Fluorene derivatives, light-emitting elements, light-emitting devices, electronic devices, and lighting devices

Abstract

An object of the present invention is to provide a light-emitting element having high luminous efficiency by using a novel fluorene derivative represented by the following general formula (G1). In the formula, R<supgt;1< / supgt> to R<supgt;8< / supgt> independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted biphenyl group. Further, α<supgt;1< / supgt> to α<supgt;4< / supgt> independently represent any one of a substituted or unsubstituted arylene group having 6 to 12 carbon atoms. Further, Ar1 and Ar2 independently represent any one of an aryl group having 6 to 13 ring carbon atoms, and Ar<supgt;3 represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. J, k, m, and n independently represent 0 or 1.

Description

[0001] This application is a divisional application of PCT patent application with international application number PCT / JP2010 / 058854 filed on May 19, 2010, China national phase application number 201080025006.4, and invention title "Fluorene Derivative, Light-Emitting Element, Light-Emitting Device, Electronic Device, and Lighting Device". This application claims the priority of May 29, 2009. Technical Field

[0002] The present invention relates to a fluorene derivative, a light-emitting element, a light-emitting device, an electronic device, and a lighting device. Background Art

[0003] In recent years, intensive research and development have been carried out on light-emitting elements utilizing electroluminescence. In the basic structure of such a light-emitting element, a layer containing a substance having a light-emitting property is inserted between a pair of electrodes. By applying a voltage to this element, light emission can be obtained from the substance having a light-emitting property.

[0004] Since such light-emitting elements are of the self-luminous type, it is considered that the advantages of such light-emitting elements compared with liquid crystal displays are high pixel visibility and the absence of a backlight, etc., and thus they are suitable as flat panel display elements. In addition, such light-emitting elements have the advantages that they can form thin and light elements and have an extremely fast response speed.

[0005] Moreover, since such light-emitting elements can be formed into a film shape, planar light emission can be easily obtained. Therefore, a large-area element utilizing planar light emission can be formed. This is a characteristic that is difficult to obtain with point light sources represented by incandescent lamps and LEDs or line light sources represented by fluorescent lamps. Therefore, the light-emitting element is particularly effective as a surface light source for uses such as lighting.

[0006] Light-emitting elements utilizing electroluminescence properties can be generally classified according to whether an organic compound or an inorganic compound is used as a light-emitting substance. When an organic compound is used as a light-emitting substance, by applying a voltage to the light-emitting element, electrons and holes can be injected from a pair of electrodes into the layer containing the light-emitting organic compound, thereby generating a current. When carriers (electrons and holes) recombine and the electrons and holes of the organic compound return from the excited state to the ground state, light is emitted, where electrons and holes are simultaneously generated in the organic molecules having a light-emitting property.

[0007] According to this mechanism, such a light-emitting element is called a current-excited light-emitting element. It should be noted that the excited state generated by the organic compound can be a singlet excited state or a triplet excited state, and the light emitted from the singlet excited state is called fluorescence, and the light emitted from the triplet excited state is called phosphorescence.

[0008] In addition to the above-mentioned light emission by recombining carriers excited by current, there is also a method of transferring excitation energy to another organic compound to excite the organic compound to provide light emission. In this element structure, a light-emitting material is diffused (doped) into the light-emitting layer of a common organic EL. The host material refers to the material into which the light-emitting material is diffused, and the dopant refers to the material diffused into the host material. In order to solve the problem that when the concentration of organic molecules is high (concentration quenching) in organic molecules, due to the occurrence of stacking interactions, the light-emitting efficiency of the provided light emission is low, it is beneficial to obtain high luminous efficiency by doping organic molecules into the host material and suppressing stacking. At the same time, the excitation energy excited by current is transferred from the host material excited by current to the dopant, so that the dopant emits light.

[0009] This excitation energy transfer occurs only when the high excitation energy transfers to the low excitation energy. Therefore, it is preferable to use a material with a high excited state as the host material.

[0010] The organic EL layer has multiple layers, and a carrier transport layer is usually provided between the light-emitting layer and the electrode. One of the reasons is that the carrier transport layer can prevent the quenching of the excitation energy in the light-emitting layer due to the energy transfer to the electrode. In addition, a material with an excitation energy higher than that of the light-emitting layer (exciton blocking material) is preferably used for the carrier transport layer adjacent to the light-emitting layer, so that the excitation energy in the light-emitting layer does not transfer.

[0011] Another reason for providing a carrier injection layer and a carrier transport layer between the light-emitting layer and the electrode of the organic EL is to adjust the carrier injection distribution between adjacent layers. Accordingly, recombination can be effectively carried out in the light-emitting layer.

[0012] In the process of improving the element characteristics of such a light-emitting element, there are many problems depending on the substance. In order to solve these problems, improvements have been made to the element structure, substance research and development, etc. (for example, see Patent Document 1).

[0013] [References]

[0014] [Patent Documents]

[0015] [Patent Document 1] PCT International Publication No. 08 / 062636 Summary of the Invention

[0016] An object of an embodiment of the present invention is to provide a new fluorene derivative as a substance having a high hole-transporting property. Another object is to provide a light-emitting element having a high luminous efficiency by applying the new fluorene derivative to a light-emitting element. Another object of an embodiment of the present invention is to provide a light-emitting device, an electronic device, and a lighting device each having low power consumption and a low driving voltage.

[0017] One embodiment of the present invention is a fluorene derivative represented by the following general formula (G1):

[0018] [Chemical formula 1]

[0019]

[0020] In the formula, R 1 -R 8 independently represents any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted biphenyl group. In addition, α 1 -α 4 independently represents any one of a substituted or unsubstituted arylene group having 6 to 12 carbon atoms. In addition, Ar 1 and Ar 2 independently represent any one of an aryl group having 6 to 13 ring carbon atoms, and Ar 3 represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. J, k, m, and n independently represent 0 or 1. It should be noted that at least one of J and k is 1.

[0021] In the above structure, R 1 -R 8 in the general formula (G1) independently represents any one of the structural formulas (R-1) to (R-9).

[0022] [Chemical formula 2]

[0023]

[0024] In the above structure, α 1 -α 4 in the general formula (G1) independently represents any one of the structural formulas (α-1) to (α-3).

[0025] [Chemical formula 3]

[0026]

[0027] In the above structure, Ar 1 and Ar 2 in the general formula (G1) independently represent any one of the structural formulas (Ar-1) to (Ar-6), and Ar 3 represents any one of the structural formulas (Ar3-1) to (Ar3-8).

[0028] [Chemical formula 4]

[0029]

[0030] [Chemical formula 5]

[0031]

[0032] Another embodiment of the present invention is represented by the following structural formula (101), structural formula (151), or structural formula (118).

[0033] [Chemical formula 6]

[0034]

[0035] [Chemical formula 7]

[0036]

[0037] [Chemical formula 8]

[0038]

[0039] In addition, another embodiment of the present invention is a light-emitting element including an EL layer located between a pair of electrodes. The EL layer includes at least a light-emitting layer and a hole transport layer, and the hole transport layer includes one or more of the above-mentioned fluorene derivatives.

[0040] In addition, another embodiment of the present invention is a light-emitting device formed using the above light-emitting element. Another embodiment of the present invention is an electronic device formed using the above light-emitting device. Another embodiment of the present invention is an illumination device formed using the above light-emitting device.

[0041] A light-emitting device according to an embodiment of the present invention is a light-emitting device including the aforementioned light-emitting element and a control device that controls light emission in the light-emitting element. It should be noted that the light-emitting device described in this specification includes an image display device, a light-emitting device, or a light source (including an illumination device). In addition, the light-emitting device includes any module among all the following modules: a module in which a connector (such as a flexible printed circuit (FPC), a tape automated bonding (TAB) tape, or a tape carrier package (TCP)) is connected to a board; a module in which a printed circuit board is assembled at the end of a TAB tape or a TCP; an integrated circuit (IC) module including a direct mounting on a light-emitting element by a chip on glass (COG) method.

[0042] In addition, an electronic device for a display part in an embodiment of the light-emitting device of the present invention is also included within the scope of the present invention. Therefore, an embodiment of the electronic device of the present invention includes a display part, and the display part is provided with the above light-emitting device.

[0043] In addition, an illumination device using an embodiment of the light-emitting device of the present invention is also included within the scope of the present invention. Therefore, an embodiment of the illumination device of the present invention is provided with the above light-emitting device.

[0044] Since the fluorene derivative of the present invention has high hole transportability, it can be mainly used for the hole transport layer in the EL layer of a light-emitting element. In addition, the fluorene derivative of the present invention is used in the hole transport layer to form a light-emitting element, thereby a light-emitting element with high luminous efficiency can be formed.

[0045] Meanwhile, by using such a light-emitting element, a light-emitting device, an electronic device, and a lighting device with low power consumption and low driving voltage can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1A and 1B each is a diagram showing a light-emitting element;

[0047] Figures 2A - 2C each is a diagram showing a light-emitting element;

[0048] Figure 3A and 3B each is a diagram showing a light-emitting element;

[0049] Figure 4A and 4B each is a diagram showing a light-emitting device;

[0050] Figure 5A and 5B each is a diagram showing a light-emitting device;

[0051] Figures 6A - 6D is a diagram showing an electronic device;

[0052] Figure 7 is a diagram showing an electronic device;

[0053] Figure 8 is a diagram showing a lighting device;

[0054] Figure 9 is a diagram showing a lighting device;

[0055] Figure 10A and 10B is the 1 1H-NMR spectrum of 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine;

[0056] Figure 11 is the absorption spectrum of 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine;

[0057] Figure 12 is the emission spectrum of 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine;

[0058] Figure 13It is a figure showing the CV test results of 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine;

[0059] Figure 14A and 14B is of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine 1 1H-NMR spectrum;

[0060] Figure 15 is the absorption spectrum of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine;

[0061] Figure 16 is the emission spectrum of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine;

[0062] Figure 17 is a figure showing the CV test results of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine;

[0063] Figure 18 is a figure showing the light-emitting element in the examples.

[0064] Figure 19 is a characteristic figure showing the current density and luminance of Comparative Light-Emitting Element 1 and Light-Emitting Element 2.

[0065] Figure 20 is a characteristic figure showing the voltage and luminance of Comparative Light-Emitting Element 1 and Light-Emitting Element 2.

[0066] Figure 21 is a characteristic figure showing the luminance and current efficiency of Comparative Light-Emitting Element 1 and Light-Emitting Element 2.

[0067] Figure 22 is a characteristic figure showing the current density and luminance of Light-Emitting Element 3;

[0068] Figure 23 is a characteristic figure showing the voltage and luminance of Light-Emitting Element 3;

[0069] Figure 24 is a characteristic figure showing the luminance and current efficiency of Light-Emitting Element 3;

[0070] Figure 25 is a figure showing the reliability test results of Light-Emitting Element 3;

[0071] Figure 26 is a characteristic figure showing the current density and luminance of Light-Emitting Element 4 and Light-Emitting Element 5;

[0072] Figure 27 is a characteristic figure showing the voltage and luminance of Light-Emitting Element 4 and Light-Emitting Element 5;

[0073] Figure 28 is a characteristic diagram showing the brightness and current efficiency of light-emitting element 4 and light-emitting element 5;

[0074] Figure 29 is a diagram showing the reliability test results of light-emitting element 4 and light-emitting element 5;

[0075] Figure 30 is a characteristic diagram showing the current density and brightness of light-emitting element 6 and comparative light-emitting element 7;

[0076] Figure 31 is a characteristic diagram showing the voltage and brightness of light-emitting element 6 and comparative light-emitting element 7.

[0077] Figure 32 is a characteristic diagram showing the brightness and current efficiency of light-emitting element 6 and comparative light-emitting element 7;

[0078] Figure 33 is a diagram showing the emission spectra of light-emitting element 6 and comparative light-emitting element 7;

[0079] Figure 34 is a characteristic diagram showing the current density and brightness of light-emitting elements 8 to 10;

[0080] Figure 35 is a characteristic diagram showing the voltage and brightness of light-emitting elements 8 to 10;

[0081] Figure 36 is a characteristic diagram showing the brightness and current efficiency of light-emitting elements 8 to 10;

[0082] Figure 37 is a diagram showing the reliability test results of light-emitting elements 8 to 10;

[0083] Figure 38 is a characteristic diagram showing the current density and brightness of light-emitting element 11 and comparative light-emitting element 12;

[0084] Figure 39 is a characteristic diagram showing the voltage and brightness of light-emitting element 11 and comparative light-emitting element 12;

[0085] Figure 40 is a characteristic diagram showing the brightness and current efficiency of light-emitting element 11 and comparative light-emitting element 12;

[0086] Figure 41 is a diagram showing the emission spectra of light-emitting element 11 and comparative light-emitting element 12;

[0087] Figure 42 is a characteristic diagram showing the current density and brightness of light-emitting element 13;

[0088] Figure 43 is a characteristic diagram showing the voltage and luminance of the light-emitting element 13;

[0089] Figure 44 is a characteristic diagram showing the luminance and current efficiency of the light-emitting element 13;

[0090] Figure 45A and 45B is the 1 1H-NMR spectrum of 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine;

[0091] Figure 46 is a diagram showing the absorption spectrum of 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine;

[0092] Figure 47 is a diagram showing the emission spectrum of 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine;

[0093] Figure 48 is a characteristic diagram showing the current density and luminance of the light-emitting element 14 and the comparative light-emitting element 15;

[0094] Figure 49 is a characteristic diagram showing the voltage and luminance of the light-emitting element 14 and the comparative light-emitting element 15;

[0095] Figure 50 is a characteristic diagram showing the luminance and current efficiency of the light-emitting element 14 and the comparative light-emitting element 15;

[0096] Best Mode of the Present Invention

[0097] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the present invention is not limited to the following description, and those skilled in the art can easily understand that various changes and improvements can be made without departing from the purpose and scope of the present invention. Therefore, the present invention is not limited to the following description in the embodiments.

[0098] (Embodiment 1)

[0099] In Embodiment 1, a fluorene derivative according to an embodiment of the present invention is described.

[0100] A fluorene derivative according to an embodiment of the present invention is a fluorene derivative represented by the general formula (G1).

[0101] [Chemical Formula 9]

[0102]

[0103] In the formula, R 1 -R 8Independently represents any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted biphenyl group. Further, α 1 -α 4 Independently represents any one of a substituted or unsubstituted arylene group having 6 to 12 carbon atoms. Further, Ar 1 and Ar 2 Independently represents any one of an aryl group having 6 to 13 ring carbon atoms, Ar 3 represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. J, k, m, and n independently represent 0 or 1. It should be noted that at least one of J and k is 1.

[0104] When R 1 -R 8 , α 1 to α 4 , Ar 1 , Ar 2 , Ar 3 has a substituent, examples of the substituent may be an alkyl group such as methyl, ethyl, propyl, pentyl or hexyl, or an aryl group such as phenyl or biphenyl. Alternatively, the substituents may be connected to each other to form a ring (for example, the biphenyl group forms a ring with the fluorene group of Ar 1 or Ar 2 to form a 9,9′-spirofluorene group), or hexyl forms a ring (to form a cyclohexyl group).

[0105] It is considered that when an alkyl group is used in the general formula (G1), the solubility in an organic solvent is improved; therefore, when using this material to form an element by a wet process, it is preferable to use a material having an alkyl group to easily manufacture the element.

[0106] For R 1 to R 8 in the general formula (G1), it may be a hydrogen atom, an alkyl group such as methyl, ethyl, propyl, pentyl or hexyl, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted aryl group such as biphenyl. Specific structural formulas (R-1) to (R-9) are given.

[0107] [Chemical formula 10]

[0108]

[0109] For α 1 to α 4 in the general formula (G1), it may be a substituted or unsubstituted phenylene group. Specific structural formulas (α-1) to (α-3) are given.

[0110] [Chemical formula 11]

[0111]

[0112] For Ar in the general formula (G1) 1 and Ar 2 , it may be a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, or a substituted or unsubstituted aryl group such as a spirofluorenyl group. Specific structural formulas (Ar-1) to (Ar-6) are given. In (Ar-4) shown below, the biphenyl group and the fluorenyl group of Ar 1 or Ar 2 form a ring, that is, 9,9'-spirofluorenyl group.

[0113] In this case, when using the condensed ring group shown by (Ar-2) or (Ar-3), the carrier transport performance is improved, which is preferred. Also in this case, when α 1 or α 2 between the condensed ring group and the nitrogen atom is 1, the molecule can maintain a relatively wide band gap (Bg), which is preferred. In addition, as shown by (Ar-5), the structure bonded by a σ bond makes the conjugation from the nitrogen atom difficult to extend, and Bg and T1 energy levels are high. Therefore, it is considered that this material can be used as a layer material adjacent to the light-emitting layer or as a doping material for the light-emitting layer in a light-emitting element with a shorter wavelength, which is preferred. Additionally, when using a condensed ring group with a large and rigid molecular weight such as (Ar-2), (Ar-3) or (Ar-4), the thermophysical properties such as the glass transition temperature (T g ) are improved, which is preferred.

[0114] [Chemical formula 12]

[0115]

[0116] For Ar in the general formula (G1) 3 , it may be an alkyl group such as methyl, ethyl, propyl, pentyl or hexyl, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted aryl group such as biphenyl. Specific structural formulas (Ar3-1) to (Ar3-8) are given.

[0117] [Chemical formula 13]

[0118]

[0119] Fluorene derivatives represented by structural formulas (100) to (123) or structural formulas (150) to (173) are given as specific examples of the fluorene derivatives represented by the general formula (G1). However, the embodiments of the present invention are not limited thereto.

[0120] [Chemical formula 14]

[0121]

[0122] [Chemical Formula 15]

[0123]

[0124] [Chemical Formula 16]

[0125]

[0126] [Chemical Formula 17]

[0127]

[0128] [Chemical Formula 18]

[0129]

[0130] [Chemical Formula 19]

[0131]

[0132] [Chemical Formula 20]

[0133]

[0134] [Chemical Formula 21]

[0135]

[0136] Various reactions can be applied to the synthesis method of the fluorene derivatives according to the embodiments of the present invention. For example, the fluorene derivatives represented by the general formula (G1) in the embodiments of the present invention can be synthesized through the synthesis reactions described below. It should be noted that the synthesis method of the fluorene derivatives in the embodiments of the present invention is not limited to the following synthesis methods.

[0137] <Synthesis Method 1 of the Fluorene Derivative Represented by the General Formula (G1)>

[0138] As shown in Scheme (A-1), a 1-halobiphenyl derivative (a1) is lithiated or made into a Grignard reagent, and reacted with a benzoyl derivative (a2) for dehydroxylation to obtain a haloarylfluorene derivative (a3).

[0139] [Chemical Formula 22]

[0140]

[0141] The aryl compound containing a halogen in Scheme (A-1) is activated, reacted with a benzoyl derivative to form a phenol derivative, and dehydroxylated through acid addition, thereby a fluorene derivative can be obtained.

[0142] Lithiation reactions using alkyl lithium reagents or reactions using active magnesium to obtain Grignard reagents can be used as examples of activation. n-Butyl lithium, tert-butyl lithium, and methyl lithium are examples of alkyl lithiums. Hydrochloric acid can be used as an acid. Ethers such as diethyl ether, or tetrahydrofuran (THF) can be used as dehydration solvents.

[0143] As shown in Scheme (A-2), a diarylamine derivative (a6) can be obtained by coupling a halogenated aromatic hydrocarbon derivative (a4) and an arylamine derivative (a5).

[0144] [Chemical formula 23]

[0145]

[0146] As shown in Scheme (A-3), a fluorene derivative represented by the above general formula (G1) can be obtained by coupling a halogenated arylfluorene derivative (a3) ​​and a diarylamine derivative (a6).

[0147] [Chemical formula 24]

[0148]

[0149] It should be noted that X in the above schemes (A-1) to (A-3) 1 ,X 2 or X 3 is a halogen, preferably bromine or iodine, more preferably iodine due to high reactivity.

[0150] In schemes (A-2) and (A-3), there are various reaction conditions for the coupling reaction of an aryl compound containing a halogen group and an aryl compound containing an amine (aryl primary amine compound or aryl secondary amine compound). As an example, a synthesis method using a metal catalyst in the presence of a base can be used.

[0151] The case of performing the Buchwald-Hartwig reaction in schemes (A-2) and (A-3) is shown. A palladium catalyst can be used as a metal catalyst, and a mixture of a palladium complex and its ligand can be used as a palladium catalyst. Examples of palladium catalysts such as di(dibenzylideneacetone)palladium(0) and palladium acetate(II) are given. Tri-tert-butylphosphine, tri-n-hexylphosphine, tricyclohexylphosphine, 1,1-bis(diphenylphosphino)ferrocene (abbreviation: DPPF) and the like are given as ligands. Organic bases such as sodium tert-butoxide and inorganic bases such as potassium carbonate are given as substances that can be used as bases. In addition, the above reaction is preferably carried out in a solution, and toluene, xylene and benzene and the like can be used as solvents in the above reaction. However, the catalysts, ligands, bases and solvents that can be used are not limited thereto. In addition, the reaction is preferably carried out under an inert atmosphere such as nitrogen and argon.

[0152] Illustrates the case of carrying out the Ullmann reaction in Schemes (A-2) and (A-3). A copper catalyst can be used as the metal catalyst, and cuprous iodide (I) and copper acetate (II) are given as examples of the copper catalyst. An inorganic base such as potassium carbonate is given as an example of a substance that can be used as the base. The above reaction is preferably carried out in a solution, and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (abbreviation: DMPU), toluene, xylene, benzene, etc. are given as solvents that can be used in the above reaction. However, the catalysts, ligands, bases, and solvents that can be used are not limited to these. In addition, the reaction is preferably carried out in an inert atmosphere such as nitrogen or argon.

[0153] It should be noted that it is preferable to use a high-boiling solvent such as DMPU or xylene, because when the reaction temperature is higher than or equal to 100 °C, the target substance can be obtained in a shorter time and with a higher yield through the Ullmann reaction. Specifically, since the reaction temperature is more preferably higher than or equal to 150 °C, DMPU is more preferred.

[0154] <Synthesis method 2 of fluorene derivatives represented by general formula (G1)>

[0155] For example, as shown in Scheme (B-1), a haloaryl fluorene derivative (a3) and an arylamine derivative (a5) are coupled to obtain a diarylamine derivative having a fluorenyl group (b1).

[0156] [Chemical formula 25]

[0157]

[0158] As shown in Scheme (B-2), a diarylamine derivative (b1) containing a fluorenyl group and a haloarene derivative (a4) are coupled to obtain the fluorene derivative represented by the above general formula (G1).

[0159] [Chemical formula 26]

[0160]

[0161] It should be noted that X in the above Schemes (B-1) and (B-2) 2 or X 3 is a halogen, preferably bromine or iodine, and iodine is more preferred due to its high reactivity.

[0162] In Schemes (B-1) and (B-2)+, there are various reaction conditions for the coupling reaction of an aryl compound containing a halogen group and an aryl compound containing an amine (aryl primary amine compound or aryl secondary amine compound). As an example, a synthesis method using a metal catalyst in the presence of a base can be adopted.

[0163] The Buchwald-Hartwig reaction and the Ullmann reaction can be carried out in a manner similar to that of Schemes (A-2) and (A-3) in Schemes (B-1) and (B-2).

[0164] <Synthesis method 3 of fluorene derivatives represented by general formula (G1)>

[0165] For example, as shown in Scheme (C-1), a haloarylfluorene derivative (c1) is lithiated or converted into a Grignard reagent and reacted with an organoboric acid, whereby an arylboronic acid derivative (c2) having a fluorenyl group can be obtained (note that J represents 1).

[0166] [Chemical formula 27]

[0167]

[0168] As shown in Scheme (C-2), a triarylamine derivative (c3) is halogenated, whereby a halotriarylamine derivative (c4) can be obtained.

[0169] [Chemical formula 28]

[0170]

[0171] As shown in Scheme (C-3), the arylboronic acid derivative (c2) containing a fluorenyl group and the halotriarylamine derivative (c4) are coupled, whereby the fluorene derivative represented by the above general formula (G1) can be obtained.

[0172] [Chemical formula 29]

[0173]

[0174] Note that k represents 1 in Schemes (C-2) and (C-3).

[0175] X in the above Schemes (C-1) to (C-3) 4 or X 5 is a halogen, preferably bromine or iodine, and more preferably iodine due to its high reactivity.

[0176] The reaction of obtaining an aryl compound containing a boric acid group (or an organoboron group) by using an aryl compound containing a halogen group in Scheme (C-1) has various reaction conditions. R in the scheme 1 to R 8 represent hydrogen or an alkyl group.

[0177] As an example of the reaction, after lithiating an aryl compound containing a halogen group using an alkyllithium reagent, a boron reagent is added to effect borylation or organoboration of the aryl compound containing a halogen group. Butyllithium or methyllithium etc. can be used as the alkyllithium reagent. Trimethyl borate or isopropyl borate etc. can be used as the boron reagent. An ether such as diethyl ether, or tetrahydrofuran (THF) can be used as the dehydrating solvent. Alternatively, a Grignard reagent having active magnesium can be used instead of the lithiating reagent.

[0178] The halogenation reaction in Scheme (C-2) has a variety of reaction conditions. For example, a reaction using a halogenating agent in the presence of a polar solvent can be employed. N-bromosuccinimide (abbreviation: NBS), N-iodosuccinimide (abbreviation: NIS), bromine, iodine, potassium iodide, etc. can be used as the halogenating agent. Bromine is preferably used as the halogenating agent since synthesis can be carried out at low cost. Iodine is preferably used as the halogenating agent since the reaction can proceed more easily when the substance generated is used as a source in the subsequent reaction (the part substituted with iodine has higher activity). It should be noted that in Scheme (C-2), k is 1 and the halogenation reaction specifically occurs at the para position of the amine.

[0179] The coupling reaction of an aryl compound containing a halogen group and an aryl compound containing boric acid (arylboronic acid) in Scheme (C-3) has a variety of reaction conditions. As an example, a synthesis method using a metal catalyst in the presence of a base can be employed.

[0180] In Scheme (C-3), the case of employing the Suzuki-Miyaura reaction is described. A palladium catalyst such as a mixture of a palladium complex and its ligand can be used as the metal catalyst. Palladium(II) acetate, tetrakis(triphenylphosphine)palladium(0), and bis(triphenylphosphine)palladium(II) dichloride etc. are given as palladium catalysts. Tri(o-tolyl)phosphine, triphenylphosphine, and tricyclohexylphosphine etc. are given as ligands. In addition, an organic base such as sodium tert-butoxide and an inorganic base such as potassium carbonate etc. are given as bases. The reaction is preferably carried out in a solution, and a mixed solvent of toluene and water; a mixed solvent of toluene, an alcohol such as ethanol and water; a mixed solvent of xylene and water; a mixed solvent of xylene, an alcohol such as ethanol and water; a mixed solvent of benzene and water; a mixed solvent of benzene, an alcohol such as ethanol and water; a mixed solvent of an ether such as ethylene glycol dimethyl ether and water etc. can be used as the solvent. However, the catalysts, ligands, bases, and solvents that can be used are not limited to these. Alternatively, an organoboron compound of an aryl derivative, arylaluminum, arylzirconium, arylzinc, or aryltin compound can be used instead of arylboronic acid in the said scheme. In addition, this reaction is preferably carried out under an inert atmosphere such as nitrogen or argon.

[0181] (Embodiment 2)

[0182] In Embodiment 2, a light-emitting device is described in which the fluorene derivative of the embodiment of the present invention described in Embodiment 1 is used for forming a hole transport layer.

[0183] The light-emitting device of Embodiment 2 includes a first electrode serving as an anode, a second electrode serving as a cathode, and an EL layer disposed between the first electrode and the second electrode. It should be noted that when a voltage is applied across the electrodes such that the potential of the first electrode is higher than that of the second electrode, the light-emitting device of Embodiment 2 can emit light.

[0184] In addition, the EL layer of the light-emitting device of Embodiment 2 includes, from the first electrode side, a first layer (hole injection layer), a second layer (hole transport layer), a third layer (light-emitting layer), a fourth layer (electron transport layer), and a fifth layer (electron injection layer).

[0185] Combined Figure 1A and 1B The structure of the light-emitting device of Embodiment 2 is described. Substrate 101 serves as a support for the light-emitting device. Substrate 101 may be made of, for example, glass, quartz, or plastic.

[0186] It should be noted that although the above substrate 101 may be retained in a light-emitting device or an electronic device that is a product incorporating the light-emitting device of the embodiment of the present invention, substrate 101 only serves as a support for the light-emitting device during the processing of the light-emitting device and is not retained in the end product.

[0187] For the first electrode 102 formed on the substrate 101, it is preferable to use a metal, alloy, conductive compound, or a mixture thereof having a high work function (specifically, a work function of 4.0 eV or more). Specific examples are given below: indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide (IZO), indium oxide containing tungsten oxide and zinc oxide (IWZO). In addition, there are gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), metal nitride materials (such as titanium nitride), etc. It should be noted that in the present invention, since the first layer 111 in the EL layer 103 in contact with the first electrode 102 contains a composite material that facilitates hole injection, any known material can be used regardless of the work function of the first electrode 102, as long as the material can be used as an electrode material (e.g., metals, alloys, conductive compounds and their mixtures, and elements belonging to Group 1 or Group 2 of the periodic table).

[0188] These materials are generally formed by sputtering. For example, indium oxide-zinc oxide (IZO) films can be formed by sputtering using a target in which 1-20 wt% of zinc oxide is added to indium oxide; a film of indium oxide containing tungsten oxide and zinc oxide can be formed by sputtering using a target in which 0.5-5 wt% of tungsten oxide and 0.1-1 wt% of zinc oxide are added to indium oxide. Alternatively, vacuum evaporation, coating, inkjet, spin coating, etc. can be used.

[0189] In addition, in the EL layer 103 formed on the first electrode 102, when the following composite material is used for the first layer 111 formed in contact with the first electrode 102, any one of various metals, alloys, conductive compounds, and their mixtures can be used as the material for the first electrode 102, regardless of the work function. For example, aluminum (Al), silver (Ag), aluminum alloy containing silicon (AlSi), etc. can also be used.

[0190] Alternatively, any element belonging to Groups 1 and 2 of the periodic table can be used, that is, alkali metals such as lithium (Li) and cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca), and strontium (Sr), alloys containing them (e.g., MgAg and AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), alloys containing them, etc., materials with a low work function.

[0191] It should be noted that when the first electrode 102 is formed using an alkali metal, alkaline earth metal, or their alloy, vacuum evaporation or sputtering can be used. Alternatively, in the case of using silver paste, etc., coating, inkjet, etc. can be used.

[0192] The EL layer 103 formed on the first electrode 102 can be formed using known materials, and low molecular compounds or high molecular compounds can be used. It should be noted that the material forming the EL layer 103 is not limited to organic compounds and can include some inorganic compounds.

[0193] The EL layer 103 is formed by appropriately laminating a hole injection layer containing a high hole injection material, a hole transport layer containing a high hole transport material, a light emitting layer containing a light emitting material, an electron transport layer containing a high electron transport material, and an electron injection layer containing a high electron injection material, etc.

[0194] It should be noted that Figure 1A the EL layer 103 shown in includes, in order from the first electrode 102 side, a first layer (hole injection layer) 111, a second layer (hole transport layer) 112, a third layer (light emitting layer) 113, a fourth layer (electron transport layer 114), and a fifth layer (electron injection layer) 115.

[0195] The first layer 111 (hole injection layer) is a hole injection layer containing a substance having a high hole injection property. As the substance having a high hole injection property, molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, manganese oxide, etc. can be used. Alternatively, a phthalocyanine-based compound such as phthalocyanine (abbreviation: H2Pc), copper(II) phthalocyanine (abbreviation: CuPc), or vanadyl phthalocyanine (abbreviation: VOPc) can be used as a low-molecular organic compound. It should be noted that the fluorene derivative of the embodiment of the present invention described in Embodiment 1 can also be used in a similar manner.

[0196] In addition, examples of the low-molecular organic compound include aromatic amine compounds such as 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 (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), etc. It should be noted that the carbazole derivative of the embodiment of the present invention described in Embodiment 1 can also be used in a similar manner.

[0197] In addition, or any one of high-molecular compounds (for example, oligomers, dendrimers, or polymers) can be used. For example, examples of the high-molecular compound include poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), or poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine] (abbreviation: poly-TPD), etc. Alternatively, a high-molecular compound added with an acid can be used, for example, poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) or polyaniline / poly(styrenesulfonic acid) (PAni / PSS).

[0198] In addition, a composite material obtained by mixing a receptor substance into a substance having high hole transport properties can be used for the first layer 111. By using such a high hole transport property substance containing a receptor substance, the material used to form the electrode can be selected without considering the work function. In other words, not only high work function materials can be used for the first electrode 102, but also low work function materials can be used as the first electrode 102. Such a composite material can be formed by co-depositing a substance having high hole transport properties and a substance having receptor properties. It should be noted that in this specification, the term "composite" not only represents a state where two materials are simply mixed, but also represents a state where multiple materials are mixed and electrons are transferred between the materials.

[0199] As the organic compound for the composite material, various compounds can be used, such as aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (e.g., oligomers, dendrimers, or polymers). The organic compound for the composite material is preferably an organic compound having high hole transport properties. Specifically, a substance with a hole mobility greater than or equal to 10 -6 cm 2 / V is preferably used. However, any substance other than the above substances can also be used as long as it is a substance with higher hole transport properties than electron transport properties. Specific examples of the organic compound that can be used for the composite material are as follows.

[0200] For example, as the organic compound that can be used for the composite material, there are: aromatic amine compounds such as MTDATA, TDATA, DPAB, DNTPD, DPA3B, PCzPCA1, PCzPCA2, PCzPCN1, 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), and N,N′-bis(3-methylphenyl)-N,N'-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD); and carbazole derivatives such as 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(N-carbazolyl)]phenyl-10-phenylanthracene (abbreviation: CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene. It should be noted that the carbazole derivatives of the embodiments of the present invention described in Embodiment 1 can also be used in a similar manner.

[0201] In addition, aryl hydrocarbon compounds include, for example, 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-bis(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-bis(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 9,10-bis[2-(1-naphthyl)phenyl]-2-tert-butylanthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, and 2,3,6,7-tetramethyl-9,10-bis(1-naphthyl)anthracene.

[0202] In addition, aromatic hydrocarbon compounds include, for example, 2,3,6,7-tetramethyl-9,10-bis(2-naphthyl)anthracene, 9,9'-bianthracene, 10,10'-diphenyl-9,9'-bianthracene, 10,10'-bis(2-phenylphenyl)-9,9'-bianthracene, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthracene, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, pentacene, coronene, 4,4'-bis(2,2-diphenylethenyl)biphenyl (abbreviation: DPVBi), and 9,10-bis[4-(2,2-diphenylethenyl)phenyl]anthracene (abbreviation: DPVPA), etc.

[0203] As substances having acceptor properties, organic compounds such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ) and chloranil, and transition metal oxides can be given. In addition, there are oxides of metals in Groups 4-8 of the periodic table. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferably used because they have high electron-accepting properties. Among them, molybdenum oxide is particularly preferred because of its stability in air and low hygroscopicity, which makes it easy to handle.

[0204] It should be noted that for the first layer 111, a composite material formed from any of the above-mentioned polymer compounds such as PVK, PVTPA, PTPDMA, or poly-TPD and any of the above-mentioned acceptor substances can be used. It should also be noted that a composite material formed by combining the carbazole compound of the embodiment of the present invention described in Embodiment 1 with the above-mentioned substance having acceptor properties can also be used for the first layer 111.

[0205] The second layer 112 is a hole transport layer containing a material having high hole transport properties. It should be noted that the fluorene derivatives of the embodiments of the present invention described in Embodiment 1 can also be used for the second layer 112 in Embodiment 2. Since the above-mentioned fluorene derivatives of the embodiments of the present invention have a wide bandgap, it is difficult for the second layer 112 formed using the fluorene derivatives to absorb the excitation energy generated in the third layer (light-emitting layer) 113 adjacent to the second layer 112, and excitons are effectively confined in the light-emitting layer. Thus, a light-emitting element with high efficiency can be obtained.

[0206] In addition, the fluorene derivatives of the embodiments of the present invention described in Embodiment 1 can be used for both the first layer 111 and the second layer 112. In this case, the element can be easily formed and the material utilization efficiency can be improved. In addition, since the energy diagrams of the first layer 111 and the second layer 112 are the same or similar, carriers can be easily transported between the first layer 111 and the second layer 112.

[0207] The third layer 113 is a layer containing a material having high light-emitting properties. The low-molecular organic compounds described below can be used for the third layer 113. It should be noted that since the fluorene derivatives of the embodiments of the present invention described in Embodiment 1 have light-emitting properties, the fluorene derivatives can also be used as light-emitting materials.

[0208] As the light-emitting material, for example, a fluorescent compound that emits fluorescence or a phosphorescent compound that emits phosphorescence can be used.

[0209] Fluorescent compounds that can be used for the light-emitting layer 113, such as light-emitting materials that emit blue light, include N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), etc.

[0210] The light-emitting materials that emit green light include N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl-2-yl)]-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), etc.

[0211] The light-emitting materials that emit yellow light include rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), etc. In addition, examples of the light-emitting materials that emit red light include N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), etc.

[0212] Phosphorescent compounds that can be used in the light-emitting layer 113, for example, as substances that emit blue light, there are bis[2-(4',6'-difluorophenyl)pyridine-N,C 2′ iridium(III) tetra(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridine-N,C 2′ iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridine-N,C 2 '}iridium(III) (abbreviation: Ir(CF3ppy)2(pic)) or bis[2-(4',6'-difluorophenyl)pyridine-N,C 2 ']iridium(III) acetylacetonate (abbreviation: FIr(acac)), etc. Substances for green light emission include tris(2-phenylpyridine-N,C 2′ )iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridine-N,C 2′Iridium(III) (abbreviation: Ir(ppy)2(acac)), bis(1,2-diphenyl-1H-benzoimidazole)iridium(III) acetylacetonate (abbreviation: Ir(pbi)2(acac)), or bis(benzo[h]quinoline)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)), etc. Substances for yellow light emission include bis(2,4-diphenyl-1,3-oxazole-N,C 2 ')iridium(III) (abbreviation: Ir(dpo)2(acac)), bis[2-(4'-(pentafluorophenyl)phenyl)pyridine]iridium(III) acetylacetonate (abbreviation: Ir(p-PF-ph)2(acac)), or bis(2-phenylbenzothiazole-N,C 2 ')iridium(III) (abbreviation: Ir(bt)2(acac)), etc. Substances for orange light emission include tris(2-phenylquinoline-N,C 2 ')iridium(III) (abbreviation: Ir(pq)3), or bis(2-phenylquinoline-N,C 2 ')iridium(III) acetylacetonate (abbreviation: Ir(pq)2(acac)), etc. Substances for red light emission are organometallic complexes, for example, bis[2-(2'-benzo[4,5-a]thienyl)pyridineato-N,C 3 ')iridium(III) acetylacetonate (abbreviation: Ir(btp)2(acac)), bis(1-phenylisoquinolineato-N,C 2 ')iridium(III) (abbreviation: Ir(piq)2(acac), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: Ir(Fdpq)2(acac)) or platinum(II) 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinato (abbreviation: PtOEP), etc. In addition, rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: Tb(acac)3(Phen)), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: Eu(DBM)3(Phen)) or tris[1-(2-thienoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA)3(Phen)) exhibit light emission from rare earth metal ions (electron transfer between different multiplets); thus such rare earth metal complexes can be used as phosphorescent compounds.

[0213] The third layer 113 may have a structure in which the above-mentioned substance with high luminescence properties is dispersed in another substance. It should be noted that in the case of dispersion, the concentration of the dispersed substance (dopant) is preferably less than or equal to 20% by mass of the total amount. In addition, a known substance can be used as the substance with luminescence properties (host material) to be dispersed. A substance with a lowest unoccupied molecular orbital energy level (LUMO energy level) shallower (smaller absolute value) than that of the luminescent substance and a highest occupied molecular orbital energy level (HOMO energy level) deeper (larger absolute value) than that of the luminescent substance is preferably used. In addition, it is preferable that the band gap (Bg: the difference between the HOMO energy level and the LUMO energy level) of the host material is larger than the Bg of the dopant with luminescence properties. In addition, when the light emitted by the dopant is fluorescence at the S1 energy level, the dopant is preferably higher than the host material, and when the light emitted by the dopant is phosphorescence at the T1 energy level, the dopant is preferably higher than the host material.

[0214] Specifically, the metal complexes include tris(8-hydroxyquinolinato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-hydroxyquinolinato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-hydroxyquinolinato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-hydroxyquinolinato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), or bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0215] In addition, the heterocyclic compounds include 2-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 3-(biphenyl-4-yl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), bathophenanthroline (abbreviation: BPhen), or bathocuproine (abbreviation: BCP).

[0216] Alternatively, fused aromatic compounds such as 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-bis(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-bianthracene (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), or 3,3',3''-(benzene-1,3,5-triyl)tripyrene (abbreviation: TPB3) may also be used.

[0217] A variety of substances can be used as the substance with luminescent properties to be dispersed. For example, in order to inhibit crystallization, a crystallization-inhibiting substance such as rubrene may be further added. Additionally, NPB or Alq etc. may be further added to effectively transfer energy to the substance with luminescent properties. It should be noted that the fluorene derivatives of the embodiments of the present invention described in Embodiment 1 can be used. Using a structure in which a substance with high luminescent properties is dispersed in another substance can inhibit the crystallization of the third layer 113. In addition, concentration quenching caused by a high concentration of the substance with high luminescent properties can also be inhibited.

[0218] Furthermore, among the above substances, a substance with electron-transporting properties is particularly preferably used to disperse the substance with luminescent properties therein to form the third layer 113. Specifically, any of the above metal complexes and heterocyclic compounds; CzPA, DNA, and t-BuDNA among the above fused aromatic compounds; and compounds with larger molecules will be given below as substances that can be used for the fourth layer 114 can also be used.

[0219] Alternatively, the following polymer compounds can also be used for the third layer 113.

[0220] Luminescent substances for blue light emission include poly(9,9-dioctylfluorene-2,7-diyl) (abbreviation: PFO), [(9,9-dioctylfluorene-2,7-diyl)-(2,5-dimethoxybenzene-1,4-diyl)] copolymer (abbreviation: PF-DMOP), {(9,9-dioctylfluorene-2,7-diyl)-[N,N′-bis-(p-butylphenyl)-1,4-phenylenediamine]} copolymer (abbreviation: TAB-PFH), etc.

[0221] Luminescent materials for green light emission include poly(p-phenylenevinylene) (abbreviation: PPV), [(9,9-dihexylfluorene-2,7-diyl)-(benzo[2,1,3]thiadiazole-4,7-diyl)] cross-copolymer (abbreviation: PFBT), [(9,9-dioctyl-2,7-divinylenefluorenylene)-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene)] cross-copolymer, etc.

[0222] Luminescent materials for orange to red light emission include poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (abbreviation: MEH-PPV), poly(3-butylthiophene-2,5-diyl) (abbreviation: R 4 -PAT), {[9,9-dihexyl-2,7-bis(1-cyanovinylene)fluorenylene]-[2,5-bis(N,N′-diphenylamino)-1,4-phenylene]} cross-copolymer, {[2-methoxy-5-(2-ethylhexyloxy)-1,4-bis(1-cyanovinylenephenylene)]-[2,5-bis(N,N′-diphenylamino)-1,4-phenylene]} cross-copolymer (abbreviation: CN-PPV-DPD), etc.

[0223] The light-emitting layer 113 can be a stack of two or more layers. For example, when the first light-emitting layer and the second light-emitting layer are stacked in sequence from the hole-transporting layer side to form the light-emitting layer 113, the first light-emitting layer can be formed using a material with hole-transporting properties as the host material, and the second light-emitting layer can be formed using a material with electron-transporting properties as the host material. More preferably, a material with hole-transporting properties greater than its electron-transporting properties is used as the host material for the first light-emitting layer and a material with electron-transporting properties greater than its hole-transporting properties is used as the host material for the second light-emitting layer. With the above structure, light-emitting sites are formed between the first light-emitting layer and the second light-emitting layer, so that a more efficient device can be obtained.

[0224] When the light-emitting layer with the above structure is formed using multiple materials, the light-emitting layer can be co-evaporated by vacuum evaporation; or methods such as inkjet printing, spin coating, or dip coating can be used as methods for the mixed solution.

[0225] The fourth layer 114 is an electron-transporting layer containing a material with high electron-transporting properties. For example, for the fourth layer 114, metal complexes such as Alq, Almq3, BeBq2, BAlq, Znq, ZnPBO, or ZnBTZ can be used as low-molecular-weight organic compounds. Alternatively, heterocyclic compounds such as PBD, OXD-7, TAZ, TPBI, BPhen, or BCP can be used instead of metal complexes. The substances mentioned here mainly have an electron mobility greater than or equal to 10 -6 cm2 Those substances for / Vs. Note that any substance other than the above substances can also be used for the electron transport layer, as long as it is a substance with higher electron transport properties than hole transport properties. In addition, the electron transport layer is not limited to a single layer and can be a laminate of two or more layers formed by the above substances.

[0226] A polymer compound can also be used for the fourth layer 114. For example, [(9,9-dihexylfluorene-2,7-diyl)-(pyridine-3,5-diyl)] copolymer (abbreviation: PF-Py) or [(9,9-dioctylfluorene-2,7-diyl)-(2,2'-bipyridine-6,6'-diyl)] copolymer (abbreviation: PF-BPy), etc. can be used.

[0227] The fifth layer 115 is an electron injection layer containing a substance with high electron injection properties. For the fifth layer 115, an alkali metal, an alkaline earth metal or their compounds, such as lithium fluoride (LiF), cesium fluoride (CsF), or calcium fluoride (CaF2), can be used. Alternatively, an electron transport material layer containing an alkali metal, an alkaline earth metal or their compounds can be used. Specifically, an Alq layer containing magnesium (Mg) can be used. It should be noted that in this case, electrons can be more effectively injected from the second electrode 104.

[0228] For the second electrode 104, a metal, an alloy or a conductive compound or a mixture thereof with a low work function (specifically, a work function less than or equal to 3.8 eV), etc. can be used. Elements belonging to Groups 1 and 2 of the periodic table, namely alkali metals such as lithium (Li) and cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca) and strontium (Sr), alloys containing them (for example, MgAg and AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), alloys containing them, etc. are given as specific examples of such cathode materials.

[0229] It should be noted that when the second electrode 104 is formed using an alkali metal, an alkaline earth metal or their alloy, a vacuum evaporation method or a sputtering method can be used. In the case of using silver paste, etc., a coating method or an inkjet method, etc. can be adopted.

[0230] It should be noted that by providing the fifth layer 115, the second electrode 104 can be formed using any of a variety of conductive materials such as Al, Ag, ITO, and indium tin oxide containing silicon or silicon oxide, regardless of the work function. A film of such a conductive material can be formed by methods such as a sputtering method, an inkjet method, or a spin coating method.

[0231] In addition, for the method of forming the EL layer 103 in which the first layer (hole injection layer) 111, the second layer (hole transport layer) 112, the third layer (light-emitting layer) 113, the fourth layer (electron transport layer) 114, and the fifth layer (electron injection layer) 115 are stacked in sequence, any one of a variety of methods can be adopted, regardless of whether the method is a dry process or a wet process. For example, vacuum evaporation, inkjet printing, spin coating, etc. can be used. It should be noted that different forming methods can be used for each layer.

[0232] The second electrode 104 can be formed by a wet process (such as the sol-gel method using a metal paste) instead of a dry process (such as sputtering or vacuum evaporation).

[0233] Since holes usually flow between the first electrode 102 and the first layer (hole injection layer) 111, between the first layer (hole injection layer) 111 and the second layer (hole transport layer) 112, and between the second layer (hole transport layer) 112 and the third layer (light-emitting layer) 113, their HOMO energy levels (work function with respect to the metal) are preferably the same or almost the same, thereby reducing the carrier injection barrier between adjacent layers. Similarly, electrons usually flow between the third layer (light-emitting layer) 113 and the fourth layer (electron transport layer) 114, between the fourth layer (electron transport layer) 114 and the fifth layer (electron injection layer) 115, and between the fifth layer (electron injection layer) 115 and the second electrode 104, and their LUMO energy levels (work function with respect to the metal) are preferably the same or almost the same, thereby reducing the carrier injection barrier between adjacent layers. The difference is preferably less than or equal to 0.2 eV, more preferably less than or equal to 0.1 eV.

[0234] Preferably, the difference in HOMO energy levels between the second layer (hole transport layer) 112 and the third layer (light-emitting layer) 113 and the difference in LUMO energy levels between the third layer (light-emitting layer) 113 and the fourth layer (electron transport layer) 114 increase, so that carriers are confined in the light-emitting layer, and thus a more efficient light-emitting element can be obtained. It should be noted that in this case, when the barrier is too high, the driving voltage is high, which will become a burden on the element. Therefore, each difference is preferably less than or equal to 0.4 eV, more preferably less than or equal to 0.2 eV.

[0235] In the above light-emitting element of the present light-emitting embodiment, since the potential difference generated between the first electrode 102 and the second electrode 104 and the recombination of holes and electrons in the EL layer 103 result in the generation of current, light is emitted. Then the emitted light is extracted through one or both of the first electrode 102 and the second electrode 104. Accordingly, one or both of the first electrode 102 and the second electrode 104 are electrodes having light-transmitting properties.

[0236] As Figure 2A shown, when only the first electrode 102 has the light-emitting property, the emitted light is extracted from the substrate side through the first electrode 102. Alternatively, as Figure 2B shown, when only the second electrode 104 has the light-emitting property, the emitted light is extracted from the side opposite to the substrate 101 through the second electrode 104. As Figure 2C shown, when the first electrode 102 and the second electrode 104 each have the light-emitting property, the emitted light is simultaneously extracted from the substrate 101 side and the side opposite to the substrate 101 through the first electrode 102 and the second electrode 104.

[0237] The layer structure provided between the first electrode 102 and the second electrode 104 is not limited to the above structure. A structure other than the above structure can be adopted as long as it includes at least a second layer 112 (hole transport layer) and a third layer 113 (light-emitting layer).

[0238] Alternatively, as Figure 1B shown, a structure in which the second electrode 104 as a cathode, the EL layer 103, and the first electrode 102 as an anode are laminated on the substrate 101 in the above order can be used. It should be noted that in this case, the EL layer 103 has a structure in which a fifth layer 115, a fourth layer 114, a third layer 113, a second layer 112, a third layer 111, and the first electrode 102 are laminated on the second electrode 104 in the above order.

[0239] It should be noted that by using the light-emitting element of the present invention, a passive matrix light-emitting device or an active matrix light-emitting device can be manufactured, and in these devices, the driving of the light-emitting element is controlled by a thin film transistor (TFT).

[0240] It should be noted that in the case of manufacturing an active matrix light-emitting device, there is no particular limitation on the structure of the TFT. For example, a staggered TFT or an inverted staggered TFT can be appropriately used. In addition, the driving circuit formed on the TFT substrate can use both an n-type TFT and a p-type TFT at the same time or can be formed using only one of the n-type TFT or the p-type TFT. Moreover, there is no particular limitation on the crystallinity of the semiconductor film used in the TFT. An amorphous semiconductor film can be used, or a crystalline semiconductor film can be used.

[0241] In the light-emitting element described in Embodiment 2, since the second layer (hole transport layer) 112 is formed using the fluorene derivative of the embodiment of the present invention, not only can the element efficiency be improved, but also the power consumption can be reduced.

[0242] (Embodiment 3)

[0243] Refer to Figure 3A and 3B, in Embodiment 3, a mode of a light-emitting element (hereinafter referred to as a stacked element) having a structure in which a plurality of stacked light-emitting units (also referred to as EL layers) is described. The light-emitting element is a stacked light-emitting element having a plurality of light-emitting units between a first electrode and a second electrode. The respective structures of the light-emitting units may be similar to those in Embodiment 2. In other words, the light-emitting element described in Embodiment 2 is a light-emitting element having one light-emitting unit. In Embodiment 3, a light-emitting element having a plurality of light-emitting units is described.

[0244] In Figure 3A , between a first electrode 521 and a second electrode 522, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked together. The first electrode 521 and the second electrode 522 may be similar to the electrodes in Embodiment 2. The first light-emitting unit 511 and the second light-emitting unit 512 may have the same or different structures, and a structure similar to the structure described in Embodiment 2 may be used.

[0245] When a voltage is applied to the first electrode 521 and the second electrode 522, the charge generation layer 513 is a layer that injects electrons into the light-emitting unit from one side and injects holes into the light-emitting unit from the other side, and it may be a single-layer structure or a stacked structure of a plurality of layers. For the stacked structure of a plurality of layers, a structure in which the layer injecting holes is stacked with the layer injecting electrons is preferably used.

[0246] For the layer injecting holes, a semiconductor or an insulator such as molybdenum oxide, vanadium oxide, rhenium oxide, or ruthenium oxide may be used. Alternatively, the layer injecting holes may have a structure in which an acceptor substance is added to a substance having a high hole transport property. The layer containing the substance having a high hole transport property and the acceptor substance contains 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinoxaline dimethane (abbreviation: F4-TCNQ) or a metal oxide such as vanadium oxide, molybdenum oxide, or tungsten oxide. For the substance having a high hole transport property, various compounds such as aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, high-molecular compounds, oligomers, dendrimers, and polymers may be used. It should be noted that the fluorene derivative of the embodiment of the present invention described in Embodiment 1 may also be used in a similar manner. It should be noted that a substance having a hole mobility of greater than or equal to 10 -6 cm 2 / Vs is preferably used as the substance having a high hole transport property. However, any substance other than the above substances may also be used as long as it is a substance having a hole transport property higher than an electron transport property. Since the composite material of the substance having a high hole transport property and the acceptor substance has good carrier injection properties and good carrier transport properties, low-voltage driving and low-current driving can be achieved.

[0247] For the layer for injecting electrons, a semiconductor or an insulator such as lithium oxide, lithium fluoride, or cesium carbonate can be used. Alternatively, the hole injection layer can have a structure in which a donor substance is added to a substance having high hole transport properties. As the donor substance, an alkali metal, an alkaline earth metal, a rare earth metal, a metal of Group 13 of the periodic table, or their oxides or carbonates can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc. are preferably used. Alternatively, an organic compound such as tetrathiafulvalene can be used as the donor substance. The materials described in Embodiment 1 can be used as the substance having high electron transport properties. It should be noted that a substance having a hole mobility greater than or equal to 10 -6 cm 2 / Vs is preferably used as the substance having high hole transport properties. However, any substance other than the above substances can also be used as long as it is a substance having higher electron transport properties than hole transport properties. Since the composite material of the substance having high hole transport properties and the donor substance has good carrier injection properties and good carrier transport properties, low voltage driving and low current driving can be achieved.

[0248] In addition, the electrode material described in Embodiment 2 can be used for the charge generation layer 513. For example, the charge generation layer 513 can be formed by bonding a layer containing a substance having high hole transport properties and a metal oxide to a transparent conductive film. Considering the light extraction efficiency, the charge generation layer 513 is preferably a highly light-transmissive layer.

[0249] In any case, the charge generation layer 513 provided between the first light-emitting unit 511 and the second light-emitting unit 512 is acceptable as long as it is a layer that can inject charges into the light-emitting unit from one side and inject holes into the light-emitting unit from the other side when a voltage is applied to the first electrode 521 and the second electrode 522. For example, any structure of the charge generation layer 513 is acceptable as long as the charge generation layer 513 injects electrons and holes into the first light-emitting unit 511 and the second light-emitting unit 512, respectively, when a voltage is applied in such a way that the potential of the first electrode is higher than the potential of the second electrode.

[0250] In Embodiment 3, a light-emitting element having two light-emitting units is described, but a light-emitting element in which three or more light-emitting units are stacked can be similarly used, such as Figure 3BAs shown. By providing a plurality of light-emitting units in the light-emitting element of Embodiment 3, the light-emitting units being separated by the charge generation layer 513 between the pair of electrodes, light emission in a high-brightness region can be achieved while maintaining a low current density, and thus long-life light emission can be achieved. When the light-emitting element is used as a light-emitting device as an example of an application, the voltage drop caused by the resistance of the electrode material can be reduced, and thus uniform light emission can be achieved over a large area. In addition, a light-emitting device having low power consumption and capable of being driven at a low voltage can be achieved.

[0251] The light-emitting units emit lights of different colors, so that the entire light-emitting element emits light of a desired color. For example, in a light-emitting element having two light-emitting units, the lights emitted by the first light-emitting unit and the second light-emitting unit are complementary, and thus a light-emitting element that emits white light can be obtained as the entire light-emitting element. It should be noted that the term "complementary" represents the color relationship in the achromatic color obtained when colors are mixed. That is to say, by mixing the lights emitted as complementary colors by some substances, white light can be obtained. The same principle can be applied to a light-emitting element having three light-emitting units. For example, when the emission color of the first light-emitting unit is red, the emission color of the second light-emitting unit is green, and the emission color of the third light-emitting unit is blue, the light-emitting element provides white light emission as a whole.

[0252] It should be noted that Embodiment 3 can be appropriately combined with any other embodiment.

[0253] (Embodiment 4)

[0254] In Embodiment 4, a light-emitting device will be described with reference to Figure 4A and 4B which includes the light-emitting element of the present invention in a pixel portion. Figure 4A is a top view of the light-emitting device, Figure 4B is a cross-sectional view along Figure 4A the straight lines A-A' and B-B'.

[0255] In Figure 4A , reference numeral 401 refers to a driving circuit portion (source-side driving circuit), reference numeral 402 represents a pixel portion, reference numeral 403 refers to a driving circuit portion (gate-side driving circuit), and they are shown by dashed lines. Reference numeral 404 refers to a sealing substrate, reference numeral 405 refers to a sealing material, and the portion surrounded by the sealing material 405 is a space 407.

[0256] Note that the lead wire 408 is used to transmit signals, input the signals into the source-side driving circuit 401 and the gate-side driving circuit 403, and receive image signals, clock signals, start signals, reset signals, etc. from the flexible printed circuit (FPC) 409, and the FPC 409 serves as an external input terminal. Although only the FPC is shown, the FPC can be connected to a printed wiring board (PWB). The light-emitting device in this specification includes not only the light-emitting device itself but also a light-emitting device having an FPC or a PWB connected thereto.

[0257] Subsequently, the cross-sectional structure will be described with reference to Figure 4B In the element substrate 410, a driving circuit portion and a pixel portion are formed. In this case, one pixel in the pixel portion 402 and the source-side driving circuit 401 of the driving circuit portion is shown in the figure. A CMOS circuit serving as the source-side driving circuit 401 is formed, and this circuit is a combination of an n-channel TFT 423 and a p-channel TFT 424. Such a driving circuit can be formed using various circuits, such as a CMOS circuit, a PMOS circuit, or an NMOS circuit. Although a driving-integrated device in which the driving circuit is formed on a substrate is described in Embodiment 4, the present invention is not limited to this type, and the driving circuit can be formed outside the substrate.

[0258] The pixel portion 402 includes a plurality of pixels, and these pixels include a switching TFT 411, a current control TFT 412, and a first electrode 413 electrically connected to the drain of the current control TFT 412. Note that an insulator 414 is formed so as to cover the end portion of the first electrode 413.

[0259] To improve the coverage, it is preferable that when providing the insulator 414, the upper end portion or the lower end portion of the insulator 414 has a curved surface with a certain curvature. For example, when using a positive photosensitive acrylic resin as the material of the insulator 414, only the upper end portion of the insulator 414 has a curved surface with a certain radius of curvature (0.2 - 3 μm). Alternatively, the insulator 414 can be formed using a negative photosensitive material or a positive photosensitive material, the negative photosensitive material is insoluble in an etchant by light irradiation, and the positive photosensitive material is soluble in an etchant by light irradiation.

[0260] An EL layer 416 and a second electrode 417 are formed on the first electrode 413. In this case, the first electrode 413 can be formed using any of a variety of materials such as metals, alloys, and conductive compounds or mixtures thereof. Note that for specific materials, the materials described in Embodiment 2 can be used, and the materials can be used as materials that can be used for the first electrode.

[0261] EL layer 416 can be formed by any of a variety of methods, such as an evaporation method using an evaporation mask, an inkjet method, and a spin coating method. EL layer 416 has any of the structures described in Embodiment 2. In addition, for another material included in EL layer 416, a low molecular weight compound or a high molecular weight compound (including oligomers and dendrimers) can be used. For the material of the EL layer, not only organic compounds but also inorganic compounds can be used.

[0262] Second electrode 417 can be formed using any of a variety of metals, alloys, and conductive compounds or mixtures thereof. Among such materials, when second electrode 417 is used as a cathode, it is preferable to use a metal, alloy, and conductive compound or mixture thereof having a low work function (work function less than or equal to 3.8 eV). Elements of Group 1 or 2 of the periodic table are given as examples, that is, alkali metals such as lithium (Li) or cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca), or strontium (Sr), and alloys containing any of them (for example, MgAg and AlLi).

[0263] It should be noted that when the light generated in EL layer 416 is transmitted through second electrode 417, second electrode 417 can be formed by laminating a thin metal film and a transparent conductive film (indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide (IZO), or indium oxide containing tungsten oxide and zinc oxide, etc.).

[0264] Sealing substrate 404 is attached to element substrate 410 with a sealant 405; thus, a light-emitting element 418 is provided in a space 407 surrounded by element substrate 410, sealing substrate 404, and sealant 405. It should be noted that this space 407 is filled with a filler such as an inert gas (such as nitrogen or argon) or a sealing material 405.

[0265] Note that an epoxy resin is preferably used as sealant 405. The material for this purpose is preferably a material that does not allow moisture or oxygen to pass through. A glass substrate, a quartz substrate, or a plastic substrate made of, for example, glass fiber reinforced plastic (FRP), polyvinyl fluoride (PVF), polyester, acrylic materials, etc. can be used as the material for forming sealing substrate 404.

[0266] As described above, an active matrix light-emitting device having the light-emitting element of the present invention can be obtained.

[0267] In addition, the light-emitting element of the present invention can be used in a passive matrix light-emitting device instead of the above-described active matrix light-emitting device. Figure 5A and 5B A perspective view and a cross-sectional view of a passive matrix light-emitting device using the light-emitting element of the present invention are shown. Figure 5A is a perspective view of the light-emitting device, Figure 5B is alongFigure 5A Cross-sectional view of the X-Y line

[0268] In Figure 5A and 5B an EL layer 504 is provided between a first electrode 502 and a second electrode 503 on a substrate 501. An end portion of the first electrode 502 is covered with an insulating layer 505. Further, a partition layer 506 is provided on the insulating layer 505. Side walls of the partition layer 506 are inclined so that a distance between the two side walls gradually becomes narrower toward the substrate surface direction. In other words, a cross-section of the partition layer 506 in the narrow-side direction is trapezoidal, and a length of a bottom side (a side in contact with the insulating layer 505, which is one of a pair of parallel sides of the trapezoidal cross-section) is smaller than a length of a top side (a side not in contact with the insulating layer 505, which is the other of the pair of parallel sides). The partition layer 506 in this manner can prevent defects from occurring in the light-emitting element due to static charges or the like.

[0269] Therefore, a passive matrix light-emitting device including the light-emitting element of the present invention can be manufactured.

[0270] It should be noted that any light-emitting device (active matrix light-emitting device and passive matrix light-emitting device) described in Embodiment 4 is formed using the light-emitting element of the present invention and has high luminous efficiency, and thus a light-emitting device with low power consumption can be obtained.

[0271] Note that in Embodiment 4, an appropriate combination of the structures described in Embodiments 1-3 can be used.

[0272] (Embodiment 5)

[0273] In the embodiment, an electronic device including the light-emitting device of the present invention described in Embodiment 4 is described. Examples of the electronic device include: cameras such as video cameras and digital cameras; head-mounted displays, navigation systems, sound output devices (e.g., in-vehicle audio stereo systems or audio stereo devices), computers, game machines, portable information terminals (such as, mobile computers, mobile phones, portable game machines, e-book readers, etc.), image reproduction devices equipped with a recording medium (specifically, a device capable of reproducing a recording medium such as a digital versatile disc (DVD) and equipped with a display device capable of displaying an image), etc. Specific examples of these electronic devices are shown in Figures 6A - 6D in.

[0274] Figure 6A A television receiver according to an embodiment of the present invention is shown, which includes a housing 611, a support base 612, a display portion 613, a speaker portion 614, a video input terminal 615, etc. In the television receiver, the light-emitting device of the present invention can be applied to the display portion 613. Since the light-emitting element of the present invention has a feature of high emission efficiency, a television receiver with low power consumption can be obtained by using the light-emitting device of the present invention.

[0275] Figure 6B Disclosed is a computer according to an embodiment of the present invention, which includes a main body 621, a housing 622, a display section 623, a keyboard 624, an external connection port 625, a pointing device 626, etc. In this computer, the light-emitting device of the present invention can be applied to the display section 623. Since the light-emitting element of the present invention has the characteristic of high emission efficiency, a computer with low power consumption can be obtained by using the light-emitting device of the present invention.

[0276] Figure 6C Disclosed is a mobile phone according to an embodiment of the present invention, which includes a main body 631, a housing 632, a display section 633, a sound input section 634, a sound output section 635, operation keys 636, an external connection port 637, an antenna 638, etc. In this mobile phone, the light-emitting device of the present invention can be applied to the display section 633. Since the light-emitting element of the present invention has the characteristic of high emission efficiency, a mobile phone with low power consumption can be obtained by using the light-emitting device of the present invention.

[0277] Figure 6D Disclosed is a camera according to the present embodiment, which includes a main body 641, a display section 642, a housing 643, an external connection port 644, a remote control receiving section 645, an image receiving section 646, a battery 647, a sound input section 648, operation keys 649, an eyepiece section 650, etc. In this camera, the light-emitting device of the present invention can be applied to the display section 642. Since the light-emitting element of the present invention has the characteristic of high emission efficiency, a camera with low power consumption can be obtained by using the light-emitting device of the present invention.

[0278] As described above, the application range of the light-emitting device of the present invention is extremely wide, and the light-emitting device can be applied to various fields of electronic devices. By using the light-emitting device of the present invention, an electronic device with reduced power consumption can be obtained.

[0279] In addition, the light-emitting device of the present invention can be used as a lighting device. Figure 7 An example of a liquid crystal display device is shown, in which the light-emitting device of the present invention is used as a backlight. Figure 7 The liquid crystal display device shown includes a housing 701, a liquid crystal layer 702, a backlight 703, and a housing 704. The liquid crystal layer 702 is connected to a driver IC 505. The light-emitting device of the present invention serves as the backlight 703, and current is supplied through a terminal 706.

[0280] By using the light-emitting device of the present invention as the backlight of the above liquid crystal display, a backlight with low power consumption can be obtained. In addition, since the light-emitting device of the present invention is a surface-emitting device, a large area can be formed, and a backlight with a large area can also be obtained. Therefore, a large-area liquid crystal display with low power consumption can be obtained.

[0281] Figure 8 An example of using the light-emitting device of the present invention as a lighting device, a table lamp, is shown. Figure 8 The table lamp shown in includes a housing 801 and a light source 802, and the light-emitting device of the present invention is used as the light source 802. The light-emitting device of the present invention has a light-emitting element with high emission efficiency, so this light-emitting device can be used as a table lamp with low power consumption.

[0282] Figure 9 An example of using the light-emitting device of the present invention as an internal lighting system 901 is shown. Since the light-emitting device of the present invention can be enlarged, the light-emitting device can be used as a large-area lighting device. In addition, the light-emitting device of the present invention has a light-emitting element with high emission efficiency, so this light-emitting device can be used as a lighting device with low power consumption. In a room where the light-emitting device of the present invention is used as the internal lighting device 901, Figure 6A the television receiver 902 of the present invention shown in can be placed there, and public broadcasts or movies can be enjoyed there.

[0283] It should be noted that in Embodiment 5, an appropriate combination of the structures described in Embodiments 1-4 can be used.

[0284] (Example 1)

[0285] Synthesis Example 1

[0286] In Example 1, a synthesis example of the fluorene derivative represented by the general formula (G1) in Embodiment 1 and the embodiment of the present invention is described. Specifically, a synthesis method of 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) represented by the structural formula (101) in Embodiment 1 is described. The structure of BPAFLP is shown below.

[0287] [Chemical Formula 30]

[0288]

[0289] [Step 1: Synthesis method of 9-(4-bromophenyl)-9-phenylfluorene]

[0290] In a 100 mL three-necked flask, 1.2 g (50 mmol) of magnesium was heated under reduced pressure and stirred for 30 minutes to activate it. After the flask was cooled to room temperature, a few drops of dibromomethane were added under a nitrogen atmosphere, and it was confirmed that a foam was formed and heat was generated. After 12 g (50 mmol) of 2-bromobiphenyl dissolved in 10 mL of diethyl ether was slowly added dropwise to the mixture, the mixture was stirred and heated under reflux conditions for 2.5 hours to prepare a Grignard reagent.

[0291] 10 g (40 mmol) of 4-bromobenzophenone and 100 mL of diethyl ether were placed in a 500 mL three-necked flask. The pre-synthesized Grignard reagent was slowly added dropwise to the mixture, and the mixture was heated and stirred under reflux conditions for 9 hours.

[0292] After the reaction, the mixture was filtered to obtain a residue. The obtained residue was dissolved in 150 mL of ethyl acetate, and 1N hydrochloric acid solution was added thereto until the mixed solution became acidic, and the mixture was stirred for 2 hours. The organic layer of this solution was washed with water. Then magnesium sulfate was added to remove moisture. The suspension was filtered, and the obtained filtrate was concentrated to obtain a candy-like substance.

[0293] Next, the candy-like substance, 50 mL of glacial acetic acid and 1.0 mL of hydrochloric acid were added to a 500 mL recovery flask, and the mixture was added and stirred under a nitrogen atmosphere at 130 °C for 1.5 hours to carry out the reaction.

[0294] After the reaction, the reaction mixture solution was filtered to obtain a residue. The obtained residue was washed successively with water, aqueous sodium hydroxide solution, water and methanol, and then dried, thus obtaining 11 g of the target white powder with a yield of 69%. The reaction scheme of the above synthesis method is shown in the following (J-1).

[0295] [Chemical formula 31]

[0296]

[0297] [Step 2: Synthesis method of 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP)]

[0298] 3.2 g (8.0 mmol) of 9-(4-bromophenyl)-9-phenylfluorene, 2.0 g (8.0 mmol) of 4-phenyl-diphenylamine, 1.0 g (10 mmol) of sodium tert-butoxide and 23 mg (0.04 mmol) of bis(dibenzylideneacetone)palladium(0) were added to a 100 mL three-necked flask, and the atmosphere in the flask was replaced with nitrogen. Then 20 mL of anhydrous xylene was added to the mixture. After stirring the mixture under reduced pressure and degassing it, 0.2 mL (0.1 mmol) of tris(tert-butyl)phosphine (10 wt% hexane solution) was added to the mixture. The mixture was heated and stirred at 110 °C for 2 hours in a nitrogen atmosphere to effect the reaction.

[0299] After the reaction, 200 mL of toluene was added to the reaction mixture solution, and the resulting suspension was filtered through Florisil (produced by Wako Pure Chemical Industries, Ltd., catalog number 540-00135) and Celite (produced by Wako Pure Chemical Industries, Ltd., catalog number 531-16855). The obtained filtrate was concentrated and purified by silica gel column chromatography (elution solvent, toluene:hexane = 1:4). The concentrated fraction was concentrated, and acetone and methanol were added thereto. The mixture was irradiated with ultrasonic waves and then recrystallized to obtain 4.1 g of the target white powder with a yield of 92%. The reaction scheme of the above synthesis method is shown in the following (J-2).

[0300] [Chemical formula 32]

[0301]

[0302] The Rf value of the target substance was 0.41, the Rf value of 9-(4-bromophenyl)-9-phenylfluorene was 0.51, and the Rf value of 4-phenyl-diphenylamine was 0.27. These measured values were measured by silica gel column thin-layer chromatography (TLC) (elution solvent, ethyl acetate:hexane = 1:10).

[0303] The compound obtained in the above step 2 was subjected to nuclear magnetic resonance ( 1 1H-NMR) measurement. The measurement data are shown below. Figure 10A and 10B show 1 1H-NMR spectra. The measurement results showed that the fluorene derivative BPAFLP (abbreviation) of the present invention represented by the structural formula (101) was obtained.

[0304] 11H-NMR (CDCl3, 300 MHz): δ (ppm) = 6.63–7.02 (m, 3H), 7.06–7.11 (m, 6H), 7.19–7.45 (m, 18H), 7.53–7.55 (m, 2H), and 7.75 (d, J = 6.9, 2H).

[0305] The following tests were conducted on various physical properties of the obtained target substance BPAFLP (abbreviation).

[0306] The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V-550, manufactured by JASCO Corporation) (measurement range: 200 nm - 800 nm). Figure 11 The absorption spectra of the toluene solution and the thin film are shown. The horizontal axis represents the wavelength (nm), and the vertical axis represents the absorption intensity (arbitrary unit). The toluene solution was placed in a quartz cell for measurement, and the displayed spectrum was obtained by subtracting the absorption spectra of quartz and toluene from the absorption spectrum of the sample. For the thin film, the sample evaporated on a quartz substrate was measured, and the displayed spectrum was obtained by subtracting the absorption spectrum of quartz from the absorption spectrum of the sample. From these spectra, for the case of the toluene solution, there is an absorption peak at approximately 314 nm on the long-wavelength side, and for the case of the thin film, there is an absorption peak at approximately 324 nm on the long-wavelength side.

[0307] The emission spectrum was measured using a fluorescence spectrophotometer (FS920, manufactured by Hamamatsu Photonics). Figure 12 The emission spectra of the toluene solution and the thin film are shown. The horizontal axis represents the wavelength (nm), and the vertical axis represents the absorption intensity (arbitrary unit). The toluene solution was placed in a quartz cell for measurement, and for the thin film, the sample evaporated on a quartz substrate was measured. From these spectra, for the case of the toluene solution, the maximum emission wavelength at 386 nm (excitation wavelength: 330 nm) can be observed, and for the case of the thin film, the maximum emission wavelength at 400 nm (excitation wavelength: 349 nm) can be observed.

[0308] The results of measuring the thin film using a photoelectron spectrophotometer (AC-2, manufactured by Riken Keiki Co., Ltd) in this atmosphere showed that the HOMO energy level of the thin film was -5.63 eV. The Tauc curve of the thin film absorption spectrum showed that the absorption edge was 3.34 eV. Therefore, the energy gap in the solid state was approximately 3.34 eV, which indicates that the LUMO energy level of the thin film was -2.29 eV. This shows that BPAFLP (abbreviation) has a relatively deep HOMO energy level and a wide bandgap (Bg).

[0309] The oxidation-reduction reaction characteristics of BPAFLP (abbreviation) were detected using cyclic voltammetry (CV) curves. It should be noted that measurements were carried out using an electrochemical analyzer (ALS model 600A or 600C, manufactured by BAS Inc.).

[0310] It should be noted that for the measurement of oxidation characteristics, the potential of the working electrode relative to the reference electrode was scanned from -0.10 V to 1.50 V and then from 1.50 V to -0.10 V. The HOMO energy level was found to be -5.51 [eV]. In addition, the oxidation peak remained at a similar value even after 100 cycles. Accordingly, the redox repetition process between the oxidized state and the neutral state was found to have favorable characteristics.

[0311] Note the following description of the measurement method.

[0312] (Calculate the electrical potential energy of the reference electrode relative to the vacuum level)

[0313] First, calculate the electrical potential energy (eV) of the reference electrode (Ag / Ag + electrode) used in Example 1 relative to the vacuum level. In other words, calculate the Fermi level of the Ag / Ag + electrode. It is known that the redox potential of ferrocene in methanol relative to the standard hydrogen electrode is +0.610 [V vs. SHE] (Reference: Christian R. Goldsmith et al., J. Am. Chem. Soc., Vol. 124, No. 1, 83 - 96, 2002). On the other hand, using the reference electrode in Example 1, the redox potential of ferrocene in methanol was calculated to be +0.11 [V vs. Ag / Ag + . Therefore, it was found that the electrical potential energy of the reference electrode in Example 1 was 0.50 [eV] lower than that of the standard hydrogen electrode.

[0314] Note that the electrical potential energy of the standard hydrogen electrode relative to the vacuum level is known to be -4.44 eV (Reference: Toshihiro Ohnishi and Tamami Koyama, High molecular EL material, Kyoritsushuppan, pp. 64 - 67). Accordingly, calculate the electrical potential energy of the reference electrode used in Example 1 relative to the vacuum level as -4.44 - 0.50 = -4.94 [eV].[[]END]

[0315] (CV test conditions for the target substance)

[0316] For the solution used in CV measurement, dehydrated dimethylformamide (DMF, product of Sigma-Aldrich Inc., 99.8%, catalog number 22705-6) was used as the solvent. Tetra-n-butylammonium perchlorate (n-Bu4NClO4, Tokyo Chemical Industry Co., Ltd., catalog number T0836) was the supporting electrolyte, which was dissolved in the solvent to make the concentration of tetra-n-butylammonium perchlorate 100 mmol / L. In addition, the target substance to be measured was dissolved in this solvent to make its concentration 2 mmol / L. A platinum electrode (manufactured by BAS, PTE platinum electrode) was used as the working electrode, a platinum electrode (manufactured by BAS, VC-3 Pt counter electrode, 5 cm) was used as the auxiliary electrode, and an Ag / Ag+ electrode (manufactured by BAS, RE-7 reference electrode for non-aqueous solvents) was used as the reference electrode. It should be noted that the measurement was carried out at room temperature (20 °C - 25 °C). In addition, in all measurements, the scan rate in CV measurement was set to 0.1 V / s.

[0317] Next, the HOMO energy level was calculated based on the CV measurement. Figure 13 The CV measurement results showing the redox characteristics are as follows. Figure 13 As shown, the oxidation peak potential (from the neutral state to the oxidized state) E pa was 0.62 V. In addition, the reduction peak potential (from the oxidized state to the neutral state) was 0.52 V. Therefore, the half-wave potential (the intermediate potential between Epa and Epc), Epa + Epc / 2 [V] was calculated to be 0.57 V. This indicates that an oxidation reaction occurred, and the electric energy was +0.57 [V vs. Ag / Ag + . In this article, as described above, the electric potential energy of the reference electrode used in Example 1 relative to the vacuum level was -4.94 [eV]; therefore, it should be understood that the HOMO energy level of BPAFLP (abbreviation) was calculated as follows: -4.94 - 0.57 = -5.51 [eV].

[0318] The glass transition temperature was measured by differential scanning calorimetry (Pyris 1 DSC, manufactured by Perkin Elmer). According to the measurement results, the glass transition temperature was determined to be 107 °C. In this way, BPAFLP (abbreviation) had a high glass transition temperature and good heat resistance. In addition, there was no crystallization peak; therefore, it was found that BPAFLP (abbreviation) was a substance difficult to crystallize.

[0319] (Example 2)

[0320] Synthesis Example 2

[0321] In Example 2, a synthesis example of the fluorene derivative represented by the general formula (G1) in Embodiment 1 and in the embodiment of the present invention is described. Specifically, a synthesis method of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi) represented by the structural formula (151) in Embodiment 1 is described. The structure of BPAFLBi is shown below.

[0322] [Chemical formula 33]

[0323]

[0324] [Step 1: Synthesis method of 9-(4′-bromo-4-biphenylyl)-9-phenylfluorene]

[0325] In a 500 mL three-necked flask, 5.1 g (22 mmol) of 2-bromobiphenyl was added, and the atmosphere in the flask was replaced with nitrogen. Then, 200 mL of anhydrous tetrahydrofuran (abbreviation: THF) was added to the mixture, and the mixture solution was cooled to -78°C. A hexane solution of 14 mL (22 mmol) of n-butyllithium was added dropwise to the mixture solution, and the mixture was stirred for 2.5 hours. Thereafter, 6.7 g (20 mmol) of 4-benzoyl-4′-bromobiphenyl was added to the mixture, and the mixture was stirred at -78°C for 2 hours and then at room temperature for 85 hours.

[0326] After the reaction, 1N dilute hydrochloric acid was added to the reaction solution until the mixed solution became acidic, and the mixture was stirred for 4 hours. The solution was washed with water. After washing, magnesium sulfate was added to remove water. The suspension was filtered, and the resulting filtrate was concentrated and purified by silica gel column chromatography (elution solvent, hexane). The concentrated fraction was added with methanol, ultrasonic waves were applied, and then recrystallization was carried out to obtain the target white powder.

[0327] Next, the white powder, 50 mL of glacial acetic acid, and 1.0 mL of hydrochloric acid were added to a 200 mL recovery flask, and the mixture was added and stirred at 130°C for 2.5 hours under a nitrogen atmosphere to carry out the reaction.

[0328] After the reaction, the reaction mixture solution was filtered to obtain a filtrate. The resulting filtrate was dissolved in 100 mL of toluene, washed successively with water, an aqueous sodium hydroxide solution, and water, and magnesium sulfate was added thereto to remove water. The suspension was filtered, the resulting filtrate was concentrated, and acetone and methanol were added thereto. The mixture was irradiated with ultrasonic waves and then recrystallized to obtain 6.3 g of the target white powder with a yield of 67%. The reaction scheme of the above synthesis method is shown in the following (J-3).

[0329] [Chemical formula 34]

[0330]

[0331] [Step 2: Synthesis method of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi)]

[0332] Add 3.8 g (8.0 mmol) of 9-(4′-bromo-4-biphenylyl)-9-phenylfluorene, 2.0 g (8.0 mmol) of 4-phenyl-diphenylamine, 1.0 g (10 mmol) of sodium tert-butoxide, and 23 mg (0.04 mmol) of bis(dibenzylideneacetone)palladium(0) to a 100 mL three-necked flask, and displace the atmosphere in the flask with nitrogen. Then add 20 mL of anhydrous xylene to the mixture. After stirring the mixture under reduced pressure and degassing it, add 0.2 mL (0.1 mmol) of tris(tert-butyl)phosphine (10 wt% hexane solution) to the mixture. Heat and stir the mixture at 110 °C for 2 hours in a nitrogen atmosphere for reaction.

[0333] After the reaction, add 200 mL of toluene to the reaction mixture solution, and filter the resulting suspension through Florisil and C salt (Celite). Concentrate the obtained filtrate and purify it by silica gel column chromatography (elution solvent, toluene:hexane = 1:4). Concentrate the obtained fraction, and add acetone and methanol thereto. Irradiate the mixture with ultrasonic waves, and then recrystallize it to obtain 4.4 g of the target white powder with a yield of 86%. The reaction scheme of the above synthesis method is shown in the following (J-4).

[0334] [Chemical formula 35]

[0335]

[0336] The Rf value of the target substance is 0.51, the Rf value of 9-(4′-bromo-4-biphenylyl)-9-phenylfluorene is 0.56, and the Rf value of 4-phenyl-diphenylamine is 0.28. These measured values are obtained by silica gel column thin layer chromatography (TLC) (elution solvent, ethyl acetate:hexane = 1:10).

[0337] Perform nuclear magnetic resonance ( 1 1H-NMR) measurement on the compound obtained in Step 2. The measurement data are shown below. Figure 14A and 14B show 1 1H-NMR spectra. The measurement results show that the fluorene derivative BPAFLBi (abbreviation) of the present invention represented by the structural formula (151) is obtained.

[0338] 11H-NMR(CDCl3, 300 MHz): δ(ppm) = 7.04 (t, J = 6.6, 1H), 7.12–7.49 (m, 30H), 7.55–7.58 (m, 2H), and 7.77 (d, J = 7.8, 2H).

[0339] The following tests were conducted on various physical properties of the obtained target substance BPAFLBi (abbreviation).

[0340] The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V-550, manufactured by JASCO Corporation) (measurement range: 200 nm - 800 nm). Figure 15 The absorption spectra of the toluene solution and the thin film are shown. The horizontal axis represents the wavelength (nm), and the vertical axis represents the absorption intensity (arbitrary unit). The toluene solution was placed in a quartz cell for measurement, and the displayed spectrum was obtained by subtracting the absorption spectra of quartz and toluene from the absorption spectrum of the sample. For the thin film, the sample evaporated on a quartz substrate was measured, and the displayed spectrum was obtained by subtracting the absorption spectrum of quartz from the absorption spectrum of the sample. From these spectra, it can be seen that for the toluene solution, there is an absorption peak at approximately 340 nm on the long-wavelength side, and for the thin film, there is an absorption peak at approximately 341 nm on the long-wavelength side.

[0341] The emission spectrum was measured using a fluorescence spectrophotometer (FS920, manufactured by Hamamatsu Photonics). Figure 16 The emission spectra of the toluene solution and the thin film are shown. The horizontal axis represents the wavelength (nm), and the vertical axis represents the emission intensity (arbitrary unit). The toluene solution was placed in a quartz cell for measurement, and for the thin film, the sample evaporated on a quartz substrate was measured. From these spectra, for the toluene solution, the maximum emission wavelength at 386 nm (excitation wavelength: 345 nm) can be observed, and for the thin film, the maximum emission wavelengths at 399 nm and 419 nm (excitation wavelength: 348 nm) can be observed.

[0342] The measurement of the thin film using a photoelectron spectrophotometer (AC-2, manufactured by Riken Keiki Co., Ltd) in this atmosphere showed that the HOMO energy level of the thin film was -5.64 eV. The Tauc curve of the thin film absorption spectrum showed that the absorption edge was 3.28 eV. Therefore, the energy gap in the solid state was approximately 3.28 eV, which indicates that the LUMO energy level of the thin film was -2.36 eV. This shows that BPAFLBi (abbreviation) has a relatively deep HOMO energy level and a wide bandgap (Bg).

[0343] The oxidation-reduction reaction characteristics of BPAFLBi (abbreviation) were detected using cyclic voltammetry (CV) curves. It should be noted that measurements were carried out using an electrochemical analyzer (ALS model 600A or 600C, manufactured by BAS Inc.). The measurement method was similar to that of Example 1, so the description of the measurement method is omitted.

[0344] It should be noted that for the measurement of oxidation characteristics, the potential of the working electrode relative to the reference electrode was scanned from -0.10 V to 1.50 V and then from 1.50 V to -0.10 V. The HOMO energy level was found to be -5.49 [eV]. In addition, the oxidation peak remained at a similar value even after 100 cycles. Accordingly, it was found that the oxidation-reduction repetition process between the oxidized state and the neutral state had favorable characteristics.

[0345] Figure 17 CV measurement results showing the oxidation-reduction characteristics of BPAFLBi (abbreviation).

[0346] The glass transition temperature was measured using differential scanning calorimetry (Pyris 1 DSC, manufactured by Perkin Elmer). Based on the measurement results, the glass transition temperature was determined to be 126 °C. In this way, BPAFLBi (abbreviation) had a high glass transition temperature and good heat resistance. In addition, there was no crystallization peak; therefore, it was found that BPAFLBi (abbreviation) was a substance that was difficult to crystallize.

[0347] (Example 3)

[0348] In Example 3, the manufacturing method of a light-emitting element formed using the fluorene derivative 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) synthesized in Example 1 and the test results of the element characteristics are described.

[0349] The element structure of the light-emitting element in Example 3 is as Figure 18 shown. The fluorene derivative of the present invention (abbreviation: BPAFLP) was used to form the light-emitting element 2 in the hole transport layer 1512. In addition, the light-emitting element 1 was a comparative light-emitting element formed using 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) in the hole transport layer 1512. In order to make the light-emitting element 1 and the light-emitting element 2 have the same comparison conditions, the comparative light-emitting element 1 was formed on the same substrate as the light-emitting element 2, and the light-emitting element 1 was compared with the light-emitting element 2. The structural formula of the organic compound in Example 3 is as follows.

[0350] [Chemical formula 36]

[0351]

[0352] First, indium tin oxide containing silicon oxide is deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nanometers and the electrode area is 2 mm × 2 mm.

[0353] Then, an EL layer 1503 including a plurality of stacked layers is formed on the first electrode 1502. In Example 5, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0354] The substrate provided with the first electrode 1502 is fixed to the substrate jig of the vacuum evaporation apparatus with the surface provided with the first electrode 1502 facing downward. The pressure of the vacuum evaporation apparatus is reduced to about 10 -4 Pa. Then, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) and molybdenum(VI) oxide are co-evaporated on the first electrode 1502 to form the first layer 1511 (hole injection layer). The thickness is 50 nanometers, and the evaporation rate is controlled so that the weight ratio of NPB to molybdenum(VI) oxide is 4:1 = (NPB: molybdenum(VI) oxide). It should be noted that the co-evaporation method is a vapor deposition method in which a plurality of materials are vapor-deposited by a plurality of evaporation sources in one processing chamber at the same time.

[0355] Next, a hole transport material is deposited on the first layer 1511 by resistive heating by vapor deposition to a thickness of 10 nanometers to form the second layer 1512 (hole transport layer). It should be noted that the light-emitting element 1 is formed using 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), and the light-emitting element 2 is formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP).

[0356] Next, a third layer 1513 (light-emitting layer) is formed on the second layer 1512 by resistive heating by vapor deposition. The third layer 1513 is formed by co-evaporating 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA) and 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) to a thickness of 30 nanometers. Here, the evaporation rate is controlled so that the weight ratio of CzPA to PCBAPA is 1:0.10 = (CzPA:PCBAPA).

[0357] In addition, on the third layer 1513, a film of tris(8-hydroxyquinoline) aluminum(III) (abbreviation: Alq) with a thickness of 10 nm is formed by resistance heating using an evaporation method, and a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nm is formed thereon, thereby forming the fourth layer 1514 (electron transport layer).

[0358] On the fourth layer 1514, a lithium fluoride (LiF) film with a thickness of 1 nm is formed as the fifth layer 1515 (electron injection layer).

[0359] Finally, an aluminum film with a thickness of 200 nm is formed by resistance heating using an evaporation method to form the second electrode 1504. In this way, the comparative light-emitting element 1 and the light-emitting element 2 are formed.

[0360] It should be noted that except for the second layer 1512, the comparative light-emitting element 1 and the light-emitting element 2 are formed in the same steps.

[0361] The obtained comparative light-emitting element 1 and light-emitting element 2 are sealed in a glove box under a nitrogen atmosphere to prevent contact with air. Then, their operating characteristics are measured. Note that the measurement is carried out at room temperature (the atmosphere is maintained at 25 °C).

[0362] Figure 19 Show the current density and luminance characteristics of the comparative light-emitting element 1 and the light-emitting element 2. Figure 20 Show the voltage and luminance characteristics of the comparative light-emitting element 1 and the light-emitting element 2. Figure 21 Show the luminance and current efficiency characteristics of the comparative light-emitting element 1 and the light-emitting element 2. In Figure 19 the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 20 the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 21 the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 1 shows the respective voltages, chromaticities, and current efficiencies of the comparative light-emitting element 1 and the light-emitting element 2 near 1000 cd / m 2 .

[0363] [Table 1]

[0364] Voltage (V) Chromaticity x Chromaticity y Current Efficiency (cd / A) Comparative Light - Emitting Element 1 3.8 0.16 0.19 5.2 Light - Emitting Element 2 4.2 0.15 0.21 8.5

[0365] When the driving voltage of the light-emitting element 2 is 4.2 V, the luminance and current values are 880 cd / m 2and 0.41 mA. By comparing with the light-emitting element 1 using NPB (abbreviation) for the second layer 1512, it was found that the light-emitting element 2 using BPAFLP (abbreviation) for the second layer 1512 had a higher current efficiency. This is because it is considered that the carrier balance of the light-emitting element 2 was improved compared with the light-emitting element 1. Since the HOMO level of BPAFLP (abbreviation) is closer to the HOMO level of CzPA (abbreviation) (the host material of the light-emitting layer) than the HOMO level of NPB, it is considered that the hole injection property from the hole transport layer to the light-emitting layer was improved. In addition, since the LUMO level of BPAFLP (abbreviation) is higher than the LUMO level of NPB, it is considered that the electron blocking property from the light-emitting layer to the hole transport layer was improved. Further, since BPAFLP (abbreviation) has a wide bandgap (Bg) (compared with NPB), it is considered that the excitons generated in the third layer (light-emitting layer) 1513 do not transfer to the adjacent second layer 1512 (that is, there is no quenching) and are confined.

[0366] (Example 4)

[0367] In Example 4, the manufacturing method of the light-emitting element formed using the fluorene derivative 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) synthesized in Example 1 and the test results of the element characteristics are described.

[0368] The element structure of the light-emitting element in Example 4 is as Figure 18 shown. The above-mentioned fluorene derivative (abbreviation: BPAFLP) of the present invention was used for the hole transport layer 1512 to form the light-emitting element 3. The structural formula of the organic compound in Example 4 is as follows.

[0369] [Chemical formula 37]

[0370]

[0371] First, indium tin oxide containing silicon oxide was deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nm and the electrode area is 2 mm × 2 mm.

[0372] Then, an EL layer 1503 including a plurality of layers stacked was formed on the first electrode 1502. In Example 4, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0373] Fix the substrate provided with the first electrode 1502 on the substrate jig of the vacuum evaporation equipment, with the surface provided with the first electrode 1502 facing downwards. Reduce the pressure of the vacuum evaporation equipment to about 10 -4 Pa. Then, co-evaporate 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA) and molybdenum(VI) oxide on the first electrode 1502 to form the first layer 1511 (hole injection layer). The thickness is 50 nanometers, and control the evaporation rate so that the weight ratio of CzPA to molybdenum(VI) oxide is 4:1 = (CzPA: molybdenum(VI) oxide).

[0374] Next, deposit a hole transporting material on the first layer 1511 to a thickness of 10 nanometers by resistive heating through evaporation method to form the second layer 1512 (hole transporting layer). It should be noted that the light-emitting element 3 is formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP).

[0375] Next, form the third layer 1513 (light-emitting layer) on the second layer 1512 by resistive heating through evaporation method. The third layer 1513 is formed by co-evaporating 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA) and 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) to a thickness of 30 nanometers. Here, control the evaporation rate so that the weight ratio of CzPA to PCBAPA is 1:0.10 = (CzPA:PCBAPA).

[0376] After that, in a manner similar to the comparative light-emitting element 1, form the fourth layer electron transporting layer, the fifth layer electron injection layer and the second electrode. Thus, the light-emitting element 3 is formed.

[0377] Seal the obtained light-emitting element 3 in a glove box under a nitrogen atmosphere to prevent contact with air. Then measure the operating characteristics of the light-emitting element 3. Note that the measurement is carried out at room temperature (the atmosphere is maintained at 25 °C).

[0378] Figure 22 Show the current density and luminance characteristics of the light-emitting element 3. Figure 23 Show the voltage and luminance characteristics of the light-emitting element 3. Figure 24 Show the luminance and current efficiency characteristics of the light-emitting element 3. In Figure 22 the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 23 the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 24In this case, the vertical axis represents the current efficiency (cd / A), and the horizontal axis represents the luminance (cd / m 2 ). Further, Table 2 shows the voltage, chromaticity, and current efficiency of the light-emitting element 3 at around 1000 cd / m 2 .

[0379] [Table 2]

[0380] Voltage (V) Chromaticity x Chromaticity y Current Efficiency (cd / A) Light - Emitting Element 3 3.6 0.16 0.22 6.9

[0381] According to Example 4, it was confirmed that the light-emitting element using the fluorene derivative (abbreviation: BPAFLP) of the present invention has the characteristics and all functions as a light-emitting element. Further, from the results of the reliability test, it was found that a highly reliable light-emitting element was obtained, and in this light-emitting element, even when the light-emitting element continuously emits light, a short circuit caused by film defects or the like does not occur.

[0382] Figure 25 The results of the continuous illumination test showing the continuous light emission of the light-emitting element 3 under constant current driving are shown, and the initial luminance was set to 1000 cd / m 2 (assuming 1000 cd / m 2 is 100%, and the vertical axis represents the relative luminance). From Figure 25 the results, it can be seen that the light-emitting element 3 can exhibit 78% of the initial luminance even after 1000 hours, so that the light-emitting element 3 has a long life. Therefore, it was found that a light-emitting element with a long life can be obtained by using the BPAFLP (abbreviation) of the present invention.

[0383] (Example 5)

[0384] In Example 5, a method for manufacturing a light-emitting element formed using the fluorene derivative 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi) synthesized in Examples 1 and 2, a light-emitting element formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and test results of the element characteristics are described.

[0385] The element structure of the light-emitting element in Example 5 is as Figure 18 shown. The above-mentioned fluorene derivative of the present invention is used for forming a light-emitting element in the hole injection layer and the hole transport layer. The structural formula of the organic compound in Example 5 is as follows.

[0386] [Chemical Formula 38]

[0387]

[0388] First, indium tin oxide containing silicon oxide is deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nanometers and the electrode area is 2 mm × 2 mm.

[0389] Then, an EL layer 1503 including a plurality of stacked layers is formed on the first electrode 1502. In Example 5, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0390] The substrate provided with the first electrode 1502 is fixed to the substrate jig of the vacuum evaporation apparatus such that the surface provided with the first electrode 1502 faces downward. The pressure of the vacuum evaporation apparatus is reduced to about 10-4 Pa. Then, on the first electrode 1502, the fluorene derivative and molybdenum(VI) oxide of the embodiment of the present invention are co-evaporated to form the first layer 1511 (hole injection layer). The thickness is 50 nanometers, and the evaporation rate is controlled such that the weight ratio of the fluorene derivative to molybdenum(VI) oxide is 4:1 = (fluorene derivative: molybdenum(VI) oxide). It should be noted that the light emitting element 4 is formed using 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi) as the fluorene derivative, and the light emitting element 5 is formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) as the fluorene derivative.

[0391] Next, a hole transport material is deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nanometers to form the second layer 1512 (hole transport layer). Note that the light emitting element 4 is formed using BPAFLBi, and the light emitting element 5 is formed using BPAFLP.

[0392] Next, a third layer 1513 (light emitting layer) is formed on the second layer 1512 by evaporation using resistance heating. Note that in Example 5, the light emitting layer has two layers (a first light emitting layer and a second light emitting layer). The first light emitting layer is formed on the second layer 1512 by co-evaporating 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA) and 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) to a thickness of 15 nanometers. Here, the evaporation rate is controlled such that the weight ratio of CzPA to PCBAPA is 1:0.10 = (CzPA:PCBAPA).

[0393] Next, a second light-emitting layer is formed on the first light-emitting layer by vapor deposition using resistance heating. The second light-emitting layer is formed on the first light-emitting layer by co-evaporating 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA) and 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) to a thickness of 15 nm. Here, the evaporation rate is controlled such that the weight ratio of CzPA to PCBAPA is 1:0.05 = (CzPA:PCBAPA).

[0394] After that, in a manner similar to that of the comparative light-emitting element 1, a fourth electron transport layer, a fifth electron injection layer, and a second electrode are formed. Thus, light-emitting elements 4 and 5 are formed.

[0395] It should be noted that, except for the first layer 1511 and the second layer 1512, the light-emitting elements 4 and 5 are formed by the same steps.

[0396] The thus obtained light-emitting elements 4 and 5 are sealed in a glove box under a nitrogen atmosphere to prevent contact with air. Then, their operating characteristics are measured. Note that the measurement is carried out at room temperature (the atmosphere is maintained at 25 °C).

[0397] Figure 26 Show the current density and luminance characteristics of the light-emitting elements 4 and 5. Figure 27 Show the voltage and luminance characteristics of the light-emitting elements 4 and 5. Figure 28 Show the luminance and current efficiency characteristics of the light-emitting elements 4 and 5. In Figure 26 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 27 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 28 , the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 3 shows the respective voltages, chromaticities, current efficiencies, and external quantum efficiencies of the light-emitting elements 4 and 5 near 1000 cd / m 2 .

[0398] [Table 3]

[0399]

[0400] According to Example 5, it was confirmed that the light-emitting elements using BPAFLBi (abbreviation) and BPAFLP (abbreviation) respectively have the characteristics and all functions of a light-emitting element. In addition, from the reliability test results, it can be seen that highly reliable light-emitting elements are obtained, and in this light-emitting element, even when the light-emitting element emits light continuously, short circuits caused by film defects or the like do not occur.

[0401] Figure 29 Show the continuous illumination test results of the light-emitting element 4 and the light-emitting element 5 continuously emitting light under constant current drive, with the initial brightness set to 1000 cd / m 2 (assuming 1000 cd / m 2 is 100%, and the vertical axis represents the relative brightness). From Figure 29 the results, it can be seen that the light-emitting element 4 can exhibit 74% of the initial brightness even after 850 hours, and the light-emitting element 5 can exhibit 75% of the initial brightness even after 850 hours, making the light-emitting element 4 and the light-emitting element 5 have a long lifespan. Therefore, it was found that a light-emitting element with a long lifespan can be obtained by using BPAFLBi (abbreviation) and BPAFLP (abbreviation) of the present invention.

[0402] (Example 6)

[0403] In Example 6, a manufacturing method of a light-emitting element formed using the fluorene derivative 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) synthesized in Example 1 and test results of element characteristics are described.

[0404] The element structure of the light-emitting element in Example 6 is as Figure 18 shown. The above-mentioned fluorene derivative of the present invention is used for the hole transport layer to form the light-emitting element 6. The structural formula of the organic compound in Example 6 is as follows.

[0405] [Chemical formula 39]

[0406]

[0407] First, indium tin oxide containing silicon oxide is deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nanometers and the electrode area is 2 mm × 2 mm.

[0408] Then, an EL layer 1503 including a plurality of layers stacked is formed on the first electrode 1502. In Example 6, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0409] Fix the substrate provided with the first electrode 1502 on the substrate jig of the vacuum evaporation equipment, with the surface provided with the first electrode 1502 facing downwards. Reduce the pressure of the vacuum evaporation equipment to approximately 10-4 Pa. Then, co-evaporate 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) and molybdenum(VI) oxide on the first electrode 1502 to form the first layer 1511 (hole injection layer). The thickness is 50 nanometers, and control the evaporation rate so that the weight ratio of NPB to molybdenum(VI) oxide is 4:2 = (NPB: molybdenum(VI) oxide). It should be noted that the co-evaporation method is a vapor deposition method in which multiple materials are vapor-deposited by multiple evaporation sources in one processing chamber simultaneously.

[0410] Next, deposit a hole transporting material on the first layer 1511 to a thickness of 10 nanometers by vapor deposition using resistance heating to form the second layer 1512 (hole transporting layer). It should be noted that the light-emitting element 6 is formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and the light-emitting element 7 is formed using 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB).

[0411] Next, form the third layer 1513 (light-emitting layer) on the second layer 1512 by vapor deposition using resistance heating. Co-evaporate 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II) and (2-phenylpyridineato-N,C 2′ )iridium(III) acetylacetonate (abbreviation: Ir(ppy)2acac) to form a 40-nanometer-thick film as the third layer 1513. Here, control the evaporation rate so that the weight ratio of CO11II to Ir(ppy)2acac is 1:0.08 = (CO11II: Ir(ppy)2acac).

[0412] In addition, on the third layer 1513, form a 10-nanometer-thick film of bis(2-methyl-8-hydroxyquinoline)(4-phenylphenolate)aluminum(III) (abbreviation: BAlq) by vapor deposition using resistance heating, and form a 20-nanometer-thick film of bathophenanthroline (abbreviation: BPhen) thereon, thereby forming the fourth layer 1514 (electron transporting layer).

[0413] After that, form the fourth electron transporting layer, the fifth electron injection layer, and the second electrode in a manner similar to that of the comparative light-emitting element 1. Thus, the comparative light-emitting element 6 and the comparative light-emitting element 7 are formed.

[0414] It should be noted that the light-emitting element 6 and the comparative light-emitting element 7 are formed in the same steps except for the second layer 1512.

[0415] The thus obtained light-emitting element 6 and the comparative light-emitting element 7 were sealed in a glove box under a nitrogen atmosphere to prevent contact with air. Then, their operating characteristics were measured. Note that the measurement was carried out at room temperature (the atmosphere was maintained at 25°C).

[0416] Figure 30 Show the current density and luminance characteristics of the light-emitting element 6 and the comparative light-emitting element 7. Figure 31 Show the voltage and luminance characteristics of the light-emitting element 6 and the comparative light-emitting element 7. Figure 32 Show the luminance and current efficiency characteristics of the light-emitting element 6 and the comparative light-emitting element 7. In Figure 30 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 31 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 32 , the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 4 shows the respective voltages, chromaticities, current efficiencies, and external quantum efficiencies of the light-emitting element 6 and the comparative light-emitting element 7 near 1000 cd / m 2 .

[0417] [Table 4]

[0418]

[0419] Figure 33 Show the emission spectra of the light-emitting element 6 and the comparative light-emitting element 7.

[0420] As Figure 33 shown, in the comparative light-emitting element 7, in addition to the emission wavelength from the dopant, the emission wavelength from NPB in the hole transport layer was observed. This indicates that the ability of NPB to block electrons is low, and partial recombination occurs even in the NPB with an internal quantum efficiency. As a result, it is considered that the current efficiency and the external quantum efficiency are reduced. In addition, since NPB has a low triplet excitation energy, the triplet excitation energy is easily transferred from the light-emitting layer to NPB, which leads to a reduction in the current efficiency and the external quantum efficiency. On the other hand, in the light-emitting element 6, only the emission from the dopant in the light-emitting layer was observed, and the emission from BPAFLP (abbreviation) in the hole transport layer was not observed. Accordingly, it is shown that BPAFLP has a high electron blocking ability and also has a large triplet excitation energy. As a result, the generated excitation energy is mainly consumed by the dopant (the phosphorescent material in the light-emitting layer) to form light, and thus a high current efficiency can be obtained. Therefore, it is confirmed that BPAFLP (abbreviation) of the embodiment of the present invention can be used for the hole transport layer to obtain an efficient element.

[0421] (Example 7)

[0422] In Example 7, the manufacturing method of a light-emitting element formed by using the fluorene derivative 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) synthesized in Example 1 respectively and the test results of the element characteristics are described.

[0423] The element structures of the light-emitting elements 8 to 10 in Example 7 are as Figure 18 shown. For the light-emitting element 9, the above-mentioned fluorene derivative of the present invention is used to form a transport layer, and for the light-emitting element 10, the above-mentioned fluorene derivative of the present invention is used to form a hole injection layer and a hole transport layer respectively. The structural formulas of the organic compounds in Example 7 are shown below.

[0424] [Chemical formula 40]

[0425]

[0426] First, indium tin oxide containing silicon oxide is deposited on the substrate 1501 by sputtering to form a first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nm, and the electrode area is 2 mm × 2 mm.

[0427] Then, an EL layer 1503 including a plurality of layers stacked is formed on the first electrode 1502. In Example 7, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0428] The substrate provided with the first electrode 1502 is fixed to the substrate jig of the vacuum evaporation apparatus with the surface provided with the first electrode 1502 facing downward. The pressure of the vacuum evaporation apparatus is reduced to about 10 -4 Pa. Then, a hole injection material is deposited on the first electrode 1502 to a thickness of 50 nm to form a first layer 1511 (hole injection layer). It should be noted that when forming the light-emitting elements 8 and 9, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) and molybdenum(VI) oxide are co-evaporated to form the first layer 1511 (hole injection layer 1511). The thickness is 50 nm, and the evaporation rate is controlled so that the weight ratio of NPB to molybdenum(VI) oxide is 4:2 = (NPB: molybdenum(VI) oxide). In addition, when forming the light-emitting element 10, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) and molybdenum(VI) oxide are co-evaporated to form the first layer 1511 (hole injection layer). The thickness is 50 nm, and the evaporation rate is controlled so that the weight ratio of BPAFLP to molybdenum(VI) oxide is 4:2 = (BPAFLP: molybdenum(VI) oxide).

[0429] Next, a hole transport material was deposited on the first layer 1511 to a thickness of 10 nm by resistance heating using an evaporation method to form a second layer 1512 (hole transport layer). It should be noted that the light-emitting element 8 was formed using 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), and the light-emitting elements 9 and 10 were formed using 4-phenyl-4'-(9-phenylfluoren-3-yl)triphenylamine (abbreviation: BPAFLP).

[0430] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by resistance heating using an evaporation method. 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), and iridium(III) bis{2-(4-fluorophenyl)-3,5-dimethylpyridinecarboxylato}(picolinato) (abbreviation: Ir(dmFppr)2pic) were co-evaporated to form a 40-nm-thick film as the third layer 1513. Here, the evaporation rate was controlled so that the weight ratio of CO11II to PCBA1BP and Ir(dmFppr)2pic was 1:0.15:0.1 = (CO11II:PCBA1BP:Ir(dmFppr)2pic).

[0431] Thereafter, in a manner similar to that of the comparative light-emitting element 1, a fourth layer electron transport layer, a fifth layer electron injection layer, and a second electrode were formed. Thus, the light-emitting elements 8 to 10 were formed.

[0432] It should be noted that the light-emitting elements 8 to 10 were formed in the same steps except for the first layer 1511 and the second layer 1512.

[0433] The light-emitting elements 8 to 10 thus obtained were sealed in a glove box under a nitrogen atmosphere to prevent contact with air. Then, their operating characteristics were measured. Note that the measurement was performed at room temperature (the atmosphere was maintained at 25 °C).

[0434] Figure 34 Show the current density and luminance characteristics of the light-emitting elements 8 to 10. Figure 35 Show the voltage and luminance characteristics of the light-emitting elements 8 to 10. Figure 36 Show the luminance and current density characteristics of the light-emitting elements 8 to 10. In Figure 34 the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 35In [the figure], the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 36 , the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 5 shows the respective voltages, chromaticities, current efficiencies, and external quantum efficiencies of light-emitting elements 8 to 10 near 1000 cd / m 2 .

[0435] [Table 5]

[0436]

[0437] Light-emitting elements 8 to 10 can each achieve high luminous efficiency; however, it was found that light-emitting element 9 using BPAFLP for the hole transport layer has a higher current efficiency than light-emitting element 8. In addition, it was found that light-emitting element 10 using BPAFLP for both the hole injection layer and the hole transport layer has a higher current efficiency than light-emitting element 9.

[0438] Figure 37 shows the results of a continuous illumination test in which light-emitting elements 8 to 10 continuously emit light under constant current driving, with the initial luminance set to 1000 cd / m 2 (assuming 1000 cd / m 2 is 100%, and the vertical axis represents relative luminance). From Figure 37 's results, it can be seen that light-emitting element 8 can exhibit 64% of the initial luminance even after 650 hours. Light-emitting element 9 can exhibit 71% of the initial luminance after 500 hours, and light-emitting element 10 can exhibit 72% of the initial luminance after 500 hours. Therefore, it was found that using BPAFLP (abbreviation) of the embodiment of the present invention can obtain a light-emitting element with a long lifespan.

[0439] (Example 8)

[0440] Here, the simulation results shown indicate that the fluorene derivative of the embodiment of the present invention is suitable for use as a hole transport material.

[0441] The structural formula used in the simulation is as shown below.

[0442] [Chemical Formula 41]

[0443]

[0444] First, the most stable structures of structural formula (101) (abbreviation: BPAFLP), structural formula (109), structural formula (114), structural formula (151) (abbreviation: BPAFLBi), structural formula (164), and NPB in the singlet and triplet states were calculated using density functional theory. Gaussian 03 was used as the quantum chemistry calculation program. The 6-311G(d,p) basis function was used for H, C, and N atoms. The B3LYP functional was used.

[0445] Next, using the most stable structures in the singlet and triplet states obtained from the above calculations, the excitation energies of structural formula (101) (abbreviation: BPAFLP), structural formula (109), structural formula (114), structural formula (151) (abbreviation: BPAFLBi), structural formula (164), and NPB were calculated respectively using time-dependent density functional theory. The basis function and functional used in this calculation were the same as those above.

[0446] Table 6 shows the energy level results of the highest occupied molecular orbital (HOMO) energy level of the most stable structure in the singlet state obtained from the above calculations.

[0447] [Table 6]

[0448]

[0449] From the results in Table 6, it can be seen that the HOMO energy level of the above-mentioned fluorene derivatives is lower than that of NPB. Therefore, it is proved that when any of the above-mentioned fluorene derivatives is used as a hole transport material, compared with NPB, the fluorene derivative has good properties of injecting holes into the light-emitting layer with a deeper HOMO energy level.

[0450] Table 7 shows the results of the first excitation energy (singlet) of the most stable structure in the singlet state calculated by TDDFT.

[0451] [Table 7]

[0452]

[0453] From Table 7, it can be seen that when any of the above-mentioned fluorene derivatives is used as a hole transport material, compared with NPB, it is difficult for the fluorene derivative to release singlet excitons at the interface between the light-emitting layer and the hole transport layer to the hole transport layer side.

[0454] Table 8 shows the results of the first excitation energy (triplet) of the most stable structure in the triplet state calculated by TDDFT.

[0455] [Table 8]

[0456]

[0457]

[0458] As can be seen from Table 8, when any of the above-mentioned fluorene derivatives is used as a hole transport material, compared with NPB, it is difficult for the fluorene derivative to release triplet excitons at the interface between the light-emitting layer and the hole transport layer from the light-emitting layer to the hole transport layer side. In addition, it was found that when any fluorene derivative is used as a phosphorescent host material, the guest material can be easily excited.

[0459] (Example 9)

[0460] In Example 9, the manufacturing method of a light-emitting element formed using the fluorene derivative 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) synthesized in Example 1 and the test results of the element characteristics are described.

[0461] The element structures of the light-emitting element 11 and the comparative light-emitting element 12 in Example 9 are as Figure 18 shown. The above-mentioned fluorene derivative of the present invention is used for the hole injection layer and the hole transport layer to form the light-emitting element 11.

[0462] First, indium tin oxide containing silicon oxide is deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nanometers and the electrode area is 2 mm × 2 mm.

[0463] Then, an EL layer 1503 including a plurality of layers stacked is formed on the first electrode 1502. In Example 9, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0464] The substrate provided with the first electrode 1502 is fixed to the substrate jig of the vacuum evaporation apparatus so that the surface provided with the first electrode 1502 faces downward. The pressure of the vacuum evaporation apparatus is reduced to about 10 -4Pa. Then, on the first electrode 1502, a hole injection material is deposited to a thickness of 50 nm to form the first layer 1511 (hole injection layer). When forming the light-emitting element 11, 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) and molybdenum(VI) oxide are co-evaporated to form the first layer 1511 (hole injection layer 1511). The thickness is 50 nm, and the evaporation rate is controlled so that the weight ratio of BPAFLP to molybdenum(VI) oxide is 4:2 = (BPAFLP: molybdenum(VI) oxide). In addition, when forming the comparative light-emitting element 12, 4,4′,4″-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA) and molybdenum(VI) oxide are co-evaporated to form the first layer 1511 (hole injection layer). The thickness is 50 nm, and the evaporation rate is controlled so that the weight ratio of TCTA to molybdenum(VI) oxide is 4:2 = (TCTA: molybdenum(VI) oxide).

[0465] Next, a hole transport material is deposited on the first layer 1511 to a thickness of 10 nm by resistive heating through evaporation to form the second layer 1512 (hole transport layer). It should be noted that the light-emitting element 11 is formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and the comparative light-emitting element 12 is formed using 4,4′,4″-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA).

[0466] Next, a third layer 1513 (light-emitting layer) is formed on the second layer 1512 by resistive heating through evaporation. 9-[4-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)phenyl]-9H-carbazole (abbreviation: CzTAZ1) and bis[2-(4′,6′-difluorophenyl)pyridinato-N,C 2′ iridium(III) (abbreviation: FIrpic) are co-evaporated to form a 30-nm-thick film as the third layer. Here, the evaporation rate is controlled so that the weight ratio of CzTAZ1 to FIrpic is 1:0.06 = (CzTAZ1:FIrpic).

[0467] In addition, on the third layer 1513, a film of 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ01) with a thickness of 10 nm is formed by resistive heating through evaporation, and a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nm is formed thereon, thereby forming the fourth layer 1514 (electron transport layer).

[0468] After that, in a manner similar to that of the comparative light-emitting element 1, a fifth layer electron injection layer and a second electrode are formed. Thus, the light-emitting element 11 and the comparative light-emitting element 12 are formed.

[0469] Note that, except for the first layer 1511 and the second layer 1512, the light-emitting elements 11 to the comparative light-emitting element 12 are formed in the same steps.

[0470] The obtained light-emitting elements 11 and the comparative light-emitting element 12 are sealed in a glove box in a nitrogen atmosphere to prevent contact with air. Then, their operating characteristics are measured. Note that the measurement is carried out at room temperature (the atmosphere is maintained at 25 °C).

[0471] Figure 38 Show the current density and luminance characteristics of the light-emitting element 11 and the comparative light-emitting element 12. Figure 39 Show the voltage and luminance characteristics of the light-emitting element 11 and the comparative light-emitting element 12. Figure 40 Show the luminance and current efficiency characteristics of the light-emitting element 11 and the comparative light-emitting element 12. In Figure 38 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 39 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 40 , the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 9 shows the respective voltages, chromaticities, current efficiencies, and external quantum efficiencies of the light-emitting element 11 and the comparative light-emitting element 12 near 1000 cd / m 2 .

[0472] [Table 9]

[0473]

[0474]

[0475] When the driving voltage of the light-emitting element 11 using the fluorene derivative BPAFLP (abbreviation) of the present invention for the first layer 1511 and the second layer 1512 is 5.2 V, the luminance is 910 cd / m 2 , and the current value is 0.18 mA. When the driving voltage of the comparative light-emitting element 12 using TCTA (abbreviation) instead of BPAFLP (abbreviation) is 5.2 V, the luminance is 850 cd / m2, and the current value is 0.19 mA. Therefore, it is confirmed that the light-emitting element 11 using BPAFLP (abbreviation) for the first layer 1511 and the second layer 1512 has a higher current efficiency compared with the comparative light-emitting element 12. It is found that applying BPAFLP (abbreviation) of the embodiment of the present invention to the hole injection layer and the hole transport layer can obtain a highly efficient light-emitting element.

[0476] Figure 41Show the emission spectra of the light-emitting element 11 and the comparative light-emitting element 12.

[0477] In both the light-emitting element 11 and the comparative light-emitting element 12, the emission spectra from the phosphorescent dopant material FIrpic (abbreviation) were observed, and no light emission from the adjacent layer of the third layer 1513 was observed. This indicates that in both elements, carriers preferably recombine in the third layer 1513, and light can be emitted from a good carrier balance. It is shown that since the light-emitting element 11 shows a higher current efficiency compared with the comparative light-emitting element 12 at this time, BPAFLP (abbreviation) has a better carrier balance (blocking electrons from the third layer 1513 and obtaining more holes flowing to the third layer 1513), and its triplet excitation energy is also high. At this time, the LUMO energy level of BPAFLP (abbreviation) in the embodiment of the present invention is almost the same as that of TCTA (abbreviation) (-2.30 eV), and the band gap (Bg) of BPAFLP (abbreviation) is narrower than that of TCTA (abbreviation) (3.40 eV); therefore, BPAFLP (abbreviation) in the embodiment of the present invention is a material with higher hole transport properties. Therefore, it is considered that carrier recombination can be effectively carried out in the light-emitting layer, and thus higher efficiency can be obtained.

[0478] (Example 10)

[0479] In Example 10, the manufacturing method of a light-emitting element formed using the fluorene derivative 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) synthesized in Example 1 and the test results of the element characteristics are described.

[0480] The element structure of the light-emitting element 13 in Example 10 is as Figure 18 shown. The above-mentioned fluorene derivative (abbreviation: BPAFLP) of the present invention is used for the hole injection layer and the hole transport layer to form the light-emitting element 13. The structural formulas of the organic compounds used in Example 10 are as follows.

[0481] First, indium tin oxide containing silicon oxide is deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 is 110 nm, and the electrode area is 2 mm × 2 mm.

[0482] Then, an EL layer 1503 including a plurality of layers stacked is formed on the first electrode 1502. In Example 9, the EL layer 1503 has a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) are stacked in sequence.

[0483] Fix the substrate provided with the first electrode 1502 on the substrate jig of the vacuum evaporation equipment, with the surface provided with the first electrode 1502 facing downwards. Reduce the pressure of the vacuum evaporation equipment to about 10 -4 Pa. Then, deposit a hole injection material on the first electrode 1502 to a thickness of 50 nm to form the first layer 1511 (hole injection layer). When forming the light-emitting element 13, co-evaporate 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) and molybdenum(VI) oxide to form the first layer 1511 (hole injection layer 1511). The thickness is 50 nm, and control the evaporation rate so that the weight ratio of BPAFLP to molybdenum(VI) oxide is 4:2 = (BPAFLP: molybdenum(VI) oxide).

[0484] Next, deposit a hole transport material on the first layer 1511 to a thickness of 10 nm by evaporation using resistance heating to form the second layer 1512 (hole transport layer). It should be noted that the light-emitting element 13 is formed using 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP).

[0485] Next, form the third layer 1513 (light-emitting layer) on the second layer 1512 by evaporation using resistance heating. Co-evaporate 4-[3-(benzo[9,10]phenanthren-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II) and tris(2-phenylpyridine-N,C 2′ )iridium(III) (abbreviation: Ir(ppy)3) to form the third layer 1513. Here, control the evaporation rate so that the weight ratio of mDBTPTp-II to Ir(ppy)3 is 1:0.08 = (mDBTPTp-II: Ir(ppy)3).

[0486] In addition, on the third layer 1513, form an mDBTPTp-II film with a thickness of 10 nm by evaporation using resistance heating, and form a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nm thereon, thereby forming the fourth layer 1514 (electron transport layer).

[0487] After that, in a manner similar to the comparative light-emitting element 1, form the fifth layer electron injection layer and the second electrode. Thus, the light-emitting element 13 is formed.

[0488] Seal the obtained light-emitting element 13 in a glove box under a nitrogen atmosphere to prevent contact with air. Then measure the operating characteristics of the light-emitting element 13. Note that the measurement is carried out at room temperature (the atmosphere is maintained at 25 °C).

[0489] Figure 42 Show the current density and luminance characteristics of the light-emitting element 13. Figure 43 Show the voltage and luminance characteristics of the light-emitting element 13.Figure 44 Shows the luminance and current efficiency characteristics of the light-emitting element 13. In Figure 42 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 43 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 44 , the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 10 shows the voltage, chromaticity, current efficiency, and external quantum efficiency of the light-emitting element 13 near 1000 cd / m 2 .

[0490] [Table 10]

[0491]

[0492] According to Example 10, it was confirmed that the light-emitting element using the fluorene derivative (abbreviation: BPAFLP) of the present invention has characteristics sufficient to be used as a light-emitting element. In addition, from the results of the reliability test, it can be seen that a highly reliable light-emitting element was obtained, and in this light-emitting element, even when the light-emitting element emits light continuously, a short circuit caused by film defects or the like does not occur.

[0493] In addition, a continuous illumination test was conducted by continuously emitting light from the light-emitting element 13 under constant current driving, and the initial luminance was set to 1000 cd / m 2 . Even after 1900 hours, 86% of the initial luminance was still maintained. Therefore, it was found that the light-emitting element 13 has a long life. Therefore, it was confirmed that applying BPAFLP (abbreviation) of the embodiment of the present invention to the hole injection layer can obtain a light-emitting element with a long life.

[0494] (Example 11)

[0495] 《Synthesis Example 3》

[0496] In Example 11, a synthesis example of the fluorene derivative represented by the general formula (G1) in Embodiment 1 and the embodiment of the present invention is described. Specifically, a synthesis method of 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP) represented by the structural formula (118) in Embodiment 1 is described. The structure of mBPAFLP is shown below.

[0497] [Chemical Formula 42]

[0498]

[0499] [Step 1: Synthesis method of 9-(3-bromophenyl)-9-phenylfluorene]

[0500] To a 200 mL three-necked flask, add 30 mL of an anhydrous THF solution of 4.2 g (18 mmol) of 2-bromobiphenyl, and stir the mixture solution at -78 °C. Dropwise add 11 mL (18 mmol) of a hexane solution (1.57 M) of n-BuLi to the mixture solution, and stir the mixture for 2.5 h. Then, dropwise add 40 mL of an anhydrous THF solution of 3.9 g (15 mmol) of 3-bromobenzophenone to the mixture, stir the mixture for 2 h, and stir at room temperature for 16 h.

[0501] After the reaction, add 1 N dilute hydrochloric acid to the mixture solution, and stir the mixture for 1 h. Wash the mixture with water. Concentrate the obtained organic phase to obtain a candy-like substance.

[0502] Next, add the candy-like substance, 20 mL of glacial acetic acid, and 1.0 mL of hydrochloric acid to a 200 mL recovery flask, and add and stir the mixture at 130 °C under a nitrogen atmosphere for 2 h to carry out the reaction.

[0503] After the reaction, drop the reaction mixture solution into 150 mL of ice water to precipitate a caramel-like solid. Decant to remove the insoluble components. Dissolve the caramel-like solid in 100 mL of toluene, add a saturated aqueous solution of sodium bicarbonate thereto, and stir the toluene solution until no more bubbles are generated. Wash the organic layer with water, and then add silica gel to absorb moisture. Concentrate the filtrate obtained by filtering the mixture, add methanol thereto. Assist the mixture with ultrasonic waves while cooling with ice, and then filter the resulting solid. Obtain 4.9 g of the target white powder with a yield of 83%. The reaction scheme of the above synthesis method is shown in the following (J-5).

[0504] [Chemical formula 43]

[0505]

[0506] [Step 2: Synthesis method of 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP)]

[0507] Add 2.4 g (6.0 mmol) of 9-(3-bromophenyl)-9-phenylfluorene, 1.5 g (6.0 mmol) of 4-phenyl-diphenylamine, 1.0 g (10 mmol) of sodium tert-butoxide, and 3.0 mg (0.005 mmol) of bis(dibenzylideneacetone)palladium(0) to a 200 mL three-necked flask, and displace the atmosphere in the flask with nitrogen. Then add 25 mL of anhydrous xylene to the mixture. After stirring the mixture under reduced pressure and degassing it, add 0.2 mL (0.1 mmol) of tris(tert-butyl)phosphine (10 wt% hexane solution) to the mixture. Heat and stir the mixture at 130 °C for 2.5 h in a nitrogen atmosphere to effect the reaction.

[0508] After the reaction, add 200 mL of toluene to the reaction mixture solution, and filter the resulting suspension through Florisil (produced by Wacker Chemie AG, catalog number 540-00135), alumina, and Celite (produced by Wacker Chemie AG, catalog number 531-16855). Concentrate the obtained filtrate and purify it by silica gel column chromatography (developing solvent, toluene:hexane = 1:4). Concentrate the obtained fraction, and add acetone and methanol thereto. Irradiate the mixture with ultrasonic waves, and then perform recrystallization to obtain 3.2 g of the target white powder with a yield of 97%. The reaction scheme of the above synthesis method is shown in the following (J-6).

[0509] [Chemical formula 44]

[0510]

[0511] The Rf value of the target substance is 0.51, the Rf value of 9-(3-bromophenyl)-9-phenylfluorene is 0.62, and the Rf value of 4-phenyl-diphenylamine is 0.39. These measured values were obtained by silica gel column thin-layer chromatography (TLC) (developing solvent, ethyl acetate:hexane = 1:10).

[0512] Perform nuclear magnetic resonance ( 1 1H-NMR) measurement on the compound obtained in Step 2. The measurement data are shown below. Figure 45A and 45B show 1 1H-NMR spectra. The measurement results show that the fluorene derivative mBPAFLP (abbreviation) of the present invention represented by the structural formula (118) is obtained.

[0513] 1 1H-NMR (CDCl3, 300 MHz): δ (ppm) = 6.72 (d, J = 8.4, 1H), 6.92–7.36 (m, 22H), 7.40–7.44 (m, 4H), 7.54–7.57 (m, 2H), and 7.72–7.75 (m, 2H).

[0514] The molecular weight of the compound obtained in Step 2 was measured using a GC-MS detector (ITQ1100 ion trap GC / MS system, manufactured by Thermo Fisher). Accordingly, the main peak with a measured molecular weight of 561.3 (mode: EI+) was confirmed to obtain the target mBPAFLP (abbreviation).

[0515] The following tests were conducted on various physical properties of the obtained target substance mBPAFLP (abbreviation).

[0516] The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V-550, manufactured by JASCO Corporation) (measurement range: 200 nm - 800 nm). Figure 46 The absorption spectra of the toluene solution and the thin film are shown. The horizontal axis represents the wavelength (nm), and the vertical axis represents the absorption intensity (arbitrary unit). The toluene solution was placed in a quartz cell for measurement. The displayed spectrum was obtained by subtracting the absorption spectra of quartz and toluene from the absorption spectrum of the sample. The sample of the thin film evaporated on a quartz substrate was measured, and the displayed spectrum was obtained by subtracting the absorption spectrum of quartz from the absorption spectrum of the sample. From these spectra, for the case of the toluene solution, absorption peaks were observed at approximately 310 nm and 325 nm on the long wavelength side, and for the case of the thin film, absorption peaks were observed at approximately 312 nm and 329 nm on the long wavelength side.

[0517] The emission spectrum was measured using a fluorescence spectrophotometer (FS920, manufactured by Hamamatsu Photonics). Figure 47 The emission spectra of the toluene solution and the thin film are shown. The horizontal axis represents the wavelength (nm), and the vertical axis represents the emission intensity (arbitrary unit). The toluene solution was placed in a quartz cell for measurement, and for the thin film, the sample evaporated on a quartz substrate was measured. From these spectra, for the case of the toluene solution, the maximum emission wavelength was observed at 382 nm (excitation wavelength: 340 nm), and for the case of the thin film, the maximum emission wavelength was observed at 393 nm (excitation wavelength: 343 nm).

[0518] The results of measuring the thin film using a photoelectron spectrophotometer (AC-2, manufactured by Riken Keiki Co., Ltd) in this atmosphere showed that the HOMO energy level of the thin film was -5.73 eV. The Tauc curve of the thin film absorption spectrum showed that the absorption edge was 3.34 eV. Therefore, the energy gap in the solid state was approximately 3.34 eV, which indicates that the LUMO energy level of the thin film was -2.39 eV. This indicates that mBPAFLP (abbreviation) has a relatively deep HOMO energy level and a wide bandgap (Bg).

[0519] The oxidation-reduction reaction characteristics of mBPAFLP (abbreviation) were detected using cyclic voltammetry (CV) curves. It should be noted that measurements were carried out using an electrochemical analyzer (ALS model 600A or 600C, manufactured by BAS Inc.).

[0520] It should be noted that for the measurement of the oxidation reaction characteristics, the potential of the working electrode relative to the reference electrode was scanned from -0.38 V to 0.69 V and then from 0.69 V to 0.38 V. The HOMO energy level was found to be -5.53 [eV]. In addition, even after 100 cycles, the oxidation peak was still a similar value. Accordingly, the redox repetition process between the oxidized state and the neutral state was found to have favorable characteristics.

[0521] The melting point was measured. The melting point was 211 °C - 212 °C.

[0522] (Example 12)

[0523] In Example 12, the manufacturing method of a light-emitting element formed using the fluorene derivative 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP) synthesized in Example 1 and the test results of the element characteristics were described.

[0524] The element structure of the light-emitting element in Example 12 was as Figure 18 shown. The above-mentioned fluorene derivative (abbreviation: mBPAFLP) of the present invention was used for the hole injection layer and the hole transport layer to form the light-emitting element 14.

[0525] First, indium tin oxide containing silicon oxide was deposited on the substrate 1501 by sputtering to form the first electrode 1502. Note that the thickness of the first electrode 1502 was 110 nanometers and the electrode area was 2 mm × 2 mm.

[0526] Then, an EL layer 1503 including a plurality of layers stacked was formed on the first electrode 1502. In Example 9, the EL layer 1503 had a structure in which a first layer 1511 (hole injection layer), a second layer 1512 (hole transport layer), a third layer 1513 (light-emitting layer), a fourth layer 1514 (electron transport layer), and a fifth layer 1515 (electron injection layer) were stacked in sequence.

[0527] The substrate provided with the first electrode 1502 was fixed to the substrate jig of the vacuum evaporation apparatus with the surface provided with the first electrode 1502 facing downward. The pressure of the vacuum evaporation apparatus was reduced to about 10 -4Pa. Then, on the first electrode 1502, a hole injection material is deposited to a thickness of 50 nm to form the first layer 1511 (hole injection layer). When forming the light-emitting element 14, 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP) and molybdenum(VI) oxide are co-evaporated to form the first layer 1511 (hole injection layer 1511). The thickness is 50 nm, and the evaporation rate is controlled so that the weight ratio of mBPAFLP to molybdenum(VI) oxide is 4:2 = (mBPAFLP: molybdenum(VI) oxide). It should be noted that when forming the comparative light-emitting element 15, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) and molybdenum(VI) oxide are co-evaporated to form the first layer 1511 (hole injection layer 1511). The thickness is 50 nm, and the evaporation rate is controlled so that the weight ratio of NPB to molybdenum(VI) oxide is 4:2 = (NPB: molybdenum(VI) oxide).

[0528] Next, a hole transport material is deposited on the first layer 1511 to a thickness of 10 nm by resistive heating through evaporation to form the second layer 1512 (hole transport layer). It should be noted that the light-emitting element 14 is formed using 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), and the comparative light-emitting element 15 is formed using 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB).

[0529] Next, a third layer 1513 (light-emitting layer) is formed on the second layer 1512 by resistive heating through evaporation. A film with a thickness of 30 nm is formed as the third layer 1513 by co-evaporating 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA) and 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA). Here, the evaporation rate is controlled so that the weight ratio of CzPA to PCBAPA is 1:0.075 = (CzPA:PCBAPA).

[0530] In addition, on the third layer 1513, a film of tris(8-hydroxyquinoline)aluminum(III) (abbreviation: Alq) with a thickness of 10 nm is formed by resistive heating through evaporation, and a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nm is formed thereon, thereby forming the fourth layer 1514 (electron transport layer).

[0531] On the fourth layer 1514, a film of lithium fluoride (LiF) with a thickness of 1 nm is formed as the fifth layer 1515 (electron injection layer).

[0532] Finally, a 200-nm-thick aluminum film is formed by evaporation using resistance heating to form the second electrode 1504. In this way, the light-emitting element 14 and the comparative light-emitting element 15 are formed.

[0533] Note that the light-emitting element 14 to the comparative light-emitting element 15 are formed in the same steps except for the first layer 1511 and the second layer 1512.

[0534] The light-emitting element 14 and the comparative light-emitting element 15 thus obtained are sealed in a glove box in a nitrogen atmosphere to prevent contact with air. Then, their operating characteristics are measured. Note that the measurement is carried out at room temperature (the atmosphere is maintained at 25 °C).

[0535] Figure 48 Show the current density and luminance characteristics of the light-emitting element 14 and the comparative light-emitting element 15. Figure 49 Show the voltage and luminance characteristics of the light-emitting element 14 and the comparative light-emitting element 15. Figure 50 Show the luminance and current efficiency characteristics of the light-emitting element 14 and the comparative light-emitting element 15. In Figure 48 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents current density (mA / cm 2 ). In Figure 49 , the vertical axis represents luminance (cd / m 2 ), and the horizontal axis represents voltage (V). In Figure 50 , the vertical axis represents current efficiency (cd / A), and the horizontal axis represents luminance (cd / m 2 ). In addition, Table 11 shows the respective voltages, chromaticities, and current efficiencies of the light-emitting element 14 and the comparative light-emitting element 15 near 1000 cd / m 2 .

[0536] [Table 11]

[0537]

[0538] When the driving voltage of the light-emitting element 14 is 3.4 V, the luminance is 1100 cd / m 2The sum current value is 0.72 mA. It is found that the current efficiency of the light-emitting element 14 using mBPAFLP (abbreviation) for the second layer 1512 is higher than that of the comparative light-emitting element 15 using NPB for the second layer 1512. It should be understood that this is because the carrier balance of the light-emitting element 14 is improved compared with the comparative light-emitting element 15. It is considered that since the HOMO energy level of mBPAFLP (abbreviation) is close to the HOMO energy level of CzPA (abbreviation, the host material of the light-emitting layer) (compared with NPB), the hole injection property of mBPAFLP from the hole transport layer to the light-emitting layer is improved. In addition, it is considered that since mBPAFLP (abbreviation) has a high LUMO energy level (compared with NPB), the electron blocking property of mBPAFLP (abbreviation) from the light-emitting layer to the hole transport layer is improved. In addition, since mBPAFLP (abbreviation) has a wide bandgap (Bg) (compared with NPB), it is considered that the excitons generated in the third layer (light-emitting layer) 1513 will not transfer to the adjacent second layer 1512 (that is, there is no quenching) and are confined.

[0539] In addition, when continuous lighting tests were carried out on the light-emitting element 14 and the comparative light-emitting element 15 under continuous light emission at a constant current, the initial brightness was set to 1000 cd / m 2 (assuming 1000 cd / m 2 is 100%, and the vertical axis represents the relative brightness), after 280 hours, the light-emitting element 14 showed 80% of the initial brightness, and the comparative light-emitting element 15 showed 72% of the initial brightness. Therefore, the light-emitting element 14 and the comparative light-emitting element 15 have a long lifespan. Therefore, it is found that using mBPAFLP (abbreviation) of the present invention can obtain a light-emitting element with a long lifespan.

[0540] (Comparative Example 1)

[0541] The synthesis method of 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) used in Examples 3 to 5 is described in detail.

[0542] [Chemical Formula 45]

[0543]

[0544] The synthesis scheme of 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) is shown in the following (X-1).

[0545] [Chemical Formula 46]

[0546]

[0547] To a 300 mL three-necked flask, 7.8 g (12 mmol) of 9-(4-bromophenyl)-10-phenylanthracene, 4.8 g (12 mmol) of 4-(9-phenyl-9H-carbazol-3-yl)diphenylamine (abbreviation: PCBA), and 5.2 g (52 mmol) of sodium tert-butoxide were added, and the atmosphere in the flask was replaced with nitrogen. Then, 60 mL of toluene and 0.30 mL of tris(tert-butyl)phosphine (10 wt% hexane solution) were added to the mixture. After degassing the mixture while stirring under reduced pressure, 136 mg (0.24 mmol) of bis(dibenzylideneacetone)palladium(0) was added to the mixture. The mixture was stirred at 100 °C for 3 hours. After stirring, about 50 mL of toluene was added to the mixture. The mixture was filtered through Celite (produced by Wacker Chemie AG, catalog number 531-16855), alumina, and Florisil (produced by Wacker Chemie AG, catalog number 540-00135). The resulting filtrate was concentrated to obtain a yellow solid. The solid was recrystallized from toluene / hexane to obtain 6.6 g of a light yellow powdery solid PCBAPA, which is the target product of the synthesis, with a yield of 75%.

[0548] Then, by the method of train sublimation, 3.0 g of the obtained light yellow powdery solid was sublimated and purified. For the sublimation purification conditions, PCBAPA was heated at 350 °C under a pressure of 8.7 Pa and an argon gas flow rate of 3.0 mL / min. After sublimation purification, 2.7 g of a light yellow PCBAPA solid was obtained, with a yield of 90%.

[0549] The obtained compound was measured by nuclear magnetic resonance (NMR) method. The measurement data are shown below.

[0550] 1 1H-NMR (CDCl3, 300 MHz): δ (ppm) = 7.09–7.14 (m, 1H), 7.28–7.72 (m, 33H), 7.88 (d, J = 8.4 Hz, 2H), 8.19 (d, J = 7.2 Hz, 1H), and 8.37 (d, J = 1.5 Hz, 1H).

[0551] The measurement results indicate that 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) was obtained.

[0552] The light-emitting elements 1 - 5 described in the above examples can be formed using 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA).

[0553] (Comparative Example 2)

[0554] Describe in detail the synthesis method of 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II) used in Example 6 and Example 7.

[0555] [Chemical Formula 47]

[0556]

[0557] (Y-1) shows the synthesis scheme of 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II).

[0558] [Chemical Formula 48]

[0559]

[0560] Add 2.3 g (6.6 mmol) of 2-(4-iodophenyl)-5-phenyl-1,3,4-oxadiazole, 1.6 g (6.6 mmol) of 3-phenyl-9H-carbazole, and 1.4 g (15 mmol) of sodium tert-butoxide to a 100 mL three-necked flask, and displace the atmosphere in the flask with nitrogen. Add 30 mL of toluene and 0.2 mL of a 10 wt% hexane solution of tris(tert-butyl)phosphine to the mixture, degas the mixture by reducing the pressure in the flask with an aspirator, and then displace the atmosphere in the flask with nitrogen. Add 0.058 g (0.10 mmol) of bis(dibenzylideneacetone)palladium(0) to the mixture, and then stir in a nitrogen stream at 80 °C for 15 hours. After stirring, add toluene to the mixture, and wash the suspension successively with a saturated aqueous solution of sodium carbonate and saturated brine. Then, add magnesium sulfate to the organic layer to remove moisture. After that, filter the mixture by suction to obtain a filtrate. Filter the obtained filtrate through Celite (produced by Wacker Chemie AG, catalog number 531-16855) to obtain a filtrate. Purify the compound obtained by concentrating the filtrate by silica gel column chromatography. First, use toluene as the elution solvent, and then use a mixed solvent of toluene:ethyl acetate = 4:1 as the elution solvent for column chromatography. Add acetone to the solid obtained by concentrating the fraction, and wash with ultrasonic irradiation. Filter the compound by suction to collect the solid. Recrystallize the collected solid with a mixed solvent of chloroform and hexane to obtain 2.0 g of a powdery white solid with a yield of 64%.

[0561] Purify 1.1 g of the obtained light yellow powdery solid by sublimation through a multi-stage sublimation method. Sublimation purification is carried out at 240 °C for 16 hours under a reduced pressure of 3.0 Pa and an argon gas flow rate of 5 mL / min. In this way, 0.98 g of a white solid is obtained with a yield of 89%.

[0562] The obtained compound was measured by nuclear magnetic resonance (NMR). The measurement data are shown below.

[0563] 1 1H-NMR (CDCl3, 300 MHz): δ (ppm) = 7.30–7.76 (m, 13H), 7.79 (d, J = 8.3 Hz, 2H), 8.14–8.24 (m, 3H), 8.35 (sd, J = 1.5 Hz, 1H), and 8.39 (d, J = 8.8 Hz, 2H).

[0564] The measurement results showed that 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II) was obtained.

[0565] 3-Phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II) can be used to form the light-emitting elements 6 to 10 described in the above embodiments.

[0566] (Comparative Example 3)

[0567] The synthesis method of 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) used in Example 7 will be described in detail.

[0568] [Chemical Formula 49]

[0569]

[0570] The synthesis scheme of 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) is shown in (Z-1).

[0571] [Chemical Formula 50]

[0572]

[0573] In a 100 mL three-necked flask, 2.0 g (4.9 mmol) of 4-(9-phenyl-9H-carbazol-3-yl)diphenylamine, 1.1 g (4.9 mmol) of 4-bromobiphenyl, and 2.0 g (20 mmol) of sodium tert-butoxide were added, and the air in the flask was replaced with nitrogen. Then, 50 mL of toluene and 0.30 mL of tris(tert-butyl)phosphine (10 wt% hexane solution) were added to the mixture.

[0574] After stirring the mixture while degassing under reduced pressure, 0.10 g of bis(dibenzylideneacetone)palladium(0) was added to the mixture. The mixture was heated and stirred at 85 °C for 5 hours to react. After the reaction, toluene was added to the reaction mixture. The suspension was filtered through Celite (produced by Wacker Chemie AG, catalog number 531-16855), alumina, and Florisil (produced by Wacker Chemie AG, catalog number 540-00135) to obtain a filtrate. The obtained filtrate was washed successively with a saturated aqueous solution of sodium carbonate and saturated brine. Then, magnesium sulfate was added to the organic layer to remove water. After drying, the mixture was filtered to remove magnesium sulfate to obtain a filtrate.

[0575] The obtained filtrate was concentrated and purified by silica gel column chromatography. First, a mixed solvent of toluene:hexane = 1:9 was used as the elution solvent, and then a mixed solvent of toluene:hexane = 3:7 was used as another elution solvent for silica gel column chromatography. The solid obtained from the concentrated fraction was recrystallized with a mixed solvent of chloroform and hexane to obtain 2.3 g of a white powdery solid with a yield of 84%.

[0576] By a multi-stage sublimation method, 1.2 g of the obtained white powdery solid was sublimated and purified. Sublimation purification was carried out at 280 °C for 20 hours under a reduced pressure of 7.0 Pa and an argon gas flow rate of 3 mL / min. Thus, 1.1 g of a white solid was obtained with a yield of 89%.

[0577] The obtained compound was measured by nuclear magnetic resonance (NMR) method. The measurement data are shown below.

[0578] 1 1H-NMR (DMSO-d6, 300 MHz): δ (ppm) = 7.05–7.20 (m, 7H), 7.28–7.78 (m, 21H), 8.34 (d, J = 7.8 Hz, 1H), and 8.57 (s, 1H).

[0579] The measurement results indicated that 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) was obtained.

[0580] 4-Phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) can be used to form light-emitting elements 8 - 10.

[0581] (Comparative Example 4)

[0582] A more detailed description of another synthetic method for 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) used in Comparative Example 3 is provided. This synthetic method is preferred because the target substance with high purity can be easily obtained in high yield.

[0583] [Chemical Formula 51]

[0584]

[0585] [Step 1: Synthetic Method for 3-(4-Bromophenyl)-9-phenyl-9H-carbazole]

[0586] (Z-2) shows the synthetic scheme for 3-(4-bromophenyl)-9-phenyl-9H-carbazole.

[0587] [Chemical Formula 52]

[0588]

[0589] In a 300 mL three-necked flask, a mixture of 14 g (50 mmol) of 4-bromoiodobenzene, 14 g (50 mmol) of 9-phenyl-9H-carbazole-3-boronic acid, 110 mg (0.5 mmol) of palladium(II) acetate, 300 mg (1.0 mmol) of tris(o-tolyl)phosphine, 50 mL of toluene, 10 mL of ethanol, and 25 mL of aqueous potassium carbonate solution (2 mol / L) was stirred and degassed under reduced pressure, heated and stirred at 80 °C in a nitrogen atmosphere for 6 hours to carry out the reaction.

[0590] After the reaction, 200 mL of toluene was added to the reaction mixture solution, and the resulting suspension was filtered through Florisil (produced by Wacker Chemie AG, catalog number 540-00135) and Celite (produced by Wacker Chemie AG, catalog number 531-16855). The obtained filtrate was washed with water, and magnesium sulfate was added thereto to absorb moisture. The suspension was filtered to obtain a filtrate. The obtained filtrate was concentrated and purified by silica gel column chromatography. At this time, a mixed solvent of toluene and hexane (toluene:hexane = 1:4) was used as the elution solvent for chromatography. The concentrated fraction was concentrated, and hexane was added thereto. The mixture was irradiated with ultrasonic waves and then recrystallized to obtain 15 g of the target white powder with a yield of 75%.

[0591] The Rf value of the target substance is 0.32, and the Rf value of 4-bromoiodobenzene is 0.74. These measured values were obtained by silica gel column thin-layer chromatography (TLC) (elution solvent, ethyl acetate:hexane = 1:10).

[0592] In addition, the RF value of the by-product 1,4-bis(9-phenyl-9H-carbazol-3-yl)benzene was 0.23 (elution solvent, ethyl acetate:hexane = 1:10); however, spots could be slightly observed on TLC in the reaction suspension.

[0593] It should be understood that since the iodine moiety in 4-bromoiodobenzene (a dihalide and used as a source material) has a higher reactivity than the bromine moiety, it selectively (preferably) reacts with the boron compound 9-phenyl-9H-carbazol-3-ylboronic acid (i.e., the dihalide reacts with the boron compound almost in a 1:1 ratio). In addition, since the RF value of the target substance and that of the by-product have a sufficient difference, the target product and the by-product can be easily separated in the above chromatography.

[0594] The compound obtained in Step 1 was measured by nuclear magnetic resonance ( 1 1H-NMR). The measurement data are shown below.

[0595] 1 1H-NMR (CDCl3, 300 MHz): δ (ppm) = 7.24–7.32 (m, 1H), 7.40–7.64 (m, 13H), 8.17 (d, J = 7.2, 1H), and 8.29 (s, 1H).

[0596] The test results showed that the target substance 3-(4-bromophenyl)-9-phenyl-9H-carbazole was obtained.

[0597] The molecular weight of the above compound was measured using a GC-MS detector (ITQ1100 ion trap GC / MS system, manufactured by ThermoFisher Scientific K.K). Accordingly, the main peak with a molecular weight of 397.13 (mode: EI+) was measured, confirming the obtaining of the target substance 3-(4-bromophenyl)-9-phenyl-9H-carbazole.

[0598] The GC-MS detector detected the peak of the by-product 1,4-bis(9-phenyl-9H-carbazol-3-yl)benzene (molecular weight, 560.2). Therefore, it was confirmed that the target substance with high purity could be easily obtained in extremely high yield through the reaction of Step 1.

[0599] [Step 2: Synthesis method of 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP)]

[0600] The synthesis scheme of 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) is shown in (Z-3).

[0601] [Chemical formula 53]

[0602]

[0603] 4-Phenyl-diphenylamine and 3-(4-bromophenyl)-9-phenyl-9H-carbazole are heated and stirred in an organic solvent, and reacted using a palladium catalyst, a ligand of the palladium catalyst, and a base.

[0604] After the reaction, the reaction mixture solution is purified to obtain the target white powder.

[0605] The obtained compound is measured by nuclear magnetic resonance (NMR). The measurement results show that the target substance 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) obtained in Comparative Example 3 is confirmed.

[0606] As described above, it is confirmed that the target substance with high purity can be easily obtained in extremely high yield by the synthesis method described in Comparative Example 4.

[0607] This application is based on Japanese Patent Application No. 2009-131504 filed with the Japan Patent Office on May 29, 2009, the entire content of which is incorporated herein by reference.

[0608] Reference numerals

[0609] 101: Substrate, 102: First electrode, 103: EL layer, 104: Second electrode, 111: Layer

[0610] 112: layer, 113: layer, 114: layer, 115: layer, 301: electrode, 302: electrode, 303: EL layer, 304: EL layer, 305: charge generation layer, 401: source side drive circuit, 402: pixel portion, 403: gate side drive circuit, 404: sealing substrate, 405: sealant; 407: spacer, 408: wire, 409: flexible printed circuit (FPC), 410: component substrate, 411: switching TFT, 412: current control TFT, 413: first electrode; 414: insulator, 416: EL layer, 417: second electrode, 418: light emitting element, 423: n-channel TFT, 424: p-channel TFT, 501: substrate, 502: first electrode, 503: second electrode, 504: EL layer, 505: insulating layer, 506: separation layer, 511: first light emitting unit, 512: second light emitting unit, 513: charge generation layer, 521: first electrode, 522: second electrode, 611: housing, 612: support substrate, 613: display portion, 614: speaker portion, 615: video input terminal, 621: main body, 622: housing, 623: display portion, 624: keyboard, 625: external connection member, 626: pointing device, 631: main body, 632: housing, 633: display portion, 634: sound input portion, 635: sound output portion, 636: operation key, 637: external connection member, 638: antenna, 641: main body, 642: display portion, 643: housing, 644: external connection member, 645: remote control receiving portion, 646: image receiving portion, 647; battery, 648: sound input portion, 649: operation key, 650: eyepiece portion, 701: housing, 702: liquid crystal layer, 703: backlight, 704: housing, 705: driving IC, 706: terminal, 801: housing, 802: light source, 901: lighting device, 902: television receiver, 913: layer, 1501: substrate, 1502: first electrode, 1503: EL layer, 1504: second electrode, 1511: layer, 1512: layer, 1513: layer, 1514: layer, and 1515: layer.

Claims

1. A light-emitting element, comprising: a layer positioned between a pair of electrodes, wherein the layer contains a compound represented by the general formula (G1): Wherein: R 1 -R 8 independently represents a hydrogen atom; a 1 -[[-END]] a 4 each independently represents a substituted or unsubstituted phenylene group; Ar 1 and Ar 2 each independently represents an aryl group having 6 to 13 ring carbon atoms; Ar 3 represents any one of an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms substituted with any one of an alkyl group, a phenyl group, a biphenyl group, and a naphthyl group; When R 1 -R 8 , a 1 to a 4 Ar 1 Ar 2 Ar 3 has substituents, the substituents are alkyl or aryl; and J and k independently represent 1 ，m represent 0, and n represent 0 or 1.

2. A light-emitting element, comprising: a layer positioned between a pair of electrodes, wherein the layer contains a compound represented by the general formula (G1): Wherein: R 1 -R 8 each independently represents a hydrogen atom a 1 -[[]]END]] a 4 independently represents a substituted or unsubstituted phenylene group, Ar 1 represents an aryl group having 6 to 13 ring carbon atoms, Ar 2 represents any one of a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorene group, and a substituted or unsubstituted spirofluorene group. Ar 3 represents any one of an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms substituted by any one of an alkyl group, a phenyl group, a biphenyl group, and a naphthyl group; When R 1 -R 8 、 a 1 to a 4 、Ar 1 、Ar 2 、Ar 3 has substituents, the substituents are alkyl or aryl; and J and k independently represents 1 ，m represents 0, and n represents 0 or 1.

3. A light-emitting element, comprising: a layer positioned between a pair of electrodes, wherein the layer contains a compound represented by the general formula (G1): Wherein: R 1 -R 8 each independently represents a hydrogen atom a 1 -[[]] a a 4 represents a substituted or unsubstituted phenylene group Ar 1 represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted spiro-fluorenyl group Ar 2 represents any one of a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, and a substituted or unsubstituted spirofluorene group, Ar 3 represents any one of an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms substituted by any one of an alkyl group, a phenyl group, a biphenyl group, and a naphthyl group; When R 1 -R 8 、 a 1 to a 4 、Ar 1 、Ar 2 、Ar 3 has substituents, the substituents are alkyl or aryl; and J and k independently represent 1 ，m represent 0, and n represent 0 or 1.

4. The light-emitting element according to any one of claims 1 to 3, wherein a 1 - a 4 independently represents an unsubstituted phenylene group.

5. The light-emitting element according to any one of claims 1 to 3, wherein Ar 3 represents any one of structural formulas (Ar3-6) to (Ar3-8): 。 6. Use of a compound represented by the general formula (G1) in the manufacture of a light-emitting element: Wherein: R 1 -R 8 each independently represents a hydrogen atom; a 1 - a 4 each independently represents a substituted or unsubstituted phenylene group; Ar 1 and Ar 2 each independently represents an aryl group having 6 to 13 ring carbon atoms; Ar 3 represents any one of an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms substituted with any one of an alkyl group, a phenyl group, a biphenyl group, and a naphthyl group; When R 1 -R 8 、 a 1 to a 4 、Ar 1 、Ar 2 、Ar 3 has substituents, the substituents are alkyl or aryl; and J and k independently represent 1 ，m represent 0, and n represent 0 or 1.

7. Use of a compound represented by the general formula (G1) in the manufacture of a light-emitting element: Wherein: R 1 -R 8 each independently represents a hydrogen atom a 1 -[[]]END]] a 4 independently represents a substituted or unsubstituted phenylene group, Ar 1 represents an aryl group having 6 to 13 ring carbon atoms, Ar 2 represents any one of a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, and a substituted or unsubstituted spirofluorenyl group, Ar 3 represents any one of an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms substituted by any one of an alkyl group, a phenyl group, a biphenyl group, and a naphthyl group; When R 1 -R 8 、 a 1 to a 4 、Ar 1 、Ar 2 、Ar 3 has substituents, the substituents are alkyl or aryl; and J and k independently represent 1 ，m represent 0, and n represent 0 or 1.

8. Use of a compound represented by the general formula (G1) in the manufacture of a light-emitting element: Wherein: R 1 -R 8 each independently represents a hydrogen atom a 1 -[[]]END]] a 4 represents a substituted or unsubstituted phenylene group Ar 1 represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted spirofluorenyl group, Ar 2 represents any one of a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, and a substituted or unsubstituted spirofluorene group, Ar 3 represents any one of an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms substituted by any one of an alkyl group, a phenyl group, a biphenyl group, and a naphthyl group; When R 1 -R 8 、 a 1 to a 4 、Ar 1 、Ar 2 、Ar 3 has substituents, the substituents are alkyl or aryl; and J and k independently represent 1 ，m represent 0, and n represent 0 or 1.

9. The use according to any one of claims 6 to 8, wherein a 1 - a 4 independently represent unsubstituted phenylene groups.

10. Use according to any one of claims 6 to 8, wherein Ar 3 represents any one of structural formulas (Ar3-6) to (Ar3-8): 。

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