KR20130051321A - Novel tetiary aryl amine and organic electroluminescent device using the same - Google Patents

Abstract

PURPOSE: A tertiary arylamine is provided to have economic synthesis process, to have excellent hole transfer and electron transfer ability by an asymmetric structure, to lower the generation of crystalline, and to improve the lifetime of a device. CONSTITUTION: A tertiary arylamine is represented by chemical formula 1. In chemical formula 1, each of Ar1 and Ar2 is C4-25 arylene and C4-25 heteroarylene; each of a1 and a2 is selected from H, C4-25 aryl group, C4-25 heteroaryl and C4-25 heteroarylene; each of a1 and a2 is selected from H, C4-25 aryl group, C4-25 heteroaryl, amino, and substituted amino group; Y is C or N; a3 is an unshared electron pair when Y is N; a4 is selected from H, C1-13 alkyl group, C4-25 aryl group, and C4-25 heteroaryl group; if Y is C, each of a3 and a4 is selected from H, C1-13 alkyl group, C4-25 aryl group, and C4-25 heteroaryl group, or a structure connected by a C4-20 ring.

Description

Novel tertiary aryl amine and organic electroluminescent device including the same {NOVEL TETIARY ARYL AMINE AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME}

The present invention relates to a novel tertiary aryl amine and an organic light emitting device including the same.

Recently, the organic light emitting diode, which has been spotlighted as the next-generation flat display, has been actively researched and developed due to the advantages of low driving voltage, fast response speed, high efficiency, and wide viewing angle, compared to liquid crystal displays.

The criteria for the basic performance of the display device are driving voltage, power consumption, efficiency, brightness, contrast, response time, lifetime, display color (color coordinate) and color purity. One of the non-luminous display devices, LCD, is the most widely used because of its light weight, low power consumption. However, the characteristics such as response time, contrast, viewing angle, etc. have not reached a satisfactory level, and there is still much room for improvement. Therefore, organic light-emitting diodes (OLEDs) are attracting attention as next-generation display devices that can compensate for these problems. OLEDs are self-luminous display devices that have wide viewing angles, excellent contrast, and fast response times.

A general organic light emitting device is a self-light emitting device using a principle that electrons and holes injected through a cathode and an anode form an exciton having recombination energy in an organic thin film, and light of a specific wavelength is generated from the formed excitons.

Since organic light emitting materials were first discovered from anthracene single crystals by Pope et al. In 1965, organic light emitting diodes have an organic light-emitting structure having a laminated structure of a functional separation type in which an organic material is divided into a hole receiving layer and a light emitting layer by Tang's Tang in 1987. Since the diode has been proposed, "low voltage driving organic EL devices by stacked devices" (CWTang, SAVanslyke, Applied Physics Letters, 1987, 51 , 913), materials for light-emitting devices including various kinds of organic materials have been developed so far. .

These light emitting materials are largely divided into fluorescence and phosphorescence, and a light emitting layer forming method includes a method of doping phosphorescent dopants in a fluorescent host, a method of increasing quantum efficiency by doping a fluorescent host in a fluorescent host, and a plate on a light emitting body. The light emission wavelength is shifted to a long wavelength by using a light (DCM, Rubrene, DCJTB, etc.). Through such doping, the emission wavelength, efficiency, driving voltage, and lifespan are improved.

The structure of a general organic EL device includes an anode, a hole injection layer (HIL) that receives holes from an anode, a hole transport layer (HTL) that transports holes, an emission layer (EML) that combines holes and electrons, and emits electrons. It consists of an electron transport layer (ETL) and a cathode which receive from and deliver to a light emitting layer. Such a thin film structure formed by the vacuum evaporation method can adjust the moving speed of holes and electrons to balance the densities of holes and electrons in the light emitting layer, thereby enhancing the luminous efficiency. In addition, in order to commercialize and improve the characteristics of the organic electroluminescent device, not only the device is configured in a multilayer structure as described above, but also the device material, in particular, the hole transport material must be thermally and electrically stable. This is because molecules with low thermal stability due to the heat generated from the device when the voltage is applied are low in crystal stability and are rearranged, resulting in local crystallization and deterioration and destruction of the device.

The hole transport materials that have been used up to now include m-MTDATA [4,4 ', 4 "-tris (N-3-methylphenyl-N-phenylamino) -triphenylamine], 2-TNATA [4,4', 4 "-Tris (N- (naphthylene-2-yl) -N-phenylamino) -triphenylamine], TPD [N, N'-diphenyl-N, N'-di (3-methylphenyl) -4, 4'-diaminobiphenyl] and NPB [N, N'-di (naphthalen-1-yl) -N, N'-diphenylbenzidine]. M-MTDATA and 2-TNATA have a glass transition temperature ( Tg) is not only low, but also a lot of problems occur in the process of mass production, there is a problem in realizing the total color, TPD and NPB also have a low glass transition temperature of 60 ℃ and 96 ℃, respectively, There is a fatal disadvantage of shortening the lifespan. Among them, NPB has a low singlet excitation energy, so that energy can be transferred from the light emitting layer in the excited state during device driving. In particular, when the light emitting layer is blue, since the energy gap in the excited state is large because of the short wavelength, the energy of the light emitting layer is likely to be transferred to the NPB layer. As a result, there is a problem that the luminous efficiency of the device is lowered due to the energy transfer to NPB.

In addition, the conventional aryl amine compound has a structure including both a 9,9-diphenyl-9H-fluorene group, a 9-phenyl-9H-carbazole group, and the like, and the synthesis process for the substituent itself is complicated and finally This results in problems such as low yields, very expensive synthesis costs.

Therefore, there is an urgent need for research on excellent materials capable of economically synthesizing hole transport materials used in organic light emitting diodes and improving their performance.

The present invention provides a tertiary aryl amine compound having an asymmetric structure to solve the above problems.

The present invention also provides an organic electroluminescent device comprising the tertiary aryl amine compound.

The present invention provides a tertiary aryl amine represented by the following formula (1).

Formula 1

Ar ₁ and Ar ₂ are the same or different, each selected from an arylene group of C4 ~ C25 and a heteroarylene group of C4 ~ C25,

A ₁ and a ₂ are the same or different, each selected from the group consisting of H, C 4 -C 25 aryl group, C 4 -C 25 heteroaryl group, amino group and substituted amino group,

Y is C or N,

When Y is N, a ₃ is a non-covalent electron pair, a ₄ is any one selected from the group consisting of H, an alkyl group of C 1 -C 13, an aryl group of C 4 -C 25, and a heteroaryl group of C 4 -C 25,

When Y is C, a ₃ and a ₄ are the same or different, and each selected from the group consisting of H, C 1 -C 13 alkyl group, C 4 -C 25 aryl group, and C 4 -C 25 heteroaryl group, or a <_3> and a <_4> are the structures connected with the ring of C4-C20.

Ar ₁ and Ar ₂ of the formula (1) is a phenylene group (phenylene), naphthylene (naphthylene), anthracenylene group (anthracenylene), pyridylene group (pyridylene), quinolinylene group (quinolinylene) and isoquinolinyl Len group (isoquinolinylene) may be any one selected from the group consisting of, but is not limited thereto.

A ₁ and a ₂ in Formula 1 are H, phenyl group (phenyl), naphthyl group (naphthyl), anthracenyl group (anthracenyl), pyridyl group (pyridyl), quinolinyl group (quinolinyl), isoquinolinyl group (isoquinolinyl) ) And N, N-diphenylamino group (N, N-diphenylamino) may be any one selected from the group consisting of, but is not limited thereto.

When Y in Formula 1 is N, a ₃ is a non-covalent electron pair, and a ₄ is H, a C1-C13 alkyl group, a phenyl group, a naphthyl group, anthracenyl group, and an pyridyl group. ), A quinolinyl group (quinolinyl) and isoquinolinyl group (isoquinolinyl) may be any one selected from the group consisting of, but is not limited thereto.

When Y in Formula 1 is C, a ₃ and a ₄ are the same or different, and each of H, C 1 to C 13, an alkyl group, a phenyl group, a naphthyl group, an anthracenyl group, and an pyridyl group (pyridyl), quinolinyl (quinolinyl) and isoquinolinyl (isoquinolinyl) may be any one selected from the group consisting of, but is not limited thereto.

When Y in Formula 1 is C, a ₃ and a ₄ are linked by a ring, and the ring connecting a ₃ and a ₄ may be a C4 to C20 cycloalkyl group or a C4 to C20 aryl group, but is not limited thereto. It doesn't happen.

The structure in which a ₃ and a ₄ are linked by a ring may be a tertiary aryl amine, which is represented by the following Chemical Formula 2, but is not limited thereto.

(2)

Ar ₁ and Ar ₂ are the same or different, each selected from an arylene group of C4 ~ C25 and a heteroarylene group of C4 ~ C25,

A ₁ and a ₂ are the same or different and are each selected from the group consisting of H, C 4 -C 25 aryl group, C 4 -C 25 heteroaryl group, amino group and substituted amino group.

The tertiary aryl amines are flat panel displays, flat emitters, illuminators for surface emitting OLEDs for lighting, flexible emitters, copiers, printers, LCD backlights, meter light sources, display panels, organic electroluminescent devices (OLEDs), organic solar cells (OSCs) The present invention may be applied to any one selected from electronic paper (e-Paper), organophotoreceptor (OPC), and organic transistor (OTFT), but is not limited thereto.

The present invention also provides an organic electroluminescent device comprising a first electrode, a second electrode and at least one organic layer between these electrodes, wherein at least one layer of the organic layer comprises the tertiary aryl amine.

The at least one organic layer may include a light emitting layer, and may further include at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

The tertiary aryl amine according to the present invention has excellent hole transport and electron transport ability due to the asymmetric structure proposed by the present invention, while the synthesis process is economical, and the glass transition temperature is high thermally and electrically to maintain and drive the device. There is little phenomenon of crystallization at the time of the crystallization, and there is an effect of improving the life of the device.

In addition, the organic light emitting device including the tertiary aryl amine according to the present invention has the advantages of high luminous efficiency, long half life of luminance, and high color purity.

1 is a view schematically showing the structure of an organic light emitting device according to an embodiment of the present invention.
2 is a view schematically showing the structure of an organic light emitting diode according to another embodiment of the present invention.
3 is a spectrum of UV / PL of compound 1 of the present invention.
4 is data on the thermal stability of compound 1 of the present invention.

The present invention provides a tertiary aryl amine represented by the following formula (1).

Formula 1

Ar ₁ and Ar ₂ are the same or different, each selected from an arylene group of C4 ~ C25 and a heteroarylene group of C4 ~ C25,

A ₁ and a ₂ are the same or different, each selected from the group consisting of H, C 4 -C 25 aryl group, C 4 -C 25 heteroaryl group, amino group and substituted amino group,

Y is C or N,

When Y is N, a ₃ is a non-covalent electron pair, a ₄ is any one selected from the group consisting of H, an alkyl group of C 1 -C 13, an aryl group of C 4 -C 25, and a heteroaryl group of C 4 -C 25,

When Y is C, a ₃ and a ₄ are the same or different, and each selected from the group consisting of H, C 1 -C 13 alkyl group, C 4 -C 25 aryl group, and C 4 -C 25 heteroaryl group, or a <_3> and a <_4> are the structures connected with the ring of C4-C20.

The tertiary aryl amine represented by Chemical Formula 1 has an asymmetric structure, thereby improving hole (hole) mobility, helping to transport electrons, and increasing thermal stability by increasing glass transition temperature.

In the tertiary aryl amine according to the present invention, Ar ₁ and Ar ₂ of Formula 1 may be the same or different, and may be C 4 to C 25 arylene groups or C 4 to C 25 heteroarylene groups, wherein the C 4 to C 25 The arylene group may be a phenylene group, a naphthylene group or anthracenylene group, and the C4-C25 heteroarylene group may be a pyridylene group, a quinolinylene group, or It may be an isoquinolinylene group, but is not limited thereto.

Tertiary aryl amine according to the present invention is that a ₁ and a ₂ of Formula 1 are the same or different, and may be H, C4 ~ C25 aryl group, C4 ~ C25 heteroaryl group, amino group or substituted amino group, respectively Specifically, the aryl group of C4 ~ C25 may be a phenyl group (phenyl), naphthyl group (naphthyl) or anthracenyl group (anthracenyl), the heteroaryl group of C4 ~ C25 pyridyl group, quinolinyl group (quinolinyl group) Or an isoquinolinyl group, and the substituted amino group may be an N, N-diphenylamino group, but is not limited thereto.

Tertiary aryl amine according to the present invention can be used that Y of the formula (1) is N or C.

When Y in Formula 1 is N, the tertiary aryl amine according to the present invention has a carbazolyl substituent, and when Y in Formula 1 is C, the tertiary aryl amine according to the present invention is fluorene. ) Will have a substituent.

For the carbazole tertiary arylamine having a substituent a ₃ of Formula 1 is a lone pair, a ₄ is H, a heteroaryl group of C1 ~ C13 alkyl group, C4 ~ C25 aryl group or C4 ~ C25 of the intended In this case, the C4 ~ C25 aryl group may be a phenyl group (phenyl), naphthyl group (naphthyl) or anthracenyl group (anthracenyl), the heteroaryl group of C4 ~ C25 pyridyl group (pyridyl), quinolinyl group ( quinolinyl) or isoquinolinyl, but is not limited thereto.

In the case of the tertiary aryl amine having the fluorene substituent, a ₃ and a ₄ in Formula 1 may be the same or different, and each may be H, an alkyl group of C 1 to C 13, an aryl group of C 4 to C 25, or a heteroaryl group of C 4 to C 25, respectively. In this case, the C4 ~ C25 aryl group may be a phenyl group (phenyl), naphthyl (naphthyl) or anthracenyl group (anthracenyl), the heteroaryl group of C4 ~ C25 pyridyl (pyridyl), quinolinyl group ( quinolinyl) or isoquinolinyl, but is not limited thereto.

In addition, in the case of the tertiary aryl amine having the fluorene substituent, a ₃ and a ₄ in Chemical Formula 1 may be linked by a ring, and the ring connecting a ₃ and a ₄ may be a C4 to C20 cycloalkyl group or C4. It may be an aryl group of ~ C20, but is not limited thereto.

Specifically, the structure in which a ₃ and a ₄ are linked by a ring of Formula 1 may be a spiro compound represented by the following Formula 2.

(2)

Ar ₁ , Ar ₂ , a ₁ and a ₂ are as described above.

3 and 4 show data of UV (Ultraviolet) / PL (Photoluminescence) spectrum and thermal stability of the following Compound 1, which is an example of the tertiary aryl amine represented by Chemical Formula 1.

Compound 1

The UV (Ultraviolet) / PL (Photoluminescence) spectrum of FIG. 3 measures the emission wavelength of each compound in order to characterize the OLED. It measures the wavelength at which the most luminescent light is emitted by irradiating light of a wavelength absorbed through UV It is a graph.

The UV (Ultraviolet) / PL (Photoluminescence) spectrum can be obtained through a method known in the art, in the present invention is about 355nm to a solid film prepared by coating a solution containing the compound 1 in the quartz (quartz) The spectrum of FIG. 3 was obtained by irradiating the excitation light of the wavelength, and as shown in FIG. 3, it is expected to have excellent luminous efficiency since it has a maximum emission peak at about 440 nm. However, since the specific value will vary depending on the purity of the compound, the surrounding environment, and the like, the data tendency is more important than the detailed value.

4 is to determine the thermal stability characteristics of the electrolytic transfer material, which can also be evaluated through a method known in the art, in the present invention, the thermogravimetric analysis (TGA) using a constant temperature in the fan under nitrogen atmosphere A sample of Compound 1 was weighed and the change in weight of the sample was measured while increasing the temperature at a constant rate to obtain data on thermal stability. As a result, as shown in FIG. 4, it was confirmed that the thermal decomposition temperature of Compound 1 had excellent thermal stability at about 300 ° C. or higher. Based on this, the tertiary aryl amine represented by Formula 1 according to the present invention was about 300 ° C. It can be seen that the thermal stability is shown even at a high temperature.

The present invention also provides an organic electroluminescent device comprising the tertiary aryl amine.

The organic electroluminescent device may be manufactured by a conventional method and material for manufacturing an organic electronic device except for forming one or more organic material layers including the tertiary aryl amine compound of Chemical Formula 1 described above.

Specifically, the organic light emitting device according to the present invention includes a first electrode, a second electrode and at least one organic layer between the electrodes, at least one layer of the organic layer includes the tertiary aryl amine.

1 and 2, the organic layer includes a hole injection layer, a hole transport layer, an electroluminescence layer, a hole blocking layer, and an electron transport layer. ) And an electron injection layer, and one or two or more layers of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer, and an electron injection layer may be omitted if necessary. Can be.

The tertiary aryl amine represented by Chemical Formula 1 may be formed of the hole injection layer, the hole transport layer, the electroluminescence layer, the hole blocking layer, and the electron transport layer according to the substituent. (Electron Transport Layer) and the electron injection layer (Electron Injection Layer) may be included in one or more organic material layer, in particular, the tertiary aryl amine represented by the formula (1) is included in the hole transport layer because it shows excellent electrical properties and hole transport properties It is preferable to be.

The organic light emitting device may be manufactured by a method commonly used in the art, and non-limiting examples may use known physical vapor deposition (PVD) methods such as sputtering or e-beam evaporation. By depositing a metal or conductive metal oxide or an alloy thereof on the substrate to form an anode, there is formed an organic material layer including a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer and an electron transport layer thereon, It can be prepared by depositing a material that can be used as a cathode thereon.

In addition to the above method, an organic light emitting device may be manufactured by sequentially depositing a cathode material, an organic material layer, and an anode material on a substrate.

The organic material layer may have a multilayer structure including a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, but is not limited thereto and may have a single layer structure. The organic material layer may be formed using a variety of polymer materials by a method such as a solvent process such as spin coating, dip coating, doctor blading, screen printing, inkjet printing, .

As the anode material, a material having a large work function is usually preferred to facilitate hole injection into the organic material layer. Specific examples of the positive electrode material that can be used in the present invention include metals such as vanadium, chromium, copper, zinc and gold or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), titanium oxide (TiO), indium zinc oxide (IZO); ZnO: Al or SnO _2: a combination of a metal and an oxide such as Sb; Conductive polymers such as poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDT), polypyrrole and polyaniline.

The negative electrode material is preferably a material having a small work function to facilitate electron injection into the organic material layer. Specific examples of the negative electrode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead or alloys thereof; Multilayer structures such as LiAl and LiF / Al or LiO ₂ / Al, and the like, but are not limited thereto.

The hole injection material is a material capable of well injecting holes from the anode at low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the positive electrode material and the HOMO of the surrounding organic material layer. In addition, a material having good surface adhesion with the positive electrode and having a planarization ability that can alleviate the surface roughness of the positive electrode is preferable. A material having HOMO and LUMO values larger than the band gap of the light emitting layer is preferable. In addition, materials having high thermal stability in chemical structure are preferable.

Specific examples of the hole injection material include metal porphyrine, oligothiophene, arylamine-based organics, hexanitrile hexaazatriphenylene-based organics, quinacridone-based organics, and perylene-based Organic substances, anthraquinone and polyaniline and polythiophene-based conductive polymers, but are not limited thereto.

As a hole transport material, a material capable of transporting holes from an anode or a hole injection layer to be transferred to a light emitting layer is suitable. Materials having HOMO and LUMO values larger than the bandgap of the light emitting layer are suitable. Also suitable are chemically structurally high thermally stable materials.

Specific examples thereof include an arylamine-based organic material, a conductive polymer, and a block copolymer having a conjugated portion and a non-conjugated portion together, but are not limited thereto.

The light emitting material is a material capable of emitting light in the visible light region by transporting and combining holes and electrons from the hole transport layer and the electron transport layer, respectively, and a material having good quantum efficiency is preferable.

Specific examples include blue-based ADN or MADN (2-methyl-9,10-di (2-napthyl) anthracene) and DPVBi, BAlq, and green Alq3 and other anthracenes, pyrenes, fluorenes, spiros ) Compounds represented by fluorene, carbazole, benzoxazole, benzthiazole and benzimidazole series, and polymeric poly (p-phenylenevinylene), polypyro, polyfluorene, and the like, but are not limited thereto. It is not.

As the hole blocking layer material, a material larger than the HOMO value of light emission is suitable. Also suitable are chemically structurally high thermally stable materials.

Specifically, TPBi and BCP are mainly used, and CBP, PBD, PTCBI, and BPhen may be used, but are not limited thereto.

As the electron transporting material, a material capable of transferring electrons from the cathode well into the light emitting layer, which is highly mobile, is suitable.

Also suitable are chemically structurally high thermally stable materials.

Specific examples include Al complexes of 8-hydroxyquinoline; Complexes including Alq3; Organic radical compounds; Hydroxyflavone-metal complexes and the like, but are not limited thereto.

The organic electroluminescent device according to the present invention may be a front emission type, a back emission type, or a both-sided emission type, depending on the material used. The tertiary aryl amine compound according to the present invention is a flat panel display, a flat light emitter, a light emitter of a light emitting surface emitting OLED, a flexible light emitter, a copier, a printer, an LCD backlight, a meter light source, a display panel, an organic solar cell (OSC), an electronic paper ( Organic electronic devices, such as e-Paper, organic photoconductor (OPC), and organic transistor (OTFT), can also operate on a similar principle to those applied to organic light emitting devices.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples, which are merely used for the purpose of illustrating the present invention and are defined in the claims or the claims. It is not intended to be used to limit the scope of the invention. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Synthetic example  1: Preparation of Compound A

2-bromo-9,9-dimethyl-9H-fluorene (5 g, 18.30 mmol) 1.0 eq, 4-aminobiphenyl (4.65 g, 27.45 mmol) 1.5 eq, Tris (dibenzyldine) in a dried round flask Acetone) dipalladium (0) (335mg, 0.366mmol) 0.02eq, tri-tert-butylphosphine (74mg, 0.366mmol) 0.02eq Sodium tert-butoxide (2.6g, 27.45mmol) After filling, 50 ml of anhydrous toluene was added and stirred under reflux at 85 ° C. for 3 hours.

After the reaction mixture was cooled to room temperature, distilled water was added thereto to complete the reaction. The mixture was extracted with diethyl ether and distilled water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated by column with ethyl acetate and hexane to obtain a compound A (5.3 g, 80%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 9.77 (s, 1H, NH), 7.81 (q, 1H), 7.75 (q, 2H), 7.38 to 7.59 (m, 8H), 7.28 (m, 1H) , 6.75 (d, 1H), 6.52-6.58 (m, 3H), 1.67 (s, 6H)

Synthetic example  2: Preparation of compound B

2-bromo-9,9-dimethyl-9H-fluorene (5g, 18.30mmol) 1.0eq, 4- (naphthalen-1-yl) benzeneamine (6.02g, 27.45mmol) 1.5eq in a dried round flask , Tris (dibenzyldineacetone) dipalladium (0) (335mg, 0.366mmol) 0.02eq, tri-tert-butylphosphine (74mg, 0.366mmol) 0.02eq sodium tert-butoxide (2.6g, 27.45mmol) 1.5 After adding eq and sufficiently filled with nitrogen, 50 ml of anhydrous toluene was added and stirred under reflux for 3 hours at 85 ° C.

After the reaction mixture was cooled to room temperature, distilled water was added thereto to complete the reaction. The mixture was extracted with diethyl ether and distilled water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with ethyl acetate and hexane. The filtrate layer was separated by a column to obtain Compound B (5.3 g, 80%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 9.77 (s, 1H, NH), 8.55 (q, 1H), 8.42 (q, 1H), 7.84 (q, 1H), 7.55-7.67 (m, 5H) , 7.28 ~ 7.46 (m, 6H), 6.52 ~ 6.58 (m, 3H), 5.75 (d, 1H), 1.67 (s, 6H)

Synthetic example  3: Preparation of compound C

3-bromo-9-phenyl-9H-carbazole (5.9 g, 18.30 mmol) 1.0 eq, aniline (2.56 g, 27.45 mmol) 1.5 eq, tris (dibenzyldineacetone) dipalladium (0) in a dried round flask ) (335mg, 0.366mmol) 0.02eq, tri-tert-butylphosphine (74mg, 0.366mmol) 0.02eq Sodium Tert-Butoxide (2.6g, 27.45mmol) The mixture was stirred at reflux for 3 hours at 85 ° C.

After the reaction mixture was cooled to room temperature, distilled water was added thereto to complete the reaction. The mixture was extracted with diethyl ether and distilled water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with ethyl acetate and hexane, and the filtrate was separated by a column to obtain Compound C (5.8 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 9.77 (s, 1H, NH), 8.19 (m, 1H), 7.53 to 7.55 (m, 3H), 7.20 to 7.33 (m, 9H), 6.98 to 7.08 ( m, 2H), 6.60 (d, 1H), 6.20 (q, 1H)

Synthetic example  4: Preparation of compound D

2-bromo-9,9-dimethyl-9H-fluorene (5 g, 18.30 mmol) 1.0 eq, 6-phenylpyridin-3-amine (4.7 g 27.45 mmol) 1.5 eq, Tris (di Benzyldineacetone) dipalladium (0) (335mg, 0.366mmol) 0.02eq, tri-tert-butylphosphine (74mg, 0.366mmol) 0.02eq sodium tert-butoxide (2.6g, 27.45mmol) 1.5eq After fully filled with 50 ml of anhydrous toluene and stirred at reflux for 3 hours at 85 ℃.

After the reaction mixture was cooled to room temperature, distilled water was added thereto to complete the reaction. The mixture was extracted with diethyl ether and distilled water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the resulting mixture was separated with a column with ethyl acetate and hexane to obtain a compound 100 (5.4 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 9.77 (s. 1H, NH), 8.50 (q, 2H), 7.84 (m, 1H), 7.54-7.56 (m, 7H), 7.38 (m, 1H) , 7.28 (m, 1H), 6.98 (m, 1H), 6.75 (d, 1H), 6.55 (m, 1H), 1.67 (s, 6H)

Synthetic example  5: Preparation of Compound E

2-bromo-9,9-spirofluorene (5 g, 12.65 mmol) 1.0 eq, 4- (naphthalen-1-yl) benzeneamine (4.16 g, 18.97 mmol) 1.5 eq, Tris Dibenzyldineacetone) dipalladium (0) (232mg, 0.253mmol) 0.02eq, tri-tert-butylphosphine (51mg, 0.253mmol) 0.02eq sodium tert-butoxide (1.8g, 18.98mmol) 1.5eq After sufficiently filling with nitrogen, 50 ml of anhydrous toluene was added and stirred under reflux at 85 ° C. for 3 hours.

After the reaction mixture was cooled to room temperature, distilled water was added thereto to complete the reaction. The mixture was extracted with diethyl ether and distilled water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated by column with ethyl acetate and hexane to obtain a compound E (5.4 g, 80%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 9.75 (s, 1H, NH), 8.50 (q, 2H), 8.37 (q, 2H), 7.81 (q, 4H), 7.51 to 7.56 (m, 7H) , 7.15 ~ 7.25 (m, 7H), 6.42 ~ 6.38 (m, 3H), 5.65 (d, 1H)

Synthetic example  6: Preparation of Compound F

2-bromo-9,9-spirofluorene (5g, 12.65mmol) 1.0eq, 4-aminobiphenyl (3.21g, 18.97) 1.5eq, tris (dibenzyldineacetone) dipalladium in a dried round flask (0) (232mg, 0.253mmol) 0.02eq, tri-tert-butylphosphine (51mg, 0.253mmol) 0.02eq Sodium tert-butoxide (1.8g, 18.98mmol) 1.5eq was added and filled with nitrogen thoroughly 50 ml of toluene was added and stirred under reflux at 85 ° C. for 3 hours.

After the reaction mixture was cooled to room temperature, distilled water was added thereto to complete the reaction. The mixture was extracted with diethyl ether and distilled water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the obtained mixture was separated with a column by ethyl acetate and hexane to obtain a compound F (4.9 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 9.72 (s, 1H, NH), 8.45 (q, 2H), 8.35 (q, 2H), 7.79 (q, 4H), 7.49 to 7.59 (m, 5H) , 7.13 ~ 7.23 (m, 7H), 6.40 ~ 6.35 (m, 3H), 5.64 (d, 1H)

Synthetic example  7: Preparation of compound 1

Compound A (10 g, 27.66 mmol) 1.0 eq, 1-bromonaphthalene (8.6 g, 41.5 mmol) 1.5 eq, Tris (dibenzyldineacetone) dipalladium (0) (507 mg, 0.553 mmol) 0.02 in a dried round flask eq, tri-tert-butylphosphine (336mg, 1.66mmol,) 0.06eq sodium tert-butoxide (13.3g, 138.32mmol) 5eq was added and filled with sufficient nitrogen, 100ml of anhydrous toluene was added to reflux at 85 ℃ for 20 hours Stir.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane, and the filtrate layer was separated by a column to obtain Compound 1 (11 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.09 (q, 1H), 7.82 (q, 1H), 7.64 (q, 2H), 7.43 (m, 4H), 7.37 (m, 2H), 7.30 (m , 3H), 7.27 ~ 7.22 (m, 3H), 7.17 (m, 7H), 1.67 (s, 6H)

Synthetic example  8: Preparation of Compound 2

Compound B (10g, 24.3mmol) 1.0eq, 9-bromoanthracene (9.37g, 36.45mmol) 1.5eq, dried tris (dibenzyldineacetone) dipalladium (0) (445mg, 0.486mmol) 0.02 eq, tri-tert-butylphosphine (295mg, 1.458mmol) 0.06eq Sodium tert-butoxide (11.7g, 121.5mmol) 5eq was added and filled with sufficient nitrogen to add 100ml of anhydrous toluene and stirred at reflux for 20 hours at 85 ℃ Let.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with dichloromethane and hexane, and the filtrate layer was separated by a column to obtain Compound 2 (11.74 g, 82%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.55 (q, 1H), 8.42 (q, 1H), 7.80 to 7.90 (m, 6H), 7.55 to 7.07 (m, 5H), 7.28 to 7.46 (m, 10H), 6.75 (d, 1H), 6.52-6.58 (m, 3H), 1.67 (s, 6H)

Synthetic example  9: Preparation of Compound 3

Compound A (10 g, 27.66 mmol) 1.0eq, 2-bromopyridine (6.56 g, 41.5 mmol) 1.5 eq, tris (dibenzyldineacetone) dipalladium (0) (507 mg, 0.553 mmol) 0.02 in a dried round flask eq, tri-tert-butylphosphine (336mg, 1.66mmol) 0.06eq sodium tert-butoxide (13.3g, 138.32mmol) 5eq was added and filled with nitrogen sufficiently, 100ml of anhydrous toluene was added and stirred under reflux at 85 ° C for 20 hours. Let.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane, and the filtrate layer was separated by a column to obtain compound 3 (9.96 g, 82%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.11 (q, 1H), 7.84 (q, 1H), 7.75 (q, 2H), 7.38-7.55 (m, 9H), 7.28 (m, 1H), 6.70 ~ 6.75 (m, 3H), 6.52-6.58 (m, 3H), 1.67 (s, 6H)

Synthetic example  10: Preparation of Compound 4

Compound A (10 g, 27.66 mmol) 1.0eq, 1-bromoisoquinoline (8.6 g, 41.5 mmol) 1.5eq, tris (dibenzyldineacetone) dipalladium (0) (507 mg, 0.553 mmol) in a dried round flask Add 0.02eq, tri-tert-butylphosphine (336mg, 1.66mmol), 0.06eq sodium tert-butoxide (13.3g, 138.32mmol) 5eq, fill with nitrogen sufficiently, add 100ml of anhydrous toluene, and reflux at 85 ℃ for 20 hours. Stir.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the resulting mixture was separated with dichloromethane and hexane, and the filtrate layer was separated by a column to obtain compound 4 (10.8 g, 80%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.28 (d, 1H), 8.17 (q, 1H), 7.84 (q, 1H), 7.75 (q, 2H), 7.28-7.7.6 (m, 12H), 6.99 (q, 1H), 6.75 (d, 1H), 6.52-6.58 (m, 3H), 1.67 (s, 6H)

Synthetic example  11: Preparation of Compound 5

Compound A (10 g, 27.66 mmol) 1.0 eq, N-bromo-N, N-diphenylbenzeneamine (13.6 g, 41.5 mmol) 1.5 eq, tris (dibenzyldineacetone) dipalladium (0) in a dried round flask ) (507mg, 0.553mmol) 0.02eq, tri-tert-butylphosphine (336mg, 1.66mmol) 0.06eq Sodium tert-butoxide (13.3g, 138.32mmol) 5eq was added and filled with nitrogen, 100ml of anhydrous toluene The mixture was stirred at reflux for 20 hours at 85 ° C.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane. The filtrate was separated by a column to obtain compound 5 (13.55 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 7.84 (q, 1H), 7.75 (m, 2H), 7.48 to 7.59 (m, 3H), 7.39 to 7.48 (m, 6H), 7.28 (m, 1H) , 7.92-7.22 (m, 6H), 6.76 (m, 1H), 6.52-6.68 (6H), 6.21 (d, 4H), 1.67 (s, 6H)

Synthetic example  12: Preparation of Compound 6

Compound C (9.3g 27.66mmol) 1.0eq, 1-bromonaphthalene (8.6g, 41.5mmol) 1.5eq, dried tris (dibenzyldineacetone) dipalladium (0) (507mg, 0.553mmol) 0.02 eq, tri-tert-butylphosphine (336mg, 1.66mmol) 0.06eq sodium tert-butoxide (13.3g, 138.32mmol) 5eq was added and filled with nitrogen sufficiently, 100ml of anhydrous toluene was added and stirred under reflux at 85 ° C for 20 hours. Let.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane. The filtrate layer was separated by a column to obtain compound 6 (10.32 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.10 (q, 1H), 8.3 (q, 1H), 7.40 to 7.55 (m, 7H), 7.08 to 7.30 (m, 10H), 6.48 to 6.60 (m, 4H), 6.20 (q, 1H)

Synthetic example  13: Preparation of Compound 7

Compound D (10g 27.66mmol) 1.0eq, 1-bromonaphthalene (8.6g, 41.5mmol) 1.5eq, dried tris (dibenzyldineacetone) dipalladium (0) (507mg, 0.553mmol) 0.02eq , Tri-tert-Butylphosphine (336mg, 1.66mmol) 0.06eq Sodium tert-butoxide (13.3g, 138.32mmol) 5eq was added and filled with sufficient nitrogen, 100ml of anhydrous toluene was added and refluxed at 85 ° C. for 20 hours. Let's do it.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane, and the filtrate layer was separated by a column to obtain compound 7 (10.95 g, 81%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.50 (d, 1H), 8.36 (m. 2H), 8.03 (m, 1H), 7.81 (m, 1H), 7.30-7.61 (m, 10H), 7.28 (m, 1H), 7.16 (m, 2H), 6.98 (q, 1H), 6.75 (d, 1H), 6.57 (m, 2H), 1.67 (s, 6H)

Synthetic example  14: Preparation of Compound 8

Compound E (10g, 18.74mmol) 1.0eq, 1-bromonaphthalene (5.82g, 28.11mmol) 1.5eq, dried tris (dibenzyldineacetone) dipalladium (0) (343mg, 0.375mmol) 0.02 eq, tri-tert-butylphosphine (227mg, 1.124mmol) 0.06eq Sodium tert-butoxide (9.0g, 93.7mmol) 5eq was added and filled with enough nitrogen to add 100ml of anhydrous toluene and stirred at reflux for 20 hours at 85 ℃ Let.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane, and the filtrate was separated by a column to obtain compound 8 (7.52 g, 83%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.44 (m, 4H), 8.32 (q, 4H), 7.79 (q, 6H), 7.50 ~ 7.64 (m, 8H), 7.11-7.26 (m, 7H) , 6.40-6.35 (m, 3H), 5.64 (d, 1H)

Synthetic example  15: Preparation of Compound 9

Compound F (10 g, 20.68 mmol) 1.0eq, N-bromo-N, N-diphenylbenzeneamine (10.06 g, 31.02 mmol) 1.5eq, tris (dibenzyldineacetone) dipalladium (0) in a dried round flask ) (378mg, 0.413mmol) 0.02eq, tri-tert-butylphosphine (250mg, 1.24mmol) 0.06eq, sodium tert-butoxide (9.94g, 103.4mmol) 5eq is added and filled with nitrogen sufficiently to 100ml of anhydrous toluene The mixture was stirred at reflux for 20 hours at 85 ° C.

After cooling to room temperature, distilled water was added to terminate the reaction and extracted with dichloromethane and distilled water, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtered organic layer was concentrated under reduced pressure, and the mixture was separated with a dichloromethane and hexane, and the filtrate was separated by a column to obtain compound 9 (11.27 g, 75%).

¹ H NMR (400 MHz, CDCl ₃ ): δ 7.74 (q, 2H), 7.65 (m, 2H), 7.40 to 7.51 (m, 4H), 7.35 to 7.44 (m, 6H), 7.23 (m, 1H) , 7.92-7.22 (m, 6H), 6.76 (m, 1H), 6.52-6.68 (6H), 6.21 (d, 4H), 1.67 (s, 6H)

Example  One: Organic field  Manufacture of light emitting device

A glass substrate coated with a film of ITO (indium tin oxide) having a thickness of 1500 Å was placed in secondary distilled water in which Fischer's detergent was dissolved, and ultrasonically cleaned. The ITO was washed for 30 minutes and then washed twice with distilled water and ultrasonically cleaned for 10 minutes. After the distilled water was washed, ultrasonic washing with a solvent of isopropyl alcohol, acetone and methanol was dried, and then transferred to a plasma cleaner. The substrate was cleaned for 5 minutes using an oxygen plasma and then transferred to a vacuum evaporator.

An amine-based ELM200 was thermally vacuum deposited to a thickness of 500 kPa on the prepared ITO transparent electrode to form a hole injection layer. After vacuum depositing Compound 1 (300 kPa) obtained in Synthesis Example 7 as a material for transporting holes thereon, an anthracene-based MADN was vacuum deposited to a thickness of 300 kPa as an emission layer, and an Alq3 compound was deposited to a thickness of 300 kPa as an electron transporting layer. After vacuum deposition, lithium fluoride (LiF) 7) and 1000Å thick aluminum were deposited to form a cathode.

In the above process, the deposition rate of the organic material was maintained at 1 Å / sec, the lithium fluoride was 0.2 Å / sec, and the aluminum was maintained at the deposition rate of 3-7 Å / sec.

Table 1 shows the characteristics of the organic electroluminescent device manufactured at the current density of 50 mA / cm ² , such as driving voltage, luminescence brightness, coloring coordinates, and luminous efficiency.

Example  2: Organic field  Manufacture of light emitting device

An organic electroluminescent device was manufactured in the same manner as in Example 1, except that Compound 5 obtained in Synthesis Example 11 was used instead of Compound 1 to transport the holes.

The characteristics of the organic electroluminescent device at a current density of 50 mA / cm ² , such as driving voltage, luminescence brightness, coloring coordinates, and luminous efficiency, were shown in Table 1.

Comparative example  One: Organic field  Manufacture of light emitting device

Example 1 except that N, N'-di (naphthalen-1-yl) -N, N'-diphenylbenzidine (NPB) represented by the following Chemical Formula 3 was used instead of Compound 1 as a material for transporting holes: In the same manner as in the organic EL device was manufactured.

(3)

Table 1 shows the characteristics of the driving voltage, the light emission luminance, the color coordinate, and the light emission efficiency at the current density of 50 mA / cm ² of the organic light emitting device manufactured above.

Example 1 Example 2 Comparative Example 1 The driving voltage (V) 6.57 6.95 7.45 Luminance Luminance (cd / m ² ) 5660 4860 4305 Color coordinates (0.14, 0.19) (0.14, 0.18) (0.14, 0.19) The luminous efficiency (cd / A) 11.3 10.4 9.3

Compared with the result of using NPB, which is a commercially available material, in the organic electroluminescent device, the result of using the tertiary aryl amine having an asymmetric structure represented by the formula (1) according to the present invention as a hole transporting material is the present invention. All of the organic light emitting diodes exhibited excellent IVL characteristics with significantly improved efficiency while lowering the driving voltage. As described above, according to the present invention, excellent mobility of holes and electrons is improved, and thus low-voltage, high-efficiency, high brightness, and long-life organic light emitting devices based on excellent hole transport and electron transport capabilities can be manufactured.

01 substrate
02 Anode
03 cathode
04 Hole injection layer
05 hole transport layer
06 Light emitting layer
07 Hole blocking layer
08 Electron transport layer
09 Electron injection layer

Claims (10)

Tertiary aryl amines represented by Formula 1:
Formula 1

Ar ₁ and Ar ₂ are the same or different, each selected from an arylene group of C4 ~ C25 and a heteroarylene group of C4 ~ C25,
A ₁ and a ₂ are the same or different, each selected from the group consisting of H, C 4 -C 25 aryl group, C 4 -C 25 heteroaryl group, amino group and substituted amino group,
Y is C or N,
When Y is N, a ₃ is a non-covalent electron pair, a ₄ is any one selected from the group consisting of H, an alkyl group of C 1 -C 13, an aryl group of C 4 -C 25, and a heteroaryl group of C 4 -C 25,
When Y is C, a ₃ and a ₄ are the same or different, and each selected from the group consisting of H, C 1 -C 13 alkyl group, C 4 -C 25 aryl group, and C 4 -C 25 heteroaryl group, or a <_3> and a <_4> are the structures connected with the ring of C4-C20.
The method of claim 1,
Ar ₁ and Ar ₂ of the formula (1) is a phenylene group (phenylene), naphthylene (naphthylene), anthracenylene group (anthracenylene), pyridylene group (pyridylene), quinolinylene group (quinolinylene) and isoquinolinyl Tertiary aryl amine, characterized in that any one selected from the group consisting of (isoquinolinylene).
The method of claim 1,
A ₁ and a ₂ in Formula 1 are H, phenyl group (phenyl), naphthyl group (naphthyl), anthracenyl group (anthracenyl), pyridyl group (pyridyl), quinolinyl group (quinolinyl), isoquinolinyl group (isoquinolinyl) ) And N, N-diphenylamino group (N, N-diphenylamino) tertiary aryl amine, characterized in that any one selected from the group consisting of.
The method of claim 1,
When Y in Formula 1 is N, a ₃ is a non-covalent electron pair, and a ₄ is H, a C1-C13 alkyl group, a phenyl group, a naphthyl group, anthracenyl group, and an pyridyl group. ), A quinolinyl group (quinolinyl) and isoquinolinyl group (isoquinolinyl) is any one selected from the group consisting of tertiary aryl amines.
The method of claim 1,
When Y in Formula 1 is C, a ₃ and a ₄ are the same or different, and each of H, C 1 to C 13, an alkyl group, a phenyl group, a naphthyl group, an anthracenyl group, and an pyridyl group (pyridyl), quinolinyl (quinolinyl) and isoquinolinyl (isoquinolinyl) tertiary aryl amine, characterized in that any one selected from the group consisting of.
The method of claim 1,
If Y is a C in the general formula 1, a ₃ and a ₄ is a structure attached to the ring, a ₃ and a ring connecting a ₄ to 3, characterized in that the aryl group of the C4 ~ C20 cycloalkyl group, or C4 ~ C20 Primary aryl amines.
The method of claim 1,
Tertiary aryl amine, characterized in that the a ₃ and a ₄ ring structure is represented by the following formula (2):
(2)

Ar ₁ and Ar ₂ are the same or different, each selected from an arylene group of C4 ~ C25 and a heteroarylene group of C4 ~ C25,
A ₁ and a ₂ are the same or different and are each selected from the group consisting of H, C 4 -C 25 aryl group, C 4 -C 25 heteroaryl group, amino group and substituted amino group.
8. The method according to any one of claims 1 to 7,
The tertiary aryl amines are flat panel displays, flat emitters, illuminators for surface emitting OLEDs for lighting, flexible emitters, copiers, printers, LCD backlights, meter light sources, display panels, organic electroluminescent devices (OLEDs), organic solar cells (OSCs) Tertiary aryl amine, characterized in that applied to any one selected from electronic paper (e-Paper), organophotoreceptor (OPC) and organic transistor (OTFT).
A first electrode, a second electrode and at least one organic layer between these electrodes, wherein at least one layer of the organic layer comprises the tertiary aryl amine according to any one of claims 1 to 7. An organic electroluminescent device characterized by.
The method of claim 9,
The organic material layer of the at least one layer comprises a light emitting layer, and further comprising at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer and an electron injection layer.

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