Quantum dot light conversion packaging adhesive film and preparation method and application thereof

Abstract

The invention belongs to the technical field of thin film materials, and particularly relates to a quantum dot light conversion packaging adhesive film and a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing a quantum dot solution with a passivation material solution, and stirring to obtain passivated quantum dots; and (2) dispersing the passivated quantum dots in a solvent A, mixing with a matrix resin solution, stirring, adding an auxiliary agent, reacting, and drying to obtain the quantum dot light conversion packaging adhesive film, the passivation material solution is a tungsten silicic acid solution or an ammonia water solution. The preparation of the quantum dot light conversion packaging adhesive film has the advantages of simple process, easily available raw materials, continuous production and the like, and the photoluminescence quantum yield (PLQY) of the quantum dot / EVA composite film can be close to 90%.

Description

Technical Field

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

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

[0003] Quantum dots are composed of a limited number of atoms whose sizes in three dimensions are all at the nanometer level. They are generally spherical or quasi-spherical nanoparticles with a diameter of 2-20nm. By adjusting the size of quantum dots, ultraviolet light can be converted into different light color emissions. Quantum dots have the characteristics of wide absorption range, adjustable wavelength, high color purity, high fluorescence efficiency and narrow emission half-peak width (FWHM<30nm), and have received widespread attention in the fields of biological imaging, backlight display, white light LED, photovoltaic devices, etc.

[0004] Among them, CsPbX3 perovskite quantum dots (PQDs) have unique advantages because their photoluminescence (PL) can cover the entire visible spectrum (from 400 to 800 nm), their bandgap energy and emission color can be adjusted with the change of halide, and CsPbX3 PQDs have a narrow full width at half maximum (FWHM) of the emission band, high PL quantum yield (PLQY). However, the ionic nature of CsPbX3 nanomaterials and the inevitable structural defects caused by rapid synthesis significantly impair the PLQYs and structural / performance stability, especially in the face of natural environments such as water or other polar solvents, light and heat. Although they have higher defect tolerance compared with semiconductor nanomaterials, various strategies for stabilizing perovskite NCs have been developed, including surface passivation and construction of core-shell structures. The latter is an effective strategy to coat a dense inert shell on CsPbX3 NCs. 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 performance. 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] In view of the shortcomings of the prior art, the present invention provides a quantum dot light conversion packaging film and its preparation method and application. The quantum dot light conversion packaging film of the present invention can convert ultraviolet light below 450nm that cannot be directly absorbed and utilized by solar cells into blue light and green light bands of 480nm-520nm, which are 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: A method for preparing a quantum dot light conversion encapsulation film comprises the following steps: (1) mixing a quantum dot solution and a 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 auxiliary agent, reacting, and drying to obtain the quantum dot light conversion encapsulation film; The passivation material solution is a tungstosilicic acid solution.

[0008] Preferably, the method for preparing the tungstosilicic acid solution comprises the following steps: The tungstosilicic acid powder is mixed with anhydrous ethanol, oleic acid amide and toluene, and stirred to obtain the tungstosilicic acid solution.

[0009] 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 anhydrous ethanol, oleic acid amide and toluene is 1:0.8-1.2:5.5-6.5.

[0010] In another preferred embodiment, the toluene can be replaced by octane.

[0011] 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.

[0012] Further preferably, the quantum dot solution is a blue light quantum dot solution or a green light quantum dot solution; The preparation method of the green light quantum dot solution comprises the following steps: S1. Mixing cesium carbonate, oleic acid and octadecene, vacuum drying, and heating to react to obtain a cesium oleate precursor solution; S2. Mixing lead bromide with oleic acid amide to obtain a PbBr2 suspension; S3. The PbBr2 suspension is mixed with oleamide, oleic acid and octadecene, degassed, heated, added with cesium oleate precursor solution for reaction, cooled, centrifuged and dispersed to obtain a green quantum dot solution.

[0013] 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 oleic acid amide is 1g:30-50mL, the mixing temperature is 110-130°C, and the mixing time is 0.8-1.2h.

[0014] 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 added amount of toluene or octane to the PbBr2 suspension is 2.5-3.5:1.

[0015] Preferably, in step (1), the volume ratio of the quantum dot solution to the passivation material solution is 1:14-16, the stirring speed is 3500-4500 rpm, the stirring time is 25-35 min, and after stirring, the method further comprises the steps of mixing with an equal volume of methyl acetate, centrifuging, dispersing the precipitate and centrifuging again.

[0016] 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.

[0017] 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.

[0018] Further preferably, the content of vinyl acetate in the EVA packaging glue is 30%-35%, and the content of octene in the POE packaging glue is 25%-30%.

[0019] Preferably, in step (2), the stirring temperature 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.

[0020] Preferably, the auxiliary agent in step (2) includes a crosslinking agent or a co-crosslinking agent, the weight percentage of the crosslinking agent or the co-crosslinking agent in the reaction system is 0.01%-5%, the crosslinking agent is a peroxide crosslinking agent, and the crosslinking 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.

[0021] Further preferably, the auxiliary agent also includes an ultraviolet absorber and an antioxidant, the ultraviolet absorber is 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 is 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.

[0022] Preferably, the weight percentage of the ultraviolet absorber and antioxidant in the reaction system is 0.01%-2%.

[0023] The present invention also relates to a quantum dot light-converting packaging adhesive film prepared by the above-mentioned preparation method.

[0024] Preferably, the quantum dot light conversion packaging film has a thickness of 50-90 μm.

[0025] 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.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (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.

[0027] (2) The photoluminescence quantum yield (PLQY) of the quantum dot / EVA composite film of the present invention can reach 89.1%.

[0028] (3) The quantum dot light-converting encapsulating film of the present invention prepares quantum dots with excellent green luminescence performance, and then adopts a one-step method to prepare a quantum dot / EVA composite film, which 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

[0029] Figure 1 is the excitation spectrum of the green CsPbX3 structure quantum dots after passivation in Example 1; Figure 2 is the absorption spectrum of the green CsPbX3 structure quantum dots after passivation in Example 1; Figure 3 This is the excitation spectrum of the green CsPbX3 structure quantum dots in comparative example 1; Figure 4 This is the absorption spectrum of the green CsPbX3 structure quantum dots in comparative example 1; Figure 5 This is the PLQY spectrum of the green CsPbX3 structure quantum dots after passivation in Example 1; Figure 6 This is the PLQY spectrum of green CsPbX3 structure quantum dots in comparative example 1; Figure 7 This is a stability test diagram of the green CsPbX3 structured quantum dots of comparative example 1 and the green CsPbX3 structured quantum dots of embodiment 1. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with specific examples. The following examples are not intended to limit the present invention, but are only intended to illustrate the present invention. The experimental methods used in the following examples are generally conventional, unless otherwise specified, and the materials, reagents, etc. used in the following examples are commercially available, unless otherwise specified.

[0031] OA is the abbreviation of oleic acid, and its chemical formula is C 18 H 34 O2.

[0032] ODE is the abbreviation of 1-octadecene, and its chemical formula is C 18 H36 .

[0033] OAm is the abbreviation of oleic acid amide, and its chemical formula is C 18 H 35 NO.

[0034] EVA particles were purchased from Suzhou Hongdao New Materials Co., Ltd.

[0035] Example 1 A method for preparing a green quantum dot light-converting encapsulation film: (1) Cs2CO3 (0.16 g), OA (0.5 mL) and ODE (8 mL) were placed in a 25 mL three-necked flask and dried under vacuum at 110 °C for 1 h. Then, the solution was heated to 150 °C under N2 until all Cs2CO3 reacted with OA to obtain a clear solution, i.e., cesium oleate precursor solution.

[0036] (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.

[0037] (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 was 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.

[0038] (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 ethanol and 6 mL of toluene) and stir at 4000 rpm for 30 min to obtain a tungstosilicic acid solution.

[0039] (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 the 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 1 The absorption spectrum is shown in Figure 2 shown.

[0040] (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 trimethylolpropane triacrylate by weight of the reaction system was added. After reacting 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.

[0041] The thickness of the green light quantum dot light conversion packaging film prepared by the above preparation method is 50 μm.

[0042] Example 2 A method for preparing a green quantum dot light-converting encapsulation film: (1) Cs2CO3 (0.16 g), OA (0.4 mL) and ODE (9 mL) were placed in a 25 mL three-necked flask and dried under vacuum at 120 °C for 0.8 h. Then, the solution was heated to 140 °C under N2 until all Cs2CO3 reacted with OA to obtain a clear solution, i.e., cesium oleate precursor solution.

[0043] (2) PbBr2 (0.3 g) and OAm (10 mL) were added at 130 °C for 0.8 h to obtain a PbBr2 suspension.

[0044] (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 was 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.

[0045] (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 ethanol and 7 mL of toluene) and stir at 4000 rpm for 30 min to obtain a tungstosilicic acid solution.

[0046] (5) Add 100 μL of tungstosilicic acid solution to 1.5 mL of CsPbBr3 quantum dot solution, stir at 4000 rpm for 30 min, mix the crude solution with an equal volume of methyl acetate, centrifuge at 8000 rpm for 5 min, remove the 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.

[0047] (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 cross-linking agent 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.

[0048] Example 3 A method for preparing a blue light quantum dot encapsulation film: (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.

[0049] (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.

[0050] (3) After stirring for 5 min, the reaction medium was quickly mixed with 1 mL of the precursor solution for 30 s. Finally, the prepared QDs were precipitated by centrifugation at 6000 rpm for 30 min and then dissolved in 2 mL of toluene to obtain a passivated blue light quantum dot solution.

[0051] (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 cross-linking agent was added. After reacting 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.

[0052] Comparative Example 1 The only difference between this comparative example and Example 1 is that the passivation treatment with tungstosilicic acid solution is not performed.

[0053] A method for preparing a green CsPbX3 structure quantum dot light-converting adhesive film, wherein steps (1) to (3) are consistent with those in Example 1, and step (4) is: The CsPbBr3 quantum dot solution was dispersed in hexane solvent, and then mixed with EVA solution (1 g EVA dissolved in 20 mL tetrahydrofuran) at 75°C and 2000 rpm, and 2% peroxide cross-linking agent by weight of the reaction system was added. 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.

[0054] The excitation spectrum of CsPbBr3 quantum dot solution is as follows Figure 3 The absorption spectrum is shown in Figure 4 shown.

[0055] Comparative Example 2 The difference between this comparative example and Example 1 is mainly that the selection of the passivating agent is different; An in-situ GABr passivation treatment strategy was selected to induce the passivation of surface defects and form a stable bromine-rich surface with a three-ligand pattern.

[0056] A mixture of 0.3 g Cs2CO3, 10 mL oleic acid and 20 mL 1-octadecene was placed in a three-necked flask filled with nitrogen. 0.45 g PbBr2 powder and different amounts of guanidine hydrobromide (the molar ratio of CH6BrN3 to PbBr2 was 0.15:1) were placed in a mixture of oleic acid, oleylamine and 1-octadecene (total amount 20 mL) in a three-necked flask filled with nitrogen. The above two mixed solutions were heated and stirred to 120 ° C and kept warm for 2 h. Then the Cs2CO3 mixed solution was heated to 160 ° C and the PbBr2 turbid solution was heated to 170 ° C. The temperature was maintained until Cs2CO3 was completely dissolved. Next, 2 mL of the Cs2CO3 mixed solution was quickly injected into the 20 mL PbBr2 turbid solution. After reacting for 5 s, the mixed solution was transferred to an ice bath and shaken until the solution turned bright green. After centrifuging 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, and 2% of the weight of trimethylolpropane triacrylate was added to 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.

[0057] Comparative Example 3 The difference between this comparative example and Example 1 is only that the synthesis process is changed; (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.

[0058] (2) 0.5 mL of the precursor solution was quickly 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.

[0059] (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 in the subsequent purification process. It 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 culture dish and dried at 60°C to form a film, thereby obtaining a green quantum dot light-converting encapsulation film.

[0060] Effect test Photoluminescence quantum yield (PLQY) test method: The sample is placed in an integrating sphere (equivalent to the sample cavity), and 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 being excited, the fluorescent sample will emit fluorescence, and the fluorescence spectrum is received by the back-end spectrum detection system 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 as follows: Figure 5 and Figure 6 The calculation results are shown in Table 1.

[0061] Aging test method: UV aging test refers to a test method in which a polymer material aging test sample is placed under a UV field for exposure to obtain the aging behavior and law of the polymer material. The present invention uses 12.5 mW·cm -2 , the test was conducted with a xenon lamp light source in the wavelength range of 300nm-400nm. The results are shown in Table 1.

[0062] 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 CsPbBr3QDs was measured using a 405 nm laser diode as the illumination source. Figure 7 shown.

[0063] Table 1 Test results

[0064] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate 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 a quantum dot solution and a 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 auxiliary agent, reacting, and drying to obtain the quantum dot light conversion encapsulation film; 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.

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, oleic acid amide and toluene is 1: 0.8-1.2: 5.5-6.

5.

3. The preparation method according to claim 1, characterized in that: 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.

4. The preparation method according to claim 3, characterized in that: The quantum dot solution is a blue light quantum dot solution or a green light quantum dot solution; The preparation method of the green light quantum dot solution comprises the following steps: S1. Mixing cesium carbonate, oleic acid and octadecene, vacuum drying, and heating to react to obtain a cesium oleate precursor solution; S2. Mixing lead bromide with oleic acid amide to obtain a PbBr2 suspension; S3. The PbBr2 suspension is mixed with oleamide, oleic acid and octadecene, degassed, heated, added with cesium oleate precursor solution for reaction, cooled, centrifuged and dispersed to obtain a green quantum dot solution.

5. The preparation method according to claim 4, 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 oleic acid amide in step S2 is 1g:30-50mL, the mixing temperature is 110-130°C, and the mixing time is 0.8-1.2h.

6. The preparation method according to claim 4, characterized in that: In step S3, the volume ratio of the PbBr2 suspension, oleamide, oleic acid and octadecene 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 added amount of toluene or octane to the PbBr2 suspension is 2.5-3.5:

1.

7. The preparation method according to claim 1, characterized in that: In step (1), the volume ratio of the quantum dot solution to the passivation material solution 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.

8. 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.

9. 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%, and the auxiliary agent includes a crosslinking agent or a co-crosslinking agent, and the crosslinking agent is a peroxide crosslinking agent, and the co-crosslinking 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.

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

11. Application of the quantum dot light-conversion encapsulation film prepared by the preparation method according to any one of claims 1 to 9 in an infrared light-conversion film for photovoltaic cells.

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