A quantum dot light-converting encapsulation film and its preparation method and application

Abstract

The present invention belongs to the field of thin film material technology, and specifically relates to a quantum dot light-conversion encapsulation film, its preparation method, and application. The preparation method comprises the following steps: (1) mixing a quantum dot solution with a passivation material solution, stirring, and obtaining passivated quantum dots; (2) dispersing the passivated quantum dots in solvent A, mixing with a matrix resin solution, stirring, adding an auxiliary agent, reacting, and drying to obtain the quantum dot light-conversion encapsulation film; the passivation material solution is a tungstosilicic acid solution or an ammonia solution. The preparation of the quantum dot light-conversion encapsulation film of the present invention has the advantages of simple process, readily available raw materials, and continuous production. The photoluminescence quantum yield (PLQY) of the quantum dot / EVA composite film can be close to 90%.

Description

Technical Field

[0001] The present invention belongs to the technical field of thin film materials, and in particular relates to a quantum dot light-converting encapsulating film and a preparation method and application thereof. Background Art

[0002] Solar cells convert solar radiation into electrical energy through the photovoltaic effect. Photovoltaic modules are composed of five layers: glass, upper polymer encapsulation film, cell, lower polymer encapsulation film, and backplane or glass. Incident light passes through the upper glass and upper polymer encapsulation film and hits the cell, generating a photovoltaic effect. However, solar cells have a low response to ultraviolet light. Therefore, most of the sunlight cannot be effectively utilized, resulting in low photoelectric conversion efficiency.

[0003] Quantum dots are composed of a finite number of atoms whose dimensions in all three dimensions are nanometers. They are generally spherical or quasi-spherical nanoparticles with diameters ranging from 2 to 20 nm. By manipulating the size of quantum dots, ultraviolet light can be converted into different emission colors. Quantum dots offer a wide absorption range, tunable wavelengths, high color purity, high fluorescence efficiency, and a narrow full width at half maximum (FWHM) of less than 30 nm. They have attracted widespread attention in fields such as bioimaging, backlight displays, white light LEDs, and photovoltaic devices.

[0004] Among them, CsPbX3 perovskite quantum dots (PQDs) offer unique advantages due to their photoluminescence (PL) that covers the entire visible spectrum (from 400 to 800 nm), their bandgap energy and emission color that can be tuned with halide, and their narrow full-width at half-maximum (FWHM) emission band and high PL quantum yield (PLQY). However, the ionic nature of CsPbX3 nanomaterials and the inevitable structural defects arising from their rapid synthesis significantly compromise the PLQY and structural / performance stability, particularly in the presence of water or other polar solvents, light, and heat. Despite their high defect tolerance compared to semiconductor nanomaterials, various strategies have been developed to stabilize perovskite NCs, including surface passivation and core-shell architecture. The latter is an effective strategy for coating CsPbX3 NCs with a dense, inert shell. Currently, materials such as PbSO4, ZnS, and SiO2 have been reported as shell materials. It can improve the long-term stability of equipment in harsh environments.

[0005] However, the band gap and emission wavelength of perovskite NCs with dense inert shells may not be tunable by anion exchange. On the other hand, surface passivation can effectively reduce structural defects and improve luminescence properties. Among them, alkyl ammonium halides, inorganic salts, and ligand molecules that strongly bind to the surface of perovskite NCs are often used for surface passivation of perovskite NCs. Ligand molecules that strongly bind to the surface of perovskite NCs are often used for surface passivation of perovskite NCs, but cannot promote long-term stability, especially in harsh environments. And some surface passivation methods are not always effective for all cesium lead halide perovskite nanocarbons. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention provides a quantum dot light-conversion encapsulation film, its preparation method, and its application. The quantum dot light-conversion encapsulation film can convert ultraviolet light below 450nm, which cannot be directly absorbed and utilized by solar cells, into blue and green light in the 480nm-520nm band, which is easily absorbed by crystalline silicon solar cells and converted into electrical energy.

[0007] In order to achieve the above-mentioned purpose of the present invention, the specific technical solution adopted by the present invention is:

[0008] A method for preparing a quantum dot light-converting encapsulation film comprises the following steps:

[0009] (1) mixing the quantum dot solution with the passivation material solution and stirring to obtain a passivated quantum dot solution;

[0010] (2) dispersing the passivated quantum dot solution in solvent A, mixing with the matrix resin solution, stirring, adding an additive, reacting, and drying to obtain the quantum dot light conversion encapsulation film;

[0011] The passivation material solution is a tungstosilicic acid solution.

[0012] Preferably, the method for preparing the tungstosilicic acid solution comprises the following steps:

[0013] The tungstosilicic acid powder is mixed with anhydrous ethanol, oleic acid amide and toluene, and stirred to obtain the tungstosilicic acid solution.

[0014] Further preferably, the mass volume ratio of the tungstosilicic acid powder to anhydrous ethanol is 1 g:2-3 mL, and the volume ratio of the anhydrous ethanol, oleamide and toluene is 1:0.8-1.2:5.5-6.5.

[0015] In another preferred embodiment, the toluene can be replaced by octane.

[0016] Preferably, the quantum dots are one or two of MAPbX3, CsPbY3, and CdZ, wherein MA is CH3NH3, X is selected from any one of Cl, Br and I, Y is selected from any one of Cl, Br, I, a mixed Cl / Br system and a mixed Br / I system, and Z is selected from any one of S, Se, Zn, a mixed Zn / Se system and a mixed Zn / S system.

[0017] Further preferably, the quantum dot solution is a blue light quantum dot solution or a green light quantum dot solution;

[0018] The preparation method of the green light quantum dot solution comprises the following steps:

[0019] S1. Cesium carbonate, oleic acid and octadecene were mixed, dried under vacuum, and heated to react to obtain a cesium oleate precursor solution;

[0020] S2. Lead bromide is mixed with oleamide to obtain a PbBr2 suspension;

[0021] S3. The PbBr2 suspension is mixed with oleamide, oleic acid and octadecene, degassed, heated, and a cesium oleate precursor solution is added to react, cooled, centrifuged, and dispersed to obtain a green quantum dot solution.

[0022] In another preferred step, the mass volume ratio of cesium carbonate, oleic acid and octadecene in step S1 is 1g:2.5-3.5mL:40-60mL, the vacuum drying temperature is 100-120°C, the drying time is 0.8-1.2h, the heating reaction condition is a nitrogen atmosphere, and the reaction temperature is 140-160°C; in step S2, the mass volume ratio of lead bromide to oleamide is 1g:30-50mL, the mixing temperature is 110-130°C, and the mixing time is 0.8-1.2h.

[0023] In another preferred step, the volume ratio of the PbBr2 suspension, oleamide, oleic acid and octadecene in step S3 is 1:1.5-2.5:1.5-2.5:15-25, the volume ratio of the cesium oleate precursor solution to the PbBr2 suspension is 1:0.8-1.2, the degassing temperature is 100-120°C, the degassing time is 0.8-1.2h, the heating condition is a nitrogen atmosphere, the heating temperature is 150-170°C, the reaction time is 4-6s, the solvent used for dispersion is toluene or octane, and the volume ratio of the amount of toluene or octane added to the PbBr2 suspension is 2.5-3.5:1.

[0024] Preferably, the volume ratio of the quantum dot solution to the passivation material solution in step (1) is 1:14-16, the stirring speed is 3500-4500 rpm, the stirring time is 25-35 min, and after stirring, the steps of mixing with an equal volume of methyl acetate, centrifuging, dispersing the precipitate and centrifuging again are also included.

[0025] Preferably, the solvent A in step (2) is hexane, the volume ratio of the passivated quantum dot solution to the solvent A is 1:2.5-3.5, the matrix resin is polyethylene-polyvinyl acetate copolymer or polypropylene elastomer, the solvent of the matrix resin solution is tetrahydrofuran or cyclohexane, and the mass volume ratio of the matrix resin to tetrahydrofuran or cyclohexane is 1-2g:20-25mL.

[0026] Preferably, the mass ratio of quantum dots to matrix resin is 0.2%-0.8%:1, preferably 0.2%:1, 0.4%:1, 0.6%:1, 0.8%:1.

[0027] Further preferably, the content of vinyl acetate in the EVA encapsulating adhesive is 30%-35%, and the content of octene in the POE encapsulating adhesive is 25%-30%.

[0028] Preferably, the stirring temperature in step (2) is 70-80°C, the stirring speed is 1500-2500 rpm, the reaction time is 2.5-3.5 h, and the drying temperature is 55-65°C.

[0029] Preferably, the auxiliary agent in step (2) includes a cross-linking agent or a co-cross-linking agent, the weight percentage of the cross-linking agent or the co-cross-linking agent in the reaction system is 0.01%-5%, the cross-linking agent is a peroxide cross-linking agent, and the cross-linking auxiliary agent is selected from one or more of triisopropyl isocyanurate, triallyl isocyanurate, triallyl isocyanurate, di(trimethylolpropane) tetraacrylate, 1,3,5-tri-2-propenyl-1,3,5-triazine, 2,4,6(1H,3H,5H)-trione, triallyl isocyanate, triallyl isocyanurate and triallyl isocyanurate.

[0030] Further preferably, the auxiliary agent further comprises an ultraviolet absorber and an antioxidant, the ultraviolet absorber being selected from one or more of [2-hydroxy-4 (octyloxy) phenyl] phenyl ketone, 2-hydroxy-4-n-octyloxy benzophenone, 2-hydroxy-4-n-octyloxy benzophenone and 3,5-di-tert-butyl-4-hydroxybenzoic acid-2,4-di-tert-butylphenyl ester, and the antioxidant being selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris(nonylphenyl) phosphite and bis(3,5-tert-butyl-4-hydroxyphenyl) sulfide.

[0031] Furthermore, preferably, the weight percentage of the ultraviolet absorber and antioxidant in the reaction system is 0.01%-2%.

[0032] The present invention also relates to a quantum dot light-converting packaging film prepared by the above-mentioned preparation method.

[0033] Preferably, the thickness of the quantum dot light conversion packaging film is 50-90 μm.

[0034] The present invention also relates to the application of the quantum dot light-converting encapsulating adhesive film prepared by the above-mentioned preparation method in the infrared light-converting film of photovoltaic cells.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The preparation of the quantum dot light conversion encapsulation film of the present invention has the advantages of simple process, easy availability of raw materials, and continuous production.

[0037] (2) The photoluminescence quantum yield (PLQY) of the quantum dot / EVA composite film of the present invention can reach 89.1%.

[0038] (3) The quantum dot light-conversion encapsulation film of the present invention produces quantum dots with excellent green luminescence performance, and then a quantum dot / EVA composite film is prepared by a one-step method. The composite film can convert ultraviolet light (which cannot be directly absorbed by solar cells) into visible light, thereby improving the light absorption capacity of solar cells and further improving their photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the excitation spectrum of the green CsPbX3 structure quantum dots after passivation in Example 1;

[0040] Figure 2 This is the absorption spectrum of the green CsPbX3 structure quantum dots after passivation in Example 1;

[0041] Figure 3 This is the excitation spectrum of the green CsPbX3 structure quantum dots in comparative example 1;

[0042] Figure 4 This is the absorption spectrum of the green CsPbX3 structure quantum dots in comparative example 1;

[0043] Figure 5 This is the PLQY spectrum of the green CsPbX3 structure quantum dots after passivation in Example 1;

[0044] Figure 6 This is the PLQY spectrum of the green CsPbX3 structure quantum dots in comparative example 1;

[0045] Figure 7This is a stability test diagram of the green CsPbX3 structure quantum dots of comparative example 1 and the green CsPbX3 structure quantum dots of embodiment 1. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to specific examples. The following examples are not intended to limit the present invention but are merely intended to illustrate the present invention. The experimental methods used in the following examples are generally based on conventional conditions unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified.

[0047] OA is the abbreviation of oleic acid, and its chemical formula is C 18 H 34 O2.

[0048] ODE is the abbreviation of 1-octadecene, and its chemical formula is C 18 H 36 .

[0049] OAm is the abbreviation of oleic acid amide (English name Oleic acid amide), and its chemical formula is C 18 H 35 NO.

[0050] EVA particles were purchased from Suzhou Hongdao New Materials Co., Ltd.

[0051] Example 1

[0052] A method for preparing a green quantum dot light-converting encapsulation film:

[0053] (1) Cs2CO3 (0.16 g), OA (0.5 mL), and ODE (8 mL) were placed in a 25 mL three-necked flask and dried in vacuum at 110 °C for 1 h. The solution was then heated to 150 °C under N2 until all Cs2CO3 reacted with OA to obtain a clear solution, i.e., the cesium oleate precursor solution.

[0054] (2) PbBr2 (0.414 g) and OAm (20 mL) were heated at 120°C and stirred at 155 rpm for 1 h to obtain a PbBr2 suspension.

[0055] (3) PbBr2 (1 mL) suspension, OAm (2 mL), OA (2 mL), and ODE (20 mL) were placed in a 50 mL three-necked flask, degassed at 110 °C for 1 h, and heated to 160 °C under N2. After the PbBr2 powder dissolved, 1 mL of the prepared hot cesium oleate precursor solution was quickly injected into the PbBr2 solution. After 5 seconds, the crude solution was immediately cooled in an ice water bath. The crude solution was centrifuged at 10,000 rpm for 10 min to remove residual reactants. The precipitate was redispersed in 10 mL of toluene and centrifuged at 4,000 rpm for 6 min to obtain the CsPbBr3 quantum dot solution.

[0056] (4) Dissolve 0.4 g of tungstosilicic acid powder in 1 mL of anhydrous ethanol, then slowly drop the solution into the mixture (1 mL of 0.1 Ammonium hydroxide and 6 mL of toluene) and stir at 4000 rpm for 30 min to obtain a tungstosilicic acid solution.

[0057] (5) Add 100 μL of tungstosilicic acid solution to 1.5 mL of CsPbBr3 quantum dot solution and stir at 4000 rpm for 30 min. Mix the crude solution with an equal volume of methyl acetate and centrifuge at 8000 rpm for 5 min to remove excess tungstosilicic acid solution. Redisperse the precipitate in 1.5 mL of toluene and centrifuge at 3000 rpm for 3 minutes to obtain a passivated quantum dot solution. Its excitation spectrum is shown in Figure 2. Figure 1 As shown, the absorption spectrum is Figure 2 shown.

[0058] (6) The quantum dot solution was dispersed in 3 mL of hexane solvent, and then mixed with EVA solution (1 g of EVA particles dissolved in 20 mL of tetrahydrofuran) at 75 °C and 2000 rpm, and 2% of the weight of the reaction system of trimethylolpropane triacrylate was added. After the reaction for 3 h, the resulting solution was poured into a culture dish and dried at 60 °C to form a film, thereby obtaining a green quantum dot light-converting encapsulation film.

[0059] The thickness of the green quantum dot light conversion packaging film prepared by the above preparation method is 50 μm.

[0060] Example 2

[0061] A method for preparing a green quantum dot light-converting encapsulation film:

[0062] (1) Cs2CO3 (0.16 g), OA (0.4 mL), and ODE (9 mL) were placed in a 25 mL three-necked flask and dried in vacuum at 120 °C for 0.8 h. The solution was then heated to 140 °C under N2 until all Cs2CO3 reacted with OA to obtain a clear solution, i.e., the cesium oleate precursor solution.

[0063] (2) PbBr2 (0.3 g) and OAm (10 mL) were added at 130 °C for 0.8 h to obtain a PbBr2 suspension.

[0064] (3) PbBr2 (1 mL) suspension, OAm (1.5 mL), OA (1.5 mL), and ODE (25 mL) were placed in a 50 mL three-necked flask, degassed at 120 °C for 0.8 h, and heated to 170 °C under N2. After the PbBr2 powder dissolved, 1 mL of the prepared hot cesium oleate precursor solution was quickly injected into the PbBr2 solution. After 5 seconds, the crude solution was immediately cooled in an ice-water bath. The crude solution was centrifuged at 10,000 rpm for 10 min to remove residual reactants. The precipitate was redispersed in 10 mL of toluene and centrifuged at 4,000 rpm for 6 min to obtain a CsPbBr3 quantum dot solution.

[0065] (4) Dissolve 0.4 g of tungstosilicic acid powder in 1.2 mL of anhydrous ethanol, then slowly drop the solution into the mixture (1 mL of 0.1 Ammonium hydroxide and 7 mL of toluene) and stir at 4000 rpm for 30 min to obtain a tungstosilicic acid solution.

[0066] (5) Add 100 μL of tungstosilicic acid solution to 1.5 mL of CsPbBr3 quantum dot solution and stir at 4000 rpm for 30 min. Mix the crude solution with an equal volume of methyl acetate and centrifuge at 8000 rpm for 5 min to remove excess tungstosilicic acid solution. Redisperse the precipitate in 1.5 mL of toluene and centrifuge at 3000 rpm for 3 minutes to obtain a passivated quantum dot solution.

[0067] (6) The quantum dot solution was dispersed in 5 mL of hexane solvent, and then mixed with EVA solution (2 g of EVA dissolved in 25 mL of tetrahydrofuran) at 70 °C and 2500 rpm, and 3% of the weight of the reaction system peroxide crosslinker was added. After reacting for 2.5 h, the resulting solution was poured into a culture dish and dried at 65 °C to form a film, thereby obtaining a green quantum dot light-converting encapsulation film.

[0068] Example 3

[0069] A method for preparing a blue light quantum dot encapsulation film:

[0070] (1) Lead bromide (PbBr2, 0.2 mmol) and cesium bromide (CsBr, 0.2 mmol) were dissolved in 5 mL of DMF at room temperature. A total of 0.25 mL of oleylamine was added to the above mixture to obtain a precursor solution.

[0071] (2) Subsequently, 1 mL of oleic acid was added to 10 mL of toluene, and then 10 μL of an aqueous ammonia solution (20 wt%) was added to the mixture.

[0072] (3) After stirring for 5 minutes, the reaction medium was quickly mixed with 1 mL of the precursor solution for 30 seconds. Finally, the prepared QDs were precipitated by centrifugation at 6000 rpm for 30 minutes and then dissolved in 2 mL of toluene to obtain a passivated blue light quantum dot solution.

[0073] (4) The quantum dot solution was dispersed in 3 mL of hexane solvent, and then mixed with EVA solution (1 g of EVA dissolved in 20 mL of tetrahydrofuran) at 75 °C and 2000 rpm, and 2% of the weight of the reaction system peroxide crosslinker was added. After the reaction for 3 h, the resulting solution was poured into a culture dish and dried at 60 °C to form a film, thereby obtaining a blue light quantum dot light conversion encapsulation film.

[0074] Comparative Example 1

[0075] The only difference between this comparative example and Example 1 is that the passivation treatment with tungstosilicic acid solution is not performed.

[0076] A method for preparing a green CsPbX3 structured quantum dot light-converting adhesive film, wherein steps (1) to (3) are consistent with those in Example 1, and step (4) is:

[0077] The CsPbBr3 quantum dot solution was dispersed in hexane solvent, then mixed with EVA solution (1g EVA dissolved in 20mL tetrahydrofuran) at 75°C and 2000rpm, and a peroxide crosslinker was added at 2% by weight of the reaction system. After reacting for 3 hours, the resulting solution was poured into a Petri dish and dried at 60°C to form a film, thereby obtaining a green quantum dot light-converting encapsulation film.

[0078] The excitation spectrum of CsPbBr3 quantum dot solution is as follows Figure 3 As shown, the absorption spectrum is Figure 4 shown.

[0079] Comparative Example 2

[0080] The main difference between this comparative example and Example 1 is that the passivating agent is selected differently;

[0081] An in-situ GABr passivation treatment strategy was selected to induce surface defect passivation and form a stable bromine-rich surface with a three-ligand pattern.

[0082] A mixture of 0.3 g of Cs2CO3, 10 mL of oleic acid, and 20 mL of 1-octadecene was placed in a three-necked flask filled with nitrogen. 0.45 g of PbBr2 powder and varying amounts of guanidine hydrobromide (CH6BrN3:PbBr2 molar ratio 0.15:1) were added to a mixture of oleic acid, oleylamine, and 1-octadecene (total 20 mL) in a nitrogen-filled three-necked flask. The two mixtures were heated and stirred to 120°C and maintained at this temperature for 2 h. The Cs2CO3 mixture was then heated to 160°C, and the turbid PbBr2 solution was heated to 170°C. The temperatures were maintained until the Cs2CO3 was completely dissolved. Next, 2 mL of the Cs2CO3 mixture was rapidly injected into the 20 mL of the turbid PbBr2 solution. After 5 seconds of reaction, the mixture was transferred to an ice bath and shaken until it turned bright green. After centrifugation at 1000 rpm for 5 minutes with excess ethyl acetate (volume ratio of 2:1), the precipitate was dispersed in 5 mL of cyclohexane and then mixed with EVA solution (1 g of EVA particles dissolved in 20 mL of tetrahydrofuran) at 75°C and 2000 rpm. Trimethylolpropane triacrylate was added at 2% by weight of the reaction system. After reacting for 3 hours, the resulting solution was poured into a culture dish and dried at 60°C to form a film, thereby obtaining a green quantum dot light-converting encapsulation film.

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 1 is only the change in the synthesis process;

[0085] (1) PbBr2 (0.4 mmol), CsBr (0.4 mmol), and 2.4 mL of anhydrous OAm were added to 10 mL of anhydrous DMF. The mixture was stirred at room temperature until completely dissolved to obtain a precursor solution.

[0086] (2) 0.5 mL of the precursor solution was rapidly injected into 10 mL of a mixed solution (containing 5 mL of hexane and 5 mL of toluene). The colorless solution immediately turned green. After 10 seconds, the reaction was terminated by centrifugation to obtain a crude colloidal solution.

[0087] (3) The crude colloidal solution was centrifuged at 11,000 rpm for 15 minutes at 10°C. The precipitate was then collected and dispersed in hexane. This process was repeated twice during the subsequent purification process. The solution was then mixed with an EVA solution (2 g EVA dissolved in 35 mL tetrahydrofuran) at 75°C and 2,000 rpm, and a peroxide crosslinker was added at 2% by weight of the reaction system. After reacting for 3 hours, the resulting solution was poured into a Petri dish and dried at 60°C to form a film, thereby obtaining a green quantum dot light-converting encapsulation film.

[0088] Effect test

[0089] Photoluminescence quantum yield (PLQY) test method:

[0090] The sample is placed in an integrating sphere (equivalent to the sample cavity). The continuous spectrum emitted by the xenon lamp is split by a monochromator and then introduced to the sample in the integrating sphere through an optical fiber. After the fluorescent sample is excited, it will emit fluorescence. The fluorescence spectrum is received by the spectrum detection system at the back end through the optical fiber. The detector can achieve high-sensitivity multi-wavelength real-time measurement. The internal quantum yield is calculated by the ratio of the number of emitted photons (green area) and the number of absorbed photons (blue area). The PLQY of Example 1 and Comparative Example 1 are shown as follows: Figure 5 and Figure 6 The calculation results are shown in Table 1.

[0091] Aging test method: UV aging test is to expose the polymer material aging test sample to UV light field to obtain the aging behavior and regularity of the polymer material. -2 The test was conducted using a xenon lamp light source with a wavelength range of 300nm-400nm. The results are shown in Table 1.

[0092] Stability test method: using a power intensity of 12.5 mW·cm -2 The normalized time-dependent current density of the photodetectors based on pristine CsPbBr3 and passivated CsPbBr3 QDs was measured using a 405 nm laser diode as the illumination source. Figure 7 shown.

[0093] Table 1 Test results

[0094]

[0095] The above detailed description is a specific description of one feasible embodiment of the present invention. This embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not depart from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A method for preparing a quantum dot light conversion encapsulation film, characterized in that: The following steps are involved: (1) mixing the quantum dot solution with the passivation material solution and stirring to obtain a passivated quantum dot solution; (2) dispersing the passivated quantum dot solution in solvent A, mixing with the matrix resin solution, stirring, adding an additive, reacting, and drying to obtain the quantum dot light conversion encapsulation film; The quantum dot solution is a green light quantum dot solution; The passivation material solution is a tungstosilicic acid solution; The preparation method of the tungstosilicic acid solution comprises the following steps: mixing tungstosilicic acid powder with anhydrous ethanol, oleic acid amide and toluene, and stirring to obtain the tungstosilicic acid solution; The quantum dots are CsPbY3, and Y is selected from any one of Cl, Br, I, a mixed Cl / Br system, and a mixed Br / I system.

2. The preparation method according to claim 1, characterized in that The mass volume ratio of the tungstosilicic acid powder to anhydrous ethanol is 1 g:2-3 mL, and the volume ratio of the anhydrous ethanol, oleamide and toluene is 1:0.8-1.2:5.5-6.

5.

3. The preparation method according to claim 1, characterized in that The preparation method of the green light quantum dot solution comprises the following steps: S1. Cesium carbonate, oleic acid and octadecene were mixed, dried under vacuum, and heated to react to obtain a cesium oleate precursor solution; S2. Lead bromide is mixed with oleamide to obtain a PbBr2 suspension; S3. The PbBr2 suspension is mixed with oleamide, oleic acid and octadecene, degassed, heated, and a cesium oleate precursor solution is added to react, cooled, centrifuged, and dispersed to obtain a green quantum dot solution.

4. The preparation method according to claim 3, characterized in that The mass volume ratio of cesium carbonate, oleic acid and octadecene in step S1 is 1g:2.5-3.5mL:40-60mL, the vacuum drying temperature is 100-120°C, the drying time is 0.8-1.2h, the heating reaction condition is a nitrogen atmosphere, and the reaction temperature is 140-160°C; the mass volume ratio of lead bromide and oleamide in step S2 is 1g:30-50mL, the mixing temperature is 110-130°C, and the mixing time is 0.8-1.2h.

5. The preparation method according to claim 3, characterized in that The volume ratio of the PbBr2 suspension, oleamide, oleic acid and octadecene in step S3 is 1:1.5-2.5:1.5-2.5:15-25, the volume ratio of the cesium oleate precursor solution to the PbBr2 suspension is 1:0.8-1.2, the degassing temperature is 100-120°C, the degassing time is 0.8-1.2h, the heating condition is a nitrogen atmosphere, the heating temperature is 150-170°C, the reaction time is 4-6s, the solvent used for dispersion is toluene or octane, and the volume ratio of the amount of toluene or octane added to the PbBr2 suspension is 2.5-3.5:

1.

6. The preparation method according to claim 1, characterized in that The volume ratio of the quantum dot solution to the passivation material solution in step (1) is 1:14-16, the stirring speed is 3500-4500 rpm, and the stirring time is 25-35 minutes. After stirring, the process also includes mixing with an equal volume of methyl acetate, centrifuging, dispersing the precipitate, and centrifuging again.

7. The preparation method according to claim 1, characterized in that In step (2), the solvent A is hexane, the volume ratio of the passivated quantum dot solution to the solvent A is 1:2.5-3.5, the matrix resin is polyethylene-polyvinyl acetate copolymer or polypropylene elastomer, the solvent of the matrix resin solution is tetrahydrofuran or cyclohexane, the mass volume ratio of the matrix resin to tetrahydrofuran or cyclohexane is 1-2g:20-25mL, the stirring temperature is 70-80°C, the stirring speed is 1500-2500rpm, the reaction time is 2.5-3.5h, and the drying temperature is 55-65°C.

8. The preparation method according to claim 1, characterized in that The weight percentage of the auxiliary agent in the reaction system in step (2) is 0.01%-5%.

9. A quantum dot light conversion encapsulation film prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The thickness of the quantum dot light-converting packaging film is 50-90 μm.

10. Use of the quantum dot light-conversion encapsulation film prepared by the preparation method according to any one of claims 1 to 8 in an infrared light-conversion film for photovoltaic cells.

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