 (silicon, etc.) semiconductors and compound semiconductors (oxides). Semiconductors (including organic semiconductors), etc., can be used. Examples of transistors include: Energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV By using the above oxide semiconductors, the off-current of the transistor can be reduced. Preferably, the oxide semiconductor is In-Ga oxide, In-M-Zn oxide (M is Aluminum (Al), gallium (Ga), yttrium (Y), zirconium (Zr ), lanthanum (La), cerium (Ce), tin (Sn), hafnium (Hf), or Examples include neodymium (Nd) and others.

[0277] An EL layer 616 and an upper electrode 617 are formed on the lower electrode 613, respectively. The lower electrode 613 functions as the anode, and the upper electrode 617 functions as the cathode. ru.

[0278] Furthermore, the EL layer 616 can be coated using a deposition method with a deposition mask, an inkjet method, or a spin coat. It is formed by various methods such as the law. In addition, other materials that make up the EL layer 616 include It may be a low molecular weight compound or a high molecular weight compound (including oligomers and dendrimers). stomach.

[0279] Furthermore, the lower electrode 613, the EL layer 616, and the upper electrode 617 contribute to the light-emitting element 618. The light-emitting element 618 is formed. The light-emitting element 618 has the configuration of Embodiments 1 to 3. In addition, when multiple light-emitting elements are formed in the pixel section, the first to third embodiments The light-emitting element described in 3 may include both the light-emitting element with other configurations.

[0280] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, A light-emitting element is placed in the region 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The structure is equipped with child 618. Furthermore, the area 607 is filled with filler material. In addition to cases where an inert gas (such as nitrogen or argon) is filled, it is also used in sealant 605. In some cases, it may be filled with UV-curing resin or thermosetting resin, for example, PVC ( Polyvinyl chloride resins, acrylic resins, polyimide resins, epoxy resins, Silicone resin, PVB (polyvinyl butyral) resin, or EVA (ethylene vinyl A resin (such as a luacetate) can be used. A recess is formed in the sealing substrate, and a desiccant is placed therein. Providing this feature can suppress deterioration due to moisture, making it a desirable configuration.

[0281] Furthermore, the optical element 621 is positioned below the sealing substrate 604 so as to overlap with the light-emitting element 618. It is provided therein. Furthermore, a light-shielding layer 622 is provided below the sealing substrate 604. Optical element 621 and the light-shielding layer 622 are the optical element and the light-shielding layer shown in Embodiment 3, respectively. A similar configuration would suffice.

[0282] Furthermore, it is preferable to use epoxy resin or glass frit for the sealant 605. Furthermore, it is desirable that these materials be as impermeable to moisture and oxygen as possible. In addition, as materials used for the sealing substrate 604, glass substrates and quartz substrates are also available, as well as FRP (Fiber Reinforced Plastic). Reinforced Plastics), PVF (Polyvinyl Fluoride), Poly A plastic substrate made of ester or acrylic can be used.

[0283] As described above, the light-emitting element and optical element described in Embodiments 1 to 3 are A display device can be obtained.

[0284] <Example of display device configuration 2> Next, another example of a display device will be explained using Figures 9(A)(B) and 10. Figures 9(A)(B) and 10 are cross-sectional views of a display device according to one embodiment of the present invention.

[0285] Figure 9(A) shows the substrate 1001, the underlay insulating film 1002, the gate insulating film 1003, and the gate insulating film. Poles 1006, 1007, 1008, first interlayer insulating film 1020, second interlayer insulating film 102 1. Peripheral portion 1042, pixel portion 1040, drive circuit portion 1041, lower electrode 102 of light-emitting element 4R, 1024G, 1024B, partition wall 1025, EL layer 1028, upper electrode 1 of light-emitting element The diagram shows 026, the sealing layer 1029, the sealing substrate 1031, the sealing material 1032, and so on.

[0286] Furthermore, Figure 9(A) shows an example of an optical element, including a colored layer (red colored layer 1034R, green A colored layer 1034G and a blue colored layer 1034B are provided on a transparent substrate 1033. A light-shielding layer 1035 may also be provided. A transparent material having a colored layer and a light-shielding layer. The substrate 1033 is aligned and fixed to the substrate 1001. Note that the colored layer and the light-shielding layer are It is covered with an overcoat layer 1036. Also, in Figure 9(A), the colored layer is transparent. Since passing light is red, green, and blue, images can be represented using pixels of these three colors.

[0287] Figure 9(B) shows an example of an optical element, with a colored layer (red colored layer 1034R, green colored layer The color layer 1034G and the blue colored layer 1034B are connected to the gate insulating film 1003 and the first interlayer insulating film. An example of formation between 1020 and substrate 1001 is shown. In this way, the colored layer is formed between substrate 1001 and encapsulating group It may also be provided between the plates 1031.

[0288] Figure 10 shows an example of an optical element, with a colored layer (red colored layer 1034R, green colored layer) 1034G, the blue colored layer 1034B) is connected to the first interlayer insulating film 1020 and the second interlayer insulating film This shows an example of formation between 1021 and substrate 1001. Thus, the colored layer is formed between substrate 1001 and the sealing group It may also be provided between the plates 1031.

[0289] Furthermore, in the display device described above, the side of the substrate 1001 on which the transistor is formed Although a display device with a light extraction structure (bottom emission type) was used, on the encapsulating substrate 1031 side It can also be used as a display device with a structure that extracts light (top emission type).

[0290] <Example of display device configuration 3> An example of a cross-sectional view of a top-emission type display device is shown in Figure 11(A)(B). Figure 11 Figures (A) and (B) are cross-sectional views illustrating a display device according to one embodiment of the present invention, and Figure 9(A) and (B) The drive circuit section 1041, peripheral section 1042, etc. shown in Figure 10 are omitted for illustrative purposes.

[0291] In this case, the substrate 1001 can be a substrate that does not transmit light. Until the connecting electrode that connects to the anode of the optical element is fabricated, it will be a bottom-emission type display device. It is formed in the same manner as above. Then, the third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film may also play a planarization role. The third interlayer insulating film 1037 is In addition to materials similar to those used for the interlayer insulating film in step 2, it can be formed using a variety of other materials.

[0292] The lower electrodes 1024R, 1024G, and 1024B of the light-emitting element are referred to as anodes here, but the negative electrodes are not. It can also be a pole. Also, a top-emission type display like Figure 11(A)(B) is also acceptable. If it is a device, the lower electrodes 1024R, 1024G, and 1024B have the function of reflecting light. It is preferable to do so. Also, an upper electrode 1026 is provided on the EL layer 1028. Electrode 1026 has the function of reflecting light and the function of transmitting light, and lower electrode 1024R, 10 A microcavity structure is employed between 24G, 1024B and the upper electrode 1026. It is preferable to increase the light intensity at a specific wavelength.

[0293] In the top emission structure shown in Figure 11(A), the colored layer (red colored layer 1034) Encapsulation substrate 1031 provided with R, a green colored layer 1034G, and a blue colored layer 1034B) Sealing can be performed using this method. The sealing substrate 1031 is positioned between pixels. A light layer 1035 may be provided. Furthermore, if a light-transmitting substrate is used for the sealing substrate 1031, It is suitable.

[0294] Furthermore, in Figure 11(A), multiple light-emitting elements are shown, and each of these light-emitting elements is colored. While a configuration with layers has been given as an example, the system is not limited to this. For example, as shown in Figure 11(B) Without providing a green colored layer, a red colored layer 1034R and a blue colored layer 1034B are provided. Alternatively, a configuration that displays in full color using three colors—red, green, and blue—is also possible. (See Figure 11(A)) As shown above, when a light-emitting element is provided and a colored layer is provided on each of the light-emitting elements, external light reflection This has the effect of being able to suppress it. On the other hand, as shown in Figure 11(B), the light-emitting element and green If a configuration is used in which a red colored layer and a blue colored layer are provided without a colored layer, then green Because there is little energy loss from the light-emitting element, power consumption can be reduced. It produces the desired effect.

[0295] <Example of display device configuration 4> The display device described above has a configuration having three subpixels (red, green, and blue). However, the secondary colors are four colors (red, green, blue, and yellow, or red, green, blue, and white). A configuration having elements is also possible. Figures 12 to 14 show the lower electrodes 1024R, 1024G, This is a display device configuration having 1024B and 1024Y. Figures 12(A)(B) and Figure 13 is a structure that extracts light (bottom emitter) on the substrate 1001 side where the transistor is formed. This is a display device of the type (seal type), and Figures 14(A) and (B) show that light emission is taken from the sealing substrate 1031 side. It is a display device with a top-emission structure.

[0296] Figure 12(A) shows the optical elements (colored layer 1034R, colored layer 1034G, colored layer 1034B This is an example of a display device in which a colored layer (1034Y) is provided on a transparent substrate (1033). Also, Figure 12 (B) is an optical element (colored layer 1034R, colored layer 1034G, colored layer 1034B) This is an example of a display device formed between the insulating film 1003 and the first interlayer insulating film 1020. Figure 13 shows the optical element (colored layer 1034R, colored layer 1034G, colored layer 1034B, A color layer (1034Y) is formed between the first interlayer insulating film 1020 and the second interlayer insulating film 1021. This is an example of a display device.

[0297] Colored layer 1034R transmits red light, colored layer 1034G transmits green light, colored layer 1034B has the function of transmitting blue light. In addition, the colored layer 1034Y transmits yellow light. A function that allows light to pass through, or a function that transmits multiple colors selected from blue, green, yellow, and red. The colored layer 1034Y transmits multiple lights selected from blue, green, yellow, and red. When it has the function of being yellow, the light transmitted through the colored layer 1034Y may be white. Because light-emitting elements that emit white light have high luminous efficiency, a display having a colored layer 1034Y The device can reduce power consumption.

[0298] Furthermore, in the top-emission type display device shown in Figure 14, the lower electrode 1024Y In the light-emitting element having the same lower electrode 1024R as in the display device in Figure 11(A), Between 1024G, 1024B, 1024Y and the upper electrode 1026, a microcavity A configuration having a structure is preferred. Also, in the display device shown in Figure 14(A), the colored layer (red colored layer Color layer 1034R, green colored layer 1034G, blue colored layer 1034B, and yellow colored layer Sealing can be performed using a sealing substrate 1031 provided with 1034Y).

[0299] The emission exhibited through the microcavity and the yellow colored layer 1034Y is in the yellow region. The emission will have an emission spectrum in the region. Since yellow is a color with high visual sensitivity, yellow emission will occur. A light-emitting element exhibiting this characteristic has high luminous efficiency. That is, a display device having the configuration shown in Figure 14(A) is This can reduce power consumption.

[0300] Furthermore, in Figure 14(A), multiple light-emitting elements are shown, and each of these multiple light-emitting elements is colored. While a configuration with layers has been given as an example, the system is not limited to this. For example, as shown in Figure 14(B) Without providing a yellow colored layer, a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer are provided. A colored layer 1034B is provided, and four colors are used: red, green, blue, and yellow, or red, green, blue, and white. A configuration that enables full-color display may also be used. As shown in Figure 14(A), a light-emitting element and the When a colored layer is provided on each optical element, it has the effect of suppressing external light reflection. It performs. On the other hand, as shown in Figure 14(B), the light-emitting element and the red without a yellow colored layer are used. If the configuration includes a colored layer, a green colored layer, and a blue colored layer, then yellow or white Because there is little energy loss from the light-emitting element, power consumption can be reduced. It produces the desired effect.

[0301] Note that the configuration shown in this embodiment may be appropriately combined with other embodiments or other configurations within this embodiment. They can be combined.

[0302] (Embodiment 5) In this embodiment, a display device having an light-emitting element according to one aspect of the present invention is shown in Figures 15 to We will explain using Figure 17.

[0303] Figure 15(A) is a block diagram illustrating a display device according to one embodiment of the present invention, and Figure 1 5(B) is a circuit diagram illustrating a pixel circuit in a display device according to one aspect of the present invention.

[0304] <Explanation regarding display devices> The display device shown in Figure 15(A) has a region having pixels of the display element (hereinafter referred to as the pixel portion 802 and ( ) and a circuit section ( ) which is located outside the pixel section 802 and has a circuit for driving the pixels. Hereinafter referred to as the drive circuit section 804, and a circuit having a function to protect the element (hereinafter referred to as the protection circuit 804) It has a (6) and a terminal section 807. Note that the protection circuit 806 is not provided. That's fine.

[0305] Part or all of the drive circuit section 804 is formed on the same substrate as the pixel section 802. This is desirable. This allows for a reduction in the number of components and terminals. Drive circuit section 804 If part or all of it is not formed on the same substrate as the pixel section 802, the drive cycle Part or all of road section 804 is COG or TAB (Tape Automated B It can be implemented by (onding).

[0306] The pixel section 802 is arranged in X rows (where X is a natural number greater than or equal to 2) and Y columns (where Y is a natural number greater than or equal to 2). It has a circuit for driving multiple display elements (hereinafter referred to as the pixel circuit 801), and the drive cycle The path section 804 is a circuit that outputs a signal (scan signal) for selecting pixels (hereinafter referred to as the scan line drive circuit). 804a) is used to supply signals (data signals) for driving the pixel display elements. It has a drive circuit such as the signal line drive circuit 804b.

[0307] The scan line driving circuit 804a includes a shift register, etc. The scan line driving circuit 804a is A signal to drive the shift register is input via terminal 807, and the signal is output. For example, the scan line drive circuit 804a receives a start pulse signal, a clock signal, etc. The scan line drive circuit 804a outputs a pulse signal. The scanning signal is supplied to the wiring (and It has the function of controlling the potential of the scan lines (referred to as GL_1 to GL_X). Multiple drive circuits 804a are provided, and the scan line GL_1 is driven by multiple scan line drive circuits 804a. The path to GL_X may be divided and controlled. Alternatively, the scan line drive circuit 804a may use an initialization signal. It has the function of supplying, however, the scan line drive circuit 80 4a can also supply another signal.

[0308] The signal line drive circuit 804b includes a shift register, etc. The signal line drive circuit 804b is Through terminal 807, in addition to signals for driving the shift register, the data signals are generated. A signal (image signal) is input. The signal line drive circuit 804b uses the image signal to drive the pixel circuit It has the function of generating data signals to be written to 801. In addition, the signal line drive circuit 804b The data signal is transmitted according to the pulse signal obtained by inputting the start pulse, clock signal, etc. It has the function of controlling the output of the signal. In addition, the signal line drive circuit 804b is provided with a data signal. It has the function of controlling the potential of the wiring (hereinafter referred to as data lines DL_1 to DL_Y). Alternatively, the signal line drive circuit 804b may have the function of supplying an initialization signal. However, it is not limited to this, and the signal line drive circuit 804b may also supply other signals. It is possible.

[0309] The signal line drive circuit 804b is configured using, for example, multiple analog switches. The signal line drive circuit 804b sequentially turns on multiple analog switches, The image signal can be time-divided and output as a data signal. It can also use shift registers, etc. The signal line drive circuit 804b may be constructed using this.

[0310] Each of the multiple pixel circuits 801 receives a scan signal from one of the multiple scan lines GL. A pulse signal is input via one of several data lines DL to which a data signal is supplied. A data signal is input. In addition, each of the multiple pixel circuits 801 is a scan line drive circuit 804a controls the writing and retention of data in the data signal. For example, m rows and n columns. The pixel circuit 801 of the eye is driven by a scan line drive circuit via the scan line GL_m (where m is a natural number less than or equal to X). A pulse signal is input from 804a, and the data line DL_n( A data signal is input from the signal line drive circuit 804b via n (where n is a natural number less than or equal to Y).

[0311] The protection circuit 806 shown in Figure 15(A) is, for example, a scan line drive circuit 804a and a pixel circuit 8 It is connected to the scan line GL, which is the wiring between 01. Alternatively, the protection circuit 806 drives the signal line. It is connected to the data line DL, which is the wiring between circuit 804b and pixel circuit 801. Alternatively, The protection circuit 806 is connected to the wiring between the scan line drive circuit 804a and the terminal section 807. Yes, it is possible. Alternatively, the protection circuit 806 provides a connection between the signal line drive circuit 804b and the terminal section 807. It can be connected to a wire. The terminal 807 is used to supply power and to the display device from an external circuit. This refers to the part equipped with terminals for inputting control signals and image signals.

[0312] The protection circuit 806, when a potential outside a certain range is applied to the wiring to which it is connected, This is a circuit that creates a conductive state between two wires.

[0313] As shown in Figure 15(A), the pixel section 802 and the drive circuit section 804 each have a protection circuit 80 By providing 6, ESD (Electrostatic Discharge: This can improve the resistance of display devices to overcurrents generated by electrostatic discharge, etc. However, the configuration of the protection circuit 806 is not limited to this, for example, the scan line drive circuit 804a Configuration with protection circuit 806 connected, or with protection circuit 806 connected to signal line drive circuit 804b. This configuration is also possible. Alternatively, a configuration in which the protection circuit 806 is connected to the terminal 807. It can also be done this way.

[0314] Furthermore, in Figure 15(A), the scan line drive circuit 804a and the signal line drive circuit 804b are Therefore, although an example is shown in which the drive circuit section 804 is formed, the configuration is not limited to this. For example, only the scan line drive circuit 804a is formed, and a separately prepared signal line drive circuit is formed. A substrate (for example, a drive circuit substrate formed from a single-crystal semiconductor film or a polycrystalline semiconductor film) is mounted. This configuration is also good.

[0315] <Example of pixel circuit configuration> The multiple pixel circuits 801 shown in Figure 15(A) may be configured as shown in Figure 15(B), for example. It is possible.

[0316] The pixel circuit 801 shown in Figure 15(B) consists of transistors 852 and 854 and a capacitive element 86 It has 2 and a light-emitting element 872.

[0317] One of the source and drain electrodes of transistor 852 is supplied with a data signal. It is electrically connected to the wiring (data line DL_n). Furthermore, the gate of transistor 852 The electrodes are electrically connected to the wiring (scan line GL_m) to which the gate signal is applied.

[0318] Transistor 852 has the function of controlling the writing of data to the data signal.

[0319] One of the pair of electrodes of the capacitive element 862 is connected to a wiring to which a potential is supplied (hereinafter referred to as the potential supply line VL). It is electrically connected to (a), and the other is the source electrode and drain of transistor 852. It is electrically connected to the other electrode.

[0320] The capacitive element 862 functions as a holding capacitor to retain the written data.

[0321] One of the source and drain electrodes of transistor 854 is connected to the potential supply line VL_a. They are electrically connected. Furthermore, the gate electrode of transistor 854 is connected to the gate electrode of transistor 852. It is electrically connected to the other of the source electrode and drain electrode.

[0322] One of the light-emitting element 872's anode and cathode are electrically connected to the potential supply line VL_b. The other end is electrically connected to the source and drain electrodes of transistor 854. It will be done.

[0323] As the light-emitting element 872, the light-emitting elements shown in Embodiments 1 to 3 are used. It is possible.

[0324] Furthermore, a high power supply potential VDD is supplied to one of the potential supply lines VL_a and VL_b. On the other hand, a low power supply potential VSS is applied.

[0325] In a display device having the pixel circuit 801 shown in Figure 15(B), for example, the running shown in Figure 15(A) The line drive circuit 804a sequentially selects the pixel circuit 801 for each row, and the transistor 852 Turn it on and write the data signal.

[0326] When data is written to the pixel circuit 801, the transistor 852 turns off. It enters a holding state. Furthermore, in accordance with the potential of the written data signal, transistor 854 The amount of current flowing between the source electrode and the drain electrode is controlled, and the light-emitting element 872 controls the amount of current flowing through it. It emits light with brightness corresponding to the flow rate. By performing this sequentially for each row, an image can be displayed.

[0327] Furthermore, the pixel circuit has a function to compensate for the effects of fluctuations in the transistor threshold voltage, etc. This may be done. Figures 16(A)(B) and 17(A)(B) show examples of pixel circuits.

[0328] The pixel circuit shown in Figure 16(A) consists of six transistors (transistors 303_1 to 303_3). It has 03_6), a capacitive element 304, and a light-emitting element 305. Also, Figure 16(A) The pixel circuit shown includes wiring 301_1 to 301_5, as well as wiring 302_1 and wiring 30 2_2 is electrically connected. Regarding transistors 303_1 to 303_6... For example, a P-channel transistor can be used.

[0329] The pixel circuit shown in Figure 16(B) is the same as the pixel circuit shown in Figure 16(A), but with transistor 303 This configuration includes the addition of _7. Furthermore, the pixel circuit shown in Figure 16(B) includes wiring 301_6 and Wiring 301_7 is electrically connected. Here, wiring 301_5 and wiring 301_6 These may be electrically connected to each other. Regarding transistor 303_7... For example, a P-channel transistor can be used.

[0330] The pixel circuit shown in Figure 17(A) consists of six transistors (transistors 308_1 to 308_3). It has 08_6), a capacitive element 304, and a light-emitting element 305. Also, Figure 17(A) The pixel circuit shown includes wiring 306_1 to 306_3, and wiring 307_1 to 307_ 3 is electrically connected. Here, wiring 306_1 and wiring 306_3 are electrically connected. They may be electrically connected. Regarding transistors 308_1 to 308_6: For example, a P-channel transistor can be used.

[0331] The pixel circuit shown in Figure 17(B) consists of two transistors (transistor 309_1 and Rangitator 309_2) and two capacitive elements (capacitive element 304_1 and capacitive element 304_ 2) and a light-emitting element 305 are included. Also, the pixel circuit shown in Figure 17(B) has wiring 3 Wirings 11_1 to 311_3, 312_1, and 312_2 are electrically connected. Furthermore, by using the pixel circuit configuration shown in Figure 17(B), for example, voltage input - power A flow-driven system (also called a CVCC system) can be used. Note that transistor 309_ For 1 and 309_2, for example, a P-channel transistor can be used. .

[0332] Furthermore, a light-emitting element according to one aspect of the present invention is an active element having an active element in the pixels of a display device. Trix system, or passive matrix system where the pixels of the display device do not have active elements. It can be applied to each method.

[0333] In the active matrix system, the active elements (active elements, nonlinear elements) are, In addition to transistors, various active elements (active elements, nonlinear elements) can be used. This can be done. For example, MIM (Metal Insulator Metal), or T It is also possible to use elements such as FD (Thin Film Diode). Because it involves fewer manufacturing steps, it is possible to reduce manufacturing costs or improve yield. Alternatively, these elements can improve the aperture ratio due to their small size. This allows for lower power consumption and higher brightness.

[0334] Other than the active matrix method, there are active elements (active elements, nonlinear elements) It is also possible to use a passive matrix type that does not use active elements. Because it does not use sub-elements or nonlinear elements, the manufacturing process is simpler, resulting in reduced manufacturing costs or higher yield. This can improve the performance. Alternatively, active elements (active elements, nonlinear elements) can be used. Because it does not exist, the aperture ratio can be improved, leading to lower power consumption or higher brightness. It is possible.

[0335] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible.

[0336] (Embodiment 6) In this embodiment, a display device having a light-emitting element according to one aspect of the present invention, and the display device An electronic device with an input device attached will be explained using Figures 18 to 22.

[0337] <Explanation regarding the touch panel 1> In this embodiment, as an example of electronic equipment, a display device and an input device are combined. This document describes the Touch Panel 2000. It also explains the Touch Sensor as an example of an input device. This section explains the case where the character "Sa" is present.

[0338] Figures 18(A) and 18(B) are perspective views of the Touch Panel 2000. In section B), for clarity, typical components of the touch panel 2000 are shown.

[0339] The touch panel 2000 has a display device 2501 and a touch sensor 2595 (Figure 1). See 8(B). Also, the touch panel 2000 is made up of substrate 2510, substrate 2570, and substrate It has a plate 2590. Note that substrates 2510, 2570, and 2590 are all It is flexible. However, any one of substrates 2510, 2570, and 2590 The configuration may be one or all of which lack flexibility.

[0340] The display device 2501 has multiple pixels on the substrate 2510 and supplies signals to these pixels. It has multiple wirings 2511. The multiple wirings 2511 are located on the outer periphery of the substrate 2510. It is routed through, and a portion of it forms terminal 2519. Terminal 2519 is FPC2509 (1) is electrically connected to the signal line drive circuit 2503s. The signal from (1) can be supplied to multiple pixels.

[0341] The circuit board 2590 has a touch sensor 2595 and is electrically connected to the touch sensor 2595. It has multiple wires 2598. The multiple wires 2598 are routed around the outer periphery of the substrate 2590. A portion of it forms a terminal. This terminal is electrically connected to FPC2509(2). The process continues. Note that in Figure 18(B), for clarity, the back side of substrate 2590 (substrate 2510) is shown. The electrodes and wiring of the touch sensor 2595, which is located on the opposite side, are shown with solid lines. .

[0342] For example, a capacitive touch sensor can be used as the touch sensor 2595. Capacitive capacitance methods include surface capacitance and projected capacitance.

[0343] Projected capacitance systems are classified into self-capacitance and mutual-capacitance types, mainly based on differences in their driving methods. There are several advantages. Using a mutual capacitance method is preferable because it enables simultaneous multi-point detection.

[0344] Note that the touch sensor 2595 shown in Figure 18(B) is a projected capacitive touch sensor. This configuration applies the "S" setting.

[0345] Furthermore, the touch sensor 2595 can detect the proximity or contact of an object to be detected, such as a finger. Yes, various sensors can be applied.

[0346] The projected capacitive touch sensor 2595 has electrodes 2591 and 2592. Electrode 2591 is electrically connected to one of the multiple wires 2598, and electrode 2592 is Connect electrically to any of the other wires 2598.

[0347] As shown in Figures 18(A) and 18(B), the electrode 2592 is arranged in multiple repeating directions. It has a shape in which the quadrilaterals are connected at their corners.

[0348] Electrode 2591 is quadrilateral and repeats in a direction intersecting the direction in which electrode 2592 extends. It is positioned.

[0349] Wiring 2594 is electrically connected to the two electrodes 2591 that sandwich electrode 2592. A shape that minimizes the area of ​​the intersection between electrode 2592 and wiring 2594 is preferable. This reduces the area where electrodes are not provided, thereby reducing variations in transmittance. Yes, it is possible. As a result, it reduces the variation in brightness of the light transmitted through the touch sensor 2595. It is possible.

[0350] Note that the shapes of electrodes 2591 and 2592 are not limited to these and can take on various shapes. For example, multiple electrodes 2591 are arranged so that there are as few gaps as possible, and an insulating layer is used. Multiple electrodes 2592 are provided spaced apart so that there is a region that does not overlap with electrode 2591. This configuration may also be used. In this case, between the two adjacent electrodes 2592, there is an electrical connection between them. Providing an insulated dummy electrode is preferable because it reduces the area of ​​regions with different transmittances. .

[0351] <Explanation regarding display devices> Next, the details of the display device 2501 will be explained using Figure 19(A). This corresponds to the cross-sectional view between the dashed line X1 and X2 shown in Figure 18(B).

[0352] The display device 2501 has a plurality of pixels arranged in a matrix. These pixels are display elements. It has a child and a pixel circuit that drives the display element.

[0353] The following explanation applies when a light-emitting element that emits white light is applied to a display element. As explained above, the display elements are not limited to these. For example, the light emitted from each adjacent pixel You may use light-emitting elements with different emission colors to achieve a different color.

[0354] For example, substrates 2510 and 2570 have a water vapor transmission rate of 1 × 10⁻⁶ -5 g. m -2 ·day -1 The following is preferably 1 × 10 -6 g·m -2 ·day -1 The following is possible Flexible materials can be suitably used. Alternatively, the thermal expansion coefficient of the substrate 2510 and the base It is preferable to use a material whose thermal expansion coefficient is approximately equal to that of plate 2570. For example, linear expansion coefficient is 1 x 10 -3 / K or less, preferably 5 × 10 -5 / K or less, more comfortable 1×10 - 5 Materials with a temperature of / K or lower can be suitably used.

[0355] The substrate 2510 includes an insulating layer 2510a that prevents the diffusion of impurities to the light-emitting element, and a flexible Adhesive layer 2 for bonding substrate 2510b, insulating layer 2510a, and flexible substrate 2510b It is a laminate having 510c. Furthermore, the substrate 2570 is a substrate that prevents the diffusion of impurities to the light-emitting element. An insulating layer 2570a to prevent leakage, a flexible substrate 2570b, and the insulating layer 2570a and the flexible substrate The laminate has an adhesive layer 2570c that bonds 2570b together.

[0356] Examples of adhesive layers 2510c and 2570c include polyester, polyolefin, etc. Polyamide (nylon, aramid, etc.), polyimide, polycarbonate, or acrylic Ryl, urethane, and epoxy can be used. In addition, resins having siloxane bonds can be used. The following materials can be used.

[0357] Furthermore, a sealing layer 2560 is provided between substrate 2510 and substrate 2570. (Sealing layer 2560) It is preferable that it has a refractive index greater than that of air. Also, as shown in Figure 19(A), sealing If light is to be extracted to the layer 2560 side, the sealing layer 2560 can also serve as an optical bonding layer. Cut.

[0358] Furthermore, a sealing material may be formed on the outer periphery of the sealing layer 2560. As a result, the region surrounded by substrate 2510, substrate 2570, sealing layer 2560, and sealing material The configuration can include a light-emitting element 2550R. The sealing layer 2560 is as follows: An inert gas (such as nitrogen or argon) may be used for filling. Furthermore, a desiccant may be placed inside the inert gas. A configuration may be provided to adsorb moisture, etc. Also, as the above-mentioned sealing material, for example In that case, epoxy resin or glass frit is preferable. Also, the material used for the sealant As for the material, it is preferable to use a material that does not permeate moisture or oxygen.

[0359] Furthermore, the display device 2501 has pixels 2502R. Also, pixels 2502R are light-emitting pixels. It has a joule of 2580R.

[0360] Pixel 2502R is connected to the light-emitting element 2550R and supplies power to the light-emitting element 2550R. It has a transistor 2502t that can do this. Note that transistor 2502t is a pixel It functions as part of the circuit. Also, the light-emitting module 2580R and the light-emitting element 2550R, It has a colored layer 2567R.

[0361] The light-emitting element 2550R has a lower electrode, an upper electrode, and an EL layer between the lower electrode and the upper electrode. It has the following characteristics. As the light-emitting element 2550R, for example, the light-emitting elements shown in Embodiments 1 to 3 Optical elements can be applied.

[0362] Furthermore, a microcavity structure is employed between the lower and upper electrodes, allowing for specific wavelengths. The light intensity may be increased.

[0363] Furthermore, if the sealing layer 2560 is provided on the side from which light is extracted, the sealing layer 2560 is It is in contact with the optical element 2550R and the colored layer 2567R.

[0364] The colored layer 2567R is located in a position that overlaps with the light-emitting element 2550R. A portion of the light emitted by 2550R passes through the colored layer 2567R, and is emitted in the direction of the arrow shown in the figure. It is emitted to the outside of the 2580R optical module.

[0365] Furthermore, the display device 2501 is provided with a light-shielding layer 2567BM in the direction from which light is emitted. The light-shielding layer 2567BM is provided so as to surround the colored layer 2567R.

[0366] The colored layer 2567R only needs to have the function of transmitting light in a specific wavelength range. For example, a color filter that transmits light in the red wavelength range, and a color filter that transmits light in the green wavelength range. Color filters, color filters that transmit light in the blue wavelength range, color filters that transmit light in the yellow wavelength range Transparent color filters can be used. Each color filter is made from various materials. Using printing methods, inkjet methods, and etching methods using photolithography technology, It can be formed in any way.

[0367] Furthermore, the display device 2501 is provided with an insulating layer 2521. The insulating layer 2521 is made of transistors. It covers the ZISTA 2502t. The insulating layer 2521 flattens the irregularities caused by the pixel circuit. It has the function to do so. In addition, the insulating layer 2521 is given the function to suppress the diffusion of impurities. This may be done. This will prevent a decrease in the reliability of transistors such as the 2502t due to the diffusion of impurities. It can be suppressed.

[0368] Furthermore, the light-emitting element 2550R is formed above the insulating layer 2521. The lower electrode of the 550R is provided with a partition wall 2528 that overlaps the end of the lower electrode. Furthermore, a spacer that controls the distance between substrate 2510 and substrate 2570 is placed on the partition wall 2528. It may be formed.

[0369] The scan line driving circuit 2503g(1) consists of a transistor 2503t and a capacitive element 2503c It has the following characteristics. Furthermore, the drive circuit can be formed on the same substrate using the same process as the pixel circuit. ru.

[0370] Furthermore, wiring 2511 that can supply signals is provided on the circuit board 2510. Furthermore, terminal 2519 is provided on wiring 2511. Also, terminal 2519 has FP C2509(1) is electrically connected. Also, FPC2509(1) receives the video signal. It has the function of supplying clock signals, start signals, reset signals, etc. Note: FPC2 A printed circuit board (PWB) may be attached to 509(1).

[0371] Furthermore, transistors of various structures can be applied to the display device 2501. (Figure) In 19(A), an example is given of the case where a bottom-gate type transistor is applied. However, it is not limited to this, and for example, as shown in Figure 19(B), a top-gate type transient The system may also be configured to apply the st to the display device 2501.

[0372] Furthermore, regarding the polarity of transistors 2502t and 2503t, there are no particular limitations. There is no fixed definition, and the structure has N-channel and P-channel transistors, N-channel type A structure consisting of either a transistor or a P-channel transistor is used. It may be there. Also, the semiconductor film crystal used in transistors 2502t and 2503t There are no particular limitations regarding properties. For example, amorphous semiconductor films and crystalline semiconductor films can be used. Yes, it is possible. Also, as a semiconductor material, Group 14 semiconductors (for example, semiconductors containing silicon) are used. Compound semiconductors (including oxide semiconductors), organic semiconductors, etc. can be used. Either or both of transistors 2502t and 2503t have energy gear Oxides with a cap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more. Using semiconductors is preferable because it reduces the transistor's off-current. Examples of such oxide semiconductors include In-Ga oxide and In-M-Zn oxide (where M is Al, G). Examples include (representing a, Y, Zr, La, Ce, Sn, Hf, or Nd).

[0373] <Explanation regarding touch sensors> Next, we will explain the details of the touch sensor 2595 using Figure 19(C). Figure 19 (C) corresponds to the cross-sectional view between the dashed line X3 and X4 shown in Figure 18(B).

[0374] The touch sensor 2595 has electrodes 2591 and electrodes arranged in a staggered pattern on the substrate 2590. 2592, an insulating layer 2593 covering electrodes 2591 and 2592, and adjacent electrodes 25 It has wiring 2594 that electrically connects 91.

[0375] Electrodes 2591 and 2592 are formed using a light-transmitting conductive material. Conductive materials having this property include indium oxide, indium tin oxide, and indium zinc oxide. Conductive oxides such as zinc oxide, zinc oxide, and zinc oxide with added gallium can be used. Furthermore, a film containing graphene can also be used. A film containing graphene is, for example, a film-like structure. A film containing graphene oxide formed on the surface can be reduced to form a new film. Methods such as applying heat can be cited.

[0376] For example, a light-transmitting conductive material is deposited on a substrate 2590 by sputtering. Afterward, unwanted parts are removed using various pattern formation techniques such as photolithography. Electrodes 2591 and 2592 can be formed.

[0377] Furthermore, the materials used for the insulating layer 2593 include, for example, resins such as acrylic and epoxy. In addition to resins containing siloxane bonds, silicon oxide, silicon oxide nitride, aluminum oxide Inorganic insulating materials such as MU can also be used.

[0378] Furthermore, an opening reaching the electrode 2591 is provided in the insulating layer 2593, and the wiring 2594 is adjacent to it. It is electrically connected to electrode 2591. The light-transmitting conductive material increases the aperture ratio of the touch panel. Because it can be done this way, it can be suitably used in wiring 2594. Also, electrode 2591 Furthermore, materials with higher conductivity than electrode 2592 are preferable for wiring 2594 because they can reduce electrical resistance. It can be used appropriately.

[0379] The electrode 2592 extends in one direction, and multiple electrodes 2592 are arranged in a stripe pattern. Furthermore, the wiring 2594 is provided intersecting with the electrode 2592.

[0380] A pair of electrodes 2591 are provided flanking one electrode 2592. Also, the wiring 2594 is A pair of electrodes 2591 are electrically connected.

[0381] Note that the multiple electrodes 2591 are not necessarily arranged in a direction perpendicular to that of a single electrode 2592. It is not necessary to do so; they may be arranged to form an angle greater than 0 degrees but less than 90 degrees.

[0382] Furthermore, wiring 2598 is electrically connected to electrode 2591 or electrode 2592. A portion of the wiring 2598 functions as a terminal. Wiring 2598 can be, for example, made of aluminum. Nium, gold, platinum, silver, nickel, titanium, tungsten, chromium, molybdenum, iron, corn Using metallic materials such as balsamic, copper, or palladium, or alloy materials containing such metallic materials. It is possible.

[0383] Furthermore, an insulating layer is provided to cover the insulating layer 2593 and the wiring 2594, and the touch sensor 2595 It may be protected.

[0384] Furthermore, the connecting layer 2599 electrically connects the wiring 2598 and the FPC2509(2). .

[0385] The connecting layer 2599 is an anisotropic conductive film (ACF: Anisotropic C (conductive film) or anisotropic conductive paste (ACP: Anisotropic) You can use tools such as IC Conductive Paste.

[0386] <Explanation regarding the touch panel 2> Next, we will explain the details of the touch panel 2000 using Figure 20(A). Figure 20 (A) corresponds to the cross-sectional view between the dashed line X5 and X6 shown in Figure 18(A).

[0387] The touch panel 2000 shown in Figure 20(A) is the same as the display device 250 described in Figure 19(A). This configuration consists of 1 and the touch sensor 2595 described in Figure 19(C) bonded together.

[0388] Furthermore, the touch panel 2000 shown in Figure 20(A) is shown in Figures 19(A) and 19(C). In addition to the configuration described, it also includes an adhesive layer 2597 and an anti-reflective layer 2567p.

[0389] The adhesive layer 2597 is provided in contact with the wiring 2594. The substrate 2590 is attached to the substrate 2570 so that the sensor 2595 overlaps the display device 2501. They are joined together. Furthermore, it is preferable that the adhesive layer 2597 has light-transmitting properties. Also, adhesive layer 2 For 597, a thermosetting resin or an ultraviolet curing resin can be used. For example, Using acrylic resin, urethane resin, epoxy resin, or siloxane resin It is possible.

[0390] The anti-reflective layer 2567p is provided in a position that overlaps with the pixel. For example, a circular polarizer can be used.

[0391] Next, for a touch panel with a configuration different from that shown in Figure 20(A), see Figure 20(B). I will use it to explain.

[0392] Figure 20(B) is a cross-sectional view of the touch panel 2001. The touch panel shown in Figure 20(B) Nell 2001 is a touch panel 2000 and a display device 2501 as shown in Figure 20(A). The position of the touch sensor 2595 is different. Here, we will explain the different configurations in detail. Where applicable, refer to the description of Touch Panel 2000 for details on how to use the provided configuration.

[0393] The colored layer 2567R is located in a position that overlaps with the light-emitting element 2550R. Also, in Figure 20(B) The light-emitting element 2550R shown emits light on the side where the transistor 2502t is located. As a result, some of the light emitted by the light-emitting element 2550R passes through the colored layer 2567R, The light is emitted to the outside of the light-emitting module 2580R in the direction of the arrow shown in the diagram.

[0394] Furthermore, the touch sensor 2595 is located on the circuit board 2510 side of the display device 2501. .

[0395] The adhesive layer 2597 is located between substrate 2510 and substrate 2590 and touches the display device 2501. Attach the Chisensa 2595.

[0396] As shown in Figures 20(A) and 20(B), the light emitted from the light-emitting element is directed towards the upper side of the substrate 2510. It is sufficient if it is ejected from either the lower side or both.

[0397] <Explanation of how the touch panel is operated> Next, an example of how to drive a touch panel will be explained using Figures 21(A) and 21(B). cormorant.

[0398] Figure 21(A) is a block diagram showing the configuration of a mutually capacitive touch sensor. (A) shows the pulse voltage output circuit 2601 and the current detection circuit 2602. In Figure 21(A), the electrodes 2621 to which the pulse voltage is applied are designated as X1-X6, and the current changes... The electrodes 2622 that detect the change are shown as Y1-Y6, each represented by six wires. Furthermore, Figure 21(A) shows the capacitance formed by the superposition of electrode 2621 and electrode 2622. This indicates 2603. Note that electrodes 2621 and 2622 have interchangeable functions. You may do so.

[0399] The pulse voltage output circuit 2601 is a circuit for sequentially applying pulses to the X1-X6 wiring. Therefore, when a pulse voltage is applied to the wiring X1-X6, the capacitance 2603 is formed. An electric field is generated between pole 2621 and electrode 2622. This electric field generated between electrodes is affected by shielding, etc. By causing a change in the mutual capacitance of the 2603 capacitance, the proximity of the detected object, or It can detect contact.

[0400] The current detection circuit 2602 detects changes in the mutual capacitance of capacitor 2603, and the wiring of Y1-Y6 This is a circuit for detecting changes in current. In the wiring of Y1-Y6, proximity of the object to be detected, Alternatively, if there is no contact, the detected current value will not change, but if the object being detected is nearby, When the mutual capacitance decreases due to contact, a change in the current value is detected. Output can be performed using an integrating circuit or similar.

[0401] Next, Figure 21(B) shows the input of the mutual capacitive touch sensor shown in Figure 21(A). The timing chart of the output waveform is shown. Figure 21(B) shows the timing of each matrix in one frame period. The system detects the object to be detected. Also, in Figure 21(B), the system does not detect the object to be detected (non-touch). This shows two cases: when detecting an object (touch) and when detecting an object to be detected. Note that Figure 2 In 1(B), the waveform of the voltage value corresponding to the current value detected in the Y1-Y6 wiring is shown. ru.

[0402] A pulse voltage is applied sequentially to the wiring of X1-X6, and Y1- The waveform changes in the Y6 wiring. If there is no proximity or contact with the detected object, X1-X6 The waveforms of Y1-Y6 change uniformly in response to changes in the voltage of the wiring. Meanwhile, when the object to be detected is nearby... Alternatively, at the point of contact, the current value decreases, and therefore the waveform of the corresponding voltage value also changes. ru.

[0403] In this way, by detecting changes in mutual capacitance, the proximity or contact of the object being detected can be detected. It is possible.

[0404] <Explanation regarding the sensor circuit> Furthermore, in Figure 21(A), only a capacitor 2603 is provided at the wiring intersection as a touch sensor. The configuration of a passive matrix type touch sensor is shown, but it has transistors and capacitors. It may also be an active-matrix type touch sensor. An example of a sensor circuit included in the sensor is shown in Figure 22.

[0405] The sensor circuit shown in Figure 22 consists of a capacitor 2603, a transistor 2611, and a transistor It has transistor 2612 and transistor 2613.

[0406] Transistor 2613 receives a signal G2 at its gate, and either its source or drain... A voltage VRES is applied, and the other side is one electrode of capacitor 2603 and transistor 2611 It is electrically connected to the gate. Transistor 2611 has either the source or the drain Electrically connect either the source or drain of transistor 2612, and apply a voltage VS to the other side. S is given. Transistor 2612 is given a signal G1 at its gate, and source or The other end of the drain is electrically connected to the wiring ML. The other electrode of the 2603 capacitance has a voltage VS. S is given.

[0407] Next, we will explain the operation of the sensor circuit shown in Figure 22. First, as the signal G2, When a potential is applied that turns on transistor 2613, the gate of transistor 2611 A potential corresponding to the voltage VRES is applied to node n to which the signal G2 is connected. Next, the signal G2 and By applying a potential that turns off transistor 2613, the potential at node n becomes It is retained.

[0408] Next, the mutual capacitance of capacitance 2603 changes due to the proximity or contact of a detected object such as a finger. Consequently, the potential of node n changes from VRES.

[0409] The read operation applies a potential to signal G1 that turns on transistor 2612. The current flowing through transistor 2611, i.e., the current flowing through wiring ML, is determined by the potential of the current n. The current changes. By detecting this current, the proximity or contact of the object to be detected can be detected. It is possible.

[0410] As for transistors 2611, 2612, and 2613, It is preferable to use an oxide semiconductor layer as the semiconductor layer in which the channel region is formed. In particular, By applying such a transistor to the transistor 2613, the potential at node n can be changed. This makes it possible to retain the data for a long period of time, and the operation of resupplying VRES to node n ( This can reduce the frequency of fresh operations.

[0411] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible.

[0412] (Embodiment 7) In this embodiment, a display module and electronic device having a light-emitting element according to one aspect of the present invention This will be explained using Figures 23 and 24.

[0413] <Explanation regarding the display module> The display module 8000 shown in Figure 23 consists of an upper cover 8001 and a lower cover 8002. In between, touch sensor 8004 connected to FPC8003, and FPC8005 connected It has a display device 8006, a frame 8009, a printed circuit board 8010, and a battery 8011. do.

[0414] A light-emitting element according to one aspect of the present invention can be used, for example, in a display device 8006.

[0415] The upper cover 8001 and the lower cover 8002 are connected to the touch sensor 8004 and the display device 8 The shape and dimensions can be appropriately modified to match the size of 006.

[0416] The touch sensor 8004 is a resistive or capacitive touch sensor connected to the display device 8 It can be used superimposed on 006. Also, the opposing substrate (encapsulation substrate) of the display device 8006 It is also possible to give it a touch sensor function. Furthermore, the display device 8006 It is also possible to install a light sensor within each pixel to create an optical touch sensor.

[0417] Frame 8009 provides protection for the display device 8006, as well as the operation of the printed circuit board 8010. It has the function of an electromagnetic shield to block electromagnetic waves generated by [unclear]. The Mu8009 may also function as a heat sink.

[0418] The printed circuit board 8010 contains power supply circuits and signals for outputting video and clock signals. It has a power processing circuit. The power supply that provides power to the power supply circuit is an external commercial power supply. Alternatively, a separate power source, the battery 8011, may also be used. This can be omitted when using commercial power.

[0419] Furthermore, the display module 8000 includes components such as polarizing plates, phase difference plates, and prism sheets. They may also be provided.

[0420] <Explanation regarding electronic equipment> Figures 24(A) to 24(G) show electronic devices. These electronic devices are enclosed in a housing. Body 9000, display unit 9001, speaker 9003, operation keys 9005 (power switch, or (including the operating switch), connection terminal 9006, sensor 9007 (force, displacement, position, velocity, Acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electricity To measure fields, currents, voltages, power, radiation, flow rates, humidity, gradients, vibrations, odors, or infrared radiation. It may have a microphone 9008 (including functions), etc.

[0421] The electronic devices shown in Figures 24(A) to 24(G) can have a variety of functions. For example, a function that displays various information (still images, videos, text images, etc.) on the display unit, Chiss sensor function, calendar, date or time display function, various software ( The program controls processing, provides wireless communication, and uses wireless communication to perform various tasks. Features include the ability to connect to computer networks and transmit various types of data using wireless communication. Alternatively, it can perform receiving functions, or read programs or data recorded on a recording medium and display them. It can have a function to display on the display unit, etc. Note that Figures 24(A) to 24(G) The functions that the electronic devices shown may have are not limited to these, and may have a variety of functions. This is possible. Also, although not shown in Figures 24(A) to 24(G), electronic devices include: The configuration may have multiple display units. Furthermore, the electronic device may be equipped with a camera or the like to capture still images. Functions for taking photos, recording videos, and recording images on a storage medium (external or built into the camera). It may also have a function to save the image to the display unit, a function to display the captured image on the display unit, etc.

[0422] Details of the electronic equipment shown in Figures 24(A) to 24(G) will be explained below.

[0423] Figure 24(A) is a perspective view showing the personal digital assistant 9100. The display unit 9001 has flexibility. Therefore, it can be used on the curved surface of the curved housing 9000. The display unit 9001 can be incorporated accordingly. Furthermore, the display unit 9001 is a touch sensor. It features a stylus that allows you to operate it by touching the screen with your finger or a stylus. For example, the display By touching the icon displayed on the display unit 9001, you can launch the application. can.

[0424] Figure 24(B) is a perspective view showing the personal digital assistant 9101. The personal digital assistant 9101 is It has one or more functions selected from, for example, a telephone, a notebook, or an information viewing device. Physically, it can be used as a smartphone. Furthermore, the mobile information terminal 9101 is... The speaker 9003, connection terminal 9006, sensor 9007, etc. are omitted from the diagram, but It can be installed in the same position as the portable information terminal 9100 shown in 24(A). The information terminal 9101 can display text and image information on its multiple surfaces. For example, Three operation buttons 9050 (also called operation icons or simply icons) are on the display unit 900. It can be displayed on one side of 1. Also, the information 9051 shown by the dashed rectangle is displayed on the display unit 90 It can be displayed on other sides of 01. For example, information 9051 is an email. A display that notifies you of incoming calls from social networking services (SNS) or phone calls. Subject of email or social media post, sender's name, date and time, time, This includes battery level, antenna signal strength, etc. Alternatively, information 9051 may be displayed. Instead of displaying information 9051, you may also display an operation button 9050 or the like at that location.

[0425] Figure 24(C) is a perspective view showing the personal digital assistant 9102. The personal digital assistant 9102 is The display unit 9001 has the function of displaying information on three or more sides. Here, information 9052, This shows an example where information 9053 and information 9054 are displayed on different sides. For example, The user of the mobile information terminal 9102 stores the mobile information terminal 9102 in the breast pocket of their clothing. In this state, you can check the display (information 9053 in this case). Specifically, when an incoming call is received... The phone number or name of the caller can be observed from above the mobile information terminal 9102. The information is displayed on the device. The user can view the information without taking the portable information terminal 9102 out of their pocket. This allows you to check and decide whether or not to answer the call.

[0426] Figure 24(D) is a perspective view showing the wristwatch-type personal information terminal 9200. Personal information terminal The 9200 is a mobile phone, email, document viewing and creation, music playback, and internet communication. It can run various applications such as computer games. The display unit 9001 has a curved display surface, and displays are performed along the curved display surface. It can do this. Furthermore, the personal information terminal 9200 can perform standardized short-range wireless communication. This is possible. For example, by communicating with a wireless headset, It is also possible to make calls using the free-call function. In addition, the mobile information terminal 9200 has a connection terminal 9006. It has the capability to directly exchange data with other information terminals via a connector. Charging can also be performed via connection terminal 9006. Note that the charging operation is performed via connection terminal 900 This may also be done by wireless power transfer without using 6.

[0427] Figures 24(E),(F), and(G) are perspective views showing a foldable portable information terminal 9201. Furthermore, Figure 24(E) is a perspective view of the mobile information terminal 9201 in an unfolded state, and Figure 24 (F) changes the mobile information terminal 9201 from one state to the other, either unfolded or folded. This is a perspective view of the device in the process of being folded, with Figure 24(G) showing the portable information terminal 9201 in its folded state. This is a perspective view of the device. The 9201 portable information terminal offers excellent portability when folded, and when unfolded... In this configuration, the seamless, wide display area provides excellent readability. (Portable Information Terminal 92) The display unit 9001 of 01 is connected by three housings 9000 via a hinge 9055. It is supported by bending the two housings 9000 via the hinge 9055. Furthermore, the mobile information terminal 9201 can be reversibly transformed from an unfolded state to a folded state. This is possible. For example, the mobile information terminal 9201 can bend with a radius of curvature of 1 mm or more and 150 mm or less. It is possible to do so.

[0428] The electronic device described in this embodiment has a display unit for displaying some kind of information. The present invention is characterized by the fact that, however, the light-emitting element in one aspect of the present invention is an electronic device that does not have a display unit. It can also be applied to the display unit of the electronic device described in this embodiment. In other words, a configuration that is flexible and can display along a curved display surface, or a folding While examples of foldable display unit configurations have been given, the system is not limited to these, and may also include non-flexible, planar displays. The display may also be configured to appear in the section.

[0429] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible.

[0430] (Embodiment 8) In this embodiment, a light-emitting device having a light-emitting element according to one aspect of the present invention is shown in Figure 25 and This will be explained using Figure 26.

[0431] A perspective view of the light-emitting device 3000 shown in this embodiment is shown in Figure 25(A). Figure 25(B) shows the cross-sectional views corresponding to the section between the dashed lines E and F. In A), some of the components are shown with dashed lines to avoid complexity in the drawing.

[0432] The light-emitting device 3000 shown in Figures 25(A) and (B) consists of a substrate 3001 and a light-emitting device on the substrate 3001. The optical element 3005, the first sealing region 3007 provided on the outer periphery of the light-emitting element 3005, and It has a second sealing region 3009 provided on the outer periphery of the first sealing region 3007.

[0433] Furthermore, the light emitted from the light-emitting element 3005 is emitted from either substrate 3001 or substrate 3003. Or they are emitted from both. In Figures 25(A)(B), the emission from the light-emitting element 3005 This section describes a configuration in which light is emitted downwards (towards the substrate 3001).

[0434] Furthermore, as shown in Figures 25(A) and (B), the light-emitting device 3000 has a light-emitting element 3005. A double sealing structure is arranged surrounded by a first sealing region 3007 and a second sealing region 3009. It is constructed in a double-sealed structure that prevents external impurities from entering the light-emitting element 3005 side (e.g., For example, water, oxygen, etc. can be suitably suppressed. However, the first sealing region 300 7 and the second sealing region 3009 do not necessarily need to be provided. For example, the first sealing region 3 It may also consist solely of 007.

[0435] In Figure 25(B), the first sealing region 3007 and the second sealing region 3009 are , provided in contact with substrates 3001 and 3003. However, it is not limited to this, for example If, then, one or both of the first sealing region 3007 and the second sealing region 3009 are located on the substrate 30 The configuration may also involve providing the insulating film or conductive film formed above 01 in contact with it. Alternatively, one or both of the first sealing region 3007 and the second sealing region 3009 are substrate The 3003 may be configured to be in contact with an insulating film or conductive film formed below it. stomach.

[0436] Substrates 3001 and 3003 are the same as the substrate 20 described in Embodiment 3 above. 0 and the same configuration as substrate 220 should be used. The light-emitting element 3005 should be the same as in the previous implementation. The same configuration as the light-emitting element described in the description should be used.

[0437] The first sealing region 3007 is a material containing glass (e.g., glass frit, glass). A ribbon or similar material can be used. Furthermore, the second sealing region 3009 may be a resin-containing material. This can be used. By using a material containing glass as the first sealing region 3007, Productivity and sealing properties can be improved. In addition, the second sealing region 3009 contains resin. By using this material, impact resistance and heat resistance can be improved. However, the first sealing area 3007 and the second sealing region 3009 are, but are not limited to, the first sealing region 3007 The first part is formed from a resin-containing material, and the second sealing region 3009 is formed from a glass-containing material. That's good too.

[0438] Furthermore, the above-mentioned glass frits include, for example, magnesium oxide, calcium oxide, Strontium oxide, barium oxide, cesium oxide, sodium oxide, potassium oxide, acid Boron oxide, vanadium oxide, zinc oxide, tellurium oxide, aluminum oxide, silicon dioxide, acid Lead oxide, tin oxide, phosphorus oxide, ruthenium oxide, rhodium oxide, iron oxide, copper oxide, magnesium dioxide Niobium oxide, molybdenum oxide, titanium oxide, tungsten oxide, bismuth oxide, Zirconium oxide, lithium oxide, antimony oxide, lead borate glass, tin phosphate glass , including vanadate glass or borosilicate glass, etc. In order to absorb infrared light, Preferably, both contain one or more transition metals.

[0439] Furthermore, as for the glass frit mentioned above, for example, by applying frit paste onto a substrate, This is then subjected to heat treatment or laser irradiation. The frit paste contains the above glass frit It contains a stencil and a resin (also called a binder) diluted with an organic solvent. A net containing an absorbent that absorbs light of the wavelength of laser light may also be used. For example, it is preferable to use an Nd:YAG laser or a semiconductor laser. Furthermore, the shape of the laser beam during laser irradiation can be either circular or square.

[0440] Furthermore, examples of materials containing the above-mentioned resins include polyester, polyolefin, and poly Amides (nylon, aramid, etc.), polyimides, polycarbonates, or acrylics, urethanes Tungsten and epoxy can be used. Also, materials containing resins with siloxane bonds can be used. It can be used.

[0441] Furthermore, either one or both of the first sealing region 3007 and the second sealing region 3009 may be used. When using a material containing glass, the thermal expansion coefficient between the glass-containing material and the substrate 3001 It is preferable that they are close together. With the above configuration, the material containing glass or base will be affected by thermal stress. This can prevent cracks from forming in plate 3001.

[0442] For example, a material containing glass is used in the first sealing region 3007, and the second sealing region 3009 When using a material containing resin, the following excellent effects are obtained.

[0443] The second sealing region 3009 extends further outward than the first sealing region 3007 of the light-emitting device 3000. It is located on the side closer to the part. The light-emitting device 3000 is distorted by external forces, etc., as it moves towards the outer circumference. The distortion increases. Therefore, the outer periphery side of the light-emitting device 3000, i.e., the second side, becomes more distorted. The sealing region 3009 is sealed with a resin-containing material, and the second sealing region 3009 is By sealing the first sealing region 3007 provided on the inside with a material including glass, The light-emitting device 3000 becomes less prone to damage even when subjected to external forces or other distortions.

[0444] Furthermore, as shown in Figure 25(B), substrate 3001, substrate 3003, first sealing region 30 In the region surrounded by 07 and the second sealing region 3009, the first region 3011 is formed. Furthermore, substrate 3001, substrate 3003, light-emitting element 3005, and the first sealing region 300 A second region 3013 is formed in the area enclosed by 7.

[0445] The first region 3011 and the second region 3013 are, for example, noble gases or nitrogen gases. It is preferable that the area is filled with an inert gas such as the first region 3011 and the second region For 3013, a reduced pressure state is preferable to an atmospheric pressure state.

[0446] Furthermore, a modified example of the configuration shown in Figure 25(B) is shown in Figure 25(C). Figure 25(C) shows the light emission. This is a cross-sectional view showing a modified example of the apparatus 3000.

[0447] Figure 25(C) shows a recess provided in a part of the substrate 3003, with a desiccant 3018 placed in the recess. This is the configuration. The rest of the configuration is the same as that shown in Figure 25(B).

[0448] Desiccant 3018 is a substance that adsorbs moisture, etc., by chemical adsorption, or by physical adsorption. Therefore, a substance that adsorbs moisture, etc., can be used. For example, it can be used as a desiccant 3018. Substances that can be converted include alkali metal oxides and alkaline earth metal oxides (oxidation). Calcium, barium oxide, etc.), sulfates, metal halides, perchlorates, zeolites, Examples include silica gel.

[0449] Next, regarding a modified example of the light-emitting device 3000 shown in Figure 25(B), see Figures 26(A)(B)( We will explain using C)(D). Note that Figures 26(A)(B)(C)(D) are the same as Figure 25(B). This is a cross-sectional view illustrating a modified example of the light-emitting device 3000 shown.

[0450] The light-emitting device shown in Figures 26(A), (B), (C), and (D) does not have a second sealing region 3009. This configuration includes a first sealing region 3007. Also, see Figure 26(A)(B)(C)(D) The light-emitting device shown has region 3014 instead of the second region 3013 shown in Figure 25(B). do.

[0451] Examples of materials in area 3014 include polyester, polyolefin, and polyamide (nylon Polyimide, polycarbonate or acrylic, urethane, epoxy (e.g., aramid), polyimide, polycarbonate, acrylic, urethane, epoxy It is possible to use materials containing resins having siloxane bonds. Cut.

[0452] Region 3014, by using the materials described above, is made into a so-called solid-encapsulated light-emitting device. It is possible.

[0453] Furthermore, the light-emitting device shown in Figure 26(B) is on the substrate 3001 side of the light-emitting device shown in Figure 26(A). The configuration involves providing a substrate 3015.

[0454] The substrate 3015 has irregularities as shown in Figure 26(B). By providing this on the side from which the light-emitting element 3005 is extracted, the light-emitting element 3005 This can improve the efficiency of light extraction. Furthermore, the uneven surface shown in Figure 26(B) Instead of having a structure, a substrate that functions as a diffuser may be provided.

[0455] Furthermore, the light-emitting device shown in Figure 26(C) is the same as the light-emitting device shown in Figure 26(A) on the substrate 3001 side. While the previous structure extracted light from one side, this structure extracts light from the substrate 3003 side.

[0456] The light-emitting device shown in Figure 26(C) has substrate 3015 on the substrate 3003 side. The configuration is the same as that of the light-emitting device shown in Figure 26(B).

[0457] Furthermore, the light-emitting device shown in Figure 26(D) is the substrate 3003 of the light-emitting device shown in Figure 26(C), This configuration involves providing substrate 3016 without providing 3015.

[0458] The substrate 3016 has a first uneven surface located near the light-emitting element 3005, and the light-emitting element 300 It has a second uneven surface located on the far side of 5. By using the configuration shown in Figure 26(D), The efficiency of light extraction from the light-emitting element 3005 can be further improved.

[0459] Therefore, by implementing the configuration shown in this embodiment, impurities such as water and oxygen can be eliminated. This makes it possible to realize a light-emitting device in which the degradation of the light-emitting element is suppressed. Alternatively, this implementation By implementing the configuration shown in the image, it is possible to realize a light-emitting device with high light extraction efficiency. Cut.

[0460] The configuration shown in this embodiment may be appropriately combined with the configurations shown in other embodiments. It is possible.

[0461] (Embodiment 9) In this embodiment, a light-emitting element according to one aspect of the present invention is applied to various lighting devices and electronic devices. An example of this will be explained using Figures 27 and 28.

[0462] A light-emitting element according to one aspect of the present invention is fabricated on a flexible substrate, thereby having a curved surface. This enables the realization of electronic devices and lighting devices that have a light-emitting region.

[0463] Furthermore, a light-emitting device to which one aspect of the present invention is applied can also be applied to the lighting of automobiles. For example, lighting can be installed on the dashboard, windshield, ceiling, etc.

[0464] Figure 27(A) shows a perspective view of one side of the multi-function terminal 3500, and Figure 27(B) shows a multi This shows a perspective view of the other side of the functional terminal 3500. The multifunctional terminal 3500 is housed in a casing 350. The display unit 3504, camera 3506, lighting 3508, etc. are incorporated into 2. The light-emitting device of the form can be used for illumination 3508.

[0465] The illumination 3508 functions as a surface light source by using a light-emitting device according to one aspect of the present invention. Therefore, unlike point light sources such as LEDs, it is possible to obtain light emission with less directionality. When using the lighting 3508 and camera 3506 in combination, the lighting 3508 is turned on. Alternatively, it can be made to blink and imaged by camera 3506. The illumination 3508 is as follows: Because it functions as a surface light source, it can take photos that look like they were taken under natural light. Cut.

[0466] Note that the multi-function terminal 3500 shown in Figures 27(A) and (B) is the same as shown in Figures 24(A) to 24( Similar to the electronic devices shown in G), they can have a variety of functions.

[0467] Furthermore, inside the housing 3502 are a speaker and sensors (force, displacement, position, velocity, acceleration, angle). Speed, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, electric current, Includes functions for measuring voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. It can have a microphone, etc. Also, inside the multifunction terminal 3500, By providing a detection device that has sensors for detecting tilt, such as gyroscopes and accelerometers, The orientation (portrait or landscape) of the functional terminal 3500 is determined, and the screen display of the display unit 3504 is automatically adjusted. It can be made to switch between modes.

[0468] The display unit 3504 can also function as an image sensor. For example, the display unit 3 By touching the 504 with their palm or fingers, the user can be authenticated by capturing images of their palm print, fingerprints, etc. Furthermore, the display unit 3504 is equipped with a backlight that emits near-infrared light or a sensor that emits near-infrared light. By using a light source for imaging, it is also possible to image finger veins, palmar veins, etc. Note that the display unit 35 A light-emitting device according to one aspect of the present invention may be applied to 04.

[0469] Figure 27(C) shows a perspective view of the security light 3600. The light 3600 is, The housing 3602 has lighting 3608 on its exterior, and the housing 3602 incorporates a speaker 3610, etc. It is incorporated. A light-emitting device according to one aspect of the present invention can be used for illumination 3608.

[0470] Light 3600, for example, grips, grasps, or holds Light 3608. It can emit light by doing so. Also, inside the housing 3602, from light 3600 The device may also include an electronic circuit capable of controlling the method of light emission. For example, the electronic circuit may be one Alternatively, the circuit may be designed to emit light intermittently multiple times, or the current value of the light emission may be controlled. This may result in a circuit that allows the amount of light emitted to be adjusted. Also, the light emitted from the lighting 3608 and At the same time, you could incorporate a circuit that outputs a loud alarm sound from speaker 3610. stomach.

[0471] As for the Light 3600, it can emit light in any direction, so for example, against an assailant It can be used to intimidate with light, or light and sound, directed towards the target. Additionally, the Light 3600 has digital... It may also be equipped with a camera or other camera-related functions that allow for shooting.

[0472] Figure 28 shows an example in which a light-emitting element is used as an indoor lighting device 8501. Because it can be scaled up to cover a large area, it can also be used to form large-area lighting devices. In addition, curved surfaces By using a housing having the above characteristics, a lighting device 8502 having a curved surface in the light-emitting area can be formed. This is also possible. The light-emitting element shown in this embodiment is a thin film, which allows for a high degree of freedom in the design of the housing. Therefore, lighting devices with various elaborate designs can be created. Furthermore, indoor A large lighting fixture 8503 may be installed on the wall. Also, lighting fixtures 8501, 8502, 8 A touch sensor may be provided in 503 to turn the power on or off.

[0473] Furthermore, by using the light-emitting element on the surface side of the table, it is equipped with the functionality of a table. It can be a lighting device 8504. Furthermore, light-emitting elements can be used in other parts of the furniture. This allows for the creation of a lighting device that also functions as furniture.

[0474] As described above, a lighting device and an electronic device are obtained by applying a light-emitting device according to one aspect of the present invention. This is possible. The applicable lighting devices and electronic equipment are those shown in this embodiment. It is applicable to lighting devices and electronic equipment in all fields, not just limited to those areas.

[0475] Furthermore, the configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there. [Examples]

[0476] This embodiment shows an example of the fabrication of a light-emitting element according to one aspect of the present invention. The schematic cross-sectional view of the optical element is the same as that of the light-emitting element 250 shown in Figure 1(A). Details of the element structure This is shown in Table 1. The structures and abbreviations of the compounds used in this example are shown below.

[0477] [ka]

[0478] [ka]

[0479] [Table 1]

[0480] <Fabrication of light-emitting element 1> An ITSO film was formed on the substrate as electrode 101, with a thickness of 110 nm. The electrode area of ​​electrode 101 is 4 mm². 2 (2mm x 2mm)

[0481] Next, an EL layer 100 was formed on the electrode 101. The hole injection layer 111 was made of 1,3, 5-tri(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II) and oxidation The weight ratio (DBT3P-II:MoO3) of molybdenum (MoO3) becomes 1:0.5. Co-deposited so that the thickness was 20 nm. Also, as for the hole transport layer 112 , 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated) A layer (named BPAFLP) was deposited to a thickness of 20 nm.

[0482] Next, the light-emitting layer 130 is 4,6-bis[3-(9H-carbazole-9-yl) Phenylpyrimidine (abbreviation: 4,6mCzP2Pm), 9-phenyl-9'-(trif Enilen-2-yl)-3,3'-bi-9H-carbazole (abbreviation: PCCzTp), Rubrene (also called rubrene) is used in a weight ratio of 4,6 mCzP2Pm:PCCzT The ratio of p (Rubrene) to be 0.8:0.2:0.01, and the thickness to be 40 nm. Co-deposition was carried out in such a manner. In addition, 4,6mCzP2Pm and PC were used in the light-emitting layer 130. CzTp is the host material 131, and Rubrene is the guest material 132 (fluorescent material). be.

[0483] Furthermore, on the light-emitting layer 130, an electron transport layer 118 made of 4,6 mCzP2Pm with a thickness of 2 Next, the electrons were deposited sequentially to a thickness of 0 nm, and then BPhen to a thickness of 10 nm. As the sub-injection layer 119, lithium fluoride (LiF) was deposited to a thickness of 1 nm. .

[0484] Furthermore, the electrode 102 is made of aluminum (Al) shaped to have a thickness of 200 nm. I did it.

[0485] Next, in a glove box under a nitrogen atmosphere, an organic EL sealing material is used to perform EL The light-emitting element 1 was sealed by fixing the sealing substrate to the substrate on which layer 100 was formed. Specifically This involves applying a sealing material around the EL layer 100 formed on the substrate, and then bonding the substrate and the sealing substrate together. In addition, ultraviolet light with a wavelength of 365 nm is emitted at 6 J / cm². 2 Irradiated and heat-treated at 80°C for 1 hour. The light-emitting element 1 was obtained through the above process.

[0486] <Fabrication of light-emitting elements 2 to 4> The light-emitting elements 2 to 4 are made using the same method as the light-emitting element 1 described above, but differ only in the host material of the light-emitting layer 130. The remaining steps were carried out using the same manufacturing method as for the light-emitting element 1.

[0487] The light-emitting layer 130 of the light-emitting element 2 is 4,6mCzP2Pm, N-(1,1'-biphosphate). Nyl-4-yl)-N-[4-(dibenzofuran-4-yl)phenyl]-9,9-dimethyl Tyl-9H-fluoren-2-amine (abbreviation: FrBBiF-II), and Rubre The weight ratio of ne (4,6mCzP2Pm:FrBBiF-II:Rubrene) is 0.8 Co-deposition was performed so that the ratio was 0.2:0.01 and the thickness was 40 nm. In the light-emitting layer 130, 4,6mCzP2Pm and FrBBiF-II are present in the host material 1 The result is 31, and Rubrene is guest material 132 (fluorescent material).

[0488] The light-emitting layer 130 of the light-emitting element 3 is 4,6mCzP2Pm, N-(1,1'-biphosphate). Nyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)pheny [Lu]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), and The weight ratio of Rubrene is (4,6 mCzP2Pm:PCBBiF:Rubrene) Co-depositing was performed to achieve a ratio of 0.8:0.2:0.01 and a thickness of 40 nm. In addition, in the light-emitting layer 130, 4,6mCzP2Pm and PCBBiF are host material 1 The result is 31, and Rubrene is guest material 132 (fluorescent material).

[0489] The light-emitting layer 130 of the light-emitting element 4 is 4,6mCzP2Pm, N-(4-biphenyl) -N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-cal Bazole-3-amine (abbreviation: PCBiF) and Rubrene in a weight ratio of (4,6m) (CzP2Pm:PCBiF:Rubrene) should be set to 0.8:0.2:0.01 Furthermore, the co-deposited layer was made to have a thickness of 40 nm. In addition, in the light-emitting layer 130, 4,6 m CzP2Pm and PCBiF are host materials 131, and Rubrene is the guest material. It is 132 (fluorescent material).

[0490] <Operating characteristics of light-emitting elements 1> Next, the light emission characteristics of the fabricated light-emitting elements 1 to 4 were measured. The experiment was conducted at room temperature (maintained at 23°C).

[0491] Here, 1000 cd / m² 2 The light emission characteristics of the light-emitting elements in the vicinity are shown in Table 2 below. Furthermore, the current efficiency-luminance characteristics of the light-emitting element are shown in Figure 29, and the external quantum efficiency-luminance characteristics are shown in Figure 30. The temperature-voltage characteristics are shown in Figure 31. Furthermore, the light-emitting element has a current of 2.5 mA / cm². 2 Current at this current density Figure 32 shows the field emission spectrum when the solution is flowed.

[0492] [Table 2]

[0493] As shown in Figure 32, the electroluminescence spectral peaks of light-emitting elements 1 to 4 are as follows: Only the yellow emission exhibited by the fluorescent material Rubrene was observed.

[0494] Furthermore, as shown in Figures 29, 30, and Table 2, light-emitting elements 1 to 4 are high current Results demonstrating efficiency and external quantum efficiency were obtained. In particular, the light-emitting element 4 achieved 1000 cd. / m 2In the vicinity, results were obtained showing an external quantum efficiency higher than 8%.

[0495] Singlet generated by the recombination of carriers (holes and electrons) injected from a pair of electrodes. Since the exciton generation probability is a maximum of 25%, if the light extraction efficiency to the outside is set to 20% The combined external quantum efficiency is a maximum of 5%. In light-emitting elements 1 to 4, the external quantity The efficiency is higher than 5%. This is because in light-emitting elements 1 to 4 This is a single layer generated by the recombination of carriers (holes and electrons) injected from a pair of electrodes. In addition to the emission originating from no-term excitons, ExEF generates singlet excitons from triplet excitons. This is because the light emission originates from excitons.

[0496] Furthermore, as shown in Figure 31 and Table 2, the light-emitting elements 1 to 4 are driven at a low voltage. In other words, by having a light-emitting layer using ExEF, a light-emitting element can be driven at a low voltage. Results were obtained showing that it is possible to fabricate such a device. Furthermore, it is possible to fabricate a light-emitting element with reduced power consumption. The results obtained showed that this was possible.

[0497] Next, in order to investigate whether light-emitting elements 1 to 4 are emitting light due to ExEF, Light-emitting elements without the stoichiometric material 132 were fabricated and measured. The details of the element structure are shown in Table 3. show.

[0498] [Table 3]

[0499] <Fabrication of light-emitting elements 5 to 8> The light-emitting elements 5 to 8 are each made using the same process as the light-emitting elements 1 to 4 described above, and the light-emitting layer 130 The only difference is that it does not have the stock material 132; the other steps are performed by the light-emitting elements 1 to 4 respectively. The same manufacturing method was used.

[0500] The light-emitting layer 130 of the light-emitting element 5 is composed of 4,6 mCzP2Pm and PCCzTp by weight. The ratio (4,6mCzP2Pm:PCCzTp) is 0.8:0.2, and the thickness is Co-deposited to a wavelength of 40 nm. Note that in the light-emitting layer 130, 4,6 mCzP2Pm Furthermore, PCCzTp corresponds to the host material 131 and does not have the guest material 132.

[0501] The light-emitting layer 130 of the light-emitting element 6 is made of 4,6mCzP2Pm and FrBBiF-II The weight ratio (4,6mCzP2Pm:FrBBiF-II) is set to 0.8:0.2. Furthermore, the co-deposited layer was made to have a thickness of 40 nm. In addition, in the light-emitting layer 130, 4,6 m CzP2Pm and FrBBiF-II correspond to host material 131, and guest material 132 It does not possess.

[0502] The light-emitting layer 130 of the light-emitting element 7 is composed of 4,6mCzP2Pm and PCBBiF by weight. The ratio (4,6mCzP2Pm:PCBBiF) is 0.8:0.2, and the thickness is Co-deposited to a wavelength of 40 nm. Note that in the light-emitting layer 130, 4,6 mCzP2Pm Furthermore, PCBBiF corresponds to the host material 131 and does not have a guest material 132.

[0503] The light-emitting layer 130 of the light-emitting element 8 is composed of 4,6mCzP2Pm and PCBiF in a weight ratio. (4,6mCzP2Pm:PCBiF) is set to 0.8:0.2, and the thickness is 40 Co-deposited to achieve nm. In addition, in the emissive layer 130, 4,6 mCzP2Pm and The PCBiF corresponds to the host material 131 and does not have the guest material 132.

[0504] <Operating characteristics of light-emitting elements 2> Next, the light emission characteristics of the fabricated light-emitting elements 5 to 8 were measured. The measurements were taken at room temperature (2 The experiment was conducted in an environment maintained at 3°C.

[0505] Here, 1000 cd / m² 2 The light emission characteristics of the light-emitting elements in the vicinity are shown in Table 4 below. Furthermore, the current efficiency-luminance characteristics of the light-emitting element are shown in Figure 33, and the external quantum efficiency-luminance characteristics are shown in Figure 34. The temperature-voltage characteristics are shown in Figure 35. Additionally, the light-emitting element has a current of 2.5 mA / cm². 2 Current at this current density Figure 36 shows the electroluminescence spectrum when the solution is flowed.

[0506] [Table 4]

[0507] Also, Figure 37 shows the host materials used: 4,6mCzP2Pm, PCCzTp, Fr The emission spectra of thin films of BBiF-II, PCBBiF, and PCBiF are shown. For measuring the emission spectrum of thin films, a PL-EL measuring device (manufactured by Hamamatsu Photonics) is used. I used it.

[0508] As shown in Figure 37, the host materials used were 4,6mCzP2Pm, PCCzTp, FrBBiF-II, PCBBiF, and PCBiF each have peak wavelengths of 49 Blue emission was observed at 3nm, 418nm, 428nm, 436nm, and 430nm.

[0509] On the other hand, as shown in Figure 36, light-emitting element 5, light-emitting element 6, light-emitting element 7, and light-emitting element 8 From the electroluminescence spectrum peaks, the peak wavelengths were determined to be 499 nm, 513 nm, and 53 nm, respectively. Green to yellow emission was observed at 6 nm and 552 nm, and the full width at half maximum of the emission spectrum was In all cases, the emission spectra were larger than those of the individual compounds. (Emitting element 5 to emission element) The wavelengths of the emission spectrum of sub-sub HOMO level, LUMO level of 4,6mCzP2Pm and HOMO level of FrBBiF-II The LUMO levels of 4,6mCzP2Pm and PCBBiF, and the HOMO level of 4,6m The energy difference between the LUMO level of CzP2Pm and the HOMO level of PCBiF is as follows: Because of the correlation, 4,6mCzP2Pm and PCCzTp, and 4,6mCzP2Pm and FrB BiF-II, 4.6mCzP2Pm and PCBBiF, and 4.6mCzP2Pm and PC This can be attributed to the luminescence exhibited by the excited complex with BiF.

[0510] Furthermore, Figure 38 shows the Rubren used as the guest material for light-emitting elements 1 to 4. The absorption spectrum of a toluene solution containing e is shown.

[0511] As shown in Figure 38, the absorption spectrum of Rubrene is from 450 nm to 550 nm. It has an absorption band with a high molar extinction coefficient nearby. This is the electric field of the excited complex shown in Figure 36. The results are in good agreement with the wavelength range of the emission spectrum. Therefore, the light-emitting element 1 By using a compound combination that forms an excited complex as the host material for the light-emitting element 4, It was found to be suitable because it increases the energy transfer efficiency to the guest material.

[0512] Furthermore, as shown in Figures 33, 34, and Table 4, the light-emitting elements 7 and 8 emit high light. Results demonstrating efficiency (current efficiency and external quantum efficiency) were obtained. In particular, the light-emitting element 8 The results showed minimal decrease in luminous efficiency (roll-off) even at high brightness levels.

[0513] 1000 cd / m² 2 In the vicinity, the luminous efficiency of light-emitting element 5 and light-emitting element 6 is roughly the same. Furthermore, the light-emitting element 7 has a higher luminous efficiency than the light-emitting elements 5 and 6, and the light-emitting element 8 is higher than the light-emitting element 7. High luminescence efficiency was obtained. Furthermore, in the light-emitting elements 1 to 4 shown above... is 1000 cd / m² 2 In the vicinity, the luminous efficiency of light-emitting element 1 and light-emitting element 2 are roughly the same. The light-emitting element 3 has a higher luminous efficiency than light-emitting elements 1 and 2, and the light-emitting element 4 has a higher luminous efficiency than light-emitting element 3. A result with higher luminescence efficiency was obtained.

[0514] In other words, the luminescence efficiency of the emission exhibited by the excited complex and the luminescence efficiency of the emission exhibited by the guest material are A correlational result was obtained. The high luminescence efficiency of the excited complex indicates that in the excited complex This means that the rate constant for non-radiative deactivation is small, suggesting that the rate constant for inverse intersystem crossing is large. It will be done.

[0515] Next, a time-resolved fluorescent light was applied to a thin film equivalent to the light-emitting layer of light-emitting elements 5 to 8. Light measurements were performed.

[0516] <Preparation of thin film samples> To perform time-resolved fluorescence measurements of the light-emitting layer of a light-emitting element, a thin film is deposited onto a quartz substrate using vacuum deposition. A sample was prepared.

[0517] Thin film 1 consists of 4,6mCzP2Pm and FrBBiF-II in a weight ratio (4,6m The ratio of CzP2Pm:FrBBiF-II is 0.8:0.2, and the thickness is 50n. Co-deposited to form m.

[0518] Thin film 2 consists of 4,6mCzP2Pm and PCBBiF in a weight ratio (4,6mCzP The ratio of 2Pm:PCBBiF is 0.8:0.2, and the thickness is 50nm. It was co-deposited.

[0519] Thin film 3 consists of 4,6mCzP2Pm and PCBiF in a weight ratio (4,6mCzP2 The Pm:PCBiF ratio is set to 0.8:0.2, and the thickness is set to 50 nm. It was vapor-deposited.

[0520] Furthermore, in a glove box under a nitrogen atmosphere, a thin film was created using an organic EL sealing material. By fixing the sealing substrate onto the quartz substrate on which the sample film has been deposited, thin films 1 to 3 are each Specifically, a sealing material was applied around a thin film formed on a quartz substrate, and the quartz substrate was sealed. The board and the encapsulated substrate are bonded together, and ultraviolet light with a wavelength of 365 nm is applied at 6 J / cm². 2 Irradiate and heat to 80°C It was then heat-treated for 1 hour.

[0521] <Time-resolved fluorescence measurement of thin film samples> A picosecond fluorescence lifetime measurement system (manufactured by Hamamatsu Photonics) was used for the measurement. In this measurement, To measure the lifetime of fluorescence emission exhibited by a thin film, the thin film is irradiated with a pulsed laser. The light emission, which decays over time, was measured with time-resolved data using a streak camera. A nitrogen gas laser with a wavelength of 337 nm is used, and a 500 ps pulsed laser is applied at a frequency of 10 Hz. By irradiating a thin film for a period of time and integrating the repeatedly measured data, a data with a high signal-to-noise ratio can be obtained. We obtained a result. The measurement was also performed at room temperature (in an atmosphere maintained at 23°C).

[0522] From thin films 1 to 3, the luminescence exhibited by the excited complexes formed by the two compounds can be observed. The measurement was taken. The damping curve obtained from the measurement is shown in Figure 39.

[0523] Furthermore, the damping curve shown in Figure 39 was fitted using the following formula (4). .

[0524]

number

[0525] In equation (4), L represents the normalized luminescence intensity, and t represents the elapsed time. Attenuation curve As a result of the fitting, we were able to perform fitting for n = 1 and n = 2. From the fitting results of the decay curve, the luminescence component of thin film 1 has a rapid fluorescence lifetime of 0.60 μs. The fluorescence component (including the prompt component) and the delayed fluorescence component (delayed component) with a 96 μs delay It was found that the luminescence component of thin film 2 contains (also called a fraction). It was found that the fluorescence contained both a fast fluorescence component of 0.72 μs and a delayed fluorescence component of 55 μs. On the other hand, the light-emitting component of thin film 3 includes a fast-fluorescent component with a fluorescence lifetime of 0.67 μs and a component with a fluorescence lifetime of 23 μs. It was found to contain a delayed fluorescence component. In other words, it was a light-emitting element that yielded high luminescence efficiency. The delayed fluorescence lifetime of the excitation complex used in sub-4 and light-emitting element 8 is the same as that of the other light-emitting elements 2 and 3. Shorter than the delayed fluorescence lifetime of the excitation complex used in the photonic element 6 and the light-emitting element 7, and less than 50 μs. It was found that there is such a component. Furthermore, the proportion of the luminescence accounted for by this delayed fluorescence component is in thin film 1 to thin film 3. The calculated percentages were 0.084%, 3.8%, and 9.4%, respectively.

[0526] As described above, thin film 3 has a delayed fluorescence component with a relatively short fluorescence lifetime. It was found that a short lifetime of the delayed fluorescence component indicates a fast rate constant for inverse intersystem crossing. This suggests that the results obtained by the light-emitting element 8 support the result. Furthermore, the triplet excitons of the excited complex are converted to singlet excitons in a relatively short time, resulting in high brightness. Even in the high-exciton-density region, saturation of the exciton density did not occur, so light emission occurred. Element 8 can be said to have shown that it is less prone to a decrease in luminous efficiency in the high-brightness region. Comparing elements 1 to 4, element 3 (delayed fluorescence in time-resolved fluorescence measurement of excitation complex) Although the lifespan is 55 μs, the luminous efficiency is improved compared to light-emitting elements 1 and 2. The significant improvement in luminescence efficiency is observed in light-emitting element 4 (in the time-resolved fluorescence measurement of the excitation complex). The fluorescence lifetime is 23 μs. In other words, in one embodiment of the present invention, the time of the excitation complex Preferably, the delayed fluorescence lifetime in the defluorescence measurement is 50 μs or less, and more preferably... The interval is 40 μs or less, more preferably 30 μs or less.

[0527] Furthermore, in time-resolved fluorescence measurements, thin film 3 exhibits a delayed fluorescence component of 5% or less of the emitted light. Since the above is included, there is a relatively high probability that energy transfer occurs between the singlet excited state and the triplet excited state. This suggests that it is occurring there.

[0528] Furthermore, a light-emitting element 4 has an excitation complex with a short-lived delayed fluorescence component as a host material. The results show high luminescence efficiency. This is because the triplet excitons of the excited complex are relatively By being converted to singlet excitons in a short time, the triplet excited state of the excited complex becomes a guest material. To reduce the energy transfer efficiency to the triplet excited state, in excited complexes and guest materials This is because we were able to improve the efficiency of singlet exciton generation.

[0529] As described above, the host material has a compound that forms an excited complex, and the excited complex is 50 It must contain at least 5% delayed fluorescence components with a relatively short fluorescence lifetime of less than 1 / 2 μs. Therefore, it was found that it is possible to fabricate a light-emitting element that exhibits high luminescence efficiency, as shown in light-emitting element 4.

[0530] The configuration shown in this embodiment can be used in appropriate combination with other embodiments. . [Explanation of Symbols]

[0531] 100 EL layer 101 Electrode 101a Conductive layer 101b Conductive layer 101c conductive layer 102 electrode 103 Electrode 103a Conductive layer 103b Conductive layer 104 Electrode 104a conductive layer 104b Conductive layer 106 Light-emitting unit 108 Light-emitting units 111 Hole injection layer 112 Hole transport layer 113 Electron transport layer 114 Electron injection layer 115 Charge generation layer 116 Hole injection layer 117 Hole transport layer 118 Electron transport layer 119 Electron injection layer 120 Emitting layer 121 Host Materials 122 Guest Materials 123B Emitting layer 123G emissive layer 123R emissive layer 130 Emitting layer 131 Host Materials 131_1 Organic compounds 131_2 Organic compounds 132 Guest Materials 140 Emitting layer 141 Host Materials 141_1 Organic compounds 141_2 Organic compounds 142 Guest Materials 145 Bulkhead 150 Emitting layer 150a Light-emitting layer 150b Emitting layer 200 circuit boards 220 circuit boards 221B area 221G area 221R area 222B area 222G area 222R area 223 Light blocking layer 224B Optical element 224G optical chip 224R optical element 250 light-emitting elements 260 light-emitting elements 262 Light-emitting element 270a Light-emitting element 270b Light-emitting element 272a Light-emitting element 272b Light-emitting element 301_1 Wiring 301_5 Wiring 301_6 Wiring 301_7 Wiring 302_1 Wiring 302_2 Wiring 303_1 Transistor 303_6 Transistor 303_7 Transistor 304 Capacitive element 304_1 Capacitive element 304_2 Capacitive element 305 Light-emitting element 306_1 Wiring 306_3 Wiring 307_1 Wiring 307_3 Wiring 308_1 Transistor 308_6 Transistor 309_1 Transistor 309_2 Transistor 311_1 Wiring 311_3 Wiring 312_1 Wiring 312_2 Wiring 600 display device 601 Signal Line Drive Circuit Section 602 pixel section 603 Scan Line Drive Circuit Section 604 Sealing substrate 605 Sealant 607 area 608 Wiring 609 FPC 610 element substrate 611 transistors 612 transistors 613 Lower electrode 614 Bulkhead 616 EL layer 617 Upper electrode 618 Light-emitting element 621 Optical elements 622 Light blocking layer 623 Transistors 624 transistors 801 Pixel Circuit 802 pixel section 804 Drive Circuit Section 804a Scan line drive circuit 804b Signal line drive circuit 806 protection circuit 807 Terminal section 852 transistors 854 transistors 862 Capacitive elements 872 Light-emitting element 1001 circuit board 1002 Underlying insulating film 1003 Gate Insulator 10:06 Guard Station 1007 🙏 1008 Gate 1020 Interlayer insulating film 1021 Interlayer insulating film 1022 electrode 1024B Lower electrode 1024G bottom electrode 1024R lower electrode 1024Y lower electrode 1025 Bulkhead 1026 Upper electrode 1028 EL layer 1029 Sealing layer 1031 Sealing substrate 1032 Sealant 1033 Base material 1034B Colored layer 1034G colored layer 1034R colored layer 1034Y colored layer 1035 Light blocking layer 1036 Overcoat layer 1037 Interlayer insulating film 1040 pixel section 1041 Drive circuit section 1042 Peripheral area 2000 Touch Panel 2001 Touch Panel 2501 Display device 2502R pixels 2502t Transistor 2503c Capacitive element 2503g Scan line drive circuit 2503s Signal Line Drive Circuit 2503t Transistor 2509 FPC 2510 circuit board 2510a Insulating layer 2510b flexible substrate 2510c adhesive layer 2511 Wiring 2519 terminal 2521 Insulating layer 2528 Bulkhead 2550R Light-emitting element 2560 Sealing layer 2567BM light shielding layer 2567p anti-reflection layer 2567R colored layer 2570 circuit board 2570a Insulating layer 2570b flexible substrate 2570c adhesive layer 2580R Light-Emitting Module 2590 circuit board 2591 Electrode 2592 Electrode 2593 Insulating layer 2594 Wiring 2595 Touch Sensor 2597 Adhesive layer 2598 Wiring 2599 Connectivity Layer 2601 Pulse voltage output circuit 2602 Current detection circuit 2603 Capacity 2611 Transistors 2612 transistors 2613 Transistors 2621 Electrode 2622 Electrode 3000 Light-emitting devices 3001 circuit board 3003 circuit board 3005 Light-emitting element 3007 Sealing area 3009 Sealing area 3011 area 3013 area 3014 area 3015 circuit board 3016 circuit board 3018 Desiccant 3500 Multifunctional Terminals 3502 enclosure 3504 Display section 3506 Camera 3508 Lighting 3600 Lights 3602 enclosure 3608 Lighting 3610 speaker 8000 Display Module 8001 Top cover 8002 Lower cover 8003 FPC 8004 Touch Sensor 8005 FPC 8006 Display device 8009 Frame 8010 Printed Circuit Board 8011 Battery 8501 Lighting device 8502 Lighting device 8503 Lighting device 8504 Lighting device 9000 cabinets 9001 Display section 9003 Speaker 9005 Operation Keys 9006 Connection terminal 9007 Sensor 9008 Microphone 9050 Operation Buttons 9051 Information 9052 Information 9053 Information 9054 Information 9055 Hinge 9100 Mobile Information Terminal 9101 Mobile Information Terminal 9102 Mobile Information Terminal 9200 Mobile Information Terminal 9201 Mobile Information Terminal

Claims

1. Between a pair of electrodes, there is a first light-emitting layer, a second light-emitting layer, and a charge-generating layer. The charge generation layer is located between the first light-emitting layer and the second light-emitting layer. The charge generation layer has a configuration having a hole-transporting material and an acceptor material, a configuration having an electron-transporting material and a donor material, or a configuration in which a layer having a hole-transporting material and an acceptor material and a layer having an electron-transporting material and a donor material are laminated together. The first light-emitting layer of the present invention comprises a first organic compound and a first fluorescent light-emitting material. The T1 level of the first organic compound is lower than the T1 level of the first fluorescent material. The S1 level of the first organic compound is higher than the S1 level of the first fluorescent material. The second light-emitting layer comprises a thermally activated delayed fluorescence material having a delayed fluorescence component with a fluorescence lifetime of 10 ns to 50 μs, and exhibiting emission in which the proportion of the delayed fluorescence component is 5% or more, and a second fluorescent light-emitting material. The S1 level of the thermally activated delayed fluorescence material is higher than the S1 level of the second fluorescence emission material. The emission spectrum of the thermally activated delayed fluorescence material overlaps with the longest wavelength absorption band of the absorption spectrum of the second fluorescence emission material. The thermally activated delayed fluorescence material has the function of supplying excitation energy to the second fluorescence emission material. A light-emitting element that emits light from the first fluorescent material and light from the second fluorescent material.

2. In claim 1, The thermally activated delayed fluorescence material is a heterocyclic compound having a π-electron-rich heteroaromatic ring skeleton and a π-electron-deficient heteroaromatic ring skeleton, which is a light-emitting element.

3. A light-emitting device having a light-emitting element according to claim 1 or claim 2, and a substrate.

4. A display device comprising a light-emitting element according to claim 1 or claim 2, and at least one of a color filter or a transistor.

5. An electronic device comprising the display device described in claim 4 and at least one of a housing or a touch sensor.

6. A lighting device comprising a light-emitting element according to claim 1 or claim 2, and at least one of a housing or a touch sensor.

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