Crosslinkable hole transport polymer and application thereof

Abstract

The invention belongs to the field of photoelectricity, and discloses a crosslinkable hole transport polymer and application thereof. The cross-linkable hole transport polymer has a structural formula as shown in the specification. The cross-linkable hole transport polymer contains a carbazole unit, has relatively strong hole transport performance, can make up the problem of relatively low hole mobility of a traditional hole transport polymer, and obtains relatively high hole transport performance. The cross-linkable hole transport polymer has good solubility, can be used for preparing a large-area film through solution processing methods such as spin coating, ink-jet printing and printing, can realize cross-linking curing under mild conditions such as heat, light and an initiator, has good solvent resistance, can be used for preparing another layer of film through solution processing, and can be applied to the field of hole transport. And a multi-layer solution processing device is realized. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of optoelectronics, and particularly relates to a class of cross-linkable hole transport polymers and applications thereof. Background Art

[0002] In order to develop new information display technology to replace liquid crystal display (LCD), organic light emitting diode (OLED) appeared in people's field of vision. Organic light emitting diode has the characteristics of self-luminescence, low cost, wide viewing angle, low energy consumption, high efficiency, full-color display and flexible display, so it is considered to be a new generation of display technology that can replace liquid crystal display. In recent years, quantum dots have set off a wave of enthusiasm in academia and industry due to their unique properties, which is a major advancement for information technology. Quantum dot diode (QLED) is now considered to be the most promising display technology for the next generation due to its advantages such as good stability, adjustable emission color and high purity. Therefore, research and development of more complete organic light emitting diode and quantum dot light emitting diode technology is of great significance to the display and lighting fields.

[0003] Hole transport materials are important components of organic light-emitting diodes and quantum dot light-emitting diodes. High-performance hole transport materials need to meet the following conditions at the same time: (1) high optical transparency; (2) high carrier mobility; (3) appropriate energy level; and (4) good thermal stability and chemical stability.

[0004] There is a large hole injection barrier between the polymer hole transport material represented by poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-p-butylphenyl))] (TFB) and the light-emitting layer material, which limits the device performance of organic light-emitting diodes and quantum dot light-emitting diodes. In addition, the ink solvents of light-emitting materials and quantum dot materials usually contain high-boiling point ester solvents. TFB has a certain solubility in such ester solvents, and it is impossible to achieve solvent resistance and prepare printed light-emitting devices. Therefore, the development of cross-linkable hole transport polymers with strong hole transport properties is the key to promoting the development of printed organic light-emitting diodes and quantum dot light-emitting diodes. Summary of the invention

[0005] To overcome the disadvantages and deficiencies of the above-mentioned prior art, the primary object of the present invention is to provide a class of crosslinkable hole-transporting polymers. This class of polymers contains carbazole units connected at the 3,6-positions. The carbazole units have a large conjugated plane and strong electron-donating ability, enabling a relatively high hole mobility. In addition, the carbazole units have high rigidity, and the polymers constructed based on these units have a low energy disorder, with a reduction in the energy level tail states, which is beneficial for reducing leakage current as a hole-transporting material. Such polymers contain chemically reactive groups such as styrene and benzocyclobutene on the side chains, and can be crosslinked and cured under conditions such as heat, light, and initiators, and are used for the preparation of multi-layer solution-processed devices. Such crosslinkable hole-transporting polymers also have high optical transparency, have great potential as hole-transporting polymers, and can also achieve different energy levels and carrier mobilities by adjusting the content of the polymerization units.

[0006] Another object of the present invention is to provide a crosslinkable hole-transporting polymer prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above crosslinkable hole-transporting polymer in the field of organic optoelectronics. Such polymers have good solubility and can be used to prepare large-area thin films by solution processing methods such as spin coating, inkjet printing, and printing.

[0008] The object of the present invention is achieved by the following solutions:

[0009] A class of crosslinkable hole-transporting polymers, the chemical structural formula of which satisfies the following general formula:

[0010]

[0011] In the formula: x, y, and z are the molar fractions of each unit component, satisfying: 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1; n is the number of repeating units, and n = 10 to 1000;

[0012] R is H, an alkyl group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 20 carbon atoms, or an aromatic heterocyclic group with 3 to 20 carbon atoms.

[0013] Ar1 is an aromatic hydrocarbon group with 6 to 60 carbon atoms or an aromatic heterocyclic group with 3 to 60 carbon atoms.

[0014] Furthermore, the above-mentioned Ar1 is preferably one or more of the following chemical structures or derivatives of the following structures:

[0015]

[0016] Here, R1 is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 60 carbon atoms, or an aromatic heterocyclic group having 3 to 60 carbon atoms.

[0017] Ar2 is a cross-linkable group, preferably one or more of the following chemical structures or derivatives of the following structures:

[0018]

[0019] Here, m is a natural number from 0 to 20, including 0.

[0020] Preferably, the chemical structure of the cross-linkable hole transport polymer is one of the following structures:

[0021]

[0022]

[0023] The cross-linkable hole transport polymer has good solubility and can be dissolved in (such as tetrahydrofuran, toluene, xylene, chlorobenzene, chloroform, etc.).

[0024] The cross-linkable hole transport polymer can be cross-linked and cured under conditions of heat, light, initiator, etc., and has good solvent resistance.

[0025] The above-mentioned polymer containing bicarbazole units is used in preparing the hole transport layer of organic light emitting diodes and quantum dot light emitting diodes.

[0026] Furthermore, the use of the above-mentioned type of cross-linkable hole transport polymer to prepare the hole transport layer of the organic light-emitting diode and the quantum dot light-emitting diode includes the following steps: dissolving the cross-linkable hole transport polymer in an organic solvent, then forming a film by spin coating, inkjet printing or printing, and treating it under conditions of heat, light, initiator, etc. to obtain the hole transport layer of the organic light-emitting diode and the quantum dot light-emitting diode.

[0027] The organic solvent is at least one of tetrahydrofuran, toluene, xylene, chlorobenzene or chloroform.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] (1) The cross-linkable hole transport polymer of the present invention contains carbazole units and has strong hole transport performance, which can make up for the problem of low hole mobility of traditional hole transport polymers and obtain higher hole transport performance.

[0030] (2) The cross-linkable hole transport polymer of the present invention can be cross-linked and cured under mild conditions such as heat, light, and initiators, and then has good solvent resistance. Another thin film layer can be prepared thereon by solution processing to realize a multi-layer solution-processed device.

[0031] (3) The cross-linkable hole transport polymer of the present invention has high optical transparency and carrier mobility, has great potential as a hole transport polymer, and can also achieve different energy levels by adjusting the content of the polymerized unit. This type of polymer has good solubility and can be used to prepare large-area thin films by solution processing methods such as spin coating, inkjet printing, and printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The cyclic voltammetry curve of polymer P1.

[0033] Figure 2 This is the thermogravimetric curve of polymer P2.

[0034] Figure 3 is the differential scanning calorimetry curve of polymer P2.

[0035] Figure 4 This is the absorption spectrum of polymer P1 in thin film state.

[0036] Figure 5 This is the photoemission spectrum of polymer P1 in thin film state.

[0037] Figure 6 This is the UV-visible absorption spectrum of the polymer P1 film after thermal annealing at 220°C for 30 minutes and before and after rinsing with tetrahydrofuran solvent. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the examples and drawings, but the embodiments of the present invention are not limited thereto. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0039] Unless otherwise specified, the reagents used in the examples can be purchased from the market.

[0040] Example 1: Preparation of Compound P1

[0041] (1) Preparation of Compound 1

[0042] Under nitrogen protection, 3,6-dibromocarbazole (3.25 g, 10 mmol), 1,4-dibromobutane (4.32 g, 20 mmol), potassium carbonate (4.14 g, 30 mmol) and 120 mL N,N-dimethylformamide were added to a 300 mL two-necked bottle and heated to 90 ° C for 12 hours. After the reaction was completed, the product was extracted with dichloromethane and washed five times with a saturated sodium chloride aqueous solution. After removing the organic phase solvent, the crude product was purified by column chromatography using petroleum ether as an eluent to obtain 4.14 g of a white solid with a yield of 91%. 1 H NMR, 13 CNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0043] (2) Preparation of Compound 2

[0044] Under nitrogen protection, compound 1 (2.30 g, 5 mmol), 4-vinylphenol (0.72 g, 6 mmol), potassium hydroxide (0.84 g, 15 mmol) and 30 mL of 1,4-dioxane were added to a two-necked bottle, and the mixture was stirred and heated to 80°C for 5 hours. After the reaction was completed, the product was extracted with dichloromethane and washed five times with a saturated sodium chloride aqueous solution. After removing the organic phase solvent, the crude product was purified by column chromatography using petroleum ether: dichloromethane (2:1, v:v) as an eluent to obtain 1.05 g of a pale white solid with a yield of 42%. 1 HNMR, 13 CNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0045] (3) Preparation of Compound P1

[0046] Under nitrogen protection, 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (32.1 mg, 0.5 mmol), 3,6-dibromo-9-(2-ethylhexyl)carbazole (17.5 mg, 0.4 mmol) and compound 2 (5.0 mg, 0.1 mmol), palladium acetate (6 mg) and tricyclohexylphosphoric acid (6 mg) were dissolved in 15 mL toluene and 2 mL tetraethylammonium hydroxide aqueous solution (20 wt / v%), stirred and heated to 85°C and reacted for 24 hours. Phenylboric acid (100 mg) and bromobenzene (0.2 mL) were added to terminate the reaction and then cooled to room temperature. The reaction solution was dropped into 200 mL methanol to precipitate the precipitate and filtered. The precipitate was extracted with methanol, acetone and n-hexane in turn. Finally, it was dissolved in 20 mL of chloroform and then dropped into 200 mL of methanol for precipitation. After filtration and drying, 298 mg of white solid was obtained with a yield of 88%. 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 98 KDa, PDI = 1.98.

[0047] The chemical reaction equations for synthesizing compounds 1 to 2 are shown below:

[0048]

[0049] The chemical reaction equation for synthesizing compound P1 is shown below:

[0050]

[0051] Figure 1 The cyclic voltammetry curve of polymer P1 shows that the oxidation potential of polymer P1 is 1.02 V, the calibrated ferrocene oxidation potential is 0.42 V, and the HOMO energy level of polymer P1 is calculated to be -5.42 eV, which is between the commonly used hole injection layer and the light-emitting layer, and is suitable as a hole transport layer material.

[0052] Figure 4 This is the absorption spectrum of polymer P1 in thin film state. The absorption distribution of the material is in the ultraviolet and near-ultraviolet region. According to the thin film absorption spectrum, the absorption edge is 401nm, and the calculated optical band gap is 3.09eV. It can be used as a hole transport material for red, green and blue primary color devices.

[0053] Figure 5 This is the photoemission spectrum of polymer P1 in the thin film state. The material has a higher singlet energy level, which is beneficial to confine the exciton energy in the light-emitting layer.

[0054] Figure 6 This is the UV-visible absorption spectrum of the polymer P1 film before and after rinsing with tetrahydrofuran solvent after thermal annealing at 220°C for 30 minutes. It can be seen from the figure that the absorption intensity of the film does not change basically before and after rinsing, indicating that the P1 film has achieved sufficient cross-linking after thermal annealing at 220°C for 30 minutes and has good solvent resistance.

[0055] Example 2: Preparation of Compound P2

[0056] The synthesis method of polymer P2 is similar to that of P1, with the only difference being step (3). According to the synthesis method of P1 in step (3) of Example 1, the reaction monomers were replaced with 2,2'-[6,6,12,12-tetra-n-octyl-6,12-dihydroindeno[1,2-B]fluorene-2,8-bis(boronic acid)pinacol ester (47.8 mg, 0.5 mmol), 3,6-dibromo-9-(2-ethylhexyl)carbazole (17.5 mg, 0.4 mmol) and compound 2 (5.0 mg, 0.1 mmol). 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 105 KDa, PDI = 2.16.

[0057] The synthetic chemical reaction equation of polymer P2 is as follows:

[0058]

[0059] Figure 2 The thermogravimetric curve of polymer P2 shows that the thermal decomposition temperature of polymer P2 is 410°C, which indicates that the polymer has high thermal stability.

[0060] Figure 3 The differential scanning calorimetry curve of polymer P2 shows that the glass transition temperature of the polymer is 138°C, indicating that the material has good morphological stability.

[0061] Example 3: Synthesis of polymer P3

[0062] The synthesis method of polymer P3 is similar to that of P1, with the only difference being step (3). According to the synthesis method of P1 in step (3) of Example 1, the reaction monomers were replaced with 2,7-di(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecanylcarbazole (32.9 mg, 0.5 mmol), 3,6-dibromo-9-(2-ethylhexyl)carbazole (8.7 mg, 0.2 mmol) and compound 2 (15.0 mg, 0.3 mmol). 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 95 KDa, PDI = 1.88.

[0063] The synthetic chemical reaction equation of polymer P3 is as follows:

[0064]

[0065] Example 4: Synthesis of polymer P4

[0066] (1) Preparation of Compound 3

[0067] Under nitrogen protection, 3,6-dibromocarbazole (3.25 g, 10 mmol), 4-bromobenzocyclobutene (3.66 g, 20 mmol), potassium carbonate (4.14 g, 30 mmol) and 120 mL N,N-dimethylformamide were added to a 300 mL two-necked bottle and heated to 90 ° C for 12 hours. After the reaction was completed, the product was extracted with dichloromethane and washed five times with a saturated sodium chloride aqueous solution. After removing the organic phase solvent, the crude product was purified by column chromatography using petroleum ether as an eluent to obtain 4.14 g of a white solid with a yield of 91%. 1 H NMR, 13 CNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0068] (2) Synthesis of polymer P4

[0069] The synthesis method of polymer P4 is similar to that of P1, with the only difference being step (3). According to the synthesis method of P1 in step (3) of Example 1, the reaction monomers were replaced with 2,7-di(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (32.1 mg, 0.5 mmol), 3,6-dibromo-9-(2-ethylhexyl)carbazole (13.1 mg, 0.3 mmol) and compound 3 (8.5 mg, 0.2 mmol). 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 92 KDa, PDI = 1.93.

[0070] The synthetic chemical reaction equation for compound 3 is shown below:

[0071]

[0072] The synthetic chemical reaction equation of polymer P4 is shown below:

[0073]

[0074] Example 5: Synthesis of polymer P5

[0075] (1) Preparation of Compound 4

[0076] Under nitrogen protection, compound 1 (2.30 g, 5 mmol), 4-hydroxybenzocyclobutene (0.72 g, 6 mmol), potassium hydroxide (0.84 g, 15 mmol) and 30 mL of 1,4-dioxane were added to a two-necked bottle, and the mixture was stirred and heated to 80 ° C for 5 hours. After the reaction was completed, the product was extracted with dichloromethane and washed five times with a saturated sodium chloride aqueous solution. After removing the organic phase solvent, the crude product was purified by column chromatography using petroleum ether: dichloromethane (3:1, v:v) as an eluent to obtain 1.32 g of a pale white solid with a yield of 53%. 1 H NMR, 13 CNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0077] (2) Synthesis of polymer P5

[0078] The synthesis method of polymer P5 is similar to that of P1, with the only difference being step (3). According to the synthesis method of P1 in step (3) of Example 1, the reaction monomers were replaced with 2,7-di(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (32.1 mg, 0.5 mmol), 3,6-dibromo-9-(2-ethylhexyl)carbazole (19.7 mg, 0.45 mmol) and compound 4 (2.5 mg, 0.05 mmol). 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 86 KDa, PDI = 1.90.

[0079] The synthetic chemical reaction equation for compound 4 is shown below:

[0080]

[0081] The synthetic chemical reaction equation of polymer P5 is shown below:

[0082]

[0083] Example 6: Synthesis of polymer P6

[0084] The synthesis method of polymer P6 is similar to that of P1, with the only difference being step (3). According to the synthesis method of P1 in step (3) of Example 1, the reaction monomers were replaced with 2,7-di(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (32.1 mg, 0.5 mmol), 3,6-dibromo-9-(4-tert-butylphenyl)carbazole (20.6 mg, 0.45 mmol) and compound 4 (2.5 mg, 0.05 mmol). 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 91 KDa, PDI = 2.06.

[0085] The synthetic chemical reaction equation of polymer P6 is as follows:

[0086]

[0087] Example 7: Synthesis of polymer P7

[0088] (1) Preparation of Compound 5-6

[0089] At room temperature, 4-bromostyrene (9.15 g, 50 mmol) was reacted with magnesium in anhydrous tetrahydrofuran to generate compound 5, and the organic phase was removed for later use. Under nitrogen protection, compound 5 (4.15 g, 40 mmol) and 1,6-dibromohexane (19.5 g, 80 mmol) were added to a two-necked bottle, and the mixture was reacted at room temperature for 2 hours. After the reaction was completed, the product was extracted with dichloromethane and washed five times with saturated sodium chloride aqueous solution. After removing the organic phase, the crude product was purified by column chromatography using petroleum ether: dichloromethane (5:1, v:v) as eluent to obtain 4.27 g of pale white solid with a yield of 80%. 1 H NMR, 13 CNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0090] (2) Preparation of Compound 7

[0091] Under nitrogen protection, 3,6-dibromocarbazole (3.25 g, 10 mmol), compound 6 (5.34 g, 20 mmol), potassium carbonate (4.14 g, 30 mmol) and 120 mL N,N-dimethylformamide were added to a 300 mL two-necked bottle and heated to 90 ° C for 12 hours. After the reaction was completed, the product was extracted with dichloromethane and washed five times with a saturated sodium chloride aqueous solution. After removing the organic phase solvent, the crude product was purified by column chromatography using petroleum ether as an eluent to obtain 4.32 g of a white solid with a yield of 87%. 1 H NMR, 13 CNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0092] The synthesis method of polymer P7 is similar to that of P1, with the only difference being step (3). According to the synthesis method of P1 in step (3) of Example 1, the reaction monomers were replaced with 2,7-di(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (3.21 g, 0.5 mmol), 3,6-dibromo-9-(2-ethylhexyl)carbazole (17.5 mg, 0.4 mmol) and compound 7 (5.1 mg, 0.1 mmol). 1 H NMR spectrum and elemental analysis confirmed that the target polymer was obtained. Gel permeation chromatography: Mn = 90 KDa, PDI = 1.99.

[0093] The chemical reaction equations for synthesizing compounds 5 to 7 are shown below:

[0094]

[0095] The chemical reaction equation of polymer P7 is shown below:

[0096]

[0097] Example 8: Preparation of quantum dot light emitting diodes

[0098] The ITO substrate was ultrasonically cleaned with tetrahydrofuran, deionized water, and isopropanol (10 minutes each) and dried. After plasma treatment, PEDOT:PSS was spin-coated on the ITO surface. The resulting PEDOT:PSS film (~40nm) was baked at 150°C for 10min. The PEDOT:PSS coated substrate was transferred in a glove box with oxygen and humidity <10ppm. Then, hole transport polymers (P1~P7) were spin-coated on the PEDOT:PSS layer. The resulting hole transport layer (~40nm) was annealed at 220°C for 30min. Then, a 15nm green light quantum dot layer (CdSe / CdZnSe / ZnS) and a 40nm Zn 0.85 Mg 0.15 O nanoparticle layer (ethanol solution) and baked at 90 °C for 10 min. Finally, the device was transferred to a vacuum chamber with a degree of <1×10 -4 Aluminum electrodes were deposited in a vacuum chamber of Pa and encapsulated using epoxy resin and cover glass. The QLED devices based on polymers P1 to P7 as hole transport layers are numbered D1 to D7. At the same time, a QLED device based on poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB, CAS: 220797-16-0) as a hole transport layer was also prepared as a control, numbered D0.

[0099] Table 1 Quantum dot light emitting device performance

[0100]

[0101]

[0102] As can be seen from Table 1, the devices based on P1 to P7 all exhibit lower turn-on voltage and higher external quantum efficiency, and the efficiency of the prepared QLED devices is higher than that of the control hole transport polymer TFB. This shows that these polymers can be used as hole transport materials to prepare high-efficiency quantum dot light-emitting diodes.

[0103] Example 9: Preparation of organic light emitting diodes

[0104] Take the pre-made indium tin oxide (ITO) glass with a square resistance of 15Ω, clean it with acetone, detergent, deionized water and isopropanol ultrasonically, and plasma treat it for 10 minutes. Spin-coat a polyethoxythiophene (PEDOT:PSS) film doped with polystyrene sulfonic acid on ITO with a thickness of 40nm. The PEDOT:PSS film is dried in a vacuum oven at 80℃ for 8 hours. Then, spin-coat the hole transport polymers P1~P3 on the PEDOT:PSS layer and anneal it at 220℃ for 30 minutes. Then, a xylene solution (1wt.%) of blue light emitting poly (9,9-dioctylfluorenyl-2,7-diyl) (PFO) is spin-coated on the surface of P1~P3 films with a thickness of 80nm as the light-emitting layer. Finally, a 1.5nm thick CsF layer and a 120nm thick metal Al layer were sequentially deposited on the light-emitting layer. The device structure was ITO / PEDOT:PSS / HTL / PFO / CsF / Al, and the devices were numbered D8 to D10. At the same time, OLED devices without a hole transport layer and with TFB as the transport layer were also prepared as controls. The device structure was ITO / PEDOT:PSS / PFO / CsF / Al, and they were numbered D11 and D12 respectively.

[0105] Table 2 Performance of polymer light emitting diode devices

[0106]

[0107] As can be seen from Table 2, the OLED device prepared using P1 to P3 as the hole transport layer reduces the device turn-on voltage and improves the device efficiency, indicating that the polymer can be used to prepare high-efficiency polymer light-emitting diodes.

[0108] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A class of cross-linkable hole transport polymers characterized by The chemical structural formula satisfies the following general formula: Wherein: x, y, and z are the mole fractions of each unit component, satisfying: 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1; n is the number of repeating units, n = 10 - 1000; R is H, an alkyl group with 1 - 10 carbon atoms, an aromatic hydrocarbon group with 6 - 20 carbon atoms, or an aromatic heterocyclic group with 3 - 20 carbon atoms; Ar1 is an aromatic hydrocarbon group with 6 - 60 carbon atoms or an aromatic heterocyclic group with 3 - 60 carbon atoms; Ar2 is a crosslinkable group.

2. The crosslinkable hole - transporting polymer according to claim 1, wherein: The Ar1 is one or more of the following chemical structures or derivatives of the following structures: Wherein, R1 is one of an alkyl group with 1 - 30 carbon atoms, a cycloalkyl group with 3 - 30 carbon atoms, an aromatic hydrocarbon group with 6 - 60 carbon atoms, or an aromatic heterocyclic group with 3 - 60 carbon atoms.

3. The crosslinkable hole - transporting polymer according to claim 1, wherein: Ar2 is one or more of the following chemical structures or derivatives of the following structures: Wherein, m is a natural number from 0 to 20, including 0.

4. The crosslinkable hole transport polymer according to claim 1, characterized in that Its chemical structural formula is one of the following structures: n＝10～1000。 5. Use of the crosslinkable hole - transporting polymer according to any one of claims 1 - 4 in preparing a hole - transporting layer of an organic light - emitting diode and a quantum - dot light - emitting diode.

6. Use of the crosslinkable hole transport polymer according to claim 5 in preparing a hole transport layer of an organic light emitting diode and a quantum dot light emitting diode, characterized in that Preparing the hole - transporting layer of the organic light - emitting diode and the quantum - dot light - emitting diode comprises the following steps: Dissolve the crosslinkable hole - transporting polymer in an organic solvent, and then form a film by spin - coating, ink - jet printing, or printing. After treatment under conditions of heat, light, or an initiator, the hole - transporting layer of the organic light - emitting diode and the quantum - dot light - emitting diode is obtained.

7. Use of the crosslinkable hole - transporting polymer according to claim 6 in preparing a hole - transporting layer of an organic light - emitting diode and a quantum - dot light - emitting diode, wherein: The organic solvent is at least one of tetrahydrofuran, toluene, xylene, chlorobenzene, or chloroform.

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