High-oxidation-resistance and migration-resistance type light conversion micelles, packaging adhesive film and photovoltaic module

Abstract

The invention belongs to the technical field of photovoltaic materials, and particularly relates to a high-oxidation-resistance anti-migration type light conversion micellar, a packaging adhesive film and a photovoltaic module, the high-oxidation-resistance anti-migration type light conversion micellar comprises a functional inner core and a shell layer coating the surface of the functional inner core; the functional core comprises a chromophore with down-conversion capability; the chromophore is prepared by hydrolyzing a benzotriazole monomer containing a silicon atom or a carbon-carbon double bond, a hydroxyl group, a carboxyl group, a carbonyl group, an ester group and an amido group, and condensing into a cyclic macromolecule through a silicon-oxygen bond, so as to obtain a benzotriazole cyclized compound; the shell layer is a high-oxygen-barrier protective layer; the light conversion micelles are mutually bonded through silicon-oxygen bonds to form oligomer core micelles with ring-shaped or net-shaped structures; according to the invention, the light conversion micelles with core-shell structures are arranged, the light conversion micelles with large molecular weight can keep fixed positions and have no migration or gravity settlement in the stages from storage and transportation to melt flow before lamination, and the shell layer formed by crosslinking has low oxygen permeability and can block diffusion of oxygen and peroxide free radicals in the adhesive film to the functional core at the same time.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic materials technology, specifically relating to a highly antioxidant and migration-resistant light-converting microparticle, an encapsulating film, and a photovoltaic module. Background Technology

[0002] Light-converting films convert ultraviolet or part of the visible light into visible-near-infrared light, preventing ultraviolet rays from damaging the encapsulation film and silicon cells. At the same time, they enable the spectral response of silicon cells to better match the solar spectrum, thereby improving module power. This has become one of the important technical paths to increase battery power generation and reduce the cost per kilowatt-hour.

[0003] Small molecule organic fluorescent agents or rare earth complexes are used as light-converting agents. These low-molecular-weight active substances have limited solubility in organic matrices, are prone to migration, precipitation, aggregation, and quenching, and have insufficient oxygen barrier capacity, making them difficult to resist oxidative aging. Once the light-converting agent fails, the encapsulating film will undergo photo-oxidation, hydrolysis, and free radical cleavage under the synergistic effects of ultraviolet light, humidity, and oxygen, leading to yellowing. At the same time, unconverted ultraviolet light penetrates the encapsulating film, directly damaging the solar cells, thereby reducing the output power and lifespan of the module.

[0004] Anti-migration light-converting agent technology often involves introducing unsaturated bonds or heteroatoms into the molecule, which then covalently crosslink with the matrix resin during lamination, thereby "anchoring" the light-converting component. However, this chemical bonding only takes effect during the lamination stage. During the previous film storage and transportation, the light-converting agent may still migrate due to poor compatibility, and the potential risks of performance degradation and contamination have not been eliminated.

[0005] Therefore, overcoming the risk of migration of the light-converting agent in the light-converting film before lamination is a technical problem that urgently needs to be solved in this field.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0007] This disclosure provides at least one highly antioxidant and migration-resistant light-converting microcell, an encapsulating film, and a photovoltaic module.

[0008] In a first aspect, embodiments of this disclosure provide a light-converting micro-group, comprising: a functional core and a shell covering its surface; the functional core includes a chromophore containing downconversion capability; the chromophore includes a benzotriazole monomer containing silicon atoms or carbon-carbon double bonds, hydroxyl groups, carboxyl groups, carbonyl groups, ester groups, or amide groups, which is hydrolyzed and condensed into a cyclic macromolecule through silicon-oxygen bonds to obtain a benzotriazole cyclization; the shell is a high oxygen barrier protective layer; the light-converting micro-groups are bonded to each other by silicon-oxygen bonds to form oligomer core micro-groups with cyclic or network structures.

[0009] In one optional embodiment, the molecular formula of the benzotriazole monomer containing silicon atoms or carbon-carbon double bonds, hydroxyl groups, carboxyl groups, carbonyl groups, ester groups, or amide groups is: ; Where R is a siloxane or other functional group, and n is in the range of 2 < n < 15.

[0010] In one optional embodiment, the molecular formula of the benzotriazole cyclide includes: , , , , , , , Any one or more combinations thereof.

[0011] In one alternative embodiment, the high oxygen barrier layer comprises at least one of ethylene-vinyl alcohol copolymer or polyvinyl alcohol copolymer.

[0012] In one optional embodiment, the particle size of the light-converting micro-clusters is 100–160 nm; the particle size of the functional core is 80–110 nm; and the thickness of the shell layer is 20–50 nm.

[0013] Secondly, this disclosure also provides a method for preparing the light-converting micro-clusters as described above, comprising the following steps: S1, dispersing benzotriazole monomers containing silicon atoms or other functional groups into nanoscale microemulsion droplets, and performing siloxane hydrolysis-condensation to form a functional core; S2, adding a shell material and a crosslinking agent / initiator to the microemulsion containing the functional core, initiating crosslinking of the shell material molecules, forming a dense coating on the surface of the functional core, and obtaining the light-converting micro-clusters.

[0014] Thirdly, embodiments of this disclosure also provide an encapsulating film comprising at least one light-converting microparticle as described above and an organic polymer material, comprising the following components by mass parts: 100 parts of organic polymer material, 0.01 to 2 parts of light-converting microparticle, 0.01 to 1.1 parts of light stabilizer, 0.1 to 2 parts of crosslinking agent, 0.1 to 2 parts of co-crosslinking agent, and 0.1 to 1.2 parts of silane coupling agent.

[0015] In one optional embodiment, the thickness of the encapsulating film is 10 to 1000 μm, and the mass percentage of the highly antioxidant and anti-migration optically active micro-groups is 0.01 to 2 wt%.

[0016] In one optional embodiment, the organic polymer material includes any one or more combinations of thermoplastic polyolefins, polyvinyl butyral, polyolefin elastomers, polyurethanes, thermoplastic polyurethanes, polyacrylates, ethylene vinyl acetate copolymers, organosilicon, and EEA ionomers.

[0017] Fourthly, this disclosure also provides a photovoltaic module, which, from top to bottom, includes glass, a first encapsulating film, a solar cell, a second encapsulating film, and a backsheet or glass; wherein the first encapsulating film is the encapsulating film as described above.

[0018] The beneficial effects of this invention are that the high-antioxidant and anti-migration light-converting micro-cells, encapsulating films, and photovoltaic modules, by setting core-shell structured light-converting micro-cells, can efficiently convert 280-380nm ultraviolet light into 400-600nm visible light. At the same time, compared with small molecule light-converting reagents, large molecular weight light-converting micro-cells can maintain a fixed position during the melt flow stage before storage and transportation to lamination, without migration or gravity sedimentation. Moreover, the cross-linked shell has low oxygen permeability, which can simultaneously block the diffusion of oxygen and peroxide free radicals in the film to the functional core. After lamination, the micro-cell core, micro-cell cross-linked shell, and encapsulating film matrix can be covalently bonded to form a continuous three-dimensional network structure, so that the light-converting micro-cells are anchored to the network nodes, achieving permanent fixation and barrier protection.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the highly antioxidant and anti-migration optically active micro-cells provided in the embodiments of this disclosure; Figure 2 Photographs of the EVOH shell microparticle film after lamination at 148°C provided in this embodiment of the present disclosure, before (left) and after (right) UV aging, under 365nm wavelength light irradiation; Figure 3 Photographs of the PVA shell microparticle film after lamination at 148°C provided in this embodiment of the present disclosure, before (left) and after (right) UV aging, under 365nm wavelength light irradiation. Figure 4 Photographs of a conventional light-converting film after lamination at 148°C provided in this embodiment of the present disclosure, before (left) and after (right) UV aging, under 365nm wavelength light irradiation; Figure 5 Photographs of the anti-migration light-converting film provided in this embodiment of the present disclosure after lamination at 148°C, before (left) and after (right) UV aging, under 365nm wavelength light irradiation; Figure 6 Photographs of a conventional photoconverting film before (left) and after (right) baking at 60 °C for 7 days, provided in this embodiment of the present disclosure, under 365 nm wavelength light irradiation; Figure 7 Photographs of a conventional photoconverting film before (left) and after (right) baking at 60 °C for 7 days, provided in this embodiment of the present disclosure, under 365 nm wavelength light irradiation; Figure 8 Photographs of a conventional photoconverting film before (left) and after (right) baking at 60 °C for 7 days, provided in this embodiment of the present disclosure, under 365 nm wavelength light irradiation; Figure 9 The images show the anti-migration light-converting film before (left) and after (right) baking at 60 °C for 7 days, as provided in the embodiments of this disclosure, under 365 nm wavelength light irradiation.

[0023] In the picture: 1. Functional kernel; 2. Shell. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0026] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0027] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] This disclosure provides a light-converting micro-group, comprising: a functional core and a shell covering its surface; the functional core includes chromophores with downconversion capability; the chromophores include benzotriazole monomers containing silicon atoms or carbon-carbon double bonds, hydroxyl groups, carboxyl groups, carbonyl groups, ester groups, or amide groups, which are hydrolyzed and condensed into cyclic macromolecules through silicon-oxygen bonds to obtain benzotriazole cyclides; the shell is a high oxygen barrier protective layer; the light-converting micro-groups are bonded to each other by silicon-oxygen bonds to form oligomer core micro-groups with cyclic or network structures.

[0031] Specifically, this invention constructs antioxidant light-converting microparticles at the nanoscale through the hydrolysis-condensation reaction of benzotriazole monomers containing siloxanes or other functional groups: siloxane bonds break and recombine in an aqueous environment to form a cyclic macromolecular spherical framework; based on this, an initiator / crosslinking agent induces EVOH or PVA to form a dense coating layer on the surface of the microparticles, constructing a core-shell structure, wherein the core layer provides light conversion function, and the shell layer imparts antioxidant and interfacial compatibility; by regulating the synergistic kinetic parameters of hydrolysis-condensation-crosslinking, the size and interfacial bonding strength of the core-shell structure are precisely controlled, so that it exhibits a narrow distribution within the target particle size range, thus possessing both small size effect and high specific surface area; antioxidant stability is significantly enhanced; light conversion efficiency, film compatibility and long-term anti-aging performance are strong, and migration and aggregation are inhibited.

[0032] In some embodiments, specifically, the molecular formula of the benzotriazole monomer containing silicon atoms or carbon-carbon double bonds, hydroxyl groups, carboxyl groups, carbonyl groups, ester groups, or amide groups is:

[0033] Where R is a siloxane or other functional group, and n is in the range of 2 < n < 15.

[0034] In some embodiments, specifically, the molecular formula of the benzotriazole cyclide includes: , , , , , , , Any one or more combinations thereof.

[0035] In some embodiments, specifically, the high oxygen barrier protective layer comprises at least one of ethylene-vinyl alcohol copolymer or polyvinyl alcohol copolymer.

[0036] In some embodiments, specifically, the particle size of the light-converting micro-clusters is 100–160 nm; the particle size of the functional core is 80–110 nm; and the thickness of the shell is 20–50 nm.

[0037] This disclosure also provides a method for preparing the aforementioned light-converting micro-clusters, comprising the following steps: S1, dispersing benzotriazole monomers containing silicon atoms or other functional groups into nanoscale microemulsion droplets, and performing siloxane hydrolysis-condensation to form a functional core; S2, adding a shell material and a crosslinking agent / initiator to the microemulsion containing the functional core, initiating crosslinking of the shell material molecules, forming a dense coating on the surface of the functional core, and obtaining the light-converting micro-clusters.

[0038] This disclosure also provides an encapsulating film with downconversion capability, comprising at least one light-converting microparticle as described above and an organic polymer material, and comprising the following components by mass parts: 100 parts organic polymer material, 0.01-2 parts light-converting microparticle, 0.01-1.1 parts light stabilizer, 0.1-2 parts crosslinking agent, 0.1-2 parts co-crosslinking agent, and 0.1-1.2 parts silane coupling agent. The downconversion capability specifically refers to the ability to efficiently convert 280-380nm ultraviolet light into 400-600nm visible light.

[0039] In some embodiments, specifically, the thickness of the encapsulating film is 10 to 1000 μm, and the mass percentage of highly antioxidant and anti-migration optically convertible micro-clusters is 0.01 to 2 wt%.

[0040] In some embodiments, specifically, the organic polymer material includes any one or more combinations of thermoplastic polyolefins, polyvinyl butyral, polyolefin elastomers, polyurethanes, thermoplastic polyurethanes, polyacrylates, ethylene vinyl acetate copolymers, organosilicon, and EEA ionomers.

[0041] In some embodiments, specifically, the silane coupling agent includes any one or more combinations of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, and γ-chloropropylmethoxysilane.

[0042] In some embodiments, specifically, the crosslinking agent includes any one or more combinations of dicumyl peroxide, tert-butyl peroxide-2-ethylhexyl carbonate, 1,1-di(tert-butyl peroxide)-3,3,5-trimethylcyclohexane, tert-butyl peroxide-2-ethylhexanoate, tert-butyl peroxybenzoate, 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane, tert-butyl peroxyacetate, and 1,1-di(tert-butyl peroxide)cyclohexane.

[0043] In some embodiments, specifically, the co-crosslinking agent includes any one or more combinations of triallyl isocyanurate, triallyl cyanurate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, triallylamine, ethoxylated bisphenol A diacrylate, and ethoxylated bisphenol A dimethacrylate.

[0044] In some embodiments, specifically, the light stabilizer includes bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, poly-{[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidine)imino]-1,6-hexanediyl}, a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine alcohol, and 1,3-bis[(4-methoxy] [N-2,2,6,6-Tetramethylpiperidin-4-yl)amino]-2,4-bis(2,2,6,6-tetramethylpiperidin-4-oxy)propane, 4-benzoyloxy-2,2,6,6-tetramethylpiperidin, 2,2,6,6-tetramethyl-4-piperidinyl stearate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, any one or more combinations thereof.

[0045] This disclosure also provides a photovoltaic module, which, from top to bottom, includes glass, a first encapsulating film, a solar cell, a second encapsulating film, and a backsheet or glass; wherein the first encapsulating film is an encapsulating film with down-conversion capability as described above.

[0046] Example 1 includes the following scheme:

[0047] 1H-benzotriazole, potassium carbonate (catalyst), and 8-iodo-1-octene were added to a round-bottom flask. N,N-dimethylformamide (DMF) was added as a solvent. The mixture was stirred and heated at 80 °C for 5 h. After the reaction was completed, the mixture was cooled to room temperature, washed with saturated NH4Cl solution to remove DMF, extracted with ethyl acetate, dried over anhydrous Na2SO4 on the organic phase, filtered, and separated by column chromatography (petroleum ether PE / dichloromethane DCM = 1:5) to obtain compound 1.

[0048] Compound 1, Br2, and HBr were added to a round-bottom flask and heated under reflux at 130 °C for 18 h with stirring. After cooling, the mixture was washed with cold saturated KOH solution to remove excess Br2 and HBr, extracted with dichloromethane, dried over anhydrous Na2SO4, and subjected to column chromatography (PE / DCM = 1:5) to obtain compound 2.

[0049] p-Trimethoxysilylphenylboronic acid and potassium carbonate were added to a three-necked flask, and the mixture was evacuated and purged with nitrogen three times. Toluene / n-butanol / water was mixed with compound 2, and the mixture was transferred to a reaction flask under nitrogen protection. The reaction was carried out at 100°C for 1 h. After cooling to below 50°C, nitrogen was purged to remove oxygen, and Pd(PPh3)4 was quickly added. The mixture was sealed and heated to 100°C to continue the reaction for 12 h. After the reaction was completed, the mixture was cooled, dried over anhydrous Na2SO4, filtered, concentrated, and subjected to column chromatography (PE / DCM = 1:10) to give 2-(oct-8-en-1-yl)-4,7-bis(4-trimethoxysilylphenyl)-2H-benzotriazole.

[0050] Preparation of nucleosomes: 50 mg of 2-(oct-8-en-1-yl)-4,7-bis(4-trimethoxysilylphenyl)-2H-benzotriazole was dissolved in 2 mL of tetrahydrofuran (THF) and added dropwise to 10 mmol / L phosphate buffer (pH 6.5, containing 0.01 mol / L trifluoroacetic acid) containing 0.1 wt% sodium dodecyl sulfate (SDS). The mixture was sonicated at 0 °C (200 W, 20 kHz) for 10 min, reacted at 25 °C for 30 min, and collected by centrifugation (12000 rpm, 10 min).

[0051] EVOH coating: 200 mg EVOH was dissolved in a mixed solvent of 7 mL dimethyl sulfoxide (DMSO) and 3 mL water. After dissolving at 65 °C, 1 mL of the core microarray suspension was added, followed by 5 mL of deionized water. 0.50 mL of 10 wt% ammonium persulfate (APS) was added while stirring at 25 °C. After reacting for 2 hours, 0.5 mL of 0.1 mol / L hydroquinone was added. The mixture was centrifuged and washed 3 times to obtain EVOH shell-converted microspheres.

[0052] Components by weight: 100 parts polyolefin elastomer (POE); 0.2 parts 2,2,6,6-tetramethyl-4-piperidinyl stearate as light stabilizer; 0.6 parts tert-butyl peroxide-2-ethylhexyl carbonate as crosslinking agent; 0.4 parts triallyl isocyanurate as co-crosslinking agent; 0.9 parts γ-methacryloyloxypropyltrimethoxysilane and 0.3 parts EVOH shell light-converting microspheres as silane coupling agents.

[0053] Weigh the raw materials according to the components, mix them thoroughly, bake at 50℃ for 5 hours, let stand for 24 hours, and then pour them into the feed port of the screw extruder. The equipment temperature is 95℃. After heating and melting, filtering, and flowing through the distributor to the die head of the extruder, the materials are cast, embossed, cooled, slit, wound, and formed into a film. The glossy film has a basis weight of 400g / m².

[0054] Glass, high-transparency adhesive film, battery cells, light-converting adhesive film, and glass are stacked from bottom to top and then laminated using a laminator.

[0055] Example 2: A photovoltaic module was prepared using the same method as in Example 1. The difference from Example 1 is that the EVOH shell light-converting microspheres were 0.6 parts by weight.

[0056] Example 3: A photovoltaic module was prepared using the same method as in Example 1. The difference from Example 1 was that the EVOH shell light-converting microspheres were 0.9 parts by weight.

[0057] Example 4: Compared with Example 1, the difference is that the core of the light-converting microarray is coated with PVA, and the core microarray is prepared using the method of Example 1. The PVA shell coating method is shown below.

[0058] PVA coating: PVA-205 (88% degree of hydrolysis, 500-600 degree of polymerization) was dissolved in deionized water at 90 ℃ to prepare a 2-5 wt% solution, cooled to room temperature and filtered; the core micro-particle suspension (5 mg / mL) was added dropwise to the above PVA solution at a volume ratio of 1:5-1:10, and the mixture was magnetically stirred at 25 ℃ for 30 min to obtain a slightly blue emulsion. 0.5-2 wt% boric acid and 0.1M HCl were added to the emulsion to adjust the pH to 4-5, and the mixture was stirred at 25 ℃ for 1-2 h; then the mixture was centrifuged at 12000 rpm for 10 min and washed three times with deionized water to obtain PVA shell-converted microspheres.

[0059] Components by weight: 100 parts polyolefin elastomer (POE); 0.2 parts 2,2,6,6-tetramethyl-4-piperidinyl stearate as light stabilizer; 0.6 parts tert-butyl peroxide-2-ethylhexyl carbonate as crosslinking agent; 0.4 parts triallyl isocyanurate as co-crosslinking agent; 0.9 parts γ-methacryloyloxypropyltrimethoxysilane and 0.3 parts EVOH shell light-converting microspheres as silane coupling agents.

[0060] Weigh the raw materials according to the components, mix them thoroughly, bake at 50℃ for 5 hours, let stand for 24 hours, and then pour them into the feed port of the screw extruder. The equipment temperature is 95℃. After heating and melting, filtering, and flowing through the distributor to the die head of the extruder, the materials are cast, embossed, cooled, slit, wound, and formed into a film. The glossy film has a basis weight of 400g / m².

[0061] Glass, high-transparency adhesive film, battery cells, light-converting adhesive film, and glass are stacked from bottom to top and then laminated using a laminator.

[0062] Example 5: A photovoltaic module was prepared using the same method as in Example 4, except that the PVA shell light-converting microspheres were 0.6 parts by weight.

[0063] Example 6: A photovoltaic module was prepared using the same method as in Example 4, except that the PVA shell light-converting microspheres were 0.9 parts by weight.

[0064] Comparative Example 1: Photovoltaic modules were prepared using the same method as in Example 1, except that no light-converting reagent was included in the composition by weight.

[0065] Comparative Example 2: Photovoltaic modules were prepared using the same method as in Example 1. The difference from Example 1 is that, according to the weight composition, 2-(oct-8-en-1-yl)-4,7-bis(4-trimethoxysilylphenyl)-2H-benzotriazole is used as the phototransformation reagent.

[0066] Comparative Example 3: Photovoltaic modules were prepared using the same method as in Example 1, except that, according to the weight composition, 4,7-bis(4-(tert-butyl)phenyl)-2-octyl-2H-benzo[D][1,2,3]triazole was used as the light-converting agent.

[0067] As shown in the figure Figure 2 , 6 The light-converting adhesive film used is from Example 1. Figure 3 , 7 The light-converting adhesive film used is from Example 4. Figure 4 , 8 The light-converting adhesive film used was Comparative Example 2. Figure 5 , 9 The light-converting adhesive film used was Comparative Example 3.

[0068] Figure 2-5 In the middle, the samples, from top to bottom, are glass / transfer film / glass. After lamination using a laminator, the samples were placed in a UV aging chamber and cumulatively irradiated with 120 kWh / m². Figure 4 , 5 This is a small-molecule downconversion encapsulating film. During UV aging, oxygen invades from all sides, causing oxidation at the sample edges, and photoluminescence disappears under UV light. Figure 2 , 3 No oxidation was observed at the edges, indicating that the antioxidant light-converting agent can effectively inhibit oxidation.

[0069] Figure 6-9 In the sample, the left half is a light-converting adhesive film, and the right half is a high-transmittance film without a light-converting agent; after pressing at 90 ℃, no cross-linking occurred, followed by drying in a 60 ℃ oven for 7×24 h. Initially, a clear black line demarcated the two halves. After aging, Figure 6 , 7 Photoluminescence appears to the right of the dividing line, indicating that the small molecule light-converting agent has migrated; Figure 8 , 9 There was no photoluminescence to the right of the dividing line, confirming that the antioxidant can effectively inhibit migration during storage.

[0070] Light-converting films containing highly antioxidant and anti-migration light-converting micro-clusters effectively block oxygen intrusion, preventing edge oxidation and fluorescence quenching. Furthermore, under high-temperature storage conditions, the light-converting agent does not migrate to adjacent film layers, indicating good positional stability. In contrast, light-converting films without antioxidants exhibit significant oxidation and deactivation during aging and diffuse migration at high temperatures, affecting the reliability of photovoltaic modules.

[0071] The photovoltaic modules of Examples 1-6 and Comparative Examples 1-3 were tested and aged in a UV aging chamber. The specific data are shown in the table below.

[0072]

[0073] 180 kW·h / m 2 After UV aging, Comparative Example 1, without any added light-converting reagent, exhibited weak UV resistance with an efficiency decrease of up to 8.64%; Comparative Example 3, using a conventional small-molecule light-converting reagent, showed an efficiency decrease of 2.32%; and Comparative Example 2, employing an anti-migration small-molecule light-converting reagent, showed an efficiency decrease of 1.97%. In contrast, Examples 1-6 introduced highly antioxidant and anti-migration light-converting microclusters, with efficiency decreases all below 1.8%, significantly superior to the three comparative examples, demonstrating that the microclusters possess excellent UV aging resistance.

[0074] In summary, this high-antioxidant and anti-migration light-converting microparticle, encapsulating film, and photovoltaic module, through the core-shell structure of the light-converting microparticle, can efficiently convert 280-380nm ultraviolet light into 400-600nm visible light. Compared with small-molecule light-converting reagents, large-molecule light-converting microparticles can maintain a fixed position during the melt flow stage before lamination, without migration or gravity sedimentation. Moreover, the cross-linked shell has low oxygen permeability, which can simultaneously block the diffusion of oxygen and peroxide free radicals in the film to the functional core. After lamination, the microparticle core, cross-linked shell, and encapsulating film matrix can be covalently bonded to form a continuous three-dimensional network structure, anchoring the light-converting microparticles to the network nodes and achieving permanent fixation and barrier protection.

[0075] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A light-converting microcluster, characterized in that, include: The functional core and the shell covering its surface; The functional kernel includes chromophores with downconversion capabilities; The chromophore comprises benzotriazole monomers containing silicon atoms or carbon-carbon double bonds, hydroxyl groups, carboxyl groups, carbonyl groups, ester groups, and amide groups, which are hydrolyzed and condensed into cyclic macromolecules through silicon-oxygen bonds to obtain benzotriazole cyclized compounds. The shell is a high oxygen barrier protective layer; The light-converting micro-clusters are bonded to each other by silicon-oxygen bonds, forming oligomer core micro-clusters with ring or network structures.

2. The optically convertible microcell as described in claim 1, characterized in that, The molecular formula of the benzotriazole monomer containing silicon atoms or carbon-carbon double bonds, hydroxyl groups, carboxyl groups, carbonyl groups, ester groups, or amide groups is: ； Where R is a siloxane or other functional group, and n is in the range of 2 < n < 15.

3. The optically convertible microcell as described in claim 1, characterized in that, The molecular formula of the benzotriazole cyclide includes: 、 、 、 、 、 、 , Any one or more combinations thereof.

4. The optically convertible microcell as described in claim 1, characterized in that, The high oxygen barrier protective layer includes at least one of ethylene-vinyl alcohol copolymer or polyvinyl alcohol copolymer.

5. The optically convertible microcell as described in claim 1, characterized in that, The particle size of the optically converted micro-elements is 100–160 nm; The particle size of the functional core is 80–110 nm; The thickness of the shell is 20–50 nm.

6. A method for preparing optically convertible micro-clusters as described in any one of claims 1-5, characterized in that, Includes the following steps: S1, benzotriazole monomers containing silicon atoms or other functional groups are dispersed into nanoscale microemulsion droplets, and then subjected to siloxane hydrolysis-condensation to form a functional core; S2, add shell material and crosslinking agent / initiator to microemulsion containing functional core, initiate crosslinking of shell material molecules, form dense coating on the surface of functional core, and obtain light-converting microclusters.

7. An encapsulating film, characterized in that, It includes at least one optically convertible microcell and an organic polymer material as described in any one of claims 1-5, and comprises the following components by mass parts: 100 parts organic polymer material, 0.01-2 parts light-converting micro-particles, 0.01-1.1 parts light stabilizer, 0.1-2 parts crosslinking agent, 0.1-2 parts co-crosslinking agent, and 0.1-1.2 parts silane coupling agent.

8. The encapsulating film as described in claim 7, characterized in that, The thickness of the encapsulating film is 10-1000 μm, and the mass percentage of highly antioxidant and anti-migration optically active micro-groups is 0.01-2 wt%.

9. The encapsulating film as described in claim 7, characterized in that, The organic polymer material includes any one or more combinations of thermoplastic polyolefins, polyvinyl butyral, polyolefin elastomers, polyurethanes, thermoplastic polyurethanes, polyacrylates, ethylene vinyl acetate copolymers, organosilicon, and EEA ionomers.

10. A photovoltaic module, characterized in that, From top to bottom, it includes glass, first encapsulation film, battery cell, second encapsulation film, and backsheet or glass. Wherein, the first encapsulating film is the encapsulating film as described in any one of claims 7-9.

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