Photoetching patterned quantum dot and preparation method of quantum dot full-color overlay device

Abstract

The invention relates to the technical field of quantum dot display, in particular to a photoetching patterning quantum dot and a preparation method of a quantum dot full-color overlay device. It can be understood that according to the technical scheme provided by the invention, the novel photosensitizer developed by the invention effectively solves the bottleneck problem of a traditional photoresist method in quantum dot patterning, and the efficiency and quality of photoetching and patterning quantum dots are improved; the quantum dots can be dispersed in a green solvent PGMEA through ligand exchange, and the requirements of environmental friendliness and future mass production are met; blue quantum dot pixel patterning is achieved, the method can be popularized to preparation of a full-color quantum dot overlay device, the method has important significance in the technical field of quantum dot display, and further development and industrial application of the quantum dot display technology are promoted.

Description

Technical Field

[0001] The present application relates to the field of quantum dot display technology, and in particular to a method for preparing photolithography patterned quantum dots and quantum dot full-color overlay devices. Background Art

[0002] Quantum dot light-emitting diode display (QLED), as a new display technology developed based on organic light-emitting display (OLED), has the advantages of high color saturation, wide color gamut, narrow luminescence peak and good stability. With the continuous advancement of quantum dot technology, its quantum efficiency has gradually increased and has approached the level of industrialization. Photolithography is quite mature in integrated circuit processing, but traditional photoresist methods face many bottlenecks in quantum dot patterning applications, such as complex and cumbersome process flow and poor solvent compatibility. In addition, the current blue quantum dot electroluminescence efficiency is low and unstable, and the efficiency further decreases after exposure by an exposure machine and development with a developer, which greatly limits the application of photolithography in the field of quantum dot display. Therefore, there is an urgent need to develop new, efficient and soft photosensitizers to achieve full-color quantum dot patterning. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a method for preparing photolithography patterned quantum dots and quantum dot full-color overlay devices to solve at least one problem existing in the prior art.

[0004] According to a first aspect of an embodiment of the present invention, a method for photolithographically patterning quantum dots is provided, the method comprising:

[0005] The pre-treated quantum dots are obtained by using a preset ligand exchange method; wherein the pre-treated quantum dots include: BQD-MMES quantum dots, RQD-MMES quantum dots, and GQD-MMES quantum dots;

[0006] Using the pretreated quantum dots and a preset photosensitizer, after the carbon-carbon double bonds of the ligands on the surface of the quantum dots are illuminated by the preset photosensitizer to generate free radicals to capture methylene hydrogen atoms to form methylene free radicals, the methylene free radicals are used to initiate a polymerization reaction of the carbon-carbon double bonds, so that the ligands MMES on the surface of the color quantum dots are cross-linked, the solubility is reduced, the solubility of the non-exposed area remains unchanged, and a pattern is formed by developing with a developer;

[0007] The preset upright device structure is used to realize photolithographic patterning of quantum dots. Further, the method of obtaining pre-treated quantum dots by using a preset ligand exchange method includes:

[0008] The blue quantum dots BQD-OA with oleic acid ligands were dispersed in octane, and an excess of mono[2-[(2-methyl-acryloyl)oxy]ethyl]succinate (MMES) was added to precipitate the successfully exchanged BQD-MMES in octane. After centrifugation and drying, the BQD-MMES was redissolved in the green solvent PGMEA.

[0009] Furthermore, the method of using a preset upright device structure to realize photolithographic patterning of quantum dots includes:

[0010] Using an upright device structure, PEDOT layer and HT layer were spin-coated on the PM substrate in sequence, and BQD-MMES quantum dots were spin-coated on the HT layer;

[0011] After adding photosensitizer, spin-coat the film, expose it with an exposure machine, develop it with PGMEA solution, and dry it;

[0012] The ZnMgO electron transport layer was spin-coated and the electrodes were evaporated and packaged. The device efficiency and current density parameters of the photolithographic BQD-MMES were tested to realize photolithographic patterning of quantum dots.

[0013] Furthermore, the steps of preparing the preset photosensitizer include:

[0014] A raw material of benzophenone with phenolic hydroxyl, carboxyl or fluorine atom is selected, and a tertiary amine structure is introduced through esterification, amidation or nucleophilic substitution reaction. The raw material is modified to introduce multiple reaction sites, thereby obtaining a multi-substituted benzophenone derivative.

[0015] According to a second aspect of an embodiment of the present invention, a method for preparing a quantum dot full-color overlay device is provided, which is applied to any one of the above-mentioned methods for patterning quantum dots by lithography, comprising:

[0016] Spin coating an electron transport layer on a PM substrate; wherein the electron transport layer uses a ZnO solution with a concentration of 30 mg / mL, a rotation speed of 2500 rpm, and a film thickness of 20-30 nm;

[0017] Spin-coat RQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , and then developed with PGMEA; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm;

[0018] Spin-coat GQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2, and then developed with PGMEA; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm;

[0019] Spin-coat BQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , then developed with PGMEA to obtain full-color quantum dot engraved pixels; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm;

[0020] The full-color quantum dots are used to overlay pixels, and the device structure is obtained by evaporating HT, HI and electrodes and encapsulating them.

[0021] Furthermore, the photosensitizer in the RQD-MMES-P1, GQD-MMES-P1 and BQD-MMES-P1 is the preset photosensitizer described in claim 1.

[0022] Furthermore, a photolithography-patterned quantum dot product is prepared by the method for photolithography-patterned quantum dots described in any one of the above items.

[0023] Furthermore, the quantum dot full-color overlay device product is prepared by the preparation method of the quantum dot full-color overlay device described in any of the above items.

[0024] It can be understood that the technical solution provided by the present invention obtains pre-treated quantum dots by utilizing a preset ligand exchange method; wherein the quantum dots include: BQD-MMES quantum dots, RQD-MMES quantum dots, and GQD-MMES quantum dots; utilizing the pre-treated BQD-MMES quantum dots and a preset photosensitizer, utilizing the carbon-carbon double bonds of the surface ligands of the quantum dots to generate free radicals under the illumination of the preset photosensitizer to capture methylene hydrogen atoms to form methylene free radicals, and utilizing the methylene free radicals to initiate a carbon-carbon double bond polymerization reaction, so that the surface ligands MMES of the color quantum dots are cross-linked, the solubility is reduced, the solubility of the non-exposed area remains unchanged, and a pattern is formed after development with a developer; wherein the color quantum dots include: blue quantum dots, green quantum dots, and red quantum dots; a preset upright device structure is adopted to realize photolithographic patterning of quantum dots. It can be understood that the technical solution provided by the present invention and the new photosensitizer developed in this application effectively solve the bottleneck problem of the traditional photoresist method in quantum dot patterning, and improve the efficiency and quality of photolithography patterned quantum dots; through ligand exchange, the quantum dots can be dispersed in the green solvent PGMEA, which meets the requirements of environmental friendliness and future mass production; blue quantum dot pixel patterning is achieved and can be extended to the preparation of full-color quantum dot overlay devices, which is of great significance in the field of quantum dot display technology and will help promote the further development and industrial application of quantum dot display technology.

[0025] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0027] Figure 1 is a schematic diagram of steps of a method for photolithography patterning quantum dots according to an exemplary embodiment;

[0028] Figure 2 It is a flow chart of a method for preparing a quantum dot full-color overlay device according to an exemplary embodiment;

[0029] Figure 3 is a schematic diagram of blue quantum dot ligand exchange according to an exemplary embodiment;

[0030] Figure 4 is a schematic diagram showing the photosensitization mechanism and oxygen inhibition mechanism of benzophenone and thioxanthone according to an exemplary embodiment;

[0031] Figure 5 is a structural formula of a photosensitizer according to an exemplary embodiment;

[0032] Figure 6 is a photosensitizer molecular formula showing absorption at 365 nanometers according to an exemplary embodiment;

[0033] Figure 7 is a schematic diagram of a blue quantum dot patterning mechanism according to an exemplary embodiment;

[0034] Figure 8 is a diagram showing the effect of blue quantum dot patterning and a schematic diagram of a device structure according to an exemplary embodiment;

[0035] Fig. 9 is a schematic diagram of photolithographic patterning of RQD-MMES and GQD-MMES quantum dots according to an exemplary embodiment;

[0036] Fig.10 It is a schematic diagram of the preparation process of a quantum dot full-color overlay device according to an exemplary embodiment. DETAILED DESCRIPTION

[0037] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0038] Embodiment 1

[0039] See also Figure 1 , Figure 1 1 is a schematic diagram of the steps of a method for photolithographic patterning of quantum dots according to an exemplary embodiment, the method comprising:

[0040] S1. Obtaining pretreated quantum dots using a preset ligand exchange method; wherein the pretreated quantum dots include: BQD-MMES quantum dots, RQD-MMES quantum dots, and GQD-MMES quantum dots;

[0041] S2. Using the pretreated quantum dots and the preset photosensitizer, the carbon-carbon double bonds of the ligands on the surface of the quantum dots are used to generate free radicals under the illumination of the preset photosensitizer to capture methylene hydrogen atoms to form methylene free radicals, and then the methylene free radicals are used to initiate a polymerization reaction of the carbon-carbon double bonds, so that the ligands MMES on the surface of the color quantum dots are cross-linked, the solubility is reduced, the solubility of the non-exposed area remains unchanged, and a pattern is formed by developing with a developer;

[0042] S3. Using a preset upright device structure to realize photolithographic patterning of quantum dots. Specifically, the method of obtaining pre-treated quantum dots using a preset ligand exchange method includes:

[0043] The blue quantum dots BQD-OA with oleic acid ligands were dispersed in octane, and an excess of mono[2-[(2-methyl-acryloyl)oxy]ethyl]succinate (MMES) was added to precipitate the successfully exchanged BQD-MMES in octane. After centrifugation and drying, the BQD-MMES was redissolved in the green solvent PGMEA.

[0044] Specifically, the method of using a preset upright device structure to realize photolithographic patterning of quantum dots includes:

[0045] Using an upright device structure, PEDOT layer and HT layer were spin-coated on the PM substrate in sequence, and BQD-MMES quantum dots were spin-coated on the HT layer;

[0046] After adding photosensitizer, spin-coat the film, expose it with an exposure machine, develop it with PGMEA solution, and dry it;

[0047] The ZnMgO electron transport layer was spin-coated and the electrodes were evaporated and packaged. The device efficiency and current density parameters of the photolithographic BQD-MMES were tested to realize photolithographic patterning of quantum dots.

[0048] Specifically, the steps for preparing the preset photosensitizer include:

[0049] A raw material of benzophenone with phenolic hydroxyl, carboxyl or fluorine atom is selected, and a tertiary amine structure is introduced through esterification, amidation or nucleophilic substitution reaction. The raw material is modified to introduce multiple reaction sites, thereby obtaining a multi-substituted benzophenone derivative.

[0050] In one embodiment, the present application successfully achieves the dispersion of quantum dots in the green solvent PGMEA through a unique ligand exchange method, which is not only beneficial to the subsequent processing of quantum dots, but also takes into account the environmental friendliness requirements of quantum dots in future large-scale production, and provides strong support for the sustainable development of quantum dot display technology.

[0051] The innovatively designed and synthesized high-efficiency and soft photosensitizer effectively solves the problems of complicated process flow and poor solvent compatibility encountered in the traditional photoresist method in the process of quantum dot patterning. At the same time, the photosensitizer can reduce the damage to quantum dots while increasing the rate of photopolymerization reaction, especially in the process of photolithography patterning of blue quantum dots, significantly improving its electroluminescence efficiency and stability, overcoming the problem of the decrease in electroluminescence efficiency of blue quantum dots after exposure and development in the prior art, and greatly promoting the application of photolithography in the field of quantum dot display.

[0052] See also Figure 2 , Figure 2 The present invention is a flow chart of a method for preparing a quantum dot full-color overlay device according to an exemplary embodiment, wherein the method comprises:

[0053] Spin coating an electron transport layer on a PM substrate; wherein the electron transport layer uses a ZnO solution with a concentration of 30 mg / mL, a rotation speed of 2500 rpm, and a film thickness of 20-30 nm;

[0054] Spin-coat RQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , and then developed with PGMEA; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm;

[0055] Spin-coat GQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , and then developed with PGMEA; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm;

[0056] Spin-coat BQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , then developed with PGMEA to obtain full-color quantum dot engraved pixels; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm;

[0057] The full-color quantum dots are used to overlay pixels, and the device structure is obtained by evaporating HT, HI and electrodes and encapsulating them.

[0058] It should be noted that the photosensitizer in the RQD-MMES-P1, GQD-MMES-P1 and BQD-MMES-P1 is the preset photosensitizer described in claim 1.

[0059] Furthermore, a photolithography-patterned quantum dot product is prepared by the method for photolithography-patterned quantum dots described in any one of the above items.

[0060] It should be noted that the quantum dot full-color overlay device product prepared by the preparation method of the quantum dot full-color overlay device described in any of the above items.

[0061] In one embodiment, the method for preparing a full-color quantum dot overlay device provided by the present invention successfully realizes the overlay of full-color quantum dots based on the precise control and processing of quantum dots of different colors (red, green, and blue), and prepares a high-quality full-color quantum dot display device. This achievement has laid a solid foundation for the further development of quantum dot display technology in the field of full-color display, and is expected to promote the widespread application of quantum dot display technology in the display market. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0064] Embodiment 1:

[0065] 1. Ligand exchange step:

[0066] See also Figure 3 , take a certain amount of blue quantum dots BQD-OA with oleic acid ligands, disperse them in an appropriate amount of octane solution, and stir evenly. Then, slowly add an excess of succinic acid mono[2-[(2-methyl-acryloyl)oxy]ethyl] ester (MMES), and continue stirring the reaction for a period of time. After the reaction is completed, collect the precipitate by centrifugation. Dry the precipitate under a vacuum environment to remove the residual octane solvent. Finally, dissolve the dried precipitate in PGMEA solvent to obtain a BQD-MMES quantum dot solution for later use.

[0067] 2. Photolithography patterning of BQD-MMES quantum dots:

[0068] 2.1 Design and synthesis of photosensitizers

[0069] See also Figure 4 , Figure 4 The molecular design of benzophenone was obtained by selecting benzophenone raw materials with phenolic hydroxyl groups, introducing tertiary amine structures through esterification, and further modifying and introducing multiple reaction sites to synthesize a multi-substituted benzophenone derivative. Its molecular structure was characterized to confirm that its structure met the design requirements and had good solubility in PGMEA solvent.

[0070] See also Figure 5 It should be noted that, when selecting raw materials of benzophenone with phenolic hydroxyl, carboxyl, or fluorine atom, the structure of tertiary amine is introduced through esterification, amidation, or nucleophilic substitution reaction. Based on this idea, the raw materials are modified to introduce multiple reaction sites, so that multi-substituted benzophenone derivatives can be obtained, such as di-, tri-, tetra-, hexa-, octa-, etc.

[0071] Benzophenone can also be replaced by thioxanthone (I TX), which has the same effect. However, the solubility of the photosensitizer in PGMEA also needs to be considered. According to the principle of like dissolves like, ester bonds, amide bonds, ether bonds and thioether bonds are preferred.

[0072] It should be noted that Figure 5 The structure on the right side is based on the benzo six-membered ring ketone structure on the left side, with a nitrogen-containing group connected to the appropriate position of the six-membered ring. The nitrogen-containing group has an R substituent, where the carbon chain lengths at R and N are variable, ranging from 2 carbon atoms to n carbon atoms, and the carbon chain length is not limited.

[0073] The absorption of the above benzophenone derivatives is mainly around 254nm. Since quantum dots have strong absorption at 254nm, when using a 254nm light source for photolithography, there is a certain degree of damage to the blue quantum dots, especially the quantum efficiency, which in turn affects the electroluminescent efficiency. Therefore, based on the above, it is necessary to red-shift the absorption of benzophenone derivatives to the ultraviolet light or even visible light region, and design benzophenone into a push-pull electron system. The electron-pushing groups that can be selected include: pyrrole, carbazole, triphenylamine, tertiary amine, phenothiazine, phenoxazine and other structures. Molecular design such as Figure 6 shown.

[0074] 2.2 Patterned blue quantum dots

[0075] See also Figure 7 , take an appropriate amount of the BQD-MMES quantum dot solution prepared above, add a certain amount of the synthesized photosensitizer, and mix thoroughly. Spin-coat the mixed solution on the PM substrate on which the PEDOT / HT layer has been prepared to form a thin film. Use a light source of a specific wavelength to expose the film for 20 seconds. After exposure, develop with PGMEA developer and observe the formation of the quantum dot pattern.

[0076] 2.3 Blue quantum dot patterning and device preparation

[0077] See also Figure 8 , Fig. 9, using a positive device structure, prepare the PM substrate, and then spin-coat the PEDOT layer and the HT layer. Considering the characteristics of charge transfer, the optimal thickness of these two layers is between 40-60nm and 20-30nm, respectively. Then spin-coat the BQD-MMES quantum dots on the HT layer, select the concentration of BQD-MMES as 25mg / mL, and the dispersing solvent is PGMEA. Add 1-4mg of the above photosensitizer to the quantum dots of BQD-MMES, mix evenly, and then spin-coat the film. The exposure machine performs alignment exposure for 10-30s. Then develop with PGMEA solution, and finally dry to observe the film layer of the blue quantum dots. Use a step meter to test the thickness of the remaining blue quantum dot film layer, and use an atomic force microscope to observe the quality of the film. In addition, continue to spin-coat ZnMgO (electron transport layer) and evaporate electrodes, and encapsulate. Test the device efficiency, current density and other parameters of the photolithographic BQD-MMES to evaluate the effect of the cross-linking agent on the performance of the BQD-MMES quantum dot device.

[0078] The same principle: red quantum dots (RQD-MMES) and green quantum dots (GQD-MMES) can be patterned, such as Fig. 9 shown.

[0079] Embodiment 2:

[0080] Preparation of Quantum Dot Full-Color Overlay Devices

[0081] See also Fig.10 Considering the stability of blue quantum dots, the last layer is made of blue quantum dots. Using an upright or inverted device structure, this article considers completing the overlay of three-color quantum dots on an inverted device structure. Spin coat the electron transport layer (ZnO solution) on the PM substrate with a concentration of 30 mg / mL and a rotation speed of 2500 rpm. The preferred film thickness is 20-30 nm. Then spin coat RQD-MMES-P1 (photosensitizer) with a concentration of 20-30 mg-0.5-1 mg / mL and a rotation speed of 2000 rpm. The preferred film thickness is 20-30 nm. Then expose it in position with an exposure dose of 10-300 mJ / cm 2 . Then develop in developer (PGMEA) for 30s-120s. Then spin-coat GQD-MMES-P1 with a concentration of 20-30mg-0.5-1mg / mL and a rotation speed of 2000rpm. The preferred film thickness is 20-30nm. Then expose it in position with an exposure dose of 10-300mJ / cm 2. Then develop in developer (PGMEA) for 30s-120s. Then spin-coat BQD-MMES-P1 with a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm. Then expose it in position with an exposure dose of 10-300mJ / cm2. Then develop in developer (PGMEA) for 30s-120s. Thus, full-color quantum dot engraved pixels are obtained. As shown in the schematic Figure 8 As shown. Finally, HT, HI and electrodes are evaporated and packaged to obtain the device structure. The current density and efficiency are tested. The device efficiency of RGB three-color quantum dots is observed.

[0082] It can be understood that the technical solution provided by the present invention and the new photosensitizer developed in this application effectively solve the bottleneck problem of the traditional photoresist method in quantum dot patterning, and improve the efficiency and quality of photolithography patterned quantum dots; through ligand exchange, the quantum dots can be dispersed in the green solvent PGMEA, which meets the requirements of environmental friendliness and future mass production; blue quantum dot pixel patterning is achieved and can be extended to the preparation of full-color quantum dot overlay devices, which is of great significance in the field of quantum dot display technology and will help promote the further development and industrial application of quantum dot display technology.

[0083] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0084] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0085] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0086] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0087] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0088] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0089] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0091] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for photolithographically patterning quantum dots, characterized in that: The method comprises: The pre-treated quantum dots are obtained by using a preset ligand exchange method; wherein the pre-treated quantum dots include: BQD-MMES quantum dots, RQD-MMES quantum dots, and GQD-MMES quantum dots; Using the pretreated quantum dots and a preset photosensitizer, after the carbon-carbon double bonds of the ligands on the surface of the quantum dots are illuminated by the preset photosensitizer to generate free radicals to capture methylene hydrogen atoms to form methylene free radicals, the methylene free radicals are used to initiate a polymerization reaction of the carbon-carbon double bonds, so that the ligands MMES on the surface of the color quantum dots are cross-linked, the solubility is reduced, the solubility of the non-exposed area remains unchanged, and a pattern is formed by developing with a developer; A preset upright device structure is used to realize photolithographic patterning of quantum dots.

2. The method according to claim 1, characterized in that The method of obtaining the pre-treated quantum dots by using a preset ligand exchange method comprises: The blue quantum dots BQD-OA with oleic acid ligands were dispersed in octane, and an excess of mono[2-[(2-methyl-acryloyl)oxy]ethyl]succinate (MMES) was added to precipitate the successfully exchanged BQD-MMES in octane. After centrifugation and drying, the BQD-MMES was redissolved in the green solvent PGMEA.

3. The method according to claim 1, characterized in that The method adopts a preset upright device structure to realize photolithographic patterning of quantum dots, including: Using an upright device structure, PEDOT layer and HT layer were spin-coated on the PM substrate in sequence, and BQD-MMES quantum dots were spin-coated on the HT layer; After adding photosensitizer, spin-coat the film, expose it with an exposure machine, develop it with PGMEA solution, and dry it; The ZnMgO electron transport layer was spin-coated and the electrodes were evaporated and packaged. The device efficiency and current density parameters of the photolithographic BQD-MMES were tested to realize photolithographic patterning of quantum dots.

4. The method according to claim 1, characterized in that: The steps for preparing the preset photosensitizer include: A raw material of benzophenone with phenolic hydroxyl, carboxyl or fluorine atom is selected, and a tertiary amine structure is introduced through esterification, amidation or nucleophilic substitution reaction. The raw material is modified to introduce multiple reaction sites, thereby obtaining a multi-substituted benzophenone derivative.

5. A method for preparing a quantum dot full-color overlay device, characterized in that: A method for photolithographically patterning quantum dots as claimed in any one of claims 1 to 4, the method comprising: Spin coating an electron transport layer on a PM substrate; wherein the electron transport layer uses a ZnO solution with a concentration of 30 mg / mL, a rotation speed of 2500 rpm, and a film thickness of 20-30 nm; Spin-coat RQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , and then developed with PGMEA; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm; Spin-coat GQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , and then developed with PGMEA; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm; Spin-coat BQD-MMES-P1 with a preset photosensitizer and expose it in position with an exposure dose of 10-300mJ / cm 2 , then developed with PGMEA to obtain full-color quantum dot engraved pixels; wherein the development time is 30s-120s; wherein the preset photosensitizer uses a concentration of 20-30mg-0.5-1mg / mL, a rotation speed of 2000rpm, and a preferred film thickness of 20-30nm; The full-color quantum dots are used to overlay pixels, and the device structure is obtained by evaporating HT, HI and electrodes and encapsulating them.

6. The method for preparing a quantum dot full-color overlay device according to claim 5, characterized in that: The photosensitizer in the RQD-MMES-P1, GQD-MMES-P1 and BQD-MMES-P1 is the preset photosensitizer described in claim 1.

7. A photolithography-patterned quantum dot product prepared by the method for photolithography-patterned quantum dots according to any one of claims 1 to 4.

8. A quantum dot full-color overlay device product prepared by the method for preparing a quantum dot full-color overlay device as described in any one of claims 5 to 6.

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