Light-emitting device

Abstract

Provide a light-emitting element with a long life. Provide a light-emitting element that exhibits high luminous efficiency in a high brightness range. do. The light-emitting layer is disposed between a pair of electrodes, and the light-emitting layer contains a first organic compound, a second organic compound, and a The first organic compound includes an organic compound and a phosphorescent compound, and the first organic compound is represented by general formula (G0): The molecular weight of the first organic compound is 500 or more and 2000 or less, and the molecular weight of the second organic compound is 500 or more and 2000 or less. The organic compound is a light-emitting element that is a compound having electron transport properties. 1 and Ar 2 are each independently a fluorenyl group, a spirofluorenyl group, or a biphenyl group. represents a aryl group, and Ar 3 represents a substituent containing a carbazole skeleton. JPEG2023029394000057.jpg35165

Description

[Technical field]

[0001] The present invention relates to an electroluminescence (EL) The present invention relates to a light-emitting element (also referred to as an EL element), a light-emitting device, an electronic device, and a lighting device using the light-emitting element. do. [Background technology]

[0002] In recent years, research and development of EL elements has been actively conducted. The basic structure of an EL element is a pair of electrodes. A layer containing a luminescent material is sandwiched between electrodes. When a voltage is applied to this element, light is emitted. Light emission from the light-emitting substance can be obtained.

[0003] Since EL elements are self-emitting, they have higher pixel visibility than LCDs and no backlighting. It has the advantage of being suitable as a flat panel display element because it does not require a light source. Another major advantage of EL elements is that they can be made thin and lightweight. Another feature is its extremely fast response speed.

[0004] Since the EL element can be formed in a film shape, it is possible to obtain planar light emission. This makes it easy to form large-area elements. This is a feature that is difficult to obtain with point light sources such as fluorescent lamps, or linear light sources such as fluorescent lamps, and is therefore suitable for lighting, etc. It is also highly useful as a surface light source.

[0005] EL elements can be broadly classified according to whether the luminescent material is an organic compound or an inorganic compound. An organic electroluminescence device in which an organic compound is used as a light-emitting material and a layer containing the organic compound is provided between a pair of electrodes. In the case of a semiconductor, when a voltage is applied to the light-emitting element, electrons are emitted from the cathode and holes are emitted from the anode. The electrons are injected into the layers containing the organic compounds, causing a current to flow. The holes bring the organic compound to an excited state, and light is emitted from the excited organic compound. It is something.

[0006] The types of excited states that organic compounds can form are singlet excited states and triplet excited states. and the singlet excited state (S * ) is emitted from the triplet excited state (T * ) is called phosphorescence.

[0007] Regarding such light-emitting devices, there are problems depending on the material in improving the device characteristics. In order to overcome these problems, improvements to element structures and material development are being carried out. For example, Patent Document 1 describes an organic low-molecular-weight hole transport material, an organic low-molecular-weight electron transport material, and a phosphorescent dopant. An organic light emitting device having a mixed layer containing a pentacene is disclosed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 2004-515895 Summary of the Invention [Problem to be solved by the invention]

[0009] The development of organic EL elements still has room for improvement in terms of luminous efficiency, reliability, cost, etc. do.

[0010] In addition, in order to put organic EL elements to practical use in displays and lighting, organic EL elements have a long life. There is a demand for LEDs that are durable and have high luminous efficiency in the high brightness range.

[0011] In view of the above, an object of one embodiment of the present invention is to provide a light-emitting element with a long lifetime. An object of one embodiment is to provide a light-emitting element that exhibits high luminous efficiency in a high luminance region.

[0012] Another embodiment of the present invention is a highly reliable light-emitting device, an electronic device, and The present invention aims to provide a lighting device. [Means for solving the problem]

[0013] A light-emitting element according to one embodiment of the present invention has a light-emitting layer between a pair of electrodes. The first organic compound is a tertiary amine, a second organic compound, and a phosphorescent compound. and containing a fluorene skeleton, a spirofluorene skeleton, or a biphenylene skeleton. Two substituents containing a carbazole skeleton and one substituent containing a carbazole skeleton are directly attached to the nitrogen atom. The molecular weight of the first organic compound is 500 or more and 2000 or less. The second organic compound is a compound having an electron transporting property. By using this structure, it is possible to realize a light-emitting element with a long life. Light emitting devices exhibiting optical efficiency can be realized.

[0014] Specifically, one embodiment of the present invention has a light-emitting layer between a pair of electrodes, and the light-emitting layer is a first organic The compound includes a compound, a second organic compound, and a phosphorescent compound, the first organic compound being represented by the general formula (G 0), and the molecular weight of the first organic compound is 500 or more and 2000 or less. The second organic compound is a light-emitting element that is a compound having an electron transport property.

[0015] [ka]

[0016] In general formula (G0), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. represents a phenyl group, and Ar 3 represents a substituent containing a carbazole skeleton.

[0017] In one embodiment of the present invention, a light-emitting layer is provided between a pair of electrodes. The light-emitting layer contains a first organic compound a first organic compound represented by general formula (G1) The molecular weight of the first organic compound is 500 or more and 2000 or less. The second organic compound is a light-emitting element that is a compound having an electron transporting property.

[0018] [ka]

[0019] In general formula (G1), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. represents a substituted or unsubstituted phenylene group, biphenyldiyl group, n is 0 or 1, and A is a substituted or unsubstituted 3-carba Represents a zolyl group.

[0020] In one embodiment of the present invention, a light-emitting layer is provided between a pair of electrodes. The light-emitting layer contains a first organic compound a second organic compound and a phosphorescent compound, the first organic compound being represented by general formula (G2): The molecular weight of the first organic compound is 500 or more and 2000 or less. The second organic compound is a light-emitting element that is a compound having an electron transporting property.

[0021] [ka]

[0022] In general formula (G2), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. R represents a phenyl group. 1 ~R 4 and R 11 ~R 17 are each independently hydrogen, a carbon atom having 1 to 1 10 alkyl groups, unsubstituted or phenyl substituted with one or more alkyl groups having 1 to 10 carbon atoms a biphenyl group which is unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms; Represents Ar 4 is an alkyl group having 1 to 10 carbon atoms, an unsubstituted or Phenyl group substituted with one or more alkyl groups, unsubstituted or with one or more alkyl groups having 1 to 10 carbon atoms Substituted biphenyl group, or unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms It represents a terphenyl group.

[0023] In another embodiment of the present invention, a light-emitting layer is provided between a pair of electrodes. , a second organic compound, and a phosphorescent compound, the first organic compound being represented by general formula (G3): The molecular weight of the first organic compound is 500 or more and 2000 or less. The second organic compound is a light-emitting element that is a compound having an electron transporting property.

[0024] [ka]

[0025] In general formula (G3), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. R represents a phenyl group. 1 ~R 4 , R 11 ~R 17 , and R 21 ~R 25 are each independently , hydrogen, an alkyl group having 1 to 10 carbon atoms, or an unsubstituted or alkyl group having 1 to 10 carbon atoms or more substituted phenyl group, or unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms represents a biphenyl group.

[0026] In one embodiment of the present invention, in general formulae (G0) to (G3), Ar 1 and Ar 2 each independently represents a substituted or unsubstituted 2-fluorenyl group, a substituted or unsubstituted A spiro-9,9'-bifluoren-2-yl group or a biphenyl-4-yl group is preferred.

[0027] In one embodiment of the present invention, the hole-transport layer is in contact with the light-emitting layer, and the hole-transport layer is The third organic compound is an organic compound represented by general formula (G0), The molecular weight of the third organic compound is preferably 500 or more and 2,000 or less.

[0028] [ka]

[0029] In general formula (G0), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. represents a phenyl group, and Ar 3 represents a substituent containing a carbazole skeleton.

[0030] In one embodiment of the present invention, the hole-transport layer is in contact with the light-emitting layer, and the hole-transport layer is The third organic compound is an organic compound represented by general formula (G1), The molecular weight of the third organic compound is preferably 500 or more and 2,000 or less.

[0031] [ka]

[0032] In general formula (G1), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. represents a substituted or unsubstituted phenylene group, biphenyldiyl group, n is 0 or 1, and A is a substituted or unsubstituted 3-carba Represents a zolyl group.

[0033] In one embodiment of the present invention, the hole-transport layer is in contact with the light-emitting layer, and the hole-transport layer is The third organic compound is an organic compound represented by general formula (G2), The molecular weight of the third organic compound is preferably 500 or more and 2,000 or less.

[0034] [ka]

[0035] In general formula (G2), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. R represents a phenyl group. 1 ~R 4 and R 11 ~R 17 are each independently hydrogen, a carbon atom having 1 to 1 10 alkyl groups, unsubstituted or phenyl substituted with one or more alkyl groups having 1 to 10 carbon atoms a biphenyl group which is unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms; Represents Ar 4 is an alkyl group having 1 to 10 carbon atoms, an unsubstituted or Phenyl group substituted with one or more alkyl groups, unsubstituted or with one or more alkyl groups having 1 to 10 carbon atoms Substituted biphenyl group, or unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms It represents a terphenyl group.

[0036] In one embodiment of the present invention, the hole-transport layer is in contact with the light-emitting layer, and the hole-transport layer is The third organic compound is an organic compound represented by general formula (G3), The molecular weight of the third organic compound is preferably 500 or more and 2,000 or less.

[0037] [ka]

[0038] In general formula (G3), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. R represents a phenyl group. 1 ~R 4 , R 11 ~R 17 , and R 21 ~R 25 are each independently , hydrogen, an alkyl group having 1 to 10 carbon atoms, or an unsubstituted or alkyl group having 1 to 10 carbon atoms or more substituted phenyl group, or unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms represents a biphenyl group.

[0039] In one embodiment of the present invention, the third organic compound is the same as the first organic compound. is preferred.

[0040] In one embodiment of the present invention, the first organic compound and the second organic compound are exciplexes (ex It is preferable that the combination forms an exciplex.

[0041] In one embodiment of the present invention, the compound having an electron transport property is a π-electron-deficient heteroaromatic The π-electron deficient heteroaromatic compound is preferably a quinoxa Phosphorus skeleton, dibenzoquinoxaline skeleton, quinoline skeleton, pyrimidine skeleton, pyrazine skeleton, Examples of the compound include compounds containing a pyridine skeleton, a diazole skeleton, or a triazole skeleton.

[0042] Another embodiment of the present invention is a light-emitting device including the above-described light-emitting element in a light-emitting portion. One embodiment of the present invention is an electronic device including the light-emitting device in a display portion. The lighting device has a light emitting device as a light emitting section.

[0043] Since the light-emitting element of one embodiment of the present invention has a long lifetime, a highly reliable light-emitting device can be realized. Similarly, by applying one embodiment of the present invention, highly reliable electronic devices and lighting devices can be provided. It is possible to realize the above arrangement.

[0044] In addition, the light-emitting element of one embodiment of the present invention has high emission efficiency in a high luminance region. Similarly, by applying one embodiment of the present invention, a light-emitting device having a high light-emitting property can be realized. Highly efficient electronic devices and lighting devices can be realized.

[0045] In this specification, the term "light-emitting device" includes an image display device using a light-emitting element. In addition, the light emitting element is connected to a connector, such as anisotropic conductive film or TCP (Tape Cable). A module with a printed wiring board (Package A) attached, and a TCP Module with wiring board or COG (Chip On Glass) type for light emitting element According to the formula, all modules on which ICs (integrated circuits) are directly mounted are also included in the light-emitting device. Furthermore, it also includes light-emitting devices used in lighting fixtures and the like. Effect of the Invention

[0046] According to one embodiment of the present invention, a light-emitting element with a long lifetime can be provided. In addition, in one embodiment of the present invention, a light-emitting device, an electronic device, and a lighting device having high light-emitting properties can be provided. A light-emitting element that exhibits high luminous efficiency in a high luminance region can be provided. It is possible to provide a light-emitting device, an electronic device, and a lighting device with high light efficiency. [Brief description of the drawings]

[0047] [Figure 1] 1A and 1B illustrate an example of a light-emitting element according to one embodiment of the present invention. [Diagram 2]1A and 1B illustrate an example of a light-emitting element according to one embodiment of the present invention and an exciplex. [Diagram 3] 1 illustrates an example of a light-emitting device according to one embodiment of the present invention. [Figure 4] 1 illustrates an example of a light-emitting device according to one embodiment of the present invention. [Diagram 5] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 6] FIG. 1 illustrates an example of a lighting device. [Figure 7] 1A and 1B are diagrams showing light-emitting elements according to an embodiment of the present invention; [Figure 8] FIG. 1 shows luminance-current efficiency characteristics of the light-emitting element of Example 1. [Figure 9] FIG. 2 shows voltage-luminance characteristics of the light-emitting element of Example 1. [Figure 10] FIG. 1 shows luminance vs. external quantum efficiency characteristics of the light-emitting element of Example 1. [Figure 11] FIG. 13 shows the results of a reliability test of the light-emitting element of Example 1. [Figure 12] FIG. 13 shows luminance-current efficiency characteristics of the light-emitting element of Example 2. [Figure 13] FIG. 13 shows voltage-luminance characteristics of the light-emitting element of Example 2. [Figure 14] FIG. 13 shows luminance-power efficiency characteristics of the light-emitting element of Example 2. [Figure 15] FIG. 13 shows luminance vs. external quantum efficiency characteristics of the light-emitting element of Example 2. [Figure 16] FIG. 13 shows the results of a reliability test of the light-emitting element of Example 2. [Figure 17] FIG. 13 shows luminance-current efficiency characteristics of the light-emitting element of Example 3. [Figure 18] FIG. 13 shows voltage-luminance characteristics of the light-emitting element of Example 3. [Figure 19] FIG. 13 shows luminance-power efficiency characteristics of the light-emitting element of Example 3. [Figure 20] FIG. 13 shows luminance vs. external quantum efficiency characteristics of the light-emitting element of Example 3. [Figure 21]FIG. 1 shows a 1H NMR chart of N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF). [Figure 22] FIG. 1 shows the absorption spectrum and emission spectrum of a toluene solution of PCBBiF. [Diagram 23] FIG. 1 shows the absorption and emission spectra of a thin film of PCBBiF. [Figure 24] FIG. 1 shows a 1H NMR chart of N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBBiSF). [Diagram 25] FIG. 1 shows the absorption spectrum and emission spectrum of a toluene solution of PCBBiSF. [Figure 26] FIG. 1 shows the absorption and emission spectra of a thin film of PCBBiSF. [Figure 27] FIG. 13 shows voltage-current characteristics of the light-emitting element of Example 4. [Figure 28] FIG. 13 shows luminance-external quantum efficiency characteristics of the light-emitting element of Example 4. [Figure 29] FIG. 13 shows an emission spectrum of the light-emitting element of Example 4. [Diagram 30] FIG. 13 shows the results of a reliability test of the light-emitting element of Example 4. [Diagram 31] FIG. 13 shows luminance-current efficiency characteristics of the light-emitting element of Example 5. [Diagram 32] FIG. 13 shows voltage-luminance characteristics of the light-emitting element of Example 5. [Diagram 33] FIG. 13 shows luminance vs. external quantum efficiency characteristics of the light-emitting element of Example 5. [Diagram 34] FIG. 13 shows the results of a reliability test of the light-emitting element of Example 5. [Diagram 35] FIG. 13 shows luminance-current efficiency characteristics of the light-emitting element of Example 6. [Diagram 36] FIG. 13 shows voltage-luminance characteristics of the light-emitting element of Example 6. [Figure 37]FIG. 13 shows luminance-external quantum efficiency characteristics of the light-emitting element of Example 6. [Figure 38] FIG. 13 shows the results of a reliability test of the light-emitting element of Example 6. [Figure 39] FIG. 13 shows luminance-current efficiency characteristics of the light-emitting element of Example 7. [Diagram 40] FIG. 13 shows voltage-luminance characteristics of the light-emitting element of Example 7. [Diagram 41] FIG. 13 shows luminance-external quantum efficiency characteristics of the light-emitting element of Example 7. [Diagram 42] FIG. 13 shows the results of a reliability test of the light-emitting element of Example 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] The embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiment, and various changes and modifications may be made in the form and details without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the above-mentioned invention can be obtained by the following embodiments. The present invention should not be construed as being limited to the contents described below. The same reference numerals are used in different drawings to indicate the same parts or parts having similar functions. A repeated explanation will be omitted.

[0049] (Embodiment 1) In this embodiment, a light-emitting element of one embodiment of the present invention will be described with reference to FIG.

[0050] The light-emitting element exemplified in this embodiment has a pair of electrodes and a light-emitting element provided between the pair of electrodes. and a layer containing an organic compound (EL layer).

[0051] The light-emitting element shown in FIG. 1A includes an EL layer 20 between a first electrode 201 and a second electrode 205. In this embodiment, the first electrode 201 functions as an anode, and the second electrode 20 5 functions as the cathode.

[0052] A voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 201 and the second electrode 205. Then, holes are injected into the EL layer 203 from the first electrode 201 side, and electrons are injected into the EL layer 203 from the second electrode 205 side. The injected electrons and holes recombine in the EL layer 203, and the EL layer 20 The luminescent substance contained in 3 emits light.

[0053] The EL layer 203 has at least a light-emitting layer 303. 303 includes a first organic compound, a second organic compound, and a phosphorescent compound.

[0054] In this embodiment, a phosphorescent compound is used as a guest material that is a light-emitting substance. The first organic compound and the second organic compound that are contained in the light-emitting layer at a higher ratio are used as the gate electrode. The material in which the substrate material is dispersed is called the host material.

[0055] In the light-emitting layer of the light-emitting element of this embodiment, the content of the host material is higher than the content of the guest material. By dispersing the guest material in the host material, crystallization of the light-emitting layer is suppressed. In addition, the concentration quenching caused by the high concentration of the guest material can be suppressed, and the luminescence The luminous efficiency of the element can be increased.

[0056] The first organic compound is a tertiary amine and has a fluorene skeleton, a spirofluorene skeleton, or The compound has two substituents containing a biphenylene skeleton and one substituent containing a carbazole skeleton. and a substituent are each directly bonded to a nitrogen atom of the first organic compound. The molecular weight of the second organic compound is 500 or more and 2000 or less. It is a mixture.

[0057] The tertiary amine has a simple structure, a phenyl group, as a substituent bonded directly to the nitrogen atom. or alkylphenyl groups, but instead contain biphenyl, fluorenyl, or spirof groups. The introduction of fluorenyl groups makes it chemically stable, and it has a long life and good reproducibility. In addition, since the tertiary amine has a carbazole skeleton, it is thermally The tertiary amine has high stability and improved reliability. Since it has a spirofluorenylamine skeleton or a biphenylamine skeleton, it has high hole In addition to its high transport and electron blocking properties, it has three-fold higher molecular weight than amines that contain a naphthalene skeleton. Because of its high doublet excitation energy, it also has excellent exciton blocking properties. Therefore, it is possible to prevent leakage of electrons and diffusion of excitons, and realize a light-emitting element with high luminous efficiency. do.

[0058] In the following, the first organic compound, the second organic compound, and the phosphorescent compound contained in the light-emitting layer 303 will be described. Each of the materials that can be used as the mixture will be described in detail.

[0059] <First organic compound> The first organic compound is a compound represented by the general formula (G0), and the molecular weight of the first organic compound is is between 500 and 2000 inclusive.

[0060] [ka]

[0061] In general formula (G0), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. represents a phenyl group, and Ar 3 represents a substituent containing a carbazole skeleton.

[0062] In the general formula (G0), a fluorenyl group, a spirofluorenyl group, or a biphenyl group is In the case where the group has a substituent, the substituent may be an alkyl group having 1 to 10 carbon atoms, an unsubstituted or Phenyl group substituted with one or more alkyl groups having 1 to 10 carbon atoms, unsubstituted or Biphenyl group substituted with one or more alkyl groups having 1 to 10 carbon atoms, The terphenyl group may be substituted with one or more aryl groups. The compound represented by the formula (G0) has a higher hole transporting property and an electron blocking property than the compound without a substituent. The hole transporting and electron blocking properties are unlikely to decrease (similarly high hole transporting and electron blocking properties , and can exhibit exciton blocking properties).

[0063] Also, Ar 3 As examples, substituted or unsubstituted (9H-carbazol-9-yl)phenyl a substituted or unsubstituted (9H-carbazol-9-yl)biphenyl group; or unsubstituted (9H-carbazol-9-yl)terphenyl group, substituted or unsubstituted (9-aryl-9H-carbazol-3-yl)phenyl groups, substituted or unsubstituted ( 9-aryl-9H-carbazol-3-yl)biphenyl group, substituted or unsubstituted ( 9-aryl-9H-carbazol-3-yl)terphenyl group, substituted or unsubstituted Specific examples of aryl groups include 9-aryl-9H-carbazol-3-yl groups. Examples of the phenyl group include an unsubstituted phenyl group or a phenyl group substituted with one or more alkyl groups having 1 to 10 carbon atoms; A biphenyl group substituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms, an unsubstituted or Examples of the alkyl group include a terphenyl group substituted with one or more alkyl groups having 1 to 10 carbon atoms. The above-mentioned Ar 3 When the group has a substituent, the substituent is preferably an alkyl group having 1 to 10 carbon atoms. phenyl group, unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms; or a biphenyl group substituted with one or more alkyl groups having 1 to 10 carbon atoms, and terphenyl groups substituted with one or more alkyl groups having a carbon number of 1 to 10. group, the compound represented by general formula (G0) has high hole transporting property, electron blocking property, and Furthermore, the loss of exciton blocking properties can be suppressed.

[0064] The first organic compound contained in the light-emitting layer 303 is a compound represented by the following general formula (G1): Things are preferred.

[0065] [ka]

[0066] In general formula (G1), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. represents a substituted or unsubstituted phenylene group, biphenyldiyl group, n is 0 or 1, and A is a substituted or unsubstituted 3-carba Represents a zolyl group.

[0067] An example of a specific structure of α in general formula (G1) is shown in structural formula (1-1) to structural formula (1-9). ) as shown in

[0068] [ka]

[0069] The first organic compound contained in the light-emitting layer 303 is a compound represented by the following general formula (G2): Things are more preferable.

[0070] [ka]

[0071] In general formula (G2), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. R represents a phenyl group. 1 ~R 4 and R 11 ~R 17 are each independently hydrogen, a carbon atom having 1 to 1 10 alkyl groups, unsubstituted or phenyl substituted with one or more alkyl groups having 1 to 10 carbon atoms a biphenyl group which is unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms; Represents Ar 4 is an alkyl group having 1 to 10 carbon atoms, an unsubstituted or Phenyl group substituted with one or more alkyl groups, unsubstituted or with one or more alkyl groups having 1 to 10 carbon atoms Substituted biphenyl group, or unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms It represents a terphenyl group.

[0072] The first organic compound contained in the light-emitting layer 303 is a compound represented by the following general formula (G3). The material is particularly preferred.

[0073] [ka]

[0074] In general formula (G3), Ar 1 and Ar 2 are each independently a substituted or unsubstituted fluoro a substituted or unsubstituted bifluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted bifluorenyl group. R represents a phenyl group. 1 ~R 4 , R 11 ~R 17 and R 21 ~R 25 are each independently Hydrogen, alkyl group having 1 to 10 carbon atoms, unsubstituted or alkyl group having 1 to 10 carbon atoms A phenyl group substituted with the above-mentioned alkyl group or an unsubstituted or substituted with one or more alkyl groups having 1 to 10 carbon atoms. It represents a biphenyl group.

[0075] Ar 1 and Ar 2 each independently represents a substituted or unsubstituted 2-fluorenyl group, or an unsubstituted spiro-9,9'-bifluoren-2-yl group, or a biphenyl-4- Tertiary amines having any of these skeletons have high positive charge and negative charge. In addition to having hole transport properties and high electron blocking properties, it has three-fold higher molecular weight than amines that contain a naphthalene skeleton. Since the doublet excitation energy is high, it also has excellent exciton blocking properties and is preferable. Among the fluorenyl, fluorenyl, and spirofluorenyl groups, those at these substitution positions are acceptable. It is easy to achieve, inexpensive, and desirable.

[0076] In general formula (G2) and general formula (G3), R 1 ~R 4 , R 11 ~R 17 and R 21 ~R 25Examples of specific structures are shown in structural formulas (2-1) to (2-17). In each of the above general formulae, a fluorenyl group, a spirofluorenyl group, or a biphenyl group When the group has a substituent, the substituent is an alkyl group having 1 to 10 carbon atoms, an unsubstituted or or a phenyl group substituted with one or more alkyl groups having 1 to 10 carbon atoms, or an unsubstituted or Examples of the specific structures include biphenyl groups substituted with one or more alkyl groups having a molecular weight of from 1 to 10. Examples of the substituent include those shown in structural formulas (2-2) to (2-17). In addition, Ar in the general formula (G2) 4 An example of a specific structure is the structural formula (2-2) to Examples of the substituent include those shown in structural formula (2-17).

[0077] [ka]

[0078] Specific examples of the organic compound represented by the general formula (G0) include the organic compounds represented by the structural formulas (101) to (1 42) However, the present invention is not limited to these. do not have.

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] <Second organic compound> The second organic compound is a compound having an electron transporting property. The heteroaromatic aromatic compounds are π-electron deficient, such as nitrogen-containing heteroaromatic aromatic compounds, and quinoline or Metal complexes having a benzoquinoline skeleton, oxazole-based ligands or thiazole-based ligands A metal complex having the formula (I) can be used.

[0089] Specifically, bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation Name: BeBq 2 ), 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 Name: Zn(BOX) 2 ), bis[2-(2-benzothiazolyl)phenolato]zinc(II ) (Abbreviation: Zn(BTZ) 2 ), metal complexes 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 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-benzimidazol Heterocyclic compounds having a polyazole skeleton, such as mDBTBIm-II, [3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline ( Abbreviation: 2mDBTPDBq-II), 7-[3-(dibenzothiophen-4-yl)phenyl nyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3 -(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation : 6mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl nyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II ), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[ f, h]quinoxaline (abbreviation: 2mCzBPDBq) or dibenzo Heterocyclic compounds with quinoxaline skeleton, 4,6-bis[3-(phenanthrene-9- 4,6-bis[3-(9yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4,6-Bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mD BTP2Pm-II) and other compounds with diazine skeletons (pyrimidine skeletons and pyrazine skeletons) The heterocyclic compound, 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 3,5DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]be benzene (abbreviation: TmPyPB), 3,3',5,5'-tetra[(m-pyridyl)-phenyl Heterocyclization of pyridine skeleton such as [4-phenyl-3-yl]biphenyl (abbreviation: BP4mPy) Among the above, compounds having a quinoxaline skeleton or a dibenzoquinoxaline skeleton are preferred. Heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a pyridine skeleton The compound is preferable because of its good reliability.

[0090] <Phosphorescent compound> An example of a phosphorescent compound that can be used in the light-emitting layer 303 is as follows. The phosphorescent compound with an emission peak at 520 nm is tris{2-[5-(2-methylphenyl)- 4-(2,6-dimethylphenyl)-4H-1,2,4-triazole -3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mppt z-dmp) 3 ]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-trimethyl Riazolato)iridium(III) (abbreviation: [Ir(Mptz) 3 ]), Tris[4-( 3-Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato ]Iridium(III) (abbreviation: [Ir(iPrptz-3b) 3 ]) such as 4H-T Organometallic iridium complexes with a triazole skeleton and tris[3-methyl-1-(2-methylphenyl)phenyl] (III)-5-phenyl-1H-1,2,4-triazolato]iridium(III ) (Abbreviation: [Ir(Mptz1-mp) 3 ]), tris(1-methyl-5-phenyl-3 -propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir( Prptz1-Me) 3 ]) complexes and fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl- 1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi) 3 ]),to Tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenane Trizinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) 3 ]) Organometallic iridium complexes with imidazole skeletons such as bis[2-(4',6'-diphenylphosphine] Fluorophenyl)pyridinato-N,C 2’ ]Iridium(III) tetrakis(1-pi FIr6, bis[2-(4',6'-difluorophenyl ) Pyridinato-N,C 2’ ]Iridium(III) picolinate (abbreviation: FIrpic) , bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) picolinate (abbreviation: [Ir(CF 3 ppy) 2 (pic) ]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Iridescent Fluorine(III) acetylacetonate (abbreviation: FIracac) An example of an organometallic iridium complex is a phenylpyridine derivative having the above-mentioned structure as a ligand. Among these, organometallic iridium complexes with a 4H-triazole skeleton have excellent reliability and luminescence properties. This is particularly preferred due to its excellent efficiency.

[0091] For example, examples of phosphorescent compounds having an emission peak at 520 nm to 600 nm include: Tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir (mppm) 3 ]), tris(4-t-butyl-6-phenylpyrimidinato)iridium (III) (Abbreviation: [Ir(tBuppm) 3 ]), (acetylacetonato)bis(6- Methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) 2 (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenyl Rupyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) 2 (acac) ]), (acetylacetonato)bis[4-(2-norbornyl)-6-phenylpyrimidinyl NatO]iridium(III) (endo-, exo-mixture) (abbreviation: [Ir(nbpp m) 2 (acac)]), (acetylacetonato)bis[5-methyl-6-(2-methyl phenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpm ppm) 2 (acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinium) dinato)iridium(III) (abbreviation: [Ir(dppm) 2 (acac)]) Organometallic iridium complexes with pyrimidine skeletons and (acetylacetonato)bis(3, 5-Dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mpp r-Me) 2 (acac)]), (acetylacetonato)bis(5-isopropyl-3- Methyl-2-phenylpyrazinate)iridium(III) (abbreviation: [Ir(mppr-i P) 2 Organometallic iridium complexes with pyrazine skeletons such as (acac)] and Tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(p py) 3 ]), bis(2-phenylpyridinato-N,C 2’ ) Iridium(III) acetone Ir(ppy) 2 (acac)]), bis(benzo[h]ki Iridium(III) acetylacetonate (abbreviation: [Ir(bzq) 2 (a cac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir (bzq) 3 ]), tris(2-phenylquinolinato-N,C 2’ ) Iridium (III ) (Abbreviation: [Ir(pq) 3 ]), bis(2-phenylquinolinato-N,C 2’ ) Iridi Ir(III) acetylacetonate (abbreviation: [Ir(pq) 2 (acac)]) In addition to the organometallic iridium complexes with pyridine skeletons, tris(acetylacetonato)( Monophenanthroline) terbium(III) (abbreviation: [Tb(acac) 3 (Phen Among the above, rare earth metal complexes having a pyrimidine skeleton are Organometallic iridium complexes are particularly preferred due to their outstanding reliability and luminous efficiency.

[0092] For example, examples of phosphorescent compounds having an emission peak at 600 nm to 700 nm include: (Diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato] Iridium(III) (abbreviation: [Ir(5mdppm) 2 (dibm)]), bis[4, 6-Bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium( III) (abbreviation: [Ir(5mdppm) 2 (dpm)]), bis[4,6-di(naphthalene [(1-phenyl-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III)(abbreviation :[Ir(d1npm) 2 Organometallic iridium with pyrimidine skeleton such as (dpm)] (acetylacetonato)bis(2,3,5-triphenylpyrazinate)iodine complexes Ir(tppr) 2 (acac)]), Bis(2,3,5 -Triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [ Ir(tppr) 2 (dpm)]), (acetylacetonato)bis[2,3-bis(4- [Fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) 2 Organometallic iridium complexes with pyrazine skeletons such as tris( 1-Phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pi q) 3 ]), bis(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) A Cetylacetonate (abbreviation: [Ir(piq) 2 (acac)]) In addition to organometallic iridium complexes with White such as triethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) Gold complexes and tris(1,3-diphenyl-1,3-propanedionato)(monophenanthate Europium(III) (abbreviation: [Eu(DBM) 3 (Phen)]), Tris [1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthrol Europium(III) (abbreviation: [Eu(TTA) 3 (Phen)] Among the above, organometallic iridium complexes having a pyrimidine skeleton are The complex is particularly preferred because of its outstanding reliability and luminous efficiency. The organometallic iridium complex having the above structure can emit red light with good chromaticity.

[0093] The light-emitting layer includes the first organic compound, the second organic compound, and the phosphorescent compound. By applying the light-emitting layer, a light-emitting element having a long life can be manufactured. Thus, a light-emitting element that exhibits high luminous efficiency in a high luminance region can be manufactured.

[0094] In addition, by providing multiple light-emitting layers and making each layer emit a different color, As a whole, it is possible to obtain light of a desired color. For example, in a light-emitting device having two light-emitting layers, In the present invention, the luminescent color of the first luminescent layer and the luminescent color of the second luminescent layer are made to have a complementary color relationship. It is also possible to obtain a light emitting element that emits white light as a whole. refers to the relationship between colors that become achromatic when mixed. In other words, it is a color that emits colors that are complementary to each other. By mixing the light from these materials, white light can be obtained. The same applies to the case of a light-emitting element having the above-mentioned light-emitting layers. In the light-emitting device, at least one light-emitting layer has the above-mentioned structure (the first organic compound, the second organic compound, The present invention is not limited to the above, and may be applied to all light-emitting layers as long as the above-mentioned compound and the phosphorescent compound are included in the light-emitting layer. It is okay if it is.

[0095] In addition, the EL layer 203 is formed of a material having a high hole injection property and a material having a high hole transport property as a layer other than the light emitting layer. a material with high electron transportability, a material with high electron injection properties, or a bipolar material. The layer may further include a layer containing a polar substance (a substance having high electron transport and hole transport properties). The EL layer 203 can be made of known materials, including low molecular weight compounds and high molecular weight compounds. Any of the above compounds may be used, and may contain inorganic compounds.

[0096] The light-emitting element shown in FIG. 1B has an EL layer 20 between a first electrode 201 and a second electrode 205. 3, and the EL layer 203 includes a hole injection layer 301, a hole transport layer 302, a light emitting layer 303, An electron transport layer 304 and an electron injection layer 305 are laminated in this order from the first electrode 201 side. There are.

[0097] The light-emitting element shown in FIG. 1C has an EL layer 20 between a first electrode 201 and a second electrode 205. 3, and further includes an intermediate layer 207 between the EL layer 203 and the second electrode 205.

[0098] A specific example of the configuration of the intermediate layer 207 is shown in FIG. The intermediate layer 207 has at least an electron emitting layer 308 as a layer other than the charge generating region 308. The semiconductor device may further include a layer 307 and an electron injection buffer layer 306. has an EL layer 203 on a first electrode 201, and an intermediate layer 207 on the EL layer 203; The second electrode 205 is provided on the intermediate layer 207. In FIG. 1(D), From the EL layer 203 side, the electron injection buffer layer 306, the electron relay layer 307, and the charge A generation area 308 is provided.

[0099] A voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 201 and the second electrode 205. Then, holes and electrons are generated in the charge generating region 308, and the holes are transferred to the second electrode 205. The electrons move to the electron relay layer 307. The electron relay layer 307 has high electron transport properties. This layer quickly transfers electrons generated in the charge generation region 308 to the electron injection buffer layer 306. The electron injection buffer layer 306 reduces the electron injection barrier of the EL layer 203 and This layer enhances the efficiency of electron injection into the charge generating region 308. The LUMO(L owest Unoccupied Molecular Orbital orbital) level.

[0100] The electron relay layer 307 is made of a material constituting the charge generating region 308 and an electron injection buffer. The materials that make up layer 306 react at the interface, causing interactions that impair the functions of each other. It can be prevented.

[0101] As shown in FIG. 1E and FIG. 1F, a light-emitting element is formed between a first electrode 201 and a second electrode 205. In this case, an intermediate layer may be provided between the stacked EL layers. For example, the light-emitting element shown in FIG. The intermediate layer 207 is disposed between the first EL layer 203a and the second EL layer 203b. The light emitting element has n EL layers (n is a natural number of 2 or more), and the mth EL layer 203(m) and the (m+1)th EL layer 203(m+1). In a light-emitting element according to one embodiment of the present invention having a plurality of EL layers, at least one of the EL layers The light-emitting layer has the above-mentioned structure (containing the first organic compound, the second organic compound, and the phosphorescent compound). The above-mentioned configuration may be applied to all the light-emitting layers included in the EL layer. .

[0102] The electric field in the intermediate layer 207 provided between the EL layer 203(m) and the EL layer 203(m+1) The behavior of electrons and holes will be described. When a voltage higher than the threshold voltage of the molecule is applied, holes and electrons are generated in the intermediate layer 207, and the positive The holes move to the EL layer 203(m+1) provided on the second electrode 205 side, and the electrons move to the EL layer 203(m+1) provided on the second electrode 205 side. Moves to the EL layer 203(m) provided on the electrode 201 side. Injected into the EL layer 203(m+1) The holes are recombined with the electrons injected from the second electrode 205 side, and the EL layer 203 ( The light-emitting material contained in the EL layer 203(m+1) emits light. The electrons injected into the EL layer 203(m) emit light. The electrons recombine with the holes injected from the first electrode 201 side and are contained in the EL layer 203(m). The luminescent material emits light. Therefore, the holes and electrons generated in the intermediate layer 207 are Light emission occurs in the different EL layers.

[0103] In addition, when the EL layers are provided in contact with each other, the same structure as the intermediate layer is formed between them. For example, a charge generating region may be provided on one side of the EL layer. When the light-emitting layer 14 is formed, an EL layer can be provided in contact with the surface of the light-emitting layer 14.

[0104] In addition, by making the emission color of each EL layer different, the light-emitting device as a whole can have a desired color. For example, in a light-emitting element having two EL layers, the first By making the emission color of the first EL layer and the emission color of the second EL layer complementary to each other, It is also possible to obtain a light-emitting device that emits white light as a whole. The same applies to the case of a light emitting element having a

[0105] 1(B) to (E) can be used in combination with each other. For example, FIG. 1(F) An intermediate layer 207 may be provided between the second electrode 205 and the EL layer 203(n).

[0106] Examples of materials that can be used for each layer are given below. Each layer is not limited to a single layer. Two or more layers may be laminated.

[0107] <anode> The electrode functioning as the anode (first electrode 201 in this embodiment) is made of a conductive metal. The layer can be formed by using one or more of a material such as a conductive material, an alloy, or a conductive compound. It is preferable to use a material with a large charge (4.0 eV or more). For example, indium tin oxide Indium tin oxide (ITO), a material containing silicon or silicon oxide Indium tin oxide, indium zinc oxide, tungsten oxide and zinc oxide Indium oxide, graphene, gold, platinum, nickel, tungsten, chromium, molybdenum , iron, cobalt, copper, palladium, or nitrides of metallic materials (e.g., titanium nitride). Can be obtained.

[0108] In addition, when the anode contacts the charge generating region, various conductive materials can be used without considering the magnitude of the work function. For example, aluminum, silver, and alloys containing aluminum can be used. There can be.

[0109] <cathode> The electrode functioning as a cathode (the second electrode 205 in this embodiment) is made of a conductive metal. The material may be formed by using one or more of a conductive material, an alloy, a conductive compound, etc. It is preferable to use a material with a small electron transport potential (3.8 eV or less). For example, Elements belonging to group 1 or group 2 (e.g., alkali metals such as lithium and cesium, calcium , alkaline earth metals such as strontium, magnesium, etc.), alloys containing these elements (e.g. For example, rare earth metals such as Mg-Ag, Al-Li), europium, ytterbium, etc. For example, alloys containing rare earth metals, aluminum, silver, etc. can be used.

[0110] In addition, when the cathode is in contact with the charge generating region, various conductive materials can be used without considering the magnitude of the work function. For example, ITO, indium containing silicon or silicon oxide, Tin oxide and the like can also be used.

[0111] The light-emitting element has a conductive film on one side, either the anode or the cathode, that transmits visible light, and the other side that reflects visible light. Alternatively, both the anode and the cathode may be conductive films that transmit visible light. A certain configuration is also possible.

[0112] The conductive film that transmits visible light is, for example, indium oxide, ITO, indium zinc oxide, The insulating layer can be formed of zinc oxide, zinc oxide doped with gallium, or the like. Platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, Alternatively, metal materials such as titanium, or nitrides of these metal materials (e.g., titanium nitride), etc. The graphene or the like can be used by forming the graphene or the like thin enough to have light-transmitting properties. You may use it.

[0113] The conductive film that reflects visible light is made of, for example, aluminum, gold, platinum, silver, nickel, tungsten, etc. Metallic materials such as zinc, chromium, molybdenum, iron, cobalt, copper, or palladium, aluminum Aluminum and titanium alloys, aluminum and nickel alloys, aluminum and neodymium alloys Alloys containing aluminum, such as gold (aluminum alloys), or silver, such as silver-copper alloys The electrode can be formed using an alloy. An alloy of silver and copper is preferable because of its high heat resistance. Even if lanthanum, neodymium, germanium, etc. are added to the above metal materials and alloys, good.

[0114] The electrodes may be formed by vacuum deposition or sputtering. When a paste or the like is used, a coating method or an ink-jet method may be used.

[0115] <Hole injection layer 301> The hole injection layer 301 is a layer containing a substance with high hole injection properties.

[0116] Examples of materials with high hole injection properties include molybdenum oxide, titanium oxide, and vanadium oxide. Oxide, Rhenium Oxide, Ruthenium Oxide, Chromium Oxide, Zirconium Oxide, Huff Gold oxide, tantalum oxide, silver oxide, tungsten oxide, manganese oxide, etc. Metal oxides and the like can be used.

[0117] In addition, phthalocyanine (abbreviation: H 2 Pc), copper(II) phthalocyanine (abbreviation: CuPc ) and other phthalocyanine compounds can be used.

[0118] In addition, the low molecular weight organic compound 4,4',4''-tris(N,N-diphenylamino) ) Triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl) (N-phenylamino)triphenylamine (abbreviation: MTDATA), 4 ,4'-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl DPAB, 4,4'-bis(N-{4-[N'-(3-methylphenyl)- N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTP D) 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamine N-(9-phenylcarbazol-3-yl)benzene (abbreviation: DPA3B) )-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3, 6-Bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9- Phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-( 9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: P Aromatic amine compounds such as CzPCN1) can be used.

[0119] In addition, poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenyl PVTPA), poly[N-(4-{N'-[4-(4-diphenylamine N'-phenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide Name: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis( Poly(3,4-phenyl)benzidine (abbreviation: Poly-TPD) and other polymer compounds. ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS), Polyaniline / poly(styrenesulfonic acid) (PAni / PSS) and other acid-added polymers A child compound can be used.

[0120] The hole injection layer 301 may also serve as a charge generating region. When the charge generation region is the charge generation region, various conductive materials can be used for the anode without considering the work function. The materials constituting the charge generating region will be described later.

[0121] <Hole transport layer 302> The hole transport layer 302 is a layer containing a substance having a high hole transporting property. In particular, the material may be one that transports holes rather than electrons. -6 cm 2 / Vs or later Preferably, the material has a hole mobility above 100 nm.

[0122] The hole transport layer 302 is formed of an organic compound represented by any one of the general formulas (G0) to (G3) described above. Both the hole transport layer 302 and the light emitting layer 303 may be formed of a compound represented by the above general formula ( By applying an organic compound represented by any one of (G0) to (G3), hole injection can be achieved. This not only reduces the barrier to entry for light emission, but also increases the light emission efficiency and reduces the driving voltage. That is, by adopting such a configuration, it is possible to obtain high light emission in the high brightness region as described above. Not only can the efficiency be maintained, but the driving voltage can also be kept low. A light-emitting element with little loss in power efficiency due to voltage loss even in luminance, i.e., a light-emitting element with high power efficiency ( In particular, from the viewpoint of the hole injection barrier, It is preferred that the hole transport layer 302 and the light emitting layer 303 contain the same organic compound.

[0123] Other examples of materials with high hole transport properties include 4,4'-bis[N-(1-naphthyl) N,N'-biphenyl (abbreviation: NPB or α-NPD), S(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4 '-diamine (abbreviation: TPD), 4-phenyl-4'-(9-phenylfluorene-9- 4,4'-bis[N-(9,9-diyl)triphenylamine (abbreviation: BPAFLP), Methylfluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: DFLDPB i) 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenyl An aromatic amine compound such as bis(phenylamino)biphenyl (abbreviation: BSPB) can be used. do.

[0124] In addition, 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 9-[4-(1 0-Phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 9-Phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-cal Carbazole derivatives such as PCzPA (abbreviation: PCzPA) can be used.

[0125] In addition, 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t- BuDNA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10 - Use of aromatic hydrocarbon compounds such as diphenylanthracene (abbreviation: DPAnth) This can be done.

[0126] In addition, polymer compounds such as PVK, PVTPA, PTPDMA, and Poly-TPD are used. It is possible.

[0127] <Electron transport layer 304> The electron transporting layer 304 is a layer containing a substance with a high electron transporting property.

[0128] As a substance having a high electron transporting property, an organic compound having a higher electron transporting property than a hole transporting property may be used. , especially, 10 -6 cm 2 It is preferable that the material has an electron mobility of .beta. / Vs or more.

[0129] The electron transport layer 304 contains the second organic compound (having electron transport properties) contained in the light emitting layer 303. Compounds) can be applied.

[0130] In addition, the electron transport layer 304 may contain, for example, tris(8-quinolinolato)aluminum ( III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum (I II) (Abbreviation: Almq 3 ) and other metal complexes can be used.

[0131] Also, bathophenanthroline (abbreviated as BPhen) and bathocuproine (abbreviated as BCP) , 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl phenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), 4,4'-bis( 5-Methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) and other heteroaromatic Aromatic compounds can be used.

[0132] In addition, poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexyl Fluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF- Py), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2' -bipyridine-6,6'-diyl) (abbreviation: PF-BPy) and other polymer compounds are used. It is possible.

[0133] <Electron injection layer 305> The electron injection layer 305 is a layer containing a substance with high electron injection properties.

[0134] Examples of materials with high electron injection properties include lithium, cesium, calcium, and lithium oxide. Lithium carbonate, Cesium carbonate, Lithium fluoride, Cesium fluoride, Calcium fluoride fluoride, erbium fluoride, and other alkali metals, alkaline earth metals, rare earth metals, or Compounds (oxides, carbonates, halides, etc.) of the above can be used.

[0135] The electron injection layer 305 contains the above-mentioned substance having high electron transport properties and a donor substance. For example, magnesium (Mg) may be contained in Alq to form the electron injection layer 3. When a substance having high electron transport properties and a donor substance are included, The mass ratio of the donor substance to the high-temperature substance is preferably 0.001 to 0.1. I wish.

[0136] Donor substances include lithium, cesium, magnesium, calcium, and erbium. , ytterbium, lithium oxide, calcium oxide, barium oxide, magnesium oxide Alkali metals, alkaline earth metals, rare earth metals, or compounds thereof (such as acids, In addition to Lewis bases, tetrathiafulvalene (TTF), tetrathiaphtha Organic compounds such as nickelocene (abbreviation: TTN), nickelocene, and decamethylnickelocene are used. This can be done.

[0137] <Charge Generation Region> The charge generation region constituting the hole injection layer and the charge generation region 308 are made of a material having a high hole transporting property. This is a region that contains an acceptor material (electron acceptor). The acceptor material is a hole transport material. It is preferable that the weight ratio of the highly resistant substance is 0.1 to 4.0. It is.

[0138] In addition, the charge generation region contains a substance with high hole transport properties and a substance with acceptor properties in the same film. In addition to the case where a layer containing a substance with high hole transport properties and a layer containing a substance with high hole transport properties are stacked, However, when the charge generating region is provided on the cathode side, a layer having a high hole transporting property is required. In the case of a laminated structure in which the layer containing the substance is in contact with the cathode and the charge generation region is provided on the anode side In the case of the second type, the layer containing the acceptor material is in contact with the anode.

[0139] As a material having a high hole transporting property, an organic compound having a higher hole transporting property than an electron transporting property may be used. , especially, 10 -6 cm 2 It is preferable that the organic compound has a hole mobility of .beta. / Vs or more. stomach.

[0140] Specifically, the compound represented by the above general formula (G0) and aromatic compounds such as NPB and BPAFLP are Aromatic amine compounds, carbazole derivatives such as CBP, CzPA, and PCzPA, t-BuDN Aromatic hydrocarbon compounds such as A, DNA, DPAnth, etc., and polymerization of PVK, PVTPA, etc. The hole transporting layer 302 may be formed of a material having a high hole transporting property, such as a compound. Substances can be used.

[0141] Acceptor substances include 7,7,8,8-tetracyano-2,3,5,6-tetracyano. Fluoroquinodimethane (abbreviation: F 4 -TCNQ), halogen compounds such as chloranil, pyridine Dino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile (abbreviation: PPDN), dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7 ,10,11-hexacarbonitrile (abbreviation: HAT-CN), and other cyano compounds, transition metals Examples of the oxides of metals include oxides of metals belonging to groups 4 to 8 in the periodic table. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, Butene, tungsten oxide, manganese oxide, and rhenium oxide are preferred because of their high electron accepting properties. In particular, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. I wish.

[0142] <Electron injection buffer layer 306> The electron injection buffer layer 306 is a layer containing a material with high electron injection properties. The charge generating layer 306 facilitates the injection of electrons from the charge generating region 308 into the EL layer 203. The above-mentioned materials can be used as the material with high electron injection properties. The electron transport layer 306 may contain the above-mentioned substance having high electron transport properties and a donor substance.

[0143] <Electronic Relay Layer 307> In the electron relay layer 307, the acceptor material is extracted in the charge generation region 308. Accepts electrons quickly.

[0144] The electron-relay layer 307 contains a substance having a high electron-transporting property. Using phthalocyanine-based materials or metal complexes with metal-oxygen bonds and aromatic ligands is preferred.

[0145] Specific examples of the phthalocyanine-based material include CuPc and SnPc (Phthalocyanine anine tin(II) complex), ZnPc(Phthalocyani ne zinc complex), CoPc(Cobalt(II)phthaloc yanine, β-form), FePc (Phthalocyanine Iron ), PhO-VOPc(Vanadyl 2,9,16,23-tetraphenox y-29H,31H-phthalocyanine) etc.

[0146] The metal complex having a metal-oxygen bond and an aromatic ligand is preferably a metal complex having a metal-oxygen double bond. It is preferable to use a metal complex in which the metal-oxygen double bond has acceptor properties. This makes it easier for electrons to move (become)

[0147] In addition, as the metal complex having the metal-oxygen bond and the aromatic ligand, a phthalocyanine-based material Materials are preferred. In particular, VOPc (vanadyl phthalocyanine), S nOPc(Phthalocyanine tin(IV) oxide comple x), TiOPc(Phthalocyanine titanium oxide c Complexes are structures in which the metal-oxygen double bond is easily reactive with other molecules. , is preferred because of its high acceptor properties.

[0148] The phthalocyanine-based material is preferably one having a phenoxy group, specifically, P Phthalocyanine derivatives having a phenoxy group, such as hO-VOPc, are preferred. The phthalocyanine derivative having an oxy group is soluble in a solvent, and therefore can be used to form a light-emitting element. The method has the advantage that it is easy to handle and easy to maintain the equipment used for film formation. do.

[0149] Other examples of materials with high electron transport properties include 3,4,9,10-perylenetetrate. Tetracarboxylic dianhydride (abbreviation: PTCDA), 3,4,9,10-perylenetetracarbo Xylic bisbenzimidazole (abbreviation: PTCBI), N,N'-dioctyl-3, 4,9,10-perylenetetracarboxylic diimide (abbreviation: PTCDI-CH), N, N'-Dihexyl-3,4,9,10-perylenetetracarboxylic diimide (abbreviation: He x PTC) and other perylene derivatives, Phosphorus-2,3-dicarbonitrile (PPDN), 2,3,6,7,10,11-hexafluorophenyl Hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT(C N) 6 ), 2,3-diphenylpyrido[2,3-b]pyrazine (abbreviation: 2PYPR), 2 ,3-Bis(4-fluorophenyl)pyrido[2,3-b]pyrazine (abbreviation: F2PYP Nitrogen-containing condensed aromatic compounds such as benzene, benzene- ... Therefore, it is preferable as the material used to form the electron relay layer 307.

[0150] In addition, 7,7,8,8-tetracyanoquinodimethane (TCNQ), 1,4,5,8 -Naphthalenetetracarboxylic dianhydride (NTCDA), Perfluoropentacene , copper hexadecafluorophthalocyanine (abbreviation: F 16 CuPc), N,N'-bis(2 ,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctyl ethyl)-1,4,5,8-naphthalenetetracarboxylic diimide (abbreviation: NTCDI-C 8F), 3',4'-dibutyl-5,5''-bis(dicyanomethylene)-5,5''- Dihydro-2,2':5',2''-terthiophene (abbreviation: DCMT), methanofulva phenylene (e.g., [6,6]-phenylC 61 Butyric acid methyl ester, etc. can be used. do.

[0151] The electron relay layer 307 may further include the donor material described above. By incorporating a donor substance into 07, electrons can be easily transferred, making the light-emitting element more It becomes possible to operate the device at a low voltage.

[0152] The LUMO level of the material with high electron transport properties or the donor material is included in the charge generation region 308. The LUMO level of the acceptor material to be used and the electron transporting material having high electron transport properties contained in the electron transport layer 304 are The LUMO level of the material (or the electron relay layer 307) is The LUMO level is between -5 and the LUMO level of the adjacent EL layer 203. It is preferable that the electron relay layer 307 has a donor potential of -3.0 eV or more. In the case where a conductive material is contained, the alumina contained in the charge generation region 308 is used as a material having high electron transport properties. It is possible to use a substance that has a LUMO level higher than the acceptor level of the acceptor material. can.

[0153] The layers constituting the EL layer 203 and the intermediate layer 207 are formed by deposition (vacuum deposition). It can be formed by methods such as deposition method, transfer method, printing method, inkjet method, coating method, etc. can.

[0154] Using the light-emitting element described in this embodiment mode, a passive matrix light-emitting device or a transistor An active matrix type light emitting device in which the driving of the light emitting element is controlled by a stator is manufactured. The light emitting device can be applied to electronic devices, lighting devices, and the like.

[0155] This embodiment mode can be freely combined with other embodiment modes.

[0156] (Embodiment 2) In this embodiment, a light-emitting element of one embodiment of the present invention will be described with reference to FIG.

[0157] The light-emitting element shown in FIG. 2A includes an EL layer 20 between a first electrode 201 and a second electrode 205. The EL layer 203 includes a light-emitting layer 213.

[0158] The light-emitting element shown in FIG. 2A includes a light-emitting layer 213 and a first organic compound 221 and a second organic compound 222. The first organic compound 221 includes the compound 222 and the phosphorescent compound 223. The first organic compound 221 is a compound represented by the general formula (G0) shown in FIG. 1, and the molecular weight of the first organic compound 221 is 50 0 or more and 2000 or less, and the second organic compound 222 is a compound having an electron transporting property. .

[0159] The phosphorescent compound 223 is a guest material in the light-emitting layer 213. The ratio of the first organic compound 221 and the second organic compound 222 contained in the light-emitting layer 213 The material having a larger amount is used as the host material in the light-emitting layer 213 .

[0160] The triplet excitation energies of the first organic compound 221 and the second organic compound 222 are Level of Energy (T 1 The T level of the phosphorescent compound 223 1 It is preferable that the level is higher than The T of the first organic compound 221 (or the second organic compound 222) 1 Level phosphorescent compound 2 23 T 1 If the triplet excitation energy of the phosphorescent compound 223 that contributes to the emission is lower than the The first organic compound 221 (or the second organic compound 222) quenches the This is because it leads to a decrease in luminous efficiency.

[0161] To increase the efficiency of energy transfer from the host material to the guest material, The Förster mechanism (dipole-dipole interaction) and the Dexter mechanism (electron Considering the exchange interaction, the emission spectrum of the host molecule (energy from the singlet excited state) When discussing energy transfer, consider the fluorescence spectrum and energy transfer from triplet excited states. The phosphorescence spectrum (if the guest molecule is phosphorescent) and the absorption spectrum (more specifically, the longest wavelength ( It is preferable that the overlap with the spectrum in the absorption band on the low energy side is large. .

[0162] However, when a phosphorescent compound is used as a guest material, the fluorescence spectrum of the host material The absorption spectrum of the longest wavelength (lowest energy) absorption band of the guest material is overlapped with that of the It is difficult to achieve this because doing so would affect the phosphorescence spectrum of the host material. Since the T is located on the longer wavelength (lower energy) side of the fluorescence spectrum, 1 The level is T of the phosphorescent compound 1 This causes the quenching problem described above. On the other hand, to avoid the quenching problem, the T 1 Rank is guest The phosphorescent compound used as the material 1 If we design it so that it exceeds the level, then the host material The fluorescence spectrum of is shifted to the short wavelength (high energy) side, so that The absorption spectrum does not overlap with the absorption band of the guest material on the longest wavelength (lowest energy) side. Therefore, the fluorescence spectrum of the host material is adjusted to the longest wavelength (low energy) of the guest material. The absorption spectrum of the singlet excited state of the host material was superimposed on that of the absorption band on the 1000 nm side. Maximizing energy transfer is usually difficult.

[0163] Therefore, in this embodiment, the first organic compound 221 and the second organic compound 222 are excited The combination forms a complex.

[0164] The exciplex will be explained with reference to FIGS. 2(B) and (C).

[0165] FIG. 2B is a schematic diagram showing the concept of an exciplex. The fluorescence spectrum of the first organic compound 221 (or the second organic compound 222) The phosphorescence spectrum of the phosphorescent compound 222, the absorption spectrum of the phosphorescent compound 223, and the emission spectrum of the exciplex Represents the light spectrum.

[0166] For example, in the light-emitting layer 213, the fluorescence spectrum of the first organic compound 221 and the fluorescence spectrum of the second organic compound 222 are The fluorescence spectrum of the organic compound 222 is closer to the emission spectrum of the exciplex at longer wavelengths. The emission spectrum of the exciplex and the phosphorescent compound 223 (guest material) The first organic compound 221 and the second organic compound 222 are mixed so that the absorption spectrum of the first organic compound 221 overlaps with the absorption spectrum of the second organic compound 222. The selection of compound 222 maximizes the energy transfer from the singlet excited state. (Figure 2(B)).

[0167] Regarding the triplet excited state, the energy transfer occurs not from the host material but from the exciplex. It is believed that this will occur.

[0168] Therefore, the emission wavelength of the formed exciplex is determined by the first organic compound 221 and the second organic compound 222. Since the emission wavelengths (fluorescence wavelengths) of the compounds 222 and 23 exist on the longer wavelength side, , the fluorescence spectrum of the first organic compound 221 and the fluorescence spectrum of the second organic compound 222 can be an emission spectrum located on the longer wavelength side.

[0169] Furthermore, the difference between the singlet excitation energy and the triplet excitation energy of an exciplex is extremely small. In other words, the emission spectrum from the singlet state of the exciplex and the emission spectrum from the triplet state The emission spectra of the exciplexes are very close to each other. The emission spectrum of the phosphorescent compound (generally the emission spectrum from the singlet state of the exciplex) is When designed to overlap with the absorption band located at the longest wavelength side of compound 223 (guest material) Emission spectrum from the triplet state of the exciplex (not observed at room temperature, but also at low temperatures) The longest wavelength absorption of the phosphorescent compound 223 (guest material) is also observed. In other words, not only the energy transfer from the singlet excited state, but also the energy transfer from the triplet excited state The efficiency of energy transfer from the singlet excited state is also increased, resulting in efficient transfer of both singlet and triplet states. It is possible to emit light efficiently.

[0170] In this manner, in the light-emitting element of one embodiment of the present invention, the exciplex formed in the light-emitting layer 213 Taking advantage of the overlap between the emission spectrum and the absorption spectrum of the phosphorescent compound 223 (guest material), Since energy is transferred using this method, the energy transfer efficiency is high.

[0171] In addition, since exciplexes exist only in excited states, there is no ground state that can absorb energy. Therefore, the singlet excited state and triplet excited state of the phosphorescent compound 223 (guest material) Phosphorescent compound 223 (guest material) emits light by energy transfer from the excited state to the exciplex. In principle, the phenomenon of deactivation before the photocatalytic activity (i.e., loss of luminescence efficiency) does not occur. can be done.

[0172] The above-mentioned exciplexes are formed by interactions between different molecules in an excited state. In addition, exciplexes are made up of materials with relatively low LUMO levels and materials with high HOMO levels. st Occupied Molecular Orbital It is generally known that it is easy to form between materials having the same structure.

[0173] Here, the energies of the first organic compound 221, the second organic compound 222, and the exciplex are The concept of the level will be explained with reference to FIG. 2(C). The energy levels of the compound 221, the second organic compound 222, and the exciplex are shown diagrammatically. This is the diagram.

[0174] The HOMO level and the LUMO level of the first organic compound 221 and the second organic compound 222 are Specifically, the HOMO level of the second organic compound 222 is lower than that of the first organic compound 222. HOMO level of compound 221 < LUMO level of second organic compound 222 < LUMO level of first organic compound The energy levels of these two organic compounds differ in the order of LUMO level 221. When an exciplex is formed by the second organic compound 22, the LUMO level of the exciplex is 2, and the HOMO level is derived from the first organic compound 221 (see FIG. 2C).

[0175] The emission wavelength of an exciplex also depends on the energy difference between the HOMO and LUMO levels. Generally speaking, the larger the energy difference, the shorter the emission wavelength. The smaller the size, the longer the emission wavelength.

[0176] Therefore, the energy difference of the exciplex is the energy difference of the first organic compound 221, and The energy difference between the first organic compound 222 and the second organic compound 223 is smaller than that between the first organic compound 222 and the second organic compound 223. The emission wavelength of the exciplex is longer than that of the second organic compound 222 and the first organic compound 21. It becomes wavelength.

[0177] In addition, the formation process of the exciplex in one embodiment of the present invention can be carried out in the following two ways: .

[0178] The first exciplex formation process is when a first organic compound 221 and a second organic compound 222 react with each other. This is the process of forming an exciplex from a carrier-containing state (cation or anion). do.

[0179] In general, when electrons and holes recombine in a host material, they are released from the host material in an excited state. The excitation energy is transferred to the guest material, which then reaches an excited state and emits light. The host material itself emits light before the excitation energy is transferred from the host material to the guest material. In the case of , the excitation energy becomes thermal energy, and a part of the excitation energy is deactivated. .

[0180] However, in one embodiment of the present invention, the first organic compound 221 and the second organic compound 22 Since 2 forms an exciplex from a state with a carrier (cation or anion), 1 The formation of singlet excitons in the first organic compound 221 and the second organic compound 222 can be suppressed. In other words, there exists a process in which an exciplex is formed directly without forming a singlet exciton. This can also suppress the deactivation of the singlet excitation energy. This makes it possible to realize a light emitting element with a long life.

[0181] For example, the first organic compound 221 is a material having a hole transporting property that transports holes (carriers). It is a hole-trapping compound that has a high HOMO level and is easy to capture holes. The organic compound 222 of the second embodiment is one of the materials having electron transport properties that easily captures electrons (carriers). In the case of a compound having a low LUMO level and an electron trapping property, The cation of the first organic compound 221 and the anion of the second organic compound 222 are directly exciplexed. The exciplex formed in this process is called an electrochemical complex. We will call it the electroplex.

[0182] In this way, the singlet excited states of the first organic compound 221 and the second organic compound 222 are The generation of electrons is suppressed, and the energy is transferred from the electroplex to the phosphorescent compound 223 (guest material). By performing the electron transfer, a light-emitting element with high light-emitting efficiency can be obtained. The occurrence of the triplet excited state of the organic compound 221 and the second organic compound 222 is also suppressed. Since the exciplex is directly formed, the exciplex is excited into the phosphorescent compound 223 (guest material). It is thought that energy is transferred.

[0183] The formation process of the second exciplex is as follows: A molecule that forms a singlet exciton and then interacts with the other molecule in the ground state to form an exciplex. Unlike electroplexing, in this case, the first organic compound 22 A singlet excited state of the first or second organic compound 222 is generated, but this is quickly excited. Since the singlet excited state is converted into an excited complex, the deactivation of the singlet excited energy and the deactivation of the singlet excited state occur. This can suppress the reaction of the first organic compound 221 or the second organic compound 222. The compound 222 can be prevented from losing excitation energy, and thus a light-emitting element having a long life can be obtained. In this case, the first organic compound 221 or the second organic compound 222 Similarly, the triplet excited state was rapidly converted to an exciplex, and the exciplex was converted to a phosphorescent compound 22. It is believed that energy is transferred to 3 (guest material).

[0184] The first organic compound 221 is a compound with hole trapping properties, and the second organic compound 22 2 is an electron trapping compound, and the difference between the HOMO level and the LUMO level of these compounds When the potential difference is large (specifically, the difference is 0.3 eV or more), the holes are selectively transported to the first organic compound. The electrons selectively enter the second organic compound 222. In this case, the singlet excited The process of forming an electroplex is more favorable than the process of forming an exciplex via a molecule. is considered to be given priority.

[0185] Generally, the singlet or triplet excited state of the host material is converted into a phosphorescent compound. On the other hand, in one embodiment of the present invention, the energy transfer between the host material and another material is taken into consideration. This method differs from conventional methods in that it first forms an exciplex with the nucleon and then uses energy transfer from the exciplex. This difference is what makes it possible to achieve unprecedentedly high luminous efficiency. It is.

[0186] Generally, when an exciplex is used in the light-emitting layer of a light-emitting device, it is possible to control the color of emitted light. Although they are valuable, the luminescence efficiency is usually significantly reduced. It has been believed that such a light-emitting device is not suitable for achieving a highly efficient light-emitting device. However, as shown in one embodiment of the present invention, by using an exciplex as a medium for energy transfer, On the other hand, it is possible to maximize the luminous efficiency. This is a technology that contradicts the conventional concept. It is a technical idea.

[0187] The emission spectrum of the exciplex and the absorption spectrum of phosphorescent compound 223 (guest material) In order to overlap sufficiently, the energy values ​​of the peaks in the emission spectrum and the absorption spectrum must be The difference in energy from the lowest energy absorption band peak is within 0.3 eV It is preferable that the difference is within 0.2 eV, and more preferable that the difference is within 0.1 eV. be.

[0188] In the light-emitting element of one embodiment of the present invention, the excitation energy of the exciplex is 23 (guest material), and practically no emission from the exciplex was observed. Therefore, it is preferable that the phosphorescent compound 223 (guest material) is not generated via an exciplex. Preferably, the phosphorescent compound 223 emits phosphorescence by transferring energy to the phosphorescent compound 223 .

[0189] In addition, when a phosphorescent compound is used as a host material in the light-emitting element of one embodiment of the present invention, the In this case, the host material itself becomes more likely to emit light, and energy is less likely to be transferred to the guest material. In this case, it is sufficient if the phosphorescent compound used in the host material emits light efficiently. Due to the problem of quenching, it is difficult to achieve high luminous efficiency. At least one of the first organic compound 221 and the second organic compound 222 is a fluorescent compound (i.e., In other words, compounds that are prone to luminescence or thermal deactivation from the singlet excited state are effective. Therefore, at least one of the first organic compound 221 and the second organic compound 222 It is preferably a fluorescent compound.

[0190] As described above, the light-emitting element described in this embodiment has an emission spectrum of an exciplex and a phosphorescence Energy transfer using the overlap of the absorption spectrum with the guest compound This allows for the realization of a light-emitting element with high luminous efficiency. Cut.

[0191] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. It is possible.

[0192] (Embodiment 3) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described with reference to FIG. 3B is a plan view of a light-emitting device according to one embodiment of the present invention, and FIG. FIG. 2 is a cross-sectional view taken along dashed line AB.

[0193] The light emitting device of this embodiment is surrounded by a supporting substrate 401, a sealing substrate 405, and a sealing material 407. In the space 415, a light-emitting element 403 (a first electrode 421, an EL layer 423, and a second electrode 4 The light emitting element 403 has a bottom emission structure, specifically, A first electrode 421 that transmits visible light is provided on a substrate 401. An EL layer A second electrode 425 that reflects visible light is provided on the EL layer 423 .

[0194] The light-emitting element 403 in this embodiment is a light-emitting element according to one embodiment of the present invention. The light-emitting element of one embodiment has a long lifetime, and therefore a highly reliable light-emitting device can be realized. The light-emitting element of one embodiment of the present invention exhibits high emission efficiency in a high luminance region. Optical devices can be realized.

[0195] The first terminal 409a is electrically connected to the auxiliary wiring 417 and the first electrode 421. An insulating layer 419 is provided on the electrode 421 in a region overlapping with the auxiliary wiring 417 . The first terminal 409a and the second electrode 425 are electrically insulated by an insulating layer 419. The second terminal 409b is electrically connected to the second electrode 425. 4 shows a configuration in which the first electrode 421 is formed on the auxiliary wiring 417. An auxiliary wiring 417 may be formed on the wiring 421 .

[0196] In addition, since organic EL elements emit light in an area with a higher refractive index than the atmosphere, the light is extracted into the atmosphere. When the organic EL element is heated, there are conditions that cause total reflection within the organic EL element or at the boundary between the organic EL element and the atmosphere. Therefore, there is a problem that the light extraction efficiency of the organic EL element is less than 100%.

[0197] Therefore, for example, a light extraction structure 411a is provided at the interface between the support substrate 401 and the atmosphere. It is preferable that the refractive index of the support substrate 401 is larger than that of the air. By providing a light extraction structure 411a at the interface of the support substrate 401, the light emitted from the support substrate 401 is prevented from being released into the atmosphere due to total reflection. The amount of light that cannot be extracted can be reduced, and the light extraction efficiency of the light emitting device can be improved.

[0198] In addition, the light-extraction structure 411b is provided at the interface between the light-emitting element 403 and the support substrate 401. is preferred.

[0199] However, if the first electrode 421 has unevenness, the EL layer 4 formed on the first electrode 421 may be damaged. Therefore, in this embodiment, a leakage current may occur in the EL layer 4. A planarization layer 413 having a refractive index equal to or greater than 23 is disposed in contact with the light extraction structure 411b. This allows the first electrode 421 to be a flat film, and the EL layer 423 This can suppress the occurrence of leakage current caused by the unevenness of the first electrode 421. In addition, since the light extraction structure 411b is provided at the interface between the planarization layer 413 and the support substrate 401, This reduces the amount of light that cannot be extracted to the atmosphere due to total reflection, and improves the light extraction efficiency of light-emitting devices. It is possible to do so.

[0200] In FIG. 3B, the support substrate 401, the light extraction structure 411a, and the light extraction structure Although structure 411b is shown as a separate element, the present invention is not limited to this. Alternatively, all of them may be formed integrally. The first electrode 421 does not have unevenness (for example, the light extraction structure 411b does not have unevenness). In such a case, the planarizing layer 413 may not be provided.

[0201] Although the light emitting device shown in FIG. 3A has an octagonal shape, the present invention is not limited to this. The light emitting device may have other polygonal or curved shapes. The shape of the slits is preferably a triangle, a square, a regular hexagon, etc., because it is difficult to fit multiple slits in a limited area. This is because the light emitting device can be mounted without gaps. This is because the light emitting device can be formed by using the same. It is also possible to have a plurality of light emitting elements.

[0202] The shape of the projections and recesses of the light extraction structure 411a and the light extraction structure 411b is determined by the following regularity: If the shape of the unevenness is periodic, the unevenness may rotate depending on the size of the unevenness. By acting like a grating, the interference effect is strengthened, and light of specific wavelengths is extracted into the atmosphere. Therefore, it is preferable that the shape of the projections and recesses does not have periodicity. .

[0203] The shape of the bottom surface of the unevenness is not particularly limited, and may be, for example, a polygon such as a triangle or a rectangle, or a circle. When the bottom shape of the unevenness has regularity, there is a gap between adjacent parts. For example, a preferred bottom shape is a regular hexagon. Examples include rectangular shapes.

[0204] The shape of the projections and recesses is not particularly limited, and may be, for example, a hemisphere, a cone, a pyramid (a triangular pyramid, a square pyramid, etc.), It may be in the shape of an umbrella or the like having an apex.

[0205] When the size and height of the unevenness are 1 μm or more, the effect of light interference can be suppressed. This is preferable because it is possible to

[0206] The light extraction structure 411a and the light extraction structure 411b are directly fabricated on the support substrate 401. The method can be, for example, an etching method, an abrasive processing method (sand blasting), etc. method), microblasting method, frosting method, droplet ejection method, printing method (screen printing (methods where patterns are formed, such as printing and offset printing), coating methods such as spin coating, and dip coating. The printing method, dispenser method, imprint method, nanoimprint method, etc. can be used appropriately. can.

[0207] The light extraction structure 411a and the light extraction structure 411b are made of a material such as resin. In addition, the light extraction structure 411a and the light extraction structure 411b may be Hemispherical lenses, microlens arrays, films with uneven structures, light diffusion films, etc. For example, the lens or film may be mounted on a support substrate 401. 401 or the lens or film is bonded using an adhesive having a refractive index similar to that of the lens or film. By this, the light extraction structure 411a and the light extraction structure 411b can be formed. .

[0208] The planarization layer 413 has a surface in contact with the first electrode 421 rather than a surface in contact with the light extraction structure 411b. Therefore, the first electrode 421 can be a flat film. As a result, leakage current in the EL layer 423 caused by the unevenness of the first electrode 421 can be suppressed. The planarization layer 413 may be made of a material having a high refractive index, such as glass or resin. The planarization layer 413 has a light-transmitting property.

[0209] This embodiment mode can be combined with other embodiment modes as appropriate.

[0210] (Embodiment 4) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described with reference to FIG. 4B is a plan view of a light-emitting device according to one embodiment of the present invention, and FIG. FIG. 2 is a cross-sectional view taken along dashed line CD.

[0211] The active matrix light emitting device according to this embodiment has a light emitting section on a support substrate 501. 551, a drive circuit section 552 (a gate side drive circuit section), a drive circuit section 553 (a source side drive circuit section), The light emitting section 551 and the driving circuit sections 552 and 553 are supported by a support member 506. The substrate 501 is sealed in a space 515 formed by the sealing substrate 505 and the sealing material 507. .

[0212] The light-emitting section 551 shown in FIG. 4B includes a switching transistor 541a and a current control A transistor 541b for the transistor 541b and a wiring (source electrode or drain electrode) of the transistor 541b The light emitting unit is formed by a plurality of light emitting units each including a first electrode 521 and a second electrode 525 electrically connected to the first electrode 521. is.

[0213] The light emitting element 503 has a top emission structure and includes a first electrode 521 that transmits visible light. The first electrode 522 is made up of a first electrode 523 and a second electrode 525 that reflects visible light. A partition wall 519 is formed to cover the end of the second electrode 525 .

[0214] The light-emitting element 503 in this embodiment is a light-emitting element according to one embodiment of the present invention. The light-emitting element of one embodiment has a long lifetime, and therefore a highly reliable light-emitting device can be realized. The light-emitting element of one embodiment of the present invention exhibits high emission efficiency in a high luminance region. Optical devices can be realized.

[0215] On the support substrate 501, external signals (video signals, clock signals, etc.) are input to the driving circuit sections 552 and 553. Connect the external input terminal that transmits the following signals: In this embodiment, an FPC 509 is used as an external input terminal. This shows an example where a flexible printed circuit (Flexible Printed Circuit) is provided. A printed wiring board (PWB) may be attached to the FPC 509. The light emitting device in this case is not only the light emitting device body, but also the light emitting device body to which the FPC or PWB is attached. This also includes items with the sticker attached.

[0216] The driver circuit portions 552 and 553 each include a plurality of transistors. 552 includes an n-channel transistor 542 and a p-channel transistor 543. The driver circuit section has a combination of various CMOS circuits. The transistor can be formed of an S circuit, a PMOS circuit, or an NMOS circuit. shows a driver-integrated type in which a driving circuit is formed on a substrate on which a light-emitting part is formed, The present invention is not limited to this configuration, and the driving circuit may be provided on a substrate separate from the substrate on which the light emitting portion is formed. It is also possible to form a path.

[0217] In order to prevent an increase in the number of steps, the lead-out wiring 517 is formed by connecting electrodes and wiring used in the light-emitting section and the driving circuit section. It is preferable to manufacture the wire using the same material and in the same process.

[0218] In this embodiment, the lead wiring 517 is provided in the light emitting section 551 and the driving circuit section 552. The source and drain electrodes of the transistor are fabricated using the same material and process. show.

[0219] In FIG. 4B, the sealing material 507 is in contact with the first insulating layer 511 on the lead wiring 517. The sealing material 507 may have low adhesion to metal. It is preferable that the insulating film 514 contacts the inorganic insulating film provided on the lead-out wiring 517. By adopting this configuration, it is possible to realize a light emitting device having high sealing and adhesion properties and high reliability. Inorganic insulating films include oxide films of metals and semiconductors, nitride films of metals and semiconductors, and Examples of the semiconductor oxynitride film include a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. Examples of the insulating film include a silicon oxide film, a silicon nitride film, an aluminum oxide film, and a titanium oxide film. .

[0220] The first insulating layer 511 is formed to suppress the diffusion of impurities into the semiconductor that constitutes the transistor. In addition, the second insulating layer 513 reduces surface irregularities caused by the transistor. Therefore, it is preferable to select an insulating film having a planarizing function.

[0221] There is no particular limitation on the structure of a transistor used in a light-emitting device according to one embodiment of the present invention. A bottom-gate transistor such as an inverted staggered type may be used. Also, a channel etch type or a channel protection type may be used. There is no particular limitation on the material used for the resistor.

[0222] The semiconductor layer can be formed using silicon or an oxide semiconductor. , single crystal silicon, polycrystalline silicon, etc., and oxide semiconductors include In-Ga-Z As the semiconductor layer, an In-Ga-Zn system By using an oxide semiconductor, which is a metal oxide, to create a transistor with low off-state current, light emission This is preferable because it can suppress leakage current when the element is turned off.

[0223] The sealing substrate 505 has a color layer, which is a colored layer, at a position overlapping the light emitting element 503 (the light emitting region of the light emitting element 503). The color filter 533 is provided to filter the light emitted from the light emitting element 503. For example, a full-color display can be created by using white-emitting light-emitting elements. When used as a display device, multiple light-emitting units with different color filters are used. In that case, you can use three colors: red (R), green (G), and blue (B), or you can add yellow to these. It can also be made into four colors by adding (Y).

[0224] In addition, a black matrix is ​​provided between adjacent color filters 533 (at positions overlapping with the partition walls 519). The black matrix 531 is provided to prevent the light from being emitted by the adjacent light-emitting units. The light from the optical element 503 is blocked, and color mixing between adjacent light emitting units is suppressed. The end of the color filter 533 is arranged to overlap with the black matrix 531. As a result, light leakage can be suppressed. A material that blocks light emitted from 3 can be used, and is formed using materials such as metal and resin. The black matrix 531 can be used to light-emitting parts such as the driving circuit part 552. It may be provided in an area other than 551.

[0225] In addition, an overcoat layer 53 covering the color filter 533 and the black matrix 531 The overcoat layer 535 transmits light emitted from the light emitting element 503. The insulating film is made of a material such as an inorganic insulating film or an organic insulating film. If the overcoat layer 535 is unnecessary, it may not be provided.

[0226] In the present embodiment, the light emitting device using the color filter method has been described as an example. The light configuration is not limited to this, and for example, a color-coded method or a color conversion method may be applied.

[0227] This embodiment mode can be combined with other embodiment modes as appropriate.

[0228] (Embodiment 5) In this embodiment, a light-emitting device according to one embodiment of the present invention is used for an electronic device and a lighting device. An example will be described with reference to FIGS.

[0229] The electronic device of this embodiment includes a light-emitting device according to one embodiment of the present invention in a display portion. The lighting device of the embodiment includes the light-emitting device according to one aspect of the present invention in a light-emitting section (lighting section). By applying the light-emitting device of one embodiment, a highly reliable electronic device and a highly reliable lighting device can be provided. In addition, by using the light-emitting device of one embodiment of the present invention, electronic devices and and lighting devices can be provided.

[0230] As an example of an electronic device to which a light-emitting device is applied, a television set (television or television (also called television receivers), computer monitors, digital cameras, digital video Cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), mobile phones These include portable game machines, mobile information terminals, audio playback devices, and large game machines such as pachinko machines. Specific examples of these electronic devices and lighting devices are shown in Figs.

[0231] FIG. 5A shows an example of a television device. A television device 7100 includes a housing. A display unit 7102 is built into the body 7101. The display unit 7102 displays images. The light-emitting device to which one embodiment of the present invention is applied can be used for the display portion 7102. In addition, a configuration in which the housing 7101 is supported by a stand 7103 is shown here. is.

[0232] The television device 7100 can be operated using an operation switch provided on the housing 7101 or a separate remote control. This can be done by the remote control operation device 7111. This allows you to control the channel and volume, and the image displayed on the display unit 7102 In addition, the remote control operation device 7111 can be operated. A display unit for displaying information output from the

[0233] The television device 7100 includes a receiver and a modem. It is possible to receive more general television broadcasts, and furthermore, to receive them by wire or wirelessly via a modem. By connecting to a communication network, It is also possible to communicate information between followers and recipients, or between recipients themselves.

[0234] FIG. 5B shows an example of a computer. The computer 7200 includes a main body 720 1, a housing 7202, a display unit 7203, a keyboard 7204, an external connection port 7205, The computer includes an imaging device 7206 and the like. The device is used for the display portion 7203 .

[0235] FIG. 5C shows an example of a portable game machine. The portable game machine 7300 has a housing 7 The device is composed of two housings, housing 7301a and housing 7301b, and is connected by a connecting part 7302. The display unit 7303a is incorporated in the housing 7301a, and the housing 73 The display unit 7303b is incorporated in the portable game device 01b. The device includes a speaker section 7304, a recording medium insertion section 7305, operation keys 7306, and a connection terminal 73 07, Sensor 7308 (force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid , magnetic, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, (including functions to measure humidity, gradient, vibration, odor or infrared rays), LED lamp, Of course, the configuration of the portable game machine is not limited to the above. At least one of the display portion 7303a and the display portion 7303b may include a display device according to one embodiment of the present invention. It is sufficient to use a light emitting device, and other auxiliary equipment may be appropriately provided. The portable game machine shown in FIG. 5C is a game machine that uses a program or data recorded on a recording medium. It also has the function of reading the information and displaying it on the display, as well as wirelessly communicating with other portable game consoles to share information. The functions of the portable game machine shown in FIG. 5(C) are not limited to these. It can have a variety of functions.

[0236] FIG. 5D shows an example of a mobile phone. A mobile phone 7400 is attached to a housing 7401. In addition to the built-in display unit 7402, operation buttons 7403, external connection port 7404, The mobile phone 7400 includes a speaker 7405, a microphone 7406, and the like. The light-emitting device of one embodiment of the above is used for the display portion 7402 .

[0237] In a mobile phone 7400 shown in FIG. 5D, information is displayed by touching a display portion 7402 with a finger or the like. You can also make a call or write an email by This can be done by touching the display portion 7402 with a finger or the like.

[0238] The screen of the display unit 7402 has three main modes. The first is a display mode that is mainly used for displaying images. The first mode is a display mode, the second is an input mode for inputting information such as characters, and the third mode is a display mode. This is a display + input mode that combines the display mode and the input mode.

[0239] For example, when making a call or composing an e-mail, the display unit 7402 is used to input characters. This is the main character input mode, and the input operation of characters displayed on the screen can be performed.

[0240] In addition, the mobile phone 7400 includes a sensor for detecting tilt, such as a gyro sensor and an acceleration sensor. By providing a detection device having a sensor, the orientation of the mobile phone 7400 (portrait or landscape) can be determined. In this way, the screen display on the display portion 7402 can be automatically switched.

[0241] The screen mode can be changed by touching the display portion 7402 or by operating the housing 7401. This is done by operating the button 7403. Also, depending on the type of image displayed on the display unit 7402, For example, the image signal to be displayed on the display unit is a moving image. If it is data, the mode is switched to display mode, and if it is text data, the mode is switched to input mode.

[0242] In the input mode, the optical sensor of the display unit 7402 detects a signal and displays If there is no input by touch operation of the part 7402 for a certain period of time, the screen mode is changed to the input mode. Alternatively, the display mode may be switched from the normal mode to the display mode.

[0243] The display portion 7402 can also function as an image sensor. By touching the palm or fingers of the user on the sensor 02 and capturing an image of the palm print or fingerprint, the user can be authenticated. In addition, a backlight that emits near-infrared light to the display unit or a sensing light source that emits near-infrared light By using this, it is possible to image finger veins, palm veins, etc.

[0244] FIG. 5(E) shows an example of a foldable tablet terminal (in an open state). The tablet terminal 7500 includes a housing 7501a, a housing 7501b, a display unit 7502a, and a display The housing 7501a and the housing 7501b are connected by a shaft portion 7503. The housing 7501 can be opened and closed around the axis 7503. The a has a power supply 7504, operation keys 7505, a speaker 7506, etc. The portable terminal 7500 includes a light-emitting device according to one embodiment of the present invention in a display portion 7502a and a display portion 750 It is produced by using both or either of 2b.

[0245] At least a part of the display portion 7502a or the display portion 7502b is a touch panel area. By touching the displayed operation keys, data can be input. For example, The display unit 7502a is configured to display keyboard buttons on the entire surface thereof to function as a touch panel. 02b can be used as a display screen.

[0246] FIG. 6A shows a table lamp, which includes a lighting unit 7601, a shade 7602, an adjustable arm 7603, The table lamp includes a support 7604, a base 7605, and a power source 7606. The lighting fixture is manufactured by using such a light-emitting device in the lighting unit 7601. This includes fixed lighting fixtures and wall-mounted lighting fixtures.

[0247] FIG. 6B shows an example in which the light-emitting device of one embodiment of the present invention is used for an indoor lighting fixture 7701. The light-emitting device according to one embodiment of the present invention can be made large in area, and therefore can be used in a large-area lighting device. In addition, it can be used as a roll-type lighting fixture 7702. As shown in FIG. 6(B), a room equipped with an indoor lighting fixture 7701 is used. A table lamp 7703 may also be used in combination. EXAMPLES

[0248] In this example, a light-emitting element according to one embodiment of the present invention will be described with reference to FIG. The chemical formula of the material used is shown below:

[0249] [ka]

[0250] The methods for fabricating the light-emitting element 1 of this example, the comparative light-emitting element 2, and the comparative light-emitting element 3 are described below. .

[0251] (Light emitting element 1) First, indium tin oxide containing silicon oxide (ITSO) is deposited on a glass substrate 1100. The first electrode 1101 was formed by a deposition method. The thickness of the film was 110 nm. The electrode area was set to 2 mm×2 mm. Here, the first electrode 1101 was the positive electrode of the light-emitting element. It is an electrode that functions as a pole.

[0252] Next, as a pretreatment for forming a light emitting element on the glass substrate 1100, the substrate surface is washed with water. After washing and baking at 200°C for 1 hour, the substrate was subjected to UV ozone treatment for 370 seconds.

[0253] Then, 10 -4 The substrate is placed in a vacuum deposition apparatus whose inside has been reduced in pressure to about Pa, and vacuum deposition is performed. After vacuum baking at 170° C. for 30 minutes in the heating chamber of the device, the glass substrate 110 The mixture was allowed to cool for about 30 minutes.

[0254] Next, the surface on which the first electrode 1101 is formed is placed downward. The glass substrate 1100 thus formed was fixed to a substrate holder provided in a vacuum deposition apparatus, and then 10 -4 After the pressure was reduced to about Pa, a vapor deposition method using resistance heating was used to deposit a , 4,4',4''-(1,3,5-benzenetriyl)tri(dibenzothiophene) ( A hole injection layer 1 is formed by co-evaporating a thin film of SiO2 (DBT3P-II) and molybdenum (VI) oxide. The thickness of the film was 40 nm, and the ratio of DBT3P-II to molybdenum oxide was The ratio was adjusted to a weight ratio of 4:2 (=DBT3P-II:molybdenum oxide). The co-evaporation method is a method in which deposition is performed simultaneously from multiple evaporation sources in one processing chamber. do.

[0255] Next, 4-phenyl-4'-(9-phenylfluorene-9- A film of 20 nm thick phenyl)triphenylamine (abbreviation: BPAFLP) was formed. Then, a hole transport layer 1112 was formed.

[0256] In addition, 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo Zo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), N-(1,1'-biphenyl phenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(II I) (abbreviation: [Ir(dppm) 2 (acac)]) was co-evaporated onto the hole transport layer 1112. The light-emitting layer 1113 was formed on the substrate. and [Ir(dppm) 2The weight ratio of (acac) is 0.8:0.2:0.05 (=2m DBTBPDBq-II:PCBBiF:[Ir(dppm) 2 (acac)]) The thickness of the light-emitting layer 1113 was adjusted to 40 nm.

[0257] Next, 2mDBTBPDBq-II was formed on the light-emitting layer 1113 to a thickness of 15 nm. Furthermore, bathophenanthroline (abbreviation: BPhen) was formed into a film thickness of 15 nm. An electron transport layer 1114 was formed by depositing an electron transporting layer 1114 on the substrate.

[0258] Then, lithium fluoride (LiF) is evaporated onto the electron transport layer 1114 to a thickness of 1 nm. An electron injection layer 1115 was formed.

[0259] Finally, a 200 nm film of aluminum was deposited on the second electrode 1103, which served as the cathode. The light-emitting element 1 of this example was fabricated by depositing the material so as to have a thickness.

[0260] In the above-mentioned deposition process, the deposition was all performed by a resistance heating method.

[0261] (Comparative light-emitting element 2) The light-emitting layer 1113 of the comparative light-emitting element 2 was naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenyl PCBNBB), and [Ir(dppm) 2 (acac)] was co-evaporated. Here, 2mDBTBPDBq-II, PCBNBB and [Ir(dpp m) 2 The weight ratio of (acac)] was 0.8:0.2:0.05 (=2mDBTBPDBq -II:PCBNBB:[Ir(dppm) 2(acac)]). The thickness of the light-emitting layer 1113 was 40 nm. It was made in.

[0262] (Comparative light-emitting element 3) The light-emitting layer 1113 of the comparative light-emitting element 3 was made of 2mDBTBPDBq-II, N-[4-(9-furan phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-N-[4-( 1-naphthyl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBNBF), and and [Ir(dppm) 2 (acac)] was co-evaporated. TBPDBq-II, PCBNBF and [Ir(dppm) 2 (acac)] weight ratio is , 0.8:0.2:0.05(=2mDBTBPDBq-II:PCBNBF:[Ir( dppm) 2 The thickness of the light-emitting layer 1113 was adjusted to 4 The light-emitting element was fabricated in the same manner as in the light-emitting element 1 except for the light-emitting layer 1113.

[0263] The element structure of the light-emitting element of this example obtained as described above is shown in Table 1.

[0264] [Table 1]

[0265] The light-emitting element 1, the comparative light-emitting element 2, and the comparative light-emitting element 3 were placed in a glove box with a nitrogen atmosphere. In order to prevent each light-emitting element from being exposed to the atmosphere, the element was sealed with a glass substrate. After that, the operating characteristics of these light-emitting devices were measured. The measurements were performed at room temperature (25°C). The atmosphere was relaxed.

[0266] The luminance-current efficiency characteristics of the light-emitting element of this embodiment are shown in FIG. 8. In FIG. 8, the horizontal axis is the luminance (c d / m 2 ), and the vertical axis represents the current efficiency (cd / A). The voltage-luminance characteristics are shown in Figure 9. In Fig. 9, the horizontal axis is voltage (V) and the vertical axis is luminance (cd / m 2 ) and also represents the luminance-external The quantum efficiency characteristics are shown in FIG. 10. In FIG. 10, the horizontal axis represents luminance (cd / m 2 ) and the vertical axis is , the external quantum efficiency (%). Also, the luminance of each light-emitting element is 1000 cd / m 2 Nearby Voltage (V) and current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), current efficiency ( The emission efficiency (cd / A), power efficiency (lm / W), and external quantum efficiency (%) are shown in Table 2.

[0267] [Table 2]

[0268] As shown in Table 2, 1200cd / m 2 The CIE chromaticity coordinates of light-emitting element 1 at a luminance of (x, y)=(0.55,0.45). 900cd / m 2 Comparison of light-emitting element 2 at luminance of The CIE chromaticity coordinates of 1000 cd / m are (x,y) = (0.55,0.44). 2 The CIE chromaticity coordinates of the comparison light-emitting element 3 at the luminance of The light-emitting element shown in this example is [Ir(dppm) 2 (acac)] derived from orange It was found that color emission was obtained.

[0269] 8 to 10 and Table 2, the light-emitting element 1, the comparative light-emitting element 2, and the comparative light-emitting element 3 are Both are light-emitting devices with low driving voltages and high current efficiency, power efficiency, and external quantum efficiency. It was found to be.

[0270] In particular, the light-emitting element 1 has a higher current density in a high luminance region than the comparative light-emitting element 2 and the comparative light-emitting element 3. The efficiency and external quantum efficiency were found to be high (the brightness in Figs. 8 and 10 is 1000 to 1000). 00cd / m 2 The light-emitting element 1 is a carbazole PCBBiF, which has a substituent group containing a skeleton, a fluorenyl group, and a biphenyl group, is used as the light-emitting layer. Comparative light-emitting element 2 includes a substituent having a carbazole skeleton and a P having two naphthyl groups. The comparative light-emitting element 3 contains a substituent having a carbazole skeleton, fluorine, and CBNBB in the light-emitting layer. The light-emitting layer contains PCBNBF having a naphthyl group and a phenyl group. The major difference between the comparative light-emitting element 2 and the comparative light-emitting element 3 is the tertiary amine contained in the light-emitting layer. The tertiary aryl group used in the light-emitting element 1 according to one embodiment of the present invention is whether or not the tertiary aryl group contains a naphthyl group. Since amine has a biphenylamine skeleton and a fluorenylamine skeleton, it has high hole transport properties. In addition, compared with amines containing a naphthalene skeleton, it has a high triplet excitation potential. Because of its high electromotive force, it also has excellent exciton blocking properties. This makes it possible to prevent leakage of excitons and diffusion of excitons, thereby realizing a light-emitting device that exhibits high luminous efficiency.

[0271] Next, a reliability test was performed on the light-emitting element 1, the comparative light-emitting element 2, and the comparative light-emitting element 3. The test results are shown in Figure 11 (A) and (B). In Figure 11 (A) and (B), the vertical axis represents the initial luminance. The horizontal axis shows the normalized luminance (%) when the signal is set to 100%, and the horizontal axis shows the driving time (h) of the element. The reliability test was performed at room temperature with an initial brightness of 5000 cd / m 2 and the current density is constant. As shown in FIG. 11(A) and (B), after 460 hours of operation, the light-emitting element 1 The luminance of the comparative light-emitting element 2 after 460 hours was 95% of the initial luminance. After 370 hours, the luminance of comparative light-emitting element 3 remained at 94% of its initial luminance. From the results of the reliability test, it was found that the light-emitting element 1 was It was found to have a longer life than 3.

[0272] As described above, the light-emitting element 1 according to one embodiment of the present invention does not leak electrons or emit excitons even in a high-luminance region. This prevents the diffusion of , and therefore prevents the luminescent material from emitting light through a deactivation pathway other than the radiative deactivation pathway ( Therefore, the deterioration of the luminance of the element can be reduced. Such a light-emitting element with little deterioration can be easily obtained stably with good reproducibility.

[0273] As described above, by applying one embodiment of the present invention, a high luminance efficiency is exhibited in a high luminance region. It was found that a light-emitting element having a long lifetime can be obtained by applying one embodiment of the present invention. It was found that a light-emitting device could be obtained. EXAMPLES

[0274] In this example, a light-emitting element according to one embodiment of the present invention will be described with reference to FIG. The chemical formulas of the materials used are shown below. Materials already mentioned are omitted.

[0275] [ka]

[0276] A method for fabricating the light-emitting element 4 of this example and the comparative light-emitting element 5 will be described below.

[0277] (Light emitting element 4) First, in the same manner as in the light-emitting element 1, a first electrode 1101 and a hole injection layer 1102 were formed on a glass substrate 1100. 1111 was created.

[0278] Next, a film of PCBBiF was formed on the hole injection layer 1111 to a thickness of 20 nm. A hole transport layer 1112 was formed.

[0279] In addition, 2mDBTBPDBq-II, PCBBiF, and (acetylacetonato)bis (6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [ Ir(tBuppm) 2 (acac)]) was co-evaporated onto the hole transport layer 1112 to form the light emitting layer 1 113 was formed. Here, 2mDBTBPDBq-II, PCBBiF, and [Ir (tBuppm) 2 (acac)] weight ratio is 0.7:0.3:0.05 (=2mDB TBPDBq-II:PCBBiF:[Ir(tBuppm) 2 (acac)]) The weight ratio of the layer was adjusted as follows: 0.8:0.2:0.05 ( =2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm) 2 (acac) ]) and a layer having a thickness of 20 nm was deposited.

[0280] Next, 2mDBTBPDBq-II was formed on the light-emitting layer 1113 to a thickness of 5 nm. Further, BPhen is formed into a film having a thickness of 15 nm to form an electron transport layer 1114. was formed.

[0281] Furthermore, LiF was evaporated to a thickness of 1 nm on the electron transport layer 1114 to form an electron injection layer 1115. was formed.

[0282] Finally, a 200 nm film of aluminum was deposited on the second electrode 1103, which served as the cathode. The light-emitting element 4 of this example was fabricated by depositing the material so as to have a thickness.

[0283] In the above-mentioned deposition process, the deposition was all performed by a resistance heating method.

[0284] (Comparative light-emitting element 5) The hole transport layer 1112 of the comparative light-emitting element 5 was formed by depositing PCBNBB to a thickness of 20 nm. The light-emitting layer 1113 was formed by BB, and [Ir(tBuppm) 2 (acac)] was co-evaporated. , 2mDBTBPDBq-II, PCBNBB and [Ir(tBuppm) 2 (aca c)] weight ratio was 0.7:0.3:0.05 (=2mDBTBPDBq-II:PCB NBB:[Ir(tBuppm) 2 (acac)]) A layer of 20 nm and the weight ratio is 0.8:0.2:0.05 (=2mDBTBPDBq-I I:PCBNBB:[Ir(tBuppm) 2 (acac)]) A 20 nm thick layer was laminated on the hole transport layer 1112 and the light emitting layer 1113. It was fabricated in the same manner as optical element 4.

[0285] The element structure of the light-emitting element of this example obtained as described above is shown in Table 3.

[0286] [Table 3]

[0287] The light-emitting element 4 and the comparative light-emitting element 5 were placed in a glove box with a nitrogen atmosphere. After sealing the light-emitting elements with a glass substrate to prevent them from being exposed to the atmosphere, The operating characteristics of the device were measured. The measurements were performed at room temperature (an atmosphere maintained at 25°C). Ta.

[0288] The luminance vs. current efficiency characteristics of the light-emitting element of this embodiment are shown in FIG. 12. In FIG. 12, the horizontal axis indicates the luminance (cd / m 2 The vertical axis represents the current efficiency (cd / A), and the voltage-luminance characteristics are shown in Figure 13. In FIG. 13, the horizontal axis is voltage (V) and the vertical axis is luminance (cd / m 2 ) and also represents brightness. The luminance-power efficiency characteristics are shown in FIG. 14. In FIG. 14, the horizontal axis is luminance (cd / m 2 )of, The vertical axis represents the power efficiency (lm / W). The luminance vs. external quantum efficiency characteristics are shown in Figure 15. In FIG. 15, the horizontal axis represents luminance (cd / m 2 ) and the vertical axis represents the external quantum efficiency (%). The luminance of the light-emitting element 4 and the comparative light-emitting element 5 was 900 cd / m 2 Voltage when (V ), current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power The power efficiency (lm / W) and external quantum efficiency (%) are shown in Table 4.

[0289] [Table 4]

[0290] As shown in Table 4, 900cd / m 2 The CIE chromaticity coordinates of light-emitting element 4 at the luminance of (x, y )=(0.41, 0.59), and the CIE chromaticity coordinates of the comparative light-emitting element 5 are (x, y)=( 0.40, 0.59). The light-emitting element 4 and the comparative light-emitting element 5 had an emission constant of [Ir(tBupp m) 2 It was found that green luminescence originating from (acac)] was obtained.

[0291] 12 to 15 and Table 4, the light-emitting element 4 and the comparative light-emitting element 5 both exhibited a high luminance at a driving voltage Furthermore, the current efficiency of the light-emitting element 4 was significantly lower than that of the comparative light-emitting element 5. The efficiency, power efficiency, and external quantum efficiency were found to be high (Fig. 12, Fig. 14, or Fig. 15 brightness is 1000~10000cd / m 2 Current efficiency, power efficiency, or external quantity See Child Efficiency.

[0292] The light-emitting element 4 has a substituent containing a carbazole skeleton, a fluorenyl group, and a biphenyl group. The comparative light-emitting element 5 contains PCBBiF, which has a carbazole skeleton, in the light-emitting layer and the hole-transporting layer. The light-emitting layer and the hole-transporting layer contain PCBNBB having a substituent containing the substituent and two naphthyl groups. That is, the major difference between the light-emitting element 4 and the comparative light-emitting element 5 is the tertiary aryl group contained in the light-emitting layer. The tertiary amine used in the light-emitting element 4 according to one embodiment of the present invention is a naphthyl group. The amine has a biphenylamine skeleton and a fluorenylamine skeleton, and therefore has high hole transport properties. In addition to its high electron transport and blocking properties, it has a triplet charge ratio lower than amines that contain a naphthalene skeleton. Because of its high excitation energy, it also has excellent exciton blocking properties. Therefore, even in the high brightness range, This makes it possible to prevent electron leakage and exciton diffusion, thereby realizing light-emitting devices with high luminous efficiency. This difference is due to the fact that the same compound as the tertiary amine contained in the light-emitting layer is used as the tertiary amine in this example. When the compound is used in a hole transport layer, the amount of the charge transporting agent is larger. By using the same compound as the tertiary amine contained in the light-emitting layer in the hole transport layer, The voltage is reduced for both devices, but without the application of an embodiment of the present invention (see the general formula above). (G0)), the luminous efficiency of the comparative light-emitting element 5 is low. It will decrease.

[0293] As described above, by applying one embodiment of the present invention, a high luminance efficiency is exhibited in a high luminance region. In addition, it was found that a light-emitting element can be obtained. In particular, the first organic compound (embodiment The compound represented by the general formula (G0) shown in Form 1 is also used in the hole transport layer, It was found that a light-emitting element with high light efficiency could be obtained.

[0294] Next, a reliability test was performed on the light-emitting element 4 and the comparative light-emitting element 5. The results of the reliability test are shown in FIG. In FIG. 16, the vertical axis indicates normalized luminance (%) when the initial luminance is set to 100%. The horizontal axis indicates the driving time (h) of the element. The reliability test was performed at room temperature, and the initial luminance was 5000 cd / m 2 The light emitting device of this example was driven under the condition of a constant current density. The luminance of the light-emitting element 4 after 160 hours was maintained at 93% of the initial luminance, and the luminance of the comparative light-emitting element 5 after 160 hours was maintained at 93% of the initial luminance. After 360 hours, the brightness remained at 89% of the initial brightness. EXAMPLES

[0295] In this example, a light-emitting element according to one embodiment of the present invention will be described with reference to FIG. The chemical formulas of the materials used are shown below. Materials already mentioned are omitted.

[0296] [ka]

[0297] A method for fabricating the light-emitting elements 6 and 7 of this example will be described below.

[0298] (Light emitting element 6) First, in the same manner as in the light-emitting element 1, a first electrode 1101 and a hole injection layer 1102 were formed on a glass substrate 1100. 1111 was created.

[0299] Next, on the hole injection layer 1111, N-(1,1'-biphenyl-4-yl)-N-[4- (9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9 H-fluorene]-2-amine (abbreviation: PCBBiSF) was applied to a thickness of 20 nm. A film was formed to form a hole transporting layer 1112 .

[0300] In addition, 2mDBTBPDBq-II, PCBBiSF, and [Ir(dppm) 2 (a cac) were co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. , 2mDBTBPDBq-II, PCBBiSF, and [Ir(dppm) 2 (acac )] weight ratio was 0.7:0.3:0.05 (=2mDBTBPDBq-II:PCBB iSF:[Ir(dppm) 2 (acac)]) was adjusted to a thickness of 20 nm layer, and the weight ratio is 0.8:0.2:0.05 (=2mDBTBPDBq-II: PCBBiSF:[Ir(dppm) 2 (acac)]) was adjusted to form a film. A layer having a thickness of 20 nm was laminated.

[0301] Next, 2mDBTBPDBq-II was formed on the light-emitting layer 1113 to a thickness of 20 nm. Further, BPhen is formed into a film having a thickness of 20 nm to form an electron transport layer 111. 4 was formed.

[0302] Furthermore, LiF was evaporated to a thickness of 1 nm on the electron transport layer 1114 to form an electron injection layer 1115. was formed.

[0303] Finally, a 200 nm film of aluminum was deposited on the second electrode 1103, which served as the cathode. The light-emitting element 6 of this example was fabricated by vapor deposition so as to have a thickness.

[0304] In the above-mentioned deposition process, the deposition was all performed by a resistance heating method.

[0305] (Light emitting element 7) The hole transport layer 1112 of the light emitting element 7 is formed by depositing BPAFLP to a thickness of 20 nm. The layers other than the hole transport layer 1112 were fabricated in the same manner as in the light-emitting element 6.

[0306] The element structure of the light-emitting element of this example obtained as described above is shown in Table 5.

[0307] [Table 5]

[0308] The light emitting element 6 and the light emitting element 7 are placed in a glove box with a nitrogen atmosphere. After sealing the light-emitting elements with a glass substrate to prevent them from being exposed to the air, The operating characteristics were measured at room temperature (an atmosphere maintained at 25°C).

[0309] The luminance vs. current efficiency characteristics of the light-emitting element of this embodiment are shown in FIG. 17. In FIG. 17, the horizontal axis indicates the luminance (cd / m 2 The vertical axis represents the current efficiency (cd / A), and the voltage-luminance characteristics are shown in Figure 18. In FIG. 18, the horizontal axis is voltage (V) and the vertical axis is luminance (cd / m 2 ) and also represents brightness. The luminance-power efficiency characteristics are shown in FIG. 19. In FIG. 19, the horizontal axis is luminance (cd / m 2 )of, The vertical axis represents the power efficiency (lm / W). The luminance vs. external quantum efficiency characteristics are shown in Figure 20. In FIG. 20, the horizontal axis is luminance (cd / m 2 ) and the vertical axis represents the external quantum efficiency (%). Furthermore, the luminance of the light-emitting element 6 and the light-emitting element 7 is 1000 cd / m 2 Voltage when near V), current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), The power efficiency (lm / W) and external quantum efficiency (%) are shown in Table 6.

[0310] [Table 6]

[0311] As shown in Table 6, 900cd / m 2 The CIE chromaticity coordinates of light-emitting element 6 at a luminance of (x, y )=(0.56,0.44), which is 1000 cd / m 2 CI of light-emitting element 7 at brightness of The E chromaticity coordinates were (x, y) = (0.55, 0.44). is [Ir(dppm) 2 (acac)] was found to have orange luminescence. .

[0312] 17 to 20 and Table 6, both the light-emitting element 6 and the light-emitting element 7 have a low driving voltage. It was found that the light-emitting device had high current efficiency, power efficiency, and external quantum efficiency. Tertiary amine used in the light-emitting layer of the light-emitting element 6 and the light-emitting element 7 which are one embodiment of the present invention Since it has a biphenylamine skeleton and a spirofluorenylamine skeleton, it has high hole transport properties. In addition to its excellent transmittance and electron blocking properties, it also has excellent exciton blocking properties. This light-emitting device can prevent electron leakage and exciton diffusion even in the high-temperature region, and exhibits high luminous efficiency. In addition, in one embodiment of the present invention, as in the light-emitting element 6, the first By using the same compound as the tertiary amine in the hole transport layer, The driving voltage can be reduced (without reducing the light efficiency). EXAMPLES

[0313] In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIG. The materials used in the examples are those whose chemical formulas have already been shown.

[0314] A method for fabricating the light-emitting element 8 of this example and the comparative light-emitting element 9 will be described below.

[0315] (Light emitting element 8) First, similarly to the light-emitting element 1, a first electrode 1101 and a hole injection layer 1102 were formed on a glass substrate 1100. The hole injection layer 1111 and the hole transport layer 1112 were formed. nm.

[0316] Next, 2mDBTBPDBq-II, PCBBiF, and [Ir(dppm) 2 (aca c)] was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. DBTBPDBq-II, PCBBiF, and [Ir(dppm) 2 (acac)] weight The ratio of the amounts was 0.7:0.3:0.05 (=2mDBTBPDBq-II:PCBBiF:[ Ir(dppm) 2 (acac)]) and a 20 nm thick layer was deposited. , the weight ratio is 0.8:0.2:0.05(=2mDBTBPDBq-II:PCBBi F: [Ir(dppm) 2 (acac)]) and the thickness of the film was adjusted to 20 nm. A layer of the above was laminated.

[0317] Next, 2mDBTBPDBq-II was formed on the light-emitting layer 1113 to a thickness of 20 nm. Further, BPhen is formed into a film having a thickness of 20 nm to form an electron transport layer 111. 4 was formed.

[0318] Then, LiF was evaporated to a thickness of 1 nm on the electron transport layer 1114 to form an electron injection layer 1115. was formed.

[0319] Finally, a 200 nm film of aluminum was deposited on the second electrode 1103, which served as the cathode. The light-emitting element 8 of this example was fabricated by depositing the material so as to have a thickness.

[0320] In the above-mentioned deposition process, the deposition was all performed by a resistance heating method.

[0321] (Comparative light-emitting element 9) The light-emitting layer 1113 of the comparative light-emitting element 9 contains 2mDBTBPDBq-II and [Ir(dppm ) 2 (acac)] was co-evaporated. and [Ir(dppm) 2 The weight ratio of (acac) was 1:0.05 (=2mDBTBP DBq-II: [Ir(dppm) 2 (acac)]). The thickness of the light-emitting layer 1113 was 40 nm. 2mDBTBPDBq-II was deposited to a thickness of 10 nm, and BPhen was The film was formed to a thickness of 15 nm. It was fabricated in the same manner as for element 8.

[0322] The element structure of the light-emitting element of this example obtained as described above is shown in Table 7.

[0323] [Table 7]

[0324] The light-emitting element 8 and the comparative light-emitting element 9 were placed in a glove box with a nitrogen atmosphere. After sealing the elements with a glass substrate to prevent them from being exposed to the atmosphere, The operating characteristics of the device were measured. The measurements were performed at room temperature (25°C). I did.

[0325] The voltage-current characteristics of the light-emitting device of this embodiment are shown in FIG. 27. In FIG. 27, the horizontal axis represents voltage (V The vertical axis represents the current (mA), and the luminance vs. external quantum efficiency characteristics are shown in FIG. In this figure, the horizontal axis is luminance (cd / m 2 ) and the vertical axis represents the external quantum efficiency (%). The emission spectrum of the light-emitting element of this embodiment is shown in FIG. 000cd / m 2 Voltage (V) and current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm / W), and external quantum efficiency (%) are shown. Shown in Figure 8.

[0326] [Table 8]

[0327] As shown in Table 8, 960cd / m 2 The CIE chromaticity coordinates of light-emitting element 8 at a luminance of (x, y )=(0.56,0.44). 1100cd / m 2 Comparison of light-emitting elements at luminance of 9 The CIE chromaticity coordinates of were (x, y) = (0.56, 0.44). The element is [Ir(dppm) 2 (acac)] was observed. I did.

[0328] The light-emitting element 8 has a light emission rate of 1000 cd / m 2 The external quantum efficiency is 31% (current efficiency is 85 cd / A), which is an extremely high ratio with no energy transfer from the exciplex. The value was higher than that of the comparative light emitting element 9.

[0329] The light emitting element 8 has a luminance of 1000 cd / m 2 The voltage in the vicinity is extremely low at 2.8V. The value was lower than that of the comparative light-emitting element 9.

[0330] Next, a reliability test was performed on the light-emitting element 8 and the comparative light-emitting element 9. The results of the reliability test are shown in FIG. In FIG. 30, the vertical axis indicates normalized luminance (%) when the initial luminance is 100%. The horizontal axis indicates the driving time (h) of the element. The reliability test was performed at room temperature, and the initial luminance was 5000 cd / m 2 The light emitting device of this example was driven under the condition of a constant current density. The luminance of the light-emitting element 8 after 3400 hours was 89% of the initial luminance, and the luminance of the comparative light-emitting element 9 After 230 hours, the brightness was less than 89% of the initial brightness. It was clear that the optical element 8 had a longer life than the comparative light-emitting element 9.

[0331] As described above, by applying one embodiment of the present invention, a light-emitting element having high emission efficiency can be obtained. In addition, it was found that a light-emitting element having a long lifetime can be obtained by applying one embodiment of the present invention. It was found that this could be done. EXAMPLES

[0332] In this example, a light-emitting element according to one embodiment of the present invention will be described with reference to FIG. The chemical formulas of the materials used are shown below. Materials already mentioned are omitted.

[0333] [ka]

[0334] The methods for fabricating the light-emitting element 10, the light-emitting element 11, and the comparative light-emitting element 12 of this example are described below. The structure and fabrication method of each light-emitting element in this example other than the light-emitting layer are the same as those of light-emitting element 8. Since the configuration of the light-emitting layer in each light-emitting element of this embodiment is the same as that in the embodiment 1, the description thereof will be omitted. The manufacturing method will be described.

[0335] (Light emitting element 10) In the light-emitting device 10, 2mDBTBPDBq-II, N-(4-biphenyl)-N-(9, 9-Dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole-3 -amine (abbreviation: PCBiF), and [Ir(dppm) 2 (acac)] was co-evaporated, The light-emitting layer 1113 was formed on the hole-transporting layer 1112. II, PCBiF, and [Ir(dppm) 2 (acac)] by weight ratio is 0.7:0. 3:0.05(=2mDBTBPDBq-II:PCBiF:[Ir(dppm) 2 (a cac)) and the weight ratio was adjusted to 0.8: 0.2:0.05(=2mDBTBPDBq-II:PCBiF:[Ir(dppm) 2 A 20 nm thick layer was then laminated on the film, with the film thickness adjusted to be (acac)].

[0336] (Light emitting element 11) In the light-emitting device 11, 2mDBTBPDBq-II, N-(4-biphenyl)-N-(9, 9'-Spirobi[9H-fluoren]-2-yl)-9-phenyl-9H-carbazole -3-amine (abbreviation: PCBiSF), and [Ir(dppm) 2 (acac)] The light-emitting layer 1113 was formed on the hole transport layer 1112. Bq-II, PCBiSF, and [Ir(dppm) 2 (acac)] by weight ratio is 0. 7:0.3:0.05(=2mDBTBPDBq-II:PCBiSF:[Ir(dpp m) 2 (acac)]) and a layer having a thickness of 20 nm was formed by adjusting the weight ratio of , 0.8:0.2:0.05(=2mDBTBPDBq-II:PCBiSF:[Ir( dppm) 2 (acac)]) and a 20 nm thick layer was deposited. did.

[0337] (Comparative light-emitting element 12) In the comparative light-emitting element 12, 2mDBTBPDBq-II, 2-[N-(9-phenylcarba 3-(3-yl)-N-phenylamino]-spiro-9,9'-bifluorene (abbreviation: PCASF), and [Ir(dppm) 2 (acac)] was co-evaporated to form a hole transport layer 111 An emission layer 1113 was formed on the substrate 2. Here, 2mDBTBPDBq-II, PCASF , and [Ir(dppm) 2 (acac)] weight ratio is 0.7:0.3:0.05 (= 2mDBTBPDBq-II:PCASF:[Ir(dppm) 2 (acac)]) The weight ratio of the layer was adjusted to 0.8:0.2:0.05. (=2mDBTBPDBq-II:PCASF:[Ir(dppm) 2 (acac)]) Then, a layer having a thickness of 20 nm was laminated on the substrate.

[0338] The element structure of the light-emitting element of this example obtained as described above is shown in Table 9.

[0339] [Table 9]

[0340] The light-emitting element 10, the light-emitting element 11, and the comparative light-emitting element 12 were placed in a glove box with a nitrogen atmosphere. Inside the device, each light-emitting element is sealed with a glass substrate to prevent it from being exposed to the atmosphere. After that, the operating characteristics of these light-emitting devices were measured. The event was held in a well-maintained atmosphere.

[0341] The luminance vs. current efficiency characteristics of the light-emitting element of this embodiment are shown in FIG. 31. In FIG. 31, the horizontal axis indicates luminance (cd / m 2 The vertical axis represents the current efficiency (cd / A), and the voltage-luminance characteristics are shown in Figure 32. In FIG. 32, the horizontal axis is voltage (V) and the vertical axis is luminance (cd / m 2 ) and also represents brightness. The luminance vs. external quantum efficiency characteristics are shown in FIG. 33. In FIG. 33, the horizontal axis is luminance (cd / m 2 )of The vertical axis represents the external quantum efficiency (%). The luminance of each light-emitting element is 1000 cd / m 2 Voltage (V) and current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), electric The current efficiency (cd / A), power efficiency (lm / W), and external quantum efficiency (%) are shown in Table 10.

[0342] [Table 10]

[0343] As shown in Table 10, 1000cd / m 2 The CIE chromaticity coordinates of each light-emitting element at a luminance of (x, y)=(0.57, 0.43). The light-emitting element shown in this example has an emitting property of [Ir(d ppm) 2 It was found that orange luminescence originating from the cation exchange reaction (cation (acac)) was obtained.

[0344] 32 and Table 10, the driving voltages of the light-emitting element 10, the light-emitting element 11, and the comparative light-emitting element 12 31, 33, and Table 10, the light-emitting element 10 The light-emitting element 11 has higher current efficiency, power efficiency, and external quantum efficiency than the comparative light-emitting element 12. Both were found to be high.

[0345] Next, a reliability test was performed on the light-emitting element 10, the light-emitting element 11, and the comparative light-emitting element 12. The results of the performance test are shown in Figure 34. In Figure 34, the vertical axis indicates the standard deviation when the initial luminance is 100%. The horizontal axis indicates the rated luminance (%), and the horizontal axis indicates the operation time (h) of the element. The reliability test was performed at room temperature. , initial brightness 5000cd / m 2 The light emitting device of this embodiment was operated under a constant current density condition. As can be seen from FIG. 34, the luminance of the light-emitting element 10 after 660 hours was maintained at 94% of the initial luminance. The luminance of the light-emitting element 11 after 660 hours was 93% of the initial luminance, The brightness of the sample 12 after 660 hours was less than 87% of the initial brightness. From this, it is clear that the light-emitting elements 10 and 11 have a longer life than the comparative light-emitting element 12. It became clear.

[0346] The light-emitting element 11 has a substituent having a carbazole skeleton, a spirofluorenyl group, and a biphenyl group. The comparative light-emitting element 12 contains PCBiSF having a carbazole skeleton in the light-emitting layer. The light-emitting layer contains PCASF having a substituent containing fluorenyl, a spirofluorenyl group, and a phenyl group. That is, the difference between the light-emitting element 11 and the comparative light-emitting element 12 is the tertiary amine contained in the light-emitting layer. The only difference is that the substituent of the aryl group is a biphenyl group or a phenyl group. The tertiary amine used in 1 has a highly reactive phenylamine skeleton with the 4-position of the phenyl group substituted with a phenyl group. By capping the compound with a p-biphenylamine group, a reliable p-biphenylamine structure is formed. A high-performance light-emitting element can be realized.

[0347] As described above, by applying one embodiment of the present invention, a light-emitting element having high emission efficiency can be obtained. In addition, it has been found that a light-emitting element having a long lifetime can be obtained by applying one embodiment of the present invention. It was found that it can be obtained. EXAMPLES

[0348] In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIG. The materials used in the examples are those whose chemical formulas have already been shown.

[0349] The following are light-emitting elements 13, 14, and 15 of this example, and a comparative light-emitting element 16. The fabrication method of each light-emitting element in this example is as follows. The structure and fabrication method are the same as those of the light-emitting element 8, so the description will be omitted. The structures and manufacturing methods of the light-emitting layer and the electron transport layer in the light-emitting element will be described.

[0350] (Light emitting element 13) In the light-emitting device 13, 2mDBTBPDBq-II, PCBBiF, and [Ir(tBup pm) 2 (acac)] was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. Here, 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 2 (acac)] weight ratio was 0.7:0.3:0.05 (=2mDBTBPDBq-I I:PCBBiF:[Ir(tBuppm) 2 (acac)]) The layer was 20 nm thick and the weight ratio was 0.8:0.2:0.05 (=2mDBTBP DBq-II:PCBBiF:[Ir(tBuppm) 2 (acac)]) A 20 nm thick layer was then laminated on the film.

[0351] (Light emitting element 14) In the light-emitting element 14, 2mDBTBPDBq-II, PCBiF, and [Ir(tBupp m) 2 (acac)] was co-evaporated to form a light-emitting layer 1113 on the hole-transporting layer 1112. Here, 2mDBTBPDBq-II, PCBiF, and [Ir(tBuppm) 2 ( acac)] weight ratio was 0.7:0.3:0.05 (=2mDBTBPDBq-II: PCBiF:[Ir(tBuppm) 2 (acac)]) was adjusted and the film was formed. A layer of 20 nm thickness and the weight ratio is 0.8:0.2:0.05 (=2mDBTBPDBq -II:PCBiF:[Ir(tBuppm) 2 (acac)]) The deposited layer having a thickness of 20 nm was laminated.

[0352] (Light emitting element 15) In the light-emitting device 15, 2mDBTBPDBq-II, PCBiSF, and [Ir(tBup pm) 2 (acac)] was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. Here, 2mDBTBPDBq-II, PCBiSF, and [Ir(tBuppm) 2 (acac)] weight ratio was 0.7:0.3:0.05 (=2mDBTBPDBq-I I:PCBiSF:[Ir(tBuppm) 2 (acac)]) The layer was 20 nm thick and the weight ratio was 0.8:0.2:0.05 (=2mDBTBP DBq-II:PCBiSF:[Ir(tBuppm) 2 (acac)]) A 20 nm thick layer was then laminated on the film.

[0353] (Comparative light-emitting element 16) In the comparative light-emitting element 16, 2mDBTBPDBq-II, PCASF, and [Ir(tBu ppm) 2 (acac)] was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. Here, 2mDBTBPDBq-II, PCASF, and [Ir(tBuppm) 2 (acac)] weight ratio was 0.7:0.3:0.05 (=2mDBTBPDBq-I I:PCASF:[Ir(tBuppm) 2 (acac)]) and then the film was formed. The weight ratio of the layer was 0.8:0.2:0.05 (=2mDBTBPD Bq-II:PCASF:[Ir(tBuppm) 2 (acac)]) Then, a 20 nm thick layer was formed by depositing the SiO 2 film.

[0354] The light-emitting elements 13, 14, and 15 of this embodiment and the comparative light-emitting element 16 Then, 2mDBTBPDBq-II was deposited on the light-emitting layer 1113 to a thickness of 10 nm. Furthermore, BPhen is formed into a film having a thickness of 15 nm to form an electron transport layer 111. 4 was formed.

[0355] The element structure of the light-emitting element of this example obtained as described above is shown in Table 11.

[0356] [Table 11]

[0357] The light-emitting element 13, the light-emitting element 14, the light-emitting element 15, and the comparative light-emitting element 16 were subjected to a nitrogen atmosphere test. Inside the lobe box, each light-emitting element is sealed with a glass substrate to prevent it from being exposed to the atmosphere. After the above-mentioned work, the operating characteristics of these light-emitting devices were measured. The experiment was carried out at room temperature (atmosphere maintained at 25°C).

[0358] The luminance vs. current efficiency characteristics of the light-emitting element of this embodiment are shown in FIG. 35. In FIG. 35, the horizontal axis indicates luminance. (cd / m 2 The vertical axis represents the current efficiency (cd / A), and the voltage-luminance characteristics are shown in Figure 36. In FIG. 36, the horizontal axis is voltage (V) and the vertical axis is luminance (cd / m 2 ) and also represents brightness. The luminance vs. external quantum efficiency characteristics are shown in FIG. 37. In FIG. 37, the horizontal axis is luminance (cd / m2 )of The vertical axis represents the external quantum efficiency (%). The luminance of each light-emitting element is 1000 cd / m 2 Voltage (V) and current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), electric The current efficiency (cd / A), power efficiency (lm / W), and external quantum efficiency (%) are shown in Table 12.

[0359] [Table 12]

[0360] As shown in Table 12, 860cd / m 2 The CIE chromaticity coordinates of the light-emitting element 13 at a luminance of (x ,y)=(0.41,0.58). 970cd / m 2 luminance of 14 The CIE chromaticity coordinates of 1000 cd / m are (x,y) = (0.41,0.58). 2 The CIE chromaticity coordinates of the light-emitting element 15 at this luminance are (x, y) = (0.42, 0.57). 1100cd / m 2 The CIE chromaticity coordinates of the comparison light-emitting element 16 at the luminance of (x,y) are =(0.42, 0.57). The light-emitting element shown in this example has an ) 2 It was found that yellow-green luminescence originating from (acac)] was obtained.

[0361] 35 to 37 and Table 12, the light-emitting element 13, the light-emitting element 14, the light-emitting element 15, and The comparative light-emitting element 16 has a low driving voltage, and has high current efficiency, power efficiency, and external quantum efficiency. It was found that each of them was a high-performance light-emitting element.

[0362] Next, reliability tests of the light-emitting element 13, the light-emitting element 14, the light-emitting element 15, and the comparative light-emitting element 16 were performed. The results of the reliability test are shown in FIG. 38. In FIG. 38, the vertical axis indicates the initial luminance from 100 The horizontal axis shows the normalized luminance (%) when the brightness is 1.0%, and the horizontal axis shows the driving time (h) of the element. The test was performed at room temperature with an initial brightness of 5000 cd / m 2 This experiment was carried out under a constant current density condition. As shown in FIG. 38, the luminance of the light-emitting element 13 after 520 hours was 1 / 100 of the initial luminance. After 600 hours, the luminance of the light-emitting element 14 remained at 84% of the initial luminance. The luminance of the light-emitting element 15 after 520 hours was 85% of the initial luminance, The brightness of 16 after 600 hours was less than 75% of the initial brightness. The light-emitting element 13, the light-emitting element 14, and the light-emitting element 15 have a longer life than the comparative light-emitting element 16. It became clear that...

[0363] As described above, the luminance of the light-emitting element 15 after 520 hours was 85% of the initial luminance. The luminance of the comparative light emitting element 16 after 520 hours was less than 77% of the initial luminance. The element 15 is a compound having a substituent containing a carbazole skeleton, a spirofluorenyl group, and a biphenyl group. The comparative light-emitting element 16 contains PCBiSF having a carbazole skeleton in the light-emitting layer. The light-emitting layer contains PCASF having a substituent, a spirofluorenyl group, and a phenyl group. That is, the difference between the light-emitting element 15 and the comparative light-emitting element 16 is the amount of the tertiary amine contained in the light-emitting layer. The only difference is whether the substituent is a biphenyl group or a phenyl group. The tertiary amine used had a highly reactive phenylamine skeleton with the 4-position of the phenyl group substituted with a phenyl group. By capping with a p-biphenylamine group, a highly reliable A light emitting element can be realized.

[0364] As described above, by applying one embodiment of the present invention, a light-emitting element having high emission efficiency can be obtained. In addition, it has been found that a light-emitting element having a long lifetime can be obtained by applying one embodiment of the present invention. It was found that it can be obtained. EXAMPLES

[0365] In this example, a light-emitting element according to one embodiment of the present invention will be described with reference to FIG. The chemical formulas of the materials used are shown below. Materials already mentioned are omitted.

[0366] [ka]

[0367] A method for fabricating the light emitting device 17 of this example will be described below.

[0368] (Light emitting element 17) First, similarly to the light-emitting element 8, a first electrode 1101 and a hole injection layer 1102 were formed on a glass substrate 1100. A layer 111 and a hole transport layer 1112 were formed.

[0369] Next, 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation Name: 4,6mCzP2Pm), PCBBiF, and [Ir(tBuppm) 2 (acac )] was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. mCzP2Pm, PCBBiF, and [Ir(tBuppm) 2 (acac)] weight ratio However, 0.7:0.3:0.05(=4,6mCzP2Pm:PCBBiF:[Ir(tB uppm) 2 (acac)]) and a 20 nm thick layer was formed. The ratio of the amounts was 0.8:0.2:0.05 (=4,6mCzP2Pm:PCBBiF:[Ir( tBuppm) 2 (acac)]) and a 20 nm thick layer was deposited. Layered.

[0370] Next, a film of 4,6mCzP2Pm was formed on the light-emitting layer 1113 to a thickness of 15 nm. Furthermore, BPhen is deposited to a thickness of 10 nm to form an electron transport layer 1114. Successful.

[0371] Then, LiF was evaporated to a thickness of 1 nm on the electron transport layer 1114 to form an electron injection layer 1115. was formed.

[0372] Finally, a 200 nm film of aluminum was deposited on the second electrode 1103, which served as the cathode. The light emitting element 17 of this example was fabricated by depositing the material so as to have a thickness of 100 nm.

[0373] In the above-mentioned deposition process, the deposition was all performed by a resistance heating method.

[0374] The element structure of the light-emitting element of this example obtained as described above is shown in Table 13.

[0375] [Table 13]

[0376] The light emitting element 17 is placed in a glove box with a nitrogen atmosphere so that the light emitting element is not exposed to the air. After sealing the light-emitting elements with a glass substrate, the operating characteristics of the light-emitting elements were The measurements were carried out at room temperature (an atmosphere maintained at 25°C).

[0377] The luminance vs. current efficiency characteristics of the light-emitting element of this embodiment are shown in FIG. 39. In FIG. 39, the horizontal axis indicates luminance. (cd / m 2 The vertical axis represents the current efficiency (cd / A), and the voltage-luminance characteristics are shown in Figure 40. In FIG. 40, the horizontal axis is voltage (V) and the vertical axis is luminance (cd / m 2 ) and also represents brightness. The luminance vs. external quantum efficiency characteristics are shown in FIG. 41. In FIG. 41, the horizontal axis is luminance (cd / m 2 )of The vertical axis represents the external quantum efficiency (%). The luminance of the light-emitting element 17 is 760 cd / m 2 Voltage (V) and current density (mA / cm 2 ), CIE chromaticity coordinates (x, y), current efficiency The efficiency (cd / A), power efficiency (lm / W), and external quantum efficiency (%) are shown in Table 14.

[0378] [Table 14]

[0379] As shown in Table 14, 760cd / m 2 The CIE chromaticity coordinates of the light-emitting element 17 at a luminance of (x , y)=(0.41, 0.58). uppm) 2 It was found that orange luminescence originating from the cation exchange reaction (cation (acac)) was obtained.

[0380] 39 to 41 and Table 14, the light-emitting element 17 has a low driving voltage, a high current efficiency, and a high power. It was found that this was a light-emitting device with high light-emitting efficiency and external quantum efficiency.

[0381] Next, a reliability test was conducted on the light-emitting element 17. The results of the reliability test are shown in FIG. In the graph, the vertical axis indicates the normalized luminance (%) when the initial luminance is 100%, and the horizontal axis indicates the driving time of the element. The reliability test was performed at room temperature with an initial brightness of 5000 cd / m 2 Set to The light-emitting element of this example was driven under the condition of a constant current density. After 180 hours, the brightness remained at 90% of the initial brightness.

[0382] As described above, by applying one embodiment of the present invention, a light-emitting element having high emission efficiency can be obtained. In addition, it was found that a light-emitting element having a long lifetime can be obtained by applying one embodiment of the present invention. It was found that this could be done.

[0383] (Reference example 1) The N-(1,1) compound represented by the following structural formula (128) used in Examples 1, 2 and 4 was '-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl] PCBBi The synthesis method of F) will be explained.

[0384] [ka]

[0385] <Step 1: N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-phenyl Synthesis of 9H-fluorenyl-2-amine The synthetic scheme of step 1 is shown in (x-1).

[0386] [ka]

[0387] In a 1L three-neck flask, add N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-9 H-fluoren-2-amine 45g (0.13mol) and sodium tert-butoxy 36g (0.38mol) of cid, 21g (0.13mol) of bromobenzene, and The mixture was degassed by stirring under reduced pressure. The inside of the flask was replaced with nitrogen. Then, bis(dibenzylideneacetone)palladium(0) 0. 8g (1.4mmol) and tri(tert-butyl)phosphine (10wt% in hexane 12 mL (5.9 mmol) of the solution was added.

[0388] The mixture was stirred at 90°C for 2 hours under a nitrogen stream. Then, the mixture was cooled to room temperature. The solid was filtered off by suction filtration. The obtained filtrate was concentrated to obtain about 200 mL of a brown liquid. This brown liquid was mixed with toluene, and the resulting solution was then filtered through Celite (Wako Pure Chemical Industries, Ltd.). Co., Ltd., Catalog Number: 531-16855. The same applies to Celite described below. (However, repeated description will be omitted), alumina, Florisil (Wako Pure Chemical Industries, Ltd., Catalog number: 540-00135. The same applies to Florisil described below. The filtrate was concentrated to give a pale yellow liquid. When this pale yellow liquid was recrystallized with hexane, the target pale yellow powder was obtained in a yield of 52 g. The success rate was 95%.

[0389] <Step 2: N-(1,1'-biphenyl-4-yl)-N-(4-bromophenyl) Synthesis of -9,9-dimethyl-9H-fluoren-2-amine> The synthetic scheme of step 2 is shown in (x-2).

[0390] [ka]

[0391] In a 1L Mayer flask, add N-(1,1'-biphenyl-4-yl)-9,9-dimethyl 45 g (0.10 mol) of N-phenyl-9H-fluorene-2-amine was added to the flask. 225 mL of benzene was added and dissolved by stirring under heating. After cooling the solution to room temperature, 225 mL of ethyl acetate was added to the mixture, and 18 g ( 0.10 mol) was added and stirred at room temperature for 2.5 hours. The organic layer was washed three times with an aqueous solution of sodium bicarbonate and once with saturated saline. Magnesium was added, and the mixture was left to stand for 2 hours and dried. The ammonia was removed, and the resulting filtrate was concentrated to give a yellow liquid. The solution was purified using Celite, alumina, and Florisil. The solution was concentrated to give a pale yellow solid, which was then recrystallized from toluene / ethanol. As a result, 47 g of a white powder, which was the target substance, was obtained in a yield of 89%.

[0392] <Step 3: Synthesis of PCBBiF> The synthetic scheme of step 3 is shown in (x-3).

[0393] [ka]

[0394] In a 1L three-neck flask, add N-(1,1'-biphenyl-4-yl)-N-(4-bromophenyl) 41g (80mmol) of 9,9-dimethyl-9H-fluoren-2-amine, Add 25 g (88 mmol) of phenyl-9H-carbazole-3-boronic acid and add toluene. 240mL, 80mL of ethanol, and 120mL of potassium carbonate solution (2.0mol / L) The mixture was degassed by stirring under reduced pressure, and after degassing, the flask was filled with nitrogen. In addition, 27 mg (0.12 mmol) of palladium(II) acetate and tri(ol) were added. Add 154 mg (0.5 mmol) of tri-tolylphosphine and stir again while reducing the pressure. After degassing, the atmosphere in the flask was replaced with nitrogen. The mixture was stirred at 0° C. for 1.5 hours.

[0395] After that, the mixture was allowed to cool to room temperature while stirring, and the aqueous layer of the mixture was extracted twice with toluene. The resulting extract and the organic layer were combined and washed twice with water and twice with saturated saline. Magnesium sulfate was added to the solution, which was then left to stand and dried. The mixture was then gravity filtered to remove magnesium sulfate. The nesium was removed, and the filtrate was concentrated to give a brown solution. After mixing, the resulting solution was purified through Celite, alumina, and Florisil. The filtrate was concentrated to give a pale yellow solid. The pale yellow solid was purified by distillation with ethyl acetate / ethanol. The objective product was obtained as a pale yellow powder in an amount of 46 g and a yield of 88%.

[0396] The resulting pale yellow powder (38 g) was purified by train sublimation. The light yellow powder was heated to 345℃ under the conditions of a pressure of 3.7 Pa and an argon flow rate of 15 mL / min. After purification by sublimation, the target pale yellow solid was obtained in a yield of 31 g and a recovery rate of 83%.

[0397] Nuclear magnetic resonance (NMR) analysis confirmed that this compound was the target N-(1,1'-biphenyl) -N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl ]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF) It was confirmed that.

[0398] The pale yellow solid obtained 1 The 1 H NMR data is shown below. 1 H NMR (CDCl 3 ,500MHz): δ=1,45(s, 6H), 7.18( d, J=8.0Hz, 1H), 7.27-7.32(m, 8H), 7.40-7.50( m, 7H), 7.52-7.53(m, 2H), 7.59-7.68(m, 12H), 8 .19(d, J=8.0Hz, 1H), 8.36(d, J=1.1Hz, 1H).

[0399] Also, 1 The H NMR chart is shown in FIG. 21. Note that FIG. 21(B) shows the same H NMR chart as FIG. 21(A). This is an expanded chart showing the range of 6.00 ppm to 10.0 ppm.

[0400] The absorption spectrum of a toluene solution of PCBBiF is shown in FIG. The absorption spectrum of the thin film of PCBBiF is shown in FIG. The emission spectrum is shown in FIG. 23(A) and the absorption spectrum is shown in FIG. 23(B). A visible spectrophotometer (V550 model, manufactured by JASCO Corporation) was used. The solution was placed in a quartz cell, The thin film was evaporated onto a quartz substrate to prepare a sample for measurement. For the solution, the absorption spectrum was subtracted from that measured by putting only toluene in a quartz cell. The absorption spectrum of the thin film is shown by subtracting the absorption spectrum of the quartz substrate. 22 and 23, the horizontal axis is wavelength (nm) and the vertical axis is intensity (arbitrary unit). In the case of the toluene solution, an absorption peak is observed around 350 nm, and the emission wavelength peak is The excitation wavelengths were 401 nm and 420 nm (excitation wavelength 360 nm). An absorption peak is observed around 356 nm, and emission wavelength peaks are 415 nm and 436 nm (excitation The excitation wavelength was 370 nm.

[0401] (Reference example 2) The 9,9-dimethyl-N-[4-(1-naphthyl)phenyl]-N-[4 -(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2 This article explains how to synthesize PCBNBF.

[0402] [ka]

[0403] <Step 1: Synthesis of 1-(4-bromophenyl)naphthalene> The synthetic scheme of step 1 is shown in (y-1).

[0404] [ka]

[0405] In a 3L three-neck flask, add 47g (0.28mol) of 1-naphthaleneboronic acid and Add 82 g (0.29 mol) of iodobenzene, 750 mL of toluene, and 2 mL of ethanol. 50 mL of the mixture was added. The mixture was degassed by stirring under reduced pressure. After degassing, the flask was The atmosphere was replaced with nitrogen. 415 mL of potassium carbonate solution (2.0 mol / L) was added to this solution. The mixture was then degassed again by stirring under reduced pressure. After degassing, the flask was filled with nitrogen. To this was added 4.2g (14mmol) of tri(ortho-tolyl)phosphine and acetic acid. Palladium(II), 0.7 g (2.8 mmol), was added. The mixture was stirred for 9 h under a nitrogen stream. The mixture was stirred at 0° C. for 1 hour.

[0406] After stirring, the mixture was allowed to cool to room temperature, and the aqueous layer of the mixture was extracted three times with toluene. The extract and the organic layer were combined and washed twice with water and twice with saturated saline. Magnesium was added and the mixture was left to stand for 18 hours and dried. The nesium was removed and the resulting filtrate was concentrated to give an orange liquid.

[0407] 500 mL of hexane was added to the orange liquid, and the resulting solution was then separated by filtration using Celite, Florisy The filtrate was concentrated to give a colorless liquid. The mixture was allowed to stand at -10°C, and the precipitated impurities were filtered off. The filtrate was concentrated and colorless. A colorless liquid was obtained. The colorless liquid was purified by vacuum distillation, and the resulting yellow liquid was then passed through a silica gel column. When purified by chromatography (eluent: hexane), the target colorless liquid was obtained. The amount was 56 g, with a yield of 72%.

[0408] <Step 2: 9,9-Dimethyl-N-(4-naphthyl)phenyl-N-phenyl-9H -Synthesis of fluorene-2-amine> The synthetic scheme for step 2 is shown in (y-2).

[0409] [ka]

[0410] In a 1L three-neck flask, add 9,9-dimethyl-N-phenyl-9H-fluoren-2-amine. 40g (0.14mol) and 40g (0.42mol) of sodium tert-butoxide ) and 2.8 g (1.4 mmol) of bis(dibenzylideneacetone)palladium(0) Put 44g (0.15mol) of 1-(4-bromophenyl)naphthalene in toluene. The mixture was degassed by stirring under reduced pressure. The atmosphere inside the container was replaced with nitrogen. Then, tri(tert-butyl)phosphine (10 wt% hexafluorophosphate) was added. The mixture was heated at 110°C for 2 hours under a nitrogen stream. The mixture was stirred for 1 hour.

[0411] The mixture was then cooled to room temperature, and the solid was filtered off by suction filtration. The mixture was concentrated to give a dark brown liquid. The dark brown liquid was mixed with toluene, and the resulting solution was The resulting filtrate was concentrated to give a pale yellow solid. This pale yellow liquid was recrystallized with acetonitrile to obtain the target pale yellow powder. The amount was 53 g, with a yield of 78%.

[0412] <Step 3: N-(4-bromophenyl)-9,9-dimethyl-N-[4-(1-naphthalene)- Synthesis of 9H-fluoren-2-amine The synthetic scheme for step 3 is shown in (y-3).

[0413] [ka]

[0414] In a 2 L Mayer flask, add 9,9-dimethyl-N-(4-naphthyl)phenyl-N-phenyl 59 g (0.12 mol) of 9H-fluorenyl-2-amine and 300 mL of toluene The mixture was stirred under heating. The resulting solution was allowed to cool to room temperature and then acetic acid was added. Add 300 mL of ethyl acetate, then add 21 g (0.01 mL) of N-bromosuccinimide (abbreviation: NBS). 1.12 mol) was added and stirred at room temperature for about 2.5 hours. 400 mL of an aqueous thorium solution was added and stirred at room temperature. The organic layer of this mixture was diluted with saturated carbonated water. The mixture was washed twice with an aqueous solution of sodium chloride and twice with saturated saline. The mixture was left to stand for 2 hours and dried. After removing magnesium sulfate by gravity filtration, The filtrate was concentrated to give a yellow liquid. This liquid was dissolved in toluene and then The liquid was purified through Celite, alumina, and Florisil to obtain a pale yellow solid. The yellow solid was reprecipitated using toluene / acetonitrile to obtain the desired white powder. The amount was 56 g, with a yield of 85%.

[0415] <Step 4: Synthesis of PCBNBF> The synthetic scheme for step 4 is shown in (y-4).

[0416] [ka]

[0417] In a 1 L three-neck flask, add N-(4-bromophenyl)-9,9-dimethyl-N-[4-(1 51 g (90 mmol) of 9H-fluoren-2-amine and 28 g (95 mmol) of 1-phenyl-9H-carbazole-3-boronic acid and paradiacetate 0.4 mg (1.8 mmol) of ammonium(II) and 1. 4g (4.5mmol), 300mL of toluene, 100mL of ethanol, and potassium carbonate 135 mL of aqueous ammonium chloride solution (2.0 mol / L) was added. The mixture was stirred under reduced pressure. After degassing, the atmosphere in the flask was replaced with nitrogen. The mixture was stirred at room temperature for 1.5 hours. After stirring, the mixture was cooled to room temperature and the solid was filtered off with suction. The organic layer was removed from the mixture of the aqueous layer and the organic layer and concentrated to obtain a brown solid. This brown solid was recrystallized using toluene / ethyl acetate / ethanol to obtain the desired white solid. The solid recovered after stirring was mixed with the white powder obtained by recrystallization. After dissolving in toluene, it was purified through Celite, alumina, and Florisil. The resulting solution was concentrated and recrystallized from toluene / ethanol to obtain the desired white powder. The product was obtained in an amount of 54 g and a yield of 82%.

[0418] The resulting white powder (51 g) was purified by train sublimation. The white powder was heated to 360°C under the conditions of 3.7 Pa pressure and 15 mL / min argon flow rate. After purification by sublimation, the target pale yellow solid was obtained in a yield of 19 g and a recovery rate of 38%.

[0419] Nuclear magnetic resonance (NMR) analysis confirmed that this compound was the target compound, 9,9-dimethyl-N-[ 4-(1-naphthyl)phenyl]-N-[4-(9-phenyl-9H-carbazole-3 -yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBNBF) confirmed.

[0420] The obtained material 1 The 1 H NMR data is shown below. 1 H NMR (CDCl 3 ,500MHz):δ=1.50(s, 6H), 7.21( dd, J=8.0Hz, 1.6Hz, 1H), 7.26-7.38(m, 8H), 7.4 1-7.44(m, 5H), 7.46-7.55(m, 6H), 7.59-7.69(m , 9H), 7.85(d, J=8.0Hz, 1H), 7.91(dd, J=7.5Hz, 1.7Hz, 1H), 8.07-8.09(m, 1H), 8.19(d, J=8.0Hz , 1H), 8.37(d, J=1.7Hz, 1H).

[0421] (Reference example 3) The N-(1,1'-biphenyl-4-yl) compound represented by the following structural formula (119) used in Example 3 was 4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9,9 Synthesis method of '-spirobi[9H-fluorene]-2-amine (abbreviation: PCBBiSF) We will explain about this.

[0422] [ka]

[0423] <Step 1: N-(1,1'-biphenyl-4-yl)-N-phenyl-9,9'-sulfonyl Synthesis of pyrobi[9H-fluorene]-2-amine> The synthetic scheme of step 1 is shown in (z-1).

[0424] [ka]

[0425] In a 200 mL three-neck flask, add 4.8 mL of 2-bromo-9,9-spirobi[9H-fluorene] g (12 mmol), 3.0 g (12 mmol) of 4-phenyl-diphenylamine, Add 3.5g (37mmol) of sodium tert-butoxide and place the flask under nitrogen. To this mixture, 60 mL of dehydrated toluene and tri(tert-butyl)phosphine ( Add 0.2 mL of a 10% hexane solution and degas the mixture by stirring under reduced pressure. To this mixture was added 70 mg (0. The mixture was heated and stirred at 110°C for 8 hours under a nitrogen stream. Water was added to the mixture, the aqueous layer was extracted with toluene, and the extract and the organic layer were combined and washed with saturated saline. The organic layer was dried over magnesium sulfate. The mixture was separated by gravity filtration. The filtrate was concentrated to give a solid.

[0426] This solid was purified by silica gel column chromatography. The developing solvent was toluene:hexane = 1:5, then toluene:hexane = 1:3. The obtained fraction was concentrated to give a solid. The obtained solid was dissolved in toluene / ethyl acetate. Recrystallization gave a white solid, 5.7 g, yield 83%.

[0427] <Step 2: N-(1,1'-biphenyl-4-yl)-N-(4-bromophenyl) -Synthesis of 9,9'-spirobi[9H-fluorene]-2-amine> The synthetic scheme of step 2 is shown in (z-2).

[0428] [ka]

[0429] In a 100 mL three-neck flask, add N-(1,1'-biphenyl-4-yl)-N-phenyl- 3.0 g (5.4 mmol) of 9,9'-spirobi[9H-fluorene]-2-amine, 20 mL of toluene and 40 mL of ethyl acetate were added. ol) of N-bromosuccinimide (abbreviation: NBS) was added and stirred for 25 hours. The mixture was washed with water and a saturated aqueous solution of sodium bicarbonate, and the organic layer was then extracted with magnesium sulfate. The mixture was separated by gravity filtration, and the filtrate was concentrated to obtain a solid. The solid was purified by silica gel column chromatography. The developing solvent was hexane, followed by toluene:hexane = 1:5, and the obtained fractions The mixture was concentrated to give a solid. The solid was recrystallized from ethyl acetate / hexane to give a white solid. The amount was 2.8 g, with a yield of 83%.

[0430] <Step 3: Synthesis of PCBBiSF> The synthetic scheme of step 3 is shown in (z-3).

[0431] [ka]

[0432] In a 200 mL three-neck flask, add N-(1,1'-biphenyl-4-yl)-N-(4-bromo 2.4g (3.8 mophenyl)-9,9'-spirobi[9H-fluorene]-2-amine mmol) and 1.3 g (4.5 mmol) of 9-phenylcarbazole-3-boronic acid 57 mg (0.19 mmol) of tri(o-tolyl)phosphine and 1 mg of potassium carbonate 0.2g (9.0mmol) was added to the mixture. 5mL of water, 14mL of toluene, 7 mL of ethanol was added and the mixture was degassed by stirring under reduced pressure. The mixture was stirred at 90°C for 7.5 hours under a nitrogen stream. After stirring, the resulting mixture was extracted with toluene. The resulting extract solution and the organic layer were combined, After washing with saturated saline, the mixture was dried over magnesium sulfate. The filtrate was concentrated to give a solid. This solid was purified by silica gel column chromatography. The column chromatography was carried out using toluene:hexane = 1:2, then toluene:hexane = 1:2. The developing solvent was hexane = 2:3, and the obtained fraction was concentrated to obtain a solid. The solid was recrystallized from ethyl acetate / hexane to obtain the desired white solid (2.8 g, 94% yield). I got it at.

[0433] The obtained solid (2.8 g) was purified by train sublimation at a pressure of 2.9 P. a, Argon flow rate 5mL / min, heating at 336℃. A yellow solid was obtained in a yield of 0.99 g and a recovery rate of 35%.

[0434] Nuclear magnetic resonance (NMR) analysis confirmed that this compound was the target N-(1,1'-biphenyl) -N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl ]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBBiSF) I confirmed that there is.

[0435] The pale yellow solid obtained 1 The 1 H NMR data is shown below. 1 H NMR (CDCl 3 ,500MHz):δ=6.67-6.69(m, 2H), 6.84(d, J1=7.5Hz, 2H), 7.04-7.11(m, 5H), 7.13 -7.17(m, 3H), 7.28-7.45(m, 12H), 7.46-7.53(m , 5H), 7.57-7.64(m, 5H), 7.74-7.77(m, 4H), 8.1 7(d, J1=7.5Hz, 1H), 8.27(d, J1=1.5Hz, 1H).

[0436] Also, 1 The H NMR chart is shown in FIG. 24. Note that FIG. 24(B) shows the same H NMR chart as FIG. 24(A). This is an expanded chart showing the range of 6.50 ppm to 8.50 ppm.

[0437] The absorption spectrum of the PCBBiSF toluene solution is shown in Figure 25(A), and the emission spectrum is shown in Figure 25(B). The absorption spectrum of the thin film of PCBBiSF is shown in Fig. 25(B). The absorption spectrum is shown in FIG. 6(A) and the emission spectrum is shown in FIG. 26(B). The values ​​are the same as those in Reference Example 1. In FIG. 25 and FIG. 26, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity ( In the case of a toluene solution, an absorption peak is observed around 352 nm, and an emission The wavelength peak was 403 nm (excitation wavelength 351 nm). The absorption peak is observed around 57 nm, and the emission wavelength peak is 424 nm (excitation wavelength 378 nm). m). [Explanation of symbols]

[0438] 201 First electrode 203 EL layer 203a First EL layer 203b Second EL layer 205 Second electrode 207 Middle Class 213 Light-emitting layer 221 The first organic compound 222 Second organic compound 223 Phosphorescent compounds 301 Hole injection layer 302 Hole transport layer 303 Light-emitting layer 304 Electron transport layer 305 Electron injection layer 306 Electron injection buffer layer 307 Electronic Relay Layer 308 Charge generation area 401 Support substrate 403 Light emitting element 405 Sealing substrate 407 Sealing material 409a First Terminal 409b Second Terminal 411a Light extraction structure 411b Light extraction structure 413 Planarization layer 415 Space 417 Auxiliary wiring 419 Insulating Layer 421 First electrode 423 EL layer 425 Second Electrode 501 Support substrate 503 Light emitting element 505 Sealing substrate 507 Sealing material 509 FPC 511 Insulating layer 513 Insulating Layer 515 Space 517 Wiring 519 Bulkhead 521 First electrode 523 EL layer 525 Second Electrode 531 Black Matrix 533 Color Filter 535 Overcoat layer 541a Transistor 541b Transistor 542 Transistor 543 Transistor 551 Light emitting part 552 Drive circuit section 553 Drive circuit section 1100 Glass substrate 1101 First electrode 1103 Second electrode 1111 Hole injection layer 1112 Hole transport layer 1113 Light-emitting layer 1114 Electron transport layer 1115 Electron injection layer 7100 Television equipment 7101 Case 7102 Display section 7103 Stand 7111 Remote control device 7200 Computer 7201 Main unit 7202 Case 7203 Display section 7204 Keyboard 7205 External connection port 7206 Pointing Device 7300 Portable Game Console 7301a Housing 7301b Case 7302 Connection section 7303a Display section 7303b Display section 7304 Speaker section 7305 Recording medium insertion section 7306 Operation key 7307 Connection terminal 7308 Sensor 7400 Mobile Phone 7401 Case 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Mike 7500 Tablet PC 7501a Case 7501b Case 7502a Display section 7502b Display section 7503 Shaft 7504 Power supply 7505 Operation key 7506 Speaker 7601 Lighting Department 7602 Umbrella 7603 Variable Arm 7604 Post 7605 units 7606 Power supply 7701 Lighting equipment 7702 Lighting equipment 7703 Table lamp

Claims

[Claim 1] A light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a first organic compound, a second organic compound, and a phosphorescent compound; the first organic compound and the second organic compound are a combination that forms an exciplex, a difference between an energy value of a peak in an emission spectrum of the exciplex and an energy value of a peak in an absorption band on the lowest energy side of the phosphorescent compound is within 0.2 eV; A compound represented by formula (G0) is contained between the anode and the light-emitting layer, a layer containing the compound represented by formula (G0) is in contact with the light-emitting layer; 【Chemistry 1】 (In formula (G0), Ar １ and Ar ２ each independently represents a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted biphenyl group; Ar ３ represents a substituent containing a carbazole skeleton.

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