阅读说明：本技术 一种有机光电材料及其制备方法和应用 (Organic photoelectric material and preparation method and application thereof ) 是由 俞云海 谭奇 张晓龙 于 2019-04-22 设计创作，主要内容包括：本发明提供一种有机光电材料,所述有机光电材料具有如式I所示结构；本发明提供的有机光电材料中含有取代丁二烯的骨架结构,其中的两个双键形成共轭体系,使材料的热稳定性提高,进而提升了有机光电材料在加工过程中的成膜性能；分子中的交叉共轭结构和取代基中的吸电子基团共同作用,使分子具有较强的还原电位,从而辅助空穴传输层进行高效的空穴注入。本发明提供的有机光电材料作为OLED器件的空穴注入层客体材料,可以有效增加电荷注入,降低OLED器件的驱动电压,提高器件的使用寿命和整体效率。(The invention provides an organic photoelectric material, which has a structure shown in a formula I; the organic photoelectric material provided by the invention contains a skeleton structure of substituted butadiene, wherein two double bonds form a conjugated system, so that the thermal stability of the material is improved, and the film-forming property of the organic photoelectric material in the processing process is further improved; the cross conjugated structure in the molecule and the electron-withdrawing group in the substituent group act together to ensure that the molecule has stronger reduction potential, thereby assisting the hole transport layer to carry out high-efficiency hole injection. The organic photoelectric material provided by the invention is used as a guest material of a hole injection layer of an OLED device, can effectively increase charge injection, reduce the driving voltage of the OLED device, and improve the service life and the overall efficiency of the device.)

1. An organic photoelectric material, wherein the organic photoelectric material has a structure represented by formula I:

wherein R is₁-R₉Each independently selected from hydrogen, halogen, cyano, nitro, sulfonic acidOne of carboxyl, carbonyl, aldehyde, acyl, tertiary amine cation, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, alkynyl or isocyano, and R₁-R₉Not hydrogen at the same time.

2. The organic photoelectric material according to claim 1, wherein the halogen is F, Cl, Br, or I;

preferably, the substituted or unsubstituted alkyl is a substituted or unsubstituted C1-C10 linear or branched alkyl;

preferably, the substituted or unsubstituted cycloalkyl is substituted or unsubstituted C3 to C30 cycloalkyl;

preferably, the substituted or unsubstituted aryl group is a substituted or unsubstituted C6-C30 aryl group;

preferably, the substituted or unsubstituted heteroaryl is substituted or unsubstituted C3-C30 heteroaryl;

preferably, the substituent in the substituted alkyl, substituted aryl, substituted heteroaryl, substituted cycloalkyl and substituted alkenyl is F, Cl, Br, I, cyano, trifluoromethyl, sulfonic group, nitro, carboxyl, carbonyl, aldehyde group, tertiary amine cation, alkoxy or aryloxy;

preferably, said R is₁-R₉Each independently selected from one of fluoro-substituted phenyl, trifluoromethyl-substituted phenyl, chloro-substituted phenyl, cyano-substituted phenyl, cyclohexyl, fluoro-substituted cyclohexyl, trifluoromethyl-substituted cyclohexyl, cyano-substituted cyclohexyl, trifluoromethyl, trichloromethyl, methyl, ethyl, fluoro-substituted ethyl, chloro-substituted ethyl, cyano-substituted ethyl, butyl, fluoro-substituted butyl, cyano-substituted butyl, pentyl, fluoro-substituted pentyl, cyano-substituted pentyl, dicyano-substituted vinyl, cyano-substituted alkoxy, cyano-substituted aryloxy, fluoro-substituted alkoxy, or fluoro-substituted aryloxy;

preferably, said R is₁-R₉In at least containsThere is one of F, Cl, Br, I, cyano, fluoro-substituted phenyl, trifluoromethyl-substituted phenyl, chloro-substituted phenyl, cyano-substituted phenyl, fluoro-substituted cyclohexyl, trifluoromethyl-substituted cyclohexyl, cyano-substituted cyclohexyl, trifluoromethyl, trichloromethyl, fluoro-substituted ethyl, chloro-substituted ethyl, cyano-substituted ethyl, fluoro-substituted butyl, cyano-substituted butyl, fluoro-substituted pentyl, cyano-substituted butyl, dicyano-substituted vinyl, cyano-substituted alkoxy, cyano-substituted aryloxy, fluoro-substituted alkoxy, fluoro-substituted aryloxy, sulfonic acid, nitro, carboxyl, carbonyl, aldehyde or tertiary amine cation.

3. The organic photoelectric material according to claim 1 or 2, wherein the organic photoelectric material is any one of or a combination of at least two of the following compounds 1 to 11:

4. a method for preparing the organic photoelectric material according to any one of claims 1 to 3, wherein the method comprises: the compound shown in the formula II reacts under the combined action of an organic lithium reagent and a catalyst to generate the organic photoelectric material shown in the formula I, wherein the reaction formula is as follows:

wherein R is₁-R₉Each independently selected from hydrogen, halogen, cyano, nitro, sulfonic acid, carboxyl, carbonyl, aldehyde, acyl, tertiary amine cation, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstitutedAnd R is one of a cycloalkyl, substituted or unsubstituted alkenyl, alkynyl or isocyano group₁-R₉Not hydrogen at the same time.

5. The preparation method according to claim 4, wherein the molar ratio of the compound represented by the formula II to the organic lithium reagent is 1 (2-2.5), preferably 1: 2.2;

preferably, the organolithium reagent is tert-butyllithium;

preferably, the catalyst comprises a metal chloride and a peroxide;

preferably, the metal halide is ferric chloride;

preferably, the peroxide is di-tert-butyl peroxide;

preferably, the molar ratio of the peroxide to the compound shown in the formula II is (0.8-1.3): 1, and more preferably 1: 1;

preferably, the molar amount of the metal halide is 2 to 8%, more preferably 5%, of the molar amount of the compound represented by formula II.

6. The preparation method according to claim 4 or 5, characterized in that it comprises in particular the steps of:

(1) mixing the compound shown in the formula II with an organic solvent, cooling, and then adding an organic lithium reagent into the mixture for reaction to obtain a reaction intermediate;

(2) mixing the reaction intermediate obtained in the step (1) with a metal halide solution, then adding peroxide for reaction, and adding a quenching agent to terminate the reaction when the reaction end point is reached, so as to obtain the organic photoelectric material shown in the formula I;

preferably, the cooling temperature in the step (1) is below-60 ℃, and further preferably between-75 ℃ and-80 ℃;

preferably, the organic solvent in step (1) is selected from any one or a combination of at least two of n-heptane, n-pentane, diethyl ether or tetrahydrofuran, and is further preferably a mixed solvent of n-heptane and diethyl ether;

preferably, the volume ratio of the n-heptane to the diethyl ether is (0.5-3) to 1, and further preferably 1.5: 1;

preferably, the organolithium reagent of step (1) is added dropwise;

preferably, the temperature of the reaction in the step (1) is below-70 ℃, and further preferably between-75 ℃ and-80 ℃;

preferably, the reaction time in the step (1) is 5-40 min;

preferably, the metal halide solution in step (2) is a tetrahydrofuran solution of metal halide;

preferably, the temperature of the reaction of step (2) is room temperature;

preferably, the reaction time in the step (2) is 15-60 min, and more preferably 30 min;

preferably, the quenching agent of step (2) is methanol;

preferably, the reactions of step (1) and step (2) are carried out under stirring;

preferably, the reactions of step (1) and step (2) are both carried out in the presence of a protective gas, preferably nitrogen.

7. A hole injection layer for an OLED device, wherein the hole injection layer comprises a host material and a guest material, and the guest material is the organic photoelectric material according to any one of claims 1 to 3.

8. The hole injection layer for an OLED device according to claim 7, wherein the host material is an arylamine compound;

preferably, the molar ratio of the host material to the guest material in the hole injection layer is (25-38): 1, and more preferably 33.3: 1;

preferably, the thickness of the hole injection layer is 30 to 70nm, and more preferably 50 nm.

9. An OLED device comprising at least an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode, wherein the hole injection layer is the hole injection layer for the OLED device of claim 7 or 8.

10. An electronic device, characterized in that it comprises an OLED device as claimed in claim 9.

Technical Field

The invention belongs to the technical field of organic electroluminescence, and particularly relates to an organic photoelectric material, and a preparation method and application thereof.

Background

With the development of organic electronics, organic electroluminescent devices (OLEDs) are rapidly becoming research hotspots for people, and have great potential to replace mainstream liquid crystal displays, becoming a star technology in the display field. The increasing demand in the display field also drives the rapid development of OLED device structures and organic photoelectric materials, which are embodied as compounds and materials with new structures, functional groups and substituents, and simultaneously, the OLED device structures are continuously optimized and gradually developed from the initial sandwich structure into complex structures composed of multiple functional layers.

In the design of OLED devices, energy level matching is of great importance, and in the case of classical organic electroluminescent devices, the stacked structure thereof comprises: a cathode, an electron transport layer, a light emitting layer, a hole transport layer, and an anode; indium Tin Oxide (ITO) is generally used as an anode, but the work function of the ITO is high, and the energy level difference between the ITO and most hole transport materials reaches about 0.4 eV. Therefore, if a hole injection layer is added between the anode and the hole transport layer, on one hand, the injection of charges can be increased, and on the other hand, the overall efficiency and the service life of the device can be improved.

CN104183738A discloses an organic electroluminescent device and a method for manufacturing the same, the device includes an anode, a hole injection layer, a first hole transport layer, a first luminescent layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second luminescent layer, a second electron transport layer, an electron injection layer and a cathode, which are stacked in sequence, the charge generation layer includes an n-type layer, an intermediate layer and a p-type layer, wherein the n-type layer is an electron transport material, the intermediate layer is a metal doped with a phthalocyanine compound, the p-type layer is a lanthanide oxide doped with a hole injection material, the lanthanide oxide is at least one selected from praseodymium dioxide, praseodymium trioxide, ytterbium trioxide and samarium oxide, and the hole injection material is a triphenylamine compound; the energy level of a p-type layer in the organic electroluminescent device is matched with the HOMO energy level of a hole transport layer, so that a hole injection barrier can be reduced, the hole injection capability is improved, the transport of current carriers is facilitated, and the luminous efficiency is improved.

CN101295770A discloses a hole injection material of an organic electroluminescent device, a preparation method, an application thereof and the organic electroluminescent device, wherein the hole injection material is a mixture of graphite and aromatic tertiary amine according to the weight ratio of (0.01-5): 100, the aromatic tertiary amine has a symmetrical structure and poor moldability, and the introduction of the graphite enables the amorphous stability of a hole injection layer to be better, the film forming performance to be better, the device to be more stable, the service life to be prolonged, and the hole injection efficiency to be improved.

CN104638152A discloses an organic electroluminescent device, a method for manufacturing the same, and a display device, wherein the organic electroluminescent device includes a hole injection layer, the hole injection layer is composed of a hole injection material layer and a radical luminescent material layer, and the hole injection material layer and the radical luminescent material layer are alternately stacked and distributed; wherein the radical-emitting material is a compound havingA compound of structure, the hole injection material being HATCN; due to the deep energy level characteristic and strong electron absorption capacity of the HATCN, a single electron on the free radical luminescent material is transited to the LUMO of the HATCN, so that charge transfer occurs at the interface of the free radical luminescent material layer and the hole injection material layer, electron pair energy does not need to be overcome, hole injection and potential barrier are effectively reduced, hole injection efficiency is improved, and the performance of the organic electroluminescent device is further improved.

However, in the prior art, the main material of the hole injection material is mostly an aromatic amine compound, and the most of the doping materials of the doped hole injection layer are lewis acid type metal complexes, allyl, halogens and quinone compounds, wherein the allyl compound has more steps and higher cost in the synthesis, and the metal complexes and halogens may have the problem of poor stability in the processing process.

Therefore, the development of an organic photoelectric material which has high hole injection efficiency, good stability and easy preparation is the research focus in the field.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide an organic photoelectric material, a preparation method and an application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides an organic photoelectric material, which has a structure shown in formula I:

wherein R is₁-R₉Each independently selected from one of hydrogen, halogen, cyano, nitro, sulfonic acid, carboxyl, carbonyl, aldehyde, acyl, tertiary amine cation, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, alkynyl or isocyano, and R₁-R₉Not hydrogen at the same time.

The organic photoelectric material provided by the invention contains a skeleton structure for replacing butadiene, wherein two double bonds form a conjugated system, so that the internal energy of the whole molecule is reduced, the thermal stability is improved, and the film-forming property of the organic photoelectric material in the processing process is further improved; in addition, the molecular structure of the organic photoelectric material at least comprises an electron-withdrawing group, and the cross conjugated structure in the molecule and the electron-withdrawing group in the substituent group have the combined action, so that the molecule has stronger reduction potential, and the hole transport layer is assisted to carry out high-efficiency hole injection.

When the organic photoelectric material provided by the invention is doped into a host material of a hole injection layer as a guest material, the HOMO energy level of the host material is close to the LUMO energy level of the guest material, and the energy level difference between the HOMO energy level and the LUMO energy level of the guest material can reach less than or equal to 0.30eV, so that electrons of the HOMO energy level can be favorably transferred to the LUMO energy level of the guest material, a free hole is formed, and the conductivity of an OLED device is improved; meanwhile, the organic photoelectric material provided by the invention can be used as an object material, and an interface energy band can be bent, so that holes can be injected in a tunneling mode, and the hole injection efficiency is improved. Therefore, the organic photoelectric material provided by the invention is used as a guest material of a hole injection layer of an OLED device, can effectively increase charge injection, reduce the driving voltage of the OLED device, and improve the service life and the overall efficiency of the device.

Preferably, the halogen is F, Cl, Br or I;

preferably, the substituted or unsubstituted alkyl group is a substituted or unsubstituted C1-C10 linear or branched alkyl group, such as a substituted or unsubstituted C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10 linear alkyl group, a substituted or unsubstituted C3, C4, C5, C6, C7, C8, C9 or C10 branched alkyl group; the C1-C10 linear or branched alkyl group illustratively includes, but is not limited to, any of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, tert-butyl, isopropyl, 3-methylhexyl, 3-ethylhexyl, 3-methylheptyl, or 2-methylbutyl.

Preferably, the substituted or unsubstituted cycloalkyl group is a substituted or unsubstituted C3 to C30 cycloalkyl group, such as a substituted or unsubstituted C3, C4, C5, C6, C7, C8, C9, C10, C11, C13, C15, C18, C20, C23, C25, C26, C28 or C29 cycloalkyl group.

Preferably, the substituted or unsubstituted aryl group is a substituted or unsubstituted C6 to C30 aryl group, such as a substituted or unsubstituted C6, C7, C8, C9, C10, C13, C15, C17, C20, C23, C25, C28, C29 or C30 aryl group; the C6 to C30 aryl group illustratively includes, but is not limited to, any one of phenyl, biphenyl, naphthyl, anthryl or pyrenyl.

Preferably, the substituted or unsubstituted heteroaryl group is a substituted or unsubstituted C3 to C30 heteroaryl group, such as a substituted or unsubstituted C3, C4, C5, C6, C7, C8, C9, C10, C11, C13, C15, C17, C20, C23, C25, C27, C29 or C30, and the heteroatom in the heteroaryl group is N, O, S, P, etc.; the C3-C30 heteroaryl group illustratively includes, but is not limited to, any one of pyridyl, pyrrolyl, thiazolyl, carbazolyl, indolyl, quinolinyl, furanyl, piperidinyl, thienyl, imidazolyl, or pyrazinyl.

Preferably, the substituent in the substituted alkyl, substituted aryl, substituted heteroaryl, substituted cycloalkyl, substituted alkenyl is F, Cl, Br, I, cyano, trifluoromethyl, sulfonic acid, nitro, carboxyl, carbonyl, aldehyde, tertiary amine cation, alkoxy or aryloxy.

Preferably, said R is₁-R₉Each independently selected from one of fluoro-substituted phenyl, trifluoromethyl-substituted phenyl, chloro-substituted phenyl, cyano-substituted phenyl, cyclohexyl, fluoro-substituted cyclohexyl, trifluoromethyl-substituted cyclohexyl, cyano-substituted cyclohexyl, trifluoromethyl, trichloromethyl, methyl, ethyl, fluoro-substituted ethyl, chloro-substituted ethyl, cyano-substituted ethyl, butyl, fluoro-substituted butyl, cyano-substituted butyl, pentyl, fluoro-substituted pentyl, cyano-substituted pentyl, dicyano-substituted vinyl, cyano-substituted alkoxy, cyano-substituted aryloxy, fluoro-substituted alkoxy, or fluoro-substituted aryloxy.

Preferably, said R is₁-R₉Wherein the group contains at least one of F, Cl, Br, I, cyano, fluorine-substituted phenyl, trifluoromethyl-substituted phenyl, chlorine-substituted phenyl, cyano-substituted phenyl, fluorine-substituted cyclohexyl, trifluoromethyl-substituted cyclohexyl, cyano-substituted cyclohexyl, trifluoromethyl, trichloromethyl, fluorine-substituted ethyl, chlorine-substituted ethyl, cyano-substituted ethyl, fluorine-substituted butyl, cyano-substituted butyl, fluorine-substituted pentyl, cyano-substituted butyl, dicyano-substituted vinyl, cyano-substituted alkoxy, cyano-substituted aryloxy, fluorine-substituted alkoxy, fluorine-substituted aryloxy, sulfonic acid group, nitro group, carboxyl group, carbonyl group, aldehyde group or tertiary amine cation.

Preferably, the organic photoelectric material is any one or a combination of at least two of the following compounds 1-11:

in another aspect, the present invention provides a method for preparing an organic photoelectric material, the method comprising: the compound shown in the formula II reacts under the combined action of an organic lithium reagent and a catalyst to generate the organic photoelectric material shown in the formula I, wherein the reaction formula is as follows:

wherein R is₁-R₉Each independently selected from one of hydrogen, halogen, cyano, nitro, sulfonic acid, carboxyl, carbonyl, aldehyde, acyl, tertiary amine cation, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, alkynyl or isocyano, and R₁-R₉Not hydrogen at the same time.

Preferably, the molar ratio of the compound represented by the formula II to the organic lithium reagent is 1 (2-2.5), such as 1:1.2.05, 1:2.15, 1:2.2, 1:2.25, 1:2.3, 1:2.35, 1:2.4, 1:2.45 or 1:2.5, and more preferably 1: 2.2;

preferably, the organolithium reagent is tert-butyllithium;

preferably, the catalyst comprises a metal chloride and a peroxide;

preferably, the metal halide is ferric chloride;

preferably, the peroxide is di-tert-butyl peroxide;

preferably, the molar ratio of the peroxide to the compound of formula II is (0.8-1.3): 1, such as 0.85:1, 0.9:1, 0.95:1, 1:1, 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1 or 1.3:1, more preferably 1: 1;

preferably, the molar amount of the metal halide is 2 to 8% of the molar amount of the compound represented by formula II, for example, 2.1%, 2.3%, 2.5%, 2.7%, 3%, 3.3%, 3.5%, 3.7%, 4%, 4.5%, 5%, 5.3%, 5.5%, 5.7%, 6%, 6.5%, 7%, 7.5% or 8%, and more preferably 5%.

Preferably, the preparation method specifically comprises the following steps:

(1) mixing the compound shown in the formula II with an organic solvent, cooling, and then adding an organic lithium reagent into the mixture for reaction to obtain a reaction intermediate;

(2) mixing the reaction intermediate obtained in the step (1) with a metal halide solution, then adding peroxide for reaction, and adding a quenching agent to terminate the reaction when the reaction end point is reached, so as to obtain the organic photoelectric material shown in the formula I;

preferably, the temperature of the cooling in step (1) is below-60 ℃, such as-65 ℃, -68 ℃, -70 ℃, -73 ℃, -75 ℃, -80 ℃, -83 ℃, -85 ℃, -90 ℃ or-100 ℃, and the specific values therebetween are limited to the space and the simplicity, and the invention is not exhaustive list of the specific values included in the range, and more preferably-75 ℃ to-80 ℃.

Preferably, the organic solvent in step (1) is selected from any one or a combination of at least two of n-heptane, n-pentane, diethyl ether or tetrahydrofuran, and is further preferably a mixed solvent of n-heptane and diethyl ether;

preferably, the volume ratio of the n-heptane to the diethyl ether is (0.5-3): 1, such as 0.7:1, 0.9:1, 1:1, 1.3:1, 1.5:1, 1.7:1, 2:1, 2.5:1 or 2.8:1, and more preferably 1.5: 1.

Preferably, the organolithium reagent of step (1) is added dropwise;

preferably, the temperature of the reaction in step (1) is below-70 ℃, such as-71 ℃, -73 ℃, -75 ℃, -77 ℃, -78 ℃, -80 ℃, -83 ℃, -85 ℃, -90 ℃ or-100 ℃, and the specific values between the above values are limited to the space and the conciseness, and the invention does not exhaustive list the specific values included in the range, and further preferably-75 ℃ to-80 ℃.

Preferably, the reaction time in step (1) is 5-40 min, such as 6min, 8min, 10min, 13min, 15min, 18min, 20min, 23min, 25min, 28min, 30min, 33min, 35min or 39min, and the specific points between the above values are limited by space and for simplicity, and the invention is not exhaustive.

Preferably, the metal halide solution in step (2) is a tetrahydrofuran solution of metal halide;

preferably, the temperature of the reaction of step (2) is room temperature;

preferably, the reaction time in step (2) is 15-60 min, such as 17min, 20min, 23min, 25min, 28min, 30min, 33min, 35min, 38min, 40min, 45min, 50min, 55min or 59min, and the specific points between the above values are limited by space and simplicity, and the invention does not exhaust the specific points included in the range, and more preferably 30 min.

Preferably, the quenching agent of step (2) is methanol;

preferably, the reactions of step (1) and step (2) are carried out under stirring;

preferably, the reactions of step (1) and step (2) are both carried out in the presence of a protective gas, preferably nitrogen.

In another aspect, the present invention provides a hole injection layer for an OLED device, the hole injection layer including a host material and a guest material, the guest material being an organic photoelectric material as described above.

Preferably, the main body material is an arylamine compound;

preferably, the molar ratio of the host material to the guest material in the hole injection layer is (25-38: 1), for example, 25.5:1, 26:1, 26.5:1, 27:1, 28:1, 29:1, 30:1, 31:1, 32:1, 32.5:1, 33:1, 33.5:1, 34:1, 35:1, 36:1, 37:1, or 37.5:1, and more preferably 33.3: 1.

Preferably, the thickness of the hole injection layer is 30-70 nm, such as 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm or 68nm, and the specific values therebetween are limited by space and for brevity, the invention is not exhaustive of the specific values included in the range, and more preferably 50 nm.

In another aspect, the present invention provides an OLED device comprising at least an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode, the hole injection layer being the hole injection layer for OLED devices as described above.

In another aspect, the present invention provides an electronic device comprising an OLED device as described above.

Compared with the prior art, the invention has the following beneficial effects:

the organic photoelectric material provided by the invention contains a skeleton structure for replacing butadiene, wherein two double bonds form a conjugated system, so that the internal energy of the whole molecule is reduced, the thermal stability is improved, and the film-forming property of the organic photoelectric material in the processing process is further improved; the cross conjugated structure in the molecule and the electron-withdrawing group in the substituent group act together to ensure that the molecule has stronger reduction potential, thereby assisting the hole transport layer to carry out high-efficiency hole injection. The organic photoelectric material provided by the invention is used as a guest material of a hole injection layer of an OLED device, can effectively increase charge injection, reduce the driving voltage of the OLED device, and improve the service life and the overall efficiency of the device.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The raw materials of tert-butyl lithium (t-BuLi), di-tert-butyl peroxide (DTBP), n-heptane, diethyl ether, tetrahydrofuran, methanol, ferric chloride and reagents used for separation and purification in examples 1 to 8 of the present invention were all purchased from Profenox reagent company, and the compound 1a, the compound 2a, the compound 3a, the compound 4a, the compound 5a, the compound 6a, the compound 7a and the compound 8a were all commercially available chemical products.