A compound and use thereof

Abstract

This invention relates to a compound and its applications, the compound having the structure shown in formula (I) or formula (II), wherein R1 is selected from H, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, and the heteroatom in the heteroaryl is selected from O or S; L is selected from single bond, substituted or unsubstituted C6-C6 The compound comprises one of the following: 0-aryl groups, substituted or unsubstituted C3-C60 heteroaryl groups; R is selected from H, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl; Ar is selected from one of the following: substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl. When applied to OLED devices, the compound of this invention can effectively improve device efficiency and reduce driving voltage, making it a high-performance electron transport material.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and in particular to a compound and its applications. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a type of device with a sandwich-like structure, consisting of positive and negative electrode layers and an organic functional material layer sandwiched between them. When a voltage is applied to the electrodes of an OLED device, positive charges are injected from the positive electrode and negative charges from the negative electrode. Under the influence of an electric field, the positive and negative charges migrate, meet, and recombine within the organic layer to emit light. Due to their advantages such as high brightness, fast response, wide viewing angle, simple manufacturing process, and flexibility, OLED devices have attracted significant attention in the fields of new display and lighting technologies. Currently, this technology is widely used in display panels for new lighting fixtures, smartphones, and tablets, and its application is expected to expand further into large-size display products such as televisions. It is a rapidly developing and technologically demanding new display technology.

[0003] As OLED technology continues to advance in both lighting and display fields, research into its core materials is receiving increasing attention. This is because a high-efficiency, long-life OLED device is typically the result of an optimized combination of device structure and various organic materials. This presents chemists with both significant opportunities and challenges in designing and developing functionalized materials with diverse structures. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as luminescent host materials and luminescent guest materials (dyes), etc.

[0004] To fabricate OLED devices with lower driving voltages, better luminous efficiency, and longer lifespans, and to continuously improve the performance of OLED devices, it is necessary not only to innovate the structure and fabrication process of OLED devices, but also to continuously research and innovate the optoelectronic functional materials in OLED devices to prepare functional materials with higher performance. Based on this, the OLED materials community has been committed to developing new organic electroluminescent materials to achieve devices with low start-up voltages, high luminous efficiency, and better lifespans.

[0005] To further meet the ever-increasing demands for the photoelectric performance of OLED devices and the energy-saving requirements of mobile electronic devices, it is necessary to continuously develop new and efficient OLED materials. Among these, developing new electron transport materials with high electron injection capability and high mobility is of great significance. Summary of the Invention

[0006] The purpose of this invention is to provide a compound having high electron injection capability and high electron mobility.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The present invention provides a compound having the structure shown in formula (I) or formula (II);

[0009]

[0010] In formulas (I) and (II), R1 is selected from H, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl, and the heteroatom in the heteroaryl is selected from O or S;

[0011] The R represents a single substituent to the most permissible substituent, and each is independently selected from H, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, and when there are multiple Rs, adjacent Rs can be fused together.

[0012] Preferably, R is selected from one of substituted or unsubstituted C6-C30 aryl groups or substituted or unsubstituted C3-C30 heteroaryl groups;

[0013] The L is selected from one of single-bonded, substituted or unsubstituted C6-C60 arylene, or substituted or unsubstituted C3-C60 heteroarylene; preferably, L is selected from one of single-bonded, substituted or unsubstituted C6-C30 arylene, or substituted or unsubstituted C3-C30 heteroarylene.

[0014] The Ar is selected from one of substituted or unsubstituted C6-C60 aryl groups and substituted or unsubstituted C3-C60 heteroaryl groups;

[0015] Preferably, Ar is selected from one of substituted or unsubstituted C6-C30 aryl groups or substituted or unsubstituted C3-C30 heteroaryl groups;

[0016] When the above-mentioned groups contain substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, carbonyl, C1-C12 chain alkyl, C3-C12 cycloalkyl, C2-C10 alkenyl, C1-C10 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl or fused-ring aryl, and C3-C30 monocyclic heteroaryl or fused-ring heteroaryl.

[0017] Furthermore, the compounds of the present invention have the structures shown in formulas (1) to (10):

[0018]

[0019] In equations (1) to (10), the definitions of R1, Ar and L are the same as those in equations (I) and (II);

[0020] The R2-R 10 They may be the same or different, and each is independently selected from one of H, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, and R2-R 10 Two adjacent elements can be fused together.

[0021] Furthermore, in formulas (I), (II), and (1) to (10) of this invention, Ar has the structure of formula A:

[0022]

[0023] In Formula A, Y1-Y6 are selected from CR' or N, and R' is independently selected from one of hydrogen, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, halogen, cyano, alkenyl, alkynyl, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl. Two adjacent R' can be fused together to form a ring.

[0024] In a further preferred embodiment, in formulas (I), (II), and (1) to (10) of the present invention, the Ar is selected from the following structural formulas, whether substituted or unsubstituted:

[0025]

[0026] When the above structural formula contains substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, carbonyl, C1-C12 chain alkyl, C3-C12 cycloalkyl, C2-C10 alkenyl, C1-C10 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl or fused-ring aryl, and C3-C30 monocyclic heteroaryl or fused-ring heteroaryl.

[0027] Furthermore, the aforementioned R2-R is preferred. 10R and R' are each independently selected from hydrogen, deuterium, or the following substituents: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracene, benzo[a]anthrayl, phenanthrene, benzo[a]phenanthrene, pyrene, pyryl, peryl, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, amphylphenyl, terphenyl, triphenyl, tetraphenyl, fluorene , spirodifluorenyl, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis or trans indofluorenyl, trimerinyl, isotrimericininyl, spirotrimericininyl, spiroisotrimericininyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thiopheneyl, benzothiopheneyl, isobenzothiopheneyl, dibenzothiopheneyl, pyrroleyl, isoindoleyl, carbazoleyl, indocarbazoleyl, pyridinyl, quinolinyl, isoquinolinyl, acridineyl, phenanthridineyl, benzo-5,6-quinolinyl, benzo-6,7-quinolinyl, benzo-7,8-quinolinyl, pyrazolyl, indazoleyl, imidazolyl, benzimidazolyl, naphzimidazolyl, phenanthrenemidazolyl, Pyridinium imidazolyl, pyrazinium imidazolyl, quinoxalinium imidazolyl, oxazolyl, benzoxoxazolyl, naphthoxoxazolyl, anthraquinoxazolyl, phenanthoxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthrayl, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenthiazinyl, naphridinyl, azacarbazolyl, benzocarbazolyl, phenanthrolinel, 1 One of 2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purine, pteridine, indazinyl, benzothiadiazolyl, or a combination of the above two groups.

[0028] Furthermore, the compounds described in the general formula of the present invention can preferably be specific structural compounds shown in C1-C83 below, these compounds are only representative:

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] A second objective of this invention is to provide an application of the compound described in one objective, wherein the compound is used in organic electronic devices.

[0035] Preferably, the organic electronic device includes an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin-film transistor, an organic field-effect transistor, an organic thin-film solar cell, an information tag, an electronic artificial skin sheet, a sheet-type scanner, or electronic paper, with organic electroluminescent devices being the most preferred.

[0036] Preferably, the compound is used as an electron transport material in the organic electroluminescent device.

[0037] The compounds of the present invention have high electron affinity and thus a strong ability to accept electrons, making them suitable for use as electron transport materials, but not limited thereto.

[0038] The third objective of this invention is to provide an organic electroluminescent device, comprising a first electrode, a second electrode, and one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer contains a general formula compound of this invention as shown in any of the above formulas (I), (II), (1)-(10), or contains compounds shown in the various specific structural formulas as described above.

[0039] OLED devices prepared using the compounds of this invention have low start-up voltage, high luminous efficiency, and better lifespan, which can meet the current requirements of panel manufacturers for high-performance materials.

[0040] Specifically, one embodiment of the present invention provides an organic electroluminescent device, including a substrate, and an anode layer, a plurality of light-emitting functional layers and a cathode layer sequentially formed on the substrate; the light-emitting functional layers include a hole injection layer, a hole transport layer, a light-emitting layer and an electron transport layer, wherein the hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and the light-emitting layer is located between the hole transport layer and the electron transport layer; wherein the electron transport layer contains a compound of the general formula of the present invention shown in any of the above formulas (I), (II), and (1)-(10).

[0041] More specifically, organic electroluminescent devices will be described in detail.

[0042] An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0043] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0044] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), and zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as the cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), and magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0045] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0046] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0047] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives as shown in HT-1 to HT-34 below; or any combination thereof.

[0048]

[0049]

[0050]

[0051] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-34 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-34 doped with one or more compounds of HI-1 to HI-3 described below.

[0052]

[0053] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0054] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0055] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0056]

[0057]

[0058] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of BFD-1 to BFD-12 listed below.

[0059]

[0060] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0061]

[0062]

[0063]

[0064] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0065]

[0066]

[0067]

[0068] Where D represents deuterium.

[0069] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0070]

[0071]

[0072] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0073]

[0074]

[0075] The organic electroluminescent device of the present invention includes an electron transport region between a light-emitting layer and a cathode. The electron transport region can be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0076] The electron transport region can also be formed by applying the compound of the present invention to a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL). Of course, the material of the electron transport region can also be combined with one or more of ET-1 to ET-57 listed below.

[0077]

[0078]

[0079]

[0080] The device may also include an electron injection layer located between the electron transport layer and the cathode, wherein the electron injection layer material includes, but is not limited to, one or more combinations of the following:

[0081] Liq, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0082] The specific reasons for the superior performance of the compounds of the present invention are not yet clear, but it is speculated that the reasons may be as follows:

[0083] The general formula compounds of this invention use the electron-deficient, highly conjugated structure of 9,10-benzophenanthridine as the parent core, with single-bonded Ar electron-deficient groups. Compared with the commonly used single oxazole, thiazole, imidazole, triazole, or triazine structures in the prior art, the compounds of this invention exhibit relatively stronger electron-deficient properties, thus facilitating electron injection. Simultaneously, the presence of highly conjugated electron-deficient groups in the compounds of this invention gives the molecules good planar conjugation, thereby improving electron mobility. These two structural characteristics enable the molecules as a whole to exhibit excellent electron injection and migration performance. Therefore, when the compounds of this invention are used as electron transport layer materials in organic electroluminescent devices, they can effectively improve the electron injection and migration efficiency in the device, thereby ensuring that the device achieves excellent results with high luminous efficiency and low start-up voltage.

[0084] In addition, the preparation process of the compounds of the present invention is simple and easy to implement, the raw materials are readily available, and it is suitable for mass production scale-up. Detailed Implementation

[0085] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0086] The synthetic route for the compounds represented by the general formula of this invention is as follows:

[0087]

[0088] The first step involves the amine-aldehyde condensation of substituted benzaldehyde or benzophenone with O-methylhydroxylamine hydrochloride in a solution of sodium borohydride in tetrahydrofuran under the catalysis of glacial acetic acid to obtain intermediate M1 of methoxyimine. The second step involves the addition reaction of intermediate M1 with substituted 1,4-dihydronaphthalene-1,4-imine-9-carboxylic acid tert-butyl ester under the catalysis of bis(antimony hexafluoride)cyclopentadienyltri(acetonitrile)rhodium(III) to obtain intermediate M2. The third step involves the ring closure of M2 after heating in 6 mol / L hydrochloric acid for 6 hours to obtain 9,10-benzo-11,12-dihydrophenanthridine. The fourth step involves the dehydrogenation of dihydro-5,6-dicyanobenzoquinone to obtain the target product.

[0089] All the chemical reagents used in the following synthesis examples, such as acetonitrile, ethyl acetate, sodium sulfate, tetrahydrofuran, dichloromethane, N,N-dimethylformamide, 1,4-dioxane, potassium carbonate, and potassium acetate, were purchased from Shanghai Titan Technology Co., Ltd. and Xilong Chemical Co., Ltd. The mass spectrometer used to determine the following compounds was a ZAB-HS type mass spectrometer (manufactured by Micromass, UK).

[0090] Synthesis example 1:

[0091] Compound C3 Synthesis

[0092]

[0093] (1) Preparation of compound 1-1

[0094] 26 g (100 mmol) of 4-bromophenyl-phenyl dimethyl ketone and O-methylhydroxylamine hydrochloride were added to a 500 mL flask containing 200 mL of tetrahydrofuran. 2 mL of glacial acetic acid was added with stirring at room temperature, followed by the slow addition of sodium borohydride (15.2 g, 400 mmol) in portions. After the addition was complete, the reaction mixture was refluxed at 80 °C with stirring for 4 hours. TLC monitoring showed that the reaction was complete. After cooling the reaction solution to room temperature, the remaining sodium borohydride was quenched with water, and the mixture was extracted with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate and purified by column chromatography to obtain compound 1-1 (25.2 g, 87% yield).

[0095] (2) Preparation of compounds 1-2

[0096] Compound 1-1 (25 g, 87 mmol), tert-butyl 1,4-dihydronaphthalene-1,4-imin-9-carboxylic acid (21.1 g, 87 mmol), and 300 mL of 1,2-dichloroethane were added to a 1 L flask. After purging with nitrogen, di(antimony hexafluoride)cyclopentadienyltri(acetonitrile)rhodium(III) (1.36 g, 1.7 mmol) was added, followed by purging with nitrogen four times. The mixture was stirred at 80 °C for 15 hours, and the reaction endpoint was monitored by TLC. The solvent was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 1-2 (38.3 g, 72% yield).

[0097] (3) Preparation of compounds 1-3

[0098] Compounds 1-2 (38 g, 71.4 mmol) were slowly added to 200 mL (6 mol / L) of concentrated hydrochloric acid under stirring at room temperature. After the addition was complete, the mixture was stirred at 80 °C for 6 hours, resulting in the precipitation of a large amount of solid. The reaction was monitored by TLC until it was complete. Dichloromethane was added for extraction and separation. The organic phase was washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compounds 1-3 (24.7 g, 90% yield).

[0099] (4) Preparation of compounds 1-4

[0100] Compounds 1-3 (24.5 g, 63.6 mmol) and 9,10-benzo-11,12-dihydrophenanthrene (14.4 g, 63.6 mmol) were added to 200 mL of toluene and stirred at 80 °C for 4 hours. The reaction was stopped by TLC. The solvent was removed by rotary evaporation, and the mixture was purified by column chromatography to give compounds 1-4 (21 g, 86% yield).

[0101] (5) Preparation of compounds 1-5

[0102] Compounds 1-4 (20 g, 52.2 mmol), pinacol diboronate (19.9 g, 78.3 mmol), and potassium acetate (10.2 g, 104.4 mmol) were added to a 1 L flask containing 300 mL of 1,4-dioxane. After purging with nitrogen at room temperature with stirring, palladium acetate (0.35 g, 1.38 mmol) and 2-bicyclohexylphosphine-2',6'-dimethoxybiphenyl (1.13 g, 2.76 mmol) were added. After the addition was complete, nitrogen was purged four times, and the mixture was stirred and refluxed for 12 hours. The reaction endpoint was monitored by TLC. 1,4-dioxane was removed by rotary evaporation. The mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compounds 1-5 (21 g, 94% yield).

[0103] (4) Preparation of compound C3

[0104] Compounds 1-5 (15 g, 34.8 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (9.8 g, 34.8 mmol), potassium carbonate (9.6 g, 70 mmol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (256 mg, 0.35 mmol) were added to a flask containing 200 mL tetrahydrofuran and 50 mL water. The mixture was purged with nitrogen and heated under reflux for 4 hours. TLC showed that the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to give compound C3 (15.4 g, 83% yield). Calculated molecular weight: 536.20, measured C / Z: 536.2.

[0105] Synthesis example 2:

[0106] Synthesis of compound C15

[0107]

[0108] (1) Preparation of compound 2-1

[0109] 36.6 g (100 mmol) of 4-bromophenyl-1-dibenzofuran dimethyl ketone and O-methylhydroxylamine hydrochloride were added to a 500 mL flask containing 200 mL of tetrahydrofuran. 2 mL of glacial acetic acid was added with stirring at room temperature, followed by the slow addition of sodium borohydride (15.2 g, 400 mmol) in portions. After the addition was complete, the reaction mixture was refluxed at 80 °C with stirring for 4 hours. TLC monitoring showed that the reaction was complete. After cooling the reaction solution to room temperature, the remaining sodium borohydride was quenched with water, and the mixture was extracted with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate and purified by column chromatography to obtain compound 2-1 (34.3 g, 87% yield).

[0110] (2) Preparation of compound 2-2

[0111] Compound 2-1 (34 g, 87 mmol), tert-butyl 1,4-dihydronaphthalene-1,4-imin-9-carboxylic acid (21.1 g, 87 mmol), and 300 mL of 1,2-dichloroethane were added to a 1 L flask. After purging with nitrogen, di(antimony hexafluoride)cyclopentadienyltri(acetonitrile)rhodium(III) (1.36 g, 1.7 mmol) was added, followed by purging with nitrogen four times. The mixture was stirred at 80 °C for 15 hours, and the reaction endpoint was monitored by TLC. The solvent was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 2-2 (55.7 g, 72% yield).

[0112] (3) Preparation of compounds 2-3

[0113] Compound 2-2 (55.5 g, 71.4 mmol) was slowly added to 200 mL (6 mol / L) of concentrated hydrochloric acid under stirring at room temperature. After the addition was complete, the mixture was stirred at 80 °C for 6 hours, resulting in the precipitation of a large amount of solid. The reaction was monitored by TLC until it was complete. Dichloromethane was added for extraction and separation. The organic phase was washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compound 2-3 (31.6 g, 90% yield).

[0114] (4) Preparation of compounds 2-4

[0115] Compound 2-3 (31 g, 63.6 mmol) and 9,10-benzo-11,12-dihydrophenanthrene (14.4 g, 63.6 mmol) were added to 200 mL of toluene and stirred at 80 °C for 4 hours. The reaction was stopped by TLC. The solvent was removed by rotary evaporation, and the product was purified by column chromatography to give compound 2-4 (39.3 g, 86% yield).

[0116] (5) Preparation of compound C15

[0117] Compound 2-4 (15 g, 30.7 mmol), 2-(4-pinacolborylphenyl)-4,6-diphenyl-1,3,5-triazine (13.4 g, 30.7 mmol), potassium carbonate (8.5 g, 61.4 mmol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (224 mg, 0.31 mmol) were added to a flask containing 200 mL toluene, 40 mL ethanol, and 40 mL water. The mixture was purged with nitrogen and refluxed under nitrogen atmosphere for 6 hours. TLC showed that the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to give compound C15 (18.3 g, yield 83%). Calculated molecular weight: 718.22, measured C / Z: 718.2.

[0118] Synthesis example 3:

[0119] Synthesis of compound C31

[0120]

[0121] 1) Preparation of compound 3-1

[0122] 50 g (256 mmol, 1.0 eq) of 2,4-dichloroquinazoline was added to a 1 L single-necked flask, followed by 400 mL of dichloromethane. The mixture was cooled to 0 °C in an ice bath, and then 64 g (632 mmol, 3.0 eq) of triethylamine was added. The mixture was stirred until the reaction solution became clear. 18.6 g (316 mmol, 1.5 eq) of hydrazine hydrate was added dropwise in an ice bath. During the reaction, a solid gradually precipitated out. The mixture was stirred for 3 hours, and the reaction was monitored by TLC until the starting material disappeared. 4.0 L of water was added, and the mixture was stirred for another hour. The mixture was filtered, dried, and compound 3-1 (33 g, yield: 81%) was obtained.

[0123] (2) Preparation of compound 3-2

[0124] 33 g (170 mmol, 1.0 eq) of compound 3-1, 19.8 g (187 mmol, 1.1 eq) of benzaldehyde, and 500 mL of ethanol were added to a 1.0 L single-necked flask. The mixture was stirred until the solution became clear, and then stirred for another 30 minutes. The reaction proceeded as monitored by TLC. 60 g (187 mmol, 1.1 eq) of iodophenyldiacetic acid was added in portions (the temperature was kept below 20 °C during addition). After the addition was complete, the mixture was stirred overnight. A solid gradually precipitated out. After the reaction was completed as monitored by TLC, the mixture was filtered. The filter cake was washed with ethanol until the filtrate was a colorless clear liquid. The filtrate was then washed 2 to 3 times with PE and dried to obtain compound 3-2 (39 g, yield: 82%).

[0125] (3) Preparation of compound C31

[0126] Compounds 1-5 (15 g, 34.8 mmol), compounds 3-2 (9.7 g, 34.8 mmol), potassium carbonate (9.6 g, 70 mmol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (256 mg, 0.35 mmol) were added to a flask containing 200 mL tetrahydrofuran and 50 mL water. The mixture was purged with nitrogen and refluxed under nitrogen atmosphere for 8 hours. TLC showed complete reaction. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to give compound C31 (15.4 g, 84% yield). Calculated molecular weight: 549.20, measured C / Z: 549.2.

[0127] Synthesis example 4:

[0128] Synthesis of compound C32

[0129]

[0130] (1) Preparation of compound 4-1

[0131] 2-Amino-4,6-diphenylpyrazine (24.7 g, 100 mmol) was dissolved in 250 mL of dioxane and added to a 500 mL three-necked flask. While maintaining the temperature no higher than 15 °C, ethoxycarbonyl isothiocyanate (15.8 g, 120 mmol) was gradually added dropwise, and the mixture was stirred at room temperature for 4 hours. The reaction was confirmed to be complete by TLC. The dioxane was concentrated, washed with ethanol, filtered, and purified by column chromatography to obtain compound 4-1 (29.1 g, yield 77%).

[0132] (2) Preparation of compound 4-2

[0133] Hydroxylamine hydrochloride (19.2 g, 288 mmol) was added to a 500 mL three-necked flask, followed by 150 mL of ethanol and 150 mL of methanol. Triethylamine (19.2 g, 288 mmol) was then added in portions, and the mixture was stirred at room temperature for one hour. Compound 4-1 (24 g, 64 mmol) was then added, and the mixture was heated to reflux and reacted for approximately 4 hours. The reaction was monitored by TLC until complete, and the mixture was cooled to room temperature. The mixture was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound 4-2 (15.2 g, 93%).

[0134] (3) Preparation of compound 4-3

[0135] CuBr2 (23.4 g, 106 mmol) and acetonitrile (MeCN) 200 mL were added to a 500 mL single-necked flask. Then, tert-butyl nitrite (11 g, 106 mmol) was slowly added dropwise, and the mixture was heated and stirred at 50 °C for one hour. Compound 4-2 (15.2 g, 53 mmol) was then added in portions, and the mixture was stirred at 60 °C. After 3 hours of reaction, TLC showed that compound 4-2 had reacted completely. After cooling, the reaction solution was poured into 1 L of water, and a large amount of yellow-green solid precipitated. The solid was filtered, washed with ethanol, dried, extracted with DCM, and separated. The organic phase was dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 4-3 (15.4 g, 83% yield).

[0136] (4) Preparation of compound C32

[0137] Compounds 4-3 (15 g, 42.8 mmol), compounds 1-5 (18.4 g, 42.8 mmol), potassium carbonate (11.8 g, 85.6 mmol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (316 mg, 0.43 mmol) were added to a flask containing 200 mL tetrahydrofuran and 50 mL water. The mixture was purged with nitrogen and heated under reflux for 5 hours. TLC showed that the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to give compound C32 (20.4 g, yield 83%). Calculated molecular weight: 575.21, measured C / Z: 575.2.

[0138] Synthesis example 5:

[0139] Synthesis of compound C51

[0140]

[0141] (1) Preparation of compound 5-1

[0142] Phenyl-1-dibenzofuranyl dimethyl ketone (28.8 g, 100 mmol) and O-methylhydroxylamine hydrochloride were added to a 500 mL flask containing 200 mL of tetrahydrofuran. 2 mL of glacial acetic acid was added with stirring at room temperature, followed by the slow addition of sodium borohydride (15.2 g, 400 mmol) in portions. After the addition was complete, the reaction mixture was refluxed at 80 °C with stirring for 3 hours. TLC monitoring showed that the reaction was complete. After cooling the reaction solution to room temperature, the remaining sodium borohydride was quenched with water, and the mixture was extracted with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate and purified by column chromatography to obtain compound 5-1 (29.5 g, 93% yield).

[0143] (2) Preparation of compound 5-2

[0144] Compound 5-1 (29 g, 91.5 mmol), 7-bromo-1,4-dihydronaphthyl-1,4-imin-9-carboxylic acid tert-butyl ester (29.3 g, 91.5 mmol), and 300 mL of 1,2-dichloroethane were added to a 1 L flask. After purging with nitrogen, di(antimony hexafluoride)cyclopentadienyltri(acetonitrile)rhodium(III) (2.16 g, 2.7 mmol) was added, followed by purging with nitrogen four times. The mixture was stirred at 80 °C for 15 hours, and the reaction endpoint was monitored by TLC. The solvent was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 5-2 (44.3 g, 76% yield).

[0145] (3) Preparation of compound 5-3

[0146] Compound 5-2 (44 g, 70.0 mmol) was slowly added to 200 mL (6 mol / L) of concentrated hydrochloric acid under stirring at room temperature. After the addition was complete, the mixture was stirred at 80 °C for 6 hours, resulting in the precipitation of a large amount of solid. The reaction was monitored by TLC until it was complete. Dichloromethane was added for extraction and separation. The organic phase was washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compound 5-3 (32 g, 93% yield).

[0147] (4) Preparation of compound 5-4

[0148] Compound 5-3 (30 g, 61.3 mmol) and 9,10-benzo-11,12-dihydrophenanthrene (13.9 g, 61.3 mmol) were added to 200 mL of toluene and stirred at 80 °C for 4 hours. The reaction was stopped by TLC. The solvent was removed by rotary evaporation, and the mixture was purified by column chromatography to give compound 5-4 (25.3 g, 85% yield).

[0149] (5) Preparation of compound C51

[0150] Compound 5-4 (15 g, 30.7 mmol), 2-(4-pinacolborylphenyl)-4,6-diphenyl-1,3,5-triazine (13.4 g, 30.7 mmol), potassium carbonate (8.5 g, 61.4 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (224 mg, 0.31 mmol) were added to a flask containing 200 mL toluene, 40 mL ethanol, and 40 mL water. The mixture was purged with nitrogen and refluxed under nitrogen atmosphere for 5 hours. TLC showed complete reaction. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to give compound C51 (19.1 g, 86% yield). Calculated molecular weight: 718.22; Measured C / Z: 718.2.

[0151] Synthesis example 6:

[0152] Synthesis of compound C62

[0153]

[0154] (1) Preparation of compound 6-1

[0155] Benzaldehyde (10.6 g, 100 mmol) and O-methylhydroxylamine hydrochloride were added to a 500 mL flask containing 200 mL of tetrahydrofuran. 2 mL of glacial acetic acid was added with stirring at room temperature, followed by the slow addition of sodium borohydride (15.2 g, 400 mmol) in portions. After the addition was complete, the reaction mixture was stirred at room temperature for 2 hours, and TLC monitoring showed that the reaction was complete. The reaction solution was cooled to room temperature, and the remaining sodium borohydride was quenched with water. The mixture was then extracted with dichloromethane, and the organic phases were combined, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compound 6-1 (10.9 g, 81% yield).

[0156] (2) Preparation of compound 6-2

[0157] Compound 6-1 (10 g, 74 mmol), 7-bromo-1,4-dihydronaphthyl-1,4-imin-9-carboxylic acid tert-butyl ester (23.7 g, 74 mmol), and 300 mL of 1,2-dichloroethane were added to a 1 L flask. After purging with nitrogen, di(antimony hexafluoride)cyclopentadienyltri(acetonitrile)rhodium(III) (1.76 g, 2.2 mmol) was added, followed by purging with nitrogen four times. The mixture was stirred at 80 °C for 15 hours, and the reaction endpoint was monitored by TLC. The solvent was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 6-2 (29 g, 86% yield).

[0158] (3) Preparation of compound 6-3

[0159] Compound 6-2 (28 g, 61.4 mmol) was slowly added to 200 mL (6 mol / L) of concentrated hydrochloric acid with stirring at room temperature. After the addition was complete, the mixture was stirred at 80 °C for 6 hours, resulting in the precipitation of a large amount of solid. The reaction was monitored by TLC until it was complete. Dichloromethane was added for extraction and separation. The organic phase was washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compound 6-3 (17.3 g, 91% yield).

[0160] (4) Preparation of compound 6-4

[0161] Compound 6-3 (17 g, 55 mmol) and 9,10-benzo-11,12-dihydrophenanthridine (12.5 g, 55 mmol) were added to 200 mL of toluene and stirred at 80 °C for 4 hours. The reaction was stopped by TLC. The solvent was removed by rotary evaporation and purified by column chromatography to give compound 6-4 (14.7 g, 87% yield).

[0162] (5) Preparation of compound C62

[0163] Compound 6-4 (10 g, 32.5 mmol), 2-(4-pinacolborylphenyl)-4,6-diphenyl-1,3,5-triazine (14.2 g, 32.5 mmol), potassium carbonate (8.7 g, 63 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (241 mg, 0.33 mmol) were added to a flask containing 200 mL toluene, 40 mL ethanol, and 40 mL water. The mixture was purged with nitrogen and refluxed under nitrogen atmosphere for 4 hours. TLC showed complete reaction. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to give compound C62 (15.3 g, 88% yield). Calculated molecular weight: 536.20, Measured C / Z: 536.2.

[0164] Synthesis of compound D1

[0165]

[0166] (1) Preparation of compound 1A

[0167] Compound 9,10-benzo-2-bromophenanthrene (30 g, 100 mmol), pinacol diboronate (30.2 g, 120 mmol), and potassium acetate (19.6 g, 200 mmol) were added to a 1 L flask containing 300 mL of N,N-dimethylformamide. After purging with nitrogen at room temperature with stirring, Pd(dppf)Cl2 (0.71 g, 1.00 mmol) was added. Nitrogen was purged four times after the addition was complete, and the mixture was stirred and refluxed for 12 hours. The reaction endpoint was monitored by TLC. The solvent was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 1A (32 g, 90% yield).

[0168] (2) Comparison of the synthesis of compound D1

[0169] Compound 1A (20 g, 56.3 mmol) and compound 1B (33.5 g, 56.3 mmol) were added to a 1 L flask containing 300 mL tetrahydrofuran and 80 mL water. After purging with nitrogen under stirring at room temperature, tetra(triphenylphosphine)palladium (2.0 g, 1.7 mmol) and sodium hydroxide (7.2 g, 179 mmol) were added. Nitrogen was purged four times after the addition was complete, and the mixture was stirred and refluxed for 12 hours. The reaction endpoint was monitored by TLC. The solvent was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain the control compound D1 (25 g, 69% yield).

[0170] Device Example 1

[0171] This embodiment of the device provides a method for fabricating an organic electroluminescent device, as detailed below:

[0172] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0173] The glass substrate with the anode was placed in a vacuum chamber and evacuated until the pressure was less than 10. -5 Pa, hole injection material HI-3 is vacuum-deposited on the above-mentioned anode layer as a hole injection layer, the deposition rate is 0.1 nm / s, and the total film thickness is 10 nm.

[0174] HT-4 was vacuum-deposited on top of the hole injection layer as the first hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 40 nm.

[0175] HT-14 was vacuum-deposited on top of the first hole transport layer as the second hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 10 nm.

[0176] The light-emitting layer of the device is vacuum-deposited on the second hole transport layer. The light-emitting layer includes a host material and a dye material. Using a multi-source co-evaporation method, the evaporation rate of the host material BFH-4 is adjusted to 0.1 nm / s, the evaporation rate of the dye BFD-6 is set to 5%, and the total evaporation film thickness is 20 nm.

[0177] ET-17 was vacuum-deposited on top of the light-emitting layer as a hole-blocking layer for the device at a deposition rate of 0.1 nm / s and a total film thickness of 5 nm.

[0178] An electron transport layer was deposited on top of the hole blocking layer using a multi-source co-evaporation method. The evaporation rate of compound C3 was adjusted to 0.1 nm / s and set to be 100% of the evaporation rate of ET-57. The total film thickness was 23 nm.

[0179] A 1 nm thick LiF layer was vacuum-deposited on the electron transport layer (ETL) as an electron injection layer, and an 80 nm thick Al layer was used as the cathode of the device.

[0180] The only difference between Device Examples 2-6 and Device Example 1 is that the compound C3 used in the electron transport layer of the present invention is replaced with other specific compounds of the present invention, as detailed in Table 1.

[0181] Device Comparison Example 1

[0182] The difference from Device Example 1 is that the compound C3 of the present invention used in the electron transport layer is replaced with the prior art compound D1.

[0183] Performance testing:

[0184] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in Examples 1-6 and Comparative Example 1 were measured using a Photo Research PR 750 radiometer, an ST-86LA luminance meter (Beijing Normal University Optoelectronic Instrument Factory), and a Keithley 4200 testing system. Specifically, the voltage was increased at a rate of 0.1V per second, and the driving voltage and current efficiency were measured when the brightness of the organic electroluminescent device reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency.

[0185] The performance test results are shown in Table 1.

[0186] Table 1:

[0187]

[0188] As shown in Table 1, when the material schemes and fabrication processes of other functional layers in the organic electroluminescent device structure are exactly the same, compared with the comparative examples, the organic electroluminescent devices provided in Examples 1-6 of the present invention have higher current efficiency and lower driving voltage. In Examples 1-6, the current efficiency of the device is 7.42-7.85 cd / A and the driving voltage of the device is 4.19-4.48 V.

[0189] The parent core of the compound of this invention is a 9,10-benzophenanthridine electron-deficient large conjugated structure. The Ar electron-deficient group is connected to the parent core by a single bond, which gives the entire compound high electron injection and migration performance, thereby giving the device high current efficiency and low driving voltage.

[0190] By comparing Examples 1 and 2 with Comparative Example D1, it can be seen that the voltage is lower and the current efficiency is higher. This is because when the R1 substituent is an electron-donating group such as phenyl and benzothiophene, the overall electron cloud density of the molecular structure is higher, and the overall device has stronger electron transport and injection capabilities.

[0191] The experimental data above show that the novel organic material of this invention, as an electron transport material for organic electroluminescent devices, is a high-performance organic light-emitting functional material with broad application prospects.

[0192] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A compound of a general formula having the structure shown in formula (I) or formula (II); In formulas (I) and (II), R1 is selected from one of C6~C60 aryl and C3~C60 heteroaryl, and the heteroatom in the heteroaryl is selected from O or S; The R is selected from H; The L is selected from one of the single-bonded, C6~C30 aryl groups; The Ar is selected from the following structural formulas, whether substituted or unsubstituted: When the above structural formula contains substituents, the substituents are selected from one of C1~C12 chain alkyl groups and C6~C30 aryl groups.

2. The compound according to claim 1, wherein the compound has the structure shown in formulas (1) to (10): In equations (1) to (10), the definitions of R1, Ar and L are the same as those in equations (I) and (II); The R2-R 10 Selected from H.

3. A compound having the structure shown below: 。 4. The use of the compound according to any one of claims 1-3, wherein the use is as a functional material in an organic electronic device selected from optical sensors, solar cells, lighting elements, organic thin-film transistors, organic field-effect transistors, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper.

5. The compound of any one of claims 1-3 is used as an electron transport material in an organic electroluminescent device.

6. An organic electroluminescent device, comprising a first electrode, a second electrode, and one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer includes a hole transport region, a light-emitting layer, and an electron transport region, wherein the hole transport region is formed on the anode layer, the cathode layer is formed on the electron transport region, and the light-emitting layer is located between the hole transport region and the electron transport region; wherein... The electron transport region includes an electron transport layer, which contains any one of the compounds described in claims 1-3.

Images