A photoresist having a carrier transport function and applications thereof

Abstract

The application discloses a photoresist with a function of promoting carrier transmission and application thereof, wherein the photoresist comprises dithiobis (benzene azide) and 1,3,5-tri-alkynyl benzene, and the molar ratio of the dithiobis (benzene azide) to the 1,3,5-tri-alkynyl benzene is (1:2)-(3:2). The azide group in the dithiobis (benzene azide) and the alkynyl group in the 1,3,5-tri-alkynyl benzene can be cross-linked under the driving of ultraviolet light, and by controlling the molar ratio and the exposure dose, a complete photoresist pattern can be obtained after development. The application further provides a composition for a hole transport layer, which comprises a hole transport material and the photoresist. The hole transport layer of a quantum dot light emitting diode prepared from the composition for the hole transport layer can not only effectively improve the solvent resistance of the hole transport layer, but also promote the hole transport, reduce the leakage current of the device, thereby greatly improving the performance of the QLED device.

Description

Technical Field

[0001] This invention relates to the fields of photoresist and light-emitting diode technology, specifically to a photoresist with the function of promoting carrier transport and its application in the preparation of hole transport layers for quantum dot light-emitting diodes. Background Technology

[0002] Quantum dot light-emitting diodes (QLEDs) are considered one of the core development directions of next-generation display technologies due to their outstanding advantages such as high color purity, wide color gamut, high brightness, and solution-based fabrication, showing enormous application potential in the display and lighting fields. However, in the actual operation of QLEDs, a mismatch between hole and electron injection and migration capabilities is a common problem. Specifically, the injection efficiency and mobility of holes are usually significantly lower than those of electrons, leading to an imbalance in charge distribution within the emissive layer, exacerbating non-radiative recombination processes, thereby reducing the device's luminous efficiency, increasing the turn-on voltage, and affecting its lifetime. Therefore, improving hole injection and transport capabilities to achieve charge balance is one of the key research directions for optimizing QLED performance.

[0003] Currently, the polymer material TFB (poly[(N,N'-(4-n-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine)-ALT-(9,9-di-n-octylfluorenyl-2,7-diyl)]) is widely used as the hole transport layer (HTL) in QLED devices due to its deep highest occupied molecular orbital (HOMO) energy level (approximately -5.3 eV), which matches well with the energy level of the commonly used hole injection material PEDOT:PSS, and its relatively high hole mobility. However, TFB faces severe challenges in the subsequent solution processing of the quantum dot light-emitting layer (EML). Typical quantum dot dispersion solvents, such as nonpolar organic solvents like toluene and chlorobenzene, have a strong dissolving effect on the TFB layer. When spin-coating the quantum dot layer using a solution method, the upper solvent severely corrodes the lower TFB film, leading to HTL destruction, interface deterioration, and even device short circuits, greatly limiting device performance and fabrication yield.

[0004] To address this issue, crosslinking HTL has become an effective strategy. By introducing a crosslinked structure, HTL can resist the erosion of non-polar solvents during subsequent processing, maintaining the integrity of the film. Currently, HTL crosslinking technology is mainly developing along two directions: thermal crosslinking and photocrosslinking. Thermal crosslinking methods typically require high processing temperatures (>180 °C), which is incompatible with temperature-sensitive flexible plastic substrates, and high temperatures may damage hole injection layers such as PEDOT:PSS. In contrast, photocrosslinking technology has the advantage of low-temperature or room-temperature processing, making it more suitable for the fabrication of flexible electronic devices. In 2017, Sun Baoquan et al. first reported the photocrosslinking of HTL by mixing TFB with a photosensitive bisbenzophenone derivative and irradiating it with ultraviolet light (Nanoscale Horiz., 2017, 2, 156). Subsequently, researchers, represented by Su Wenming's team, conducted systematic research on the photo-initiated CH insertion crosslinking mechanism. For example, they directly connected benzophenone crosslinking units to the side chains of TFB polymers (2020); synthesized a series of linear benzophenone crosslinking agents with different central alkyl chain lengths and optimized the crosslinking network density using a photothermal synergistic curing strategy (2022); and developed a novel tridentate diazo crosslinking agent, achieving simultaneous crosslinking and high-resolution non-destructive patterning of HTL and EML (2024).

[0005] While the aforementioned research has made progress in improving the solvent resistance and patterning capabilities of HTLs, current technology still faces a key bottleneck: widely used crosslinking agents (such as benzophenone, diazonium salts, and other derivatives) typically lack charge transport capabilities and are insulating materials. When these insulating crosslinking agents are incorporated into HTLs, they inevitably introduce charge transport barriers or traps, hindering hole migration. To minimize this negative impact, researchers have had to control the amount of crosslinking agent used to an extremely low level. However, excessively low crosslinking agent content may lead to insufficient crosslinking density, preventing the film from forming a uniform, dense, and completely solvent-resistant three-dimensional network structure. This can result in swelling or partial dissolution during subsequent processes, affecting interface quality. This contradiction between "reducing the amount of crosslinking agent to maintain charge transport performance" and "ensuring sufficient crosslinking agent to achieve complete crosslinking" severely restricts the reliable fabrication and commercialization of high-performance, high-resolution QLED devices. Therefore, there is an urgent need in the field for a method that can effectively improve the solvent resistance of HTLs without hindering hole transport, thereby enhancing the performance of QLED devices. Summary of the Invention

[0006] To address the challenge of existing HTL crosslinking technologies in simultaneously achieving good solvent resistance and hole transport performance, this invention provides a photoresist with enhanced carrier transport capabilities and its application. This photoresist comprises dithiobis(phenylazide) and 1,3,5-triynylbenzene components. The azide groups in the dithiobis(phenylazide) and the alkynyl groups in the 1,3,5-triynylbenzene can be crosslinked under ultraviolet light. By controlling the molar ratio and exposure dose, a complete photoresist pattern can be obtained after development. Using the composition comprising the above photoresist and hole transport layer material to fabricate the hole transport layer of a quantum dot light-emitting diode (QLED) not only effectively improves the solvent resistance of the hole transport layer but also promotes hole transport, reduces leakage current, and thus significantly enhances the performance of the QLED device.

[0007] Specifically, the following technical solutions are provided:

[0008] The first aspect of the present invention provides a photoresist comprising dithiobis(phenylazide) and 1,3,5-triynylbenzene; wherein the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the photoresist is (1:2)-(3:2), for example 1:2, 2:3, 1:1, 3:2, etc.

[0009] The photoresist provided by this invention contains dithiobis(phenylazide) and 1,3,5-triynylbenzene. The azide groups in the dithiobis(phenylazide) and the alkynyl groups in the 1,3,5-triynylbenzene can crosslink under ultraviolet light. The target photoresist pattern can be obtained through selective exposure and development. To ensure that the resulting pixel size is appropriate, the pattern is complete, and there is no crosstalk after exposure and development, the content of the two substances in the photoresist must be controlled within a suitable range. On the one hand, to ensure the formation of the crosslinked network, the azide groups need to be completely consumed, thus requiring an excess of alkynyl groups. One alkynyl group can react with one azide group; therefore, the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the photoresist must not exceed 3:2. Otherwise, the pixels formed after exposure and development will be too large, easily leading to crosstalk. Furthermore, the molar ratio should not be too small, for example, less than 1:2; otherwise, the pixels formed after exposure and development will be too small and the pattern incomplete. Therefore, the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the above photoresist needs to be controlled within the range of (1:2) to (3:2) to obtain a complete photoresist pattern while avoiding crosstalk problems.

[0010] Furthermore, the photoresist also contains a solvent selected from one or more of chlorobenzene, toluene, and chloroform.

[0011] Furthermore, the concentration of dithiobis(phenylazide) in the photoresist is 1-3 mg / mL, for example, 2 mg / mL; the concentration of dithiobis(phenylazide) in the photoresist refers to the ratio of the mass of dithiobis(phenylazide) to the volume of the solvent.

[0012] Furthermore, the preparation of the photoresist includes the following steps: mixing dithiobis(phenylazide), 1,3,5-triynylbenzene with a solvent to obtain the photoresist.

[0013] Furthermore, the photoresist is used to prepare a photoresist pattern through spin coating, exposure, and development; preferably, the exposure is performed under ultraviolet light irradiation, the wavelength of the ultraviolet light is preferably 365 nm, and the exposure dose is preferably 45 mJ / cm². 2 - 450mJ / cm 2 If the exposure dose is too low, the cross-linking degree will be insufficient, resulting in an incomplete pattern after development. If the exposure dose is too high, overexposure will occur, leading to a larger pattern area. Preferably, the exposure dose is controlled at 45 mJ / cm². 2 -450 mJ / cm 2 Within the range.

[0014] A second aspect of the present invention provides a composition for a hole transport layer, comprising the photoresist and hole transport material described in the first aspect.

[0015] Furthermore, the hole transport material is preferably TFB.

[0016] Furthermore, the mass ratio of hole transport material to 1,3,5-triynylbenzene in the hole transport layer composition is (4:1) to (24:1).

[0017] Furthermore, the hole transport layer composition further comprises a solvent selected from one or more of chlorobenzene, toluene, and chloroform.

[0018] Furthermore, the concentration of the hole transport material in the hole transport layer composition is 6-10 mg / mL, for example, 8 mg / mL; the concentration of the hole transport material in the hole transport layer composition refers to the ratio of the mass of the hole transport material to the volume of the solvent.

[0019] Furthermore, the preparation of the hole transport layer composition includes the following steps: dissolving the hole transport material in a solvent to obtain a first solution; adding photoresist to the first solution and mixing evenly to obtain the hole transport layer composition.

[0020] A third aspect of the present invention provides the application of the hole transport layer composition described in the second aspect in the fabrication of quantum dot light-emitting diodes.

[0021] Furthermore, the quantum dot light-emitting diode includes a transparent electrode, a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and a metal electrode stacked sequentially; wherein, the preparation of the hole transport layer includes the following steps: spin-coating the hole transport layer composition onto the side of the hole injection layer away from the transparent electrode, and then performing exposure and annealing treatments sequentially to obtain the hole transport layer.

[0022] Furthermore, ultraviolet light with a wavelength of 365 nm is used for exposure treatment; the preferred dose of the exposure treatment is 45 mJ / cm². 2 - 450 mJ / cm 2 .

[0023] Furthermore, the annealing temperature is preferably 130-150 °C, and the time is preferably 10-20 min, for example, annealing at 140 °C for 15 min.

[0024] Furthermore, the hole transport layer comprises a framework network formed by crosslinking dithiobis(phenylazide) with 1,3,5-triyneylbenzene and a hole transport material confined within the framework network.

[0025] This invention utilizes a composition comprising the aforementioned photoresist and hole transport material to prepare the hole transport layer of a quantum dot light-emitting diode. During the exposure process, since the azide group is more likely to undergo a cycloaddition reaction with alkynes than an insertion reaction with CH, the reaction between dithiobis(phenylazide) and 1,3,5-triynylbenzene (the azide group in dithiobis(phenylazide) acts as a 1,3-dipolar and undergoes a cycloaddition reaction with the dipolarophile molecule alkyne (1,3,5-triynylbenzene)) dominates the formation of the hole transport layer. The specific reaction principle is as follows: During the reaction, electrons transfer from the highest occupied molecular orbital (HOMO) of the azide group to the lowest unoccupied molecular orbital (LUMO) of the alkyne group. The terminal N atom of the dithiobis(phenylazide) acts as a nucleophilic acceptor and reacts with the C≡C triple bond of 1,3,5-triynylbenzene to form a CN bond. Simultaneously, the NN double bond breaks, forming NN and CN bonds, ultimately forming a pentagonal heterocyclic structure. The framework structure formed by the cross-linking of dithiobis(phenylazide) and 1,3,5-triynylbenzene in the hole transport layer confines the hole transport material within the framework structure in an orderly manner, forming a highly ordered continuous transport channel, thereby effectively promoting hole transport.

[0026]

[0027] Furthermore, by controlling the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the composition (the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene is preferably (1:2)-(3:2), for example 2:3) and the exposure dose during the hole transport layer preparation process (the exposure dose is preferably 45 mJ / cm²), the method can achieve further improvements. 2 - 450 mJ / cm 2 For example, 225 mJ / cm 2 This ensures that the azide groups react as uniformly as possible with alkynes rather than with the CH in TFB, thereby confining TFB in an orderly manner within the framework network formed by the crosslinking of dithiobis(phenylazide) and 1,3,5-triynylbenzene, maximizing the preservation of TFB's hole transport performance.

[0028] The beneficial effects of this invention are:

[0029] This invention provides a photoresist comprising dithiobis(phenylazide) and 1,3,5-triynylbenzene components, which can be cross-linked under ultraviolet light, and a complete photoresist pattern is obtained after development. The composition formed by the above photoresist and hole transport material can be used to prepare the hole transport layer of quantum dot light-emitting diodes, and the hole transport layer can be patterned by selective exposure and development; more importantly, the dithiobis(phenylazide), 1,3,5-triynylbenzene and hole transport material in the composition form a hole transport layer with a specific microstructure after exposure treatment, which can not only effectively improve the solvent resistance of the hole transport layer, but also promote hole transport, reduce the leakage current of the device, and obtain a high-performance QLED device. Attached Figure Description

[0030] Figure 1 The photoresist patterns prepared using different photoresists in Example 1;

[0031] Figure 2 The photoresist patterns prepared using different exposure doses in Example 1;

[0032] Figure 3 This is a reaction mechanism diagram of the hole transport layer preparation using the hole transport layer composition of the present invention;

[0033] Figure 4 The current density-voltage relationship diagrams are shown for the single-hole devices 1 and 2 prepared in Example 2 and the single-hole device prepared in Comparative Example 1.

[0034] Figure 5 The current density-voltage relationship is shown in the diagram of the single-hole device 1 prepared in Example 2 and the single-hole devices prepared in Comparative Examples 1 and 2.

[0035] Figure 6The current density-voltage-brightness curves are for the QLED devices prepared in Example 2 and Comparative Example 1. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms “comprising” or “including” used in this invention may also be replaced with the closed form “is” or “consisting of”.

[0038] In this invention, unless otherwise specified, all equipment and raw materials are available from the market or commonly used in the industry. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0039] Example 1: This example relates to a photoresist and the preparation of its pattern, as detailed below:

[0040] Preparation of photoresist 1: Dissolve 4 mg of dithiobis(phenylazide) in 8 mL of chlorobenzene and stir until completely dissolved. Then add 6 mg of 1,3,5-triynylbenzene and stir. Filter to obtain photoresist 1. The molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in photoresist 1 is 1:3.

[0041] Preparation of photoresist 2: Dissolve 4 mg of dithiobis(phenylazide) in 8 mL of chlorobenzene and stir until completely dissolved. Then add 4 mg of 1,3,5-triynylbenzene and stir. Filter to obtain photoresist 2. The molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in photoresist 2 is 1:2.

[0042] Preparation of photoresist 3: Dissolve 4 mg of dithiobis(phenylazide) in 8 mL of chlorobenzene and stir until completely dissolved. Then add 1.3 mg of 1,3,5-triynylbenzene and stir. Filter to obtain photoresist 4. The molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in photoresist 4 is 3:2.

[0043] Preparation of photoresist 4: Dissolve 4 mg of dithiobis(phenylazide) in 8 mL of chlorobenzene and stir until completely dissolved. Then add 1 mg of 1,3,5-triynylbenzene and stir. Filter to obtain photoresist 4. The molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in photoresist 4 is 2:1.

[0044] Photoresist patterns were prepared using the above-mentioned photoresists, and the preparation methods are as follows:

[0045] Photoresist was spin-coated into a film, and the photoresist film was selectively exposed using 365 nm ultraviolet light. The exposure dose was controlled, and the photoresist pattern was obtained after development with chlorobenzene.

[0046] (1) Photoresist patterns were prepared using different photoresists, with an exposure dose of 120 mJ / cm. 2 All other conditions are the same.

[0047] Photoresist patterns prepared from different photoresists, such as Figure 1 As shown in the figure, the photoresist pattern formed by photoresist 1 is incomplete; the photoresist patterns formed by photoresists 2 and 3 are complete; the photoresist pattern formed by photoresist 4 has excessively large pixels, resulting in crosstalk. Therefore, to obtain a complete photoresist pattern, the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the photoresist needs to be controlled within a suitable range, such as between 1:2 and 3:2.

[0048] (2) Using different exposure doses (15 mJ / cm) 2 45 mJ / cm 2 450 mJ / cm 2 525 mJ / cm 2 The photoresist pattern was prepared under the same conditions as the others.

[0049] Photoresist patterns prepared from photoresist 2 using different exposure doses, such as... Figure 2 As shown in the figure, the exposure dose is 15 mJ / cm². 2 The formed photoresist pattern exhibits edge defects after development due to insufficient cross-linking; the exposure dose is 45 mJ / cm. 2 450 mJ / cm 2 The resulting photoresist pattern was intact after development due to a moderate exposure dose; the exposure dose was 525 mJ / cm. 2 The resulting photoresist pattern has imperfections at the edges after development, resulting in overexposure.

[0050] Example 2: This example relates to the fabrication of a photoresist, a hole transport layer composition, a single-hole device, and a quantum dot light-emitting diode, as detailed below:

[0051] Preparation of photoresist: 4 mg of dithiobis(phenylazide) and 3 mg of 1,3,5-triynylbenzene were dissolved in 2 mL of chlorobenzene and stirred for about 3 h until homogeneous to obtain a photoresist solution. The molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the photoresist was 2:3.

[0052] Preparation of hole transport layer composition 1: 24 mg TFB was dissolved in 1 mL of chlorobenzene and completely dissolved to obtain a first solution; the first solution was mixed with a photoresist solution to obtain hole transport layer composition 1.

[0053] Fabrication of single-hole device 1: PEDOT:PSS was spin-coated as a hole injection layer on a cleaned and UV-treated ITO glass substrate, and annealed at 140 °C for 15 min. Next, hole transport layer composition 1 was spin-coated in a nitrogen-filled glove box, and annealed at 140 °C for 15 min to form a hole transport layer. Then, a QDs layer (purchased from Hefei Funa Technology, CdSe / ZnS) was spin-coated, and edge-wiping was performed. Subsequently, MoO3 and Al electrodes were sequentially deposited to prepare single-hole device 1.

[0054] Fabrication of single-hole device 2: PEDOT:PSS was spin-coated as a hole injection layer on a cleaned and UV-treated ITO glass substrate, and annealed at 140 °C for 15 min; then, hole transport layer composition 1 was spin-coated in a nitrogen-filled glove box and exposed to 365 nm UV light (exposure dose of 225 mJ / cm²). 2 After annealing at 140 °C for 15 min, a hole transport layer was formed; then, a QDs layer was spin-coated and the edges were wiped clean. Subsequently, MoO3 and Al electrodes were deposited sequentially to prepare a single-hole device 2.

[0055] The only difference between single-hole device 1 and single-hole device 2 is that the hole transport layer prepared by single-hole device 1 is not photocrosslinked, while the hole transport layer prepared by single-hole device 2 is photocrosslinked.

[0056] Fabrication of quantum dot light-emitting diodes (QLEDs): ITO wafers were sequentially cleaned with deionized water, anhydrous ethanol, and isopropanol, followed by UV sonication for 20 minutes. A PEDOT:PSS solution was then spin-coated at 4000 rpm for 45 seconds, followed by heating at 140 °C for 15 minutes to form a hole injection layer. Subsequently, the hole transport layer composition 1 (3000 rpm, 45 seconds) was spin-coated onto the surface of the hole injection layer, and exposed to 365 nm UV light (exposure dose of 225 mJ / cm²). 2 After annealing at 140 °C for 15 min, a hole transport layer was formed. QDs (quantum dot light-emitting layers) were spin-coated onto the hole transport layer surface (2000 rpm, 35 s), and allowed to stand for a short time to allow the solvent to evaporate, forming a quantum dot light-emitting layer. ZnMgO was then spin-coated onto the quantum dot light-emitting layer surface (2000 rpm, 35 s), and annealed at 120 °C for 15 min to form an electron transport layer. After preparation, edge wiping was performed. Then, the spin-coated device was placed in an evaporator to evaporate the Al electrode, obtaining the QLED device.

[0057] Comparative Example 1: This comparative example relates to the fabrication of a single-hole device and a quantum dot light-emitting diode. The difference from Example 1 is that the hole transport layer of the single-hole device and quantum dot light-emitting diode is directly fabricated using the hole transport material TFB, as detailed below:

[0058] Preparation of hole transport material solution: Weigh 8 mg of TFB and dissolve it in 1 mL of CB. The hole transport material solution is obtained after complete dissolution.

[0059] Preparation of single-hole device: The only difference from the preparation of single-hole device 1 in Example 1 is that an equal amount of hole transport material solution is used to replace the hole transport layer composition 1. All other operations are the same, and the corresponding single-hole device is prepared.

[0060] QLED fabrication: The only difference from the QLED fabrication in Example 1 is that an equal amount of hole transport material solution is used instead of composition 1 for the hole transport layer, and the exposure treatment step is not included. All other operations are the same, and the corresponding QLED device is prepared.

[0061] Comparative Example 2: This comparative example relates to a hole transport layer composition 2 and the preparation of a single hole device. The difference from Example 1 is that 1,3,5-trivinylbenzene is used in place of 1,3,5-triynylbenzene in equal molar amounts. All other aspects are the same, and a corresponding single hole device without photocrosslinking treatment is prepared.

[0062] Test Example 1: (1) Effect of photoresist and exposure treatment on hole transport performance of hole transport layer

[0063] At the same voltage, the higher the current density of a single-hole device, the better its hole transport performance.

[0064] Figure 4 The figure shows the current density-voltage relationship of single-hole devices 1 and 2 prepared in Example 2 and the single-hole device prepared in Comparative Example 1. As can be seen from the figure, compared to the single-hole device prepared in Comparative Example 1 using only TFB to prepare the hole transport layer, the single-hole device 1 prepared by introducing photoresist into the hole transport layer has a higher current density, and the current density of the single-hole device can be further improved by exposure treatment. Therefore, it can be seen that introducing photoresist into the hole transport layer can effectively promote hole transport, and the hole transport performance can be further improved by exposing the hole transport layer prepared with introduced photoresist.

[0065] (2) Effect of different additives on hole transport performance of hole transport layer

[0066] Figure 5The figure shows the current density-voltage relationship of the single hole device 1 prepared in Example 2, and the single hole devices prepared in Comparative Example 1 and Comparative Example 2. As can be seen from the figure, the simultaneous introduction of dithiobis(phenylazide) and 1,3,5-trivinylbenzene into the hole transport layer will degrade the hole transport performance of the device.

[0067] Test Example 2: Performance tests were conducted on the QLED devices prepared in Example 2 and Comparative Example 1. The test results are as follows: Figure 6 As shown in the figure, after the device is lit, the luminous brightness of Example 2 is comparable to that of Comparative Example 1. However, the overall current density of the QLED device prepared in Example 2 is always lower than that of Comparative Example 1. Therefore, it can be seen that the strategy of preparing the hole transport layer by using a composition containing photoresist in Example 2 can effectively suppress the leakage current of the device, so that the prepared QLED device has higher electroluminescence efficiency.

[0068] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A photoresist, characterized in that, The photoresist comprises dithiobis(phenylazide) and 1,3,5-triynylbenzene; the molar ratio of dithiobis(phenylazide) to 1,3,5-triynylbenzene in the photoresist is (1:2) to (3:2).

2. The photoresist according to claim 1, characterized in that, The photoresist further comprises a solvent, wherein the solvent is selected from one or more of chlorobenzene, toluene, and chloroform; The concentration of dithiobis(phenylazide) in the photoresist is 1-3 mg / mL.

3. A composition for a hole transport layer, characterized in that, It includes the photoresist and hole transport material as described in claim 1 or 2.

4. The composition for a hole transport layer according to claim 3, characterized in that, The hole transport material is TFB; The mass ratio of hole transport material to 1,3,5-triynylbenzene in the composition for hole transport layer is (4:1) to (24:1).

5. The composition for a hole transport layer according to claim 3, characterized in that, The hole transport layer composition further comprises a solvent selected from one or more of chlorobenzene, toluene, and chloroform; The concentration of the hole transport material in the composition for the hole transport layer is (6-10) mg / mL.

6. The composition for a hole transport layer according to claim 3, characterized in that, The preparation of the hole transport layer composition includes the following steps: dissolving the hole transport material in a solvent to obtain a first solution; adding photoresist to the first solution and mixing evenly to obtain the hole transport layer composition.

7. The use of a hole transport layer composition as described in any one of claims 3-6 in the fabrication of a quantum dot light-emitting diode.

8. The application according to claim 7, characterized in that, The quantum dot light-emitting diode includes a transparent electrode, a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and a metal electrode stacked sequentially. The hole transport layer is prepared by the following steps: spin-coating the hole transport layer composition onto the side of the hole injection layer away from the transparent electrode, and then performing exposure and annealing treatments in sequence to obtain the hole transport layer.

9. The application according to claim 8, characterized in that, Exposure treatment was performed using ultraviolet light with a wavelength of 365 nm; the dose of the exposure treatment was 45 mJ / cm². 2 - 450 mJ / cm 2 .

10. The application according to claim 8, characterized in that, The annealing process is performed at a temperature of 130-150 ℃ for 10-20 min.

Images