Dicyanonaphthalene-ylidene derivative and organic light-emitting element using the same

Abstract

To provide a dicyanonaphthalene-ylidene derivative which has excellent thermal stability, has low vapor deposition temperature, and is useful as a hole injection material, and an organic electroluminescent element using the same.SOLUTION: A dicyanonaphthalene-ylidene derivative is represented by general formula (1). In formula (1), Ar is an unsubstituted aromatic ring having 6 to 24 ring carbon atoms and heterocycle having 5 to 24 ring atoms, a substituted aryl group having 6 to 60 ring carbon atoms, pyridyl group, and quinolyl group, a substituted or unsubstituted 1-50C alkyl group, cycloalkyl group having 3 to 50 ring carbon atoms, 7-50C aralkyl group, 1-50C alkoxy group, aryloxy group having 6 to 50 ring carbon atoms, arylthio group having 6 to 50 ring carbon atoms, 2-50C alkoxy carbonyl group, amino group substituted with an aryl group having 6 to 50 ring carbon atoms, and a halogen atom, a trifluoromethyl group, a cyano group, a nitro group, a hydroxy group, or a carboxy group.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an electron-accepting organic material used as a material for a hole injection layer of a photoelectric conversion layer, and an organic light-emitting device using the same. [Background technology]

[0002] Organic electroluminescent devices (OLEDs) are often used in industrial displays due to their self-luminous, high brightness, wide viewing angle, faster response, and simple manufacturing process. In recent years, with the development and widespread application of electronic products such as mobile phones, personal digital assistants, and notebook computers, there is an increasing demand for flat display devices that consume less power and occupy less space.

[0003] Conventional organic electroluminescent devices generally rely on intrinsic semiconductor materials and have a non-doped hole injection layer, which results in higher driving voltages and power consumption compared with the same type of liquid crystal display (LCD). In order to reduce the driving voltage and power consumption of organic electroluminescent diodes, OLEDs with pin structure are known. Specifically, the OLEDs have a p-doped hole injection layer.

[0004] Also known is a p-nOLED using F4-TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane) as a p-dopant and m-MTDATA (4,4',4"-tris(3-methylphenylphenylamino)-triphenylamine) as a host for the p-doped layer.

[0005] Patent Document 1 discloses an image display system including an organic electroluminescent diode in which the hole injection layer contains a compound having an F4-TCNQ structure. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-244430 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, F4-TCNQ has low thermal stability and is easily decomposed when evaporated, which reduces the reliability and performance of OLEDs.Furthermore, F4-TCNQ has a low deposition temperature, which makes it difficult to control the amount of dopant in F4-TCNQ.

[0008] In view of the above problems, an object of the present invention is to provide a dicyanonaphthalene ylidene derivative which has excellent thermal stability and is useful as a hole transport layer at a low deposition temperature, and an organic light emitting device using the same. [Means for solving the problem]

[0009] In order to achieve the above object, a first aspect of the present invention is a dicyanonaphthalene ylidene derivative represented by the following general formula (1). [ka] In formula (1), Ar is an unsubstituted aromatic ring having 6 to 24 ring carbon atoms, an unsubstituted heterocycle having 5 to 24 ring atoms, a substituted aryl group having 6 to 60 ring carbon atoms, a substituted pyridyl group, a substituted quinolyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, an amino group substituted with a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a halogen atom, a trifluoromethyl group, a cyano group, a nitro group, a hydroxyl group, or a carboxyl group. R1 to R6 may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted fluoroalkyl group, or a cyano group. Effect of the Invention

[0010] According to the first aspect of the present invention, by using the compound represented by the above formula (1) as a material for the hole injection layer of an organic light-emitting device, a hole injection layer having excellent thermal stability and low deposition temperature can be formed, and the amount of dopant can be easily controlled, thereby improving the reliability and performance of the organic light-emitting device. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a partial cross-sectional view of an organic electroluminescence element 100 according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a partial cross-sectional view of an organic electroluminescence element 100 according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [1. Structure of organic electroluminescence element] First, an organic electroluminescence element using the dicyanonaphthalene ylidene derivative of the present invention will be described. Fig. 1 is a partial cross-sectional view of an organic electroluminescence element (hereinafter simply referred to as organic light-emitting element) 100 according to a first embodiment of the present invention. The organic light-emitting element 100 includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, a light-emitting layer 5, a donor-containing layer 6, an acceptor-containing layer 7, and a light-transmitting cathode 8.

[0013] <Substrate> The substrate 1 is not particularly limited as long as it can be used in the organic light-emitting device 100. The substrate 1 may be transparent or opaque. Examples of the transparent substrate include transparent rigid substrates such as glass such as quartz glass and synthetic quartz plates, and transparent flexible substrates such as transparent resin films and optical resin plates. Transparent flexible substrates have the advantages of being easy to process, reducing manufacturing costs, being lightweight, being less likely to break, and being applicable to curved surfaces.

[0014] <Anode> The anode 2 is a hole injection electrode. Examples of materials used for the anode 2 include gold (Au), silver (Ag), cobalt (Co), nickel (Ni), platinum (Pt), carbon (C), indium tin oxide (ITO), tin oxide (SnO2), fluorine-doped tin oxide (FTO), and zinc oxide (ZnO).

[0015] Furthermore, the material of the anode 2 is appropriately selected in consideration of whether the organic light-emitting element 100 also emits light from the surface on the substrate 1 side. When the substrate 1 is a transparent substrate and emits light from the surface on the substrate 1 side, the anode 2 is preferably a transparent electrode. Examples of materials used when the anode 2 is a transparent electrode include indium zinc oxide (IZO), ITO, FTO, ZnO-Al, and Zn-Sn-O.

[0016] The anode 2 may be a single layer, or may be composed of multiple layers having different work functions.

[0017] The anode 2 may be formed in a sheet shape over the entire surface of the substrate 1, or may be formed in a pattern on the substrate 1. The shape of the anode 2 may be flat or uneven. Examples of the uneven shape include a textured structure, a pyramidal structure, a corrugated structure, a comb structure, and a nanopillow structure. The anode 2 is formed by a method such as sputtering, electron beam evaporation, thermal evaporation, or chemical vapor deposition.

[0018] <Hole injection layer> The hole injection layer 3 is laminated between the anode electrode 2 and the hole transport layer 4. The hole injection layer 3 is provided so as to facilitate the injection (movement) of holes from the anode 2 (hole injection electrode) to the hole transport layer 4.

[0019] In the organic light-emitting device 100 of this embodiment, the hole injection layer 3 contains a dicyanonaphthalene ylidene derivative represented by the following general formula (1). The hole injection layer 3 may contain only the dicyanonaphthalene ylidene derivative represented by the general formula (1), or may further contain an additive. As the additive, a conventionally known additive such as an interface treatment agent can be used.

[0020] [ka]

[0021] In formula (1), Ar is an unsubstituted aromatic ring having 6 to 24 ring carbon atoms, an unsubstituted heterocycle having 5 to 24 ring atoms, a substituted aryl group having 6 to 60 ring carbon atoms, a substituted pyridyl group, a substituted quinolyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, an amino group substituted with a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a halogen atom, a trifluoromethyl group, a cyano group, a nitro group, a hydroxyl group, or a carboxyl group. R1 to R6 may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted fluoroalkyl group, or a cyano group.

[0022] Specific examples of the dicyanonaphthalene ylidene derivative represented by the general formula (1) include compounds (1-1) to (1-7) represented by the following chemical formulas. The thermal property data (sublimation temperature) of compounds (1-1) to (1-7) are shown in Table 1 in comparison with F4-TCNQ.

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [Table 1]

[0032] As shown in Table 1, the deposition temperatures of the compounds (1-1) to (1-8) are all relatively low, at 200° C. or less, but are higher than the deposition temperature of F4-TCNQ (100° C.). Therefore, it is easier to control the amount of dopant compared to F4-TCNQ.

[0033] By using the compound represented by the above formula (1) as a dopant material (electron-accepting material) constituting the hole injection layer 3, it is possible to improve the mobility of charges (electrons), thereby improving the luminous efficiency of the organic light-emitting element 100. In addition, since the compound represented by the above formula (1) has excellent thermal stability and requires a low deposition temperature, the organic light-emitting element 100 can be easily manufactured, and the reliability is also improved.

[0034] In the compound represented by the above formula (1), the electron-withdrawing property of the R1 to R6 groups is based on the electron-withdrawing property, and the more electron-withdrawing groups there are as substituents on the Ar group, the greater the electron-withdrawing property of the compound itself, and the better the performance as a dopant. For example, compound (1-7) has no electron-withdrawing substituents on the Ar group, and only the electron-withdrawing properties of the nitrile group and fluorine atom are present. Examples of compounds in which the Ar group does not have an electron-withdrawing group include compounds (1-9) to (1-11) represented by the following chemical formulas.

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] Compounds (1-1) to (1-4) have one electron-withdrawing trifluoromethyl group, nitrile group, or nitro group as a substituent of the Ar group. Examples of compounds in which the Ar group has one electron-withdrawing group include compounds (1-12) to (1-17) represented by the following chemical formulas.

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] Compound (1-5) has two electron-withdrawing trifluoromethyl groups as substituents of the Ar group. Examples of compounds in which the Ar group has two electron-withdrawing groups include compounds (1-18) to (1-22) represented by the following chemical formulas.

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka]

[0051] Compounds (1-6) and (1-8) have five electron-withdrawing fluorine atoms or nitrile groups as substituents of the Ar group. Examples of compounds in which the Ar group has three or more electron-withdrawing groups include compounds (1-23) to (1-27) represented by the following chemical formulas.

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] <Hole transport layer> The hole transport layer 4 is laminated between the hole injection layer 3 and the light emitting layer 5. The hole transport layer 4 is provided so as to facilitate the injection (movement) of holes from the hole injection layer 3 to the light emitting layer 5. By laminating the hole injection layer 3 and the hole transport layer 4, the efficiency of hole injection from the anode 2 to the light emitting layer 5 is increased, and the luminous efficiency of the organic light emitting element 100 is improved.

[0058] <Light-emitting layer> The light-emitting layer 5 is laminated between the hole transport layer 4 and the donor-containing layer 6. The light-emitting layer 5 contains a light-emitting material that emits light due to the recombination energy of holes injected from the anode 2 and electrons injected from the light-transmitting cathode 8. The light-emitting layer 5 may contain a light-emitting material alone, or may contain a light-emitting material and a host material. In order for the organic light-emitting device 100 to exhibit high luminous efficiency, it is important to confine the singlet excitons and triplet excitons generated in the light-emitting material in the light-emitting material. Therefore, it is preferable to add a host material to the light-emitting layer 5 in addition to the light-emitting material.

[0059] The light-emitting material may be one or more selected from a group of conventionally known compounds. The host material may be an organic compound having at least one of the excited singlet energy and the excited triplet energy higher than that of the light-emitting material. The host material is preferably an organic compound having hole transporting ability and electron transporting ability, preventing the emission from becoming longer in wavelength, and having a high glass transition temperature. The light emission of the light-emitting layer 5 is generated from the light-emitting material contained in the light-emitting layer 5. This light emission includes both fluorescent emission and delayed fluorescent emission. However, it is acceptable if the light emission is partly or partially from the host material.

[0060] <Donor-containing layer> The donor-containing layer 6 is laminated between the light-emitting layer 5 and the acceptor-containing layer 7. The donor-containing layer 6 is a layer that extracts electrons from the acceptor-containing layer 7 and injects electrons into the light-emitting layer 5 (donates electrons). By providing the donor-containing layer 6, the large difference in affinity level between the light-emitting layer 5 and the acceptor-containing layer 7 can be eliminated, making it easier to accept electrons from the acceptor-containing layer 7.

[0061] <Acceptor-containing layer> The acceptor-containing layer 7 is laminated between the donor-containing layer 6 and the light-transmitting cathode 8. The acceptor-containing layer 7 is provided so as to facilitate the injection (transfer) of electrons from the light-transmitting cathode 8 (electron injection electrode) to the donor-containing layer 6. An easily reducible organic compound can be used as the acceptor-containing layer 7. The ease of reduction of a compound can be measured by its reduction potential. In the present invention, the reduction potential, using a saturated calomel (SCE) electrode as a reference electrode, is preferably -0.8 V or higher, more preferably -0.3 V or higher, and particularly preferably a compound having a value higher than the reduction potential of tetracyanoquinodimethane (TCNQ) (about 0 V).

[0062] By providing the acceptor-containing layer 7 between the donor-containing layer 6 and the light-transmitting cathode 8, the acceptor contained in the acceptor-containing layer 7 extracts electrons from the contact surface between the acceptor-containing layer 7 and the light-transmitting cathode 8. Since the acceptor-containing layer 7 has electron transport properties, electrons are transported from this contact surface into the acceptor-containing layer 7 in the direction of the donor-containing layer 6. Furthermore, electrons are injected from the donor-containing layer 6 in the direction of the light-emitting layer 5. Meanwhile, holes are injected from the anode 2 into the hole injection layer 3 and the hole transport layer 4, and further into the light-emitting layer 5. The holes and electrons recombine in the light-emitting layer 5 to emit light.

[0063] In the organic light-emitting element 100 of this embodiment, the acceptor-containing layer 7 and the donor-containing layer 6 are provided between the light-transmitting cathode 8 and the light-emitting layer 5, which facilitates the injection (transfer) of electrons from the light-transmitting cathode 8 to the light-emitting layer 5, thereby enabling the organic light-emitting element 100 to have a lower driving voltage, higher efficiency, and longer life.

[0064] <Light transparent cathode> The light-transmitting cathode 8 is an electron injection electrode laminated on the acceptor-containing layer 7. The light-transmitting cathode 8 is provided opposite the anode 2. The light-transmitting cathode 8 is not particularly limited as long as it has electrical conductivity. The material of the light-transmitting cathode 8 is appropriately selected in consideration of the material of the acceptor-containing layer 7, for example.

[0065] Examples of materials used for the light-transmitting cathode 8 include indium tin oxide (ITO), tin oxide (SnO 2 ), fluorine-doped tin oxide (FTO), and zinc oxide (ZnO).

[0066] The light-transmitting cathode 8 may be a single layer. The second electrode 6 may be composed of a plurality of layers having different work functions. The light-transmitting cathode 8 may be formed in a sheet shape on the entire surface of the acceptor-containing layer 7, or may be formed in a pattern on the acceptor-containing layer 7.

[0067] <Other components> The organic light-emitting device 100 may further include other components as necessary in addition to the above-mentioned substrate 1, anode 2, hole injection layer 3, hole transport layer 4, light-emitting layer 5, donor-containing layer 6, acceptor-containing layer 7, and light-transmitting cathode 8. Examples of the other components include a protective sheet layer, a filler layer, a barrier layer, a protective hard coat layer, a strength support layer, an antifouling layer, a high light reflection layer, an ultraviolet blocking layer, an infrared blocking layer, and an encapsulant layer. In addition, the organic light-emitting device 100 may have an adhesive layer laminated between each layer as necessary.

[0068] The organic light-emitting device 100 of this embodiment is not limited to the configuration shown in Fig. 1. For example, the hole injection layer 3 and the hole transport layer 4 are optional layers and can be omitted, and an electron transport layer or the like can be laminated between the light-emitting layer 5 and the donor-containing layer 6. The hole injection layer 3, the hole transport layer 4, the light-emitting layer 5, the electron transport layer, and the like correspond to the organic thin film layers in the organic light-emitting device 100 of this embodiment. In addition, a buffer layer may be formed between the light-transmitting cathode 8 and the acceptor-containing layer 7.

[0069] The configuration of the organic light-emitting element 100 of the present invention has been described above by taking the organic light-emitting element 100 of the first embodiment shown in Fig. 1 as an example, but the present invention is not limited to the configuration of the organic light-emitting element 100 of the first embodiment. For example, the organic light-emitting element may be a stack-type multi-photon emission element (MPE element) in which two or more light-emitting units are sandwiched between the anode 2 and the light-transmitting cathode 8 and a charge generation layer is laminated between the light-emitting units.

[0070] 2 is a schematic cross-sectional view of an organic light-emitting device 100 according to a second embodiment of the present invention. The organic light-emitting device 100 of this embodiment includes an anode 2, a first light-emitting unit 10, a charge generating layer 11, a second light-emitting unit 12, a donor-containing layer 6, an acceptor-containing layer 7, and a light-transmitting cathode 8, in this order, on a substrate 1. The two light-emitting units 10 and 12 each have a single layer or laminated structure having at least a light-emitting layer. For example, the light-emitting units 51 and 53 preferably have a multilayer structure in which a hole transport layer, a light-emitting layer, and an electron transport layer are laminated from the anode 2 side.

[0071] The organic light-emitting element 100 has the same configuration as the organic light-emitting element 100 of the first embodiment shown in Fig. 1, except that two light-emitting units are formed. In other words, the organic light-emitting element 100 of the first embodiment has a device configuration having one light-emitting unit composed of a hole injection layer 3, a hole transport layer 4, and a light-emitting layer 5.

[0072] In this embodiment, for example, the materials of the light-emitting layers constituting the light-emitting units 10 and 12 are changed to vary the emitted light color, thereby obtaining an organic light-emitting device 100 that emits white light.

[0073] The organic light-emitting device 100 of this embodiment is not limited to the configuration shown in Fig. 2. For example, in each of the light-emitting units 10 and 12 of the organic light-emitting device 100 of this embodiment, the above-mentioned donor-containing layer and acceptor-containing layer may be laminated between the light-emitting layer and the charge generating layer. Specifically, the first light-emitting unit 10 may have a configuration in which a hole transport layer, a light-emitting layer, a donor-containing layer, and an acceptor-containing layer are laminated from the anode 2 side.

[0074] The present invention is not limited to the above-mentioned embodiments, and various modifications are possible within the scope of the present invention. For example, in the above-mentioned embodiments, the dicyanonaphthalene ylidene derivative of the present invention is used in the acceptor-containing layer 7 of the organic light-emitting element 100, but it can also be used as an acceptor layer of an organic solar cell. The effects of the present invention will be described more specifically below with reference to examples. EXAMPLES

[0075] [Synthesis example of intermediate product (a-1)] Under a nitrogen atmosphere, 3.72g (20mmol) of hexafluorobenzene represented by chemical formula (A) and 3.70g (20mmol) of 4-trifluoromethylbenzylnitrile represented by chemical formula (B) were added to a dimethylformamide solution of 3.32g (24mmol) of potassium carbonate, and the mixture was stirred at room temperature for 15 hours. The reaction solution was poured into water, acidified with hydrochloric acid, and then extracted with chloroform. The mixture was purified by silica gel column chromatography to obtain 3.16g of intermediate product (a-1) (yield 45%). The synthesis scheme is shown below.

[0076] [ka]

[0077] [Synthesis example of intermediate product (b-1)] Under a nitrogen atmosphere, 2.11 g (32 mmol) of malononitrile was added dropwise to a solution of 1.20 g (30 mmol) of 60% sodium hydride in anhydrous tetrahydrofuran at 0°C, and the mixture was stirred for 1 hour. 3.50 g (10 mmol) of intermediate product (a-1) was added dropwise to the reaction solution, which was then heated to 80°C and stirred under reflux for 8 hours. The reaction solution was poured into water, acidified with hydrochloric acid, and extracted with chloroform. The mixture was purified by silica gel column chromatography to obtain 1.98 g of intermediate product (b-1) (yield 50%). The synthesis scheme is shown below.

[0078] [ka]

[0079] [Synthesis example of dicyanonaphthalene ylidene derivative (1-1)] Under a nitrogen atmosphere, 0.80 g (2 mmol) of intermediate product (b-1) was dissolved in 20 mL of anhydrous acetonitrile, and the solution was cooled to 0°C. Then, 16 g (4 mmol) of 2% bromine water was added dropwise, and the mixture was stirred for 1 hour while returning to room temperature. The reaction solution was poured into water, and the precipitated solid was filtered off, washed twice with water and twice with ether, and dried to obtain 0.24 g of compound (1-1) (yield 30%, H-NMR 600 MHz; 7.64 (dd, 2H), 7.79 (d, 2H) CDCl3). The synthesis scheme is shown below.

[0080] [ka] EXAMPLES

[0081] [Synthesis examples of dicyanonaphthalene ylidene derivatives (1-2) to (1-7)] Dicyanonaphthalene ylidene derivatives (1-2) to (1-7) were synthesized in the same manner as in Example 1, except that compounds (A) and (B) were changed. The yields and yields of intermediate products (a-2) to (a-7), intermediate products (b-2) to (b-7), and dicyanonaphthalene ylidene derivatives (1-2) to (1-7) are shown in Table 2.

[0082] [Table 2] EXAMPLES

[0083] [Example of manufacturing an organic electroluminescence device using a dicyanonaphthalene ylidene derivative as a dopant material] A mixed layer (light-emitting layer) of SPIRO-MeOTAD as a host material and the compounds (1-1) to (1-5) and (1-8) obtained in Examples 1 and 2 as dopant materials was laminated on a glass substrate by mixed thermal evaporation in a high vacuum chamber to obtain inventions 1 to 6. In addition, a mixed layer (light-emitting layer) of SPIRO-MeOTAD and F4-TCNQ was laminated on a glass substrate to obtain a comparative example.

[0084] The doping concentration was 5 mol% and the thickness of the thin film was 50 nm. The glass substrate had two ITO (Indium tin oxide) strips as electrodes for the thin film. These two ITO strips were spaced 1 mm apart. The conductivity of the mixed layer was measured from the current-voltage characteristics of the thin film. The results are shown in Table 3.

[0085] [Table 3]

[0086] As is clear from Table 3, inventions 1 to 6, which used compounds (1-1) to (1-5) and (1-8) as the dopant material, showed electrical conductivity equal to or higher than that of the comparative example, which used F4-TCNQ as the dopant material. In particular, inventions 1 to 3 and 6, which used compounds (1-1) to (1-3) and (1-8), showed higher electrical conductivity than the comparative example. From the above results, it was confirmed that the OLED characteristics were improved by using a dicyanonaphthalene ylidene derivative as the dopant material. [Industrial Applicability]

[0087] The present invention can be used for a dicyanonaphthalene ylidene derivative used as a material for a hole transport layer, and for an organic light emitting device using the same. By using the present invention, it is possible to provide a dicyanonaphthalene ylidene derivative having excellent thermal stability and a low deposition temperature, which is useful as a hole transport layer, and an organic light emitting device using the same. [Explanation of symbols]

[0088] 1 Board 2 Anode 3. Hole injection layer 4. Hole transport layer 5. Light-emitting layer 6 Donor-containing layer 7. Acceptor-containing layer 8 Light-transparent cathode 10 First light emitting unit 11 Charge generating layer 12 Second light emitting unit 100 Organic electroluminescence element (organic light-emitting element)

Claims

1. A dicyanonaphthalene ylidene derivative represented by the following general formula (1): 【Chemistry 1】 (In formula (1), Ar represents an unsubstituted aromatic ring having 6 to 24 ring carbon atoms, an unsubstituted heterocycle having 5 to 24 ring atoms, a substituted aryl group having 6 to 60 ring carbon atoms, a pyridyl group, a quinolyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, an amino group substituted with a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a halogen atom, a trifluoromethyl group, a cyano group, a nitro group, a hydroxyl group, or a carboxyl group. R １ ~R ４ may be the same or different and each represents a hydrogen atom, a halogen atom, a substituted or unsubstituted fluoroalkyl group, or a cyano group.

2. The dicyanonaphthalene ylidene derivative according to claim 1, characterized in that the general formula (1) is any one of the following chemical formulas (1-1), (1-2), (1-3), (1-4), (1-5), or (1-8). 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 【Chemistry 6】 【Chemistry 9】

3. A substrate; an anode laminated on the substrate; one or more organic thin film layers including a light-emitting layer laminated on the anode; a donor-containing layer laminated on the organic thin film layer; an acceptor-containing layer disposed on the donor-containing layer; a light-transmitting cathode laminated on the acceptor-containing layer; Equipped with the organic thin film layer has a hole injection layer between the anode and the light emitting layer, An organic electroluminescence device comprising the dicyanonaphthalene ylidene derivative according to claim 1 or 2 as the hole injection layer.

4. 4. The organic electroluminescence device according to claim 3, wherein the one or more organic thin film layers including the light-emitting layer constitute two or more light-emitting units stacked via a charge generating layer.

5. 5. The organic electroluminescence device according to claim 4, wherein at least one material constituting the light-emitting layer of the light-emitting unit is different from materials constituting the light-emitting layers of the other light-emitting units.

6. The organic electroluminescence device according to claim 3 , wherein the light-emitting layer emits white light.

Images