A core-shell structure perovskite quantum dot, a perovskite quantum dot negative photoresist and a preparation method and application thereof
By forming an ordered double-shell structure on perovskite quantum dots, the stability and monodispersity issues of perovskite photoresist are solved, resulting in a photoresist with high stability and high luminous efficiency, suitable for applications such as MicroLED, flexible optoelectronic devices, and environmental sensing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-19
AI Technical Summary
Existing perovskite quantum dot photoresists are unstable in humid environments, have poor optical stability and monodispersity, and have complex synthesis processes, which affects their application in various fields.
By employing a core-shell structured perovskite quantum dot and using a room-temperature structure transformation strategy based on ligand post-treatment, an ordered double-shell structure is formed, achieving high water stability and monodispersity of the perovskite quantum dot, and preparing a photoresist with high stability and high luminescence efficiency.
This study achieves high stability and high luminous efficiency in perovskite quantum dot photoresists, simplifies the synthesis process, improves photolithography precision and application versatility, and is suitable for fields such as MicroLED, flexible optoelectronic devices and environmental sensing.
Smart Images
Figure CN121406316B_ABST
Abstract
Description
Technical Field
[0001] This application relates to a core-shell structured perovskite quantum dot, a perovskite quantum dot negative photoresist, its preparation method and application, belonging to the field of nanomaterials technology. Background Technology
[0002] Perovskite quantum dots (HPNCs) have become a research hotspot due to their excellent photoelectric properties (such as high photoluminescence quantum yield and narrow emission bandwidth). However, they are extremely unstable in humid environments, which means that the perovskite photoresists prepared from them require aqueous development during use. This characteristic severely limits the application of perovskite photoresists in various fields and has become a pain point in the industry. In the existing technology, the stability can be partially improved by encapsulation with oxides, polymers or metal sulfides, but the following problems still exist: (1) the optical stability of the quantum dot photoresist products is poor, making it difficult to meet the conditions for commercialization; (2) the monodispersity is poor, which affects the photolithography accuracy of perovskite photoresists; (3) the synthesis process is complicated, for example, the core-shell structure requires multiple pretreatment steps. Summary of the Invention
[0003] To address the aforementioned technical problems in existing technologies for perovskite quantum dot negative photoresists, this application proposes a core-shell structured perovskite quantum dot and a novel perovskite quantum dot negative photoresist technology. Based on a room-temperature structure transformation strategy using ligand post-processing, an in-situ core-shell structure is formed to achieve high water stability and monodispersity of perovskite quantum dots, thereby preparing a perovskite quantum dot photoresist (HPNC-PR) with high stability and high luminous efficiency.
[0004] The technical solution adopted in this application is as follows:
[0005] According to a first aspect of this application, a core-shell perovskite quantum dot is provided, wherein the core is a CsPbX3 perovskite quantum dot and the shell is OAm. + Through electrostatic interaction with [PbX4] 2- They combine to form an ordered double shell;
[0006] X is selected from one of Cl, Br, and I, OAm + It is an oleylamine cation.
[0007] Optionally, the shell is generated by in-situ self-assembly of perovskite quantum dots after treatment with OAmX ligands.
[0008] Optionally, the ordered double-layer shell is OAm. + / [PbX4] 2- / OAm + structure.
[0009] According to a second aspect of this application, a method for preparing core-shell structured perovskite quantum dots is provided, comprising the following steps:
[0010] S1. Provide CsPbX3 nanocrystal solution;
[0011] S2. Add OAmX treatment solution to the CsPbX3 nanocrystal solution, react, wash, separate and dry the reaction product to obtain product powder;
[0012] S3. Disperse the product powder in a system containing a polar solvent to obtain perovskite quantum dots with a core-shell structure.
[0013] Optionally, in step S1, the CsPbX3 nanocrystal solution is filtered through 0.2μm PTFE.
[0014] Optionally, in step S1, the average size of the CsPbX3 nanocrystals is 14~17 nm.
[0015] Optionally, in step S2, the molar ratio of the OAmX to the CsPbX3 nanocrystals is 1000~29000:1.
[0016] Optionally, in step S2, the molar ratio of the OAmX to the CsPbX3 nanocrystals is selected from any value or a range between 1000:1, 2000:1, 3000:1, 4000:1, 5000:1, 6000:1, 7000:1, 8000:1, 9000:1, 10000:1, 15000:1, 20000:1, 25000:1, and 29000:1.
[0017] Optionally, in step S2, the reaction conditions include: the reaction is carried out under stirring conditions, the reaction temperature is 20~35°C, and the reaction time is 1~3h.
[0018] Optionally, in step S3, the polar solvent is propylene glycol methyl ether acetate (PGMEA).
[0019] According to a third aspect of this application, a perovskite quantum dot negative photoresist is provided, comprising a negative photoresist and core-shell structured perovskite quantum dots;
[0020] The core is a CsPbX3 perovskite quantum dot, and the shell is an OAm. + Through electrostatic interaction with [PbX4] 2- They combine to form an ordered double shell;
[0021] X is selected from one of Cl, Br, and I, OAm + It is an oleylamine cation.
[0022] Optionally, the shell is generated by in-situ self-assembly of the perovskite quantum dot surface after treatment with OAmX ligands. That is, the three-dimensional (3D) CsPbX3 perovskite quantum dots are induced to transform into a zero-dimensional (0D) structure through OAmX ligand post-treatment, and a core-shell structure is formed in-situ in a polar solvent.
[0023] Optionally, the ordered double-layer shell is OAm. + / [PbX4] 2- / OAm + structure.
[0024] According to a fourth aspect of this application, a method for preparing the above-mentioned perovskite quantum dot negative photoresist is provided, comprising the following steps:
[0025] S1. Provide CsPbX3 nanocrystal solution;
[0026] S2. Add OAMX (oleylamine halide) treatment solution to the CsPbX3 nanocrystal solution, react, and wash, separate and dry the reaction product to obtain product powder;
[0027] S3. Disperse the product powder in a system containing negative photoresist to obtain the perovskite quantum dot negative photoresist.
[0028] Optionally, in step S1, the CsPbX3 nanocrystal solution is filtered through 0.2μm PTFE.
[0029] Optionally, in step S1, the average size of the CsPbX3 nanocrystals is 14~17 nm.
[0030] Optionally, in step S2, the molar ratio of the OAmX to the CsPbX3 nanocrystals is 1000~29000:1.
[0031] Optionally, in step S2, the molar ratio of the OAmX to the CsPbX3 nanocrystals is selected from any value or a range between 1000:1, 2000:1, 3000:1, 4000:1, 5000:1, 6000:1, 7000:1, 8000:1, 9000:1, 10000:1, 15000:1, 20000:1, 25000:1, and 29000:1.
[0032] Optionally, in step S2, the reaction conditions include: the reaction is carried out under stirring conditions, the reaction temperature is 20~35°C, and the reaction time is 1~3h.
[0033] Optionally, in step S3, the negative photoresist is selected from at least one of g / i line negative photoresist, KrF negative photoresist, and ArF negative photoresist.
[0034] Optionally, in step S3, the system containing the negative photoresist is a system containing a polar solvent. For example, the polar solvent is propylene glycol methyl ether acetate (PGMEA).
[0035] According to a fifth aspect of this application, at least one of the following is provided for use in the fabrication of MicroLEDs, quantum light sources, environmental sensing, and solar energy: the perovskite quantum dot with the core-shell structure described above, the perovskite quantum dot with the core-shell structure obtained by the above preparation method, the perovskite quantum dot negative photoresist described above, and the perovskite quantum dot negative photoresist prepared by the above preparation method.
[0036] The beneficial effects of this application include:
[0037] The perovskite quantum dot negative photoresist preparation method provided in this application can achieve high stability in a one-step process at room temperature without pre-encapsulation, simplifying the process compared to existing technologies and facilitating mass production. In the prepared perovskite quantum dot negative photoresist, the oil-based ammonium salt (OAmX) acts as a ligand with a natural affinity for the PMA (methacrylate monomer) system photoresist. The perovskite can be dispersed as nanoparticles in the photoresist, significantly improving lithography precision. The resulting perovskite quantum dot photoresist has a linewidth ≤2μm, a photoluminescence quantum yield (PLQY) >80%, and water stability >10,000 hours. It has wide applications, suitable for MicroLED, flexible optoelectronic devices, environmental sensing, solar energy, and other fields. Attached Figure Description
[0038] Figure 1(a) shows the structural transformation from 3D CsPbBr3 to 0D Cs4PbBr6;
[0039] Figure 1(b) shows the PXRD (X-ray powder diffraction) pattern of the structural transformation process from 3D CsPbBr3 to 0D Cs4PbBr6;
[0040] Figure 1(c) shows the absorbance changes of 3D CsPbBr3 and 0D Cs4PbBr6;
[0041] Figure 2 The microstructure of the perovskite quantum dot negative photoresist in Example 1 of this application is shown, where (a) is the TEM morphology and (b) is the HRTEM morphology.
[0042] Figure 3 This is a comparison between the poorly dispersed photoresist prepared in Comparative Example 1 of this application and the photoresist prepared with perfect compatibility in Example 1. The left bottle contains the photoresist without ligand treatment, and the right bottle contains the photoresist after ligand treatment.
[0043] Figure 4This is a SEM image of the perovskite quantum dot negative photoresist of Example 1 of this application, which can be used to confirm the linewidth;
[0044] Figure 5 This is a demonstration of the application of perovskite quantum dot negative photoresist in the MicroLED production process of Example 1 of this application;
[0045] Figure 6 for Figure 5 A photograph of the product after step 6 of the MicroLED manufacturing process, where perovskite quantum dot photoresist is filled.
[0046] Figure 7 This is a test of the stability of perovskite quantum dots in water in Example 1 and Comparative Example 1. Detailed Implementation
[0047] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0048] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0049] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.
[0050] The core technological improvement in this application is as follows:
[0051] (1) Ligand selection and ratio optimization: Oil-based ammonium salt (OAmX) was used as a ligand, and its molar ratio (Rm) with the initial HPNCs was controlled in the range of 1000 to 29000 to induce the structural transformation of 3D CsPbBr3 material to 0D Cs4PbBr6 material. The schematic diagram of the process is shown in Figure 1(a) to Figure 1(c).
[0052] (2) In-situ core-shell formation mechanism: The 0D phase decomposes into [PbBr4] in a polar solvent system. 2- With Cs + OAm + Through electrostatic interaction with [PbBr4] 2- The combination forms an ordered double shell, with OAm⁺ becoming the outer structure of the perovskite, providing conditions for the perovskite and photoresist to be fully compatible.
[0053] Example 1: Preparation of High-Stability Perovskite Quantum Dot Negative Photoresist
[0054] (1) Preparation of 3D CsPbBr3 template nanocrystals: Using ligand-assisted reprecipitation (LARP), PbBr2 (73.4 mg, 0.2 mmol), CsBr (34.1 mg, 0.16 mmol), oleic acid (0.5 mL), and oleylamine (0.25 mL) were added to 5 mL of DMF / DMSO mixed solution (volume ratio 9:1) and stirred at 60 °C for 1 h until completely dissolved to obtain a precursor solution; 1 mL of the precursor solution was quickly injected into 10 mL of toluene, and after vigorous stirring, the nanocrystals were obtained by a sieving process of "high-speed centrifugation (8000 rpm, 5 min) to remove small-sized crystals - low-speed centrifugation (3000 rpm, 5 min) to remove large-sized crystals" and stored in 12 mL of n-hexane for later use.
[0055] (2) Preparation of OAmX solution: Add 0.5 mmol of oleylamine halide (OAmX, X=Cl, Br, I) to 5 mL of toluene and stir until completely dissolved to obtain OAmX treatment solution.
[0056] (3) 3D→0D structural transformation: Take 5 mL of 3D CsPbBr3 nanocrystal solution (concentration ≈348 nM) filtered through 0.2 μm PTFE, add 5-1000 μL of OAmX treatment solution, and stir at room temperature for 2 h; control the molar ratio (Rm) of OAmX to 3D CsPbBr3. When Rm > 1000, 3D CsPbX3 gradually transforms into 0D Cs4PbX6. The optimal Rm is 5747 (Br system), 57471 (Cl system), and 8621 (I system). In this example, the optimal Rm when X is Br is taken as an example.
[0057] (4) Purification and dispersion in negative photoresist: The mixture obtained in step 3 was mixed with toluene and ethyl acetate at a volume ratio of 1:1:2, centrifuged at 6000 rpm for 2 min, and the precipitate was collected. After vacuum drying, the precipitate was directly dispersed in the PMA system photoresist (this photoresist belongs to the PMA system in g / i line negative photoresist, and the specific components include methyl methacrylate-methacrylic acid (MMA-MAA) copolymer, polar monomers (such as carboxyl groups), and propylene glycol methyl ether acetate (PGMEA) solvent) at a mass ratio of 1:5. The precipitate underwent an OD→in-situ core-shell structure transformation in the photoresist, and OD Cs4PbX6 decomposed to produce [PbBr4]. 2- and with OAm + Self-assembly forms "OAm" + - / 2D / OAm +- Double-shell structure (2D is [PbBr4]) 2- (Anions), ultimately resulting in perovskite quantum dot photoresist that is fully dispersed in PMA negative photoresist.
[0058] Comparative Example 1
[0059] (1) Preparation of 3D CsPbBr3 template nanocrystals: Using ligand-assisted reprecipitation (LARP), PbBr2 (73.4 mg, 0.2 mmol), CsBr (34.1 mg, 0.16 mmol), oleic acid (0.5 mL), and oleylamine (0.25 mL) were added to 5 mL of DMF / DMSO mixed solution (volume ratio 9:1) and stirred at 60 °C for 1 h until completely dissolved to obtain a precursor solution; 1 mL of the precursor solution was quickly injected into 10 mL of toluene, and after vigorous stirring, the nanocrystals were obtained by a sieving process of "high-speed centrifugation (8000 rpm, 5 min) to remove small-sized crystals - low-speed centrifugation (3000 rpm, 5 min) to remove large-sized crystals" and stored in 12 mL of n-hexane for later use.
[0060] (2) 3D CsPbBr3 nanocrystals are added to PMA negative photoresist and stirred and dispersed. The crystal ratio is generally added at a mass ratio of 1:5.
[0061] Since PMA (methacrylate monomer) system photoresist is a polar system, while 3DCsPbBr3 nanocrystals dissolved in n-hexane are a non-polar system with oleic acid ligands, the photoresist prepared by the two is prone to delamination.
[0062] Test Example 1
[0063] Figures 1(a)-1(c) illustrate the structural transformation process induced in this application from 3D CsPbBr3 to 0D Cs4PbBr6. Specifically: Figure 1(a) is a characterization diagram of the structural transformation from 3D CsPbBr3 to 0D Cs4PbBr6; Figure 1(b) is a PXRD (X-ray powder diffraction) pattern, which is direct evidence of the transformation of the material from 3D to 0D crystal using PXRD; and Figure 1(c) shows the absorbance change, which, together with PXRD, confirms the structural transformation of the material.
[0064] Figure 2The TEM / HRTEM morphology of perovskite quantum dot photoresist is shown, where: (a) is the TEM / HRTEM morphology of perovskite photoresist of Comparative Example 1, and (b) is the TEM / HRTEM morphology of perovskite photoresist of Example 1. It can be seen that in (b), the perovskite crystals are dispersed in the photoresist as nanocrystalline phases, while in (a), the dispersion is poor and the perovskite is dispersed as agglomerated macromolecular morphology.
[0065] Figure 3 The images show a physical comparison of the perovskite quantum dot photoresists prepared in Comparative Example 1 (the left bottle marked in the figure) and Example 1 (the right bottle marked in the figure). The perovskite quantum dot photoresist prepared in Comparative Example 1 was not treated with OAmBr ligands, and therefore has poor compatibility with photoresists and is prone to delamination.
[0066] Figure 4 The performance of the perovskite quantum dot photoresist of Example 1 was demonstrated. Specifically, the perovskite quantum dot photoresist was patterned using a stepper lithography machine, and the linewidth of the patterned array was measured using SEM (transmission electron microscopy). The perovskite quantum dot photoresist prepared in Example 1 showed excellent compatibility with the photoresist after ligand post-treatment. The perovskite photoresist prepared in Example 1 has a linewidth ≤2μm when applied to MicroLED lithography arrays, which meets the requirements for use in MicroLEDs.
[0067] Figure 5 A typical process flow diagram for MicroLED fabrication is shown, in which perovskite quantum dot photoresist is involved in step ⑥, a process that requires photolithography to etch the perovskite quantum dot photoresist into an array pattern with a linewidth ≤ 2 micrometers. Figure 6 The image shows the finished product from step ⑥. The finished MicroLED device relies heavily on the excellent performance of the perovskite quantum dot photoresist prepared in this application.
[0068] Figure 7 The results of water stability tests on perovskite quantum dots in Example 1 and Comparative Example 1 are presented, showing that the water stability of Example 1 is significantly improved. The specific steps of the stability test are as follows: 1. Take 5g of each of the two photoresists from Example 1 and Comparative Example 1, and use a semi-automatic spin coater to coat the photoresists into a uniform 4μm thick layer on a 2-inch glass slide; 2. Use a stepper lithography machine to expose and cure the 4μm thick photoresist layer on both glass slides with the same exposure parameters; 3. Immerse the glass slides in pure water at 25°C, and measure the PLQY curves of both as the time in the water increases.
[0069] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A perovskite quantum dot negative photoresist, characterized in that, The preparation method of this perovskite quantum dot negative photoresist includes the following steps: S1. Provide CsPbX3 nanocrystal solution; S2. Add OAmX treatment solution to the CsPbX3 nanocrystal solution, react, wash, separate and dry the reaction product to obtain product powder; S3. Disperse the product powder in a negative photoresist system containing a polar solvent to obtain the perovskite quantum dot negative photoresist. Wherein, OAmX is an oleylamine halide, and X is selected from one of Cl, Br, and I; The reaction conditions include: the reaction is carried out under stirring, the reaction temperature is 20~35°C, and the reaction time is 1~3h; The perovskite quantum dot negative photoresist includes a negative photoresist and a core-shell structured perovskite quantum dot; the shell is generated by in-situ self-assembly of the perovskite quantum dot surface after treatment with OAmX ligand; The molar ratio of OAmX to CsPbX3 nanocrystals is 5000~29000:
1.
2. A method for preparing a perovskite quantum dot negative photoresist, characterized in that, Includes the following steps: S1. Provide CsPbX3 nanocrystal solution; S2. Add OAmX treatment solution to the CsPbX3 nanocrystal solution, react, wash, separate and dry the reaction product to obtain product powder; S3. Disperse the product powder in a negative photoresist system containing a polar solvent to obtain the perovskite quantum dot negative photoresist. The perovskite quantum dot negative photoresist includes a negative photoresist and core-shell structured perovskite quantum dots. OAmX is an oleylamine halide, where X is selected from Cl, Br, and I. The reaction conditions include: the reaction is carried out under stirring, the reaction temperature is 20~35°C, and the reaction time is 1~3h; The shell is generated by in-situ self-assembly of perovskite quantum dots after treatment with OAmX ligands. The molar ratio of OAmX to CsPbX3 nanocrystals is 5000~29000:
1.
3. The preparation method according to claim 2, characterized in that, The CsPbX3 nanocrystal solution was filtered through 0.2 μm PTFE. And / or, the average size of the CsPbX3 nanocrystals is 14~17nm.
4. The preparation method according to claim 2, characterized in that, The negative photoresist is selected from at least one of g / i line negative photoresist, KrF negative photoresist, and ArF negative photoresist.
5. The application of the perovskite quantum dot negative photoresist of claim 1 in the preparation of MicroLEDs and quantum light sources.