JP6595752B2 - LIGHT EMITTING ELEMENT, LIGHT EMITTING DEVICE, ELECTRONIC DEVICE, AND LIGHTING DEVICE - Google Patents

Description

  One embodiment of the present invention relates to a light-emitting element including a light-emitting layer that can emit light by applying an electric field between a pair of electrodes. In particular, the present invention relates to a light-emitting element having an iridium complex in a light-emitting layer. Further, the present invention relates to a light-emitting device, a display device, an electronic device, and a lighting device each having the light-emitting element.

  Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition (composition of matter). Therefore, the technical field of one embodiment of the present invention disclosed in this specification more specifically includes a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, a driving method thereof, Alternatively, the production method thereof can be given as an example.

  A light-emitting element (also referred to as an organic EL element) including an organic compound that is a light-emitting substance between a pair of electrodes is attracting attention as a next-generation flat panel display because of its characteristics such as thin and light weight, high-speed response, and low-voltage driving. In addition, a display using an organic EL element is characterized by excellent contrast and image quality and a wide viewing angle.

  Various materials have been researched and developed as organic compounds used in organic EL elements. For example, an iridium complex having iridium (Ir) as a central metal attracts attention as an organic compound that is a light-emitting substance.

  For example, Patent Document 1 discloses a tris-type iridium complex in which a ligand having a nitrogen-containing five-membered heterocyclic skeleton is coordinated as an iridium complex capable of exhibiting phosphorescence having a wavelength shorter than that of green. Yes. The iridium complex has a nitrogen-containing five-membered heterocyclic skeleton consisting of 2 to 4 nitrogen and carbon ligands, and in the nitrogen-containing five-membered heterocyclic skeleton, the carbon on which nitrogen is located on both sides is located. An aryl group is bonded to each other, and has a structure in which a tricycloalkyl group having 9 or 10 carbon atoms having a bridging structure is bonded to one of two nitrogens located on both sides of the carbon.

JP 2013-147490 A

  As reported in Patent Document 1, development of guest materials using iridium complexes has been actively conducted. However, when viewed as a light-emitting element, there remains room for improvement in terms of light-emitting efficiency, reliability, light-emitting characteristics, synthesis efficiency, or cost, and development of a more excellent light-emitting element is desired.

  In view of the above problems, one embodiment of the present invention provides a novel light-emitting element. Another object of one embodiment of the present invention is to provide a light-emitting element having an iridium complex in a light-emitting layer. Another object of one embodiment of the present invention is to provide a light-emitting element having an iridium complex in a light-emitting layer and having high emission efficiency. Another object of one embodiment of the present invention is to provide a light-emitting element having an iridium complex in a light-emitting layer and having a spectral peak in a blue wavelength band. Another object is to provide a light-emitting element having a spectral peak in a blue wavelength band and high emission efficiency.

  Another object of one embodiment of the present invention is to provide a light-emitting device, an electronic device, and a lighting device each including the light-emitting element.

  Note that the description of these problems does not disturb the existence of other problems. Note that one embodiment of the present invention does not have to solve all of these problems. Issues other than these will be apparent from the description of the specification, drawings, claims, etc., and other issues can be extracted from the descriptions of the specification, drawings, claims, etc. It is.

  One embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, the light-emitting layer includes an iridium complex, and the iridium complex includes an iridium metal and a ligand coordinated to the iridium metal. The substituent is a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200, and the ligand has a nitrogen-containing five-membered heterocyclic skeleton. .

  Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, the light-emitting layer includes an iridium complex, and the iridium complex is coordinated to the iridium metal and the iridium metal. A ligand and a substituent bonded to the ligand, wherein the substituent is a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200, and the ligand is an imidazole skeleton or a triazole skeleton Have

  Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, and the light-emitting element includes a light-emitting layer and an electron transport layer in contact with the light-emitting layer. The host material and the guest material, the electron transport layer has an electron transport material, the guest material has an iridium complex, and the iridium complex coordinates to the iridium metal and the iridium metal. A ligand and a substituent bonded to the ligand. The substituent is a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200, and the ligand is a nitrogen-containing five-membered complex. It has a ring skeleton, and the difference between the LUMO level of the electron transporting material and the LUMO level of the host material is within 0.3 eV.

  Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, and the light-emitting element includes a light-emitting layer and an electron transport layer in contact with the light-emitting layer. The host material and the guest material, the electron transport layer has an electron transport material, the guest material has an iridium complex, and the iridium complex coordinates to the iridium metal and the iridium metal. A ligand and a substituent bonded to the ligand, wherein the substituent is a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200, and the ligand is an imidazole skeleton or a triazole skeleton And the difference between the LUMO level of the electron transporting material and the LUMO level of the host material is within 0.3 eV.

  Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, and the light-emitting element includes a light-emitting layer and an electron transport layer in contact with the light-emitting layer. The host material and the guest material, the electron transport layer has an electron transport material, both the host material and the electron transport material have a pyridine skeleton or a pyrimidine skeleton, and the guest material is The iridium complex has an iridium metal, a ligand coordinated to the iridium metal, and a substituent bonded to the ligand. The substituent has a mass number of 90 or more and less than 200. A crosslinked cyclic hydrocarbon group.

  Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, and the light-emitting element includes a light-emitting layer and an electron transport layer in contact with the light-emitting layer. The host material and the guest material, the electron transport layer has an electron transport material, both the host material and the electron transport material have a pyridine skeleton or a pyrimidine skeleton, and the guest material is The iridium complex has an iridium metal, a ligand coordinated to the iridium metal, and a substituent bonded to the ligand. The substituent has a mass number of 90 or more and less than 200. And the ligand has an imidazole skeleton or a triazole skeleton.

  In the above embodiment, the substituent is preferably bonded to the nitrogen atom in the ring of the nitrogen-containing five-membered heterocyclic skeleton. In the above embodiment, the substituent is preferably bonded to a ring nitrogen atom of the imidazole skeleton or the triazole skeleton. In the above embodiment, the substituent preferably has an adamantyl group.

  In the above embodiment, the iridium complex preferably has a tris-type structure.

  In the above embodiment, the light emitted from the light emitting layer preferably has an emission spectrum peak in the blue wavelength band.

  In the above embodiment, the iridium complex is preferably represented by the following general formula (G1).

In General Formula (G1), Z represents a C 9 or C 10 tricycloalkyl group having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. Q ¹ and Q ² each independently represent carbon or nitrogen, and when it is carbon, it may have a substituent.

  In the above embodiment, the iridium complex is preferably represented by the following general formula (G2).

In General Formula (G2), Z represents a C 9 or C 10 tricycloalkyl group having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. R ⁵ and R ⁶ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.

  In the above embodiment, the iridium complex is preferably represented by the following general formula (G3).

In General Formula (G3), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. R ⁵ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

  In the above embodiment, the iridium complex is preferably represented by General Formula (G4) below.

In General Formula (G4), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. R ⁶ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

  In the above embodiment, the tricycloalkyl group is preferably represented by the following structural formula (Z1) or (Z2).

  Another embodiment of the present invention is a light-emitting device including the light-emitting element of the above embodiment and a color filter. Another embodiment of the present invention is an electronic device including the light-emitting element or the light-emitting device of the above embodiment and a housing or a touch sensor function. Another embodiment of the present invention is a lighting device including the light-emitting element of the above embodiment or the light-emitting device of the above embodiment, and a housing.

  According to one embodiment of the present invention, a novel light-emitting element can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting element having an iridium complex in a light-emitting layer can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting element having an iridium complex in a light-emitting layer and having high emission efficiency can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting element having an iridium complex in a light-emitting layer and having a spectral peak in a blue wavelength band can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting element having a spectral peak in a blue wavelength band and high emission efficiency can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device, an electronic device, and a lighting device each including the light-emitting element can be provided.

  Note that one embodiment of the present invention is not limited to these effects. For example, one embodiment of the present invention may have effects other than these effects depending on circumstances or circumstances. Alternatively, for example, one embodiment of the present invention may not have these effects depending on circumstances or circumstances.

FIG. 10 is a schematic cross-sectional view illustrating a light-emitting element. The figure explaining spin density distribution of guest material. FIG. 10 is a schematic cross-sectional view illustrating a light-emitting element. 10A and 10B are a block diagram and a circuit diagram illustrating a display device. FIG. 10 is a circuit diagram illustrating a pixel circuit of a display device. FIG. 10 is a circuit diagram illustrating a pixel circuit of a display device. The perspective view which shows an example of a touch panel. Sectional drawing which shows an example of a display panel and a touch sensor. Sectional drawing which shows an example of a touch panel. The block diagram and timing chart figure of a touch sensor. The circuit diagram of a touch sensor. The perspective view explaining a display module. 10A and 10B each illustrate an electronic device. 4A and 4B are a perspective view and a cross-sectional view illustrating a light-emitting device. FIG. 14 is a cross-sectional view illustrating a light-emitting device. FIG. 6 illustrates a lighting device and an electronic device. FIG. 6 is a schematic cross-sectional view illustrating a light-emitting element in an example. 4A and 4B illustrate luminance-current density characteristics of a light-emitting element and luminance-voltage characteristics of the light-emitting element in Examples. 4A and 4B illustrate an external quantum efficiency-luminance characteristic of a light-emitting element and an emission spectrum of the light-emitting element in Examples.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that one embodiment of the present invention is not limited to the following description, and various changes can be made in form and details without departing from the spirit and scope of the present invention. Therefore, one embodiment of the present invention is not construed as being limited to the description of the following embodiments or examples.

  Note that the position, size, range, and the like of each component illustrated in the drawings and the like may not represent the actual position, size, range, or the like for easy understanding. Therefore, one embodiment of the disclosed invention is not necessarily limited to the position, size, range, or the like disclosed in the drawings and the like.

  In the present specification and the like, the ordinal numbers attached as the first and second are used for convenience and do not indicate the order of steps or the order of lamination. Therefore, for example, the description can be made by appropriately replacing “first” with “second” or “third”. In addition, the ordinal numbers described in this specification and the like may not match the ordinal numbers used to specify one embodiment of the present invention.

  Further, in this specification and the like, in describing the structure of the invention with reference to the drawings, the same reference numerals are used in different drawings.

  In this specification and the like, the terms “film” and “layer” can be interchanged with each other. For example, the term “conductive layer” may be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” may be changed to the term “insulating layer” in some cases.

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

<1. Configuration of light emitting element>
FIG. 1 is a cross-sectional view illustrating a light-emitting element of one embodiment of the present invention. The light-emitting element illustrated in FIG. 1 is a light-emitting element including a light-emitting layer between a pair of electrodes and an iridium complex in the light-emitting layer.

  More specifically, the light-emitting element 100 illustrated in FIG. 1 includes an EL layer 108 between a pair of electrodes (a lower electrode 104 and an upper electrode 114). In addition, the EL layer 108 includes a light emitting layer 110. In addition to the light-emitting layer 110, the EL layer 108 includes a hole injection layer 131, a hole transport layer 132, an electron transport layer 133, and an electron injection layer 134.

  In this embodiment mode, the lower electrode 104 is used as an anode and the upper electrode 114 is used as a cathode. The lower electrode 104 is formed on the substrate 102. The light emitting layer 110 contains an iridium complex as a light emitting substance.

  By applying a voltage to the light emitting element 100, holes injected from the lower electrode 104 side and electrons injected from the upper electrode 114 side recombine in the light emitting layer 110 and are included in the light emitting layer 110. The luminescent material is excited. Then, light is emitted when the excited light-emitting substance returns to the ground state.

  Specifically, as illustrated in FIG. 1B, the light-emitting layer 110 includes a host material 121 and a guest material 122. Note that FIG. 1B is a cross-sectional view schematically illustrating the inside of the light-emitting layer 110 illustrated in FIG.

  The host material 121 is present in the light emitting layer 110 in the most weight ratio. In addition, the guest material 122 is dispersed in the host material 121. In addition, the guest material 122 includes an iridium complex as a light-emitting substance. Note that as the host material 121, a substance having a triplet excitation energy level higher than that of the guest material 122 may be used.

  The iridium complex has an iridium metal, a ligand coordinated to the iridium metal, and a substituent that binds to the ligand. The substituent is a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200, and the ligand has a nitrogen-containing five-membered heterocyclic skeleton. As the nitrogen-containing five-membered heterocyclic skeleton, an imidazole skeleton or a triazole skeleton is preferable because of high chemical stability and physical stability. In particular, a triazole skeleton is more preferable because of high luminous efficiency.

  By using the iridium complex described above for the light emitting layer 110, phosphorescence having an emission spectrum peak in the short wavelength side, that is, in the blue wavelength band can be obtained. Phosphorescence emission is light emission from a triplet level that is lower in energy than a singlet excitation level. Therefore, a wide energy gap is required to obtain an emission spectrum peak in the blue wavelength band.

  Typical examples of iridium complexes include bis-type complexes in which two identical ligands are coordinated to iridium metal and tris-type complexes in which three identical ligands are coordinated to iridium metal. It is done. The tris-type complex may be more reliable because it has a more stable structure than the bis-type complex. On the other hand, a tris-type complex needs to coordinate three identical ligands to an iridium metal, so that it may be difficult to synthesize depending on the structure of the ligand. In particular, in the case of an iridium complex having a nitrogen-containing five-membered heterocyclic skeleton as a ligand, depending on the structure of the ligand, the ligand may be decomposed in the process of synthesizing the tris-type complex. The complex may be very difficult to obtain.

  However, in one embodiment of the present invention, the nitrogen five-membered heterocyclic skeleton which is a ligand of an iridium complex has a substituent having a large mass number. Specifically, by having a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200 as a substituent, for example, the ligand is decomposed during synthesis as compared with the case where the substituent is a methyl group or a phenyl group. Can be suppressed. Moreover, as a bridged cyclic hydrocarbon group having a mass number of 90 or more and less than 200, an adamantyl group is preferably used because the structure is rigid.

  For example, as the guest material 122 of the light-emitting layer 110 illustrated in FIGS. 1A and 1B, an iridium complex represented by the following general formula (G1) can be used.

In General Formula (G1), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. Q ¹ and Q ² each independently represent carbon or nitrogen, and when it is carbon, it may have a substituent.

  Alternatively, as the guest material 122 of the light-emitting layer 110 illustrated in FIGS. 1A and 1B, an iridium complex represented by the following general formula (G2) can be used.

In General Formula (G2), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. R ⁵ and R ⁶ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.

  Alternatively, as the guest material 122 of the light-emitting layer 110 illustrated in FIGS. 1A and 1B, an iridium complex represented by General Formula (G3) below can be used.

In General Formula (G3), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. R ⁵ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

  Alternatively, as the guest material 122 of the light-emitting layer 110 illustrated in FIGS. 1A and 1B, an iridium complex represented by General Formula (G4) below can be used.

In General Formula (G4), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. R ⁶ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

  In general formulas (G1) to (G4), Z preferably has a structure represented by the following structural formula (Z1) or (Z2).

<2. Synthesis Method of Iridium Complex Represented by General Formula (G1)>
Next, a method for synthesizing an iridium complex that can be used for the guest material 122 of the light-emitting layer 110 of the light-emitting element 100 of one embodiment of the present invention is described below.

  The iridium complex represented by the general formula (G1) can be synthesized by the following synthesis scheme (a). That is, a nitrogen-containing five-membered ring derivative represented by the general formula (G0) and a compound containing halogen and iridium (such as iridium chloride, iridium bromide, iridium iodide, ammonium hexachloroiridate), or an organic containing iridium An organic metal complex having a structure represented by the general formula (G1) can be obtained by heating after mixing with the metal complex. Further, in this heating process, a nitrogen-containing five-membered ring derivative represented by the general formula (G0) and a compound containing halogen and iridium or an organometallic complex containing iridium are mixed with an alcohol solvent (glycerol, ethylene glycol, 2 -Methoxyethanol, 2-ethoxyethanol, phenol, etc.) may be performed after dissolution, or an appropriate base may be added. There is no particular limitation on the heating means, and an oil bath, a sand bath, or an aluminum block may be used. Moreover, it is also possible to use a microwave as a heating means.

In the synthesis scheme (a), Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. R ^{1 to} R ⁴ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a phenyl group. Q ¹ and Q ² each independently represent carbon or nitrogen, and when it is carbon, it may have a substituent.

  As described above, the iridium complex represented by General Formula (G1) can be synthesized.

<3. Specific examples of iridium complexes>
Specific examples of the iridium complexes represented by the general formulas (G1) to (G4) include iridium complexes represented by the structural formulas (100) to (144) or the structural formulas (200) to (216). It is done. Note that the iridium complex that can be used for the light-emitting element of one embodiment of the present invention is not limited thereto.

  Note that the iridium complex represented by the structural formulas (100) to (144) or the structural formulas (200) to (216) may have a stereoisomer depending on the type of the ligand. The light-emitting element which is one embodiment includes all of these isomers. The iridium complexes represented by the structural formulas (100) to (144) or the structural formulas (200) to (216) are substances that can emit blue phosphorescence.

<4. About Spin Density Distribution of Guest Materials>
Next, the spin density distribution of the iridium complex which is the guest material 122 which is one embodiment of the present invention was calculated using quantum chemical calculation. The iridium complex used in the calculation was tris {2- [4- (1-adamantyl) -3-methyl-4H-1,2,4-triazol-5-yl-κN] phenyl-κC} iridium (III) ( Abbreviations: Ir (Mptz-Adm1) ₃ ), and tris {2- [4- (2-adamantyl) -3-methyl-4H-1,2,4-triazol-5-yl-κN] phenyl-κC} iridium (III) (abbreviation: Ir (Mptz-Adm2) ₃ ). For comparison, calculation was also performed for tris (5-methyl-3,4-diphenyl-4H-1,2,4-triazolato) iridium (III) (abbreviation: Ir (Mptz) ₃ ). The structure and abbreviation of the iridium complex used for the calculation are shown below.

The method of quantum chemical calculation is as follows. First, the most stable structure in the singlet ground state (S ₀ ) and triplet excited state (T ₁ ) of the iridium complex was calculated using a density functional method (DFT). Note that Gaussian 09 was used as the quantum scientific calculation program. As the basis function, 6-311G (d, p) [H, C, N], Lan2dz [Ir] was used, and B3PW91 was used as the functional. The calculation was performed using a high performance computer (manufactured by SGI, Altix ICE8400EX). Note that the total energy of DFT is represented by the sum of potential energy, electrostatic energy between electrons, and exchange correlation energy including all the interactions between kinetic energy of electrons and complex electrons. In DFT, the exchange correlation interaction is approximated by a functional of one electron potential expressed by electron density (meaning a function of a function), and thus the calculation is highly accurate.

  Table 1 shows the triplet excitation energy levels estimated from the energy difference between the most stable structures in the singlet ground state and the triplet excited state. Also, the energy in the molecular orbitals of the highest occupied orbital (abbreviation: HOMO) and the lowest unoccupied molecular orbital (abbreviation: LUMO) calculated from the result of the most stable structure of the singlet ground state. Indicates the level.

As shown in Table 1, triplet excitation energy levels of Ir (Mptz-Adm1) ₃ and Ir (Mptz-Adm2) ₃ are similar to Ir (Mptz) ₃ and can exhibit blue light emission. .

2A, 2B, and 2C show spin density distributions in the most stable structure in the triplet excited state. Figure 2 Ir shown in _{(A) (Mptz-Adm1)} 3, and the spin density distribution in the Ir _{(Mptz-Adm2) 3} shown in FIG. 2 (B), mainly Ir metal, metal having a carbon atom which metalation It can be seen that the phenyl group and the metal are distributed in a five-membered ring having a nitrogen atom coordinated. On the other hand, the spin density distribution in Ir (Mptz) ₃ shown in FIG. 2C is in addition to a five-membered ring having an Ir metal, a phenyl group having a carbon atom to which the metal is metallized, and a nitrogen atom to which the metal is coordinated. In other words, it is also distributed to other phenyl groups bonded to the five-membered ring. That is, it is understood that the spin density distributions of Ir (Mptz-Adm1) ₃ and Ir (Mptz-Adm2) ₃ are smaller than Ir (Mptz) ₃ . Therefore, the half-value widths of the emission spectra of Ir (Mptz-Adm1) ₃ and Ir (Mptz-Adm2) _{3 in} the emission exhibited from the triplet excited state are larger than the half-value width of the emission spectrum of Ir (Mptz) _3. Expected to be small. That is, the guest material 122 having an adamantyl group illustrated in FIGS. 2A and 2B can exhibit blue light emission with favorable color purity.

From the calculation results of Table 1, Ir (Mptz-Adm1) ₃ and Ir (Mptz-Adm2) ₃ have a LUMO level larger than Ir (Mptz) ₃ . Therefore, when Ir (Mptz-Adm1) ₃ and Ir (Mptz-Adm2) ₃ are used as the guest material 122 of the light-emitting layer 110, it is preferable that the host material 121 used for the light-emitting layer 110 has a larger LUMO level. Specifically, the LUMO level of the host material 121 is preferably −3.0 eV or more. In addition, in order for electron carriers injected from the cathode to be transported by the electron transport layer 133 and smoothly injected into the light emitting layer, the LUMO level of the electron transport material of the electron transport layer 133 and the light emitting layer 110 The energy difference from the LUMO level of the host material 121 is preferably within 0.3 eV. In addition, by using a material having a large LUMO level for the host material 121 of the light-emitting layer 110, formation of an exciplex in the guest material 122 and the host material 121 can be suppressed.

  As described above, the light-emitting element 100 of one embodiment of the present invention includes the iridium complex that is a light-emitting substance as the guest material 122 of the light-emitting layer 110. The iridium complex includes a bridged cyclic hydrocarbon having an iridium metal, a ligand coordinated to the iridium metal, and a substituent bonded to the ligand, wherein the substituent has a mass number of 90 or more and less than 200. Since the ligand has a structure having a nitrogen-containing five-membered heterocyclic skeleton, blue light emission with good color purity can be exhibited.

  Next, the light-emitting element 100 illustrated in FIG. 1 will be described in more detail.

<Board>
The substrate 102 is used as a support for the light emitting element 100. As the substrate 102, for example, glass, quartz, plastic, or the like can be used. A flexible substrate may be used. The flexible substrate is a substrate that can be bent (flexible), and examples thereof include a plastic substrate made of polycarbonate, polyarylate, and polyethersulfone. A film (made of polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, etc.), an inorganic vapor deposition film, or the like can also be used.

  Note that a material other than the above may be used as long as it functions as a support in the manufacturing process of the light-emitting element 100. For example, the light-emitting element 100 can be formed using various substrates. The kind of board | substrate is not limited to a specific thing. As an example of the substrate, a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate, Examples include a substrate having a tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film. Examples of the glass substrate include barium borosilicate glass, aluminoborosilicate glass, and soda lime glass. Examples of the flexible substrate, the laminated film, and the base film include the following. For example, there are plastics represented by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Another example is a synthetic resin such as acrylic. Alternatively, examples include polypropylene, polyester, polyvinyl fluoride, and polyvinyl chloride. As an example, there are polyamide, polyimide, aramid, epoxy, an inorganic vapor deposition film, papers, and the like.

  Alternatively, a flexible substrate may be used as the substrate, and the light-emitting element 100 may be formed directly on the flexible substrate. Alternatively, a separation layer may be provided between the substrate and the light-emitting element 100. The release layer can be used to separate a part from the substrate after the light emitting element 100 is partially or wholly formed thereon and transfer it to another substrate. At that time, the light-emitting element 100 can be transferred to a substrate having poor heat resistance or a flexible substrate. Note that, for example, a structure of a laminated structure of an inorganic film of a tungsten film and a silicon oxide film or a structure in which an organic resin film such as polyimide is formed over a substrate can be used for the above-described release layer.

  That is, the light-emitting element 100 may be formed using a certain substrate, and then the light-emitting element 100 may be transferred to another substrate, and the light-emitting element 100 may be disposed on another substrate. Examples of a substrate to which the light emitting element 100 is transferred include a paper substrate, a cellophane substrate, an aramid film substrate, a polyimide film substrate, a stone substrate, a wood substrate, a cloth substrate (natural fibers (silk, cotton, hemp) ), Synthetic fibers (nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, and the like. By using these substrates, the light-emitting element 100 that is not easily broken, the light-emitting element 100 with high heat resistance, the light-emitting element 100 that is reduced in weight, or the light-emitting element 100 that is reduced in thickness can be obtained.

<A pair of electrodes>
For the lower electrode 104 and the upper electrode 114, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like can be used. Specifically, indium tin oxide (ITO), indium tin oxide containing silicon oxide or silicon oxide (ITSO: Indium Tin SiO ₂ Doped Oxide), indium oxide-zinc oxide, tungsten oxide, and Indium oxide containing zinc oxide, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper ( Cu), palladium (Pd), titanium (Ti), elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, alkali metals such as lithium (Li) and cesium (Cs), and calcium (Ca) , Alkaline earth metals such as strontium (Sr), and magnesium (Mg) , And alloys containing these (MgAg, AlLi), europium (Eu), ytterbium (Yb), and other rare earth metals, alloys containing these, and graphene. Note that the lower electrode 104 and the upper electrode 114 can be formed by, for example, a sputtering method or a vapor deposition method (including a vacuum vapor deposition method).

  In addition, one or both of the lower electrode 104 and the upper electrode 114 is light-transmitting so that light emitted from the EL layer 108 can be extracted to the outside.

<Light emitting layer>
The light-emitting layer 110 includes at least a host material 121 and a guest material 122. The guest material 122 functions as a light-emitting substance and has the iridium complex described above. The host material 121 includes one or both of an electron transporting material and a hole transporting material. Note that in the light-emitting element 100 illustrated in FIG. 1, the light-emitting layer 110 has a single-layer structure;

  Moreover, as an electron transport material used for the light emitting layer 110, a π-electron deficient heteroaromatic compound such as a nitrogen-containing heteroaromatic compound is preferable. As the electron transporting material, a π-electron deficient heteroaromatic, a metal complex, or the like can be used. Specifically, bis (10-hydroxybenzo [h] quinolinato) beryllium (II) (abbreviation: BeBq2), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (III) (abbreviation: BAlq), bis (8-quinolinolato) zinc (II) (abbreviation: Znq), bis [2- (2-benzoxazolyl) phenolato] zinc (II) (abbreviation: ZnPBO), bis [2- (2- Benzothiazolyl) phenolato] zinc (II) (abbreviation: ZnBTZ) or a metal complex such as 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 3- (4-biphenylyl) -4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole (abbreviation: TAZ), 1 3-bis [5- (p-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 9- [4- (5-phenyl-1, 3,4-oxadiazol-2-yl) phenyl] -9H-carbazole (abbreviation: CO11), 2,2 ′, 2 ″-(1,3,5-benzenetriyl) tris (1-phenyl- 1H-benzimidazole (abbreviation: TPBI), 2- [3- (dibenzothiophen-4-yl) phenyl] -1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II) and other heterocyclic rings having a polyazole skeleton Compounds, 2- [3- (dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTPDBq-II), 2- [3 ′-(dibenzothio) Nen-4-yl) biphenyl-3-yl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), 2- [3 ′-(9H-carbazol-9-yl) biphenyl-3-yl] dibenzo [F, h] quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis [3- (phenanthrene-9-yl) phenyl] pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis [3- (4-dibenzo A heterocyclic compound having a diazine skeleton such as thienyl) phenyl] pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 2- {4- [3- (N-phenyl-9H-carbazol-3-yl) -9H-carbazole -9-yl] phenyl} -4,6-diphenyl-1,3,5-triazine (PCCzPTzn) and other triazine skeletons Heterocyclic compounds, 3,5-bis [3- (9H-carbazol-9-yl) phenyl] pyridine (abbreviation: 3,5DCzPPy), 1,3,5-tri [3- (3-pyridyl) phenyl And heterocyclic compounds having a pyridine skeleton such as benzene (abbreviation: TmPyPB). Among the compounds described above, a heterocyclic compound having a pyridine skeleton or a pyrimidine skeleton is preferable because it has a high electron transport property and a high LUMO level.

  Further, as the hole transporting material used for the light emitting layer 110, a π-electron rich heteroaromatic compound or an aromatic amine compound is preferable. As the hole transporting material, a π electron excess type heteroaromatic or aromatic amine can be suitably used as the hole transporting material. Specifically, 2- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] spiro-9,9′-bifluorene (abbreviation: PCASF), 4,4′-bis [N- ( 1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), N, N′-bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4 ′ -Diamine (abbreviation: TPD), 4,4'-bis [N- (spiro-9,9'-bifluoren-2-yl) -N-phenylamino] biphenyl (abbreviation: BSPB), 4-phenyl-4 ' -(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP), 4-phenyl-3 '-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: mBPAFLP), 4-pheni -4 ′-(9-phenyl-9H-carbazol-3-yl) triphenylamine (abbreviation: PCBA1BP), 4,4′-diphenyl-4 ″-(9-phenyl-9H-carbazol-3-yl) Triphenylamine (abbreviation: PCBBi1BP), 4- (1-naphthyl) -4 ′-(9-phenyl-9H-carbazol-3-yl) triphenylamine (abbreviation: PCBBANB), 4,4′-di (1 -Naphthyl) -4 ''-(9-phenyl-9H-carbazol-3-yl) triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N- [4- (9-phenyl- 9H-carbazol-3-yl) phenyl] -fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N- [4- (9-phenyl-9H-carbazole) 3-yl) phenyl] -spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), N- (1,1'-biphenyl-4-yl) -N- [4- (9-phenyl- 9H-carbazol-3-yl) phenyl] -9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) and other compounds having an aromatic amine skeleton, 1,3-bis (N-carbazolyl) Benzene (abbreviation: mCP), 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), 3,6-bis (3,5-diphenylphenyl) -9-phenylcarbazole (abbreviation: CzTP), 9 -Compounds having a carbazole skeleton such as phenyl-9H-3- (9-phenyl-9H-carbazol-3-yl) carbazole (abbreviation: PCCP), and 4,4 ′, 4 ″ -(Benzene-1,3,5-triyl) tri (dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4- [4- (9-phenyl-9H-fluoren-9-yl) phenyl ] Having a thiophene skeleton such as dibenzothiophene (abbreviation: DBTFLP-III), 4- [4- (9-phenyl-9H-fluoren-9-yl) phenyl] -6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) Compounds, 4,4 ′, 4 ″-(benzene-1,3,5-triyl) tri (dibenzofuran) (abbreviation: DBF3P-II), 4- {3- [3- (9-phenyl-9H— And a compound having a furan skeleton such as fluoren-9-yl) phenyl] phenyl} dibenzofuran (abbreviation: mmDBFFLBi-II). Among the compounds described above, a compound having an aromatic amine skeleton and a compound having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reduction in driving voltage.

  As the hole-transporting material used for the light-emitting layer 110, poly (N-vinylcarbazole) (abbreviation: PVK), poly (4-vinyltriphenylamine) (abbreviation: PVTPA), poly [N- (4- { N ′-[4- (4-diphenylamino) phenyl] phenyl-N′-phenylamino} phenyl) methacrylamide] (abbreviation: PTPDMA) poly [N, N′-bis (4-butylphenyl) -N, N A high molecular compound such as “-bis (phenyl) benzidine” (abbreviation: Poly-TPD) can also be used.

  The above-described electron transporting material and hole transporting material used for the light-emitting layer 110 may be a combination that forms an exciplex (also referred to as an exciplex). For example, the electron transporting material used for the light-emitting layer 110 receives electrons, and the hole transporting material receives holes. At this time, an exciplex is rapidly formed by the proximity of the electron transporting material and the hole transporting material. Therefore, most excitons in the light emitting layer 110 exist as exciplexes. Since the exciplex has a smaller band gap than both the electron transporting material and the hole transporting material, the driving voltage of the light emitting element 100 can be lowered.

It is preferable that energy be transferred from the exciplex to the iridium complex of one embodiment of the present invention. Specifically, the energy of both the lowest level (S _E ) of the singlet excited state of the exciplex and the lowest level (T _E ) of the triplet excited state of the exciplex is expressed as the triple energy of the iridium complex. It is preferable to emit light by moving to the lowest level of the term excited state because high light emission efficiency can be obtained.

<Hole injection layer, hole transport layer>
The hole injection layer 131 is a layer that injects holes into the first light-emitting layer 110 and the second light-emitting layer 112 through the hole-transport layer 132 having a high hole-transport property. It is a layer containing an acceptor substance. By including the hole transporting material and the acceptor substance, electrons are extracted from the hole transporting material by the acceptor substance to generate holes, and the first light-emitting layer 110 and Holes are injected into the second light emitting layer 112. Note that the hole-transport layer 132 is formed using a hole-transport material.

  As the hole-transporting material used for the hole-injecting layer 131 and the hole-transporting layer 132, a material similar to the hole-transporting material that can be used for the light-emitting layer 110 described above may be used.

  As an acceptor substance used for the hole injecting layer 131, an oxide of a metal belonging to Groups 4 to 8 in the periodic table can be given. Specifically, molybdenum oxide is particularly preferable.

<Electron transport layer>
For the electron-transport layer 133, a material similar to the electron-transport material that can be used for the light-emitting layer 110 described above may be used. In particular, as the electron-transport layer 133, a heterocyclic compound having a pyridine skeleton or a pyrimidine skeleton is preferable because it has a high electron-transport property and a high LUMO level. Alternatively, when the electron transport layer 133 has a skeleton similar to that of the host material of the light emitting layer 110, electron carriers injected from the cathode are transported by the electron transport layer 133 and are smoothly injected into the light emitting layer 110. preferable. Alternatively, it is preferable that the energy difference between the LUMO level of the electron transport material included in the electron transport layer 133 and the LUMO level of the host material 121 of the light-emitting layer 110 be within 0.3 eV.

<Electron injection layer>
The electron injection layer 134 is a layer containing a substance having a high electron injection property. The electron injection layer 134 includes an alkali metal, an alkaline earth metal such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ ), lithium oxide (LiO _x ), or the like. These compounds can be used. Alternatively, a rare earth metal compound such as erbium fluoride (ErF ₃ ) can be used. Further, electride may be used for the electron injection layer 134. Examples of the electride include a substance obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum.

  Alternatively, a composite material obtained by mixing an organic compound and an electron donor (donor) may be used for the electron injection layer 134. Such a composite material is excellent in electron injecting property and electron transporting property because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, for example, a substance (metal complex, heteroaromatic compound, or the like) constituting the electron transport layer 133 described above is used. Can be used. The electron donor may be any substance that exhibits an electron donating property to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferable, and lithium, cesium, magnesium, calcium, erbium, ytterbium, and the like can be given. Alkali metal oxides and alkaline earth metal oxides are preferable, and lithium oxide, calcium oxide, barium oxide, and the like can be given. A Lewis base such as magnesium oxide can also be used. Alternatively, an organic compound such as tetrathiafulvalene (abbreviation: TTF) can be used.

  As described above, the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments or the structures described in the other examples.

(Embodiment 2)
In this embodiment, a light-emitting element which is one embodiment of the present invention will be described with reference to FIGS. Note that FIG. 3 is a schematic cross-sectional view illustrating the light-emitting element 150 of one embodiment of the present invention.

  The light-emitting element 150 includes a plurality of EL layers (the first EL layer 141 and the second EL layer 142 in FIG. 3) between the lower electrode 104 and the upper electrode 114. One or both of the first EL layer 141 and the second EL layer 142 have the same structure as the EL layer 108 illustrated in FIG. That is, the light-emitting element 100 illustrated in FIG. 1 includes one EL layer, and the light-emitting element 150 includes a plurality of EL layers. Note that in this embodiment, an EL layer is a layer including at least a light-emitting substance.

  In the light-emitting element 150 illustrated in FIGS. 3A and 3B, a first EL layer 141 and a second EL layer 142 are stacked, and a charge is interposed between the first EL layer 141 and the second EL layer 142. A generation layer 143 is provided. Note that the first EL layer 141 and the second EL layer 142 may have the same structure or different structures.

The charge generation layer 143 contains a composite material of an organic compound and a metal oxide. As the composite material, a composite material that can be used for the hole injection layer 131 described above may be used. As the organic compound, various compounds such as an aromatic amine compound, a carbazole compound, an aromatic hydrocarbon, and a high molecular compound (oligomer, dendrimer, polymer, etc.) can be used. Note that an organic compound having a hole mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher is preferably used. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used. Since the composite material of an organic compound and a metal oxide is excellent in carrier injecting property and carrier transporting property, low voltage driving and low current driving can be realized. Note that in the case where the anode-side surface of the EL layer 141 or the EL layer 142 is in contact with the charge generation layer 143, the charge generation layer 143 can also serve as a hole transport layer of the EL layer 141 or the EL layer 142. Therefore, the EL layer 141 or the EL layer 142 is not necessarily provided with a hole transport layer.

  Note that the charge generation layer 143 may be formed as a stacked structure in which a layer including a composite material of an organic compound and a metal oxide and a layer formed using another material are combined. For example, a layer including a composite material of an organic compound and a metal oxide may be combined with a layer including one compound selected from electron donating substances and a compound having a high electron transporting property. Alternatively, a layer including a composite material of an organic compound and a metal oxide may be combined with a transparent conductive film.

  Note that the charge generation layer 143 sandwiched between the first EL layer 141 and the second EL layer 142 injects electrons into one EL layer when a voltage is applied to the lower electrode 104 and the upper electrode 114, and the other Any material that injects holes into the EL layer may be used. For example, in FIG. 3, when a voltage is applied so that the potential of the lower electrode 104 is higher than the potential of the upper electrode 114, the charge generation layer 143 injects electrons into the first EL layer 141, Any material that injects holes into the second EL layer 142 may be used.

  3 illustrates a light-emitting element having two EL layers, the present invention can be similarly applied to a light-emitting element in which three or more EL layers are stacked. Like the light-emitting element 150, a plurality of EL layers are separated by a charge generation layer between a pair of electrodes, enabling high-intensity light emission while maintaining a low current density and realizing a longer-lifetime element it can. In addition, a light-emitting device that can be driven at a low voltage and has low power consumption can be realized.

  Note that when the EL layer 108 or the light-emitting layer 110 described in Embodiment 1 is included in at least one EL layer among the plurality of EL layers, a light-emitting element with high emission efficiency can be obtained.

Alternatively, a fluorescent material may be used as a light-emitting substance for either the first EL layer 141 or the second EL layer 142. As a host material when a fluorescent material is used for either the first EL layer 141 or the second EL layer 142, an anthracene derivative or a tetracene derivative is preferable. This is because these derivatives have a large S ₁ level and a small T ₁ level. Specifically, 9-phenyl-3- [4- (10-phenyl-9-anthryl) phenyl] -9H-carbazole (PCzPA), 3- [4- (1-naphthyl) -phenyl] -9-phenyl -9H-carbazole (PCPN), 9- [4- (10-phenyl-9-anthracenyl) phenyl] -9H-carbazole (CzPA), 7- [4- (10-phenyl-9-anthryl) phenyl] -7H -Dibenzo [c, g] carbazole (cgDBCzPA), 6- [3- (9,10-diphenyl-2-anthryl) phenyl] -benzo [b] naphtho [1,2-d] furan (2mBnfPPA), 9- Phenyl-10- {4- (9-phenyl-9H-fluoren-9-yl) -biphenyl-4'-yl} -anthracene (FLPPA) and the like. The Alternatively, 5,12-diphenyltetracene, 5,12-bis (biphenyl-2-yl) tetracene, and the like can be given.

  Examples of the fluorescent material include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, naphthalene derivatives, and the like. In particular, a pyrene derivative is preferable because of its high emission quantum yield. Specific examples of the pyrene derivative include N, N′-bis (3-methylphenyl) -N, N′-bis [3- (9-phenyl-9H-fluoren-9-yl) phenyl] pyrene-1,6. -Diamine (1,6 mM emFLPAPrn), N, N'-bis [4- (9-phenyl-9H-fluoren-9-yl) phenyl] -N, N'-diphenylpyrene-1,6-diamine (1,6FLPAPrn ), N, N′-bis (dibenzofuran-2-yl) -N, N′-diphenylpyrene-1,6-diamine (1,6FrAPrn), N, N′-bis (dibenzothiophen-2-yl)- N, N′-diphenylpyrene-1,6-diamine (1,6ThAPrn) and the like can be mentioned.

  Note that the above structure can be combined with any of the other embodiments and the other structures in this embodiment as appropriate.

(Embodiment 3)
In this embodiment, a display device including the light-emitting device of one embodiment of the present invention will be described with reference to FIGS.

  4A is a block diagram illustrating a display device of one embodiment of the present invention, and FIG. 4B illustrates a pixel circuit included in the display device of one embodiment of the present invention. It is a circuit diagram.

  A display device illustrated in FIG. 4A includes a circuit portion (hereinafter referred to as a pixel portion 802) including a pixel of a display element and a circuit which is disposed outside the pixel portion 802 and drives the pixel. , A driver circuit portion 804), a circuit having an element protection function (hereinafter referred to as a protection circuit 806), and a terminal portion 807. Note that the protection circuit 806 may not be provided.

  Part or all of the driver circuit portion 804 is preferably formed over the same substrate as the pixel portion 802. Thereby, the number of parts and the number of terminals can be reduced. When part or all of the driver circuit portion 804 is not formed over the same substrate as the pixel portion 802, part or all of the driver circuit portion 804 is formed by COG or TAB (Tape Automated Bonding). Can be implemented.

  The pixel portion 802 includes a circuit (hereinafter referred to as a pixel circuit 801) for driving a plurality of display elements arranged in X rows (X is a natural number of 2 or more) and Y columns (Y is a natural number of 2 or more). The driver circuit portion 804 outputs a signal (scanning signal) for selecting a pixel (hereinafter referred to as a gate driver 804a), and a circuit for supplying a signal (data signal) for driving a display element of the pixel (data signal). Hereinafter, a driver circuit such as a source driver 804b) is provided.

  The gate driver 804a includes a shift register and the like. The gate driver 804a receives a signal for driving the shift register via the terminal portion 807 and outputs a signal. For example, the gate driver 804a receives a start pulse signal, a clock signal, and the like and outputs a pulse signal. The gate driver 804a has a function of controlling the potential of a wiring to which a scan signal is supplied (hereinafter referred to as scan lines GL_1 to GL_X). Note that a plurality of gate drivers 804a may be provided, and the scanning lines GL_1 to GL_X may be divided and controlled by the plurality of gate drivers 804a. Alternatively, the gate driver 804a has a function of supplying an initialization signal. However, the present invention is not limited to this, and the gate driver 804a can supply another signal.

  The source driver 804b includes a shift register and the like. In addition to a signal for driving the shift register, the source driver 804b receives a signal (image signal) as a source of a data signal through the terminal portion 807. The source driver 804b has a function of generating a data signal to be written in the pixel circuit 801 based on the image signal. The source driver 804b has a function of controlling output of a data signal in accordance with a pulse signal obtained by inputting a start pulse, a clock signal, or the like. The source driver 804b has a function of controlling the potential of a wiring to which a data signal is supplied (hereinafter referred to as data lines DL_1 to DL_Y). Alternatively, the source driver 804b has a function of supplying an initialization signal. However, the present invention is not limited to this, and the source driver 804b can supply another signal.

  The source driver 804b is configured using, for example, a plurality of analog switches. The source driver 804b can output a signal obtained by time-dividing an image signal as a data signal by sequentially turning on a plurality of analog switches. Further, the source driver 804b may be configured using a shift register or the like.

  Each of the plurality of pixel circuits 801 receives a pulse signal through one of the plurality of scanning lines GL to which the scanning signal is applied, and receives the data signal through one of the plurality of data lines DL to which the data signal is applied. Entered. Also. In each of the plurality of pixel circuits 801, writing and holding of the data signal is controlled by the gate driver 804a. For example, the pixel circuit 801 in the m-th row and the n-th column receives a pulse signal from the gate driver 804a through the scanning line GL_m (m is a natural number equal to or less than X), and the data line DL_n (n Is a natural number less than or equal to Y), a data signal is input from the source driver 804b.

  The protection circuit 806 illustrated in FIG. 4A is connected to, for example, the scanning line GL that is a wiring between the gate driver 804a and the pixel circuit 801. Alternatively, the protection circuit 806 is connected to the data line DL that is a wiring between the source driver 804 b and the pixel circuit 801. Alternatively, the protection circuit 806 can be connected to a wiring between the gate driver 804 a and the terminal portion 807. Alternatively, the protection circuit 806 can be connected to a wiring between the source driver 804 b and the terminal portion 807. Note that the terminal portion 807 is a portion where a terminal for inputting a power supply, a control signal, and an image signal from an external circuit to the display device is provided.

  The protection circuit 806 is a circuit that brings a wiring into a conductive state when a potential outside a certain range is applied to the wiring to which the protection circuit 806 is connected.

  As shown in FIG. 4A, by providing a protection circuit 806 in each of the pixel portion 802 and the driver circuit portion 804, resistance of the display device to an overcurrent generated by ESD (Electro Static Discharge) or the like is increased. be able to. However, the configuration of the protection circuit 806 is not limited thereto, and for example, a configuration in which the protection circuit 806 is connected to the gate driver 804a or a configuration in which the protection circuit 806 is connected to the source driver 804b may be employed. Alternatively, the protective circuit 806 can be connected to the terminal portion 807.

  4A illustrates an example in which the driver circuit portion 804 is formed using the gate driver 804a and the source driver 804b; however, the present invention is not limited to this structure. For example, only the gate driver 804a may be formed and a substrate on which a separately prepared source driver circuit is formed (for example, a driver circuit substrate formed of a single crystal semiconductor film or a polycrystalline semiconductor film) may be mounted.

  In addition, the plurality of pixel circuits 801 illustrated in FIG. 4A can have a structure illustrated in FIG. 4B, for example.

  A pixel circuit 801 illustrated in FIG. 4B includes transistors 852 and 854, a capacitor 862, and a light-emitting element 872.

  One of a source electrode and a drain electrode of the transistor 852 is electrically connected to a wiring to which a data signal is supplied (hereinafter referred to as a signal line DL_n). Further, the gate electrode of the transistor 852 is electrically connected to a wiring to which a gate signal is supplied (hereinafter referred to as a scanning line GL_m).

  The transistor 852 has a function of controlling data writing of the data signal by being turned on or off.

  One of the pair of electrodes of the capacitor 862 is electrically connected to a wiring to which a potential is applied (hereinafter referred to as a potential supply line VL_a), and the other is electrically connected to the other of the source electrode and the drain electrode of the transistor 852. Is done.

  The capacitor 862 functions as a storage capacitor for storing written data.

  One of a source electrode and a drain electrode of the transistor 854 is electrically connected to the potential supply line VL_a. Further, the gate electrode of the transistor 854 is electrically connected to the other of the source electrode and the drain electrode of the transistor 852.

  One of an anode and a cathode of the light-emitting element 872 is electrically connected to the potential supply line VL_b, and the other is electrically connected to the other of the source electrode and the drain electrode of the transistor 854.

  As the light-emitting element 872, the light-emitting element 100 described in Embodiment 1 can be used.

  Note that one of the potential supply line VL_a and the potential supply line VL_b is supplied with the high power supply potential VDD, and the other is supplied with the low power supply potential VSS.

  In the display device including the pixel circuit 801 in FIG. 4B, for example, the pixel circuits 801 in each row are sequentially selected by the gate driver 804a illustrated in FIG. Write.

  The pixel circuit 801 in which data is written is brought into a holding state when the transistor 852 is turned off. Further, the amount of current flowing between the source electrode and the drain electrode of the transistor 854 is controlled in accordance with the potential of the written data signal, and the light-emitting element 872 emits light with luminance corresponding to the flowing current amount. By sequentially performing this for each row, an image can be displayed.

  Further, the pixel circuit may have a function of correcting the influence of fluctuations such as the threshold voltage of the transistor. FIGS. 5A and 5B and FIGS. 6A and 6B show examples of pixel circuits.

  The pixel circuit illustrated in FIG. 5A includes six transistors (transistors 303_1 to 303_6), a capacitor 304, and a light-emitting element 305. In addition, the wirings 301_1 to 301_5, the wirings 302_1, and 302_2 are electrically connected to the pixel circuit illustrated in FIG. Note that as the transistors 303_1 to 303_6, for example, p-type transistors can be used.

  The pixel circuit illustrated in FIG. 5B has a structure in which a transistor 303_7 is added to the pixel circuit illustrated in FIG. In addition, a wiring 301_6 and a wiring 301_7 are electrically connected to the pixel circuit illustrated in FIG. Here, the wiring 301_5 and the wiring 301_6 may be electrically connected to each other. Note that for the transistor 303_7, for example, a p-type transistor can be used.

  The pixel circuit illustrated in FIG. 6A includes six transistors (transistors 308_1 to 308_6), a capacitor 304, and a light-emitting element 305. In addition, wirings 306_1 to 306_3 and wirings 307_1 to 307_3 are electrically connected to the pixel circuit illustrated in FIG. Here, the wiring 306_1 and the wiring 306_3 may be electrically connected to each other. Note that as the transistors 308_1 to 308_6, for example, p-type transistors can be used.

  The pixel circuit illustrated in FIG. 6B includes two transistors (a transistor 309_1 and a transistor 309_2), two capacitors (a capacitor 304_1 and a capacitor 304_2), and a light-emitting element 305. In addition, wirings 311_1 to 311_3, a wiring 312_1, and a wiring 312_2 are electrically connected to the pixel circuit illustrated in FIG. In addition, with the structure of the pixel circuit illustrated in FIG. 6B, for example, a voltage input-current driving method (also referred to as a CVCC method) can be employed. Note that as the transistors 309_1 and 309_2, for example, a p-type transistor can be used.

  The light-emitting element of one embodiment of the present invention can be applied to an active matrix method in which an active element is included in a pixel of a display device or a passive matrix method in which an active element is not included in a pixel of a display device. .

  In the active matrix system, not only transistors but also various active elements (active elements and nonlinear elements) can be used as active elements (active elements and nonlinear elements). For example, MIM (Metal Insulator Metal) or TFD (Thin Film Diode) can be used. Since these elements have few manufacturing steps, manufacturing cost can be reduced or yield can be improved. Alternatively, since these elements have small element sizes, the aperture ratio can be improved, and power consumption and luminance can be increased.

  As a method other than the active matrix method, a passive matrix type that does not use an active element (an active element or a non-linear element) can be used. Since no active element (active element or non-linear element) is used, the number of manufacturing steps is small, so that manufacturing costs can be reduced or yield can be improved. Alternatively, since an active element (an active element or a non-linear element) is not used, an aperture ratio can be improved, power consumption can be reduced, or luminance can be increased.

  The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 4)
In this embodiment, a display panel including the light-emitting device of one embodiment of the present invention and an electronic device in which the input device is attached to the display panel will be described with reference to FIGS.

<Description 1 regarding touch panel>
Note that in this embodiment, a touch panel 2000 including a display panel and an input device is described as an example of an electronic device. A case where a touch sensor is used as an example of the input device will be described. Note that the light-emitting device of one embodiment of the present invention can be used for a pixel of a display panel.

  7A and 7B are perspective views of the touch panel 2000. FIG. 7A and 7B, typical components of the touch panel 2000 are shown for clarity.

  The touch panel 2000 includes a display panel 2501 and a touch sensor 2595 (see FIG. 7B). The touch panel 2000 includes a substrate 2510, a substrate 2570, and a substrate 2590. Note that the substrate 2510, the substrate 2570, and the substrate 2590 are all flexible. Note that any one or all of the substrate 2510, the substrate 2570, and the substrate 2590 may not have flexibility.

  The display panel 2501 includes a plurality of pixels and a plurality of wirings 2511 that can supply signals to the pixels over the substrate 2510. The plurality of wirings 2511 are routed to the outer periphery of the substrate 2510, and a part of them constitutes a terminal 2519. A terminal 2519 is electrically connected to the FPC 2509 (1).

  The substrate 2590 includes a touch sensor 2595 and a plurality of wirings 2598 electrically connected to the touch sensor 2595. The plurality of wirings 2598 are drawn around the outer periphery of the substrate 2590, and a part of them constitutes a terminal. The terminal is electrically connected to the FPC 2509 (2). Note that in FIG. 7B, electrodes, wirings, and the like of the touch sensor 2595 provided on the back side of the substrate 2590 (the side facing the substrate 2510) are indicated by solid lines for clarity.

  As the touch sensor 2595, for example, a capacitive touch sensor can be used. Examples of the electrostatic capacity method include a surface electrostatic capacity method and a projection electrostatic capacity method.

  As the projected capacitance method, there are mainly a self-capacitance method and a mutual capacitance method due to a difference in driving method. The mutual capacitance method is preferable because simultaneous multipoint detection is possible.

  Note that a touch sensor 2595 illustrated in FIG. 7B has a structure to which a projected capacitive touch sensor is applied.

  Note that as the touch sensor 2595, various sensors that can detect the proximity or contact of a detection target such as a finger can be used.

  The projected capacitive touch sensor 2595 includes an electrode 2591 and an electrode 2592. The electrode 2591 is electrically connected to any of the plurality of wirings 2598, and the electrode 2592 is electrically connected to any other of the plurality of wirings 2598.

  As shown in FIGS. 7A and 7B, the electrode 2592 has a shape in which a plurality of quadrilaterals repeatedly arranged in one direction are connected at corners.

  The electrode 2591 has a quadrangular shape and is repeatedly arranged in a direction intersecting with the direction in which the electrode 2592 extends.

  The wiring 2594 is electrically connected to two electrodes 2591 that sandwich the electrode 2592. At this time, a shape in which the area of the intersection of the electrode 2592 and the wiring 2594 is as small as possible is preferable. Thereby, the area of the area | region in which the electrode is not provided can be reduced, and the dispersion | variation in the transmittance | permeability can be reduced. As a result, variation in luminance of light transmitted through the touch sensor 2595 can be reduced.

  Note that the shapes of the electrode 2591 and the electrode 2592 are not limited thereto, and various shapes can be employed. For example, a plurality of electrodes 2591 may be arranged so as not to have a gap as much as possible, and a plurality of electrodes 2592 may be provided apart from each other so as to form a region that does not overlap with the electrodes 2591 with an insulating layer interposed therebetween. At this time, it is preferable to provide a dummy electrode electrically insulated from two adjacent electrodes 2592 because the area of regions having different transmittances can be reduced.

Note that a conductive film such as an electrode 2591, an electrode 2592, and a wiring 2598, that is, a transparent conductive film containing indium oxide, tin oxide, zinc oxide, or the like as a material that can be used for a wiring or an electrode constituting a touch panel (for example, ITO Etc.). In addition, as a material that can be used for the wiring and electrodes constituting the touch panel, for example, a lower resistance value is preferable. As an example, silver, copper, aluminum, carbon nanotube, graphene, metal halide (such as silver halide), or the like may be used. Furthermore, a metal nanowire configured using a plurality of conductors that are very thin (for example, a diameter of several nanometers) may be used. Or you may use the metal mesh which made the conductor a mesh shape. As an example, Ag nanowire, Cu nanowire, Al nanowire, Ag mesh, Cu mesh, Al mesh, or the like may be used. For example, when Ag nanowires are used for wirings and electrodes constituting the touch panel, the transmittance in visible light can be 89% or more, and the sheet resistance value can be 40Ω / cm ² or more and 100Ω / cm ² or less. In addition, metal nanowires, metal meshes, carbon nanotubes, graphene, and the like, which are examples of materials that can be used for the wiring and electrodes included in the touch panel described above, have high transmittance in visible light; For example, it may be used as a pixel electrode or a common electrode.

<Explanation about display panel>
Next, details of the display panel 2501 will be described with reference to FIG. FIG. 8A corresponds to a cross-sectional view taken along dashed-dotted line X1-X2 in FIG.

  The display panel 2501 includes a plurality of pixels arranged in a matrix. The pixel includes a display element and a pixel circuit that drives the display element.

As the substrate 2510 and the substrate 2570, for example, a flexible material having a water vapor permeability of 10 ⁻⁵ g / m ² · day or less, preferably 10 ⁻⁶ g / m ² · day or less is suitably used. be able to. Alternatively, a material in which the thermal expansion coefficient of the substrate 2510 and the thermal expansion coefficient of the substrate 2570 are approximately equal is preferably used. For example, a material having a linear expansion coefficient of 1 × 10 ⁻³ / K or less, preferably 5 × 10 ⁻⁵ / K or less, more preferably 1 × 10 ⁻⁵ / K or less can be suitably used.

  Note that the substrate 2510 is a stack including an insulating layer 2510a that prevents diffusion of impurities into the light-emitting element, a flexible substrate 2510b, and an adhesive layer 2510c that bonds the insulating layer 2510a and the flexible substrate 2510b. . The substrate 2570 is a stack including an insulating layer 2570a that prevents diffusion of impurities into the light-emitting element, a flexible substrate 2570b, and an adhesive layer 2570c that bonds the insulating layer 2570a and the flexible substrate 2570b. .

  As the adhesive layer 2510c and the adhesive layer 2570c, for example, a material containing polyester, polyolefin, polyamide (nylon, aramid, etc.), polyimide, polycarbonate, or a resin having an acrylic, urethane, epoxy, or siloxane bond can be used.

  In addition, a sealing layer 2560 is provided between the substrate 2510 and the substrate 2570. The sealing layer 2560 preferably has a refractive index larger than that of air. In addition, as illustrated in FIG. 8A, in the case where light is extracted to the sealing layer 2560 side, the sealing layer 2560 can also serve as an optical element.

  Further, a sealing material may be formed on the outer peripheral portion of the sealing layer 2560. By using the sealant, the light-emitting element 2550R can be provided in the region surrounded by the substrate 2510, the substrate 2570, the sealing layer 2560, and the sealant. Note that the sealing layer 2560 may be filled with an inert gas (such as nitrogen or argon). In addition, a drying material may be provided in the inert gas to adsorb moisture or the like. Moreover, as the above-mentioned sealing material, for example, it is preferable to use an epoxy resin or glass frit. As a material used for the sealant, a material that does not transmit moisture and oxygen is preferably used.

  In addition, the display panel 2501 includes a pixel 2502. In addition, the pixel 2502 includes a light emitting module 2580.

  The pixel 2502 includes a light-emitting element 2550R and a transistor 2502t that can supply power to the light-emitting element 2550R. Note that the transistor 2502t functions as part of the pixel circuit. In addition, the light-emitting module 2580 includes a light-emitting element 2550R and a colored layer 2567R.

  The light-emitting element 2550 includes a lower electrode, an upper electrode, and an EL layer between the lower electrode and the upper electrode. As the light-emitting element 2550, for example, the light-emitting element 100 described in Embodiment 1 can be used. Note that although only one light-emitting element 2550 is illustrated in the drawings, a structure including two or more light-emitting elements may be employed.

  In the case where the sealing layer 2560 is provided on the light extraction side, the sealing layer 2560 is in contact with the light-emitting element 2550 and the coloring layer 2567R.

  The coloring layer 2567R is in a position overlapping with the light-emitting element 2550. Thus, part of the light emitted from the light emitting element 2550 passes through the colored layer 2567R and is emitted to the outside of the light emitting module 2580 in the direction of the arrow shown in the drawing.

  In addition, the display panel 2501 is provided with a light-blocking layer 2567BM in a direction in which light is emitted. The light-blocking layer 2567BM is provided so as to surround the colored layer 2567R.

  The coloring layer 2567R may have a function of transmitting light in a specific wavelength band, for example, a color filter that transmits light in a red wavelength band, a color filter that transmits light in a green wavelength band, A color filter that transmits light in the blue wavelength band, a color filter that transmits light in the yellow wavelength band, and the like can be used. Each color filter can be formed using a variety of materials by a printing method, an inkjet method, an etching method using a photolithography technique, or the like.

  In addition, the display panel 2501 is provided with an insulating layer 2521. The insulating layer 2521 covers the transistor 2502t. Note that the insulating layer 2521 has a function of planarizing unevenness caused by the pixel circuit. Further, the insulating layer 2521 may have a function of suppressing impurity diffusion. Accordingly, a decrease in reliability of the transistor 2502t and the like due to impurity diffusion can be suppressed.

  The light-emitting element 2550R is formed above the insulating layer 2521. In addition, the lower electrode included in the light-emitting element 2550R is provided with a partition wall 2528 which overlaps with an end portion of the lower electrode. Note that a spacer for controlling the distance between the substrate 2510 and the substrate 2570 may be formed over the partition wall 2528.

  The scan line driver circuit 2503g includes a transistor 2503t and a capacitor 2503c. Note that the driver circuit can be formed over the same substrate in the same process as the pixel circuit.

  A wiring 2511 capable of supplying a signal is provided over the substrate 2510. A terminal 2519 is provided over the wiring 2511. In addition, the FPC 2509 (1) is electrically connected to the terminal 2519. The FPC 2509 (1) has a function of supplying a video signal, a clock signal, a start signal, a reset signal, and the like. Note that a printed wiring board (PWB) may be attached to the FPC 2509 (1).

  In addition, transistors with various structures can be used for the display panel 2501. FIG. 8A illustrates the case where a bottom-gate transistor is used; however, the invention is not limited to this. For example, a top-gate transistor illustrated in FIG. It is good also as a structure applied to.

  There are no particular limitations on the polarities of the transistors 2502t and 2503t, and a structure including N-type and P-type transistors or a structure including only one of an N-type transistor and a P-type transistor may be used. . Further, there is no particular limitation on the crystallinity of the semiconductor film used for the transistors 2502t and 2503t. For example, an amorphous semiconductor film or a crystalline semiconductor film can be used. Further, as a semiconductor material, a group III semiconductor (for example, a semiconductor having gallium), a group IV semiconductor (for example, a semiconductor having silicon), a compound semiconductor (including an oxide semiconductor), an organic semiconductor, or the like is used. it can. By using an oxide semiconductor with an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more for either or both of the transistor 2502t and the transistor 2503t, the off-state current of the transistor can be reduced. Therefore, it is preferable. Examples of the oxide semiconductor include In—Ga oxide and In—M—Zn oxide (M represents Al, Ga, Y, Zr, La, Ce, Sn, or Nd).

<Explanation about touch sensor>
Next, details of the touch sensor 2595 will be described with reference to FIG. FIG. 8C corresponds to a cross-sectional view taken along dashed-dotted line X3-X4 in FIG.

  The touch sensor 2595 includes electrodes 2591 and electrodes 2592 that are arranged in a staggered pattern on the substrate 2590, an insulating layer 2593 that covers the electrodes 2591 and 2592, and a wiring 2594 that electrically connects adjacent electrodes 2591.

  The electrodes 2591 and 2592 are formed using a light-transmitting conductive material. As the light-transmitting conductive material, a conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium is added can be used. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene oxide formed in a film shape. Examples of the reduction method include a method of applying heat.

  For example, after forming a light-transmitting conductive material over the substrate 2590 by a sputtering method, unnecessary portions are removed by various patterning techniques such as a photolithography method, so that the electrode 2591 and the electrode 2592 are formed. be able to.

  As a material used for the insulating layer 2593, for example, an inorganic insulating material such as silicon oxide, silicon oxynitride, or aluminum oxide can be used in addition to a resin such as acrylic or epoxy, or a resin having a siloxane bond.

  An opening reaching the electrode 2591 is provided in the insulating layer 2593 so that the wiring 2594 is electrically connected to the adjacent electrode 2591. Since the light-transmitting conductive material can increase the aperture ratio of the touch panel, it can be preferably used for the wiring 2594. A material having higher conductivity than the electrodes 2591 and 2592 can be preferably used for the wiring 2594 because electric resistance can be reduced.

  The electrode 2592 extends in one direction, and a plurality of electrodes 2592 are provided in a stripe shape. The wiring 2594 is provided so as to intersect with the electrode 2592.

  A pair of electrodes 2591 is provided with one electrode 2592 interposed therebetween. The wiring 2594 electrically connects the pair of electrodes 2591.

  Note that the plurality of electrodes 2591 are not necessarily arranged in a direction orthogonal to the one electrode 2592, and may be arranged to form an angle of more than 0 degree and less than 90 degrees.

  The wiring 2598 is electrically connected to the electrode 2591 or the electrode 2592. In addition, part of the wiring 2598 functions as a terminal. As the wiring 2598, for example, a metal material such as aluminum, gold, platinum, silver, nickel, titanium, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy material containing the metal material is used. it can.

  Note that an insulating layer that covers the insulating layer 2593 and the wiring 2594 may be provided to protect the touch sensor 2595.

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

  As the connection layer 2599, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

<Description 2 regarding touch panel>
Next, details of the touch panel 2000 will be described with reference to FIG. FIG. 9A corresponds to a cross-sectional view taken along dashed-dotted line X5-X6 in FIG.

  A touch panel 2000 illustrated in FIG. 9A has a structure in which the display panel 2501 described in FIG. 8A and the touch sensor 2595 described in FIG.

  In addition to the structure described in FIGS. 8A and 8C, the touch panel 2000 illustrated in FIG. 9A includes an adhesive layer 2597 and an antireflection layer 2567p.

  The adhesive layer 2597 is provided in contact with the wiring 2594. Note that the adhesive layer 2597 attaches the substrate 2590 to the substrate 2570 so that the touch sensor 2595 overlaps the display panel 2501. The adhesive layer 2597 preferably has a light-transmitting property. For the adhesive layer 2597, a thermosetting resin or an ultraviolet curable resin can be used. For example, an acrylic resin, a urethane resin, an epoxy resin, or a siloxane resin can be used.

  The antireflection layer 2567p is provided at a position overlapping the pixel. As the antireflection layer 2567p, for example, a circularly polarizing plate can be used.

  Next, a touch panel having a structure different from that illustrated in FIG. 9A will be described with reference to FIG.

  FIG. 9B is a cross-sectional view of the touch panel 2001. A touch panel 2001 illustrated in FIG. 9B is different from the touch panel 2000 illustrated in FIG. 9A in the position of the touch sensor 2595 with respect to the display panel 2501. Here, different configurations will be described in detail, and the description of the touch panel 2000 is used for a portion where a similar configuration can be used.

  The coloring layer 2567R is in a position overlapping with the light-emitting element 2550R. In addition, the light-emitting element 2550R illustrated in FIG. 9B emits light to the side where the transistor 2502t is provided. Thus, part of the light emitted from the light emitting element 2550R passes through the colored layer 2567R and is emitted to the outside of the light emitting module 2580 in the direction of the arrow shown in the drawing.

  Further, the touch sensor 2595 is provided on the substrate 2510 side of the display panel 2501.

  An adhesive layer 2597 is provided between the substrate 2510 and the substrate 2590, and the display panel 2501 and the touch sensor 2595 are attached to each other.

  As shown in FIGS. 9A and 9B, light emitted from the light emitting element may be emitted to one or both of the upper surface and the lower surface of the substrate.

<Explanation regarding touch panel drive method>
Next, an example of a touch panel driving method will be described with reference to FIG.

  FIG. 10A is a block diagram illustrating a structure of a mutual capacitive touch sensor. FIG. 10A shows a pulse voltage output circuit 2601 and a current detection circuit 2602. Note that in FIG. 10A, the electrode 2621 to which a pulse voltage is applied is illustrated as X1-X6, and the electrode 2622 for detecting a change in current is illustrated as Y1-Y6. FIG. 10A illustrates a capacitor 2603 formed by the overlap of the electrode 2621 and the electrode 2622. Note that the functions of the electrode 2621 and the electrode 2622 may be interchanged.

  The pulse voltage output circuit 2601 is a circuit for sequentially applying pulses to the wiring lines X1 to X6. When a pulse voltage is applied to the wiring of X1-X6, an electric field is generated between the electrode 2621 and the electrode 2622 forming the capacitor 2603. By utilizing the fact that the electric field generated between the electrodes causes a change in the mutual capacitance of the capacitor 2603 due to shielding or the like, it is possible to detect the proximity or contact of the detection object.

  The current detection circuit 2602 is a circuit for detecting a change in current in the wirings Y1 to Y6 due to a change in mutual capacitance in the capacitor 2603. In the wiring of Y1-Y6, there is no change in the current value detected when there is no proximity or contact with the detected object, but the current value when the mutual capacitance decreases due to the proximity or contact with the detected object. Detect changes that decrease. Note that current detection may be performed using an integration circuit or the like.

  Next, FIG. 10B shows a timing chart of input / output waveforms in the mutual capacitance type touch sensor shown in FIG. In FIG. 10B, the detection target is detected in each matrix in one frame period. FIG. 10B shows two cases, that is, a case where the detected object is not detected (non-touch) and a case where the detected object is detected (touch). In addition, about the wiring of Y1-Y6, the waveform made into the voltage value corresponding to the detected electric current value is shown.

  A pulse voltage is sequentially applied to the X1-X6 wiring, and the waveform of the Y1-Y6 wiring changes according to the pulse voltage. When there is no proximity or contact of the detection object, the waveform of Y1-Y6 changes uniformly according to the change of the voltage of the wiring of X1-X6. On the other hand, since the current value decreases at the location where the detection object is close or in contact, the waveform of the voltage value corresponding to this also changes.

  In this way, by detecting the change in mutual capacitance, the proximity or contact of the detection target can be detected.

<Explanation about sensor circuit>
FIG. 10A illustrates a passive touch sensor structure in which only a capacitor 2603 is provided at a wiring intersection as a touch sensor; however, an active touch sensor including a transistor and a capacitor may be used. An example of a sensor circuit included in the active touch sensor is shown in FIG.

  The sensor circuit illustrated in FIG. 11 includes a capacitor 2603, a transistor 2611, a transistor 2612, and a transistor 2613.

  The gate of the transistor 2613 is supplied with the signal G2, the voltage VRES is supplied to one of a source and a drain, and the other is electrically connected to one electrode of the capacitor 2603 and the gate of the transistor 2611. In the transistor 2611, one of a source and a drain is electrically connected to one of a source and a drain of the transistor 2612, and the voltage VSS is supplied to the other. In the transistor 2612, a signal G2 is supplied to a gate, and the other of the source and the drain is electrically connected to the wiring ML. The voltage VSS is applied to the other electrode of the capacitor 2603.

  Next, the operation of the sensor circuit shown in FIG. 11 will be described. First, a potential for turning on the transistor 2613 is supplied as the signal G2, so that a potential corresponding to the voltage VRES is applied to the node n to which the gate of the transistor 2611 is connected. Next, a potential for turning off the transistor 2613 is supplied as the signal G2, so that the potential of the node n is held.

  Subsequently, the potential of the node n changes from VRES as the mutual capacitance of the capacitor 2603 changes due to the proximity or contact of a detection object such as a finger.

  In the reading operation, a potential for turning on the transistor 2612 is supplied to the signal G1. The current flowing through the transistor 2611, that is, the current flowing through the wiring ML is changed in accordance with the potential of the node n. By detecting this current, the proximity or contact of the detection object can be detected.

  As the transistor 2611, the transistor 2612, and the transistor 2613, an oxide semiconductor layer is preferably used for a semiconductor layer in which a channel region is formed. In particular, when such a transistor is used as the transistor 2613, the potential of the node n can be held for a long time, and the frequency of the operation of supplying VRES to the node n (refresh operation) can be reduced. it can.

  The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 5)
In this embodiment, a display module and an electronic device each including the light-emitting device of one embodiment of the present invention will be described with reference to FIGS.

  A display module 8000 illustrated in FIG. 12 includes a touch sensor 8004 connected to the FPC 8003, a display panel 8006 connected to the FPC 8005, a frame 8009, a printed circuit board 8010, and a battery 8011 between an upper cover 8001 and a lower cover 8002. .

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

  The shapes and dimensions of the upper cover 8001 and the lower cover 8002 can be changed as appropriate in accordance with the sizes of the touch sensor 8004 and the display panel 8006.

  The touch sensor 8004 can be formed using a resistive touch panel or a capacitive touch panel superimposed on the display panel 8006. In addition, the counter substrate (sealing substrate) of the display panel 8006 can have a touch sensor function. In addition, an optical sensor may be provided in each pixel of the display panel 8006 to provide an optical touch sensor.

  The frame 8009 has a function as an electromagnetic shield for blocking electromagnetic waves generated by the operation of the printed board 8010 in addition to a protective function of the display panel 8006. The frame 8009 may have a function as a heat sink.

  The printed board 8010 includes a power supply circuit, a signal processing circuit for outputting a video signal and a clock signal. As a power supply for supplying power to the power supply circuit, an external commercial power supply may be used, or a power supply using a battery 8011 provided separately may be used. The battery 8011 can be omitted when a commercial power source is used.

  The display module 8000 may be additionally provided with a member such as a polarizing plate, a retardation plate, or a prism sheet.

  FIGS. 13A to 13H illustrate electronic devices. These electronic devices can include a housing 9000, a display portion 9001, a speaker 9003, operation keys 9005, a connection terminal 9006, a sensor 9007, a microphone 9008, and the like.

  The electronic devices illustrated in FIGS. 13A to 13G can have a variety of functions. For example, a function for displaying various information (still images, moving images, text images, etc.) on the display unit, a touch sensor function, a function for displaying a calendar, date or time, etc., a function for controlling processing by various software (programs) , Wireless communication function, function to connect to various computer networks using wireless communication function, function to transmit or receive various data using wireless communication function, read program or data recorded in recording medium A function of displaying on the display portion can be provided. Note that the functions of the electronic devices illustrated in FIGS. 13A to 13G are not limited to these, and can have various functions. Although not illustrated in FIGS. 13A to 13H, the electronic device may have a plurality of display portions. In addition, the electronic device is equipped with a camera, etc., to capture still images, to capture moving images, to store captured images on a recording medium (externally or built into the camera), and to display captured images on the display unit And the like.

  Details of the electronic devices illustrated in FIGS. 13A to 13G are described below.

  FIG. 13A is a perspective view showing a portable information terminal 9100. A display portion 9001 included in the portable information terminal 9100 has flexibility. Therefore, the display portion 9001 can be incorporated along the curved surface of the curved housing 9000. Further, the display portion 9001 includes a touch sensor and can be operated by touching the screen with a finger, a stylus, or the like. For example, an application can be activated by touching an icon displayed on the display unit 9001.

  FIG. 13B is a perspective view showing the portable information terminal 9101. The portable information terminal 9101 has one or a plurality of functions selected from, for example, a telephone, a notebook, an information browsing device, or the like. Specifically, it can be used as a smartphone. Note that the portable information terminal 9101 is illustrated with the speaker 9003, the connection terminal 9006, the sensor 9007, and the like omitted, but can be provided at the same position as the portable information terminal 9100 illustrated in FIG. Further, the portable information terminal 9101 can display characters and image information on the plurality of surfaces. For example, three operation buttons 9050 (also referred to as operation icons or simply icons) can be displayed on one surface of the display portion 9001. Further, information 9051 indicated by a broken-line rectangle can be displayed on another surface of the display portion 9001. As an example of the information 9051, a display for notifying an incoming call such as an e-mail, SNS (social networking service), a telephone call, a title such as an e-mail or SNS, a sender name such as an e-mail or SNS, a date and time, and a time , Battery level, antenna reception strength and so on. Alternatively, an operation button 9050 or the like may be displayed instead of the information 9051 at a position where the information 9051 is displayed.

  FIG. 13C is a perspective view showing the portable information terminal 9102. The portable information terminal 9102 has a function of displaying information on three or more surfaces of the display portion 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different planes. For example, the user of the portable information terminal 9102 can check the display (information 9053 here) in a state where the portable information terminal 9102 is stored in the chest pocket of clothes. Specifically, the telephone number or name of the caller of the incoming call is displayed at a position where it can be observed from above portable information terminal 9102. The user can check the display and determine whether to receive a call without taking out the portable information terminal 9102 from the pocket.

  FIG. 13D is a perspective view showing a wristwatch-type portable information terminal 9200. The portable information terminal 9200 can execute various applications such as a mobile phone, electronic mail, text browsing and creation, music playback, Internet communication, and computer games. Further, the display portion 9001 is provided with a curved display surface, and can perform display along the curved display surface. In addition, the portable information terminal 9200 can execute short-range wireless communication with a communication standard. For example, it is possible to talk hands-free by communicating with a headset capable of wireless communication. In addition, the portable information terminal 9200 includes a connection terminal 9006 and can directly exchange data with other information terminals via a connector. Charging can also be performed through the connection terminal 9006. Note that the charging operation may be performed by wireless power feeding without using the connection terminal 9006.

  13E, 13F, and 13G are perspective views illustrating a foldable portable information terminal 9201. FIG. 13E is a perspective view of a state in which the portable information terminal 9201 is expanded, and FIG. 13F is a state in the middle of changing from one of the expanded state or the folded state of the portable information terminal 9201 to the other. FIG. 13G is a perspective view of the portable information terminal 9201 folded. The portable information terminal 9201 is excellent in portability in the folded state, and in the expanded state, the portable information terminal 9201 is excellent in display listability due to a seamless wide display area. A display portion 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. By bending between the two housings 9000 via the hinge 9055, the portable information terminal 9201 can be reversibly deformed from the expanded state to the folded state. For example, the portable information terminal 9201 can be bent with a curvature radius of 1 mm to 150 mm.

  The electronic device described in this embodiment includes a display portion for displaying some information. Note that the light-emitting device of one embodiment of the present invention can also be applied to an electronic device having no display portion. In addition, in the display portion of the electronic device described in this embodiment, an example of a configuration that has flexibility and can display along a curved display surface, or a configuration of a foldable display portion is given. However, the present invention is not limited to this, and may have a configuration in which display is performed on a flat portion without having flexibility.

  The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 6)
In this embodiment, a light-emitting device of one embodiment of the present invention will be described with reference to FIGS.

  FIG. 14A shows a perspective view of the light-emitting device 3000 shown in this embodiment mode, and FIG. 14B shows a cross-sectional view corresponding to the area between dashed-dotted lines EF shown in FIG. Note that in FIG. 14A, some components are displayed with broken lines in order to avoid complexity of the drawing.

  A light-emitting device 3000 illustrated in FIGS. 14A and 14B includes a substrate 3001, a light-emitting element 3005 over the substrate 3001, a first sealing region 3007 provided on the outer periphery of the light-emitting element 3005, and a first seal. And a second sealing region 3009 provided on the outer periphery of the stop region 3007.

  Light emission from the light-emitting element 3005 is emitted from one or both of the substrate 3001 and the substrate 3003. 14A and 14B, a structure in which light emitted from the light-emitting element 3005 is emitted downward (substrate 3001 side) will be described.

  14A and 14B, the light-emitting device 3000 includes a light-emitting element 3005 that is surrounded by a first sealing region 3007 and a second sealing region 3007. It is a heavy sealing structure. With the double sealing structure, external impurities (for example, water, oxygen, and the like) that enter the light-emitting element 3005 side can be preferably suppressed. Note that the first sealing region 3007 and the second sealing region 3009 are not necessarily provided. For example, only the first sealing region 3007 may be configured.

  Note that in FIG. 14B, the first sealing region 3007 and the second sealing region 3009 are provided in contact with the substrate 3001 and the substrate 3003. However, the invention is not limited to this. For example, one or both of the first sealing region 3007 and the second sealing region 3009 are provided in contact with an insulating film or a conductive film formed over the substrate 3001. It is good also as a structure. Alternatively, one or both of the first sealing region 3007 and the second sealing region 3009 may be provided in contact with an insulating film or a conductive film formed below the substrate 3003.

  The substrate 3001 and the substrate 3003 may have structures similar to those of the substrate 102 and the substrate 152 described in Embodiment 1, respectively. The light-emitting element 3005 may have a structure similar to that of any one of the first to third light-emitting elements described in the above embodiment.

  As the first sealing region 3007, a material containing glass (eg, a glass frit, a glass ribbon, or the like) may be used. For the second sealing region 3009, a material containing a resin may be used. By using a material containing glass for the first sealing region 3007, productivity and sealing performance can be improved. In addition, by using a material containing a resin as the second sealing region 3009, impact resistance and heat resistance can be improved. Note that the first sealing region 3007 and the second sealing region 3009 are not limited to this, and the first sealing region 3007 is formed of a material containing a resin. May be formed of a material including glass.

  Examples of the glass frit include magnesium oxide, calcium oxide, strontium oxide, barium oxide, cesium oxide, sodium oxide, potassium oxide, boron oxide, vanadium oxide, zinc oxide, tellurium oxide, aluminum oxide, silicon dioxide, Lead oxide, tin oxide, phosphorus oxide, ruthenium oxide, rhodium oxide, iron oxide, copper oxide, manganese dioxide, molybdenum oxide, niobium oxide, titanium oxide, tungsten oxide, bismuth oxide, zirconium oxide, lithium oxide, antimony oxide, boric acid Including lead glass, tin phosphate glass, vanadate glass or borosilicate glass. In order to absorb infrared light, it is preferable to include at least one kind of transition metal.

  As the above-mentioned glass frit, for example, a frit paste is applied on a substrate, and heat treatment or laser irradiation is performed on the frit paste. The frit paste includes the glass frit and a resin diluted with an organic solvent (also called a binder). Alternatively, a glass frit to which an absorbent that absorbs light having a wavelength of laser light is added may be used. As the laser, for example, an Nd: YAG laser or a semiconductor laser is preferably used. Further, the laser irradiation shape during laser irradiation may be circular or quadrangular.

  Moreover, as a material containing the above-mentioned resin, the material containing resin which has polyester, polyolefin, polyamide (nylon, aramid etc.), a polyimide, a polycarbonate, an acryl, urethane, an epoxy, or a siloxane bond can be used, for example.

  Note that in the case where a material containing glass is used for one or both of the first sealing region 3007 and the second sealing region 3009, the coefficient of thermal expansion between the material containing glass and the substrate 3001 is close. preferable. By setting it as the said structure, it can suppress that a crack enters into the material or board | substrate 3001 containing glass with a thermal stress.

  For example, when a material containing glass is used for the first sealing region 3007 and a material containing resin is used for the second sealing region 3009, the following excellent effects are obtained.

  The second sealing region 3009 is provided closer to the outer peripheral portion of the light emitting device 3000 than the first sealing region 3007. As the light emitting device 3000 moves toward the outer periphery, distortion due to external force or the like increases. Therefore, the first sealing provided on the outer peripheral side of the light-emitting device 3000 where the distortion increases, that is, the second sealing region 3009, is sealed with a material containing resin and is provided on the inner side of the second sealing region 3009. By sealing the stop region 3007 with a material containing glass, the light-emitting device 3000 is hardly broken even when distortion such as external force occurs.

  As shown in FIG. 14B, a first region 3011 is formed in a region surrounded by the substrate 3001, the substrate 3003, the first sealing region 3007, and the second sealing region 3009. The A second region 3013 is formed in a region surrounded by the substrate 3001, the substrate 3003, the light-emitting element 3005, and the first sealing region 3007.

  The first region 3011 and the second region 3013 are preferably filled with an inert gas such as a rare gas or nitrogen gas, for example. Note that the first region 3011 and the second region 3013 are preferably in a reduced pressure state rather than an atmospheric pressure state.

  A modification of the configuration illustrated in FIG. 14B is illustrated in FIG. FIG. 14C is a cross-sectional view illustrating a modified example of the light-emitting device 3000.

  FIG. 14C illustrates a structure in which a recess is provided in part of the substrate 3003 and a desiccant 3018 is provided in the recess. The other structure is the same as the structure shown in FIG.

  As the desiccant 3018, a substance that adsorbs moisture or the like by chemical adsorption, or a substance that adsorbs moisture or the like by physical adsorption can be used. For example, substances that can be used as the desiccant 3018 include alkali metal oxides, alkaline earth metal oxides (such as calcium oxide and barium oxide), sulfates, metal halides, perchlorates, zeolites, Examples include silica gel.

  Next, modified examples of the light-emitting device 3000 illustrated in FIG. 14B will be described with reference to FIGS. 15A, 15B, 15C, and 15D. 15A, 15B, 15C, and 15D are cross-sectional views illustrating a modification of the light-emitting device 3000 illustrated in FIG.

  The light-emitting device illustrated in FIG. 15A has a structure in which the first sealing region 3007 is provided without providing the second sealing region 3009. In addition, the light-emitting device illustrated in FIG. 15A includes a region 3014 instead of the second region 3013 illustrated in FIG.

  As the region 3014, for example, a material containing polyester, polyolefin, polyamide (nylon, aramid, or the like), polyimide, polycarbonate, or a resin having an acrylic, urethane, epoxy, or siloxane bond can be used.

  When the above-described material is used for the region 3014, a so-called solid-sealed light-emitting device can be obtained.

  The light-emitting device illustrated in FIG. 15B has a structure in which a substrate 3015 is provided on the substrate 3001 side of the light-emitting device illustrated in FIG.

  The substrate 3015 has unevenness as illustrated in FIG. By providing the uneven substrate 3015 on the light extraction side of the light-emitting element 3005, the light extraction efficiency from the light-emitting element 3005 can be improved. Note that a substrate that functions as a diffusion plate may be provided instead of the structure having unevenness as illustrated in FIG.

  A light-emitting device illustrated in FIG. 15C has a structure in which light is extracted from the substrate 3003 side, whereas the light-emitting device illustrated in FIG. 15A extracts light from the substrate 3001 side.

  A light-emitting device illustrated in FIG. 15C includes a substrate 3015 on the substrate 3003 side. Other structures are similar to those of the light-emitting device illustrated in FIG.

  The light-emitting device illustrated in FIG. 15D has a structure in which the substrate 3016 is provided without providing the substrates 3003 and 3015 of the light-emitting device shown in FIG.

  The substrate 3016 has a first unevenness located on the side closer to the light emitting element 3005 and a second unevenness located on the side farther from the light emitting element 3005. With the structure illustrated in FIG. 15D, the light extraction efficiency from the light-emitting element 3005 can be further improved.

  Therefore, by implementing the structure described in this embodiment, a light-emitting device in which deterioration of the light-emitting element due to impurities such as moisture and oxygen is suppressed can be realized. Alternatively, by performing the structure described in this embodiment, a light-emitting device with high light extraction efficiency can be realized.

  Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments or examples.

(Embodiment 7)
In this embodiment, an example in which the light-emitting device of one embodiment of the present invention is applied to various lighting devices and electronic devices will be described with reference to FIGS.

  By manufacturing the light-emitting device of one embodiment of the present invention over a flexible substrate, an electronic device or a lighting device having a light-emitting region having a curved surface can be realized.

  In addition, the light-emitting device to which one embodiment of the present invention is applied can also be used for lighting of a car. For example, lighting can be provided on a dashboard, a windshield, a ceiling, or the like.

  16A shows a perspective view of one surface of the multifunction terminal 3500, and FIG. 16B shows a perspective view of the other surface of the multifunction terminal 3500. In the multi-function terminal 3500, a display portion 3504, a camera 3506, an illumination 3508, and the like are incorporated in a housing 3502. The light-emitting device of one embodiment of the present invention can be used for the lighting 3508.

  The illumination 3508 functions as a surface light source by using the light-emitting device of one embodiment of the present invention. Therefore, unlike a point light source typified by an LED, light emission with less directivity can be obtained. For example, when the lighting 3508 and the camera 3506 are used in combination, the lighting 3508 can be turned on or blinked and an image can be captured by the camera 3506. Since the illumination 3508 has a function as a surface light source, it can capture a photograph taken under natural light.

  Note that the multi-function terminal 3500 illustrated in FIGS. 16A and 16B can have various functions in a manner similar to the electronic devices illustrated in FIGS. 13A to 13G.

  In addition, a speaker, a sensor (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current are included in the housing 3502. , Voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared measurement function), microphone, and the like. Further, by providing a detection device having a sensor for detecting the inclination of a gyroscope, an acceleration sensor, or the like inside the multi-function terminal 3500, the orientation (vertical or horizontal) of the multi-function terminal 3500 is determined, and the display unit 3504 The screen display can be automatically switched.

  The display portion 3504 can also function as an image sensor. For example, personal authentication can be performed by touching the display portion 3504 with a palm or a finger and capturing a palm print, a fingerprint, or the like. In addition, when a backlight that emits near-infrared light or a sensing light source that emits near-infrared light is used for the display portion 3504, finger veins, palm veins, and the like can be imaged. Note that the light-emitting device of one embodiment of the present invention may be applied to the display portion 3054.

  FIG. 16C is a perspective view of a crime prevention light 3600. The light 3600 includes an illumination 3608 outside the housing 3602, and the housing 3602 incorporates a speaker 3610 and the like. The light-emitting device of one embodiment of the present invention can be used for the lighting 3608.

  As the light 3600, for example, light can be emitted by gripping, holding, or holding the illumination 3608. Further, an electronic circuit that can control a light emission method from the light 3600 may be provided inside the housing 3602. The electronic circuit may be, for example, a circuit that can emit light once or intermittently a plurality of times, or a circuit that can adjust the amount of light emitted by controlling the current value of light emission. Good. In addition, a circuit that outputs a loud alarm sound from the speaker 3610 at the same time as the light emission of the illumination 3608 may be incorporated.

  Since the light 3600 can emit light in all directions, for example, it can be threatened with light or light and sound toward a thief or the like. The light 3600 may be provided with a camera such as a digital still camera and a function having a photographing function.

  As described above, a lighting device and an electronic device can be obtained by using the light-emitting device of one embodiment of the present invention. Note that applicable lighting devices and electronic devices are not limited to those described in this embodiment and can be applied to electronic devices in various fields.

  Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

  In this example, an example of manufacturing a light-emitting element which is one embodiment of the present invention will be described. Note that in this example, a light-emitting element (light-emitting element 1) which is one embodiment of the present invention and a comparative light-emitting element (comparative light-emitting element 2) were manufactured.

  FIG. 17 is a schematic cross-sectional view of the light-emitting element 1 and the light-emitting element 2, FIG. 17 shows the details of the light-emitting element 1 and the light-emitting element 2, and the structures and abbreviations of the compounds used are shown below.

<1-1. Manufacturing Method of Light-Emitting Element 1>
First, indium tin oxide containing silicon oxide (abbreviation: ITSO) was formed as a lower electrode 504 over the substrate 502 by a sputtering method. The film thickness of the lower electrode 504 was 70 nm, and the area of the lower electrode 504 was 4 mm ² (2 mm × 2 mm).

  Next, as a pretreatment before vapor deposition of the organic compound layer, the lower electrode 504 side of the substrate 502 on which the lower electrode 504 is formed is washed with water and baked at 200 ° C. for 1 hour. UV ozone treatment was performed for 370 seconds.

Thereafter, the substrate 502 is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, and vacuum baking is performed at 170 ° C. for 60 minutes in a heating chamber in the vacuum vapor deposition apparatus. Allowed to cool.

  Next, the substrate 502 was fixed to a holder provided in the vacuum evaporation apparatus so that the surface on which the lower electrode 504 was formed faced downward. In this example, a hole injection layer 531, a hole transport layer 532, a light emitting layer 510, an electron transport layer 533, an electron injection layer 534, and an upper electrode 514 were sequentially formed by vacuum deposition. A detailed manufacturing method is described below.

First, after reducing the pressure in the vacuum apparatus to 10 ⁻⁴ Pa, 1,3,5-tri (dibenzothiophen-4-yl) benzene (DBT3P-II) is formed on the lower electrode 504 as the hole injection layer 531. Molybdenum oxide was co-deposited so that DBT3P-II: molybdenum oxide = 2: 1 (weight ratio). Note that the thickness of the hole injection layer 531 was set to 25 nm.

  Next, a hole transport layer 532 was formed over the hole injection layer 531. As the hole-transporting layer 532, 4,4′-bis (9-carbazole) -2,2′-dimethyl-biphenyl (abbreviation: dmCBP) was deposited. Note that the thickness of the hole transport layer 532 was set to 20 nm.

Next, the light-emitting layer 510 was formed over the hole transport layer 532. As the light-emitting layer 510, 3,5-bis [3- (9H-carbazol-9-yl) phenyl] pyridine (abbreviation: 3,5DCzPPy) and tris {2- [4- (2-adamantyl) -3-methyl -4H-1,2,4-triazol-5-yl- [kappa] N] phenyl- [kappa] C} iridium (III) (abbreviation: Ir (Mptz-Adm2) ₃ ) and 3,5DCzPPy: Ir (Mptz-Adm2) ₃ = 1: 0.06 (weight ratio) was co-evaporated. Note that the thickness of the light emitting layer 510 was set to 30 nm.

Note that in the light-emitting layer 510, 3,5DCzPPy is a host material and Ir (Mptz-Adm2) ₃ is a guest material.

  Next, 25 nm-thick 1,3,5-tri [3- (3-pyridyl) phenyl] benzene (abbreviation: TmPyPB) was deposited as an electron-transporting layer 533 over the light-emitting layer 510. Note that a material having a pyridine skeleton with a high electron-transport property was used for both the host material of the light-emitting layer 510 and the electron-transport layer 533 of the light-emitting element 1 which is one embodiment of the present invention.

  Next, lithium fluoride (LiF) having a thickness of 1 nm was deposited as an electron injection layer 534 on the electron transport layer 533.

  Next, 200 nm-thick aluminum (Al) was deposited as the upper electrode 514 on the electron injection layer 534.

  Next, a sealing substrate 552 was prepared.

Sealing was performed by bonding the light-emitting element 1 over the substrate 502 manufactured as described above and the sealing substrate 552 in a glove box in a nitrogen atmosphere so as not to be exposed to the air. As a sealing method, a sealing material was applied to the periphery of the element, and the sealing material was irradiated with ultraviolet light of 365 nm at 6 J / cm ² and then heat-treated at 80 ° C. for 1 hour.

  Through the above steps, the light-emitting element 1 was manufactured.

<1-2. Manufacturing Method of Comparative Light-Emitting Element 2>
First, ITSO was formed as a lower electrode 504 on the substrate 502 by a sputtering method. The film thickness of the lower electrode 504 was 70 nm, and the area of the lower electrode 504 was 4 mm ² (2 mm × 2 mm).

  Next, as a pretreatment before vapor deposition of the organic compound layer, the lower electrode 504 side of the substrate 502 on which the lower electrode 504 is formed is washed with water and baked at 200 ° C. for 1 hour. UV ozone treatment was performed for 370 seconds.

Thereafter, the substrate 502 is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, and vacuum baking is performed at 170 ° C. for 60 minutes in a heating chamber in the vacuum vapor deposition apparatus. Allowed to cool.

  Next, the substrate 502 was fixed to a holder provided in the vacuum evaporation apparatus so that the surface on which the lower electrode 504 was formed faced downward. In this example, a hole injection layer 531, a hole transport layer 532, a light emitting layer 510, an electron transport layer 533, an electron injection layer 534, and an upper electrode 514 were sequentially formed by vacuum deposition. A detailed manufacturing method is described below.

First, after reducing the pressure in the vacuum apparatus to 10 ⁻⁴ Pa, 9-phenyl-3- [4- (10-phenyl-9-anthryl) phenyl] -9H is formed on the lower electrode 504 as the hole injection layer 531. -Carbazole (abbreviation: PCzPA) and molybdenum oxide were co-deposited so that PCzPA: molybdenum oxide = 2: 1 (weight ratio). Note that the thickness of the hole injection layer 531 was set to 10 nm.

  Next, a hole transport layer 532 was formed over the hole injection layer 531. As the hole transport layer 532, PCzPA was deposited. Note that the thickness of the hole transport layer 532 was set to 10 nm.

  Next, the light-emitting layer 510 was formed over the hole transport layer 532. As the light-emitting layer 510, 7- [4- (10-phenyl-9-anthryl) phenyl] -7H-dibenzo [c, g] carbazole (abbreviation: cgDBCzPA) and N, N′-bis (3-methylphenyl) -N, N'-bis [3- (9-phenyl-9H-fluoren-9-yl) phenyl] pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn) and cgDBCzPA: 1,6mMemFLPAPrn = 1 Co-evaporation was carried out to 0.03 (weight ratio). Note that the thickness of the light emitting layer 510 was set to 25 nm.

  Note that in the light-emitting layer 510, cgDBCzPA is a host material and 1,6 mM emFLPAPrn is a guest material.

  Next, a 10-nm-thick cgDBCzPA and a 15-nm-thick bathophenanthroline (abbreviation: Bphen) were deposited as an electron-transporting layer 533 over the light-emitting layer 510. Next, 1 nm-thick LiF was deposited as an electron injection layer 534 on the electron transport layer 533.

  Next, Al having a thickness of 200 nm was deposited on the electron injection layer 534 as the upper electrode 514.

  Next, a sealing substrate 552 was prepared.

  Sealing was performed by bonding the comparative light emitting element 2 on the substrate 502 manufactured as described above and the sealing substrate 552 in a glove box in a nitrogen atmosphere so as not to be exposed to the air. The sealing method was the same as that of the light emitting element 1.

  The comparative light-emitting element 2 was manufactured through the above steps.

  In the vapor deposition process of the light emitting element 1 and the comparative light emitting element 2 described above, a resistance heating method was used as the vapor deposition method.

<1-3. Initial Characteristics of Light-Emitting Element 1 and Comparative Light-Emitting Element 2>
The luminance-current density characteristics of the light-emitting element 1 and the comparative light-emitting element 2 are illustrated in FIG. In addition, FIG. 18B illustrates luminance-voltage characteristics of the light-emitting element 1 and the comparative light-emitting element 2. In addition, FIG. 19A illustrates external quantum efficiency-luminance characteristics of the light-emitting element 1 and the comparative light-emitting element 2. Note that the measurement environment of each light-emitting element was room temperature (atmosphere kept at 25 ° C.). Table 3 shows element characteristics of the light-emitting element 1 and the comparative light-emitting element ² around 1000 cd / m ² .

FIG. 19B shows emission spectra obtained when current is supplied to the light-emitting element 1 and the comparative light-emitting element 2 at a current density of ^2.5 mA / cm ² .

  As shown in FIGS. 18 and 19 and Table 3, when the light-emitting element 1 which is one embodiment of the present invention and the comparative light-emitting element 2 for comparison are compared, the light-emitting element 1 has excellent initial characteristics. confirmed. In particular, regarding the external quantum efficiency, the external quantum efficiency was about four times that of the comparative light emitting device 2. Further, as shown in FIG. 19B, it is confirmed that the light emitting element 1 has an emission spectrum shifted to the short wavelength side by about 10 nm from the comparative light emitting element 2 and has an emission spectrum peak in a blue wavelength band. It was.

  As described above, the structure described in this example can be combined with any of the other examples and embodiments as appropriate.

100 light emitting element 102 substrate 104 lower electrode 108 EL layer 110 light emitting layer 112 light emitting layer 114 upper electrode 121 host material 122 guest material 131 hole injection layer 132 hole transport layer 133 electron transport layer 134 electron injection layer 141 EL layer 142 EL layer 143 Charge generation layer 150 Light-emitting element 152 Substrate 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 Capacitance element 304_1 Capacitance element 304_2 Capacitance element 305 Light emitting element 306_1 Wiring 306_1 Wiring 307_1 Wiring 307_1 Wiring 307_1 Transistor 309_1 Transistor 309_2 Transistor 311_1 Wiring 311_3 Wiring 31 _1 wiring 312_2 wiring 502 substrate 504 lower electrode 510 light emitting layer 514 upper electrode 531 hole injection layer 532 hole transport layer 533 electron transport layer 534 electron injection layer 552 sealing substrate 801 pixel circuit 802 pixel portion 804 drive circuit portion 804a gate driver 804b Source driver 806 Protection circuit 807 Terminal portion 852 Transistor 854 Transistor 862 Capacitance element 872 Light emitting element 2000 Touch panel 2001 Touch panel 2501 Display panel 2502 Pixel 2502t Transistor 2503c Capacitance element 2503g Scan line driver circuit 2503t Transistor 2509 FPC
2510 substrate 2510a insulating layer 2510b flexible substrate 2510c adhesive layer 2511 wiring 2519 terminal 2521 insulating layer 2528 partition 2550 light emitting element 2550R light emitting element 2560 sealing layer 2567BM light shielding layer 2567p antireflection layer 2567R colored layer 2570 substrate 2570a insulating layer 2570b flexible Substrate 2570c adhesive layer 2580 light emitting module 2590 substrate 2591 electrode 2592 electrode 2593 insulating layer 2594 wiring 2595 touch sensor 2597 adhesive layer 2598 wiring 2599 connection layer 2601 pulse voltage output circuit 2602 current detection circuit 2603 capacitor 2611 transistor 2612 transistor 2613 transistor 2621 electrode 2622 Electrode 3000 Light-emitting device 3001 Substrate 3003 Substrate 3005 Light-emitting element 3007 Sealing region 009 Sealing region 3011 Region 3013 Region 3014 Region 3015 Substrate 3016 Substrate 3016 Drying agent 3054 Display unit 3500 Multifunctional terminal 3502 Housing 3504 Display unit 3506 Camera 3508 Lighting 3600 Light 3602 Housing 3608 Lighting 3610 Speaker 8000 Display module 8001 Upper cover 8002 Lower cover 8003 FPC
8004 Touch sensor 8005 FPC
8006 Display panel 8009 Frame 8010 Printed circuit board 8011 Battery 9000 Housing 9001 Display unit 9003 Speaker 9005 Operation key 9006 Connection terminal 9007 Sensor 9008 Microphone 9050 Operation button 9051 Information 9052 Information 9053 Information 9054 Information 9055 Hinge 9100 Portable information terminal 9101 Portable information terminal 9102 Portable information terminal 9200 portable information terminal 9201 portable information terminal

Claims (16)

A light-emitting element having a light-emitting layer between a pair of electrodes,
The light emitting element is
The light emitting layer;
An electron transport layer in contact with the light emitting layer,
The light emitting layer has a host material and a guest material,
The electron transport layer has an electron transport material,
The guest material has an iridium complex,
The iridium complex is
Iridium metal,
A ligand coordinated to the iridium metal;
A substituent bonded to the ligand,
The substituent is a crosslinked cyclic hydrocarbon group having a mass number of 90 or more and less than 200,
The ligand has a nitrogen-containing five-membered heterocyclic skeleton,
The LUMO level of the electron transporting material, the LUMO level of the host material,
The difference is Ru der within 0.3eV, light emission element. A light-emitting element having a light-emitting layer between a pair of electrodes,
The light emitting element is
The light emitting layer;
An electron transport layer in contact with the light emitting layer,
The light emitting layer has a host material and a guest material,
The electron transport layer has an electron transport material,
The guest material has an iridium complex,
The iridium complex is
Iridium metal,
A ligand coordinated to the iridium metal;
A substituent bonded to the ligand,
The substituent is a crosslinked cyclic hydrocarbon group having a mass number of 90 or more and less than 200,
The ligand has an imidazole skeleton or a triazole skeleton,
The LUMO level of the electron transporting material, the LUMO level of the host material,
The difference is Ru der within 0.3eV, light emission element. A light-emitting element having a light-emitting layer between a pair of electrodes,
The light emitting element is
The light emitting layer;
An electron transport layer in contact with the light emitting layer,
The light emitting layer has a host material and a guest material,
The electron transport layer has an electron transport material,
Both the host material and the electron transporting material have a pyridine skeleton or a pyrimidine skeleton,
The guest material has an iridium complex,
The iridium complex is
Iridium metal,
A ligand coordinated to the iridium metal;
A substituent bonded to the ligand,
The substituent mass number Ru crosslinked cyclic hydrocarbon radical der less than 90 200, - emitting element. In claim 1 or claim 3 ,
It said substituents, you bond with the endocyclic nitrogen atom of the nitrogen-containing five-membered heterocyclic ring skeleton, light emission element. In claim 2 ,
It said substituents, you coupled to the imidazole skeleton or endocyclic nitrogen atoms of the triazole skeleton, light emission element. In any one of Claims 1 to 5 ,
It said substituents, that having a adamantyl group, - emitting element. In any one of Claims 1 thru | or 3 ,
The iridium complex, that have a tris-type structure, light emission element. In any one of Claims 1 thru | or 3 ,
The light emission from the light emitting layer is
That having a light emission spectrum peak in the blue wavelength band, light emission element. In any one of Claims 1 thru | or 3 ,
The iridium complex is a light-emitting element represented by the following general formula (G1).

(In the formula, Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. In addition, R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted group. Or any one of unsubstituted phenyl groups, and Q ¹ and Q ² each independently represent carbon or nitrogen, and in the case of carbon, they may have a substituent.) In any one of Claims 1 thru | or 3 ,
The iridium complex is a light-emitting element represented by the following general formula (G2).

(In the formula, Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. In addition, R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted group. Or any one of unsubstituted phenyl groups, and R ⁵ and R ⁶ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.) In any one of Claims 1 thru | or 3 ,
The iridium complex is a light-emitting element represented by the following general formula (G3).

(In the formula, Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. In addition, R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted group. Or any one of unsubstituted phenyl groups, and R ⁵ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.) In any one of Claims 1 thru | or 3 ,
The iridium complex is a light-emitting element represented by the following general formula (G4).

(In the formula, Z represents a tricycloalkyl group having 9 or 10 carbon atoms having a crosslinked structure. In addition, R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted group. Or any one of unsubstituted phenyl groups, and R ⁶ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.) In any one of Claim 9 thru | or Claim 11 ,
The tricycloalkyl group is a light-emitting element represented by the following structural formula (Z1) or (Z2).
The light emitting device according to any one of claims 1 to 13 ,
A color filter,
A light emitting device. A light emitting device according to any one of claims 1 to 13 , or a light emitting device according to claim 14 ,
A housing or touch sensor function;
Electronic equipment having A light emitting device according to any one of claims 1 to 13 , or a light emitting device according to claim 14 ,
A housing,
A lighting device.