An in-situ lead halide perovskite quantum dot diffusion plate and its preparation method and application

Abstract

The present invention belongs to the field of quantum dot preparation technology, specifically relating to an in-situ lead halide perovskite quantum dot diffusion plate, its preparation method, and its application. The preparation method of the present invention innovatively integrates the synthesis of perovskite quantum dots with the preparation of the diffusion plate, omitting the separate synthesis, purification, and granulation processes of the quantum dots, thereby reducing production costs. Furthermore, the use of benzenesulfonic acid monomer compounds and polycarboxylic acids and / or polysulfonic acids as ligands in the preparation of the cationic precursor effectively improves the surface defects of the quantum dots, inhibits Ostwald ripening, and enhances the high-temperature resistance of the quantum dots, thereby facilitating injection molding operations and facilitating mass production.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum dot preparation, and specifically relates to an in-situ lead halide perovskite quantum dot diffusion plate and a preparation method and application thereof. Background Art

[0002] Traditional lead-halide perovskite quantum dots have attracted extensive attention and research due to their superior optical properties, including monodispersity, high fluorescence efficiency, broad absorption, narrow emission, wavelength tunability, high defect tolerance, long carrier lifetime, and a larger absorption cross-section than CdSe@ZnS quantum dots. However, due to the characteristics of lead-halide perovskite ionic crystals, they are extremely sensitive to temperature, humidity, oxygen, and light. Furthermore, defects such as ligand shedding and halogen vacancies caused by the purification process can form defects, ultimately leading to performance degradation. Therefore, perovskites require a relatively harsh, inert environment for optoelectronic applications.

[0003] Currently, quantum dot diffuser technology is being used to encapsulate lead halide perovskite quantum dots in polymers. With the added protection of a water- and oxygen-resistant additive, it can simultaneously achieve light diffusion and color conversion. Its application in traditional LCD displays can significantly enhance the color gamut and brightness. Conventional quantum dot diffuser manufacturing processes, such as those described in Chinese patent CN113534311B, involve synthesizing perovskite quantum dots, mixing them with polymer blanks, and then injection molding them into diffuser plates. However, this method involves synthesizing, purifying, encapsulating, granulating, and injection molding the perovskite quantum dots, resulting in a lengthy and costly process and suboptimal performance.

[0004] To this end, Chinese patent document CN114384615A discloses a method for synthesizing in-situ diffuser plates using a solvent method. This method generates inorganic perovskite quantum dots during the granulation process, avoiding the separate quantum dot synthesis and purification steps, saving time, manpower and material resources, and also avoiding repeated temperature increases and decreases in energy consumption. However, the only drawback is that although this method also utilizes polystyrene (PS), polymethyl methacrylate (PMMA), polycarbonate (PC), etc. to provide an inert environment for the growth and application of perovskite quantum dots, the quantum dots produced by this method are relatively sensitive to temperature and are not resistant to high temperatures. At higher temperatures, they will aggregate and grow, resulting in a sharp decline in luminescence performance. Therefore, rapid cooling is required during the preparation of the diffuser plate, which places high demands on the injection molding process and is not conducive to mass production. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to overcome the poor high temperature resistance of the existing quantum dot diffusion plate and the high requirements for the injection molding process, and then provide an in-situ quantum dot diffusion plate with good high temperature resistance and low requirements for the injection molding process and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] According to an embodiment of the present invention, in a first aspect, the present invention provides a method for preparing an in-situ lead halide perovskite quantum dot diffusion plate, comprising the following steps:

[0008] Mixing a cesium source, a lead source, a first ligand, and a second ligand to obtain a cationic precursor, wherein the first ligand is a monomer compound containing a benzenesulfonic acid group, and the second ligand is a polycarboxylic acid and / or a polysulfonic acid;

[0009] Taking the first halogen source or mixing the second halogen source with an organic amine to obtain an anion precursor;

[0010] The cationic precursor, the anionic precursor, the blank particles, the diffusion particles and the auxiliary materials are mixed and then injection molding is performed to obtain; alternatively, the cationic precursor, the anionic precursor and some blank particles are mixed and then granulated to obtain quantum dot masterbatch, and the quantum dot masterbatch is mixed with the diffusion particles, the remaining blank particles and the auxiliary materials and then injection molding is performed.

[0011] In an embodiment of the present invention, the molar ratio of cesium ions in the cesium source to lead ions in the lead source is 1:0.1-10. If the ratio of cesium ions is too high, Cs4PbBr6 phase will be easily generated, resulting in a decrease in optical performance. Conversely, if the ratio of lead ions is too high, it will also easily lead to a decrease in optical performance.

[0012] In an embodiment of the present invention, the sum of the molar numbers of cesium ions in the cesium source and the lead ions in the lead source: the sum of the molar numbers of benzenesulfonate in the first ligand and the carboxylate and benzenesulfonate in the second ligand = 1:2-30. When the ratio of cations to ligands is less than 1:2, the problem of difficulty in dissolving the precursor will arise. At the same time, the surface of the perovskite does not have sufficient ligand passivation, which will cause surface defects and lead to a decrease in optical performance. If the proportion of ligands is too high, the nucleation and growth of the perovskite will be inhibited, which will bring negative effects.

[0013] In an embodiment of the present invention, in the step of preparing the cationic precursor, the mixture of the cesium source, the lead source, the first ligand and the second ligand is heated to 110-150°C, kept warm for 0-40 minutes, and evacuated to 10-5000 Pa, and then cooled under the protection of an inert atmosphere for use.

[0014] In an embodiment of the present invention, the preparation step of the cationic precursor further includes adding at least one of a potassium source, a manganese source, a strontium source, a zinc source, a nickel source, and octadecene. + 、Mn 2+ 、Sr 2+ 、Zn 2+ 、Ni 2+Stability can be further improved by doping with other materials. As an alternative embodiment, the potassium source can be potassium carbonate or potassium acetate, the manganese source can be manganese acetate or manganese carbonate, the strontium source can be strontium acetate or strontium carbonate, the zinc source can be zinc acetate, and the nickel source can be nickel acetate. Octadecene serves to adjust the precursor concentration and can be added or not, depending on the situation.

[0015] In an embodiment of the present invention, in the step of preparing the anion precursor, the mixture of the second halogen source and the organic amine is heated to 100-150° C., kept warm for 60-150 min, and evacuated to 10-5000 Pa, and then cooled under inert atmosphere for use.

[0016] In an embodiment of the present invention, the molar ratio of the second halogen source to the organic amine is 1:0.3-3.

[0017] In an embodiment of the present invention, the molar ratio of the halogen ions in the first halogen source or the halogen ions in the second halogen source to the cesium ions in the cesium source is 1:0.5-5.

[0018] In an embodiment of the present invention, the first ligand is at least one of dodecylbenzenesulfonic acid, p-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, and 2-aminobenzenesulfonic acid.

[0019] In an embodiment of the present invention, the polycarboxylic acid is at least one of polyacrylic acid, polymaleic acid, poly(styrene)-block poly(acrylic acid), and poly(styrene)-block-poly(acrylic acid).

[0020] In an embodiment of the present invention, the polysulfonic acid is poly(4-styrenesulfonic acid).

[0021] In an embodiment of the present invention, the cesium source is at least one of cesium carbonate, cesium acetate, and cesium bicarbonate.

[0022] In an embodiment of the present invention, the lead source is lead oxide and / or lead acetate.

[0023] In an embodiment of the present invention, by adjusting the ratio of Br / I at the X position of perovskite, the emission wavelength of quantum dots can be regulated and controlled to meet actual needs. As a selectable embodiment, the first halogen source is a quaternary ammonium salt and / or an inorganic halogen salt, and the quaternary ammonium salt is at least one of tetraoctyl ammonium bromide, didodecyl dimethyl ammonium bromide, dioctadecyl dimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, and hexadecyl dimethyl ethyl ammonium bromide, and the inorganic halogen salt is at least one of KBr, NaBr, KI, NaI, and ZnBr. The second halogen source is hydrobromic acid and / or hydroiodic acid.

[0024] In an embodiment of the present invention, the organic amine is at least one of oleylamine, dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

[0025] In an embodiment of the present invention, the blank particles are made of at least one of polystyrene, polymethyl methacrylate, and polycarbonate.

[0026] In an embodiment of the present invention, the mass percentage of the diffusion particles in the diffusion plate is 0.1-10%.

[0027] In an embodiment of the present invention, the diffusion particles are made of at least one of organic silicon, nano-barium sulfate, calcium carbonate, silicon dioxide, titanium dioxide, and zinc oxide.

[0028] In an embodiment of the present invention, the mass percentage of the auxiliary material in the diffusion plate is 0.1-20%.

[0029] In an embodiment of the present invention, the excipient includes at least one of an antioxidant, a light stabilizer, and a heat stabilizer, the antioxidant is at least one of SonoxTM-215, Sonox-1010, and Sonox-168, the light stabilizer is at least one of Chimassorb944, Tinuvin770, and Tinuvin 791, and the heat stabilizer is at least one of antioxidant B215, antioxidant B225, and antioxidant B900.

[0030] According to an embodiment of the present invention, in a second aspect, the present invention further provides an in-situ lead halide perovskite quantum dot diffusion plate prepared by the above preparation method.

[0031] In an embodiment of the present invention, the diffuser plate includes, in terms of mass percentage:

[0032] Perovskite quantum dots 0.02-5%, blank particles 60-99%, diffused particles 0.1-10% and auxiliary materials 0.1-20%; or,

[0033] Perovskite quantum dot masterbatch 1-50%, blank particles 30-90%, diffusion particles 0.1-10% and auxiliary materials 0.1-20%;

[0034] In which, the perovskite quantum dots or the perovskite quantum dot master color particles have a first coating layer and a second coating layer, the first coating layer covers at least a portion of the surface of the perovskite quantum dots or the perovskite quantum dot master color particles, and the first coating layer is the first ligand and the second ligand; the second coating layer covers at least a portion of the surface of the first coating layer, and the second coating layer is at least one of polystyrene, polymethyl methacrylate, and polycarbonate.

[0035] According to an embodiment of the present invention, in a third aspect, the present invention further provides a display comprising the above-mentioned in-situ lead halide perovskite quantum dot diffusion plate.

[0036] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0037] 1. The preparation method of the in-situ lead halide perovskite quantum dot diffusion plate provided by the present invention comprises the following steps: adding a first ligand and a second ligand in the preparation step of the cationic precursor; the first ligand is a benzenesulfonic acid monomer compound; the second ligand is a polycarboxylic acid and / or polysulfonic acid; the presence of these two ligands can effectively improve the surface defects of the quantum dots; the inventors have found that, due to the limitations of the three-dimensional structure of the perovskite quantum dots, only one ligand cannot achieve a good coating effect on the quantum dots; therefore, the present invention utilizes the strong coordination effect of the carboxylate and / or benzenesulfonic acid in the second ligand with the quantum dots to make the second ligand The long polymer chains of the first ligand can cover most of the surface of the quantum dots, and then the strong coordination effect between the benzenesulfonic acid group in the first ligand and the quantum dots is used to make the benzene ring or carbon chain in the first ligand cover the remaining surface of the quantum dots. Therefore, the two ligands cooperate with each other to achieve perfect coverage of the surface of the quantum dots. On the other hand, the two ligands can also inhibit the Ostwald ripening of the quantum dots (that is, the particle size distribution becomes wider, small quantum dots become smaller, and large quantum dots become larger, affecting the optical properties of the quantum dots), improve the high temperature resistance, and allow the diffuser to cool down naturally during the preparation process, which is convenient for the injection molding process operation and conducive to mass production.

[0038] The preparation method of the in-situ lead halide perovskite quantum dot diffusion plate of the present invention can utilize the heat generated by heating and melting during the injection molding / granulation process to disperse the cesium source, lead source, and halogen source in the polymer, and use benzenesulfonic acid monomer compounds and polycarboxylic acids and / or polysulfonic acids as common ligands to in-situ nucleate and grow and form quantum dots with a perovskite@first ligand and second ligand@polymer structure. These double-layer coated quantum dots are evenly dispersed in the diffusion plate, improving the high temperature resistance and water and oxygen barrier capabilities. It can be seen that the preparation method of the present invention innovatively proposes to integrate the synthesis of perovskite quantum dots with the preparation of the diffusion plate, omitting the process of separate synthesis, purification, granulation, etc. of quantum dots, greatly shortening the process and reducing costs. Moreover, compared with the process of granulating first and then forming the diffusion plate, the integrated injection molding process of the present invention also omits the granulation process, that is, omits a heating process, which is more conducive to ensuring the optical properties of the quantum dots.

[0039] 2. The preparation method of the in-situ lead halide perovskite quantum dot diffusion plate provided by the present invention, in the preparation step of the cationic precursor, the mixture of the cesium source, the lead source, the first ligand and the second ligand is heated and vacuumed, thereby promoting the ionization of the benzenesulfonic acid group in the first ligand and the carboxylic acid group and / or the benzenesulfonic acid group in the second ligand, generating corresponding benzenesulfonic acid groups and carboxylic acid groups, which coordinate with the quantum dots to form a good coating effect, further improving the high temperature resistance.

[0040] 3. In the preparation method of the in-situ lead halide perovskite quantum dot diffusion plate provided by the present invention, in the preparation step of the anion precursor, the mixture of the second halogen source and the organic amine is heated and vacuumed to promote the formation of quaternary ammonium salt, provide a good growth environment for perovskite quantum dots, and avoid impurities affecting the growth of quantum dots.

[0041] 4. The in-situ lead halide perovskite quantum dot diffuser provided by the present invention comprises perovskite quantum dots or perovskite quantum dot master color particles comprising a first coating layer and a second coating layer. The first coating layer covers at least a portion of the surface of the perovskite quantum dots or perovskite quantum dot master color particles. The first coating layer comprises a first ligand and a second ligand. The second coating layer covers at least a portion of the surface of the first coating layer. The second coating layer is made of at least one of polystyrene, polymethyl methacrylate, and polycarbonate. The perovskite quantum dots or perovskite quantum dot master color particles in the diffuser of the present invention have a double coating layer structure, which improves their high-temperature resistance and water and oxygen barrier properties. This allows the diffuser of the present invention to achieve both uniform light and color conversion, and is expected to be used in displays. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the specific embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a flow chart of the preparation process of the in-situ quantum dot diffusion plate provided by the present invention.

[0044] Figure 2 This is a photo of the diffuser plate prepared in Example 1 of the present invention under natural light.

[0045] Figure 3 This is a physical picture of the diffuser plate prepared in Example 1 of the present invention under UV light.

[0046] Figure 4 This is the emission spectrum of the diffuser plate prepared in Example 1 of the present invention.

[0047] Figure 5 This is a comparison chart of stability test results of the diffuser plates prepared in Example 1 of the present invention and Comparative Example 1 at 85° C. and 60% RH. DETAILED DESCRIPTION

[0048] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0049] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0050] Example 1: Preparation of green poly (4-styrene sulfonic acid) in-situ lead halide perovskite quantum dot diffusion plate

[0051] (1) Preparation of cationic precursor P1

[0052] Weigh 0.140 g of cesium carbonate, 0.489 g of lead acetate trihydrate, 1.558 g of dodecylbenzenesulfonic acid (90 wt.%), and 4.0433 g of poly(4-styrenesulfonic acid) (Mw ~ 70,000) into a round-bottom flask, slowly heat to 130°C, evacuate to 200 Pa, maintain temperature and pressure for 30 min, then introduce N2, and cool until ready for use.

[0053] (2) Preparation of anion precursor P2

[0054] Measure 500 μL of oleylamine (80-90 wt.%) and 100 μL of 48 wt.% hydrobromic acid in a round-bottom flask, slowly heat to 120°C, evacuate to 200 Pa, maintain temperature and pressure for 120 min, then introduce N2 and cool for later use;

[0055] (3) Preparation of quantum dot diffusion plate

[0056] like Figure 1 As shown, 1.246 g of precursor P1, 125 μL of precursor P2, 200.0 g of PS blank particles, 1.0 g of silicone DF10A0 (diameter 100 nm, Changxing Special Materials (Zhuhai) Co., Ltd.), and 0.533 g of antioxidant SonoxTM-215 were taken in a plastic bag, mixed evenly, and poured into the preheated injection molding machine feed barrel, and the injection molding was started. The extrusion temperature was set to 200 ° C, and the diffusion plate was directly injection molded, as shown. Figure 2-3 shown.

[0057] In terms of mass percentage, the diffusion plate prepared in this embodiment includes: 0.08% perovskite quantum dots, 98.96% blank particles, 0.49% diffusion particles, 0.26% antioxidant and 0.21% free ligands; wherein, the perovskite quantum dots have a first coating layer and a second coating layer, the first coating layer covers at least a portion of the surface of the perovskite quantum dots, the first coating layer is dodecylbenzenesulfonic acid and poly (4-styrenesulfonic acid), the second coating layer covers at least a portion of the surface of the first coating layer, and the second coating layer is polystyrene.

[0058] Figure 4 The emission spectrum of the diffuser plate prepared in this embodiment is also shown. Figure 4 It can be seen that this embodiment can produce an in-situ diffuser with a wavelength of nearly 520nm and a half-height width of nearly 20nm. Figure 5 It can be seen that the double-layer coating of quantum dots can significantly improve the thermal stability of the diffuser plate (85° C., 60% RH).

[0059] Example 2: Preparation of green polyacrylic acid in-situ lead halide perovskite quantum dot diffusion plate

[0060] The only difference between this embodiment and embodiment 1 is that an equal molar amount of polyacrylic acid (Mw ˜110,000) is used to replace the poly(4-styrenesulfonic acid) in embodiment 1.

[0061] Example 3: Preparation of a red in-situ lead halide perovskite quantum dot diffusion plate

[0062] (1) Preparation of cationic precursor P1

[0063] Weigh 0.168 g of cesium carbonate, 0.391 g of lead acetate trihydrate, 1.558 g of dodecylbenzenesulfonic acid (90 wt.%), and 4.043 g of poly(4-styrenesulfonic acid) (Mw ~ 70000), slowly heat to 110 ° C, evacuate to 1000 Pa, maintain temperature and pressure for 30 min, then introduce N2, cool and set aside;

[0064] (2) Preparation of anion precursor P2

[0065] Place 500 μL of 80-90 wt.% oleylamine, 59 μL of 48 wt.% hydrobromic acid, and 41 μL of 45.0-50.0 wt.% hydroiodic acid in a round-bottom flask. Slowly heat to 120°C and evacuate to 1000 Pa. Maintain the temperature and pressure for 120 min, then introduce nitrogen and allow to cool.

[0066] (3) Preparation of quantum dot diffusion plate

[0067] Take 1.232g of precursor P1, 125μL of precursor P2, 200.0g of PS blank particles, 1.0g of silicone DF10A0 (diameter 100nm, Changxing Special Materials (Zhuhai) Co., Ltd.), and 0.533g of antioxidant Sonox-1010 in a plastic bag, mix them evenly, and pour them into the preheated injection molding machine feed barrel, start injection molding, set the extrusion temperature to 210℃, and directly inject it into a diffusion plate.

[0068] Example 4: Preparation of Sr-doped red in-situ lead halide perovskite quantum dot diffusion plate

[0069] The only difference between this embodiment and embodiment 3 is that 0.265 g of strontium acetate is further added in step (1).

[0070] Example 5

[0071] (1) Preparation of cationic precursor P1

[0072] Weigh 1.645 g of cesium acetate, 2.875 g of lead oxide, 4.130 g of p-aminobenzenesulfonic acid, and 5.535 g of polymaleic acid (Mw ~ 7000) in a round-bottom flask, slowly heat to 150°C, evacuate to 3000 Pa, maintain heat and pressure for 30 min, then introduce N2, and cool for later use;

[0073] (2) Preparation of quantum dot masterbatch

[0074] All precursor P1, 18.740g hexadecyltrimethylammonium bromide, and 1000g PMMA blank particles were mixed and put into the extruder feed funnel. The feed temperature was set to 220°C and the discharge temperature was set to 200°C. After mixing and extrusion in the extruder, water cooling, wire drawing, and pelletizing, the perovskite quantum dot masterbatch was obtained.

[0075] (3) Preparation of quantum dot diffusion plate

[0076] Take 20g quantum dot masterbatch, 180g PMMA blank particles, 1.2g titanium dioxide, and 0.8g antioxidant B215 respectively in a plastic bag, mix them evenly, and pour them into the preheated injection molding machine feed barrel, start injection molding, set the extrusion temperature to 180℃, and injection mold into a diffusion plate.

[0077] Measured in percentage by mass, the diffuser plate prepared in this embodiment includes: 9.9% perovskite quantum dot masterbatch, 89.1% blank particles, 0.6% diffusion particles and 0.4% thermal stabilizer; wherein, the perovskite quantum dot masterbatch has a first coating layer and a second coating layer, the first coating layer coats at least a portion of the surface of the perovskite quantum dot masterbatch, the first coating layer is p-aminobenzenesulfonic acid and polymaleic acid, the second coating layer coats at least a portion of the surface of the first coating layer, and the second coating layer is PMMA.

[0078] Comparative Example 1

[0079] This comparative example provides a method for preparing a common in-situ diffusion plate, comprising the following steps:

[0080] (1) Preparation of cationic precursor P1

[0081] Weigh 0.140 g of cesium carbonate, 0.489 g of lead acetate trihydrate, and 3.073 g of oleic acid solution in a round-bottom flask, slowly heat to 130°C, evacuate to 200 Pa, maintain temperature and pressure for 30 min, then introduce N2, and cool for later use;

[0082] (2) Preparation of anion precursor P2

[0083] Measure 500 μL of oleylamine (80-90 wt.%) and 100 μL of 48 wt.% hydrobromic acid in a round-bottom flask, slowly heat to 120°C, evacuate to 200 Pa, maintain temperature and pressure for 120 min, then introduce N2 and cool for later use;

[0084] (3) Preparation of quantum dot diffusion plate

[0085] Take 1.246g of precursor P1, 125μL of precursor P2, 200.0g of PS blank particles, 1.0g of silicone DF10A0 (diameter 100nm, Changxing Special Materials (Zhuhai) Co., Ltd.), and 0.533g of antioxidant SonoxTM-215 in a plastic bag, mix them evenly, and pour them into the preheated injection molding machine feed barrel, start injection molding, set the extrusion temperature to 220℃, and directly inject it into a diffusion plate.

[0086] Comparative Example 2

[0087] The only difference between this comparative example and Example 1 is that 3.947 g of dodecylbenzenesulfonic acid (90 wt.%) is used instead of 1.558 g of dodecylbenzenesulfonic acid and 4.043 g of poly(4-styrenesulfonic acid) in Example 1.

[0088] Comparative Example 3

[0089] The only difference between this comparative example and Example 1 is that 6.675 g of poly(4-styrenesulfonic acid) (Mw˜70,000) is used to replace 1.558 g of dodecylbenzenesulfonic acid and 4.0433 g of poly(4-styrenesulfonic acid) in Example 1.

[0090] Test Example 1

[0091] The quantum efficiency of the diffuser plates prepared in Examples 1-5 and Comparative Examples 1-3 was tested, and the results are shown in Table 1.

[0092] Table 1 Diffuser plate color and quantum efficiency

[0093] Plate color Quantum efficiency Example 1 green 84％ Example 2 green 82％ Example 3 green 78％ Example 4 green 80％ Example 5 green 75％ Comparative Example 1 yellowish 65％ Comparative Example 2 yellowish 60％ Comparative Example 3 yellow 9％

[0094] Test Example 2

[0095] The thermal stability (85°C, humidity 60% RH) of the diffusion plates prepared in Example 1 and Comparative Examples 1-2 was subjected to an anti-aging test. The specific method was as follows: the perovskite quantum dot diffusion plates prepared in Example 1, Comparative Example 1 and Comparative Example 2 were placed on a blue light backplane with a brightness of 300 nits, and the initial brightness of the perovskite quantum dot diffusion plates was tested using a CA-410 brightness meter; then the perovskite quantum dot diffusion plates prepared in Example 1, Comparative Example 1 and Comparative Example 2 were placed in a constant temperature and humidity aging oven at a temperature of 85°C and a humidity of 60%, aged for a certain period of time, and then taken out and the brightness of the perovskite quantum dot diffusion plates after aging was tested using a CA-410 brightness meter, and the percentage of the brightness of the perovskite quantum dot diffusion plates after aging to the initial brightness was recorded. The results are shown as follows: Figure 5 shown.

[0096] from Figure 5 As can be seen, the diffuser plate prepared in Example 1 exhibits excellent thermal stability, maintaining essentially 100% stability within the first 400 hours of testing and maintaining over 80% stability even after 1000 hours. In contrast, the diffuser plate prepared in Comparative Example 1 exhibited stability degradation to approximately 40% within the first 400 hours of testing, and the diffuser plate prepared in Comparative Example 2 also exhibited significant stability degradation within the first 400 hours of testing. This demonstrates that the diffuser plate containing double-coated quantum dots produced in the present invention exhibits superior high-temperature resistance and allows for natural cooling during the preparation process, facilitating the injection molding process and facilitating mass production.

[0097] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing an in-situ lead halide perovskite quantum dot diffusion plate, characterized in that: The steps include: Mixing a cesium source, a lead source, a first ligand, and a second ligand to obtain a cationic precursor, wherein the first ligand is a monomer compound containing a benzenesulfonic acid group, and the second ligand is a polycarboxylic acid and / or a polysulfonic acid; Taking the first halogen source or mixing the second halogen source with an organic amine to obtain an anion precursor; The cationic precursor, the anionic precursor, the blank particles, the diffusion particles and the auxiliary materials are mixed and then injection molding is performed to obtain; or the cationic precursor, the anionic precursor and some blank particles are mixed and then granulated to obtain quantum dot masterbatch, and the quantum dot masterbatch is mixed with the diffusion particles, the remaining blank particles and the auxiliary materials and then injection molding is performed; The molar ratio of cesium ions in the cesium source to lead ions in the lead source is 1:0.1-10; The sum of the molar numbers of cesium ions in the cesium source and lead ions in the lead source: the sum of the molar numbers of benzenesulfonate in the first ligand and the carboxylate and benzenesulfonate in the second ligand=1:2-30.

2. The method for preparing an in-situ lead halide perovskite quantum dot diffusion plate according to claim 1, characterized in that: In the step of preparing the cationic precursor, the mixture of the cesium source, the lead source, the first ligand and the second ligand is heated to 110-150° C., kept warm for 0-40 minutes, and evacuated to 10-5000 Pa, and then cooled under inert atmosphere for use; and / or, The step of preparing the cationic precursor further includes adding at least one of a potassium source, a manganese source, a strontium source, a zinc source, a nickel source, and octadecene.

3. The method for preparing an in-situ lead halide perovskite quantum dot diffusion plate according to claim 1, characterized in that: In the step of preparing the anion precursor, the mixture of the second halogen source and the organic amine is heated to 100-150° C., kept warm for 60-150 minutes, and evacuated to 10-5000 Pa, and then cooled under inert atmosphere for later use; and / or, The molar ratio of the second halogen source to the organic amine is 1:0.3-3; and / or, The molar ratio of the halogen ions in the first halogen source or the halogen ions in the second halogen source to the cesium ions in the cesium source is 1:0.5-5.

4. The method for preparing an in-situ lead halide perovskite quantum dot diffusion plate according to claim 1, characterized in that: Has at least one of the following characteristics: The first ligand is at least one of dodecylbenzenesulfonic acid, p-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, and 2-aminobenzenesulfonic acid; The polycarboxylic acid is at least one of polyacrylic acid, polymaleic acid, poly(styrene)-block poly(acrylic acid), and poly(styrene)-block-poly(acrylic acid); The polysulfonic acid is poly(4-styrenesulfonic acid); The cesium source is at least one of cesium carbonate, cesium acetate, and cesium bicarbonate; The lead source is lead oxide and / or lead acetate; The first halogen source is a quaternary ammonium salt and / or an inorganic halogen salt, the quaternary ammonium salt is at least one of tetraoctylammonium bromide, didodecyldimethylammonium bromide, dioctadecyldimethylammonium bromide, hexadecyltrimethylammonium bromide, and hexadecyldimethylethylammonium bromide, and the inorganic halogen salt is at least one of KBr, NaBr, KI, NaI, and ZnBr2; The second halogen source is hydrobromic acid and / or hydroiodic acid; The organic amine is at least one of oleylamine, dodecylamine, tetradecylamine, hexadecylamine and octadecylamine; The blank particles are made of at least one of polystyrene, polymethyl methacrylate, and polycarbonate.

5. The method for preparing an in-situ lead halide perovskite quantum dot diffusion plate according to claim 1, characterized in that: The mass percentage of the diffusion particles in the diffusion plate is 0.1-10%; and / or, The material of the diffusion particles is at least one of organic silicon, nano-barium sulfate, calcium carbonate, silicon dioxide, titanium dioxide, and zinc oxide.

6. The method for preparing an in-situ lead halide perovskite quantum dot diffusion plate according to claim 1, characterized in that: The mass percentage of the auxiliary material in the diffusion plate is 0.1-20%; and / or, The auxiliary material includes at least one of an antioxidant, a light stabilizer, and a heat stabilizer, the antioxidant is at least one of SonoxTM-215, Sonox-1010, and Sonox-168, the light stabilizer is at least one of Chimassorb944, Tinuvin770, and Tinuvin 791, and the heat stabilizer is at least one of antioxidant B215, antioxidant B225, and antioxidant B900.

7. An in-situ lead halide perovskite quantum dot diffusion plate prepared by the preparation method according to any one of claims 1 to 6.

8. The in-situ lead halide perovskite quantum dot diffusion plate according to claim 7, characterized in that: Measured by mass percentage, the diffuser plate includes: Perovskite quantum dots 0.02-5%, blank particles 60-99%, diffused particles 0.1-10% and auxiliary materials 0.1-20%; or, Perovskite quantum dot masterbatch 1-50%, blank particles 30-90%, diffusion particles 0.1-10% and auxiliary materials 0.1-20%; In which, the perovskite quantum dots or the perovskite quantum dot master color particles have a first coating layer and a second coating layer, the first coating layer covers at least a portion of the surface of the perovskite quantum dots or the perovskite quantum dot master color particles, and the first coating layer is the first ligand and the second ligand; the second coating layer covers at least a portion of the surface of the first coating layer, and the second coating layer is at least one of polystyrene, polymethyl methacrylate, and polycarbonate.

9. A display, characterized in that: Comprising the in-situ lead halide perovskite quantum dot diffusion plate as described in claim 7 or 8.

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