JP2010097964A - Organic electric field light emitting device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electric field light emitting device whose life characteristics are improved. <P>SOLUTION: The organic electric field light emitting device includes an organic layer 20 between a positive electrode 11 and a negative electrode 31. The organic layer 20 has the structure in which a hole injection layer 21, a hole transportation layer 22, a light emitting layer 23, and an electron transportation layer 24 are stacked, starting from the positive electrode 11 side. The hole injection layer 21 includes a first hole injection layer 21A having aniline derivative and organic acid, and a second hole injection layer 21B having thiophene derivative and organic acid. The hole transportation layer 22 contains 7-(N'-carbazole)-N,N-diphenyl-9H-fluorene-2-amine, and the like. When the organic layer 20 is applied with an electric field, a hole is sufficiently injected into the light emitting layer 23 form the positive electrode 11 with efficiency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescent element used for a color display or the like and a display device using the same.

  In recent years, technologies related to organic electroluminescence (organic EL), organic solar cells, organic transistors, or organic memories that use organic materials in thin films for displays, batteries, transistors, or recording devices, so-called organic electronics, have attracted attention. .

  Among these, the organic EL is attracting attention as a next-generation display technology. Specifically, in 1987, Tan et al. Of Eastman Kodak Co., Ltd. announced an organic electroluminescence device capable of low-voltage driving and high-intensity light emission having a laminated structure having an amorphous light-emitting layer. This organic electroluminescent element includes an organic layer between an anode and a cathode, and for example, the organic layer has a laminated structure including a hole transport layer, a light emitting layer, an electron transport layer, and the like.

  Since then, research and development on organic electroluminescent devices have been actively conducted, but as a display used for a long life, the light emission life is short and sufficient life characteristics have not been obtained. Then, the organic material (organic EL material) used for an organic layer for the purpose of the improvement of a lifetime characteristic, especially the positive hole transport material used for a positive hole transport layer are examined. Specifically, a technique using a carbazole derivative as a hole transport material has been proposed (see, for example, Patent Documents 1 to 4).

  As a result of such research on organic EL materials, it has become possible to secure sufficient life characteristics for use as a display for a mobile phone or MP3 player or a viewfinder for a camcorder. As a result, commercialization has been promoted as a display for in-vehicle audio use or mobile device use, but the display life as a display for a television such as a CRT or a liquid crystal display has not been reached. For this reason, the organic electroluminescent element used for the home use display apparatus which replaces a CRT, a plasma display, or a liquid crystal display is improved further, improving a lifetime characteristic.

  As an organic electroluminescent element used in this display device, a top emission type organic electroluminescent element is known. Specifically, for example, as shown in FIG. 3, a light-reflective anode 103, an organic layer 104, and a light-transmitting property are provided on a driving substrate 102 having a driving circuit such as a thin film transistor (TFT). The cathodes 105 are stacked in this order. For example, the organic layer 104 has a configuration in which a hole transport layer 104A, a light emitting layer 104B, and an electron transport layer 104C are stacked in this order from the anode 103 side. Accordingly, emitted light can be extracted from the opposite side (cathode 105 side) of the drive substrate 102 including the drive circuit, which is advantageous in improving the aperture ratio of the light emitting portion. Due to this improvement in aperture ratio, even if the current density applied to the organic electroluminescent element is kept low, sufficient light emission luminance can be obtained, which leads to improvement in the life characteristics.

  The anode in such a top emission type organic electroluminescent element is made of a material having high reflectivity in order to efficiently extract emitted light from the cathode side. As this material, for example, it has been proposed to use silver or an alloy containing silver (see, for example, Patent Document 5). However, when a material such as silver is used for the anode, problems such as short-circuit due to hillocks and disconnection due to migration are likely to occur during driving, particularly during high-temperature driving.

  Therefore, it has been studied to use an aluminum alloy containing aluminum as a main component as a material of the anode. In this case, in order to compensate for the relatively small work function of aluminum, an aluminum alloy containing about 10% by weight of copper, palladium, gold, platinum or the like having a high work function is used as a secondary component metal. In addition, as a material for the anode, it has been proposed to use neodymium or the like that has aluminum as a main component and is cheaper than platinum as a subcomponent metal and relatively lower than the work function of aluminum (for example, (See Patent Document 6). In this case, it is also disclosed that azatriphenylene or a triphenylene derivative is used as a material for the hole injection layer provided on the anode.

  By the way, each layer constituting the organic layer of the organic electroluminescence device is usually formed by a vapor phase method such as a vacuum evaporation method. In this case, for example, when a foreign substance exists on the anode, an organic layer is formed on the foreign substance, so that a portion (non-covered portion) that is not covered with the anode is generated. When a cathode is provided on the non-covered portion, a short circuit occurs between the anode and the cathode in the non-covered portion, and no light is emitted from the pixel where the short circuit occurs. As a result, there is a problem that the production yield is likely to decrease. In addition, since an apparatus for forming a film by a vapor phase method is expensive, there is a problem of high cost.

Therefore, in order to solve the above-described manufacturing problems, it has been proposed to form an organic layer by a coating method. Specifically, for example, a method of forming a hole injection layer on the anode by a coating method using a mixture of a polythiophene derivative called PEDOT and an organic acid such as a polystyrene sulfonic acid derivative as a hole injection material (For example, see Non-Patent Document 1).
Japanese Patent No. 3649302 JP 11-329737 A JP 2003-229279 A JP 2005-158691 A JP 2003-234193 A JP 2006-079836 A B. W. D'Andrad, M.M. E. Thompson, S.M. R. Forest, Adv. Mater. , 14, 147 (2002)

  However, when the layer containing the polythiophene derivative and polystyrene sulfonic acid described above is used as the hole injection layer, the emission lifetime is likely to be short, and it is difficult to obtain sufficient lifetime characteristics. This also applies to the case where the azatriphenylene or triphenylene derivative described in Patent Document 6 is used as the hole injection material.

  The present invention has been made in view of such problems, and an object thereof is to provide an organic electroluminescent element and a display device capable of improving life characteristics.

  The organic electroluminescent element of the present invention includes an organic layer including a light emitting layer between an anode and a cathode, and the organic layer includes a thiophene derivative and an organic acid in order from the anode side between the anode and the light emitting layer. A first layer including the first layer, and a second layer including at least one of the compounds represented by the formulas (1) and (2). The display device of the present invention includes the organic electroluminescent element of the present invention.

（Ｒ１およびＲ２は各々独立して芳香族炭素環基あるいは芳香族複素環基、またはそれらに１あるいは２以上の置換基が導入された基である。Ｒ３〜Ｒ１０は各々独立して水素原子、ハロゲン原子、アルキル基、アラルキル基、アルケニル基、シアノ基、アミノ基、アシル基、アルコキシカルボニル基、カルボキシル基、アルコキシ基、アリールオキシ基、アルキルスルホニル基、水酸基、アミド基、芳香族炭素環基あるいは芳香族複素環基、またはそれらに１あるいは２以上の置換基が導入された基であり、Ｒ３〜Ｒ１０のうちの隣り合うもの同士は結合して環構造を形成してもよい。Ｌ１は、２価の芳香族炭素環基、置換基を有する２価の芳香族炭素環基、２価の芳香族複素環基および置換基を有する２価の芳香族複素環基のうちの少なくとも１種が１つ〜４つ連結してなる連結基である。）

(R1 and R2 are each independently an aromatic carbocyclic group or an aromatic heterocyclic group, or a group having one or more substituents introduced therein. R3 to R10 are each independently a hydrogen atom, Halogen atom, alkyl group, aralkyl group, alkenyl group, cyano group, amino group, acyl group, alkoxycarbonyl group, carboxyl group, alkoxy group, aryloxy group, alkylsulfonyl group, hydroxyl group, amide group, aromatic carbocyclic group or An aromatic heterocyclic group, or a group in which one or two or more substituents are introduced thereto, and adjacent ones of R3 to R10 may be bonded to form a ring structure. Among the divalent aromatic carbocyclic group, the divalent aromatic carbocyclic group having a substituent, the divalent aromatic heterocyclic group, and the divalent aromatic heterocyclic group having a substituent are few. Both one is one to four linked formed by linking group.)

（Ｘ１はＮ−カルバゾイル基、Ｎ−フェノキサジイル基あるいはＮ−フェノチアジイル基または、それらに１あるいは２以上の置換基が導入された基である。Ｘ２はＮ−カルバゾイル基、Ｎ−フェノキサジイル基、Ｎ−フェノチアジイル基、あるいはそれらに１もしくは２以上の置換基が導入された基、または−Ｎ（Ｙ１）（Ｙ２）−であり、Ｙ１およびＹ２は芳香族炭素環基あるいは芳香族複素環基またはそれらに１あるいは２以上の置換基が導入された基である。Ｒ１１およびＲ１２は各々独立して水素原子、アルキル基、芳香族炭素環基、芳香族複素環基あるいはアラルキル基、またはそれらに１あるいは２以上の置換基が導入された基である。Ｒ１３およびＲ１４は各々独立して水素原子、ハロゲン原子、アルキル基、アルコキシ基、芳香族炭素環基あるいは芳香族複素環基、またはそれらに１あるいは２以上の置換基が導入された基である。）

(X1 is an N-carbazoyl group, N-phenoxadiyl group or N-phenothiadiyl group, or a group in which one or more substituents are introduced. X2 is an N-carbazoyl group, N-phenoxadiyl group. A group, an N-phenothiadiyl group, a group into which one or more substituents are introduced, or -N (Y1) (Y2)-, wherein Y1 and Y2 are aromatic carbocyclic groups or aromatic heterocyclic rings R11 and R12 each independently represents a hydrogen atom, an alkyl group, an aromatic carbocyclic group, an aromatic heterocyclic group or an aralkyl group, or And R13 and R14 each independently represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group. Aromatic carbocyclic group or aromatic heterocyclic group, or a thereof to 1 or 2 or more substituents are introduced group.)

In the organic electroluminescent element and the display device of the present invention, the organic layer includes a first layer containing a thiophene derivative and an organic acid in order from the anode side between the anode and the light emitting layer, and the formulas (1) and ( 2) A second layer containing at least one of the compounds shown is stacked. Thus, when an electric field is applied between the two electrodes, the first layer efficiently injects holes into the second layer, and the holes injected by the second layer are efficiently transported to the light emitting layer. To do. In this way, the holes moved from the anode side and the electrons transported from the cathode side are recombined in the light emitting layer to emit light. In this case, if free protons (H ⁺ ) are contained in the first layer, the protons move with the holes. Here, if the second layer is not provided, protons diffuse into the light-emitting layer, and the light emission efficiency is lowered to make it difficult to maintain sufficient light emission intensity. However, by having the second layer, The second layer captures protons and efficiently transports holes to the light emitting layer. For this reason, even if it drives for a long time, the fall of luminous efficiency is suppressed.

  According to the organic electroluminescent element or the display device of the present invention, the organic layer is provided with the first layer and the second layer in order from the anode side between the anode and the light emitting layer. Therefore, even when driven for a long time, the light emission intensity is maintained well and the life characteristics can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The order of explanation is as follows.
1. Organic electroluminescence device (example of top emission type)
2. Display device (example of using organic electroluminescent elements)
3. Modified example

[1. Organic electroluminescence device (example of top emission type)]
FIG. 1 shows a cross-sectional configuration of an organic electroluminescent element according to an embodiment of the present invention. This organic electroluminescent element (organic EL element) is used in a display device such as a color display, for example. This organic electroluminescent element is equipped with the anode 11, the organic layer 20, and the cathode 31 in this order on the board | substrate 10, for example. The organic layer 20 has a structure in which a hole injection layer 21, a hole transport layer 22, a light emitting layer 23, and an electron transport layer 24 are stacked in this order from the anode 11 side. Here, a case of a top emission type organic electroluminescent element in which light emitted from the light emitting layer 23 (hereinafter referred to as emitted light) is extracted from the cathode 31 side will be described.

  The substrate 10 includes, for example, a transparent substrate such as glass, a silicon substrate, a film-like flexible substrate, and the like. Further, the substrate 10 may be one in which a driving circuit such as a TFT is provided for each pixel when the driving method of the display device configured using the organic electroluminescent element is an active matrix method. In this case, the substrate 10 is provided with anodes 11 in a matrix for each pixel, whereby each pixel is driven independently in an active matrix display device.

  The anode 11 is preferably formed so as to reflect substantially all the wavelength components of visible light. Examples of the material constituting the anode 11 include nickel, silver, gold, platinum, palladium, selenium, rhodium, ruthenium, iridium, rhenium, tungsten, molybdenum, chromium, tantalum, niobium, or one or two of these. Examples include alloys containing at least species and oxides thereof, and other examples include tin oxide, ITO, zinc oxide, and titanium oxide. These may be used alone or in combination.

  In particular, the material constituting the anode 11 is preferably an alloy containing aluminum as a main component and an element having an element having a relatively lower work function than aluminum as an accessory component (hereinafter referred to as an aluminum alloy). This is because the reflectance is high and it is relatively inexpensive. As an auxiliary component contained in the aluminum alloy, a lanthanoid series element is preferable. This is because the work function of the lanthanoid series element is not large, but the inclusion of this element improves the stability of the anode 11 and provides sufficient hole injection properties. In addition, the aluminum alloy may contain silicon, copper, or the like as a subcomponent in addition to the lanthanoid series element. The content of subcomponent elements contained in the aluminum alloy is preferably 10% by weight or less. This is because good reflectivity is obtained, conductivity is high, and adhesion with the substrate 10 is also high. Moreover, when manufacturing an organic electroluminescent element, the reflectance is maintained favorably and stably, and high processing accuracy and chemical stability are obtained.

  Moreover, when using said aluminum alloy as a constituent material, the anode 11 may be formed by the some layer, for example. Specifically, the layer containing the aluminum alloy may be a first layer, and a two-layer structure in which a second layer having excellent light transmittance is provided on the organic layer 20 side. As the material constituting the second layer having excellent light transmittance, the above-mentioned aluminum alloy oxide, tungsten oxide, molybdenum oxide, zirconium oxide, chromium oxide, tantalum oxide , Vanadium oxide, tin oxide, zinc oxide, ITO or IZO. In particular, the oxide of the aluminum alloy is naturally formed by forming the first layer containing the aluminum alloy and then oxidizing the surface of the first layer unless it is kept in an ultrahigh vacuum. For this reason, it is preferable because a film forming process such as a vacuum evaporation method or a sputtering method is not necessary. In addition, a layer containing an aluminum alloy is used as a first layer, and a second layer having conductivity is formed between the first layer and the substrate 10 in order to improve the adhesion between the anode 11 and the substrate 10. May be. Examples of the material constituting the second layer having conductivity include transparent conductive materials such as ITO and IZO. The anode 11 may have both the two-layer structure described above. That is, a conductive layer for improving adhesion to the substrate 10, a layer containing the above-described aluminum alloy provided thereon, and a layer having excellent light transmittance provided thereon It is good also as a three-layer structure provided with.

  The hole injection layer 21 provided in the organic layer 20 is for efficiently injecting holes generated in the anode 11 into the hole transport layer 22. The hole injection layer 21 has, for example, a two-layer structure, and a first hole injection layer 21A and a second hole injection layer 21B are stacked in order from the anode 11 side.

  The first hole injection layer 21A contains an aniline derivative and an organic acid. In the present embodiment, the first hole injection layer 21 is not essential, but is preferably provided from the viewpoint of improving the life characteristics. If the first hole injection layer 21A is not provided, a layer (second hole injection layer 21B) containing a thiophene derivative and an organic acid described later is provided on the anode 11. When the material used for forming the layer containing the thiophene derivative and the organic acid shows strong acidity, the anode 11 is corroded if the anode 11 contains a material having low acid resistance such as an aluminum alloy. It becomes easy. Thereby, there exists a possibility that the element characteristic containing a lifetime characteristic may fall. However, by providing the first hole injection layer 21A, even when the material used when forming the layer containing such a thiophene derivative and an organic acid shows strong acidity, Corrosion of the anode 11 is suppressed by the hole injection layer 21A. In addition, by providing the first hole injection layer 21A, the hole injection efficiency of the hole injection layer 21 is increased and is maintained well. Therefore, it is easy to obtain high life characteristics among element characteristics.

  As the aniline derivative, a polymer compound represented by the formula (7) is preferable, and as the organic acid, an organic acid represented by the formula (4), an organic acid represented by the formula (5) (fluorinated In addition, at least one of an organic acid (polystyrene sulfonic acid derivative) represented by formula (6) is preferable. Note that the aniline derivative is not limited to the polymer compound represented by the formula (7). Moreover, if it is an organic acid, it will not be limited to the organic acid shown to Formula (4)-Formula (6).

（Ｒ４１〜Ｒ４５は各々独立して水素原子、飽和炭化水素基、不飽和炭化水素基、飽和炭化水素オキシ基、不飽和炭化水素オキシ基、アリール基、置換基を有するアリール基、アリールオキシ基、置換基を有するアリールオキシ基、複素環基あるいは置換基を有する複素環基である。Ｌ４〜Ｌ６は各々独立してベンゼン環骨格あるいはナフタレン環骨格を有する２価の基である。ｌ、ｍおよびｎは各々独立して０以上の整数であり、（ｌ＋ｍ＋ｎ）≧１以上を満たす。）

(R41 to R45 are each independently a hydrogen atom, a saturated hydrocarbon group, an unsaturated hydrocarbon group, a saturated hydrocarbon oxy group, an unsaturated hydrocarbon oxy group, an aryl group, an aryl group having a substituent, an aryloxy group, An aryloxy group having a substituent, a heterocyclic group, or a heterocyclic group having a substituent, and L4 to L6 each independently represent a divalent group having a benzene ring skeleton or a naphthalene ring skeleton; Each n is independently an integer of 0 or more, and satisfies (l + m + n) ≧ 1.)

（Ｒ３１およびＲ３２は各々独立してカルボキシル基あるいは水酸基である。Ｂ１はベンゼン環、ナフタレン環、アントラセン環、フェナントレン環あるいは複素環を有する３価の基である。）

(R31 and R32 are each independently a carboxyl group or a hydroxyl group. B1 is a trivalent group having a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring or heterocyclic ring.)

（ｘ、ｙおよびｚは各々独立して１以上の整数である。）

(X, y and z are each independently an integer of 1 or more.)

（ｐは１以上の整数である。）

(P is an integer of 1 or more.)

  L4 to L6 described in formula (7) are arbitrary as long as they are divalent groups having a benzene ring skeleton or a naphthalene ring skeleton. It is preferably a divalent group having a benzene ring skeleton or a divalent group having a naphthalene skeleton represented by formulas (B-1) to (B-3).

（Ｒ５０〜Ｒ７５は各々独立して水素原子、飽和炭化水素基、不飽和炭化水素基、飽和炭化水素オキシ基、不飽和炭化水素オキシ基、アリール基、置換基を有するアリール基、アリールオキシ基、置換基を有するアリールオキシ基、複素環基、置換基を有する複素環基、アミノ基、置換基を有するアミノ基、アリールアミノ基、置換基を有するアリールアミノ基、シアノ基、ニトロ基、水酸基、ハロゲン原子、シラノール基、チオール基、スルホン酸基、リン酸基、リン酸エステル基あるいはカルボキシル基である。）

(R50 to R75 are each independently a hydrogen atom, a saturated hydrocarbon group, an unsaturated hydrocarbon group, a saturated hydrocarbon oxy group, an unsaturated hydrocarbon oxy group, an aryl group, an aryl group having a substituent, an aryloxy group, An aryloxy group having a substituent, a heterocyclic group, a heterocyclic group having a substituent, an amino group, an amino group having a substituent, an arylamino group, an arylamino group having a substituent, a cyano group, a nitro group, a hydroxyl group, A halogen atom, a silanol group, a thiol group, a sulfonic acid group, a phosphoric acid group, a phosphoric ester group or a carboxyl group.)

  As a high molecular compound shown in Formula (7), the high molecular compound represented by Formula (7-1) is mentioned, for example. That is, L4 and L5 in Formula (7) are the divalent groups shown in Formula (A-1), L6 is the divalent group shown in Formula (B-1), and R41 to R45. , R50 to R53 and R58 to R63 are all high molecular compounds that are hydrogen atoms. In addition, if it has the structure shown to Formula (7), it will not be limited to the high molecular compound shown to Formula (7-1).

（ｌ、ｍおよびｎは各々独立して０以上の整数であり、（ｌ＋ｍ＋ｎ）≧１以上を満たす。）

(L, m, and n are each independently an integer of 0 or more, and (l + m + n) ≧ 1 is satisfied.)

  Moreover, as a compound shown to Formula (4), the compound represented by Formula (4-1) is mentioned, for example. That is, R31 and R32 are a carboxyl group and a hydroxyl group, respectively, and B1 is a compound having a benzene ring. In addition, if it has the structure shown to Formula (4), it will not be limited to the compound shown to Formula (4-1).

  The second hole injection layer 21B contains a thiophene derivative and an organic acid. Thereby, hole injection efficiency becomes high and is maintained favorable. The second hole injection layer 21B is a specific example corresponding to the “first layer” in the claims.

  As this thiophene derivative, for example, a polymer compound represented by the formula (3) is preferable. Moreover, as this organic acid, at least 1 sort (s) of the compounds shown to said Formula (4)-Formula (6) is preferable. Note that the thiophene derivative is not limited to the polymer compound represented by the formula (3). The same applies to the organic acid used here.

（Ｒ２１は炭素数１〜５のアルキレン基、あるいは炭素数１〜５のアルキレン基に置換基が導入された２価の基である。Ｚ１は酸素原子あるいは硫黄原子である。ｑは１以上の整数である。）

(R21 is an alkylene group having 1 to 5 carbon atoms, or a divalent group in which a substituent is introduced into an alkylene group having 1 to 5 carbon atoms. Z1 is an oxygen atom or a sulfur atom. Q is 1 or more. (It is an integer.)

  R21 described in formula (3) is arbitrary as long as it has a carbon skeleton of an alkylene group having 1 to 5 carbon atoms, and among them, an alkylene group having 2 or 3 carbon atoms is preferable. This is because it is easily available and a high effect can be obtained.

  Examples of the polymer compound represented by the formula (3) include a polymer compound represented by the formula (3-1). In addition, if it has the structure shown to Formula (3), it will not be limited to the high molecular compound shown to Formula (3-1).

（ｑは１以上の整数である。）

(Q is an integer of 1 or more.)

  Examples of a method for forming each layer of the hole injection layer 21 (first hole injection layer 21A, second hole injection layer 21B) include a vapor phase method such as a vacuum deposition method, a wet method, and the like. Of these, the wet method is preferable. This is because the material forming each layer has solubility in a solvent, and even if there is a foreign matter on the anode 11, short-circuiting by the foreign matter is suppressed. Specifically, the film using the wet method can satisfactorily cover the anode 11 so that an uncovered portion does not occur even if there is a foreign matter on the anode 11. For this reason, generation | occurrence | production of the short circuit between electrodes which may be produced by the non-coating part of an organic film at the time of formation of the cathode 31 is suppressed, and it becomes difficult to produce non-light emission by this. Therefore, the yield can be improved and the cost can be reduced. Further, the cost can be reduced as compared with a vapor phase method such as a vacuum evaporation method. As this wet method, for example, a general method such as a spin coating method, a dip coating method, an ink jet method, or a spray method can be used. Examples of the solvent used when forming each layer by this wet method include phenol, cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, triethylene glycol, and the like. Propylene glycol, 1,3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol, water, methanol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylformanilide, N, N′-dimethylimidazolidinone, dimethyl sulfoxide, chloroform, toluene, ethanol, butyl cellosolve, diethylene glycol diethyl ether, dipropylene group Glycol monomethyl ether, ethyl carbitol, diacetone alcohol, .gamma.-butyrolactone and ethyl lactate or methyl ethyl ketone. These may be used singly or as a mixture of a plurality of types as required for the forming step and the film thickness control of each layer.

  The hole transport layer 22 is for efficiently transporting the holes injected from the hole injection layer 21 to the light emitting layer 23, and is made of the compounds represented by the formulas (1) and (2). Includes at least one. Thereby, even if the hole injection layer 21 (particularly, the second hole injection layer 21B) contains a liberated proton and the proton moves together with the hole, the hole transport layer 22 captures the proton, and the light emitting layer 23 Suppresses proton transfer to In addition, since the hole transport efficiency is maintained well, the life characteristics are improved. The hole transport layer 22 is a specific example corresponding to the “second layer” in the claims.

（Ｒ１およびＲ２は各々独立して芳香族炭素環基あるいは芳香族複素環基、またはそれらに１あるいは２以上の置換基が導入された基である。Ｒ３〜Ｒ１０は各々独立して水素原子、ハロゲン原子、アルキル基、アラルキル基、アルケニル基、シアノ基、アミノ基、アシル基、アルコキシカルボニル基、カルボキシル基、アルコキシ基、アリールオキシ基、アルキルスルホニル基、水酸基、アミド基、芳香族炭素環基あるいは芳香族複素環基、またはそれらに１あるいは２以上の置換基が導入された基であり、Ｒ３〜Ｒ１０のうちの隣り合うもの同士は結合して環構造を形成してもよい。Ｌ１は、２価の芳香族炭素環基、置換基を有する２価の芳香族炭素環基、２価の芳香族複素環基および置換基を有する２価の芳香族複素環基のうちの少なくとも１種が１つ〜４つ連結してなる連結基である。）

(R1 and R2 are each independently an aromatic carbocyclic group or an aromatic heterocyclic group, or a group having one or more substituents introduced therein. R3 to R10 are each independently a hydrogen atom, Halogen atom, alkyl group, aralkyl group, alkenyl group, cyano group, amino group, acyl group, alkoxycarbonyl group, carboxyl group, alkoxy group, aryloxy group, alkylsulfonyl group, hydroxyl group, amide group, aromatic carbocyclic group or An aromatic heterocyclic group, or a group in which one or two or more substituents are introduced thereto, and adjacent ones of R3 to R10 may be bonded to form a ring structure. Among the divalent aromatic carbocyclic group, the divalent aromatic carbocyclic group having a substituent, the divalent aromatic heterocyclic group, and the divalent aromatic heterocyclic group having a substituent are few. Both one is one to four linked formed by linking group.)

（Ｘ１はＮ−カルバゾイル基、Ｎ−フェノキサジイル基あるいはＮ−フェノチアジイル基または、それらに１あるいは２以上の置換基が導入された基である。Ｘ２はＮ−カルバゾイル基、Ｎ−フェノキサジイル基、Ｎ−フェノチアジイル基、あるいはそれらに１もしくは２以上の置換基が導入された基、または−Ｎ（Ｙ１）（Ｙ２）−であり、Ｙ１およびＹ２は芳香族炭素環基あるいは芳香族複素環基またはそれらに１あるいは２以上の置換基が導入された基である。Ｒ１１およびＲ１２は各々独立して水素原子、アルキル基、芳香族炭素環基、芳香族複素環基あるいはアラルキル基、またはそれらに１あるいは２以上の置換基が導入された基である。Ｒ１３およびＲ１４は各々独立して水素原子、ハロゲン原子、アルキル基、アルコキシ基、芳香族炭素環基あるいは芳香族複素環基、またはそれらに１あるいは２以上の置換基が導入された基である。）

(X1 is an N-carbazoyl group, N-phenoxadiyl group or N-phenothiadiyl group, or a group in which one or more substituents are introduced. X2 is an N-carbazoyl group, N-phenoxadiyl group. A group, an N-phenothiadiyl group, a group into which one or more substituents are introduced, or -N (Y1) (Y2)-, wherein Y1 and Y2 are aromatic carbocyclic groups or aromatic heterocyclic rings R11 and R12 each independently represents a hydrogen atom, an alkyl group, an aromatic carbocyclic group, an aromatic heterocyclic group or an aralkyl group, or And R13 and R14 each independently represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group. Aromatic carbocyclic group or aromatic heterocyclic group, or a thereof to 1 or 2 or more substituents are introduced group.)

  First, the compound shown in Formula (1) is demonstrated.

  R1 and R2 described in formula (1) are arbitrary as long as they are any of the groups described above. Examples of the aromatic carbocyclic group introduced as R1 and R2 include a group consisting of a monocyclic benzene ring or 2 to 5 condensed rings. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, and a perylenyl group. Examples of the aromatic heterocyclic group introduced as R1 and R2 include a 5-membered ring or a 6-membered monocyclic ring or a 2-5 condensed ring. Specific examples include a pyridyl group, a triazinyl group, a pyrazinyl group, a quinoxalinyl group, and a thienyl group.

  Moreover, as a substituent which the aromatic carbocyclic group and aromatic heterocyclic group introduce | transduced as R1, R2 have, for example, alkyl group (For example, a C1-C6 straight chain, such as a methyl group and an ethyl group, or A branched alkyl group), an alkenyl group (for example, a linear or branched alkenyl group having 1 to 6 carbon atoms such as a vinyl group or an allyl group), an alkoxycarbonyl group (for example, a carbon number such as a methoxycarbonyl group or an ethoxycarbonyl group). 1 to 6 linear or branched alkoxycarbonyl groups), alkoxy groups (for example, methoxy or ethoxy groups such as linear or branched alkoxy groups having 1 to 6 carbon atoms), aryloxy groups (for example, phenoxy groups or Aryloxy groups having 6 to 10 carbon atoms such as naphthoxy group), aralkyloxy groups (for example, benzil Aralkyloxy group having 7 to 13 carbon atoms such as oxy group), secondary or tertiary amino group (for example, dialkylamino having a linear or branched alkyl group having 2 to 20 carbon atoms such as diethylamino group or diisopropylamino group) Group, diarylamino group such as diphenylamino group or phenylnaphthylamino group, arylalkylamino group having 7 to 20 carbon atoms such as methylphenylamino group), halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom), An aromatic carbocyclic group (for example, an aromatic carbocyclic group having 6 to 10 carbon atoms such as a phenyl group or a naphthyl group), or an aromatic heterocyclic group (for example, a 5-membered ring or 6-membered group such as a thienyl group or a pyridyl group) An aromatic heterocyclic group composed of a monocyclic ring or a double condensed ring). Among them, an alkyl group, an alkoxy group, an alkylamino group, an arylamino group, an arylalkylamino group, a halogen atom, an aromatic carbocyclic group or an aromatic heterocyclic group are preferable, and an alkyl group, an alkoxy group or an arylamino group is particularly preferable. .

  R1 and R2 preferably have three or more aromatic groups such as a terphenyl group and do not include a structure in which the aromatic groups are linked via two or more direct bonds. This is because the following can be considered. When R1 and R2 include this structure, the intermolecular distance in the hole transport layer 22 is long (separated) due to the arylamino group represented by —N (R1) (R2) in formula (1). It tends to be formed, and as a result, the hole transport ability may be reduced. Moreover, by having the arylamino group, the glass transition point (Tg) of the compound represented by the formula (1) can be easily lowered. Therefore, in order for the hole transport layer 22 to exhibit higher hole transport ability, it is preferable that the compound represented by the formula (1) does not include the above structure as R1 and R2.

  R3 to R10 described in the formula (1) are arbitrary as long as they are any of the groups described above. Examples of R3 to R10 include the following groups in addition to a hydrogen atom, a cyano group, a carboxyl group, and a hydroxyl group. That is, the halogen atom is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. The alkyl group is a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group, or a cycloalkyl group having 5 to 8 carbon atoms such as a cyclopentyl group or a cyclohexyl group. The aralkyl group is an aralkyl group having 7 to 13 carbon atoms such as a benzyl group or a phenethyl group. The alkenyl group is a linear or branched alkenyl group having 2 to 7 carbon atoms such as a vinyl group or an allyl group. The amino group may be a dialkylamino group having a linear or branched alkyl group having 2 to 20 carbon atoms such as a diethylamino group or a diisopropylamino group, a diarylamino group such as a diphenylamino group or a phenylnaphthylamino group, or methylphenylamino. And a C7-20 arylalkylamino group such as a group. The acyl group includes an acyl group containing a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms such as an acetyl group, a propionyl group, a benzoyl group or a naphthoyl group. The alkoxycarbonyl group is a linear or branched alkoxycarbonyl group having 2 to 7 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group. The alkoxy group is a linear or branched alkoxy group having 1 to 6 carbon atoms such as a methoxy group or an ethoxy group. The aryloxy group is an aryloxy group having 6 to 10 carbon atoms such as a phenoxy group or a benzyloxy group. The alkylsulfonyl group is an alkylsulfonyl group having 1 to 6 carbon atoms such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, a butylsulfonyl group, or a hexylsulfonyl group. The amide group is an alkylamide group having 2 to 7 carbon atoms such as a methylamide group, a dimethylamide group or a diethylamide group, or an arylamide group such as a benzylamide group or a dibenzylamide group. The aromatic carbocyclic group is a monocyclic benzene ring such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group or a pyrenyl group, or an aromatic carbocyclic group composed of 2 to 4 condensed rings. The aromatic heterocyclic group is an aromatic heterocyclic group consisting of a 5-membered or 6-membered monocyclic ring or a 2-3 condensed ring such as a carbazolyl group, pyridyl group, triazyl group, pyrazyl group, quinoxalyl group or thienyl group. is there.

  R3 to R10 may be a group in which one or two or more substituents are introduced into the above-described group. Examples of the substituent to be introduced include, for example, a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom), an alkyl group (for example, a straight chain or branched chain having 1 to 6 carbon atoms such as a methyl group or an ethyl group). Alkyl group), alkenyl group (for example, linear or branched alkenyl group having 1 to 6 carbon atoms such as vinyl group or allyl group), alkoxycarbonyl group (for example, methoxycarbonyl group or ethoxycarbonyl group having 1 to 1 carbon atoms) 6 straight-chain or branched alkoxycarbonyl groups), alkoxy groups (for example, straight-chain or branched alkoxy groups having 1 to 6 carbon atoms such as methoxy group or ethoxy group), aryloxy groups (for example, phenoxy group or naphthoxy group) An aryloxy group having 6 to 10 carbon atoms), a dialkylamino group (for example, Dialkylamino group having a linear or branched alkyl group having 2 to 20 carbon atoms such as ethylamino group or diisopropylamino group), diarylamino group (diarylamino group such as diphenylamino group or phenylnaphthylamino group), aromatic Carbocyclic groups (for example, aromatic carbocyclic groups such as phenyl groups), aromatic heterocyclic groups (for example, aromatic heterocyclic groups composed of 5-membered or 6-membered monocycles such as thienyl groups or pyridyl groups) An acyl group (for example, a linear or branched acyl group having 1 to 6 carbon atoms such as an acetyl group or a propionyl group), a haloalkyl group (for example, a linear or branched haloalkyl having 1 to 6 carbon atoms such as a trifluoromethyl group) Group) or a cyano group. Among these, a halogen atom, an alkoxy group, or an aromatic carbocyclic group is more preferable.

  Further, as described in the formula (1), R3 to R10 may be bonded together to form a ring structure. In this case, the N-carbazolyl group in the formula (1) further has a condensed ring. The ring structure formed in this case is arbitrary, but the number of members may be a 5-membered ring to an 8-membered ring, preferably a 5-membered ring or a 6-membered ring, and is a 6-membered ring. Is more preferable. Further, the kind of the ring structure formed in this case may be an aromatic ring or a non-aromatic ring, but is preferably an aromatic hydrocarbon ring. Examples of the N-carbazolyl group having a condensed ring when adjacent groups of R1 to R8 are bonded include groups represented by formulas (C-1) to (C-4). It is done.

  As R3 to R10, among them, a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aromatic carbocyclic group or an aromatic heterocyclic group is preferable, and a hydrogen atom, a methyl group, a methoxy group or a phenyl group is particularly preferable. Specifically, it is preferable that all of R3 to R10 are hydrogen atoms, or any one or more of R3 to R10 are a methyl group, a methoxy group, or a phenyl group, and the others are hydrogen atoms.

  L1 explained in the formula (1) is arbitrary as long as it is a linking group formed by bonding 1 to 4 divalent groups containing an aromatic skeleton. As this L1, for example, a group represented by -Ar1-, -Ar2-Ar3-, -Ar4-Ar5-Ar6-, or -Ar7-Ar8-Ar9-Ar10- is preferable. In this case, Ar1, Ar2, Ar3, Ar4, Ar6, Ar7 and Ar10 constituting the terminal of L1 are divalent groups consisting of a monocyclic or 2-5 condensed ring of 5 or 6 aromatic rings, or those Represents a group in which a substituent is introduced, and Ar6, Ar7 and Ar10 among them are divalent aromatic rings having 5 or 6 members which may be substituted, or a divalent ring consisting of 2 to 5 condensed rings. -N (Ar11)-(Ar11 is a monovalent aromatic carbocyclic group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent. ).

  Ar1, Ar2, Ar3, Ar4, Ar6, Ar7 and Ar10 are divalent aromatic carbocyclic groups such as a phenylene group, a naphthylene group, an anthrylene group, a phenanthrylene group, a pyrenylene group and a peryleneylene group, or one or more of them. Or a divalent aromatic heterocyclic group such as a pyridylene group, triadylene group, pyrazylene group, quinoxalylene group, thienylene group or oxadiazolylene group, or one or more substituents thereof. Introduced groups are mentioned.

  In addition, as Ar1 which is the smallest linking group as the linking group L1 in the above case, in order to improve the rigidity of the compound represented by the formula (1) and the heat resistance resulting therefrom, three or more condensed rings are used. It is preferable that

  Moreover, as Ar2, Ar3, Ar4, Ar6, Ar7 and Ar10, a monocyclic ring, a bicondensed ring or a tricondensed ring is preferable, and a monocyclic ring or a bicondensed ring is more preferable.

  In addition, Ar5, Ar8 and Ar9 constituting the center of the linking group L1 in the above case are divalent aromatic groups represented by the groups described above as Ar1 and the like constituting the terminal, or —N (Ar11 )-Is a divalent arylamino group (Ar11 is a monovalent aromatic carbocyclic group or aromatic heterocyclic group which may have a substituent). Ar11 includes, for example, a 5- or 6-membered aromatic group such as a phenyl group, a naphthyl group, an anthryl group, a phenanthyl group, a thienyl group, a pyridyl group, a carbazolyl group, or one or more substituents. Examples include introduced groups.

  Ar5, Ar8 and Ar9 are preferably groups consisting of an aromatic carbocyclic ring or an aromatic heterocyclic ring from the viewpoint of improving heat resistance. Furthermore, Ar5, Ar8 and Ar9 are preferably —N (Ar11) — from the viewpoint of improving the amorphous property of the compound represented by the formula (1). In addition, when one of Ar8 and Ar9 is -N (Ar11)-, the other is preferably a group composed of an aromatic ring.

  Examples of the substituent that Ar1 to Ar10 have in addition to the aromatic skeleton include the same groups as the substituents introduced into R1 to R8 described above when they further have a substituent. Among these, an alkyl group, an alkoxy group, an aromatic carbocyclic group or an aromatic heterocyclic group is particularly preferable.

  Examples of the substituent introduced into the aromatic skeleton possessed by Ar11 include the same groups as the substituents introduced into R3 to R10 described above further having a substituent. Among them, an aromatic carbocyclic group such as an arylamino group, a phenyl group or a naphthyl group, or an aromatic heterocyclic group such as a carbazolyl group is particularly preferable.

  As a compound shown to Formula (1) demonstrated above, the compound represented by Formula (1-1)-Formula (1-26) is mentioned, for example.

  Next, the compound represented by formula (2) will be described.

  X1 and X2 described in the formula (2) are arbitrary as long as they are groups described above. When X1 and X2 are an N-carbazoyl group, an N-phenoxadiyl group or an N-phenothiadiyl group, they may be unsubstituted or substituted with other substituents. When they are substituted with other substituents, that is, when one or more substituents are introduced to them, examples of the introduced substituents include halogen atoms, carbons Examples thereof include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

  When X1 and X2 are an N-carbazoyl group, an N-phenoxadiyl group, an N-phenothiadiyl group, or a group into which one or more substituents are introduced, X1, X2 is an N-carbazoyl group, 1 or 2 of N-phenoxadiyl group or N-phenothiadiyl group, or a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms as a substituent. The N-carbazoyl group, N-phenoxadiyl group or N-phenothiadiyl group introduced above is preferable. In this case, among them, an N-carbazoyl group, an N-phenoxadiyl group or an N-phenothiadiyl group, or a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a carbon number having 6 to 10 carbon atoms. N-carbazoyl group, N-phenoxadiyl group or N-phenothiadiyl group in which one or two or more aryl groups are introduced is preferable. In this case, an N-carbazoyl group, an N-phenoxadiyl group, or an N-phenothiadiyl group is more preferable.

  Specific examples of X1 and X2 in this case include, for example, N-carbazoyl group, 2-methyl-N-carbazoyl group, 3-methyl-N-carbazoyl group, 4-methyl-N-carbazoyl group, 3-n- Butyl-N-carbazoyl group, 3-n-hexyl-N-carbazoyl group, 3-n-octyl-N-carbazoyl group, 3-n-decyl-N-carbazoyl group, 3,6-dimethyl-N-carbazoyl group 2-methoxy-N-carbazoyl group, 3-methoxy-N-carbazoyl group, 3-ethoxy-N-carbazoyl group, 3-isopropoxy-N-carbazoyl group, 3-n-butoxy-N-carbazoyl group, 3 -N-octyloxy-N-carbazoyl group, 3-n-decyloxy-N-carbazoyl group, 3-phenyl-N-carbazoyl group, 3- (4'-methyl) Eniru) -N- carbazoyl group, 3-chloro -N- carbazoyl group, N- phenoxazyl group, such as N- phenothiazyl group or 2-methyl -N- phenothiazyl group.

  Further, when X2 is —N (Y1) (Y2), Y1 and Y2 are arbitrary as long as they have an aromatic carbocyclic skeleton or an aromatic heterocyclic skeleton, and one or two or more in the skeleton Substituents may be introduced. Examples of the substituent to be introduced include a halogen atom, an alkyl group, an alkoxy group, and an aryl group. Y1 and Y2 preferably have a total carbon number of 6 to 20.

  Examples of the aromatic carbocyclic group of Y1 and Y2 include a phenyl group, a naphthyl group, and an anthryl group, and examples of the aromatic heterocyclic group include a furyl group, a thienyl group, and a pyridyl group. . Y1 and Y2 are unsubstituted or substituted with, for example, an aromatic carbocyclic group having 6 to 20 carbon atoms in total, or one or more halogen atoms, alkyl groups, alkoxy groups, or aryl groups, or total It is preferably an aromatic heterocyclic group having 3 to 20 carbon atoms. More preferably, the total number of carbon atoms in which one or two or more unsubstituted or halogen atoms, alkyl groups having 1 to 14 carbon atoms, alkoxy groups having 1 to 14 carbon atoms or aryl groups having 6 to 10 carbon atoms have been introduced. 6-20 aromatic carbocyclic groups. More preferably, the total number of carbon atoms in which one or two or more unsubstituted or halogen atoms, alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms have been introduced. 6 to 16 aromatic carbocyclic groups.

  Specific examples of such Y1 and Y2 include, for example, phenyl group, 1-naphthyl group, 2-naphthyl group, 2-anthryl group, 9-anthryl group, 4-quinolyl group, 4-pyridyl group, 3-pyridyl group. Group, 2-pyridyl group, 3-furyl group, 2-furyl group, 3-thienyl group, 2-thienyl group, 2-oxazolyl group, 2-thiazolyl group, 2-benzoxazolyl group, 2-benzothiazolyl group, 2-benzimidazolyl group, 4-methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 4-ethylphenyl group, 3-ethylphenyl group, 2-ethylphenyl group, 4-n-propylphenyl group, 4 -Isopropylphenyl group, 2-isopropylphenyl group, 4-n-butylphenyl group, 4-isobutylphenyl group, 4-sec-butylphenyl group, -Sec-butylphenyl group, 4-tert-butylphenyl group, 3-tert-butylphenyl group, 2-tert-butylphenyl group, 4-n-pentylphenyl group, 4-isopentylphenyl group, 2-neopentyl group Phenyl group, 4-tert-pentylphenyl group, 4-n-hexylphenyl group, 4- (2′-ethylbutyl) phenyl group, 4-n-heptylphenyl group, 4-n-octylphenyl group, 4- (2 '-Ethylhexyl) phenyl group, 4-tert-octylphenyl group, 4-n-decylphenyl group, 4-n-dodecylphenyl group, 4-n-tetradecylphenyl group, 4-cyclopentylphenyl group, 4-cyclohexylphenyl Group, 4- (4′-methylcyclohexyl) phenyl group, 4- (4′-tert-butylcyclo) Xyl) phenyl group, 3-cyclohexylphenyl group, 2-cyclohexylphenyl group, 4-ethyl-1-naphthyl group, 6-n-butyl-2-naphthyl group, 2,4-dimethylphenyl group, 2,5-dimethyl Phenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,6-dimethylphenyl group, 2,4-diethylphenyl group, 2,3,5-trimethylphenyl group, 2,3,6 -Trimethylphenyl group, 3,4,5-trimethylphenyl group, 2,6-diethylphenyl group, 2,5-diisopropylphenyl group, 2,6-diisobutylphenyl group, 2,4-di-tert-butylphenyl group 2,5-di-tert-butylphenyl group, 4,6-di-tert-butyl-2-methylphenyl group, 5-tert-butyl-2-methyl Ruphenyl group, 4-tert-butyl-2,6-dimethylphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 3-ethoxyphenyl group, 2-ethoxy Phenyl group, 4-n-propoxyphenyl group, 3-n-propoxyphenyl group, 4-isopropoxyphenyl group, 2-isopropoxyphenyl group, 4-n-butoxyphenyl group, 4-isobutoxyphenyl group, 2- sec-butoxyphenyl group, 4-n-pentyloxyphenyl group, 4-isopentyloxyphenyl group, 2-isopentyloxyphenyl group, 4-neopentyloxyphenyl group, 2-neopentyloxyphenyl group, 4-n -Hexyloxyphenyl group, 2- (2'-ethylbutyl) oxyphenyl group, 4 n-octyloxyphenyl group, 4-n-decyloxyphenyl group, 4-n-dodecyloxyphenyl group, 4-n-tetradecyloxyphenyl group, 4-cyclohexyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2 -Methoxy-1-naphthyl group, 4-methoxy-1-naphthyl group, 4-n-butoxy-1-naphthyl group, 5-ethoxy-1-naphthyl group, 6-methoxy-2-naphthyl group, 6-ethoxy- 2-naphthyl group, 6-n-butoxy-2-naphthyl group, 6-n-hexyloxy-2-naphthyl group, 7-methoxy-2-naphthyl group, 7-n-butoxy-2-naphthyl group, 2- Methyl-4-methoxyphenyl group, 2-methyl-5-methoxyphenyl group, 3-methyl-5-methoxyphenyl group, 3-ethyl-5-methoxyphenyl Group, 2-methoxy-4-methylphenyl group, 3-methoxy-4-methylphenyl group, 2,4-dimethoxyphenyl group, 2,5-dimethoxyphenyl group, 2,6-dimethoxyphenyl group, 3,4 -Dimethoxyphenyl group, 3,5-dimethoxyphenyl group, 3,5-diethoxyphenyl group, 3,5-di-n-butoxyphenyl group, 2-methoxy-4-ethoxyphenyl group, 2-methoxy-6- Ethoxyphenyl group, 3,4,5-trimethoxyphenyl group, 4-phenylphenyl group, 3-phenylphenyl group, 2-phenylphenyl group, 4- (4′-methylphenyl) phenyl group, 4- (3 ′ -Methylphenyl) phenyl group, 4- (4'-methoxyphenyl) phenyl group, 4- (4'-n-butoxyphenyl) phenyl group, 2- (2'-methoxy) Phenyl) phenyl group, 4- (4′-chlorophenyl) phenyl group, 3-methyl-4-phenylphenyl group, 3-methoxy-4-phenylphenyl group, 4-fluorophenyl group, 3-fluorophenyl group, 2- Fluorophenyl group, 4-chlorophenyl group, 3-chlorophenyl group, 2-chlorophenyl group, 4-bromophenyl group, 2-bromophenyl group, 4-chloro-1-naphthyl group, 4-chloro-2-naphthyl group, 6 -Bromo-2-naphthyl group, 2,3-difluorophenyl group, 2,4-difluorophenyl group, 2,5-difluorophenyl group, 2,6-difluorophenyl group, 3,4-difluorophenyl group, 3, 5-difluorophenyl group, 2,3-dichlorophenyl group, 2,4-dichlorophenyl group, 2,5-dichlorophenyl group, , 4-dichlorophenyl group, 3,5-dichlorophenyl group, 2,5-dibromophenyl group, 2,4,6-trichlorophenyl group, 2,4-dichloro-1-naphthyl group, 1,6-dichloro-2- Naphthyl group, 2-fluoro-4-methylphenyl group, 2-fluoro-5-methylphenyl group, 3-fluoro-2-methylphenyl group, 3-fluoro-4-methylphenyl group, 2-methyl-4-fluoro Phenyl group, 2-methyl-5-fluorophenyl group, 3-methyl-4-fluorophenyl group, 2-chloro-4-methylphenyl group, 2-chloro-5-methylphenyl group, 2-chloro-6-methyl Phenyl group, 2-methyl-3-chlorophenyl group, 2-methyl-4-chlorophenyl group, 3-methyl-4-chlorophenyl group, 2-chloro-4,6-dimethyl Ruphenyl group, 2-methoxy-4-fluorophenyl group, 2-fluoro-4-methoxyphenyl group, 2-fluoro-4-ethoxyphenyl group, 2-fluoro-6-methoxyphenyl group, 3-fluoro-4-ethoxy Examples thereof include a phenyl group, 3-chloro-4-methoxyphenyl group, 2-methoxy-5-chlorophenyl group, 3-methoxy-6-chlorophenyl group, and 5-chloro-2,4-dimethoxyphenyl group. Y1 and Y2 are not limited to these.

  R11 and R12 described in the formula (2) may be any groups as long as they are the above-described groups. However, a hydrogen atom, a linear, branched or cyclic alkyl group, an aromatic carbocyclic group having 6 to 20 carbon atoms in total, A C3-C20 aromatic heterocyclic group or aralkyl group is preferred. Even when R11 and R12 are an aromatic carbocyclic group, an aromatic heterocyclic group or an aralkyl group, they may be unsubstituted, or one or more substituents may be introduced. Examples of the substituent to be introduced include a halogen atom, an alkyl group, an alkoxy group, and an aryl group.

  R11 and R12 are a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 16 carbon atoms, a substituted or unsubstituted aryl group having 4 to 16 carbon atoms, or a substituted or unsubstituted group having 5 to 16 carbon atoms. The aralkyl group is preferably. More preferably, a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted aralkyl group having 7 to 12 carbon atoms. It is. Further, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, an aromatic carbocyclic group having 6 to 10 carbon atoms, or a carbocyclic aralkyl group having 7 to 10 carbon atoms is more preferable.

  Specific examples of the substituted or unsubstituted aryl group represented by R11 and R12 include, for example, the substituted or unsubstituted aryl groups exemplified as specific examples of Y1 and Y2. Specific examples of the linear, branched or cyclic alkyl group of Y1, Y2 include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert- Butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, 2-ethylbutyl group, 3,3-dimethylbutyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl Group, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-tetradecyl group or n-hexadecyl group, etc. Is not to be done.

  Specific examples of the substituted or unsubstituted aralkyl group of R11 and R12 include, for example, benzyl group, phenethyl group, α-methylbenzyl group, α, α-dimethylbenzyl group, 1-naphthylmethyl group, 2-naphthyl. Methyl group, furfuryl group, 2-methylbenzyl group, 3-methylbenzyl group, 4-methylbenzyl group, 4-ethylbenzyl group, 4-isopropylbenzyl group, 4-tert-butylbenzyl group, 4-n-hexylbenzyl Group, 4-nonylbenzyl group, 3,4-dimethylbenzyl group, 3-methoxybenzyl group, 4-methoxybenzyl group, 4-ethoxybenzyl group, 4-n-butoxybenzyl group, 4-n-hexyloxybenzyl group 4-nonyloxybenzyl group, 4-fluorobenzyl group, 3-fluorobenzyl group, 2-chlorobenzyl group Rui like 4-chlorobenzyl group, but is not limited thereto.

  R13 and R14 shown in the formula (2) may be any groups as long as they are the above-mentioned groups. It is preferably an aromatic carbocyclic group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 3 to 20 carbon atoms in total. When R13 and R14 are aromatic carbocyclic groups or aromatic heterocyclic groups, these may be unsubstituted, or one or more substituents may be introduced. Examples of the substituent to be introduced include a halogen atom, an alkyl group, an alkoxy group, and an aryl group.

  R13 and R14 include a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 16 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 16 carbon atoms, or a carbon number of 4 to 20 Of these, substituted or unsubstituted aryl groups are preferred. More preferably, a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 8 carbon atoms, or a substitution having 6 to 12 carbon atoms. Or it is an unsubstituted aryl group, More preferably, it is a hydrogen atom.

  Specific examples of the linear, branched or cyclic alkyl group of R13 and R14 include, for example, the linear, branched or cyclic alkyl groups mentioned as specific examples of R3 to R10 described in the formula (1). . Specific examples of the substituted or unsubstituted aryl group for R13 and R14 include, for example, the substituted or unsubstituted aryl groups listed as specific examples for Y1 and Y2.

  Specific examples of halogen atoms of R13 and R14, or linear, branched or cyclic alkoxy groups include, for example, halogen atoms such as fluorine atom, chlorine atom or bromine atom, methoxy group, ethoxy group, n-propoxy group, Isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, n-pentyloxy group, isopentyloxy group, neopentyloxy group, cyclopentyloxy group, n-hexyloxy group, 2-ethylbutoxy group, 3 , 3-dimethylbutoxy group, cyclohexyloxy group, n-heptyloxy group, cyclohexylmethyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group, n-dodecyloxy group, n-tetradecyloxy group or n-hexadecyl Alkoxy groups such as alkoxy groups.

  As a compound shown to Formula (2) demonstrated above, the compound represented by Formula (2-1)-Formula (2-5) is mentioned, for example. That is, 7- (N′-carbazolyl) -N, N-diphenyl-9,9-dimethyl-9H-fluoren-2-amine of formula (2-1), 7- (N ′ of formula (2-2) -Carbazolyl) -N, N-di (4-biphenylyl) -9,9-dimethyl-9H-fluoren-2-amine, 7- (N'-carbazolyl) -N, N-di of formula (2-3) (2-Naphtyl) -9,9-dimethyl-9H-fluoren-2-amine, 7- (N′-carbazolyl) -N, N-di (1-naphthyl) -9,9 of formula (2-4) -Dimethyl-9H-fluoren-2-amine, 7- (N'-carbazolyl) -N- (4-biphenylyl) -N- (2-naphthyl) -9,9-dimethyl-9H of formula (2-5) -Fluoren-2-amine.

  Examples of the compound represented by the formula (2) include the following compounds (2-6) to (2-105) in addition to the above. That is, (2-6) 7- (N′-carbazoyl) -N, N-diphenyl-9H-fluoren-2-amine, (2-7) 7- (N′-carbazoyl) -N-phenyl-N— (4′-methylphenyl) -9-methyl-9H-fluoren-2-amine, (2-8) 7- (N′-carbazoyl) -N, N-diphenyl-9,9-dimethyl-9H-fluorene- 2-amine, (2-9) 7- (N′-carbazoyl) -N-phenyl-N- (3′-methylphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-10 ) 7- (N′-carbazoyl) -N-phenyl-N- (4′-methylphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-11) 7- (N′-carbazoyl) ) -N-phenyl-N- (4′-ethylphenol) ) -9,9-dimethyl-9H-fluoren-2-amine, (2-12) 7- (N′-carbazoyl) -N-phenyl-N- (4′-tert-butylphenyl) -9,9 -Dimethyl-9H-fluoren-2-amine, (2-13) 7- (N'-carbazoyl) -N-phenyl-N- (3 ', 4'-dimethylphenyl) -9,9-dimethyl-9H- Fluoren-2-amine, (2-14) 7- (N′-carbazoyl) -N-phenyl-N- (3 ′, 5′-dimethylphenyl) -9,9-dimethyl-9H-fluoren-2-amine (2-15) 7- (N′-carbazoyl) -N, N-di (3′-methylphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-16) 7- ( N′-carbazoyl) -N, N-di (4′-methyl) Enyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-17) 7- (N′-carbazoyl) -N, N-di (4′-ethylphenyl) -9,9-dimethyl- 9H-fluoren-2-amine, (2-18) 7- (N′-carbazoyl) -N-phenyl-N- (3′-methoxyphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-19) 7- (N′-carbazoyl) -N-phenyl-N- (4′-methoxyphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-20) 7- ( N'-carbazoyl) -N-phenyl-N- (4'-ethoxyphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-21) 7- (N'-carbazoyl) -N- Phenyl-N- (4′-n-butoxyphe Nyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-22) 7- (N′-carbazoyl) -N, N-di (4′-methoxyphenyl) -9,9-dimethyl- 9H-fluoren-2-amine, (2-23) 7- (N'-carbazoyl) -N- (3'-methylphenyl) -N- (4 "-methoxyphenyl) -9,9-dimethyl-9H- Fluoren-2-amine, (2-24) 7- (N′-carbazoyl) -N- (4′-methylphenyl) -N- (4 ″ -methoxyphenyl) -9,9-dimethyl-9H-fluorene- 2-amine or (2-25) 7- (N′-carbazoyl) -N-phenyl-N- (3′-fluorophenyl) -9,9-dimethyl-9H-fluoren-2-amine.

  (2-26) 7- (N'-carbazoyl) -N-phenyl-N- (4'-chlorophenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-27) 7- (N′-carbazoyl) -N-phenyl-N- (4′-phenylphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-28) 7- (N′-carbazoyl) -N -Phenyl-N- (1'-naphthyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-29) 7- (N'-carbazoyl) -N-phenyl-N- (2'- Naphthyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-30) 7- (N'-carbazoyl) -N- (4'-methylphenyl) -N- (2 "-naphthyl)- 9,9-dimethyl-9H-fluoren-2-amine, 2-31) 7- (N′-carbazoyl) -N-phenyl-N- (2′-furyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-32) 7- (N ′ -Carbazoyl) -N-phenyl-N- (2'-thienyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-33) 7- (N'-carbazoyl) -N, N-diphenyl -4-fluoro-9,9-dimethyl-9H-fluoren-2-amine, (2-34) 7- (N'-carbazoyl) -N, N-diphenyl-3-methoxy-9,9-dimethyl-9H -Fluoren-2-amine, (2-35) 7- (N'-carbazoyl) -N, N-diphenyl-4-phenyl-9,9-dimethyl-9H-fluoren-2-amine, (2-36) 7- (3′-Methyl-N′-carbazoyl -N, N-diphenyl-9,9-dimethyl-9H-fluoren-2-amine, (2-37) 7- (3'-methoxy-N'-carbazoyl) -N, N-diphenyl-9,9- Dimethyl-9H-fluoren-2-amine, (2-38) 7- (3′-chloro-N′-carbazoyl) -N, N-diphenyl-9,9-dimethyl-9H-fluoren-2-amine, 2-39) 2,7-di (N′-carbazoyl) -9,9-dimethyl-9H-fluorene, (2-40) 7- (N′-phenoxadiyl) -N, N-diphenyl-9, 9-Dimethyl-9H-fluoren-2-amine, (2-41) 7- (N′-phenoxadiyl) -N, N-di (4′-methylphenyl) -9,9-dimethyl-9H-fluorene -2-amine, (2-42) 7- (N′-Fe Noxadiyl) -9,9-dimethyl-9H-fluorene, (2-43) 7- (N′-phenothiadiyl) -N, N-diphenyl-9,9-dimethyl-9H-fluoren-2-amine, (2- 44) 7- (N′-phenothiadiyl) -N-phenyl-N- (3′-methylphenyl) -9,9-dimethyl-9H-fluoren-2-amine, or (2-45) 7- (N ′ -Phenothiadiyl) -N-phenyl-N- (4'-methylphenyl) -9,9-dimethyl-9H-fluoren-2-amine.

  (2-46) 7- (N′-phenothiadiyl) -N, N-di (4′-methylphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-47) 7- (N′-phenothiadiyl) -N-phenyl-N- (4′-methoxyphenyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-48) 7- (N′-phenothiadiyl) -N -Phenyl-N- (2'-naphthyl) -9,9-dimethyl-9H-fluoren-2-amine, (2-49) 2,7-di (N-phenothiadiyl) -9,9-dimethyl-9H- Fluorene, (2-50) 7- (N′-carbazoyl) -N, N-diphenyl-9,9-diethyl-9H-fluoren-2-amine, (2-51) 7- (N′-carbazoyl)- N-phenyl-N- (4′-methyl Enyl) -9,9-diethyl-9H-fluoren-2-amine, (2-52) 7- (N′-carbazoyl) -N, N-di (4′-methylphenyl) -9,9-diethyl- 9H-fluoren-2-amine, (2-53) 7- (N′-carbazoyl) -N-phenyl-N- (3′-methoxyphenyl) -9,9-diethyl-9H-fluoren-2-amine, (2-54) 7- (N′-carbazoyl) -N, N-diphenyl-4-methyl-9,9-diethyl-9H-fluoren-2-amine, (2-55) 7- (N′-carbazoyl) ) -N, N-diphenyl-9-isopropyl-9H-fluoren-2-amine, (2-56) 7- (N'-carbazoyl) -N, N-diphenyl-9,9-di-n-propyl- 9H-fluoren-2-amine, (2 57) 7- (N′-carbazoyl) -N-phenyl-N- (4′-methylphenyl) -9,9-di-n-propyl-9H-fluoren-2-amine, (2-58) 7- (N′-carbazoyl) -N-phenyl-N- (4′-methoxyphenyl) -9,9-di-n-propyl-9H-fluoren-2-amine, (2-59) 2,7-di ( N-carbazoyl) -9,9-di-n-propyl-9H-fluorene, (2-60) 2,7-di (N-phenoxadiyl) -9,9-di-n-propyl-9H-fluorene (2-61) 7- (N'-carbazoyl) -N, N-diphenyl-9,9-di-n-butyl-9H-fluoren-2-amine, (2-62) 7- (N'- Carbazoyl) -N, N-di (4′-methylphenyl) -9,9-di-n-buty -9H-fluoren-2-amine, (2-63) 2,7-di (N-carbazoyl) -9,9-di-n-butyl-9H-fluorene, (2-64) 7- (N ' -Carbazoyl) -N-phenyl-N- (4'-methoxyphenyl) -9,9-di-n-pentyl-9H-fluoren-2-amine or (2-65) 7- (N-phenoxadiyl) ) -N-phenyl-N- (3'-methoxyphenyl) -9,9-di-n-pentyl-9H-fluoren-2-amine.

  (2-66) 7- (N′-carbazoyl) -N, N-di (4 ″ -methoxyphenyl) -9,9-di-n-pentyl-9H-fluoren-2-amine, 67) 2,7-di (N′-carbazoyl) -9,9-di-n-pentyl-9H-fluoren-2-amine, (2-68) 7- (N′-carbazoyl) -N, N— Diphenyl-9,9-di-n-hexyl-9H-fluoren-2-amine, (2-69) 7- (N′-carbazoyl) -N, N-di (4′-methylphenyl) -9,9 -Di-n-hexyl-9H-fluoren-2-amine, (2-70) 7- (N'-carbazoyl) -N, N-diphenyl-9-cyclohexyl-9H-fluoren-2-amine, (2- 71) 7- (N′-carbazoyl) -N, N-diphenyl-9,9 Di-n-octyl-9H-fluoren-2-amine, (2-72) 7- (N′-phenoxadiyl) -N, N-di (4′-methylphenyl) -9,9-di-n -Octyl-9H-fluoren-2-amine, (2-73) 7- (N'-carbazoyl) -N, N-diphenyl-9-methyl-9-ethyl-9H-fluoren-2-amine, (2- 74) 7- (N′-carbazoyl) -N, N-diphenyl-9-methyl-9-n-propyl-9H-fluoren-2-amine, (2-75) 7- (N′-phenothiadiyl) -N , N-diphenyl-9-methyl-9-n-propyl-9H-fluoren-2-amine, (2-76) 7- (N′-carbazoyl) -N, N-diphenyl-9-ethyl-9-n -Hexyl-9H-fluoren-2-amine, ( -77) 7- (N'-carbazoyl) -N, N-diphenyl-9-ethyl-9-cyclohexyl-9H-fluoren-2-amine, (2-78) 7- (N'-carbazoyl) -N, N-diphenyl-9-benzyl-9H-fluoren-2-amine, (2-79) 7- (N′-carbazoyl) -N, N-diphenyl-9,9-dibenzyl-9H-fluoren-2-amine, (2-80) 7- (N′-carbazoyl) -N, N-diphenyl-9,9-di (4′-methylbenzyl) -9H-fluoren-2-amine, (2-81) 7- (N '-Carbazoyl) -N, N-diphenyl-9,9-di (4'-methoxybenzyl) -9H-fluoren-2-amine, (2-82) 7- (N'-carbazoyl) -N-phenyl- N- (4′-methylphenyl) ) -9,9-dibenzyl-9H-fluoren-2-amine, (2-83) 7- (N′-carbazoyl) -N, N-di (4′-methylphenyl) -9,9-dibenzyl-9H -Fluoren-2-amine, (2-84) 7- (N'-carbazoyl) -N-phenyl-N- (4'-methoxyphenyl) -9,9-dibenzyl-9H-fluoren-2-amine, or (2-85) 7- (N'-carbazoyl) -N-phenyl-N- (4'-phenylphenyl) -9,9-dibenzyl-9H-fluoren-2-amine.

  Further, (2-86) 7- (N′-carbazoyl) -N-phenyl-N- (2′-naphthyl) -9,9-dibenzyl-9H-fluoren-2-amine, (2-87) 7- (N′-phenoxadiyl) -N-phenyl-N- (4′-methylphenyl) -9,9-dibenzyl-9H-fluoren-2-amine, (2-88) 7- (N′-phenothiadiyl) -N, N-di (4'-methylphenyl) -9,9-dibenzyl-9H-fluoren-2-amine, (2-89) 2,7- (N'-carbazoyl) -9,9-dibenzyl- 9H-fluorene, (2-90) 2,7- (N′-carbazoyl) -9,9-di (4′-methylbenzyl) -9H-fluorene, (2-91) 2- (N′-carbazoyl) -7- (N'-phenothiadiyl) -9,9-di 9-H-fluorene, (2-92) 7- (N′-carbazoyl) -N, N-diphenyl-9-methyl-9-benzyl-9H-fluoren-2-amine, (2-93) 7- ( N′-phenoxadiyl) -N, N-diphenyl-9-ethyl-9-benzyl-9H-fluoren-2-amine, (2-94) 7- (N′-carbazoyl) -N, N-diphenyl- 9,9-diphenyl-9H-fluoren-2-amine, (2-95) 7- (N′-carbazoyl) -N-phenyl-N- (4′-methylphenyl) -9,9-diphenyl-9H— Fluoren-2-amine, (2-96) 7- (N′-carbazoyl) -N, N-di (4′-methylphenyl) -9,9-diphenyl-9H-fluoren-2-amine, (2- 97) 7- (N′-carbazo ) -N-phenyl-N- (3′-methylphenyl) -9,9-di (4 ″ -methylphenyl) -9H-fluoren-2-amine, (2-98) 7- (N′-carbazoyl) ) -N-phenyl-N- (3'-methylphenyl) -9,9-di (4 "-methoxyphenyl) -9H-fluoren-2-amine, (2-99) 7- (N'-phenoxadi) Yl) -N, N-di (4′-methylphenyl) -9,9-diphenyl-9H-fluoren-2-amine, (2-100) 7- (N′-phenothiadiyl) -N, N-diphenyl- 9,9-diphenyl-9H-fluoren-2-amine, (2-101) 2,7-di (N′-carbazoyl) -9,9-di (4′-methylphenyl) -9H-fluorene, (2 -102) 2- (N-carbazoyl) -7- (N ' -Phenoxadiyl) -9,9-diphenyl-9H-fluorene, (2-103) 2- (N-phenoxadiyl) -7- (N'-phenothiadiyl) -9,9-diphenyl-9H-fluorene, (2-104) 7- (N′-carbazoyl) -N-phenyl-N- (4′-methylphenyl) -9-methyl-9-phenyl-9H-fluoren-2-amine, or (2-105) 7- (N′-carbazoyl) -N, N-diphenyl-9-ethyl-9-phenyl-9H-fluoren-2-amine.

  When an electric field is applied between the anode 11 and the cathode 31, the light emitting layer 23 generates light by recombination of holes injected from the anode 11 side and electrons injected from the cathode 31 side. It is an area to do. Examples of the material constituting the light emitting layer 23 include a light emitting function (a function of providing a recombination field between holes and electrons and connecting the recombination to light emission), and a charge injection function and a charge transport function. Those having the following are preferred. Thereby, while light emission efficiency improves, it becomes possible to emit light without providing an electron transport layer 24 described later. The charge injection function here refers to a function that can inject holes from the hole transport layer 22 and electrons from the cathode 31 when an electric field is applied. The charge transport function is a function of moving injected holes and electrons by the force of an electric field. That is, the light emitting layer 23 may have an electron transporting property and also has an electron transporting layer.

  In the light emitting layer 23, for example, a compound serving as a host (host material) is doped with a light emitting dye (luminescent guest material) of each color (blue, green, red), and when an electric field is applied, Each color is emitted according to the color tone of the luminescent pigment.

  Examples of the host material include naphthalene derivatives, indene derivatives, phenanthrene derivatives, pyrene derivatives, naphthacene derivatives, triphenylene derivatives, anthracene derivatives, perylene derivatives, picene derivatives, fluoranthene derivatives, acephenanthrylene derivatives, pentaphen derivatives, pentacene derivatives, Examples thereof include coronene derivatives, butadiene derivatives, stilbene derivatives, tris (8-quinolinolato) aluminum complexes, and bis (benzoquinolinolato) beryllium complexes. Specific examples include 9,10-di (2-naphthyl) anthracene (ADN) represented by the formula (8).

  As the light-emitting guest material, a material having high light emission efficiency, for example, an organic light-emitting material such as a low-molecular fluorescent dye, a fluorescent polymer, or a metal complex is used. Hereinafter, the light-emitting guest material of each color will be described.

  The blue light-emitting guest material is a compound having a peak in the light emission wavelength range of about 400 nm to 490 nm. As such an organic compound, naphthalene derivatives, anthracene derivatives, naphthacene derivatives, styrylamine derivatives or And bis (azinyl) methene boron complex. Specific examples include aminonaphthalene derivatives, aminoanthracene derivatives, aminochrysene derivatives, aminopyrene derivatives, styrylamine derivatives, and bis (azinyl) methene boron complexes, and one or more of these are preferably used.

  The green light-emitting guest material is a compound having a peak in the light emission wavelength range of about 490 nm to 580 nm. Examples of such organic compounds include naphthalene derivatives, anthracene derivatives, pyrene derivatives, naphthacene derivatives, fluoranthene. Derivatives, perylene derivatives, coumarin derivatives, quinacridone derivatives, indeno [1,2,3-cd] perylene derivatives, bis (azinyl) methene boron complex pyran dyes, and the like. Specific examples include aminoanthracene derivatives, fluoranthene derivatives, coumarin derivatives, quinacridone derivatives, indeno [1,2,3-cd] perylene derivatives, and bis (azinyl) methene boron complexes, one or two of these. More than species are preferably used.

  The red light-emitting guest material is a compound having a peak in the light emission wavelength range of about 580 nm to 700 nm. Examples of such an organic compound include Neil Red and DCM1 ({4-Dicyanmethyl-2- pyran derivatives such as methyl-6 (p-dimethylaminostyryl) -4H-pyran}) or DCJT ({4- (dicyanomethylene) -2-tert-butyl-6- (julolidylstyryl) -pyran}) and squarylium derivatives And porphyrin derivatives, chlorin derivatives, eurodiline derivatives, and the like, and one or more of these are preferably used.

  In addition, the light emitting layer 23 may be made to emit light of one color among them using the above-described light emitting guest material of each color, or a light emitting layer 23 that emits light of one color of each color is laminated. The light may be white. That is, the light emitting layer 23 may be any one of a blue light emitting layer, a green light emitting layer, and a red light emitting layer, or may be laminated to form a white light emitting layer.

  The electron transport layer 24 is for efficiently transporting electrons injected from the cathode 31 to the light emitting layer 23. Examples of the material constituting the electron transport layer 24 include quinoline, perylene, phenanthroline, bisstyryl, pyrazine, triazole, oxazole, oxadiazole, fluorenone, and derivatives and metal complexes thereof. Specific examples include tris (8-hydroxyquinoline) aluminum (abbreviated as Alq3) represented by the formula (9), and anthracene, naphthalene, phenanthrene, pyrene, anthracene, perylene, butadiene, coumarin, acridine, stilbene. Alternatively, 1,10-phenanthroline or a derivative or metal complex thereof can be used. These may be used alone or in combination of two or more.

  The cathode 31 is one electrode for applying an electric field to the light emitting layer 23 and is made of a light transmissive material. Thereby, the light emitted from the light emitting layer 23 and the light reflected from the surface of the anode 11 are extracted from the cathode 31 to the outside. In the cathode 31, a layer using a material having a small work function is formed on the light emitting layer 23 side, and a first cathode layer 31A and a second cathode layer 31B are laminated in order from the light emitting layer 23 side.

The first cathode layer 31 </ b> A is made of a material that has good light transmittance, a small work function, and can efficiently inject electrons into the electron transport layer 24. Examples of such materials include alkali metal oxides such as Li ₂ O, Cs ₂ O, LiF, and CaF ₂ , alkali metal fluorides, alkaline earth metal oxides, and alkaline earth fluorides.

  The second cathode layer 31B is made of a material having light transmissivity such as a thin-film MgAg electrode material or a Ca electrode material and having good conductivity. Further, in the case where the organic electroluminescent element is provided with a cavity structure in which emitted light is resonated and extracted particularly between the anode 11 and the cathode 31, the second cathode layer 31B includes, for example, Mg—Ag (9: 1). ) A semi-transmissive reflective material such as 10 nm thick may be used.

  The cathode 31 may have a structure in which a third cathode layer (not shown) is stacked on the second cathode layer 31B as a sealing electrode for suppressing electrode deterioration, if necessary.

  Examples of a method for forming each layer of the cathode 31 (the first cathode layer 31A, the second cathode layer 31B, and the third cathode layer as necessary) include a vacuum deposition method, a sputtering method, a plasma CVD method, and the like.

  Such an organic electroluminescent element can be manufactured as follows, for example.

  First, the anode 11 is formed on the substrate 10 by vapor deposition or sputtering. Subsequently, the organic layer 20 is formed on the anode 11. In this case, first, a first hole injection layer 21A containing an aniline derivative and an organic acid is formed on the anode 11 by a wet method such as a spin coating method. After that, the second hole injection layer 21B containing a thiophene derivative and an organic acid is formed by a wet method such as a spin coating method to form the hole injection layer 21. Subsequently, on the second hole injection layer 21B, a hole transport layer 22 containing at least one of the compounds represented by the formulas (1) and (2) by a vapor phase method such as a vacuum deposition method, The light emitting layer 23 and the electron transport layer 24 are laminated in this order. Thereby, the organic layer 20 is formed. Finally, the first cathode layer 31A and the second cathode layer 31B are laminated in this order on the electron transport layer 24 by vapor deposition or the like to form the cathode 31. Thereby, the organic electroluminescent element shown in FIG. 1 is completed. Here, in the organic layer 20, the hole transport layer 22, the light emitting layer 23, and the electron transport layer 24 are formed by a vapor phase method such as a vacuum deposition method, but may be formed by a wet method. As a result, as described above, the occurrence of a short circuit due to mixing of foreign substances is further suppressed, and the yield and the like are improved.

  In the organic electroluminescent element in the present embodiment, when a voltage is applied between the anode 11 and the cathode 31 and an electric field is applied to the organic layer 20, holes from the anode 11 are converted into the first hole injection layer 21A and the first hole injection layer 21A. The two-hole injection layer 21 </ b> B is efficiently injected into the hole transport layer 22. The hole transport layer 22 efficiently transports the injected holes to the light emitting layer. On the other hand, electrons from the cathode 31 are efficiently transported to the light emitting layer 23 via the electron transport layer 24. Thus, the holes that have moved from the anode 11 side and the electrons that have moved from the cathode 31 side recombine in the light emitting layer 23 to emit light. The light emitted from the light emitting layer 23 and the light reflected by the surface of the anode 11 are transmitted through the cathode 31 and emitted. In this case, if free protons are contained in the second hole transport layer 21B, the protons move together with the holes. Here, if the hole transport layer 22 does not contain the compounds represented by the above formulas (1) and (2), protons diffuse into the light emitting layer 23, the luminous efficiency is lowered, and sufficient luminous intensity is maintained. It becomes difficult to do. However, since the hole transport layer 22 contains at least one of the compounds represented by the formulas (1) and (2), the hole transport layer 22 captures the protons and the hole injection layer. The holes injected by 21 can be efficiently transported to the light emitting layer 23. For this reason, even if it drives for a long time, the fall of luminous efficiency is suppressed.

  That is, in this organic electroluminescent element, the organic layer 20 has a second hole injection layer 21B and a hole transport layer 22 stacked in this order from the anode 11 side between the anode 11 and the light emitting layer 23. is doing. In this case, the second hole injection layer 21B includes a thiophene derivative and an organic acid, and the hole transport layer 22 includes at least one of the compounds represented by Formula (1) and Formula (2). Thereby, since the high light emission intensity is maintained satisfactorily, the life characteristics can be improved. In this case, the first hole injection layer 21A containing an aniline derivative and an organic acid is provided between the anode 11 and the second hole injection layer 21B. Thereby, even if the material used when forming the 2nd hole injection layer 21B shows strong acidity, the corrosion by the acid of the anode 11 is suppressed and a high lifetime characteristic can be acquired.

  If the anode 11 contains an alloy containing aluminum, the alloy containing aluminum contains aluminum as a main component and an element having a work function relatively lower than that of aluminum as a subcomponent, the anode 11 becomes high. Thereby, even if the light emission intensity of the light emitting layer 23 is low, the light quantity which permeate | transmits the cathode 31 is securable. Therefore, since the driving voltage can be kept low, the life characteristics can be further improved.

  Next, application examples of the above-described organic electroluminescence device will be described. Here, taking a display device as an example, the above-described organic electroluminescent element is used as follows.

[2. Display device]
FIG. 2 shows a cross-sectional configuration of the display device. This display device is configured to have an insulating layer 12 and organic electroluminescent elements 1R, 1G, and 1B on a substrate 10 provided with a drive circuit (not shown) such as a TFT. In this display device, a protective layer 32 is formed on the organic electroluminescent elements 1R, 1G, and 1B so as to cover them, and is sealed by an adhesive layer 33 provided on the protective layer 32. The entire surface is sealed by the substrate 40 for use. That is, the driving method of the display device described here is an active matrix method.

  The substrate 10 is formed on a transparent substrate such as glass, a silicon substrate, a film-like flexible substrate, or the like, and a driving circuit (not shown) such as a TFT and planarization insulation for each of the organic electroluminescent elements 1R, 1G, and 1B. A membrane (not shown) is provided.

  The organic electroluminescent elements 1R, 1G, and 1B have the same configuration as the organic electroluminescent element described above. Here, it is assumed that light extracted from the organic electroluminescent elements 1R, 1G, and 1B exhibits red, green, and blue, respectively, in the display device. Here, since the sealing substrate 40 described later has a color filter (not shown), the light emitting layer 23 included in the organic electroluminescent elements 1R, 1G, and 1B has the same configuration. However, they may have different configurations. In that case, in the organic electroluminescent elements 1R, 1G, and 1B, the luminescent guest materials included in the respective light emitting layers 23 are different.

  The insulating layer 12 is for ensuring insulation between the anode 11 and the cathode 31 of the organic electroluminescent elements 1R, 1G, and 1B and accurately forming the light emitting region in a desired shape. The insulating layer 12 is provided on the substrate 10 so as to surround each anode 11 and form an opening between each anode 11 of the organic electroluminescent elements 1R, 1G, and 1B. Such an insulating layer 12 is made of, for example, a photosensitive resin such as polyimide. Here, the organic layer 20 and the cathode 31 are also provided continuously on the insulating layer 12, but emission light is generated only in the opening of the insulating layer 12 (upper portion of the anode 11). .

The protective layer 32 is for preventing moisture and the like from entering the organic layer 20 and is made of a material having low permeability and water absorption and has a sufficient thickness. Further, the protective layer 32 is made of a material having a high transmittance with respect to the light generated in the light emitting layer 23 and having a transmittance of 80% or more, for example. For example, the protective layer 32 has a thickness of about 2 μm to 3 μm and is made of an amorphous insulating material. Specifically, amorphous silicon (α-Si), amorphous silicon carbide (α-SiC), amorphous silicon nitride (α-Si _1-x N _x ), or amorphous carbon (α-C) is preferable. Since these amorphous insulating materials do not constitute grains, the water permeability is low and a good protective layer 32 is obtained. The protective layer 32 may be made of a transparent conductive material such as ITO.

  The adhesive layer 33 is made of, for example, a thermosetting resin or an ultraviolet curable resin.

  The sealing substrate 40 is positioned on the cathode 31 side of the organic electroluminescent elements 1R, 1G, and 1B, and seals the organic electroluminescent elements 1R, 1G, and 1B together with the adhesive layer 32. The sealing substrate 40 is made of a material such as glass that can transmit light generated by the organic electroluminescent elements 1R, 1G, and 1B. The sealing substrate 40 is provided with a color filter (not shown), for example. As a result, the light generated in the organic electroluminescent elements 1R, 1G, and 1B is taken out, and the external light reflected by the organic electroluminescent elements 1R, 1G, and 1B and the wiring (not shown) therebetween is absorbed, and the contrast is increased. You may come to improve.

  The color filter may be provided on either side of the sealing substrate 40, but is preferably provided on the organic electroluminescent element 1R, 1G, 1B side. This is because the color filter is not exposed on the surface and can be protected by the adhesive layer 33. In addition, since the distance between the light emitting layer 23 and the color filter is narrowed, light emitted from the organic electroluminescent elements 1R, 1B, and 1G is incident on the adjacent color filters of other colors, thereby causing color mixing. It is because it can avoid. The color filter includes a red filter, a green filter, and a blue filter (all not shown), and is sequentially arranged corresponding to the organic electroluminescent elements 1R, 1G, and 1B. Each of the red filter, the green filter, and the blue filter is, for example, rectangular and has no gap. These red filter, green filter, and blue filter may each be made of a resin mixed with a pigment. By selecting this pigment, the light transmittance is adjusted to be high in the target red, green or blue wavelength range, and low in other wavelength ranges.

  This display device can be manufactured, for example, as follows.

  First, a substrate 10 is prepared, and an anode 11 is formed thereon by, for example, sputtering, and is formed into a predetermined shape by, for example, dry etching.

  Subsequently, a photosensitive resin is applied over the entire surface of the substrate 10 so as to cover the anode 11, and an insulating layer 12 is formed by providing an opening corresponding to the light emitting region by photolithography, for example, and baking.

  After that, for example, after the organic layer 20 is formed by the same procedure as that for manufacturing the organic electroluminescent element described above, the cathode 31 is formed on the organic layer 20. In this way, organic electroluminescent elements 1R, 1G, and 1B are formed.

  After forming the organic electroluminescent elements 1R, 1G, and 1B, a protective film 32 is formed thereon. As a method for forming the protective film 32, a film forming method in which the energy of the film forming particles is small, such as a vapor deposition method or a CVD method, is preferable to the extent that the protective film 32 is not affected. The protective film 32 is preferably formed continuously with the formation of the cathode 31 without exposing the cathode 31 to the atmosphere. It is because it can suppress that the organic layer 20 deteriorates with the water | moisture content or oxygen in air | atmosphere. Further, in order to prevent a decrease in luminance due to deterioration of the organic layer 20, the film forming temperature of the protective film 32 is set to room temperature, and in order to prevent the protective film 32 from being peeled off, the film stress is minimized. It is desirable to film.

  Further, for example, a red filter material is formed on the sealing substrate 40 by applying a red filter material by spin coating or the like, and patterning and baking by a photolithography technique. Subsequently, similarly to the red filter, a blue filter and a green filter are sequentially formed.

  After that, an adhesive layer 33 is formed on the protective film 32, and the sealing substrate 40 is bonded through the adhesive layer 33. In that case, it is preferable to arrange | position the surface which formed the color filter of the board | substrate 40 for sealing on the organic electroluminescent element 1R, 1G, 1B side. Thus, the display device shown in FIG. 2 is completed.

  In such a display device, when a drive voltage is applied between the anode 11 and the cathode 31 in each of the organic electroluminescent elements 1R, 1G, and 1B selected based on the image data, an electric field is applied to the organic layer 20. . In the organic layer 20 to which this electric field is applied, holes and electrons are recombined in the light emitting layer 23 to generate emitted light. The emitted light passes through the color filter and the sealing substrate 40 and is extracted.

  According to this display device, the organic layer 20 of the organic electroluminescent elements 1R, 1B, and 1G is disposed between the anode 11 and the light emitting layer 23 in order from the anode 11 side in order from the second hole transport layer 21B and the positive layer. It has a hole transport layer 22. Thereby, since the high light emission intensity is maintained satisfactorily, the life characteristics can be improved. Other functions and effects are the same as those of the organic electroluminescent element described above.

[3. Modified example]
In the organic electroluminescence device of the present embodiment, the first hole injection layer 21A containing an aniline derivative and an organic acid is provided in the hole transport layer 21, but the present invention is not limited to this. For example, the second hole injection layer 21B containing a thiophene derivative and an organic acid may be provided without providing the first hole injection layer 21A. That is, the hole injection layer 21 may be configured by a layer (first layer) containing a thiophene derivative and an organic acid. Even in this case, the same effects as those of the organic electroluminescent element having the first hole injection layer 21A can be obtained. In this case, if the material used when forming the layer containing the thiophene derivative and the organic acid shows strong acidity, it becomes susceptible to corrosion when the anode 11 contains an aluminum alloy. For this reason, it is preferable that a layer made of a material having acid resistance such as ITO, IZO, MoO ₃ or V ₂ O ₅ is formed on the organic layer 20 side of the anode 11. Thereby, it becomes difficult to receive the influence of the corrosion which may arise when the anode 11 forms the layer containing a thiophene derivative and an organic acid. Therefore, higher life characteristics can be obtained.

  In the above-described embodiment and modification, the organic layer 20 is configured by the hole injection layer 21, the hole transport layer 22, the light emitting layer 23, and the electron transport layer 24, but is not limited thereto. That is, the organic layer 20 includes a layer containing a thiophene derivative and an organic acid between the light emitting layer 23 and the anode 11, and a layer containing at least one of the compounds represented by the formulas (1) and (2). Any other layer may be provided as necessary. The same applies to the configurations of the anode 11 and the cathode 31.

  Furthermore, in the above-described embodiment and modification, the first hole injection layer 21A, the second hole injection layer 21B, the hole transport layer 22, the light emitting layer 23, and the electron transport layer 24 that constitute the organic layer 20 are respectively formed. Although the case of forming with a single layer has been mainly described, each layer may be formed with a plurality of layers. Even in this case, the same effect can be obtained.

  Furthermore, in the above-described embodiments and modifications, the organic electroluminescent element including the single organic layer 20 has been described. However, the organic layer 20 may be stacked to form a so-called stack type. This stack type is also called a multi-photo emission element (MPE element), and is described in, for example, Japanese Patent Application Laid-Open No. 2003-272860. As described above, even when the plurality of organic layers 20 are stacked via the insulating charge generation layer, the same effect can be obtained.

  Examples of the present invention will be described in detail.

(Experimental Examples 1 to 11)
The organic electroluminescent element shown in FIG. 1 was produced by the following procedure.

  First, an anode 11 was formed on a substrate 10 made of 30 mm × 30 mm glass. In this case, an aluminum alloy layer (AlNd layer; thickness 150 nm) containing 10% by weight of neodymium (Nd), which is a lanthanoid element, was deposited.

Next, an insulating layer made of silicon oxide (SiO ₂ ) was formed on the anode 11 by RF sputtering so as to have an opening of 2 mm × 2 mm serving as a light emitting region. After that, pretreatment was performed with oxygen plasma.

  Next, the organic layer 20 was formed on the anode 11. First, a first hole injection layer 21A having a thickness of 20 nm was formed on the anode 11. In this case, using a solution containing the polymer compound represented by the formula (7-1) as the aniline derivative and the compound represented by the formula (4-1) as the organic acid, the spin coating method (3000 rpm) is performed in an air atmosphere. , 120 seconds) to form a coating film. This solution was prepared by mixing a material obtained by mixing the polymer compound represented by formula (7-1) and the compound represented by formula (4-1) at a weight ratio of 8: 2, and having a solid content concentration of 3 with respect to the solvent. It was dissolved and adjusted so that it might become weight%. As the solvent, a mixture of N-methyl-2-pyrrolidine and phenol at a weight ratio of 5: 2 was used. Thereafter, the coating film was heated at 200 ° C. for 30 minutes in a heating furnace in an air atmosphere and dried. In addition, when the molecular weight of the polymer compound represented by the formula (7-1) used here was measured by gel permeation chromatography (GPC method), l + m + n in the formula (7-1) was 20 or less.

  Subsequently, a second hole injection layer 21B having a thickness of 15 nm was formed on the first hole injection layer 21A. In this case, the polymer compound (q = 2000) shown in Formula (3-1) as the thiophene derivative, the organic acid shown in Formula (5) and the organic acid shown in Formula (6) as the organic acid. A coating film was formed by spin coating (6000 rpm, 120 seconds) in an air atmosphere using a solution containing (p = 1000). This solution is a material in which the polymer compound represented by formula (3-1), the organic acid represented by formula (5), and the organic acid represented by formula (6) are mixed at a weight ratio of 1: 2: 8. Was dissolved so as to have a solid content concentration of 1% by weight with respect to the solvent. As this solvent, a mixture of water and ethanol in a weight ratio of 2: 1 was used. Thereafter, the coating film was heated at 200 ° C. for 30 minutes in a heating furnace in an air atmosphere and dried. The above q and p are also calculated from the results obtained by measuring the molecular weight of each polymer compound by the GPC method.

  Subsequently, a 10 nm-thick hole transport layer 22 was formed on the second hole injection layer 21B by a vapor deposition method. At this time, the deposition rate was 1 nm / second. In this case, as the material for forming the hole transport layer 22, as shown in Table 1, the compounds represented by the formula (1) are the compounds represented by the formula (1-3), the formula (1-9), and the formula A compound represented by (1-10), formula (1-15), formula (1-18) or formula (1-19) (Experimental Examples 1 to 6) or a compound represented by formula (2) ( The compounds shown in (2-1) to (2-5) (Experimental Examples 7 to 11) were used.

  Subsequently, a light emitting layer 23 having a film thickness of 28 nm was formed on the hole transport layer 22 by vapor deposition. In this case, the compound (9,10-di (2-naphthyl) anthracene; ADN) represented by the formula (8) is used as the host material, and BD-142 manufactured by Idemitsu Kosan Co., Ltd. is used as the blue light-emitting guest material. Doped. The vapor deposition rates were 1 nm / second (host material) and 0.05 nm / second (luminescent guest material), respectively, and the doping amount of the luminescent guest material was 5% by volume.

  Subsequently, an electron transport layer 24 having a thickness of 12 nm was formed on the light emitting layer 23 by vapor deposition. In this case, Alq3 represented by the formula (9) was deposited at a deposition rate of 1 nm / second. Thereby, the organic layer 20 was formed.

  Next, the cathode 31 having the first cathode layer 31A and the second cathode layer 31B was formed on the organic layer 20 by a vacuum evaporation method. In this case, a first cathode layer 31A made of LiF having a thickness of about 0.3 nm is formed at a deposition rate of 0.01 nm / second, and then a 10 nm thick first cathode layer made of MgAg (volume ratio 9: 1) is formed. Two cathode layers 31B were formed at a deposition rate of 0.9 nm / second (Mg) and 0.1 nm / second (Ag). Thereby, the organic electroluminescent element shown in FIG. 1 was completed.

(Experimental Examples 12 and 13)
As the anode 11, an ITO layer having a thickness of 10 nm is formed on the AlNd layer, and the first hole injection layer 31A is formed to have a thickness of 10 nm. Goed through the procedure. When forming the anode 11, an AlNd layer (thickness 150 nm) was formed in the same manner as in Experimental Examples 2 and 11, and then ITO was evaporated. Further, when forming the first hole injection layer 31A, the same as in Experimental Examples 2 and 11 except that the solid content concentration of the solution used for forming the coating film was 1.5% by weight. I made it.

(Experimental Examples 14 and 15)
The same procedure as in Experimental Examples 12 and 13 was performed, except that the thickness of the ITO layer included in the anode 11 was 20 nm and the first hole injection layer 21A was not formed.

(Experimental Examples 16 to 18)
Experimental Example 2, except that the compound (α-NPD) represented by the following formula (10) was used instead of the compound represented by the formula (1-9) which is the compound represented by the formula (1). The same procedure as 12 and 14 was performed.

(Experimental Examples 19 and 20)
When the hole injection layer 21 is formed, the compound represented by the following formula (11) is used in place of the polymer compound mixed material represented by the formula (3-1), the formula (5), and the formula (6). The same procedure as in Experimental Examples 14 and 15 was performed except that was used.

  With respect to the organic electroluminescent elements of Experimental Examples 1 to 20, the driving voltage and the luminous efficiency were measured and the luminous lifetime was evaluated. The results shown in Table 1 were obtained.

When measuring the voltage and luminous efficiency, the current density was set to 10 mA / cm ² . Further, when evaluating the light emission lifetime, the luminance half-life was measured. In this case, the time until the relative luminance with respect to the initial luminance when driving at a current density; average 20 mA / cm ² , duty: 25% was halved was measured. Each of the above measurements was performed in a nitrogen gas atmosphere having an oxygen concentration of 0.5 ppm or less under conditions of an atmosphere temperature of 25 ° C. and a dew point temperature of −80 ° C.

  As shown in Table 1, the hole injection layer 21 containing the polymer compound shown in Formula (3-1), Formula (5), and Formula (6), the compound shown in Formula (1-3), etc. In Experimental Examples 1 to 15 in which the hole transport layer 22 including them was formed, the driving voltage and the light emission efficiency were comparable to those in Experimental Examples 16 to 20 in which the hole transport layer 22 was not formed. On the other hand, in Experimental Examples 1 to 15, the light emission lifetime was significantly longer than in Experimental Examples 16 to 20.

  Specifically, in Experimental Examples 1 to 15 in which the hole transport layer 22 includes the compound represented by Formula (1-3) or the like, compared to Experimental Examples 16 to 18 including the compound represented by Formula (10). The driving voltage and the light emission efficiency were similar, but the light emission lifetime was increased 2 to 3 times. Further, in Experimental Examples 14 and 15 in which the hole injection layer 21 includes the polymer compound represented by Formula (3-1), Formula (5), or Formula (6), the experiment including the compound represented by Formula (11) Compared with Examples 19 and 20, the driving voltage and the luminous efficiency were comparable, but the luminance half-life was about twice as long. This result represents the following. That is, the organic layer 20 has a formula (1) together with a hole injection layer 21 containing a thiophene derivative such as a polymer compound represented by formula (3-1) and an organic acid represented by formulas (5) and (6). And 3) a hole transport layer 22 including the compound shown in FIG. Accordingly, the efficiency of injecting holes into the light emitting layer 23 is favorably maintained for a long time without depending on the configuration of the anode 11 and the presence or absence of the first hole injection layer 21A.

  In addition, in Experimental Examples 12 and 13 in which a layer made of ITO is formed on the organic layer 20 side of the anode 11, compared with Experimental Examples 2 and 11 in which the layer is not formed, the driving voltage, the light emission efficiency, and the luminance half-life are reduced. It was about the same. Further, in the experimental examples 2 and 11 in which the first hole injection layer 21A is formed, the driving voltage, as compared with the experimental examples 14 and 15 in which a layer made of ITO is formed on the organic layer 20 side of the anode 11 instead. The luminous efficiency and luminance half life were comparable.

  From these things, the following was confirmed in the organic electroluminescent element of the present Example. That is, the organic layer 20 has the hole transport layer 22 containing at least one of the compounds represented by the formulas (1) and (2) together with the hole injection layer 21 containing the thiophene derivative and the organic acid. Thus, the life characteristics can be improved.

  The present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the embodiments described in the above embodiments and examples, and various modifications can be made. For example, in the above-described embodiments and examples, the top emission organic electroluminescent element has been described, but a bottom emission type may be used. In this case, the substrate is made of a transparent material, and the cathode, the organic layer, and the anode are stacked in this order on the substrate, and the organic layer is sequentially stacked from the cathode side, the electron transport layer, the light emitting layer, and the hole transport. It has a structure in which a layer and a hole injection layer are stacked.

  In the above-described embodiment, an active matrix display device has been described. However, a passive display device may be used.

It is sectional drawing showing the structure of the organic electroluminescent element which concerns on one embodiment of this invention. It is sectional drawing showing the structure of the display apparatus provided with the organic electroluminescent element which concerns on one embodiment of this invention. It is sectional drawing for demonstrating the structure of the conventional organic electroluminescent element.

Explanation of symbols

  1R, 1B, 1G ... organic electroluminescent element, 10 ... substrate, 11 ... anode, 12 ... insulating layer, 20 ... organic layer, 21 ... hole injection layer, 21A ... first hole injection layer, 21B ... second positive Hole injection layer, 22 ... hole transport layer, 23 ... light emitting layer, 24 ... electron transport layer, 30 ... substrate for sealing, 31 ... cathode, 31A ... first cathode layer, 31B ... second cathode layer, 32 ... protection Layer 33 ... Adhesive layer.

Claims (7)

An organic layer including a light emitting layer is provided between the anode and the cathode,
The organic layer includes a first layer containing a thiophene derivative and an organic acid, and a compound represented by the formula (1) and the formula (2), in order from the anode side, between the anode and the light emitting layer. An organic electroluminescence device having a second layer including at least one of them laminated.

(R1 and R2 are each independently an aromatic carbocyclic group or an aromatic heterocyclic group, or a group having one or more substituents introduced therein. R3 to R10 are each independently a hydrogen atom, Halogen atom, alkyl group, aralkyl group, alkenyl group, cyano group, amino group, acyl group, alkoxycarbonyl group, carboxyl group, alkoxy group, aryloxy group, alkylsulfonyl group, hydroxyl group, amide group, aromatic carbocyclic group or An aromatic heterocyclic group, or a group in which one or two or more substituents are introduced thereto, and adjacent ones of R3 to R10 may be bonded to form a ring structure. Among the divalent aromatic carbocyclic group, the divalent aromatic carbocyclic group having a substituent, the divalent aromatic heterocyclic group, and the divalent aromatic heterocyclic group having a substituent are few. Both one is one to four linked formed by linking group.)

(X1 is an N-carbazoyl group, N-phenoxadiyl group or N-phenothiadiyl group, or a group in which one or more substituents are introduced. X2 is an N-carbazoyl group, N-phenoxadiyl group. A group, an N-phenothiadiyl group, a group into which one or more substituents are introduced, or -N (Y1) (Y2)-, wherein Y1 and Y2 are aromatic carbocyclic groups or aromatic heterocyclic rings R11 and R12 each independently represents a hydrogen atom, an alkyl group, an aromatic carbocyclic group, an aromatic heterocyclic group or an aralkyl group, or And R13 and R14 each independently represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group. Aromatic carbocyclic group or aromatic heterocyclic group, or a thereof to 1 or 2 or more substituents are introduced group.) The thiophene derivative is a polymer compound represented by the formula (3),
The organic electroluminescent element according to claim 1, wherein the organic acid is at least one of organic acids represented by formulas (4) to (6).

(R21 is an alkylene group having 1 to 5 carbon atoms, or a divalent group in which a substituent is introduced into an alkylene group having 1 to 5 carbon atoms. Z1 is an oxygen atom or a sulfur atom. Q is 1 or more. (It is an integer.)

(R31 and R32 are each independently a carboxyl group or a hydroxyl group. B1 is a trivalent group having a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring or heterocyclic ring.)

(X, y and z are each independently an integer of 1 or more.)

(P is an integer of 1 or more.) The organic electroluminescent element according to claim 1, wherein the organic layer has a layer containing an aniline derivative and an organic acid between the anode and the first layer. The aniline derivative is a polymer compound represented by the formula (7),
The organic electroluminescent element according to claim 3, wherein the organic acid is at least one of organic acids represented by formulas (4) to (6).

(R41 to R45 are each independently a hydrogen atom, a saturated hydrocarbon group, an unsaturated hydrocarbon group, a saturated hydrocarbon oxy group, an unsaturated hydrocarbon oxy group, an aryl group, an aryl group having a substituent, an aryloxy group, An aryloxy group having a substituent, a heterocyclic group, or a heterocyclic group having a substituent, and L4 to L6 each independently represent a divalent group having a benzene ring skeleton or a naphthalene ring skeleton; Each n is independently an integer of 0 or more, and satisfies (l + m + n) ≧ 1.)

(R31 and R32 are each independently a carboxyl group or a hydroxyl group. B1 is a trivalent group having a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring or heterocyclic ring.)

(X, y and z are each independently an integer of 1 or more.)

(P is an integer of 1 or more.) The anode has light reflectivity and the cathode has light transmittance,
The organic electroluminescent element according to claim 1, wherein light emitted from the light emitting layer is emitted from the cathode side. The organic electroluminescent element according to claim 5, wherein the anode contains aluminum as a main component and an element having a relatively lower work function than aluminum as a subcomponent. An organic electroluminescent device having an organic layer including a light emitting layer between an anode and a cathode,
The organic layer includes a first layer containing a thiophene derivative and an organic acid, and a compound represented by the formula (1) and the formula (2), in order from the anode side, between the anode and the light emitting layer. A display device including a second layer including at least one of them.

(R1 and R2 are each independently an aromatic carbocyclic group or an aromatic heterocyclic group, or a group having one or more substituents introduced therein. R3 to R10 are each independently a hydrogen atom, Halogen atom, alkyl group, aralkyl group, alkenyl group, cyano group, amino group, acyl group, alkoxycarbonyl group, carboxyl group, alkoxy group, aryloxy group, alkylsulfonyl group, hydroxyl group, amide group, aromatic carbocyclic group or An aromatic heterocyclic group, or a group in which one or two or more substituents are introduced thereto, and adjacent ones of R3 to R10 may be bonded to form a ring structure. Among the divalent aromatic carbocyclic group, the divalent aromatic carbocyclic group having a substituent, the divalent aromatic heterocyclic group, and the divalent aromatic heterocyclic group having a substituent are few. Both one is one to four linked formed by linking group.)

(X1 is an N-carbazoyl group, N-phenoxadiyl group or N-phenothiadiyl group, or a group in which one or more substituents are introduced. X2 is an N-carbazoyl group, N-phenoxadiyl group. A group, an N-phenothiadiyl group, a group into which one or more substituents are introduced, or -N (Y1) (Y2)-, wherein Y1 and Y2 are aromatic carbocyclic groups or aromatic heterocyclic rings R11 and R12 each independently represents a hydrogen atom, an alkyl group, an aromatic carbocyclic group, an aromatic heterocyclic group or an aralkyl group, or And R13 and R14 each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. Aromatic carbocyclic group or aromatic heterocyclic group, or a thereof to 1 or 2 or more substituents are introduced group.)

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