Light-conversion packaging adhesive film and preparation method thereof, and method for judging retention rate of light-conversion agent in light-conversion packaging adhesive film

Abstract

The invention provides a light-conversion packaging adhesive film, a preparation method thereof and a method for judging the retention rate of a light-conversion agent in the light-conversion packaging adhesive film. The light-conversion packaging adhesive film comprises a substrate light-conversion adhesive film layer, the surface, close to a battery piece, of the substrate light-conversion adhesive film layer is marked as a first surface, and a UV indicator layer is locally arranged on the first surface; the substrate light conversion adhesive film layer comprises a light conversion agent, and the UV indicator layer comprises a UV indicator; and the ultraviolet absorption wave bands of the UV indicator and the light conversion agent are at least partially overlapped. According to the light conversion packaging adhesive film, the retention rate condition of the light conversion agent can be intuitively reflected through the color change of the UV indicator layer. By means of the design, direct detection of the state of the light conversion agent in the packaging adhesive film is avoided, meanwhile, the evaluation process is simplified, performance monitoring of the light conversion packaging adhesive film is more convenient and accurate, and therefore the problem that in the prior art, the loss degree of the light conversion agent in the light conversion packaging adhesive film is difficult to judge is solved.

Description

Technical Field

[0001] This invention relates to the field of light transfer film technology, and more specifically, to a light transfer encapsulation film and its preparation method, and a method for determining the retention rate of the light transfer agent in the light transfer encapsulation film. Background Technology

[0002] In the photovoltaic industry, phototransfer encapsulation films are widely used as an important encapsulation material because they can convert invisible light in the solar spectrum into visible light, thereby improving the photoelectric conversion efficiency of photovoltaic modules. However, in actual use, the light-converting agent inside existing phototransfer encapsulation films may gradually lose its activity over time and due to environmental factors, leading to a decrease in light conversion efficiency. This process usually occurs in the enclosed environment inside the photovoltaic module; therefore, real-time monitoring of the light-converting agent and quantitative assessment of its failure state have become an industry challenge. Because the timing and extent of phototransfer film failure within photovoltaic modules are difficult to determine, it is difficult to implement corresponding solutions based on the degree of light-converting agent loss.

[0003] In summary, it is particularly important to develop an optical transfer encapsulation film that can determine the degree of loss of the optical transfer agent through special detection methods. Summary of the Invention

[0004] The main objective of this invention is to provide a phototransfer encapsulation film and its preparation method, as well as a method for determining the retention rate of the light transfer agent in the phototransfer encapsulation film, so as to solve the problem in the prior art that it is difficult to determine the degree of loss of the light transfer agent in the phototransfer encapsulation film.

[0005] To achieve the above objectives, according to one aspect of the present invention, a phototransfer encapsulation film is provided. The phototransfer encapsulation film includes a substrate phototransfer film layer, the surface of the substrate phototransfer film layer near the solar cell is referred to as a first surface, and a UV indicator layer is partially disposed on the first surface; the substrate phototransfer film layer includes a light-converting agent, and the UV indicator layer includes a UV indicator; the UV indicator and the light-converting agent have at least partially overlapping ultraviolet absorption bands.

[0006] Furthermore, the aforementioned UV indicator layer includes multiple patterned blocks, which are dot-matrix, strip-shaped, or corner blocks; the area of ​​each patterned block is 0.5 cm². 2 ~25cm 2 Preferably 5cm 2 ~15cm 2 The distance between two adjacent patterned blocks is 0.3m to 1.5m, preferably 0.4m to 0.8m.

[0007] Furthermore, the patterned blocks are composed of UV indicators, and the thickness of the UV indicator layer is 0.1μm to 20μm, preferably 0.5μm to 12μm.

[0008] Further, the patterned area is a transparent film containing a UV indicator, the thickness of which is 0.05mm to 2mm, preferably 0.5mm to 1mm; by weight, the substrate phototransfer film layer comprises: 80 to 100 parts of a first matrix resin; 0.1 to 3 parts of a first crosslinking agent; 0.02 to 5 parts of a first co-crosslinking agent; 0.02 to 2 parts of a first silane coupling agent; 0.005 to 2 parts of a first light stabilizer; 0.005 to 2 parts of a light-converting agent; and / or, by weight, the transparent film comprises: 80 to 100 parts of a second matrix resin; 0.1 to 3 parts of a second crosslinking agent; 0.02 to 5 parts of a second co-crosslinking agent; 0.02 to 2 parts of a second silane coupling agent; 0.005 to 2 parts of a second light stabilizer; 0.0.05~2 parts of UV indicator; wherein the UV indicator is a photochromic compound, preferably one or more of spiropyran compounds and their derivatives, spiroxazine compounds and their derivatives, wherein the spiropyran compound is 1',3',3'-trimethyl-6-nitrobenzospiropyran, and the spiroxazine compound is 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphtho[2,1-b][1,4]oxazine]; and / or, the light-converting agent is selected from one or more of organic fluorescent light-converting agents, rare earth compound light-converting agents, and quantum dot light-converting agents; and / or, the first matrix resin and the second matrix resin each The first crosslinking agent and the second crosslinking agent are each independently selected from any one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, polyvinyl butyral, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and ethylene-butyl acrylate copolymer; and / or, the first crosslinking agent and the second crosslinking agent are each independently selected from 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl peroxide-3,5,5-trimethylhexanoate, 4,4-di(tert-pentylperoxy)valerate, and 3,3-di(tert-butylperoxy)valerate. The first co-crosslinking agent and the second co-crosslinking agent are each independently selected from any one or more of tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propionyl oxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, and ethoxylated trimethylolpropane triacrylate; and / or the first silane coupling agent and the second silane coupling agent are each independently selected from γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and diethylaminomethyl... The light stabilizer comprises any one or more of the following: γ-methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; and / or, the first light stabilizer and the second light stabilizer are each independently selected from any one or more of the following: bis-2,2,6,6-tetramethylpiperidinol sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, N,N'-bis-(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and polymers of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol.

[0009] According to another aspect of the present invention, a method for preparing the aforementioned phototransfer encapsulating film is provided, comprising: mixing raw materials including a first matrix resin, a first crosslinking agent, a first co-crosslinking agent, a first silane coupling agent, a first light stabilizer, and a light transfer agent, and then casting and extruding them to form a substrate phototransfer film layer; partially coating a UV indicator on a first surface of the substrate phototransfer film layer, or partially bonding a transparent film to the first surface of the substrate phototransfer film layer to form a UV indicator layer; and before forming the UV indicator layer, performing a pre-crosslinking treatment on a local area in the substrate phototransfer film layer in which the UV indicator layer is disposed, wherein the pre-crosslinking degree of the pre-crosslinking treatment is ≥20%.

[0010] Furthermore, the degree of pre-crosslinking in the pre-crosslinking treatment is 35% to 65%, preferably 55% to 60%.

[0011] Furthermore, the aforementioned UV indicator layer includes multiple patterned blocks; the preparation process of forming the UV indicator layer by lamination includes: mixing raw materials including a second matrix resin, a second crosslinking agent, a second co-crosslinking agent, a second silane coupling agent, a second light stabilizer, and a UV indicator, and then casting and extruding them to form an initial transparent film; cutting the initial transparent film into transparent films that match the patterned blocks; and partially laminating the transparent film onto the first surface of the substrate phototransfer film layer by heating and lamination; wherein, the areal density of the initial transparent film is 50 g / m³. 2 ~200g / m 2 The thickness is 0.05mm~2mm.

[0012] According to another aspect of the present invention, a method for determining the retention rate of light transfer agent in a light transfer encapsulation film is provided, comprising: step S1, sequentially laminating a front glass, the aforementioned light transfer encapsulation film, a solar cell, a back encapsulation film, and a backsheet to obtain a photovoltaic module; step S2, testing the b0 of the region Lab where the UV indicator is located in the photovoltaic module. Value; Step S3, perform a first aging treatment and a second aging treatment on the photovoltaic module respectively. After the first aging treatment, place the photovoltaic module in an ultraviolet light environment for a certain period of time, and then test the b1 value of the region Lab where the UV indicator is located in the photovoltaic module. Value; After the photovoltaic module underwent the second aging treatment and was placed in an ultraviolet light environment for a certain period of time, the b2 value of the Lab region containing the UV indicator in the photovoltaic module was tested. Value; Define Δb1 =b0 -b1 Δb2 =b0 -b2 Retention rate of light transfer agent in light transfer encapsulation film = 100% - (Δb) x / M)×100%, where x is 1 or 2; the method for determining M includes: when the light transfer encapsulating film does not contain a light transfer agent, testing the b0 of the region Lab where the UV indicator is located. The value was determined by placing the photovoltaic module in a UV environment for a certain period of time, and then testing the b value of the region Lab containing the UV indicator in the photovoltaic module. Value, (b0) -b The absolute value of the value is M.

[0013] Further, in step S3 above, a UV lamp that responds to the UV indicator is selected and irradiated for a fixed time in the area where the UV indicator is located on the photovoltaic module after the first aging treatment. The b1 value of the area Lab where the UV indicator is located in the photovoltaic module is then tested. Value; After irradiating the area where the UV indicator is located on the photovoltaic module for a fixed period of time following the second aging treatment, the b2 value of the area Lab in the photovoltaic module where the UV indicator is located is tested. Value; preferably, the fixed time is 5s~10s; and / or, the conditions for the first aging treatment are 100kWh / m 2 ~130kWh / m 2 The conditions for the second aging treatment were 220 kWh / m³. 2 ~250kWh / m 2 .

[0014] Furthermore, the above-mentioned judgment method determines the failure state of the light-converting agent by the retention rate of the light-converting agent in the phototransfer encapsulation film. The judgment criteria include: when Δb x When M ≥ 0, the retention rate of the light transfer agent in the phototransfer encapsulation film is ≤ 0%, indicating that the light transfer agent in the phototransfer encapsulation film has completely failed; when 0 < Δb x When Δb < M, 0% < corresponds to a retention rate of the light transfer agent in the phototransfer encapsulation film < 100%, indicating that some of the light transfer agent in the phototransfer encapsulation film has failed; when Δb x When =0, the retention rate of the light transfer agent in the corresponding phototransfer encapsulation film is 100%, which means that there is no loss of the light transfer agent in the phototransfer encapsulation film, that is, the light transfer agent has not failed at all.

[0015] By applying the technical solution of this invention, the phototransfer encapsulation film in this application can intuitively reflect the retention rate of the light-converting agent through the color change of the UV indicator layer. The selection of the UV indicator, which at least partially overlaps with the UV absorption band of the light-converting agent, ensures that when both are exposed to the same UV radiation, the indicator's response change directly reflects the change in the photochemical activity of the light-converting agent. As photovoltaic modules are used in outdoor environments, the light-converting agent gradually deactivates under long-term UV irradiation. The color change of the UV indicator layer can quantify this process, thus providing an effective means of monitoring the degree of light-converting agent loss. This design not only avoids direct detection of the state of the light-converting agent inside the encapsulation film but also simplifies the evaluation process, making the performance monitoring of the phototransfer encapsulation film more convenient and accurate. Therefore, the technical solution of this invention significantly improves the efficiency and accuracy of photovoltaic module performance monitoring, providing a scientific basis for the maintenance and upgrading of photovoltaic modules. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0017] As analyzed in the background section of this application, there is a problem in the prior art that it is difficult to determine the degree of loss of the light transfer agent in the light transfer encapsulation film. This application provides a light transfer encapsulation film and its preparation method, as well as a method for determining the retention rate of the light transfer agent in the light transfer encapsulation film.

[0018] In a typical embodiment of this application, a phototransfer encapsulation film is provided. The phototransfer encapsulation film includes a substrate phototransfer film layer. The surface of the substrate phototransfer film layer near the solar cell is referred to as the first surface. A UV indicator layer is partially disposed on the first surface. The substrate phototransfer film layer includes a light-converting agent, and the UV indicator layer includes a UV indicator. The UV absorption bands of the UV indicator and the light-converting agent at least partially overlap.

[0019] The phototransfer encapsulation film in this application can intuitively reflect the retention rate of the light-converting agent through the color change of the UV indicator layer. The selection of the UV indicator and its overlap with the UV absorption band of the light-converting agent ensures that when both are exposed to the same UV radiation, the indicator's response change directly reflects the photochemical activity change of the light-converting agent. As photovoltaic modules are used in outdoor environments, the light-converting agent gradually deactivates under long-term UV irradiation. The color change of the UV indicator layer can quantify this process, thus providing an effective means of monitoring the degree of light-converting agent loss. This design not only avoids direct detection of the state of the light-converting agent inside the encapsulation film but also simplifies the evaluation process, making the performance monitoring of the phototransfer encapsulation film more convenient and accurate. Therefore, the technical solution of this invention significantly improves the efficiency and accuracy of photovoltaic module performance monitoring, providing a scientific basis for the maintenance and upgrading of photovoltaic modules.

[0020] In one embodiment of this application, the UV indicator layer includes multiple patterned blocks, which are dot-matrix, strip-shaped, or corner blocks; the area of ​​each patterned block is 0.5 cm². 2 ~25cm 2 Preferably 5cm 2 ~15cm 2 The distance between two adjacent patterned blocks is 0.3m to 1.5m, preferably 0.4m to 0.8m.

[0021] The aforementioned UV indicator layer comprises multiple patterned blocks, designed as dot matrix, strip, or corner blocks. Preferably, the area of ​​each patterned block is within a specific range to improve the visibility and accuracy of the marked area. The optimal distance between adjacent patterned blocks improves the uniformity of UV indicator distribution and reduces mutual interference caused by excessively close proximity. Excessive distance can lead to components with insufficient UV indicator areas during continuous production, limiting the information obtained during testing and affecting product consistency. By designing the UV indicator layer as patterned blocks, multiple detection points can be created within the photovoltaic module, making the assessment of the light conversion agent retention rate more comprehensive and accurate. Each block, as an independent monitoring unit, can reflect the light conversion agent status in different locations, providing more information for subsequent maintenance and optimization.

[0022] In one embodiment of this application, the patterned area is composed of a UV indicator, and the thickness of the UV indicator layer is 0.1μm to 20μm, preferably 0.5μm to 12μm.

[0023] Optimizing the thickness of the UV indicator layer not only improves its stability and reliability within the phototransfer encapsulation film but also reduces the risk of decreased detection sensitivity due to excessively thin layers and interlayer delamination due to excessively thick layers. Precisely controlling the UV indicator layer thickness helps improve its response speed and intensity to ultraviolet light, thus providing more accurate data feedback in photovoltaic module aging monitoring. Furthermore, the optimized thickness of the UV indicator layer not only enhances its mechanical strength but also improves its durability in complex environments, thereby increasing the monitoring accuracy and lifespan of the entire phototransfer encapsulation film.

[0024] In one embodiment of this application, the patterned area is a transparent film containing a UV indicator, the thickness of which is 0.05mm to 2mm, preferably 0.5mm to 1mm; by weight, the substrate phototransfer film layer comprises: 80 to 100 parts of a first matrix resin; 0.1 to 3 parts of a first crosslinking agent; 0.02 to 5 parts of a first co-crosslinking agent; 0.02 to 2 parts of a first silane coupling agent; 0.005 to 2 parts of a first light stabilizer; 0.005 to 2 parts of a light-converting agent; and / or, by weight, the transparent film comprises: 80 to 100 parts of a second matrix resin; 0.1 to 3 parts of a second crosslinking agent; 0.02 to 5 parts of a second co-crosslinking agent; 0.02 to 2 parts of a second silane coupling agent; 0.005 to 2 parts of a second light stabilizer; 0.0.05~2 parts of UV indicator; wherein the UV indicator is a photochromic compound, preferably one or more of spiropyran compounds and their derivatives, spiroxazine compounds and their derivatives, wherein the spiropyran compound is 1',3',3'-trimethyl-6-nitrobenzospiropyran, and the spiroxazine compound is 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphtho[2,1-b][1,4]oxazine]; and / or, the light-converting agent is selected from one or more of organic fluorescent light-converting agents, rare earth compound light-converting agents, and quantum dot light-converting agents; and / or, the first matrix resin and the second matrix resin each The first crosslinking agent and the second crosslinking agent are each independently selected from any one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, polyvinyl butyral, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and ethylene-butyl acrylate copolymer; and / or, the first crosslinking agent and the second crosslinking agent are each independently selected from 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl peroxide-3,5,5-trimethylhexanoate, 4,4-di(tert-pentylperoxy)valerate, and 3,3-di(tert-butylperoxy)valerate. The first co-crosslinking agent and the second co-crosslinking agent are each independently selected from any one or more of tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propionyl oxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, and ethoxylated trimethylolpropane triacrylate; and / or the first silane coupling agent and the second silane coupling agent are each independently selected from γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and diethylaminomethyl... The light stabilizer comprises any one or more of the following: γ-methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; and / or, the first light stabilizer and the second light stabilizer are each independently selected from any one or more of the following: bis-2,2,6,6-tetramethylpiperidinol sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, N,N'-bis-(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and polymers of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol.

[0025] Further, the preferred organic fluorescent converting agent is selected from any one or more of 3-ethyl-7-hydroxy-4,8-dimethyl-coumarin, 6,7-dihydroxycoumarin, 4-methyl-7-dimethylaminecoumarin, 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, 2,2'-(4,4'-stilbene-)bisbenzoxazole, sodium stilbene biphenyl disulfonate, sodium 4,4'-bis(4,6-diphenylaminotriazinyl-2-amino)stilbene-2,2'-disulfonate, bistriazinamine stilbene derivatives, and 1-(p-methanesulfonylphenyl)-3-(p-chlorophenyl)pyrazoline.

[0026] Furthermore, Ce³ is preferred as a rare earth compound light-converting agent. + :YAG、Ce³ + ,Yb³ + :YAG、NaYF4:Tb³ + ,Yb³ + YVO4:Bi³ + ,Tm³ + ,Yb³ + NaYF4:Er³ + ,Tm³ + ,Yb³ + Any one or more of the following; preferably, the quantum dot-type light-converting agent is an inorganic quantum dot, preferably any one or more of CdSe, CdS, ZnSe, and CsPbX3, wherein X = Cl, Br, or I.

[0027] The preferred UV indicator transparent film being within the above-mentioned range helps improve the sensitivity and reliability of the marking area, thereby enhancing the accurate monitoring of light conversion agent failure. The preferred proportions of the first matrix resin, first crosslinking agent, first co-crosslinking agent, first silane coupling agent, first light stabilizer, and light conversion agent in the substrate phototransfer film layer being within the above-mentioned range helps to improve its UV response characteristics while maintaining the film's basic performance, making it more stable and durable in the photovoltaic module operating environment. The preferred UV indicator, through its sensitive response to specific ultraviolet bands, translates into a visible color change, providing direct evidence for monitoring the light conversion agent's effectiveness. Furthermore, the preferred types of light conversion agents help expand the functionality and adaptability of the film, enabling it to effectively convert ultraviolet light under different environmental conditions. The independent selection of materials such as the first and second matrix resins, and the first and second crosslinking agents, helps to promote the complementarity and optimization of the performance between the substrate and the indicator layer, enhancing the balance of the entire phototransfer encapsulation film in terms of weather resistance, transparency, and UV conversion efficiency, thereby improving its applicability and effectiveness in photovoltaic module encapsulation. In summary, by optimizing the above material types, ratios, and UV indicator layers, not only is the stability and conversion efficiency of the light transfer film in the basic scheme enhanced, but an intuitive failure monitoring mechanism is also introduced, improving the convenience and accuracy of photovoltaic module maintenance and effectively reducing the risk of module performance degradation due to light transfer agent failure.

[0028] In another typical embodiment of this application, a method for preparing the aforementioned phototransfer encapsulating film is provided, comprising: mixing raw materials including a first matrix resin, a first crosslinking agent, a first co-crosslinking agent, a first silane coupling agent, a first light stabilizer, and a light transfer agent, and then casting and extruding them to form a substrate phototransfer film layer; partially coating a UV indicator on a first surface of the substrate phototransfer film layer, or partially bonding a transparent film to a first surface of the substrate phototransfer film layer to form a UV indicator layer; and before forming the UV indicator layer, performing a pre-crosslinking treatment on the local area of ​​the substrate phototransfer film layer in which the UV indicator layer is disposed, wherein the pre-crosslinking degree of the pre-crosslinking treatment is ≥20%.

[0029] This application provides a method for preparing a light transfer encapsulating film with UV indicator function. This method involves adding a specific UV indicator to the light transfer encapsulating film and locally depositing it beneath the light transfer layer of the film, ensuring that the UV indicator accurately reflects the aging state of the light transfer agent. The selection of the UV indicator must at least partially overlap with the UV absorption band of the light transfer agent. This characteristic allows the UV indicator to simulate the response of the light transfer agent to ultraviolet light, thus enabling a direct assessment of the light transfer agent retention rate during the aging process of the light transfer encapsulating film by observing or detecting the color change of the UV indicator. The precise control of the above preparation process ensures that the encapsulating film not only possesses excellent light conversion efficiency but also has the function of monitoring its own aging state, significantly enhancing the reliability and maintainability of photovoltaic modules. Furthermore, by pre-crosslinking the target area before forming the UV indicator layer, the fluidity and chemical reactivity of this area during the lamination process are effectively limited. This avoids the risk of indicator dispersion due to excessive film fluidity in this area during lamination, enhancing the integrity of the indicator area and thus accurately reflecting the light transfer agent retention rate, further improving the accuracy and reliability of monitoring.

[0030] In one embodiment of this application, the degree of pre-crosslinking in the pre-crosslinking treatment is 35% to 65%, preferably 55% to 60%.

[0031] Preferably, the degree of pre-crosslinking is within the above range. This not only reduces the problem of excessive flow of UV indicator during lamination due to insufficient pre-crosslinking, but also reduces the risk of appearance defects or delamination from the glass in this area of ​​the component due to excessive pre-crosslinking. This further improves the accuracy of its use as a criterion for evaluating the retention rate of light conversion agent.

[0032] In one embodiment of this application, the UV indicator layer includes multiple patterned blocks; the preparation process of forming the UV indicator layer by lamination includes: mixing raw materials including a second matrix resin, a second crosslinking agent, a second co-crosslinking agent, a second silane coupling agent, a second light stabilizer, and a UV indicator, and then casting and extruding them to form an initial transparent film; cutting the initial transparent film into transparent films that match the patterned blocks; and partially laminating the transparent film onto the first surface of the substrate phototransfer film layer by heating and lamination; wherein, the areal density of the initial transparent film is 50 g / m³. 2 ~200g / m 2 The thickness is 0.05mm~2mm.

[0033] The aforementioned UV indicator bonds more firmly to the substrate light conversion agent film layer. Furthermore, by precisely controlling the material composition and structure of the UV indicator layer, its stability within the photovoltaic module encapsulation film can be ensured, reducing excessive flow or dispersion during module manufacturing. In addition, by controlling the areal density and thickness, the UV indicator layer's response speed and sensitivity to ultraviolet light can be improved, thereby increasing the accuracy of determining the light conversion agent retention rate. These parameter settings not only facilitate real-time monitoring of the light conversion agent's effectiveness but also guide maintenance and replacement strategies, extending the lifespan of photovoltaic modules and improving their economic efficiency and environmental adaptability.

[0034] In another typical embodiment of this application, a method for determining the retention rate of the light transfer agent in a light transfer encapsulation film is provided. The method includes: step S1, sequentially laminating the front glass, the aforementioned light transfer encapsulation film, the solar cell, the back encapsulation film, and the backsheet to obtain a photovoltaic module; step S2, testing the b0 value of the region Lab where the UV indicator is located in the photovoltaic module. Value; Step S3, perform a first aging treatment and a second aging treatment on the photovoltaic module respectively. After the first aging treatment, place the photovoltaic module in an ultraviolet light environment for a certain period of time, and then test the b1 value of the region Lab where the UV indicator is located in the photovoltaic module. Value; After the photovoltaic module underwent the second aging treatment and was placed in an ultraviolet light environment for a certain period of time, the b2 value of the Lab region containing the UV indicator in the photovoltaic module was tested. Value; Define Δb1 =b0 -b1 Δb2 =b0 -b2 Retention rate of light transfer agent in light transfer encapsulation film = 100% - (Δb) x / M)×100%, where x is 1 or 2; the method for determining M includes: when the light transfer encapsulating film does not contain a light transfer agent, testing the b0 of the region Lab where the UV indicator is located. The value was determined by placing the photovoltaic module in a UV environment for a certain period of time, and then testing the b value of the region Lab containing the UV indicator in the photovoltaic module. Value, (b0) -b The absolute value of the value is M.

[0035] This application provides a method for determining the retention rate of light-converting agent in a light-transfer encapsulating film. The core of this method lies in using a UV indicator in a specific region within the encapsulating film as a monitoring tool. By quantitatively analyzing the changes in the b-value within the indicator region, the retention status of the light-converting agent during the operation of the photovoltaic module is reflected. First, the encapsulating film is laminated with other components to form a complete photovoltaic module, and the b0 value in the Lab color space of the region where the UV indicator is located in the initial state is determined. This value reflects the state of the light transfer agent in the unaged light transfer encapsulating film. Subsequently, the photovoltaic modules were subjected to aging treatments under different conditions. After aging, the modules were placed back in a UV environment, and the b1 value in the Lab color space of the UV indicator area was measured and recorded after the same exposure time. value and b2 Value. Calculated by b0 Value and b1 value or b2 The difference between values ​​Δb1 and Δb2 By combining this with a pre-set baseline value M, the retention rate of the light-converting agent can be accurately evaluated. The value of M is determined by exposing the area containing the UV indicator to the same UV light without the light-converting agent, in the Lab color space b... The range of change in the value is determined and used as the maximum theoretical range of change. In the above technical solution, the selection of the UV indicator and its positioning within the encapsulating film ensure that the indicator can sensitively respond to changes in ultraviolet light associated with the light-converting agent, thus visually displaying the retention status of the light-converting agent through color changes. This method not only provides the ability to qualitatively assess the aging state of the light-converting encapsulating film but also achieves accurate measurement of the light-converting agent retention rate by introducing quantitative indicators, thereby helping to monitor and maintain the performance of photovoltaic modules in a timely manner and extend their service life.

[0036] In one embodiment of this application, in step S3 above, a UV lamp that responds to the UV indicator is selected and irradiated for a fixed time in the area where the UV indicator is located on the photovoltaic module after the first aging treatment, and the b1 value of the area Lab where the UV indicator is located in the photovoltaic module is tested. Value; After irradiating the area where the UV indicator is located on the photovoltaic module for a fixed period of time following the second aging treatment, the b2 value of the area Lab in the photovoltaic module where the UV indicator is located is tested. Value; preferably, the fixed time is 5s~10s; and / or, the conditions for the first aging treatment are 100kWh / m 2 ~130kWh / m 2 The conditions for the second aging treatment were 220 kWh / m³. 2 ~250kWh / m 2 .

[0037] A UV lamp that responds to the UV indicator is preferred, with a wavelength range matching the light-converting agent, enabling precise excitation of visually recognizable changes in the UV indicator. Photovoltaic modules that have undergone different aging treatments are irradiated for a fixed time, and the change in the b-value (denoted as b1) of Lab in the region containing the UV indicator in the module is tested. and b2 This method helps improve the accuracy of quantifying the color change of UV indicators, thereby accurately assessing the retention rate of the light transfer agent within the encapsulation film. Specifically, the UV indicator layer gradually changes color according to the received UV dose and frequency when the photovoltaic module is exposed to ultraviolet radiation. This change is accurately recorded, and by comparing it with the original color, the loss status of the light transfer agent can be quantified. Under the optimized first and second aging treatments, the stability of the light transfer agent at different aging stages can be compared, providing data support for photovoltaic module maintenance strategies. In particular, this differentiated aging treatment and quantitative detection method allows us to identify changes in the light transfer encapsulation film under early and severe failure states, providing a scientific basis for preventative maintenance and optimized operation of the module. Therefore, by monitoring the color change of the indicator, information about the activity of the light transfer agent can be indirectly obtained. The operation is simple, requires no disassembly of the photovoltaic module, reduces testing costs, and improves evaluation efficiency.

[0038] In one embodiment of this application, the above-mentioned judgment method determines the failure state of the light transfer agent by the retention rate of the light transfer agent in the phototransfer encapsulation film. The judgment criteria include: when Δb x When M ≥ 0, the retention rate of the light transfer agent in the phototransfer encapsulation film is ≤ 0%, indicating that the light transfer agent in the phototransfer encapsulation film has completely failed; when 0 < Δb x When Δb < M, 0% < corresponds to a retention rate of the light transfer agent in the phototransfer encapsulation film < 100%, indicating that some of the light transfer agent in the phototransfer encapsulation film has failed; when Δb x When =0, the retention rate of the light transfer agent in the corresponding phototransfer encapsulation film is 100%, which means that there is no loss of the light transfer agent in the phototransfer encapsulation film, that is, the light transfer agent has not failed at all.

[0039] The above-mentioned failure condition judgment criteria are determined by setting Δb. The range of values ​​not only quantifies the degree of loss of the light-converting agent in the light-converting encapsulation film but also provides a clear evaluation benchmark. Simultaneously, it simplifies and simplifies the evaluation process, reducing uncertainty caused by subjective judgment. During the service life of the light-converting encapsulation film, as the light-converting agent gradually degrades, its ultraviolet absorption capacity in specific wavelengths decreases, causing a color change in the UV indicator layer that matches that wavelength. This color change reflects the remaining activity of the light-converting agent. Therefore, by monitoring the color difference change of the UV indicator layer, the actual state of the light-converting agent within the encapsulation film can be understood in a timely and accurate manner, thereby predicting the long-term performance stability of the component and guiding maintenance and optimization strategies.

[0040] The beneficial effects that this application can achieve will be further illustrated below with reference to embodiments and comparative examples.

[0041] Example 1

[0042] 90 parts of POE, 2 parts of the first crosslinking agent 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 3 parts of the first co-crosslinking agent tris(2-hydroxyethyl)isocyanurate triacrylate, 1 part of the first silane coupling agent γ-aminopropyltriethoxysilane, 1 part of the first light stabilizer bis-2,2,6,6-tetramethylpiperidin sebacate, and 1 part of the light-converting agent 3-ethyl-7-hydroxy-4,8-dimethylcoumarin were mixed and then cast and extruded to form a base. A phototransfer film layer is formed. A localized area of ​​the aforementioned phototransfer film layer where a UV indicator layer is to be formed undergoes pre-crosslinking treatment with a pre-crosslinking degree of 35%. A photochromic compound, 1',3',3'-trimethyl-6-nitrobenzospiropyran, is locally coated onto the first surface of the phototransfer film layer (the surface of the phototransfer film layer closest to the solar cell) to form a UV indicator layer with a thickness of 10 μm. This layer consists of multiple strip-patterned blocks, each with an area of ​​5 cm². 2 The distance between two adjacent strip patterned blocks is 0.6m, resulting in a phototransfer encapsulation film.

[0043] A photovoltaic module is obtained by sequentially laminating the front glass, light transfer encapsulation film, solar cells, back encapsulation film, and backsheet.

[0044] Example 2

[0045] 90 parts of POE, 2 parts of the first crosslinking agent 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 3 parts of the first co-crosslinking agent tris(2-hydroxyethyl)isocyanurate triacrylate, 1 part of the first silane coupling agent γ-aminopropyltriethoxysilane, 1 part of the first light stabilizer sebacic acid bis-2,2,6,6-tetramethylpiperidinol ester, and 1 part of the light transfer agent 3-ethyl-7-hydroxy-4,8-dimethylcoumarin were mixed and then cast and extruded to form a base phototransfer film layer.

[0046] A mixture comprising 90 parts of POE, 2 parts of the second crosslinking agent 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 3 parts of the second co-crosslinking agent tris(2-hydroxyethyl)isocyanurate triacrylate, 1 part of the second silane coupling agent γ-aminopropyltriethoxysilane, 1 part of the second light stabilizer sebacic acid bis-2,2,6,6-tetramethylpiperidinol ester, and 1 part of the photochromic compound 1',3',3'-trimethyl-6-nitrobenzospiropyran was cast and extruded to form an initial transparent film. The initial transparent film was then cut into transparent films matching strip patterned areas (the UV indicator layer pre-set on the substrate phototransfer film layer consists of multiple strip patterned areas), with a thickness of 1 mm and an areal density of 100 g / m³. 2 .

[0047] In the aforementioned substrate phototransfer film layer, a local area where a UV indicator layer is to be set is subjected to pre-crosslinking treatment with a pre-crosslinking degree of 45%. The aforementioned transparent film is locally bonded to the first surface of the substrate phototransfer film layer (the surface of the substrate phototransfer film layer close to the battery cell) to form a UV indicator layer. The strip patterned blocks of the UV indicator layer are subjected to pre-crosslinking treatment with a pre-crosslinking degree of 45% to obtain a phototransfer encapsulation film.

[0048] A photovoltaic module is obtained by sequentially laminating the front glass, light transfer encapsulation film, solar cells, back encapsulation film, and backsheet.

[0049] Example 3

[0050] The difference from Example 1 is that the area of ​​the strip patterned area is 15cm². 2 This process yields a light transfer encapsulation film, ultimately resulting in a photovoltaic module.

[0051] Example 4

[0052] The difference from Example 1 is that the area of ​​the strip patterned area is 0.5 cm². 2 This process yields a light transfer encapsulation film, ultimately resulting in a photovoltaic module.

[0053] Example 5

[0054] The difference from Example 1 is that the area of ​​the strip patterned area is 25 cm². 2 This process yields a light transfer encapsulation film, ultimately resulting in a photovoltaic module.

[0055] Example 6

[0056] The difference from Example 1 is that the distance between two adjacent strip patterned blocks is 0.8m to obtain the light transfer encapsulation film, and finally obtain the photovoltaic module.

[0057] Example 7

[0058] The difference from Example 1 is that the distance between two adjacent strip patterned blocks is 0.3m, resulting in a light transfer encapsulation film, and finally a photovoltaic module.

[0059] Example 8

[0060] The difference from Example 1 is that the pre-crosslinking degree of the UV indicator layer is 60%, resulting in a light transfer encapsulation film, and finally a photovoltaic module.

[0061] Example 9

[0062] The difference from Example 1 is that the pre-crosslinking degree of the UV indicator layer is 20%, resulting in a light transfer encapsulation film, and finally a photovoltaic module.

[0063] Example 10

[0064] The difference from Example 1 is that the pre-crosslinking degree of the UV indicator layer is 65%, resulting in a light transfer encapsulation film, and finally a photovoltaic module.

[0065] Comparative Example 1

[0066] The difference from Example 1 is that the phototransfer encapsulation film is a regular phototransfer encapsulation film (without adding UV indicator).

[0067] A photovoltaic module is obtained by sequentially laminating the front glass, light transfer encapsulation film, solar cells, back encapsulation film, and backsheet.

[0068] Comparative Example 2

[0069] The difference from Example 2 is that the phototransfer encapsulation film is a regular phototransfer encapsulation film (without adding UV indicator).

[0070] A photovoltaic module is obtained by sequentially laminating the front glass, light transfer encapsulation film, solar cells, back encapsulation film, and backsheet.

[0071] Comparative Example 3

[0072] The difference from Example 1 is that, before forming the UV indicator layer, the local area in the substrate phototransfer film layer where the UV indicator layer is to be set is not pre-crosslinked, resulting in a phototransfer encapsulation film, and finally a photovoltaic module.

[0073] Performance testing:

[0074] The b0 value of the Lab region, where the UV indicator is located, in the above examples and comparative examples was measured using a colorimeter. Value (Note: b0) and below b1 b2 (All values ​​are averages of three test points evenly distributed across the region).

[0075] After irradiating the area containing the UV indicator in the photovoltaic modules of the above embodiments and comparative examples with a 365nm UV light source (an LED UV lamp was selected as the test light source), the b1 value of the area Lab containing the UV indicator in the above embodiments and comparative examples was tested again. b2 value.

[0076] Lab in b1 The sample was tested at 120 kWh / m 2 The test value, b2 The sample was tested at 240 kWh / m 2 The test values ​​were obtained by using a UV metal halide lamp as the UV light source in the above aging test, and the light intensity was set to 150W / m² during the experiment. 2 After the experiment, the samples were exposed to ultraviolet light for 5 seconds.

[0077] Define Δb1 =b0 -b1 Δb2 =b0 -b2 , Δb (Range: 0~35) is used to determine the retention rate of the light transfer agent in the phototransfer encapsulation film. Retention rate % = 100% - (Δb) X The upper and lower limits of the sample were tested using (35)×100 (where x is 1 or 2), and the evaluation data are shown in Table 1.

[0078] Table 1

[0079]

[0080] The test results of the above embodiments and comparative examples are listed in Table 2.

[0081] Table 2

[0082]

[0083] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0084] The phototransfer encapsulation film in this application can intuitively reflect the retention rate of the light-converting agent through the color change of the UV indicator layer. The selection of the UV indicator, which partially overlaps with the UV absorption band of the light-converting agent, ensures that when both are exposed to the same UV radiation, the indicator's response directly reflects the change in the photochemical activity of the light-converting agent. As photovoltaic modules are used in outdoor environments, the light-converting agent gradually deactivates under long-term UV exposure. The color change of the UV indicator layer can quantify this process, thus providing an effective means of monitoring the degree of light-converting agent loss. This design not only avoids direct detection of the state of the light-converting agent inside the encapsulation film but also simplifies the evaluation process, making the performance monitoring of the phototransfer encapsulation film more convenient and accurate. Therefore, the technical solution of this invention significantly improves the efficiency and accuracy of photovoltaic module performance monitoring, providing a scientific basis for the maintenance and upgrading of photovoltaic modules.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A phototransfer encapsulation film, characterized in that, The light transfer encapsulation film includes a substrate light transfer encapsulation film layer, and the surface of the substrate light transfer encapsulation film layer near the solar cell is referred to as the first surface. A UV indicator layer is partially disposed on the first surface. The substrate phototransfer film layer includes a phototransfer agent, and the UV indicator layer includes a UV indicator; The UV indicator and the light-converting agent have at least partially overlapping UV absorption bands.

2. The phototransfer encapsulation film according to claim 1, characterized in that, The UV indicator layer includes multiple patterned blocks, which are dot matrix, strip, or corner blocks; The area of ​​each patterned block is 0.5 cm². 2 ~25cm 2 Preferably 5cm 2 ~15cm 2 ; The distance between two adjacent patterned blocks is 0.3m to 1.5m, preferably 0.4m to 0.8m.

3. The phototransfer encapsulation film according to claim 2, characterized in that, The patterned area is composed of the UV indicator, and the thickness of the UV indicator layer is 0.1μm~20μm, preferably 0.5μm~12μm.

4. The phototransfer encapsulation film according to claim 2, characterized in that, The patterned area is a transparent film containing a UV indicator, and the thickness of the UV indicator layer is 0.05mm to 2mm, preferably 0.5mm to 1mm; The substrate phototransfer film layer comprises, by weight parts: 80-100 parts of the first matrix resin; 0.1 to 3 parts of the first crosslinking agent; 0.02 to 5 parts of the first crosslinking agent; 0.02 to 2 parts of the first silane coupling agent; 0.005 to 2 parts of the first light stabilizer; 0.005 to 2 parts of the light-converting agent; And / or, by weight, the transparent film comprises: 80-100 parts of the second matrix resin; 0.1 to 3 parts of the second crosslinking agent; 0.02 to 5 parts of the second crosslinking agent; 0.02 to 2 parts of the second silane coupling agent; 0.005 to 2 parts of a second light stabilizer; 0.005 to 2 parts of UV indicator; The UV indicator is a photochromic compound, preferably one or more of spiropyran compounds and their derivatives, and spiroxazine compounds and their derivatives. The spiropyran compound is 1',3',3'-trimethyl-6-nitrobenzospiropyran, and the spiroxazine compound is 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphtho[2,1-b][1,4]oxazine]. And / or, the light-converting agent is selected from any one or more of organic fluorescent light-converting agents, rare earth compound light-converting agents, and quantum dot light-converting agents; And / or, the first matrix resin and the second matrix resin are each independently selected from any one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, polyvinyl butyral, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and ethylene-butyl acrylate copolymer; And / or, the first crosslinking agent and the second crosslinking agent are each independently selected from any one or more of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, di-tert-butylperoxide, dicumyl peroxide, tert-butyl peroxide-3,5,5-trimethylhexanoate, n-butyl 4,4-di(tert-pentylperoxy)valerate, and ethyl 3,3-di(tert-butylperoxy)butyrate; And / or, the first co-crosslinking agent and the second co-crosslinking agent are each independently selected from any one or more of tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, and ethoxylated trimethylolpropane triacrylate; And / or, the first silane coupling agent and the second silane coupling agent are each independently selected from any one or more of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, diethylaminomethyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; And / or, the first light stabilizer and the second light stabilizer are each independently selected from any one or more of the following: bis-2,2,6,6-tetramethylpiperidinol sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, N,N'-bis-(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and polymers of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol.

5. A method for preparing the phototransfer encapsulating film according to any one of claims 1 to 4, characterized in that, The preparation method includes: The raw materials, including a first matrix resin, a first crosslinking agent, a first co-crosslinking agent, a first silane coupling agent, a first light stabilizer, and a light transfer agent, are mixed and then cast and extruded to form a base light transfer film layer. A UV indicator layer is formed by partially coating a UV indicator onto the first surface of the substrate phototransfer film layer, or by partially bonding a transparent film to the first surface of the substrate phototransfer film layer. Before forming the UV indicator layer, a local area in the substrate phototransfer film layer where the UV indicator layer is disposed is pre-crosslinked, and the degree of pre-crosslinking of the pre-crosslinking treatment is ≥20%.

6. The preparation method according to claim 5, characterized in that, The degree of pre-crosslinking in the pre-crosslinking treatment is 35% to 65%, preferably 55% to 60%.

7. The preparation method according to claim 5, characterized in that, The UV indicator layer includes multiple patterned blocks; the fabrication process of forming the UV indicator layer by bonding includes: The raw materials, including a second matrix resin, a second crosslinking agent, a second co-crosslinking agent, a second silane coupling agent, a second light stabilizer, and a UV indicator, are mixed and then cast and extruded to form an initial transparent film. The initial transparent film is cut into transparent films that match the patterned blocks; The transparent adhesive film is partially bonded to the first surface of the substrate phototransfer adhesive film layer by heating and bonding. The areal density of the initial transparent adhesive film is 50 g / m³. 2 ~200g / m 2 The thickness is 0.05mm~2mm.

8. A method for determining the retention rate of the light transfer agent in the phototransfer encapsulating film according to any one of claims 1 to 3, characterized in that, The determination method includes: Step S1: The front glass, the light transfer encapsulation film according to any one of claims 1 to 3, the solar cell, the back encapsulation film and the back sheet are laminated sequentially to obtain a photovoltaic module; Step S2, test the b0 of region Lab where the UV indicator is located in the photovoltaic module. value; Step S3: The photovoltaic module is subjected to a first aging treatment and a second aging treatment. After the first aging treatment, the photovoltaic module is placed in an ultraviolet light environment for a certain period of time, and the b1 value of the region Lab where the UV indicator is located in the photovoltaic module is tested. Value; After the photovoltaic module undergoing the second aging treatment is placed in an ultraviolet light environment for a certain period of time, the b2 value of the Lab region containing the UV indicator in the photovoltaic module is tested. value; Define Δb1 =b0 -b1 Δb2 =b0 -b2 The retention rate of the light-converting agent in the light transfer encapsulation film = 100% - (Δb) x / M)×100%, where x is 1 or 2; The method for determining M includes: when the light transfer encapsulating film does not contain a light transfer agent, testing the b0 of the region Lab where the UV indicator is located in the component. The value was determined by placing the photovoltaic module in a UV environment for a certain period of time, and then testing the b value of the region Lab containing the UV indicator in the photovoltaic module. Value, (b0) -b The absolute value of the value is M.

9. The judgment method according to claim 8, characterized in that, In step S3, a UV lamp that responds to the UV indicator is selected and irradiated for a fixed time in the area of ​​the photovoltaic module where the UV indicator is located after the first aging treatment. The b1 value of the area Lab where the UV indicator is located in the photovoltaic module is then tested. Value; The area of ​​the photovoltaic module with the UV indicator after the second aging treatment is irradiated for a fixed time, and the b2 value of the area Lab where the UV indicator is located in the photovoltaic module is tested. value; Preferably, the fixed time is 5s to 10s; And / or, the conditions for the first aging treatment are 100 kWh / m 2 ~130kWh / m 2 The conditions for the second aging treatment were 220 kWh / m³. 2 ~250kW·h / m 2 .

10. The determination method according to claim 8, characterized in that, The failure state of the light-converting agent is determined by the retention rate of the light-converting agent in the light transfer encapsulation film. The determination criteria include: When Δb x When M ≥ 0%, the retention rate of the light-converting agent in the light transfer encapsulation film is ≤ 0%, indicating that the light-converting agent in the light transfer encapsulation film has completely failed. When 0 < Δb x When M < 0%, the retention rate of the light-converting agent in the light transfer encapsulation film is < 100%, indicating that some of the light-converting agent in the light transfer encapsulation film has failed. When Δb x When =0, the retention rate of the light-converting agent in the light transfer encapsulation film is 100%, which means that the light-converting agent in the light transfer encapsulation film is not lost, that is, the light-converting agent has not failed at all.

Images