Fluorene derivative, light-emitting element, light-emitting device, electronic device and lighting device

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): wherein R 1 ‑R 8 independently represents any one of a hydrogen atom, an alkyl group having 1-6 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted biphenyl group. 1 ‑α 4 In addition, Ar1 and Ar2 independently represent any aryl group having 6-13 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. #imgabs0#

Description

[0001] This application is a divisional application of the PCT patent application with international application number PCT / JP2010 / 058854 filed on May 19, 2010, application number 201080025006.4 entering the Chinese national phase, and invention name “Fluorene derivatives, light-emitting elements, light-emitting devices, electronic devices and lighting devices”, which claims priority on 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 has been conducted on light-emitting devices that utilize electroluminescence. In the basic structure of such devices, a layer containing a luminescent substance is inserted between a pair of electrodes. By applying a voltage to the device, light is emitted from the luminescent substance.

[0004] Because these light-emitting elements are self-luminous, they are considered to offer advantages over liquid crystal displays in terms of high pixel visibility and the absence of a backlight, making them suitable for use as flat-panel display elements. Furthermore, they offer advantages in being thin and lightweight, and exhibiting extremely fast response speeds.

[0005] Furthermore, since such light-emitting elements can be formed into films, planar light emission can be easily achieved. This allows for the creation of large-area elements utilizing planar light emission. This is a property that is difficult to achieve with point light sources such as incandescent lamps and LEDs, or linear light sources such as fluorescent lamps. Therefore, such light-emitting elements are particularly effective as surface light sources in applications such as lighting.

[0006] Light-emitting elements that utilize electroluminescent properties can be broadly classified based on whether they utilize organic or inorganic compounds as the luminescent material. When an organic compound is used as the luminescent material, electrons and holes are injected from a pair of electrodes into a layer containing the luminescent organic compound by applying a voltage to the light-emitting element, thereby generating an electric current. Light is emitted when the charge carriers (electrons and holes) recombine and the electrons and holes of the organic compound return from an excited state to a ground state, where the electrons and holes are simultaneously generated in the organic molecules having the luminescent property.

[0007] Based on this mechanism, such a light-emitting element is called a current-excitation light-emitting element. It should be noted that the excited state produced by the organic compound can be a singlet excited state or a triplet excited state. 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 method of emitting light by recombining carriers excited by current, there is also a method of transferring excitation energy to another organic compound, thereby exciting the organic compound to provide light emission. In this element structure, the light-emitting material is diffused (doped) into the light-emitting layer of an ordinary organic EL. The main material refers to the material into which the light-emitting material is diffused, and the dopant refers to the material diffused into the main material. In order to solve the problem that when the concentration of organic molecules in organic molecules is high (concentration quenching), the light emission efficiency is low due to the occurrence of stacking interactions, it is beneficial to obtain high luminous efficiency by doping organic molecules into the main material and suppressing stacking. At the same time, the excitation energy of the current excitation is transferred from the main material excited by the current to the dopant, so that the dopant emits light.

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

[0010] Organic EL layers have multiple layers, and a carrier transport layer is typically positioned between the light-emitting layer and the electrode. One reason for this is that the carrier transport layer prevents excitation energy in the light-emitting layer from being quenched by energy transfer to the electrode. Furthermore, materials with higher excitation energy than the light-emitting layer (exciton-blocking materials) are preferably used in the carrier transport layer adjacent to the light-emitting layer to prevent excitation energy in the light-emitting layer from being transferred.

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

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

[0013] [References]

[0014] [Patent Document]

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

[0016] An object of one embodiment of the present invention is to provide a novel fluorene derivative as a substance having high hole-transporting properties. Another object is to provide a light-emitting element having high luminous efficiency by applying the novel fluorene derivative to a light-emitting element. Another object of one 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 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] Where R 1 -R 8 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. 1 -α 4 independently represents any substituted or unsubstituted arylene group having 6 to 12 carbon atoms. 1 and Ar 2 independently represents any 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.

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

[0022] [Chemical Formula 2]

[0023]

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

[0025] [Chemical Formula 3]

[0026]

[0027] In the above structure, Ar in the general formula (G1) 1 and Ar 2 independently represents any one of the structural formulas (Ar-1) to (Ar-6), Ar 3 Represents any one of 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] Another embodiment of the present invention is a light-emitting element including an EL layer between a pair of electrodes, wherein the EL layer includes at least a light-emitting layer and a hole-transporting layer, and the hole-transporting layer includes one or more of the above-mentioned fluorene derivatives.

[0040] Another embodiment of the present invention is a light-emitting device formed using the above-mentioned light-emitting element. Another embodiment of the present invention is an electronic device formed using the above-mentioned light-emitting device. Another embodiment of the present invention is a lighting device formed using the above-mentioned light-emitting device.

[0041] The light-emitting device of one embodiment of the present invention is a light-emitting device comprising the aforementioned light-emitting element and a control device, wherein the control device controls the 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 a lighting device). In addition, the light-emitting device includes any of 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 directly mounted on a light-emitting element by a chip on glass (Chip on Glass (COG)) method.

[0042] Furthermore, an electronic device used in a display portion in one embodiment of the light-emitting device of the present invention is also within the scope of the present invention. Therefore, an embodiment of the electronic device of the present invention includes a display portion, wherein the display portion is provided with the above-described light-emitting device.

[0043] Furthermore, a lighting device using an embodiment of the light emitting device of the present invention is also included in the scope of the present invention. Therefore, an embodiment of the lighting device of the present invention is provided with the above-described light emitting device.

[0044] Since the fluorene derivatives of the present invention have high hole-transporting properties, they can be mainly used in the hole-transporting layer of the EL layer of a light-emitting element. In addition, the fluorene derivatives of the present invention can be used to form a light-emitting element with high luminous efficiency by forming a light-emitting element with a hole-transporting layer.

[0045] At the same time, using this light-emitting element, a light-emitting device, an electronic device, and a lighting device having 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 It is 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine 1 H-NMR spectrum;

[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 13is a graph showing the CV test results of 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine;

[0059] Figure 14A and 14B It is 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine 1 H-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 graph showing the CV test results of 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine;

[0063] Figure 18 It is a figure which shows the light-emitting element in Example.

[0064] Figure 19 This is a characteristic diagram showing the current density and luminance of the comparative light-emitting element 1 and the light-emitting element 2.

[0065] Figure 20 1 is a characteristic diagram showing the voltage and luminance of the comparative light-emitting element 1 and the light-emitting element 2.

[0066] Figure 21 This is a characteristic diagram showing the luminance and current efficiency of the comparative light-emitting element 1 and the light-emitting element 2.

[0067] Figure 22 is a characteristic diagram showing the current density and brightness of the light-emitting element 3;

[0068] Figure 23 is a characteristic diagram showing the voltage and brightness of the light emitting element 3;

[0069] Figure 24 is a characteristic diagram showing the brightness and current efficiency of the light-emitting element 3;

[0070] Figure 25 is a diagram showing the reliability test results of light emitting element 3;

[0071] Figure 26 is a characteristic diagram showing the current density and brightness of light-emitting element 4 and light-emitting element 5;

[0072] Figure 27 is a characteristic diagram showing the voltage and brightness 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 luminance of light-emitting element 6 and comparative light-emitting element 7;

[0076] Figure 31 1 is a characteristic diagram showing the voltage and luminance of the light-emitting element 6 and the comparative light-emitting element 7.

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

[0078] Figure 33 is a diagram showing 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 element 8 to light-emitting element 10;

[0081] Figure 36 is a characteristic diagram showing the luminance 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 luminance of the light-emitting element 11 and the comparative light-emitting element 12;

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

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

[0086] Figure 41 is a diagram showing 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 the light emitting element 13;

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

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

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

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

[0092] Figure 47 is a graph 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 brightness of the light-emitting element 14 and the comparison 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 for Carrying Out the Invention

[0097] The following describes embodiments of the present invention 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 will readily appreciate that various modifications and improvements may be made without departing from the purpose and scope of the present invention. Therefore, the present invention is not limited to the following description of the embodiments.

[0098] (Implementation 1)

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

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

[0101] [Chemical Formula 9]

[0102]

[0103] Where R 1 -R 8independently 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. 1 -α 4 independently represents any substituted or unsubstituted arylene group having 6 to 12 carbon atoms. 1 and Ar 2 independently represents any 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 When there is a substituent, the substituent may be, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a pentyl group or a hexyl group, or an aryl group such as a phenyl group or a biphenyl group. Alternatively, the substituents may be linked to each other to form a ring (e.g., a biphenyl group and an Ar 1 or Ar 2 The fluorene group forms a ring (for 9,9′-spirofluorenyl), or the hexyl group forms a ring (for cyclohexyl).

[0105] It is considered that when an alkyl group is used in the general formula (G1), solubility in an organic solvent is improved; therefore, when an element is formed by a wet process using this material, the use of a material having an alkyl group enables easy production of the element, which is preferred.

[0106] For R in the general formula (G1) 1 to R 8 , can 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 in the general formula (G1) 1 to α 4 , which 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 , can be substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted fluorenyl, or substituted or unsubstituted aryl, such as spirofluorenyl. Specific structural formulas (Ar-1) to (Ar-6) are given. In the following (Ar-4), the biphenyl group and Ar 1 or Ar 2 The fluorenyl groups form a ring, namely 9,9′-spirofluorenyl.

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

[0114] [Chemical Formula 12]

[0115]

[0116] For Ar in the general formula (G1) 3 , can 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 formulae (100) to (123) or structural formulae (150) to (173) are given as specific examples of the fluorene derivative represented by general formula (G1), but 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 derivative according to the embodiment of the present invention. For example, the fluorene derivative represented by the general formula (G1) according to the embodiment of the present invention can be synthesized by the synthesis reaction described below. It should be noted that the synthesis method of the fluorene derivative according to the embodiment of the present invention is not limited to the following synthesis method.

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

[0138] As shown in Scheme (A-1), a 1-halogenobiphenyl derivative (a1) is lithiated or converted into a Grignard reagent, and then reacted with a benzoyl derivative (a2) for dehydroxylation (dehydroxilation), thereby obtaining a halogenated arylfluorene derivative (a3).

[0139] [Chemical Formula 22]

[0140]

[0141] The halogen-containing aryl compound in scheme (A-1) is activated, reacted with a benzoyl derivative to form a phenol derivative, and then dehydroxylated by acid addition to obtain a fluorene derivative.

[0142] Examples of activation include reactions using alkyl lithium reagents for lithiation or reactions using active magnesium to obtain Grignard reagents. Examples of alkyl lithiums include n-butyl lithium, tert-butyl lithium, and methyl lithium. Examples of acids include hydrochloric acid. Ethers such as diethyl ether or tetrahydrofuran (THF) can be used as dehydrating solvents.

[0143] As shown in Scheme (A-2), a diarylamine derivative (a6) can be obtained by coupling an aryl halide 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 its high reactivity.

[0150] In schemes (A-2) and (A-3), 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) can be carried out under various reaction conditions. As an example, a synthesis method using a metal catalyst in the presence of a base can be employed.

[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 include di(dibenzylideneacetone)palladium(0) and palladium acetate(II). Tri-tert-butylphosphine, tri-n-hexylphosphine, tricyclohexylphosphine, 1,1-bis(diphenylphosphino)ferrocene (abbreviation: DPPF), etc. 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, benzene, etc. 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 or argon.

[0152] The case of performing Ullmann reaction in schemes (A-2) and (A-3) is shown. A copper catalyst can be used as a metal catalyst, and copper iodide (I) and copper acetate (II) are given as copper catalysts. An inorganic base, such as potassium carbonate, is given as an example of a substance that can be used as a 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 and benzene are given as solvents that can be used in the above reaction. However, usable catalysts, ligands, bases and solvents are not limited thereto. In addition, the reaction is preferably carried out under an inert atmosphere such as nitrogen or argon.

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

[0154] <Synthesis Method 2 of Fluorene Derivative Represented by General Formula (G1)>

[0155] For example, as shown in Scheme (B-1), a halogenated arylfluorene 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 fluorene group-containing diarylamine derivative (b1) and a halogenated aromatic hydrocarbon derivative (a4) are coupled to obtain a fluorene derivative represented by the 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 It is a halogen, preferably bromine or iodine, and more preferably iodine due to its high reactivity.

[0162] In Schemes (B-1) and (B-2)+, 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) can be carried out under various reaction conditions. As an example, a synthesis method using a metal catalyst in the presence of a base can be employed.

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

[0164] <Synthesis Method 3 of Fluorene Derivative Represented by General Formula (G1)>

[0165] For example, as shown in Scheme (C-1), a halogenated arylfluorene derivative (c1) is lithiated or converted into a Grignard reagent and reacted with an organic boronic acid to obtain an arylboronic acid derivative (c2) having a fluorenyl group (note that J represents 1).

[0166] [Chemical Formula 27]

[0167]

[0168] As shown in Scheme (C-2), the triarylamine derivative (c3) is halogenated to give a halogenated triarylamine derivative (c4).

[0169] [Chemical Formula 28]

[0170]

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

[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 It is a halogen, preferably bromine or iodine, and more preferably iodine due to its high reactivity.

[0176] The reaction of obtaining an aromatic compound containing a boronic acid group (or an organic boron group) using an aromatic compound containing a halogen group in Scheme (C-1) has various reaction conditions. 1 to R 8 represents hydrogen or an alkyl group.

[0177] As an example of the reaction, after the aryl compound containing a halogen group is lithiated using an alkyl lithium reagent, a boron reagent is added to carry out boron oxidation or organoboration of the aryl compound containing a halogen group. n-Butyl lithium or methyl lithium etc. can be used as the alkyl lithium reagent. Trimethyl borate or isopropyl borate etc. can be used as the boron reagent. Ethers such as diethyl ether or tetrahydrofuran (THF) can be used as dehydrating solvents. Alternatively, a Grignard reagent with active magnesium can be used instead of a lithiating reagent.

[0178] The halogenation reaction in scheme (C-2) has a variety of reaction conditions. For example, the reaction using a halogenating agent in the presence of a polar solvent can be used. N-bromosuccinimide (abbreviation: NBS), N-iodosuccinimide (abbreviation: NIS), bromine, iodine or potassium iodide etc. can be used as a halogenating agent. Due to the low cost synthesis, bromine is preferably used as a halogenating agent. Iodine is preferably used as a halogenating agent, because when the reaction performed next uses the generated material as a source, the reaction can be more easily carried out (the part replaced by iodine has higher activity). It should be noted that k is 1 in scheme (C-2), and the halogenation reaction occurs specifically in the para position of the amine.

[0179] The coupling reaction of the aryl compound containing a halogen group and the aryl compound containing a boronic acid (arylboronic acid) in Scheme (C-3) can be carried out under various reaction conditions. As one 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 adopting Suzuki-Miyaura reaction is described. A palladium catalyst, such as a mixture of a palladium complex and its ligand, can be used as a metal catalyst. Palladium acetate (II), tetrakis (triphenylphosphine) palladium (0) and bis (triphenylphosphine) palladium dichloride (II) are given as palladium catalysts. Tri (o-tolyl) phosphine, triphenylphosphine and tricyclohexylphosphine are given as ligands. In addition, organic bases such as sodium tert-butoxide and inorganic bases such as potassium carbonate 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 ether such as ethylene glycol dimethyl ether and water can be used as a solvent. However, the catalysts, ligands, bases and solvents that can be used are not limited to these. Alternatively, in the above scheme, an organoboron compound such as an aryl derivative, arylaluminum, arylzirconium, arylzinc or aryltin compound may be used instead of the arylboronic acid. In addition, the reaction is preferably carried out under an inert atmosphere such as nitrogen or argon.

[0181] (Implementation Method 2)

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

[0183] The light-emitting element in Embodiment 2 includes a first electrode serving as an anode, a second electrode serving as a cathode, and an EL layer interposed between the first and second electrodes. Note that the light-emitting element in Embodiment 2 can emit light when a voltage is applied to each electrode so that the first electrode has a higher potential than the second electrode.

[0184] In addition, the EL layer of the light-emitting element in embodiment 2 includes 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) starting from the first electrode side.

[0185] Combine Figure 1A and 1B The structure of the light-emitting element in Embodiment 2 will be described. The substrate 101 serves as a support for the light-emitting element. For example, glass, quartz, or plastic can be used as the substrate 101.

[0186] It should be noted that although the above-mentioned substrate 101 can be retained in the product light-emitting device or electronic device using the light-emitting element of the embodiment of the present invention, the substrate 101 is only used as a support for the light-emitting element during the processing of the light-emitting element and is not retained in the terminal product.

[0187] For the first electrode 102 formed on the substrate 101, a metal, alloy, conductive compound, or mixture thereof having a high work function (specifically, a work function greater than or equal to 4.0 eV) is preferably used. Specific examples include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide (IZO), and indium oxide containing tungsten oxide and zinc oxide (IWZO). Other examples include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), and metal nitride materials (such as titanium nitride). 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 is conducive to hole injection, regardless of the work function of the first electrode 102, any known material can be used as long as the material can be used as an electrode material (for example, metals, alloys, conductive compounds and mixtures thereof, and elements belonging to Group 1 or Group 2 of the periodic table).

[0188] These materials are typically formed by sputtering. For example, an indium oxide-zinc oxide (IZO) film can be formed by sputtering using a target containing 1-20% by weight of zinc oxide added to indium oxide. An indium oxide film containing tungsten oxide and zinc oxide can be formed by sputtering using a target containing 0.5-5% by weight of tungsten oxide and 0.1-1% by weight of zinc oxide added to indium oxide. Alternatively, vacuum evaporation, coating, inkjet, or spin coating can be used.

[0189] Furthermore, in the EL layer 103 formed over the first electrode 102, when a composite material described below is used for the first layer 111 formed in contact with the first electrode 102, any of a variety of metals, alloys, conductive compounds, and mixtures thereof can be used as the material for the first electrode 102, regardless of the work function. For example, aluminum (Al), silver (Ag), and aluminum-containing alloys (AlSi) can also be used.

[0190] Alternatively, any element belonging to Groups 1 and 2 of the periodic table, i.e., 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 having a low work function can be used.

[0191] Note that when the first electrode 102 is formed using an alkali metal, an alkaline earth metal, or an alloy thereof, vacuum evaporation or sputtering can be used. Alternatively, when silver paste is used, a coating method or an inkjet method can be employed.

[0192] The EL layer 103 formed over the first electrode 102 can be formed using a known material, and a low-molecular compound or a high-molecular compound can be used. Note that the substance forming the EL layer 103 is not limited to an organic compound and may contain part of an inorganic compound.

[0193] The EL layer 103 is formed by stacking a hole injection layer containing a substance with a high hole injection property, a hole transport layer containing a substance with a high hole transport property, a light-emitting layer containing a light-emitting substance, an electron transport layer containing a substance with a high electron transport property, and an electron injection layer containing a substance with a high electron injection property in appropriate combinations.

[0194] It should be noted that Figure 1A The EL layer 103 shown includes 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 stacked in this order from the first electrode 102 side.

[0195] The first layer 111 (hole injection layer) is a hole injection layer containing a substance having a high hole injection property. As a 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, or manganese oxide can be used. Alternatively, a phthalocyanine-based compound such as phthalocyanine (abbreviation: H2Pc) or copper (II) phthalocyanine (abbreviation: CuPc) or vanadyl phthalocyanine (abbreviation: VOPc) can be used as a low molecular weight 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, as examples of low molecular weight organic compounds, there are 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:

[0014] Examples of the present invention include 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (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-di[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). Note that the carbazole derivatives of the present invention described in Embodiment 1 can also be used in a similar manner.

[0197] Alternatively, any polymer compound (e.g., an oligomer, a dendrimer, or a polymer) may be used. Examples of the polymer 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), and poly[N,N′-di(4-butylphenyl)-N,N′-di(phenyl)benzidine] (abbreviation: poly-TPD). Alternatively, a polymer compound to which an acid is added may 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 an acceptor substance into a substance having high hole transport properties can be used for the first layer 111. By using such a high hole transport substance containing an acceptor 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 acceptor properties. It should be noted that in this specification, the term "composite" not only refers to a state in which two materials are simply mixed, but also refers to a state in which 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 high molecular weight compounds (e.g., oligomers, dendrimers or polymers). The organic compound for the composite material preferably has a high hole transport property. Specifically, it is preferred to use an organic compound with a hole mobility greater than or equal to 10 -6 cm 2 However, any substance other than the above substances can be used as long as it is a substance with higher hole transport properties than electron transport properties. Specific examples of organic compounds that can be used for the composite material are as follows.

[0200] For example, as organic compounds 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, the aromatic hydrocarbon compounds include, for example, 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-di(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-di(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-di(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 9,10-di[2-(1-naphthyl)phenyl)-2-tert-butylanthracene, 9,10-di[2-(1-naphthyl)phenyl]anthracene and 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene.

[0202] In addition, aromatic hydrocarbon compounds include 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthracene, 10,10'-diphenyl-9,9'-bianthracene, 10,10'-di(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-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA).

[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, as well as transition metal oxides, can be given. In addition, there are oxides of metals from Groups 4 to 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 it is stable in air and has low hygroscopicity, making it easy to handle.

[0204] It should be noted that 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 for the first layer 111. It should be noted that a composite material formed by combining the carbazole compound according to 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-transporting layer containing a substance having high hole-transporting properties. It should be noted that the fluorene derivatives of the embodiment of the present invention described in Embodiment 1 can also be used for the second layer 112 in Embodiment 2. Because the fluorene derivatives of the embodiment of the present invention have a wide bandgap, the second layer 112 formed using these fluorene derivatives is less likely to absorb the excitation energy generated in the third layer (light-emitting layer) 113 adjacent to the second layer 112, and the excitons are effectively confined in the light-emitting layer. This results in a highly efficient light-emitting element.

[0206] Alternatively, the fluorene derivative of the embodiment 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, element formation can be facilitated and material utilization efficiency can be improved. Furthermore, since the energy diagrams of the first layer 111 and the second layer 112 are identical or similar, carriers can be easily transferred between the first layer 111 and the second layer 112.

[0207] The third layer 113 is a layer containing a substance having a high light-emitting property. A low-molecular organic compound described below can be used for the third layer 113. Note 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 substance, 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, for example, light-emitting substances that emit blue light include N,N'-di[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), etc.

[0210] The green light emitting substances include N-(9,10-diphenyl-2-anthracenyl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-di(1,1′-biphenyl-2-yl)-2-anthracenyl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthracenyl)-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2D PAPA), N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthracenyl]-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] Luminescent substances that emit yellow light include rubrene and 5,12-bis(1,1′-biphenyl-4-yl)-6,11-diphenyltetracene (BPT). Examples of luminescent substances that emit red light include N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (p-mPhTD) and 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (p-mPhAFD).

[0212] Phosphorescent compounds that can be used as the light-emitting layer 113 include, for example, tetrakis(1-pyrazolyl)boronic acid bis[2-(4′,6′-difluorophenyl)pyridine-N,C 2′ ]iridium(III) (abbreviation: FIr6), bis[2-(4′,6′-difluorophenyl)pyridine-N,C 2′ ] iridium (III) (abbreviation: FIrpic), picolinic acid di{2-[3′,5′-bis(trifluoromethyl)phenyl]pyridine-N,C 2 '} iridium (III) complex (abbreviation: Ir(CF3ppy)2(pic)) or bis[2-(4′,6′-difluorophenyl)pyridine-N,C 2 '] iridium (III) (abbreviation: FIr (acac)) and the like. The substances used for green light emission are tris (2-phenylpyridine-N, C 2′ )iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinium-N,C-acetylacetonate) 2′)iridium(III) (abbreviation: Ir(ppy)2(acac)), bis(1,2-diphenyl-1H-benzimidazole)iridium(III) acetylacetonate (abbreviation: Ir(pbi)2(acac)), or bis(benzo[h]quinolinol)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)). Substances used 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'-(pentafluorophenylphenyl)pyridinium]iridium (III) acetylacetonate (abbreviation: Ir(p-PF-ph)2(acac)), or bis(2-phenylbenzothiazole-N,C 2 ') iridium (III) (abbreviation: Ir (bt) 2 (acac)) and the like. The substances used for orange light emission are tris (2-phenylquinoline-N, C 2 ') iridium (III) (abbreviation: Ir(pq)3), or bis(2-phenylquinolinyl-N,C-acetylacetonate) 2 ') iridium (III) (abbreviation: Ir (pq) 2 (acac)) and the like. Substances used for red light emission are organic metal complexes, for example, acetylacetonatobis [2- (2'-benzo [4,5-a] thienyl) pyridine acid-N, C 3 ') Iridium (III) (abbreviation: Ir(btp)2(acac)), bis(1-phenylisoquinolinate-N,C 2 ') iridium (III) (abbreviation: Ir(piq)2(acac), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxaline]iridium (III) (abbreviation: Ir(Fdpq)2(acac)) or 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphinate platinum (II) (abbreviation: PtOEP), etc. In addition, rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium (III) (abbreviation: Tb(acac)3(Ph en)), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: Eu(DBM)3(Phen)) or tris[1-(2-thiophenoyl)-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); therefore, 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 luminescent 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, known substances can be used as dispersed substances (host materials) with luminescent properties. It is preferred to use a substance whose lowest unoccupied molecular orbital energy level (LUMO energy level) is shallower than the luminescent substance (smaller absolute value) and whose highest occupied molecular orbital energy level (HOMO energy level) is deeper than the luminescent substance (larger absolute value). In addition, it is preferred that the energy gap (band gap) (Bg: the difference between the HOMO energy level and the LUMO energy level) of the host material is greater than the Bg of the dopant with luminescent 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-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]-quinolinolato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolate)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviation: ZnPBO) or bis[2-(2-benzothiazolyl)phenolate]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-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 9,10-di(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9′-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) can also be used.

[0217] A variety of substances can be used as the dispersed substance with luminescent properties. For example, in order to suppress crystallization, a substance that suppresses crystallization, such as rubrene, can be further added. In addition, NPB or Alq, etc. can be further added to effectively transfer energy to the substance with luminescent properties. It should be noted that the fluorene derivative of the embodiment of the present invention described in Embodiment Mode 1 can be used. By using a structure in which a substance with high luminescent properties is dispersed in another substance, crystallization of the third layer 113 can be suppressed. In addition, concentration quenching caused by a high concentration of a substance with high luminescent properties can also be suppressed.

[0218] Among the above substances, it is particularly preferable to use a substance having an electron-transporting property, in which a substance having a light-emitting property is dispersed, to form the third layer 113. Specifically, any of the above metal complexes and heterocyclic compounds can be used; CzPA, DNA, and t-BuDNA among the above fused aromatic compounds can also be used; and larger molecular weight compounds will be described below as substances that can be used for the fourth layer 114.

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

[0220] The luminescent materials used 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′-di-(p-butylphenyl)-1,4-phenylenediamine]} copolymer (abbreviation: TAB-PFH), etc.

[0221] Luminescent materials used for green light emission include poly(p-phenylene vinylene) (abbreviation: PPV), [(9,9-dihexylfluorene-2,7-dimer)-(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] The luminescent materials used for orange to red light emission include poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (abbreviation: MEH-PPV), poly(3-butylthiophene-2,5-diyl) (abbreviation: R 4 -PAT), {[9,9-dihexyl-2,7-bis(1-cyanovinylene)fluorenyl]-[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 may be a stack of two or more layers. For example, when the first light-emitting layer and the second light-emitting layer are stacked sequentially from the hole transport layer side to form the light-emitting layer 113, the first light-emitting layer may be formed using a substance having hole transport properties as the main material, and the second light-emitting layer may be formed using a substance having electron transport properties as the main material. More preferably, a material having a hole transport property greater than an electron transport property is used as the main material for the first light-emitting layer, and a material having an electron transport property greater than a hole transport property is used as the main material for the second light-emitting layer. With the above structure, a light-emitting site is formed between the first light-emitting layer and the second light-emitting layer, thereby obtaining a more efficient element.

[0224] When the light-emitting layer having the above structure is formed using a plurality of materials, the light-emitting layer may be formed by co-evaporation using a vacuum evaporation method; or by using an inkjet method, a spin coating method, a dip coating method, or the like as a method of mixing a solution.

[0225] The fourth layer 114 is an electron transport layer containing a substance having high electron transport properties. For example, for the fourth layer 114, a metal complex such as Alq, Almq3, BeBq2, BAlq, Znq, ZnPBO, or ZnBTZ can be used as a low molecular weight organic compound. Alternatively, a heterocyclic compound such as PBD, OXD-7, TAZ, TPBI, BPhen, or BCP can be used instead of the metal complex. The substances mentioned here are mainly those with an electron mobility greater than or equal to 10 -6 cm2 / Vs. Note that any substance other than the above substances can 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 stack of two or more layers formed of the above substances.

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

[0227] The fifth layer 115 is an electron injection layer containing a substance having a high electron injection property. For the fifth layer 115, an alkali metal, an alkaline earth metal, or a compound thereof, 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 a compound thereof can be used. Specifically, an Alq layer containing magnesium (Mg) can be used. It should be noted that in this case, electrons can be injected more efficiently from the second electrode 104.

[0228] For the second electrode 104, a metal, alloy, conductive compound, or mixture thereof having a low work function (specifically, a work function of 3.8 eV or less) can be used. Specific examples of such cathode materials include elements belonging to Groups 1 and 2 of the periodic table, i.e., 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, and the like.

[0229] Note that when the second electrode 104 is formed using an alkali metal, an alkaline earth metal, or an alloy thereof, vacuum evaporation or sputtering can be used. When silver paste or the like is used, a coating method or an inkjet method can be employed.

[0230] Note that by providing the fifth layer 115, any of a variety of conductive materials, such as Al, Ag, ITO, and indium oxide-tin oxide containing silicon or silicon oxide, can be used to form the second electrode 104, regardless of the work function. Such a conductive material film can be formed by a method such as sputtering, inkjet coating, or spin coating.

[0231] Furthermore, 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 sequentially stacked, can be formed by any of a variety of methods, regardless of whether the method is a dry method or a wet method. For example, vacuum evaporation, inkjet, spin coating, and the like can be used. It should be noted that a different formation method can be used for each layer.

[0232] The second electrode 104 may be formed by a wet method (eg, a sol-gel method using a metal paste) instead of a dry method (eg, a sputtering method or a vacuum evaporation method).

[0233] Since holes generally 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 functions in the case of metals) are preferably the same or nearly the same, thereby reducing the carrier injection barrier between adjacent layers. Similarly, electrons generally 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. Their LUMO energy levels (work functions in the case of metals) are preferably the same or nearly the same, thereby reducing the carrier injection barrier between adjacent layers. The difference is preferably less than or equal to 0.2 eV, and more preferably less than or equal to 0.1 eV.

[0234] It is preferred that the difference in HOMO energy level between the second layer (hole transport layer) 112 and the third layer (light-emitting layer) 113 and the difference in LUMO energy level between the third layer (light-emitting layer) 113 and the fourth layer (electron transport layer) 114 be increased to confine carriers in the light-emitting layer, thereby obtaining a more efficient light-emitting element. It should be noted that in this case, when the potential 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-described light-emitting element of this light-emitting embodiment, a potential difference is generated between the first electrode 102 and the second electrode 104, and holes and electrons recombine in the EL layer 103, resulting in current flow and light emission. The emitted light is then 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 a light-transmitting property.

[0236] like Figure 2A As shown, when only the first electrode 102 has a light-emitting property, the emitted light is extracted from the substrate side through the first electrode 102. Alternatively, as shown in FIG. Figure 2B As shown, when only the second electrode 104 has a light-emitting property, the emitted light is extracted from the side opposite to the substrate 101 through the second electrode 104. Figure 2C As shown, when the first electrode 102 and the second electrode 104 each have a light-emitting property, emitted light is extracted from the substrate 101 side and the side opposite to the substrate 101 simultaneously 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 may be employed as long as it includes at least the second layer 112 (hole transport layer) and the third layer 113 (light-emitting layer).

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

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

[0240] It should be noted that when manufacturing an active-matrix light-emitting device, there are no particular restrictions on the structure of the TFT. For example, a staggered TFT or an inverted staggered TFT can be used as appropriate. In addition, the driver circuit formed on the TFT substrate can be formed using both n-type and p-type TFTs or using only one of n-type or p-type TFTs. Furthermore, there are no particular restrictions on the crystallinity of the semiconductor film used in the TFT. An amorphous semiconductor film 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 efficiency of the element be improved but also power consumption can be reduced.

[0242] (Implementation 3)

[0243] See also Figure 3A and 3BIn Embodiment 3, a mode of a light-emitting element (hereinafter referred to as a stacked element) having a structure with 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 structures of the respective 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] exist Figure 3A In the embodiment, the first light-emitting unit 511 and the second light-emitting unit 512 are stacked together between the first electrode 521 and the second electrode 522. The first electrode 521 and the second electrode 522 can be similar to those in Embodiment 2. The first light-emitting unit 511 and the second light-emitting unit 512 can have the same or different structures, and a structure similar to that described in Embodiment 2 can 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 from one side into the light-emitting unit and injects holes from the other side into the light-emitting unit. The charge generation layer 513 may have a single-layer structure or a stacked structure of multiple layers. For a stacked structure of multiple layers, a structure in which a layer for injecting holes and a layer for injecting electrons are stacked is preferred.

[0246] For the layer for injecting holes, semiconductors or insulators such as molybdenum oxide, vanadium oxide, rhenium oxide or ruthenium oxide can be used. Alternatively, the layer for injecting holes can have a structure in which an acceptor substance is added to a substance with high hole transport properties. The layer comprising a substance with high hole transport properties and an acceptor substance comprises 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinoline dimethane (abbreviation: F4-TCNQ) or a metal oxide such as vanadium oxide, molybdenum oxide or tungsten oxide. For substances with high hole transport properties, a variety of compounds such as aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, high molecular weight compounds, oligomers, dendrimers and polymers can be used. It should be noted that the fluorene derivatives of the embodiment of the present invention described in embodiment 1 can also be used in a similar manner. It should be noted that it is preferred to use a material with a hole mobility greater than or equal to 10 -6 cm 2 As a substance with high hole transport properties, a substance with a specific hole transport property of 1 / 4Vs can be used. However, any substance other than the above substances can be used as long as it is a substance with higher hole transport properties than electron transport properties. Since the composite material of the substance with high hole transport properties and the acceptor substance has good carrier injection properties and good carrier transport properties, low voltage drive and low current drive 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 with high hole transport properties. As donor substances, alkali metals, alkaline earth metals, rare earth metals, metals 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 or cesium carbonate, etc. are preferably used. Alternatively, an organic compound such as tetrathiafulvalene can be used as a donor substance. The material described in embodiment 1 can be used as a substance with high electron transport properties. It should be noted that it is preferred to use a material with a hole mobility greater than or equal to 10 -6 cm 2 As a substance with high hole transport properties, a substance with a density of 1 / 4 Vs can be used. However, any substance other than the above substances can be used as long as it is a substance with higher electron transport properties than hole transport properties. Since the composite material of the substance with high hole transport properties and the donor substance has good carrier injection properties and good carrier transport properties, low voltage drive and low current drive can be achieved.

[0248] Alternatively, the electrode materials described in Embodiment 2 can be used for the charge generation layer 513. For example, the charge generation layer 513 can be formed by combining a layer containing a substance having a high hole-transporting property and a metal oxide with a transparent conductive film. In consideration of light extraction efficiency, the charge generation layer 513 is preferably a highly light-transmitting layer.

[0249] In any case, the charge generation layer 513 disposed between the first light-emitting unit 511 and the second light-emitting unit 512 is acceptable as long as it is a layer capable of injecting charges into the light-emitting unit from one side and injecting 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 such 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 also be similarly used, such as Figure 3BAs shown. By providing a plurality of light-emitting units in the light-emitting element of embodiment 3, wherein the light-emitting units are separated by the charge generation layer 513 between the paired electrodes, light emission in a high-brightness area can be achieved while maintaining a low current density, thereby achieving long-life light emission. When the light-emitting element is used in a light-emitting device as an example of an application, the voltage drop caused by the resistance of the electrode material can be reduced, thereby achieving uniform light emission over a large area. In addition, a light-emitting device with low power consumption that can be driven at a low voltage can be realized.

[0251] The light-emitting units emit light of different colors, so that the entire light-emitting element emits light of the desired color. For example, in a light-emitting element having two light-emitting units, the light emitted by the first light-emitting unit and the second light-emitting unit are made complementary, so that the light-emitting element as a whole can obtain a light-emitting element that emits white light. It should be noted that the word "complementary" refers to the color relationship in the achromatic colors obtained when the colors are mixed. In other words, white light can be obtained by mixing the light emitted by some substances as complementary colors. 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 as a whole provides white light emission.

[0252] It should be noted that this embodiment mode 3 can be combined with any other embodiment modes as appropriate.

[0253] (Implementation 4)

[0254] In the fourth embodiment, reference is made to Figure 4A and 4B A light-emitting device including the light-emitting element of the present invention in a pixel portion is described. Figure 4A is a top view of the light emitting device. Figure 4B It is along Figure 4A Cross-sectional view of the straight lines A-A' and BB'.

[0255] exist Figure 4A 4, reference numeral 401 denotes a driver circuit portion (source-side driver circuit), reference numeral 402 denotes a pixel portion, and reference numeral 403 denotes a driver circuit portion (gate-side driver circuit), which are indicated by dotted lines. Reference numeral 404 denotes a sealing substrate, reference numeral 405 denotes a sealing material, and the portion surrounded by sealing material 405 is space 407.

[0256] It should be noted that the lead 408 is used to transmit signals, input the signals to the source side driver circuit 401 and the gate side driver circuit 403, and receive image signals, clock signals, start signals, reset signals, etc. from the flexible printed circuit (FPC) 409, which 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 with an FPC or PWB connected thereto.

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

[0258] The pixel portion 402 includes a plurality of pixels including 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 an end portion of the first electrode 413.

[0259] To improve coverage, insulator 414 is preferably formed so that the upper or lower end of insulator 414 has a curved surface with a certain curvature. For example, when positive photosensitive acrylic resin is used as the material for insulator 414, a curved surface with a certain curvature radius (0.2-3 microns) is formed only at the upper end of insulator 414. Alternatively, insulator 414 can be formed using a negative photosensitive material that becomes insoluble in an etchant upon exposure to light, or a positive photosensitive material that becomes soluble in an etchant upon exposure to light.

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

[0261] The EL layer 416 can be formed by any of various methods, for example, an evaporation method using an evaporation mask, an inkjet method, and a spin coating method. The EL layer 416 may have any of the structures described in Embodiment Mode 2. Furthermore, as another material included in the EL layer 416, a low molecular weight compound or a high molecular weight compound (including an oligomer and a dendrimer) can be used. As the material for the EL layer, not only organic compounds but also inorganic compounds can be used.

[0262] The second electrode 417 can be formed using any of a variety of metals, alloys, and conductive compounds, or mixtures thereof. Among such materials, when the second electrode 417 is used as a cathode, metals, alloys, and conductive compounds, or mixtures thereof, having a low work function (work function less than or equal to 3.8 eV), are preferably used. Examples include elements of Group 1 or 2 of the periodic table, i.e., 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 these (e.g., MgAg and AlLi).

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

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

[0265] Note that an epoxy resin is preferably used as the sealant 405. The material used for this purpose is preferably a material that is impermeable to moisture and oxygen. As the material forming the sealing substrate 404, a glass substrate, a quartz substrate, or a plastic substrate composed of glass fiber reinforced plastic (FRP), polyvinyl fluoride (PVF), polyester, acrylic material, etc. can be used.

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

[0267] Furthermore, the light-emitting element of the present invention can be used for a passive matrix light-emitting device instead of the above-mentioned active matrix light-emitting device. Figure 5A and 5B A perspective view and a cross-sectional view showing a passive matrix light-emitting device using the light-emitting element of the present invention. Figure 5A is a perspective view of a light emitting device, Figure 5B It is along Figure 5A XY cross-sectional view.

[0268] exist Figure 5A and 5B In the embodiment, an EL layer 504 is provided between a first electrode 502 and a second electrode 503 on a substrate 501. The end of the first electrode 502 is covered by an insulating layer 505. Moreover, a separation layer 506 is provided on the insulating layer 505. The side walls of the separation layer 506 are inclined so that the distance between the two side walls gradually narrows toward the surface of the substrate. In other words, the cross section of the separation layer 506 along the narrow side is a trapezoid, and the length of the bottom side (the side in contact with the insulating layer 505, which is one of a pair of parallel sides of the trapezoidal cross section) is less than the length of the top side (the side not in contact with the insulating layer 505, which is the other side of a pair of parallel sides). A separation layer 506 in this manner can prevent defects in the light-emitting element due to static charge and the like.

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

[0270] Note 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 light-emitting efficiency, so a light-emitting device with low power consumption can be obtained.

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

[0272] (Implementation 5)

[0273] In the embodiment mode, an electronic device including the light-emitting device of the present invention described in embodiment mode 4 is described. Examples of the electronic device include: cameras such as video cameras and digital cameras; glasses-type displays, navigation systems, sound playback devices (such as car audio stereo systems or audio stereo devices), computers, game consoles, portable information terminals (such as mobile computers, mobile phones, portable game consoles, e-book readers, etc.), image reproduction devices equipped with recording media (specifically, devices capable of reproducing recording media such as digital versatile disks (DVDs) and equipped with a display device capable of displaying images), etc. Specific examples of these electronic devices are shown in FIG. Figures 6A-6D middle.

[0274] Figure 6A A television receiver according to one 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, and the like. 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 characteristic 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 A computer according to an embodiment of the present invention is shown, which includes a main body 621, a housing 622, a display portion 623, a keyboard 624, an external connection port 625, a pointing device 626, and the like. In this computer, the light-emitting device of the present invention can be applied to the display portion 623. Since the light-emitting element of the present invention has a 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 A mobile phone according to one embodiment of the present invention is shown, and includes a main body 631, a housing 632, a display portion 633, a sound input portion 634, a sound output portion 635, operation keys 636, an external connection port 637, an antenna 638, and the like. In this mobile phone, the light-emitting device of the present invention can be applied to the display portion 633. Since the light-emitting element of the present invention has a 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 A video camera according to this embodiment is shown, which includes a main body 641, a display portion 642, a housing 643, an external connection port 644, a remote control receiving portion 645, an image receiving portion 646, a battery 647, a sound input portion 648, operation keys 649, an eyepiece portion 650, and the like. In this video camera, the light-emitting device of the present invention can be applied to the display portion 642. Since the light-emitting element of the present invention has a characteristic of high emission efficiency, a video camera with low power consumption can be obtained by using the light-emitting device of the present invention.

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

[0279] Furthermore, 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 in which the light-emitting device of the present invention is used as a backlight is shown. Figure 7 The liquid crystal display device shown in FIG. 7 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 a backlight for the aforementioned liquid crystal display, a low-power backlight can be obtained. Furthermore, since the light-emitting device of the present invention is a surface-emitting device, it can be formed over a large area, thereby also providing a large-area backlight. Consequently, a large-area liquid crystal display with low power consumption can be obtained.

[0281] Figure 8 This is an example of a desk lamp using the light emitting device of the present invention as a lighting device. Figure 8 The desk lamp shown in FIG. 8 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 the light emitting device can be used as a desk lamp with low power consumption.

[0282] Figure 9 An example of using the light emitting device of the present invention as an interior lighting system 901 is shown. Since the light emitting device of the present invention can be enlarged, it 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 the light emitting device can be used as a low-power lighting device. In a room where the light emitting device of the present invention is used as an interior lighting device 901, it can be placed Figure 6A The television receiver 902 of the present invention is shown, where public broadcasts or movies can be enjoyed.

[0283] Note that in Embodiment Mode 5, an appropriate combination of the structures described in Embodiment Modes 1 to 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 in an embodiment of the present invention is described. Specifically, a method for synthesizing 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 of 9-(4-bromophenyl)-9-phenylfluorene]

[0290] In a 100 ml three-necked flask, 1.2 g (50 mmol) of magnesium was heated and stirred under reduced pressure for 30 minutes to activate it. After the flask was cooled to room temperature, under a nitrogen atmosphere, a few drops of methylene bromide were added to determine the formation of foam and the generation of heat. 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 for 2.5 hours to obtain a Grignard reagent.

[0291] In a 500 ml three-necked flask, 10 g (40 mmol) of 4-bromobenzophenone and 100 ml of diethyl ether were placed, and the previously synthesized Grignard reagent was slowly added dropwise to the mixture, followed by heating and stirring under reflux for 9 hours.

[0292] After the reaction, the mixture was filtered to obtain a residue. The residue was dissolved in 150 ml of ethyl acetate, and 1N hydrochloric acid solution was added until the mixture became acidic. The mixture was stirred for 2 hours. The organic layer of the solution was washed with water. Magnesium sulfate was then added to remove moisture. The suspension was filtered, and the resulting 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 stirred at 130° C. for 1.5 hours under a nitrogen atmosphere to carry out a reaction.

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

[0295] [Chemical Formula 31]

[0296]

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

[0298] To a 100 ml three-necked flask were added 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), and the atmosphere in the flask was replaced with nitrogen. 20 ml of anhydrous xylene was then added to the mixture. After degassing the mixture while stirring under reduced pressure, 0.2 ml (0.1 mmol) of tri(tert-butyl)phosphine (10 wt% hexane solution) was added to the mixture. The mixture was heated and stirred at 110° C. in a nitrogen atmosphere for 2 hours to allow the reaction to proceed.

[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 resulting fraction was concentrated, and acetone and methanol were added thereto. The mixture was irradiated with ultrasound and then recrystallized to obtain 4.1 g of the target white powder with a yield of 92%. The reaction scheme of the above-mentioned synthesis method is shown below (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, which were measured by silica gel column thin layer chromatography (TLC) (elution solvent, ethyl acetate:hexane=1:10).

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

[0304] 1H-NMR (CDCl3, 300MHz): 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 performed 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) (measuring range: 200 nm to 800 nm). Figure 11 The absorption spectra of a toluene solution and a thin film are shown. The horizontal axis represents wavelength (nanometers) and the vertical axis represents absorption intensity (arbitrary units). 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 in the case of the toluene solution, there is an absorption peak at approximately 314 nanometers on the long wavelength side, and in the case of the thin film, there is an absorption peak at approximately 324 nanometers on the long wavelength side.

[0307] The emission spectrum was measured with a fluorescence spectrophotometer (FS920, manufactured by Hamamatsu Photonics Co., Ltd.). Figure 12 The emission spectra of toluene solutions and thin films are shown. The horizontal axis represents wavelength (nanometers), and the vertical axis represents absorption intensity (arbitrary units). The toluene solution was measured in a quartz cell, while the thin film was measured on a sample evaporated onto a quartz substrate. From these spectra, a maximum emission wavelength of 386 nanometers (excitation wavelength: 330 nanometers) can be observed for the toluene solution, and a maximum emission wavelength of 400 nanometers (excitation wavelength: 349 nanometers) can be observed for the thin film.

[0308] Measurement of the film in this atmosphere using a photoelectron spectrophotometer (AC-2, manufactured by Riken Keiki Co., Ltd.) revealed a HOMO energy level of -5.63 eV. The Tauc plot of the film's absorption spectrum showed an absorption edge at 3.34 eV. Therefore, the energy gap in the solid state is approximately 3.34 eV, indicating a LUMO energy level of -2.29 eV. This indicates that BPAFLP (abbreviation) has a relatively deep HOMO energy level and a wide band gap (Bg).

[0309] The characteristics of the oxidation-reduction reaction of BPAFLP (abbreviation) were examined using a cyclic voltammetry (CV) curve. Note that the measurement was performed 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. As a result, 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, it was found that the redox repetition process between the oxidized state and the neutral state has favorable characteristics.

[0311] Note the measurement method described below.

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

[0313] First, the reference electrode (Ag / Ag + The potential energy of the electrode) relative to the vacuum level (eV). In other words, calculate Ag / Ag + The Fermi level of the 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 potential energy of the reference electrode in Example 1 was 0.50 [eV] lower than the potential energy of the standard hydrogen electrode.

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

[0315] (CV test conditions of target substances)

[0316] The solution used for CV measurement used dehydrated dimethylformamide (DMF, Sigma-Aldrich Inc., 99.8%, Catalog No. 22705-6) as a solvent, and tetra-n-butylammonium perchlorate (n-Bu4NClO4, Tokyo Chemical Industry Co., Ltd., Catalog No. T0836) as a supporting electrolyte, dissolved in the solvent to a concentration of 100 mmol / L. Furthermore, the target substance to be measured was dissolved in the solvent to a concentration of 2 mmol / L. A platinum electrode (manufactured by BAS, PTE platinum electrode) was used as a working electrode, a platinum electrode (manufactured by BAS, VC-3 Pt counter electrode, 5 cm) was used as an auxiliary electrode, and an Ag / Ag+ electrode (manufactured by BAS, RE-7 reference electrode, for non-aqueous solvents) was used as a reference electrode. It should be noted that the measurement was performed at room temperature (20° C. to 25° C.) In addition, in all measurements, the scan rate in the CV measurement was set to 0.1 V / sec.

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

[0318] The glass transition temperature was measured using differential scanning calorimetry (Pyris 1DSC, manufactured by Perkin Elmer). The measurement results revealed a glass transition temperature of 107°C. BPAFLP (abbreviation) demonstrated a high glass transition temperature and excellent heat resistance. Furthermore, no crystallization peak was observed; therefore, BPAFLP (abbreviation) was found to be a substance that is difficult to crystallize.

[0319] (Example 2)

[0320] "Synthesis Example 2"

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

[0322] [Chemical Formula 33]

[0323]

[0324] [Step 1: Synthesis of 9-(4′-bromo-4-biphenyl)-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. To this mixture solution, 14 ml (22 mmol) of a hexane solution of n-butyllithium was added dropwise, 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 was acidic, and the mixture was stirred for 4 hours. The solution was washed with water. After washing, magnesium sulfate was added to remove moisture. The suspension was filtered, and the filtrate obtained was concentrated and purified by silica gel column chromatography (eluting solvent, hexane). The concentrated fraction was added with methanol, ultrasonic waves were applied, and recrystallization was performed 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 stirred at 130° C. for 2.5 hours under a nitrogen atmosphere to carry out a reaction.

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

[0329] [Chemical Formula 34]

[0330]

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

[0332] To a 100 ml three-necked flask were added 3.8 g (8.0 mmol) of 9-(4′-bromo-4-biphenyl)-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 di(dibenzylideneacetone)palladium(0), and the atmosphere in the flask was replaced with nitrogen. 20 ml of anhydrous xylene was then added to the mixture. After stirring under reduced pressure while degassing the mixture, 0.2 ml (0.1 mmol) of tri(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 react.

[0333] After the reaction, 200 mL of toluene was added to the reaction mixture solution, and the resulting suspension was filtered through Florisil and Celite. The filtrate was concentrated and purified by silica gel column chromatography (elution solvent, toluene:hexane = 1:4). The resulting fraction was concentrated, and acetone and methanol were added thereto. The mixture was irradiated with ultrasound and then recrystallized to obtain 4.4 g of the target white powder with a yield of 86%. The reaction scheme of the above-mentioned synthesis method is shown below (J-4).

[0334] [Chemical Formula 35]

[0335]

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

[0337] The compound obtained in step 2 was subjected to nuclear magnetic resonance ( 1 The measured data are shown below. Figure 14A and 14B show 1 H-NMR spectrum: The measurement results showed that the fluorene derivative BPAFLBi (abbreviation) of the present invention represented by the structural formula (151) was obtained.

[0338] 1H-NMR (CDCl3, 300MHz): 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 performed 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) (measuring range: 200 nm to 800 nm). Figure 15 The absorption spectra of a toluene solution and a thin film are shown. The horizontal axis represents wavelength (nanometers) and the vertical axis represents absorption intensity (arbitrary units). 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 in the case of the toluene solution, there is an absorption peak at approximately 340 nanometers on the long wavelength side, and in the case of the thin film, there is an absorption peak at approximately 341 nanometers on the long wavelength side.

[0341] The emission spectrum was measured with a fluorescence spectrophotometer (FS920, manufactured by Hamamatsu Photonics Co., Ltd.). Figure 16 The emission spectra of a toluene solution and a thin film are shown. The horizontal axis represents wavelength (nanometers), and the vertical axis represents emission intensity (arbitrary units). The toluene solution was measured in a quartz cell, while the thin film was measured on a sample evaporated onto a quartz substrate. These spectra show a maximum emission wavelength of 386 nanometers (excitation wavelength: 345 nanometers) for the toluene solution and 399 and 419 nanometers (excitation wavelength: 348 nanometers) for the thin film.

[0342] Measurements of the film in this atmosphere using a photoelectron spectrophotometer (AC-2, manufactured by Riken Keiki Co., Ltd.) revealed a HOMO energy level of -5.64 eV. The Tauc plot of the film's absorption spectrum showed an absorption edge at 3.28 eV. Therefore, the energy gap in the solid state is approximately 3.28 eV, indicating a LUMO energy level of -2.36 eV. This indicates that BPAFLBi (abbreviation) has a relatively deep HOMO energy level and a wide band gap (Bg).

[0343] The oxidation-reduction reaction characteristics of BPAFLBi (abbreviation) were detected by cyclic voltammetry (CV) curve. It should be noted that an electrochemical analyzer (ALS model 600A or 600C, manufactured by BAS Inc.) was used for measurement. The measurement method is similar to that in 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. As a result, 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 redox repetition process between the oxidized state and the neutral state has favorable characteristics.

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

[0346] The glass transition temperature was measured using differential scanning calorimetry (Pyris 1DSC, manufactured by Perkin Elmer). The measurement results revealed a glass transition temperature of 126°C. This indicates that BPAFLBi (abbreviation) has a high glass transition temperature and good heat resistance. Furthermore, no crystallization peak was present; therefore, BPAFLBi (abbreviation) was found to be a substance that is difficult to crystallize.

[0347] (Example 3)

[0348] In Example 3, a method for manufacturing 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 the element characteristics are described.

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

[0350] [Chemical Formula 36]

[0351]

[0352] First, indium oxide-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.

[0353] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0354] The substrate provided with the first electrode 1502 is fixed on the substrate holder of the vacuum evaporation equipment so that the surface provided with the first electrode 1502 is downwardly positioned. Reduce the pressure of the vacuum evaporation equipment to about 10 -4 Next, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated: NPB) and molybdenum(VI) oxide were co-evaporated on the first electrode 1502 to form a first layer 1511 (hole injection layer). The thickness was 50 nanometers, and the evaporation rate was controlled to achieve a weight ratio of NPB to molybdenum(VI) oxide of 4:1 (NPB:molybdenum(VI) oxide). It should be noted that co-evaporation is a deposition method in which multiple materials are deposited simultaneously in a single processing chamber using multiple evaporation sources.

[0355] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming a second layer 1512 (hole-transporting layer). Note that Comparative Light-Emitting Element 1 was formed using 4,4'-di[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), and Light-Emitting Element 2 was formed using 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP).

[0356] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by evaporation using resistance heating. Third layer 1513 was formed by co-evaporating 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated: CzPA) and 4-(10-phenyl-9-anthracenyl)-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviated: PCBAPA) to a thickness of 30 nm. The evaporation rate was controlled to achieve a weight ratio of CzPA to PCBAPA of 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 nanometers is formed by an evaporation method using resistance heating, and a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nanometers is formed thereon, thereby forming a fourth layer 1514 (electron transport layer).

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

[0359] Finally, a 200-nanometer-thick aluminum film was formed by an evaporation method using resistance heating to form the second electrode 1504. In this manner, comparative light-emitting element 1 and light-emitting element 2 were formed.

[0360] Note that, except for the second layer 1512, comparative light-emitting element 1 and light-emitting element 2 were formed in the same steps.

[0361] The comparative light-emitting element 1 and light-emitting element 2 thus obtained were sealed in a glove box with 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.).

[0362] Figure 19 The current density and luminance characteristics of Light-emitting Element 1 and Light-emitting Element 2 are compared and shown. Figure 20 The voltage and luminance characteristics of Light-Emitting Element 1 and Light-Emitting Element 2 are shown for comparison. Figure 21 The brightness and current efficiency characteristics of Light-emitting Element 1 and Light-emitting Element 2 are compared. Figure 19 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 20 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 21 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 1 shows that the comparative light-emitting element 1 and the light-emitting element 2 have the same brightness as 1000 cd / m 2 Nearby respective voltage, chromaticity and current efficiency.

[0363] [Table 1]

[0364] Voltage (V) Chroma x Chroma 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 light emitting element 2 is 4.2V, the brightness and current value are 880cd / m 2and 0.41 mA. By comparison with the comparative 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 the carrier balance of the light-emitting element 2 is considered to be improved compared with the light-emitting element 1. Since the HOMO energy level of BPAFLP (abbreviation) is closer to the HOMO energy level of CzPA (abbreviation) (the main material of the light-emitting layer) than the HOMO energy level of NPB, it is considered that the hole injection property from the hole transport layer to the light-emitting layer is improved. In addition, since the LUMO energy level of BPAFLP (abbreviation) is higher than the LUMO energy level of NPB, it is considered that the electron blocking property from the light-emitting layer to the hole transport layer is improved. In addition, since BPAFLP (abbreviation) has a wide band gap (Bg) (compared to NPB), it is considered that the excitons generated in the third layer (light-emitting layer) 1513 are not transferred to the adjacent second layer 1512 (that is, there is no quenching) and are confined.

[0366] (Example 4)

[0367] In Example 4, a method for manufacturing 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 the element characteristics are described.

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

[0369] [Chemical Formula 37]

[0370]

[0371] First, indium oxide-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.

[0372] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0373] The substrate provided with the first electrode 1502 is fixed on the substrate holder of the vacuum evaporation equipment so that the surface provided with the first electrode 1502 is downwardly positioned. Reduce the pressure of the vacuum evaporation equipment to about 10 -4 Next, 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated: CzPA) and molybdenum (VI) oxide were co-evaporated on the first electrode 1502 to form a first layer 1511 (hole injection layer). The thickness was 50 nanometers, and the evaporation rate was controlled to achieve a weight ratio of CzPA to molybdenum (VI) oxide of 4:1 (CzPA:molybdenum (VI) oxide).

[0374] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming the second layer 1512 (hole-transporting layer). Note that the light-emitting element 3 was formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP).

[0375] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by evaporation using resistance heating. Third layer 1513 was formed by co-evaporating 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated: CzPA) and 4-(10-phenyl-9-anthracenyl)-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviated: PCBAPA) to a thickness of 30 nm. The evaporation rate was controlled to achieve a weight ratio of CzPA to PCBAPA of 1:0.10 (CzPA:PCBAPA).

[0376] Thereafter, a fourth electron transport layer, a fifth electron injection layer, and a second electrode were formed in a manner similar to that of the comparative light-emitting element 1. In this way, the light-emitting element 3 was formed.

[0377] The obtained Light-emitting Element 3 was sealed in a glove box of nitrogen atmosphere to prevent contact with air. The operating characteristics of the Light-emitting Element 3 were then measured. Note that the measurement was performed at room temperature (the atmosphere was maintained at 25° C.).

[0378] Figure 22 The current density and luminance characteristics of the light-emitting element 3 are shown. Figure 23 The voltage and brightness characteristics of the light-emitting element 3 are shown. Figure 24 The brightness and current efficiency characteristics of the light emitting element 3 are shown. Figure 22 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 23 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 24The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 2 shows that the light emitting element 3 has a brightness of 1000 cd / m 2 Nearby voltage, chromaticity and current efficiency.

[0379] [Table 2]

[0380] Voltage (V) Chroma x Chroma 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 of the present invention (abbreviation: BPAFLP) possesses the characteristics and full functionality required for a light-emitting element. Furthermore, reliability test results indicate that a highly reliable light-emitting element was obtained, in which short circuits due to film defects, etc., did not occur even when the light-emitting element continuously emitted light.

[0382] Figure 25 The continuous lighting test results of the light emitting element 3 under constant current driving are shown. The initial brightness is set to 1000 cd / m 2 (Assuming 1000cd / m 2 The vertical axis represents relative brightness. Figure 25 As can be seen from the results, Light-emitting Element 3 exhibited 78% of the initial luminance even after 1000 hours, indicating that Light-emitting Element 3 had a long life. Therefore, it was found that a long-life light-emitting element can be obtained 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-phenylfluorene-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi) synthesized in Example 1 and Example 2, a light-emitting element formed using 4-phenyl-4′-(9-phenylfluorene-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 follows Figure 18 The fluorene derivative of the present invention is used in the hole injection layer and the hole transport layer to form a light-emitting element. The structural formula of the organic compound in Example 5 is shown below.

[0386] [Chemical Formula 38]

[0387]

[0388] First, indium oxide-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.

[0389] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0390] The substrate provided with the first electrode 1502 was fixed to the substrate holder of a vacuum evaporation apparatus, with the surface provided with the first electrode 1502 facing downward. The pressure of the vacuum evaporation apparatus was reduced to approximately 10-4 Pa. Next, a fluorene derivative according to an embodiment of the present invention and molybdenum (VI) oxide were co-evaporated on the first electrode 1502 to form a first layer 1511 (hole injection layer). The thickness was 50 nanometers, and the evaporation rate was controlled to achieve a weight ratio of fluorene derivative to molybdenum (VI) oxide of 4:1 (fluorene derivative:molybdenum oxide). Note that Light-Emitting Element 4 was formed using 4-phenyl-4′-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviated: BPAFLBi) as the fluorene derivative, and Light-Emitting Element 5 was formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviated: BPAFLP) as the fluorene derivative.

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

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

[0393] Next, a second emitting layer was formed on the first emitting layer by evaporation using resistance heating. The second emitting layer was formed by co-evaporating 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated: CzPA) and 4-(10-phenyl-9-anthracenyl)-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviated: PCBAPA) onto the first emitting layer to a thickness of 15 nanometers. The evaporation rate was controlled to maintain a weight ratio of CzPA to PCBAPA of 1:0.05 (CzPA:PCBAPA).

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

[0395] Note that, except for the first layer 1511 and the second layer 1512, the light-emitting element 4 and the light-emitting element 5 are formed in the same steps.

[0396] The light-emitting element 4 and the light-emitting element 5 thus obtained were sealed in a glove box with 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.).

[0397] Figure 26 The current density and luminance characteristics of Light-Emitting Element 4 and Light-Emitting Element 5 are shown. Figure 27 The voltage and luminance characteristics of Light-Emitting Element 4 and Light-Emitting Element 5 are shown. Figure 28 The luminance and current efficiency characteristics of light-emitting element 4 and light-emitting element 5 are shown. Figure 26 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 27 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 28 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 3 shows that the light emitting element 4 and the light emitting element 5 have a light intensity of 1000 cd / m 2 Nearby respective voltage, chromaticity, current efficiency and external quantum efficiency.

[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 full functions of light-emitting elements. In addition, the reliability test results show that highly reliable light-emitting elements are obtained, in which short circuits caused by film defects, etc., are not caused even when the light-emitting element continuously emits light.

[0401] Figure 29 The continuous lighting test results of light emitting element 4 and light emitting element 5 are shown in Figure 1. The initial brightness is set to 1000 cd / m 2 (Assuming 1000cd / m 2 The vertical axis represents relative brightness. Figure 29 As can be seen from the results, Light-emitting Element 4 still exhibited 74% of the initial luminance even after 850 hours, and Light-emitting Element 5 still exhibited 75% of the initial luminance even after 850 hours, indicating that Light-emitting Element 4 and Light-emitting Element 5 have long lifetimes. Therefore, it was found that long-life light-emitting elements can be obtained using BPAFLBi (abbreviation) and BPAFLP (abbreviation) of the present invention.

[0402] (Example 6)

[0403] In Example 6, a method for manufacturing 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 the element characteristics are described.

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

[0405] [Chemical Formula 39]

[0406]

[0407] First, indium oxide-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.

[0408] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0409] The substrate with the first electrode 1502 is secured to the substrate holder of a vacuum evaporation apparatus, with the surface with the first electrode 1502 facing downward. The pressure of the vacuum evaporation apparatus is reduced to approximately 10-4 Pa. Next, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated: NPB) and molybdenum (VI) oxide are co-evaporated onto the first electrode 1502 to form a first layer 1511 (hole injection layer). The thickness is 50 nanometers, and the evaporation rate is controlled to achieve a weight ratio of NPB to molybdenum (VI) oxide of 4:2 (NPB:molybdenum oxide). It should be noted that co-evaporation is a deposition method in which multiple materials are deposited simultaneously in a single processing chamber using multiple evaporation sources.

[0410] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming a second layer 1512 (hole-transporting layer). Note that Light-Emitting Element 6 was formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and Light-Emitting Element 7 was formed using 4,4′-di[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB).

[0411] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by an evaporation method using resistance heating. 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II) and acetylacetonate (2-phenylpyridinium chloride-N,C 2′ ) iridium (III) (abbreviation: Ir(ppy)2acac) is formed into a 40 nm thick film as the third layer 1513. Here, the evaporation rate is controlled 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, a film of bis(2-methyl-8-hydroxyquinoline)(4-phenylphenolate)aluminum(III) (abbreviation: BAlq) with a thickness of 10 nanometers is formed by an evaporation method using resistance heating, and a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nanometers is formed thereon, thereby forming a fourth layer 1514 (electron transport layer).

[0413] Thereafter, a fourth electron transport layer, a fifth electron injection layer, and a second electrode were formed in a manner similar to that of the comparative light-emitting element 1. In this way, comparative light-emitting elements 6 and 7 were formed.

[0414] Note that, except for the second layer 1512, the light-emitting element 6 and the comparative light-emitting element 7 were formed in the same steps.

[0415] The light-emitting element 6 and the comparative light-emitting element 7 thus obtained were sealed in a glove box with 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.).

[0416] Figure 30 The current density and luminance characteristics of Light-emitting Element 6 and Comparative Light-emitting Element 7 are shown. Figure 31 The voltage and luminance characteristics of the light-emitting element 6 and the comparative light-emitting element 7 are shown. Figure 32 The luminance and current efficiency characteristics of the light-emitting element 6 and the comparative light-emitting element 7 are shown. Figure 30 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 31 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 32 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 4 shows that the light-emitting element 6 and the comparative light-emitting element 7 have the same brightness at 1000 cd / m 2 Nearby respective voltage, chromaticity, current efficiency and external quantum efficiency.

[0417] [Table 4]

[0418]

[0419] Figure 33 Emission spectra of Light-emitting Element 6 and Comparative Light-emitting Element 7 are shown.

[0420] like Figure 33 As 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 is observed. This shows that the ability of NPB to block electrons is low, and even in the NPB with internal quantum efficiency, some recombination occurs. As a result, it is believed that the current efficiency and external quantum efficiency are reduced. In addition, it is believed that since NPB has low triplet excitation energy, the triplet excitation energy is easily transferred from the light-emitting layer to NPB, which leads to a decrease in current efficiency and external quantum efficiency. On the other hand, in the light-emitting element 6, only emission from the dopant in the light-emitting layer is observed, and emission from BPAFLP (abbreviation) in the hole transport layer is not observed. Accordingly, it is shown that BPAFLP has high electron blocking ability and also has large triplet excitation energy. As a result, the excitation energy generated is mainly consumed by the dopant (phosphorescent material in the light-emitting layer) to form light, so that high current efficiency can be obtained. Therefore, it is confirmed that the 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, a method for manufacturing 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 the element characteristics are described.

[0423] The element structures of the light-emitting elements 8 to 10 in Example 7 are as follows: Figure 18 As shown. Light-emitting element 9 uses the above-mentioned fluorene derivative of the present invention for the transport layer, and light-emitting element 10 uses the above-mentioned fluorene derivative of the present invention for the hole injection layer and the hole transport layer. The structural formula of the organic compound in Example 7 is shown below.

[0424] [Chemical Formula 40]

[0425]

[0426] First, indium oxide-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.

[0427] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0428] The substrate provided with the first electrode 1502 is fixed on the substrate holder of the vacuum evaporation equipment so that the surface provided with the first electrode 1502 is downwardly positioned. Reduce the pressure of the vacuum evaporation equipment to about 10 -4 Pa. Then, a hole injection material was deposited on first electrode 1502 to a thickness of 50 nanometers to form first layer 1511 (hole injection layer). Note that when forming Light-Emitting Element 8 and Light-Emitting Element 9, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated: NPB) and molybdenum(VI) oxide were co-evaporated to form first layer 1511 (hole injection layer 1511). The thickness was 50 nanometers, and the evaporation rate was controlled so that the weight ratio of NPB to molybdenum(VI) oxide was 4:2 (NPB:molybdenum oxide). Furthermore, when forming Light-Emitting Element 10, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated: BPAFLP) and molybdenum(VI) oxide were co-evaporated to form first layer 1511 (hole injection layer). The thickness was 50 nanometers, and the evaporation rate was controlled so that the weight ratio of BPAFLP to molybdenum(VI) oxide was 4:2 (BPAFLP:molybdenum oxide).

[0429] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming a second layer 1512 (hole-transporting layer). Note that Light-Emitting Element 8 was formed using 4-phenyl-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviation: PCBA1BP), while Light-Emitting Element 9 and Light-Emitting Element 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 evaporation using resistance heating. 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviated: CO11II), 4-phenyl-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviated: PCBA1BP), and iridium(III) bis{2-(4-fluorophenyl)-3,5-dimethylpyridine}(picolinate) (abbreviated: Ir(dmFppr)2pic) were co-evaporated to form a 40-nanometer-thick film as third layer 1513. The evaporation rate was controlled to maintain a weight ratio of CO11II to PCBA1BP to Ir(dmFppr)2pic of 1:0.15:0.1 (CO11II:PCBA1BP:Ir(dmFppr)2pic).

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

[0432] Note that, except for the first layer 1511 and the second layer 1512 , the light-emitting elements 8 to 10 are formed in the same steps.

[0433] The light-emitting elements 8 to 10 thus obtained were sealed in a glove box of 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 The current density and luminance characteristics of light-emitting elements 8 to 10 are shown. Figure 35 The voltage and brightness characteristics of light-emitting elements 8 to 10 are shown. Figure 36 The luminance and current density characteristics of light-emitting elements 8 to 10 are shown. Figure 34 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 35In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 36 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 5 shows that the light emitting element 8 to the light emitting element 10 have a brightness of 1000 cd / m 2 Nearby respective voltage, chromaticity, current efficiency and external quantum efficiency.

[0435] [Table 5]

[0436]

[0437] Light-emitting elements 8 to 10 each achieved high luminescence efficiency; however, light-emitting element 9, which used BPAFLP for the hole transport layer, was found to have higher current efficiency than light-emitting element 8. Furthermore, light-emitting element 10, which used BPAFLP for both the hole injection layer and the hole transport layer, was found to have higher current efficiency than light-emitting element 9.

[0438] Figure 37 The continuous lighting test results of light-emitting elements 8 to 10 are shown, with the initial brightness set to 1000 cd / m 2 (Assuming 1000cd / m 2 The vertical axis represents relative brightness. Figure 37 The results show that Light-emitting Element 8 still exhibited 64% of its initial brightness even after 650 hours. Light-emitting Element 9 still exhibited 71% of its initial brightness after 500 hours, and Light-emitting Element 10 still exhibited 72% of its initial brightness after 500 hours. Thus, it was found that using BPAFLP (abbreviation) according to an embodiment of the present invention can produce a long-life light-emitting element.

[0439] (Example 8)

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

[0441] The structural formulas used in the simulation are shown below.

[0442] [Chemical Formula 41]

[0443]

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

[0445] Next, using the most stable structures in the singlet and triplet states obtained in the above calculations, the excitation energies of structure (101) (abbreviated: BPAFLP), structure (109), structure (114), structure (151) (abbreviated: BPAFLBi), structure (164), and NPB were calculated using time-dependent density functional theory. The basis functions and functionals used in these calculations are the same as those described 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 through the above calculation.

[0447] [Table 6]

[0448]

[0449] The results in Table 6 show that the HOMO energy levels of the above fluorene derivatives are lower than that of NPB. Therefore, it is demonstrated that when any of the above fluorene derivatives is used as a hole transport material, it has a better property of injecting holes into the light-emitting layer having a deeper HOMO energy level than NPB.

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

[0451] [Table 7]

[0452]

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

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

[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, 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 compared to NPB. In addition, it was found that when any of the fluorene derivatives is used as a phosphorescent host material, it can easily excite the guest material.

[0459] (Example 9)

[0460] In Example 9, a method for manufacturing 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 the element characteristics are described.

[0461] The element structures of the light-emitting element 11 in Example 9 and the comparative light-emitting element 12 are as follows: Figure 18 The light-emitting element 11 is formed by using the fluorene derivative of the present invention as the hole injection layer and the hole transport layer.

[0462] First, indium oxide-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.

[0463] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0464] The substrate provided with the first electrode 1502 is fixed on the substrate holder of the vacuum evaporation equipment so that the surface provided with the first electrode 1502 is downwardly positioned. Reduce the pressure of the vacuum evaporation equipment to about 10 -4Pa. Then, a hole injection material was deposited on the first electrode 1502 to a thickness of 50 nanometers to form a 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 were co-evaporated to form the first layer 1511 (hole injection layer 1511). The thickness was 50 nanometers, and the evaporation rate was controlled so that the weight ratio of BPAFLP to molybdenum (VI) oxide was 4:2 = (BPAFLP: molybdenum oxide). In addition, when forming the comparative light-emitting element 12, 4,4′,4″-tris(carbazolyl-9-yl)triphenylamine (abbreviation: TCTA) and molybdenum (VI) oxide were co-evaporated to form the first layer 1511 (hole injection layer). The thickness was 50 nanometers, and the evaporation rate was controlled so that the weight ratio of TCTA to molybdenum (VI) oxide was 4:2 = (TCTA: molybdenum oxide).

[0465] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming a second layer 1512 (hole-transporting layer). Note that the light-emitting element 11 was formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), while the comparative light-emitting element 12 was formed using 4,4′,4″-tris(carbazolyl-9-yl)triphenylamine (abbreviation: TCTA).

[0466] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by an evaporation method using resistance heating. 9-[4-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)phenyl]-9H-carbazole (abbreviation: CzTAZ1) and bis[2-(4′,6′-difluorophenyl)pyridinyl]-N,C-pyridinyl]-1,2,4-triazol-3- ... 2′ Iridium (III) (abbreviation: FIrpic) was formed into a 30 nm thick film as the third layer. The evaporation rate was controlled so that the weight ratio of CzTAZ1 to FIrpic was 1:0.06 (CzTAZ1:FIrpic).

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

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

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

[0470] The light-emitting element 11 and the comparative light-emitting element 12 thus obtained were sealed in a glove box with 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.).

[0471] Figure 38 The current density and luminance characteristics of the light-emitting element 11 and the comparative light-emitting element 12 are shown. Figure 39 The voltage and luminance characteristics of the light-emitting element 11 and the comparative light-emitting element 12 are shown. Figure 40 The luminance and current efficiency characteristics of the light-emitting element 11 and the comparative light-emitting element 12 are shown. Figure 38 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 39 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 40 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 9 shows that the light-emitting element 11 and the comparative light-emitting element 12 have a brightness of 1000 cd / m 2 Nearby respective voltage, chromaticity, current efficiency and external quantum efficiency.

[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 , the current value is 0.18mA. When the driving voltage of the comparative light-emitting element 12 using TCTA (abbreviation) instead of BPAFLP (abbreviation) is 5.2V, the brightness is 850cd / m2 and the current value is 0.19mA. 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 than the comparative light-emitting element 12. It was found that the application of BPAFLP (abbreviation) of the embodiment of the present invention to the hole injection layer and the hole transport layer can obtain a high-efficiency light-emitting element.

[0476] Figure 41Emission spectra of Light-emitting Element 11 and Comparative Light-emitting Element 12 are shown.

[0477] In both Light-Emitting Element 11 and Comparative Light-Emitting Element 12, emission spectra from the phosphorescent dopant material FIrpic (abbreviated) were observed, while no light emission from adjacent layers of the third layer 1513 was observed. This indicates that in both elements, carriers preferentially recombine in the third layer 1513, resulting in light emission from a well-balanced carrier balance. This suggests that because Light-Emitting Element 11 exhibits higher current efficiency than Comparative Light-Emitting Element 12, BPAFLP (abbreviated) exhibits better carrier balance (blocking electrons from the third layer 1513 and receiving more holes flowing into the third layer 1513) and also has higher triplet excitation energy. At this point, the LUMO energy level of BPAFLP (abbreviated) according to the present embodiment is almost identical to that of TCTA (abbreviated) (-2.30 eV), and the band gap (Bg) of BPAFLP (abbreviated) is narrower than that of TCTA (abbreviated) (3.40 eV); therefore, BPAFLP (abbreviated) according to the present embodiment is a material with superior hole-transport properties. Therefore, it is considered that carrier recombination can be efficiently performed in the light-emitting layer, thereby achieving higher efficiency.

[0478] (Example 10)

[0479] In Example 10, a method for manufacturing 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 the element characteristics are described.

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

[0481] First, indium oxide-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] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0483] The substrate provided with the first electrode 1502 is fixed on the substrate holder of the vacuum evaporation equipment so that the surface provided with the first electrode 1502 is downwardly positioned. Reduce the pressure of the vacuum evaporation equipment to about 10 -4 Pa. Then, a hole injection material was deposited on the first electrode 1502 to a thickness of 50 nanometers to form a first layer 1511 (hole injection layer). When forming the light-emitting element 13, 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviated: BPAFLP) and molybdenum (VI) oxide were co-evaporated to form the first layer 1511 (hole injection layer 1511). The thickness was 50 nanometers, and the evaporation rate was controlled to achieve a weight ratio of BPAFLP to molybdenum (VI) oxide of 4:2 (BPAFLP:molybdenum oxide).

[0484] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming the second layer 1512 (hole-transporting layer). Note that the light-emitting element 13 was formed using 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP).

[0485] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by evaporation using resistance heating. 4-[3-(Benzo[9,10]phenanthrene-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II) and tris(2-phenylpyridinium-N,C 2′ ) iridium (III) (abbreviation: Ir(ppy) 3 ) to form the third layer 1513. Here, the evaporation rate is controlled 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, a 10-nm thick mDBTPTp-II film is formed by evaporation using resistance heating, and a 20-nm thick bathophenanthroline (abbreviation: BPhen) film is formed thereon to form the fourth layer 1514 (electron transport layer).

[0487] Thereafter, a fifth electron injection layer and a second electrode were formed in a manner similar to that of the comparative light-emitting element 1. In this way, the light-emitting element 13 was formed.

[0488] The obtained Light-Emitting Element 13 was sealed in a glove box of nitrogen atmosphere to prevent contact with air. The operating characteristics of the Light-Emitting Element 13 were then measured. Note that the measurement was performed at room temperature (the atmosphere was maintained at 25° C.).

[0489] Figure 42 The current density and brightness characteristics of the light-emitting element 13 are shown. Figure 43 The voltage and brightness characteristics of the light-emitting element 13 are shown. Figure 44 The brightness and current efficiency characteristics of the light emitting element 13 are shown. Figure 42 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 43 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 44 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 10 shows that the light emitting element 13 has a brightness of 1000 cd / m 2 Nearby voltage, chromaticity, current efficiency and external quantum efficiency.

[0490] [Table 10]

[0491]

[0492] According to Example 10, a light-emitting element using the fluorene derivative of the present invention (abbreviation: BPAFLP) was confirmed to have characteristics sufficient for use as a light-emitting element. Furthermore, reliability test results indicate that a highly reliable light-emitting element was obtained, in which short circuits due to film defects, etc., did not occur even when the light-emitting element continuously emitted light.

[0493] In addition, the light emitting element 13 was driven by a constant current to continuously emit light for a continuous lighting test, and the initial brightness was set to 1000 cd / m 2 Even after 1900 hours, 86% of the initial luminance was retained. Thus, it was found that Light-Emitting Element 13 had a long lifetime. Therefore, it was confirmed that applying BPAFLP (abbreviation) according to an embodiment of the present invention to a hole injection layer can provide a light-emitting element with a long lifetime.

[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 in an embodiment of the present invention is described. Specifically, a method for synthesizing 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 of 9-(3-bromophenyl)-9-phenylfluorene]

[0500] To a 200 ml three-necked flask was added 30 ml of a solution of 4.2 g (18 mmol) of 2-bromobiphenyl in anhydrous THF, and the mixture was stirred at -78°C. To this mixture was added dropwise 11 ml (18 mmol) of a 1.57 M solution of n-BuLi in hexane, and the mixture was stirred for 2.5 hours. Then, to this mixture was added dropwise 40 ml of a solution of 3.9 g (15 mmol) of 3-bromobenzophenone in anhydrous THF, and the mixture was stirred for 2 hours and then at room temperature for 16 hours.

[0501] After the reaction, 1N dilute hydrochloric acid was added to the mixture solution, and the mixture was stirred for 1 hour. The mixture was washed with water. The obtained organic phase was concentrated to obtain a candy-like substance.

[0502] Next, the candy-like substance, 20 ml of glacial acetic acid and 1.0 ml of hydrochloric acid were added to a 200 ml recovery flask, and the mixture was stirred at 130° C. for 2 hours under a nitrogen atmosphere to carry out a reaction.

[0503] After the reaction, the reaction mixture solution was added dropwise to 150 ml of ice water to precipitate a caramel-like solid. The insoluble components were removed by decantation. The caramel-like solid was dissolved in 100 ml of toluene, a saturated aqueous solution of sodium bicarbonate was added thereto, and the toluene solution was stirred until no more bubbles were generated. The organic layer was washed with water, and silica gel was added to absorb moisture. The filtrate obtained by filtering the mixture was concentrated, and methanol was added thereto. The mixture was assisted by ultrasound and cooled with ice, and the solid produced was filtered. 4.9 g of target white powder was obtained with a yield of 83%. The reaction scheme of the above-mentioned synthetic method is shown below (J-5).

[0504] [Chemical Formula 43]

[0505]

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

[0507] To a 200 ml three-necked flask were added 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), and the atmosphere in the flask was replaced with nitrogen. 25 ml of anhydrous xylene was then added to the mixture. After degassing the mixture while stirring under reduced pressure, 0.2 ml (0.1 mmol) of tri(tert-butyl)phosphine (10 wt% hexane solution) was added to the mixture. The mixture was heated and stirred at 130° C. in a nitrogen atmosphere for 2.5 hours to allow the reaction to proceed.

[0508] 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 Pure Chemical Industries, catalog number 540-00135), alumina, and Celite (produced by Wacker Pure Chemical Industries, catalog number 531-16855). The obtained filtrate was concentrated and purified by silica gel column chromatography (developing solvent, toluene:hexane = 1:4). The resulting fraction was concentrated, and acetone and methanol were added thereto. The mixture was irradiated with ultrasound and then recrystallized to obtain 3.2 g of the target white powder with a yield of 97%. The reaction scheme of the above-mentioned synthesis method is shown below (J-6).

[0509] [Chemical Formula 44]

[0510]

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

[0512] The compound obtained in step 2 was subjected to nuclear magnetic resonance ( 1 The measured data are shown below. Figure 45A and 45B show 1 H-NMR spectrum: The measurement results showed that the fluorene derivative mBPAFLP (abbreviation) of the present invention represented by the structural formula (118) was obtained.

[0513] 1 H-NMR (CDCl3, 300MHz): 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, a main peak with a molecular weight of 561.3 (mode: EI+) was measured, confirming that the target mBPAFLP (abbreviation) was obtained.

[0515] The following tests were performed 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) (measuring range: 200 nm to 800 nm). Figure 46 The absorption spectra of toluene solution and film are shown. The horizontal axis represents wavelength (nanometers) and the vertical axis represents absorption intensity (arbitrary units). The toluene solution is placed in a quartz cell for measurement. The displayed spectrum is obtained by subtracting the absorption spectra of quartz and toluene from the absorption spectrum of the sample. The sample obtained by evaporating the film on a quartz substrate is measured, and the displayed spectrum is 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 case of the toluene solution, there are absorption peaks at approximately 310 nanometers and 325 nanometers on the long wavelength side, and for the case of the film, there are absorption peaks at approximately 312 nanometers and 329 nanometers on the long wavelength side.

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

[0518] Measurement of the film in this atmosphere using a photoelectron spectrophotometer (AC-2, manufactured by Riken Keiki Co., Ltd.) revealed a HOMO energy level of -5.73 eV. The Tauc plot of the film's absorption spectrum showed an absorption edge at 3.34 eV. Therefore, the energy gap in the solid state is approximately 3.34 eV, indicating a LUMO energy level of -2.39 eV. This indicates that mBPAFLP (abbreviation) has a relatively deep HOMO energy level and a wide band gap (Bg).

[0519] The characteristics of the oxidation-reduction reaction of mBPAFLP (abbreviation) were examined using a cyclic voltammetry (CV) curve. Note that the measurement was performed 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. As a result, the HOMO energy level was found to be -5.53 [eV]. In addition, the oxidation peak remained at a similar value even after 100 cycles. Accordingly, it was found that the redox repetition process between the oxidized state and the neutral state has favorable characteristics.

[0521] The melting point was measured and found to be 211°C-212°C.

[0522] (Example 12)

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

[0524] The element structure of the light emitting element in Example 12 is as follows Figure 18 The light-emitting element 14 was formed using the fluorene derivative (abbreviation: mBPAFLP) of the present invention for the hole injection layer and the hole transport layer.

[0525] First, indium oxide-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.

[0526] Next, an EL layer 1503 including a plurality of stacked layers is formed over 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 this order.

[0527] The substrate provided with the first electrode 1502 is fixed on the substrate holder of the vacuum evaporation equipment so that the surface provided with the first electrode 1502 is downwardly positioned. Reduce the pressure of the vacuum evaporation equipment to about 10 -4Pa. Then, a hole injection material was deposited on first electrode 1502 to a thickness of 50 nanometers to form first layer 1511 (hole injection layer). In forming light-emitting element 14, 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (mBPAFLP) and molybdenum (VI) oxide were co-evaporated to form first layer 1511 (hole injection layer 1511). The thickness was 50 nanometers, and the evaporation rate was controlled so that the weight ratio of mBPAFLP to molybdenum (VI) oxide was 4:2 (mBPAFLP:molybdenum oxide). Note that in forming comparative light-emitting element 15, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) and molybdenum (VI) oxide were co-evaporated to form first layer 1511 (hole injection layer 1511). The thickness was 50 nanometers, and the evaporation rate was controlled so that the weight ratio of NPB to molybdenum (VI) oxide was 4:2 (NPB:molybdenum oxide).

[0528] Next, a hole-transporting material was deposited on the first layer 1511 by evaporation using resistance heating to a thickness of 10 nm, forming a second layer 1512 (hole-transporting layer). Note that the light-emitting element 14 was formed using 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), while the comparative light-emitting element 15 was formed using 4,4′-di[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB).

[0529] Next, a third layer 1513 (light-emitting layer) was formed on the second layer 1512 by evaporation using resistance heating. A 30-nanometer-thick film was formed by co-evaporating 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated: CzPA) and 4-(10-phenyl-9-anthracenyl)-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviated: PCBAPA). The evaporation rate was controlled to maintain a weight ratio of CzPA to PCBAPA of 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 nanometers is formed by an evaporation method using resistance heating, and a film of bathophenanthroline (abbreviation: BPhen) with a thickness of 20 nanometers is formed thereon, thereby forming a fourth layer 1514 (electron transport layer).

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

[0532] Finally, a 200-nanometer-thick aluminum film was formed by an evaporation method using resistance heating, thereby forming the second electrode 1504. In this manner, the light-emitting element 14 and the comparative light-emitting element 15 were formed.

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

[0534] The light-emitting element 14 and the comparative light-emitting element 15 thus obtained were sealed in a glove box with 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.).

[0535] Figure 48 The current density and luminance characteristics of the light-emitting element 14 and the comparative light-emitting element 15 are shown. Figure 49 The voltage and luminance characteristics of the light-emitting element 14 and the comparative light-emitting element 15 are shown. Figure 50 The luminance and current efficiency characteristics of the light-emitting element 14 and the comparative light-emitting element 15 are shown. Figure 48 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents the current density (mA / cm 2 ).exist Figure 49 In the figure, the vertical axis represents the brightness (cd / m 2 ), the horizontal axis represents voltage (V). Figure 50 The vertical axis represents the current efficiency (cd / A) and the horizontal axis represents the brightness (cd / m 2 ). In addition, Table 11 shows that the light-emitting element 14 and the comparative light-emitting element 15 have a brightness of 1000 cd / m 2 Nearby respective voltage, chromaticity and current efficiency.

[0536] [Table 11]

[0537]

[0538] When the driving voltage of the light emitting element 14 is 3.4V, the brightness is 1100cd / m 2and a current value of 0.72 mA. It was found that the current efficiency of the light-emitting element 14 using mBPAFLP (abbreviation) for the second layer 1512 was higher than that of the comparative light-emitting element 15 using NPB for the second layer 1512. It is understood that this is because the carrier balance of the light-emitting element 14 is improved compared to the comparative light-emitting element 15. It is believed 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 to NPB), the hole injection properties of mBPAFLP from the hole transport layer to the light-emitting layer are improved. In addition, it is believed that since mBPAFLP (abbreviation) has a high LUMO energy level (compared to NPB), the electron blocking properties of mBPAFLP (abbreviation) from the light-emitting layer to the hole transport layer are improved. In addition, since mBPAFLP (abbreviation) has a wide band gap (Bg) (compared to NPB), it is believed that the excitons generated in the third layer (light-emitting layer) 1513 are not transferred to the adjacent second layer 1512 (that is, there is no quenching) and are confined.

[0539] Furthermore, when the light emitting element 14 and the comparative light emitting element 15 were driven by a constant current and continuously emitted light, the initial brightness was set to 1000 cd / m 2 (Assuming 1000cd / m 2 (The vertical axis represents relative brightness, with the vertical axis representing 100% as 100%). After 280 hours, Light-emitting Element 14 exhibited 80% of the initial brightness, while Comparative Light-emitting Element 15 exhibited 72% of the initial brightness. Therefore, Light-emitting Element 14 and Comparative Light-emitting Element 15 have long lifetimes. Thus, it was found that long-lifetime light-emitting elements can be obtained using the mBPAFLP (abbreviation) of the present invention.

[0540] (Comparative Example 1)

[0541] The synthesis method of 4-(10-phenyl-9-anthracenyl)-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-anthracenyl)-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 were added 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, and the atmosphere in the flask was replaced with nitrogen. Then, 60 ml of toluene and 0.30 ml of tri(tert-butyl)phosphine (10 wt% hexane solution) were added to the mixture. After stirring under reduced pressure while degassing the mixture, 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, approximately 50 ml of toluene was added to the mixture. The mixture was filtered through Celite (Wacker Pure Chemical Industries, catalog number 531-16855), aluminum oxide, and Florisil (Wacker Pure Chemical Industries, catalog number 540-00135). The resulting filtrate was concentrated to obtain a yellow solid. This solid was recrystallized from toluene / hexane to obtain 6.6 g of PCBAPA as a light yellow powdery solid, the target product, with a yield of 75%.

[0548] 3.0 g of the resulting light yellow powdered solid was then sublimated and purified using a multi-stage sublimation method. PCBAPA was heated at 350°C under a pressure of 8.7 Pa and an argon flow rate of 3.0 mL / min. After sublimation purification, 2.7 g of light yellow PCBAPA solid was obtained, with a yield of 90%.

[0549] The obtained compound was subjected to nuclear magnetic resonance (NMR) measurement. The measurement data are shown below.

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

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

[0552] Light-emitting element 1 to light-emitting element 5 described in the above embodiments can be formed using 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazolyl-3-yl)triphenylamine (abbreviation: PCBAPA).

[0553] (Comparative Example 2)

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

[0555] [Chemical Formula 47]

[0556]

[0557] (Y-1) shows a 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] 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 were added to a 100 ml three-necked flask, and the atmosphere in the flask was replaced with nitrogen. 30 ml of toluene and 0.2 ml of a 10 wt% hexane solution of tri(tert-butyl)phosphine were added to the mixture, the pressure of the flask was reduced with an aspirator to deaerate the mixture, and then the atmosphere in the flask was replaced with nitrogen. 0.058 g (0.10 mmol) of bis(dibenzylideneacetone)palladium(0) was added to the mixture, followed by stirring at 80°C in a nitrogen stream for 15 hours. After stirring, toluene was added to the mixture, and the suspension was washed successively with a saturated aqueous solution of sodium carbonate and saturated brine. Magnesium sulfate was then added to the organic layer to remove moisture. The mixture was then suction filtered to obtain a filtrate. The obtained filtrate was filtered with suction through Celite (manufactured by Wacker Pure Chemical Industries, Ltd., catalog number 531-16855) to obtain a filtrate. The compound obtained by concentrating the obtained filtrate was purified by silica gel column chromatography. Column chromatography was performed using toluene as the eluting solvent, and then using a mixed solvent of toluene:ethyl acetate = 4:1 as the eluting solvent. Acetone was added to the solid obtained by concentrating the fraction, and the solid was washed by ultrasonic irradiation. The compound was filtered to collect the solid. The collected solid was recrystallized from a mixed solvent of chloroform and hexane to obtain 2.0 g of a powdery white solid with a yield of 64%.

[0561] 1.1 g of the resulting pale yellow powdered solid was sublimed and purified by a multi-stage sublimation process. Sublimation purification was performed at 240°C for 16 hours under a reduced pressure of 3.0 Pa and an argon flow rate of 5 ml / min. This yielded 0.98 g of a white solid, with a yield of 89%.

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

[0563] 1 H-NMR (CDCl3, 300MHz): δ (ppm) = 7.30-7.76 (m, 13H), 7.79 (d, J = 8.3Hz, 2H), 8.14-8.24 (m, 3H), 8.35 (sd, J = 1.5Hz, 1H), and 8.39 (d, J = 8.8Hz, 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] Light-emitting element 6 to light-emitting element 10 described in the above embodiments can be formed using 3-phenyl-9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11II).

[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 is 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 placed, and the air in the flask was replaced with nitrogen. Then, 50 ml of toluene and 0.30 ml of tri(tert-butyl)phosphine (10 wt% hexane solution) were added to the mixture.

[0574] After degassing the mixture while stirring under reduced pressure, 0.10 g of di(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 Pure Chemical Industries, Ltd., catalog number 531-16855), aluminum oxide and Florisil (produced by Wacker Pure Chemical Industries, Ltd., catalog number 540-00135) to obtain a filtrate. The obtained filtrate was washed with a saturated aqueous solution of sodium carbonate and saturated brine in sequence. Then, magnesium sulfate was added to the organic layer to remove moisture. After drying, the mixture was filtered to remove magnesium sulfate to obtain a filtrate.

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

[0576] 1.2 g of the resulting white powdery solid was sublimed and purified by a multi-stage sublimation process. Sublimation purification was performed at 280°C for 20 hours under a reduced pressure of 7.0 Pa and an argon flow rate of 3 ml / min. This yielded 1.1 g of a white solid, with a yield of 89%.

[0577] The obtained compound was subjected to nuclear magnetic resonance (NMR) measurement. The measurement data are shown below.

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

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

[0580] Light-emitting elements 8 to 10 can be formed using 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP).

[0581] (Comparative Example 4)

[0582] Another method for synthesizing 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) used in Comparative Example 3 is described in detail. This method is preferred because it can easily obtain the target substance with high purity in high yield.

[0583] [Chemical Formula 51]

[0584]

[0585] [Step 1: Synthesis of 3-(4-bromophenyl)-9-phenyl-9H-carbazole]

[0586] (Z-2) shows a synthesis scheme of 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 tri(o-tolyl)phosphine, 50 ml of toluene, 10 ml of ethanol and 25 ml of an aqueous potassium carbonate solution (2 mol / L) was stirred and degassed under reduced pressure, and heated and stirred at 80°C under a nitrogen atmosphere for 6 hours to carry out a 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 Pure Chemical Industries, Ltd., catalog number 540-00135) and Celite (produced by Wacker Pure Chemical Industries, Ltd., catalog number 531-16855). The resulting 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 resulting fraction was concentrated and hexane was added thereto. The mixture was irradiated with ultrasound 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 was 0.32, and the Rf value of 4-bromoiodobenzene was 0.74, which were determined by silica gel column thin layer chromatography (TLC) (elution solvent, ethyl acetate:hexane=1:10).

[0592] The by-product 1,4-di(9-phenyl-9H-carbazolyl-3-yl)benzene had an RF value of 0.23 (elution solvent, ethyl acetate:hexane=1:10); however, spots were slightly observed in the reaction suspension on TLC.

[0593] As a result, it can be understood that because the iodine portion of 4-bromoiodobenzene (a dihalide and used as a source material) has higher reactivity than the bromine portion, it selectively (preferably) reacts with the boron compound 9-phenyl-9H-carbazolyl-3-boronic acid (i.e., the dihalide and the boron compound react in an almost 1:1 ratio). In addition, since the RF value of the target substance and the RF value of the by-product are sufficiently different, the target product and the by-product can be easily separated in the above-mentioned chromatography.

[0594] The compound obtained in step 1 was subjected to nuclear magnetic resonance ( 1 The measured data are shown below.

[0595] 1 H-NMR (CDCl3, 300MHz): 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 compound was measured using a GC-MS detector (ITQ1100 ion trap GC / MS system, manufactured by ThermoFisher Scientific KK). Accordingly, a main peak with a molecular weight of 397.13 (EI+ mode) was measured, confirming the presence of the target substance, 3-(4-bromophenyl)-9-phenyl-9H-carbazole.

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

[0599] [Step 2: Synthesis 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 reacted in an organic solvent with heating and stirring using a palladium catalyst, a ligand for the palladium catalyst, and a base.

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

[0605] The obtained compound was subjected to nuclear magnetic resonance (NMR) measurement. The measurement results showed that the target substance 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP) was obtained in Comparative Example 3.

[0606] As described above, it was confirmed that the target substance can be easily obtained with a very high yield and high purity 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 contents of which are hereby incorporated 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 driver circuit, 402: pixel portion, 403: gate side driver circuit, 404: sealing substrate, 405: sealant; 407: spacer, 408: wire, 409: flexible printed circuit (FPC), 410: element 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: Separating layer, 511: First light-emitting unit, 512: Second light-emitting unit, 513: Charge generation layer, 521: First electrode, 522: Second electrode, 611: Housing, 612: Supporting substrate, 613: Display portion, 614: Speaker portion, 615: Viewfinder Audio input terminal, 621: Main body, 622: Housing, 623: Display part, 624: Keyboard, 625: External connection part, 626: Click device, 631: Main body, 632: Housing, 633: Display part, 634: Sound input part, 635: Sound output part, 636: Operation key, 637: External connection part, 638: Antenna, 641: Main body, 642: Display part, 643: Housing, 644: External connection part, 645: Remote control receiving part, 646: Image receiving part, 647: Remote control receiving part, 648: Remote control receiving part, 649: Remote control receiving part, 650: Remote control receiving part, 651: Remote control receiving part, 652: Remote control receiving part, 653: Remote control receiving part, 654: Remote control receiving part, 655: Remote control receiving part, 656: Remote control receiving part, 657: Remote control receiving part, 658: Remote control receiving part, 659: Remote control receiving part, 660: Remote control receiving part, 661: Remote control receiving part, 662: Remote control receiving part, 663: Remote control receiving part, 664: Remote control receiving part, 665: Remote control receiving part, 666: Remote control receiving part, 667: Remote control receiving part, 668: Remote control receiving part, 669: Remote control receiving part, 670: Remote control receiving part, 671: Remote control receiving part, 672: Remote control receiving part, 673: Remote control receiving part, 674: Remote control receiving part, 675: Remote control receiving part, 676: Remote control receiving part, 677: Remote control receiving part, 678: Remote control receiving part, 679: Remote control receiving part, 680: Remote control receiving part, 6 7; battery, 648: sound input portion, 649: operation key, 650: eyepiece portion, 701: casing, 702: liquid crystal layer, 703: backlight, 704: casing, 705: driver IC, 706: terminal, 801: casing, 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 compound represented by the general formula (G1), wherein Except for the following compounds (253): in: R 1 to R 8 Each independently represents a hydrogen atom; α 1 and α 2 each independently represents a substituted or unsubstituted phenylene group; Ar 1 represents a ring-forming aryl group having 6 to 13 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 or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; m and n are independently 0 or 1; J is 0, α 4 is a substituted or unsubstituted phenylene group; k is 1, except for the case of p-phenylene, α 3 is a substituted or unsubstituted phenylene group; When α 1 -α 4 、Ar 1 -Ar 3 When any one of the groups has a substituent, the substituent is any one of a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a phenyl group, a biphenyl group, and a naphthyl group.

2. A compound represented by the general formula (G1): in: R 1 to R 8 Each independently represents a hydrogen atom; α 1 and α 2 each independently represents a substituted or unsubstituted phenylene group; Ar 1 represents a ring-forming aryl group having 6 to 13 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 or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; m and n are independently 0 or 1; J is 0, α 4 is a substituted or unsubstituted phenylene group; k is 1, except for the case of p-phenylene, α 3 is a substituted or unsubstituted phenylene group; When α 1 -α 4 、Ar 1 -Ar 3 When any one of the groups has a substituent, the substituent is any one of a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a phenyl group, a biphenyl group, and a naphthyl group.

3. A compound represented by the general formula (G1), wherein Except for the following compounds (253): in: R 1 to R 8 Each independently represents a hydrogen atom; α 1 and α 2 each independently represents a substituted or unsubstituted phenylene group; Ar 1 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 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 or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; m and n are independently 0 or 1; J is 0, α 4 is a substituted or unsubstituted phenylene group; k is 1, except for the case of p-phenylene, α 3 is a substituted or unsubstituted phenylene group; When α 1 -α 4 、Ar 1 -Ar 3 When any one of the groups has a substituent, the substituent is any one of a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a phenyl group, a biphenyl group, and a naphthyl group.

4. A compound represented by the general formula (G1): in: R 1 to R 8 Each independently represents a hydrogen atom; α 1 and α 2 each independently represents a substituted or unsubstituted phenylene group; Ar 1 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 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 or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; m and n are independently 0 or 1; J is 0, α 4 is a substituted or unsubstituted phenylene group; k is 1, except for the case of p-phenylene, α 3 is a substituted or unsubstituted phenylene group; When α 1 -α 4 、Ar 1 -Ar 3 When any one of the groups has a substituent, the substituent is any one of a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a phenyl group, a biphenyl group, and a naphthyl group.

5. A compound represented by the general formula (G1): in: R 1 to R 8 Each independently represents a hydrogen atom; α 1 and α 2 each independently represents a substituted or unsubstituted phenylene group; Ar 1 represents a ring-forming aryl group having 6 to 13 carbon atoms; Ar 2 represents any one of 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 or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; m and n are independently 0 or 1; J is 0, α 4 is a substituted or unsubstituted phenylene group; k is 1, except for the case of p-phenylene, α 3 is a substituted or unsubstituted phenylene group; When α 1 -α 4 、Ar 1 -Ar 3 When any one of the groups has a substituent, the substituent is any one of a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a phenyl group, a biphenyl group, and a naphthyl group.

6. A compound represented by the general formula (G1): in: R 1 to R 8 Each independently represents a hydrogen atom; α 1 and α 2 each independently represents a substituted or unsubstituted phenylene group; Ar 1 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 2 represents any one of 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 or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; m and n are independently 0 or 1; J is 0, α 4 is a substituted or unsubstituted phenylene group; k is 1, except for the case of p-phenylene, α 3 is a substituted or unsubstituted phenylene group; When α 1 -α 4 、Ar 1 -Ar 3 When any one of the groups has a substituent, the substituent is any one of a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a phenyl group, a biphenyl group, and a naphthyl group.

7. The compound according to any one of claims 1 to 6, wherein Ar 3 Any one of the substituents represented by the following formulas (Ar3-6) to (Ar3-8) 8 . A light-emitting element comprising the compound according to claim 1 .

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