Composite adhesive film and photovoltaic module

Abstract

A composite adhesive film and a photovoltaic module, which relate to the technical field of photovoltaics. The composite adhesive film comprises a cut-off layer (110), a first isolation layer (120) and a lower light conversion layer (130), which are sequentially stacked, wherein the cut-off layer (110) includes a cut-off agent and is used for controlling a spectrum irradiation range; the lower light conversion layer (130) has a lower light conversion function and is used for converting an ultraviolet band into a visible light band; and the first isolation layer (120) is used for isolating the cut-off layer (110) and the lower light conversion layer (130) from being fused with each other under a high-temperature state. The photovoltaic module comprises a cell, wherein the composite adhesive film is provided on the surface of at least one side of the cell; and the lower light conversion layer (130) of the composite adhesive film is close to the cell, and the cut-off layer (110) thereof is away from the cell.

Description

Composite adhesive film and photovoltaic module

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202310762532.8, filed with the State Intellectual Property Office of China on June 26, 2023, entitled “A composite adhesive film and photovoltaic module,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure relates to the field of photovoltaic technology, and in particular to a composite adhesive film and a photovoltaic module. Background Art

[0004] Solar cells generally have a good spectral response in the visible light band. At the same time, photoconversion materials can convert light in a certain band into light in another band. Therefore, specific photoconversion materials can be used to cover the surface of solar cells to convert ultraviolet and infrared light in sunlight into visible light, thereby achieving the purpose of improving the cell conversion efficiency.

[0005] For stability reasons, photoconverters need to operate within their light intensity window. If they are exposed to high doses of light, they will degrade faster. Currently, photoconverters on the surface of solar cells are typically directly exposed to sunlight of all wavelengths. When exposed to high-intensity light that exceeds their tolerance, the photoconverters degrade faster, and the output power of the component decreases.

[0006] Therefore, how to solve the attenuation problem of light conversion films is an issue that needs urgent attention.

[0007] Summary of the Invention

[0008] The present disclosure provides a composite adhesive film, which includes a cutoff layer, a first isolation layer and a lower light conversion layer stacked in sequence, wherein the cutoff layer contains a cutoff agent for controlling the spectral irradiation range; the lower light conversion layer has a downward light conversion function for converting the ultraviolet band into the visible light band, and the first isolation layer is used to isolate the cutoff layer and the lower light conversion layer from fusing with each other under high temperature conditions.

[0009] The present disclosure provides a composite adhesive film, which includes a cutoff layer, a first isolation layer and a light conversion layer stacked in sequence. The cutoff layer contains a cutoff agent for controlling the spectral irradiation range; the light conversion layer has a light conversion function for converting ultraviolet and / or infrared bands into visible light bands, and the first isolation layer is used to prevent the cutoff layer and the light conversion layer from fusing with each other under high temperature conditions.

[0010] Optionally, the light conversion layer is an upper light conversion layer, and the upper light conversion layer has an upper light conversion function for converting an infrared band into a visible light band.

[0011] Optionally, the light conversion layer has both upward light conversion and downward light conversion functions, and is used to convert ultraviolet and infrared bands into visible light bands.

[0012] Optionally, the light transmittance of the cut-off layer is greater than or equal to the light transmittance of the lower light conversion layer, and the light transmittance of the first isolation layer is greater than or equal to the light transmittance of the lower light conversion layer; or

[0013] The light transmittance of the cut-off layer is greater than or equal to the light transmittance of the light conversion layer, and the light transmittance of the first isolation layer is greater than or equal to the light transmittance of the light conversion layer.

[0014] Optionally, the gram weight of the cut-off layer is ≤260 g / m2, the gram weight of the first isolation layer is ≤80 g / m2, and the gram weight of the lower light conversion layer is ≤260 g / m2.

[0015] Optionally, an upper light conversion layer and a second isolation layer are stacked between the first isolation layer and the lower light conversion layer. The upper light conversion layer has an upward light conversion function and is used to convert the infrared band into a visible light band. The first isolation layer is used to isolate the cutoff layer and the upper light conversion layer from merging with each other, and the second isolation layer is used to isolate the upper light conversion layer and the lower light conversion layer from merging with each other.

[0016] Optionally, the composite adhesive film is provided with a cutoff layer, a first isolation layer, an upper light conversion layer, a second isolation layer and a lower light conversion layer in sequence; or

[0017] The composite adhesive film is sequentially provided with a cut-off layer, a first isolation layer, a lower light conversion layer, a second isolation layer and an upper light conversion layer.

[0018] Optionally, the light transmittance of the second isolation layer is greater than or equal to the light transmittance of the lower light conversion layer, and the light transmittance of the upper light conversion layer is greater than or equal to the light transmittance of the lower light conversion layer.

[0019] Optionally, the cut-off layer has a gram weight of ≤200 g / m2, the first isolation layer and the second isolation layer have a gram weight of ≤80 g / m2 respectively, and the lower light conversion layer and the upper light conversion layer have a gram weight of ≤200 g / m2 respectively.

[0020] Optionally, the addition amount of the cut-off agent in the cut-off layer is 0.1% to 2%.

[0021] Optionally, the softening points of the first isolation layer and the second isolation layer are higher than the softening points of the cut-off layer, the lower light conversion layer, and the upper light conversion layer.

[0022] Optionally, the first isolation layer and the second isolation layer are the same or different;

[0023] Optionally, the isolation layer is selected from one or more of modified PE (polyethylene) materials, ethylene polar materials, and ethylene copolymer non-polar materials;

[0024] Optionally, the fluidity of the isolation layer at a high temperature is lower than that of the cut-off layer, the lower light conversion layer, and the upper light conversion layer.

[0025] Optionally, the high temperature refers to a temperature above 40°C.

[0026] Optionally, the layers of the composite adhesive film are independent of each other and are composited into an integrated structure.

[0027] The present disclosure provides a method for preparing a composite adhesive film, comprising the following steps: stacking and laying each layer in sequence and combining them into one;

[0028] Optionally, during the manufacturing process of the photovoltaic module, each layer is sequentially laid on the cell sheet so that the composite adhesive film is arranged on the photovoltaic module; or

[0029] The above layers are used to prepare an integrated composite adhesive film.

[0030] The present disclosure provides a photovoltaic module, comprising a cell, wherein the upper surface and / or lower surface of the cell is provided with the aforementioned composite adhesive film; the light conversion layer of the composite adhesive film is close to the cell, and the cutoff layer is away from the cell;

[0031] Optionally, the lower light conversion layer of the composite adhesive film is close to the cell, and the cutoff layer is far away from the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments.

[0033] FIG1 is a schematic structural diagram of a composite adhesive film provided in a first embodiment of the present disclosure;

[0034] FIG2 is a schematic structural diagram of a composite adhesive film provided in a second embodiment of the present disclosure.

[0035] Icon: 110 - cut-off layer; 120 - first isolation layer; 130 - lower light conversion layer; 210 - upper light conversion layer; 220 - second isolation layer; 230 - lower light conversion layer. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present disclosure will be described below with reference to the accompanying drawings in the embodiments of the present disclosure.

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Generally, the components of the embodiments of the present disclosure described and shown in the drawings herein can be arranged and designed in a variety of different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the present disclosure as claimed, but rather merely represents selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0040] In the description of this disclosure, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is typically placed when in use. These terms are intended solely to facilitate the description of this disclosure and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. Furthermore, the terms "first," "second," etc., etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.

[0042] Currently, coating the surface of solar cells with photoconverters (photoconverters) can enhance cell efficiency by converting light from other wavelengths into visible light. Photoconverters are functionally classified into two types: upconverters (which convert infrared light into visible light) and downconverters (which convert ultraviolet light into visible light).

[0043] Photoconverters are categorized by material into three types: inorganic, organic, and inorganic-organic hybrids. Organic photoconverters offer excellent conversion efficiency but are unstable and prone to decomposition. Inorganic photoconverters offer poor conversion efficiency but are relatively stable. Both have distinct advantages and disadvantages, so inorganic-organic hybrids are currently the most commonly used photoconverters.

[0044] Light-conversion coatings typically contain a light-converting agent, a layer with a light-converting function. When exposed to high-intensity light exceeding its tolerance, the light-converting material will decay more rapidly. Therefore, for stability reasons, the light-converting agent must operate within a light intensity window. Effectively controlling the incident light dose, keeping the light-converting agent operating within the appropriate dose window, maximizes output while preventing accelerated degradation.

[0045] The applicant discovered that a method for controlling the incident light dose is to use a cutoff agent. By controlling the type and dosage of the cutoff agent, the wavelength and dose of the incident light can be controlled. Therefore, a cutoff film layer containing the cutoff agent can be superimposed on a light conversion film layer and regulated based on the performance of the underlying light conversion film layer, acting like a gate.

[0046] However, if the two film layers are directly bonded together, the cut-off agent and the light-converting agent will diffuse into each other, and a chemical reaction will occur upon contact, causing each other to fail.

[0047] In order to ensure the long-term effect of the light conversion agent, the present disclosure introduces a composite structure of a cutoff film layer + an isolation layer + a light conversion film layer. This design scheme can not only maximize the light conversion effect, but also maintain it for a long time, thereby significantly improving the output power and reliability of the component.

[0048] The purpose of the present disclosure is to provide a composite adhesive film and photovoltaic module that can maintain a high light conversion effect for a long time, ensure the maximum light conversion effect, and significantly improve the output power and reliability of the module.

[0049] An embodiment of the present disclosure provides a composite adhesive film, which includes a cutoff layer, a first isolation layer and a lower light conversion layer stacked in sequence. The cutoff layer contains a cutoff agent for controlling the spectral irradiation range; the lower light conversion layer has a downward light conversion function for converting the ultraviolet band into the visible light band, and the first isolation layer is used to isolate the cutoff layer and the lower light conversion layer from fusing with each other under high temperature conditions.

[0050] In an optional embodiment, the composite adhesive film includes a cutoff layer, a first isolation layer and a lower light conversion layer stacked in sequence, the cutoff layer is an adhesive film containing a cutoff agent and used to control the spectral irradiation range; the lower light conversion layer is an adhesive film with a downward light conversion function and used to convert the ultraviolet band into the visible light band, and the first isolation layer is used to isolate the cutoff layer and the lower light conversion layer from fusion with each other under high temperature conditions.

[0051] In an optional embodiment, the composite adhesive film includes a cutoff layer, a first isolation layer and a light conversion layer stacked in sequence, wherein the cutoff layer contains a cutoff agent for controlling the spectral irradiation range; the light conversion layer has a light conversion function for converting the ultraviolet and / or infrared bands into the visible light band, and the first isolation layer is used to isolate the cutoff layer and the light conversion layer from fusion at high temperature.

[0052] In an optional embodiment, the composite adhesive film includes a cutoff layer, a first isolation layer and a light conversion layer stacked in sequence, wherein the cutoff layer is an adhesive film containing a cutoff agent and is used to control the spectral irradiation range; the light conversion layer is an adhesive film with a light conversion function and is used to convert the ultraviolet and / or infrared bands into the visible light band, and the first isolation layer is used to isolate the cutoff layer and the light conversion layer from fusion with each other under high temperature conditions.

[0053] In the above implementation process, the cutoff layer is superimposed on the lower light conversion layer. When sunlight irradiates the composite adhesive film, the cutoff layer first cuts off part of the wavelength band light, controls the spectral irradiation range passing through the cutoff layer, and the light conversion layer then converts the ultraviolet wavelength band light in the remaining wavelength band light into visible light, so that the output power and reliability of the photovoltaic module can be greatly improved. The present disclosure uses the cutoff layer to control the wavelength band and dose of the incident light irradiated to the lower light conversion layer, so that the light conversion agent in the lower light conversion layer is within the appropriate dose window, which can not only obtain the maximum light conversion efficiency, but also avoid the accelerated decomposition of the light conversion agent, so that a high light conversion effect can be maintained for a long time, ensuring the maximization of the light conversion effect; and the isolation layer is used to isolate the cutoff layer and the lower light conversion layer, so as to avoid the cutoff layer and the lower light conversion layer adhesive film from fusion under high temperature, thereby avoiding the cutoff agent in the cutoff layer and the light conversion agent in the lower light conversion layer from diffusing with each other, and chemically reacting after contact, causing each other to fail and affect the cutoff and light conversion effects, so that the component maintains a high output power.

[0054] In an optional embodiment, the light conversion layer is an upper light conversion layer, which has an upper light conversion function and is used to convert the infrared band into the visible light band;

[0055] Optionally, the light conversion layer has both upward light conversion and downward light conversion functions, and is used to convert ultraviolet and infrared bands into visible light bands.

[0056] In an optional embodiment, the light transmittance of the cut-off layer is greater than or equal to the light transmittance of the lower light conversion layer, and the light transmittance of the first isolation layer is greater than or equal to the light transmittance of the lower light conversion layer.

[0057] In an optional embodiment, the light transmittance of the cut-off layer is greater than or equal to the light transmittance of the light conversion layer, and the light transmittance of the first isolation layer is greater than or equal to the light transmittance of the light conversion layer.

[0058] In the above implementation process, the transmittance of the cutoff layer is determined by the dosage and formula of the cutoff agent. The initial power of the component to which the composite film is applied is mainly determined by the lower light conversion layer. The transmittance of the lower light conversion layer directly determines the power gain of the component. The transmittance of all layers on the lower light conversion layer is not less than the transmittance of the lowest lower light conversion layer, so that the lower light conversion layer can maximize its transmittance and light conversion effect.

[0059] In an optional embodiment, the grammage of the cut-off layer is ≤260 g / m2, the grammage of the first isolation layer is ≤80 g / m2, and the grammage of the lower light conversion layer is ≤260 g / m2.

[0060] In some embodiments, the cut-off layer has a grammage of ≤260 g / m2, such as ≤255 g / m2, ≤250 g / m2, ≤240 g / m2, ≤230 g / m2, ≤220 g / m2, ≤210 g / m2, ≤200 g / m2, ≤190 g / m2, ≤180 g / m2, etc. In some embodiments, the cut-off layer has a grammage of ≥100 g / m2, such as ≥110 g / m2, ≥120 g / m2, ≥130 g / m2, ≥140 g / m2, ≥150 g / m2, etc.

[0061] In some embodiments, the first isolation layer has a grammage of ≤80 g / m2, such as ≤78 g / m2, ≤75 g / m2, ≤72 g / m2, ≤70 g / m2, ≤68 g / m2, ≤65 g / m2, ≤60 g / m2, etc. In some embodiments, the first isolation layer has a grammage of ≥40 g / m2, ≥42 g / m2, ≥44 g / m2, ≥46 g / m2, 48 g / m2, etc.

[0062] In some embodiments, the grammage of the light conversion layer is ≤260 g / m2, e.g., ≤255 g / m2, ≤250 g / m2, ≤240 g / m2, ≤230 g / m2, ≤220 g / m2, ≤210 g / m2, ≤200 g / m2, ≤190 g / m2, ≤180 g / m2, etc. In some embodiments, the grammage of the cut-off layer is ≥100 g / m2, e.g., ≥110 g / m2, ≥120 g / m2, ≥130 g / m2, ≥140 g / m2, ≥150 g / m2, etc.

[0063] In the above implementation process, if the weight of each layer of the composite film is too large, it will affect the light transmittance, which in turn will affect the response effect of the photovoltaic module to sunlight.

[0064] In an optional embodiment, an upper light conversion layer and a second isolation layer are stacked between the first isolation layer and the lower light conversion layer. The upper light conversion layer has an upward light conversion function and is used to convert the infrared band into a visible light band. The first isolation layer is used to isolate the cutoff layer and the upper light conversion layer from merging with each other, and the second isolation layer is used to isolate the upper light conversion layer and the lower light conversion layer from merging with each other.

[0065] In an optional embodiment, the composite adhesive film is sequentially provided with a cutoff layer, a first isolation layer, an upper light conversion layer, a second isolation layer and a lower light conversion layer; or

[0066] The composite adhesive film is sequentially provided with a cut-off layer, a first isolation layer, a lower light conversion layer, a second isolation layer and an upper light conversion layer.

[0067] In the above implementation process, the upper cutoff layer cuts off part of the wavelength bands of sunlight according to the light conversion effects of the first light conversion layer and the upper light conversion layer in the lower layer, thereby controlling the irradiance of the incident light on the light conversion layer. The upper light conversion layer converts infrared light into visible light, and the lower light conversion layer converts ultraviolet light into visible light. The upward light conversion is performed first, and then the technologically mature downward light conversion is performed to realize the utilization of multi-band light in sunlight; the first isolation layer plays the role of isolating the mutual diffusion of the cutoff agent in the cutoff layer and the up-conversion agent in the upper light conversion layer under high temperature environment, and the second isolation layer plays the role of isolating the mutual diffusion of the up-conversion agent in the upper light conversion layer and the down-conversion agent in the lower light conversion layer, thereby achieving the effect of improving the reliability and power of the component.

[0068] In an optional embodiment, the light transmittance of the second isolation layer is greater than or equal to the light transmittance of the lower light conversion layer, and the light transmittance of the upper light conversion layer is greater than or equal to the light transmittance of the lower light conversion layer.

[0069] In an optional embodiment, the cut-off layer has a gram weight of ≤200 g / m2, the first isolation layer and the second isolation layer have a gram weight of ≤80 g / m2 respectively, and the lower light conversion layer and the upper light conversion layer have a gram weight of ≤200 g / m2 respectively.

[0070] In an optional embodiment, the amount of the cut-off agent added to the cut-off layer is 0.1% to 2%.

[0071] In the above implementation process, the wavelength and dose of the incident light to the light conversion layer are controlled by controlling the type and dose of the cut-off agent in the cut-off layer. In an optional embodiment, the cut-off layer is an adhesive film containing a cut-off agent for controlling the spectral irradiation range.

[0072] In an optional embodiment, the light conversion layer is an adhesive film having a light conversion function for converting ultraviolet and / or infrared bands into visible light bands.

[0073] In an optional embodiment, the softening points of the first isolation layer and the second isolation layer are higher than the softening points of the cut-off layer, the lower light conversion layer, and the upper light conversion layer.

[0074] In the above implementation process, the first isolation layer and the second isolation layer play an isolation role, preventing the adhesive films from fusing with each other under high temperature conditions, and can also be composited with adjacent adhesive films into one body.

[0075] In an optional embodiment, the first isolation layer and the second isolation layer are the same or different;

[0076] In an optional embodiment, the isolation layer is selected from one or more of modified PE (polyethylene) materials, ethylene polar materials, and olefin copolymer non-polar materials;

[0077] In an optional embodiment, the fluidity of the isolation layer at a high temperature is lower than that of the cut-off layer, the lower light conversion layer, and the upper light conversion layer.

[0078] In an optional embodiment, the high temperature refers to a temperature above 40°C.

[0079] In an optional embodiment, the layers of the composite film are independent of each other and are composited into an integral structure.

[0080] In the above implementation process, the layers of the composite film are independent of each other, so that each layer can play its own function and role, and the composite film is combined into one, thereby playing the role of light transmission and encapsulation.

[0081] The present disclosure provides a method for preparing a composite adhesive film, comprising the following steps: stacking and laying each layer in sequence and combining them into one.

[0082] During the manufacturing process of the photovoltaic module, the layers are sequentially laid on the cell sheet so that the composite adhesive film is arranged on the photovoltaic module; or

[0083] The various layers are used to produce an integrated composite film.

[0084] The disclosed embodiment provides a photovoltaic module, which includes a cell, at least one side of which is provided with the composite film provided by the first aspect, the lower light conversion layer of the composite film is close to the cell, and the cutoff layer is far away from the cell.

[0085] In the above implementation process, the photovoltaic module uses the composite film to first cut off part of the band light, and then converts the ultraviolet band light or the ultraviolet band light and infrared band light in the remaining band light into visible light, so that the battery cell can perform high-efficiency photoelectric conversion.

[0086] Please refer to Figure 1. This embodiment provides a composite adhesive film, which includes a cutoff layer 110, a first isolation layer 120 and a light conversion layer stacked in sequence. The cutoff layer 110 is used to cut off light in a first wavelength band to control the spectral illumination range. The light conversion layer is used to convert light in a second wavelength band into visible light. The first wavelength band and the second wavelength band are different. The first isolation layer 120 is used to isolate the cutoff layer 110 and the light conversion layer from fusion at high temperature, affecting the cutoff and light conversion effects.

[0087] In the embodiments of the present disclosure, the first wavelength band and the second wavelength band generally refer to light with wavelengths that do not overlap at all or partially overlap. The first wavelength band and the second wavelength band generally do not fall within the visible light range, or most of the wavelengths do not fall within the visible light range. "High temperature" refers to a temperature above 40°C.

[0088] In the disclosed embodiment, the light conversion layer can be an upper light conversion layer with an upward light conversion function or a lower light conversion layer with a downward light conversion function. The upper light conversion layer is used to convert infrared light into visible light, and the lower light conversion layer 230 is used to convert ultraviolet light into visible light. The upper cutoff layer 110, based on the light conversion effect of the lower light conversion layer, cuts off at least a portion of the sunlight except for the second wavelength and visible light, thereby controlling the irradiance of the incident light on the light conversion layer. The light conversion layer converts infrared light or ultraviolet light into visible light. The isolation layer serves to isolate the cutoff agent and the light conversion agent from interdiffusion in a high-temperature environment, thereby improving the reliability and power of the component.

[0089] As an embodiment, the light conversion layer is an upper light conversion layer, and the corresponding first band light is at least part of the light in the sunlight except the second band light and visible light. For example, the first band light cut off by the cutoff layer 110 is part of the infrared band light, and the second band light converted by the upper light conversion layer is the remaining infrared band light; or, the light conversion layer is a lower light conversion layer 130, and the corresponding first band light is at least part of the light in the sunlight except the second band light and visible light. For example, the first band light cut off by the cutoff layer 110 is part of the ultraviolet band light, and the second band light converted by the lower light conversion layer is the remaining ultraviolet band light.

[0090] In the present disclosure, "infrared light" refers to light in the band (wavelength range) of 760 to 2500 nm, "ultraviolet light" refers to light in the band (wavelength range) of 200 to 380 nm, and "visible light" refers to light in the band (wavelength range) of 380 to 760 nm.

[0091] In this embodiment, the light conversion layer is a lower light conversion layer 130, which is used to convert ultraviolet wavelength light into visible light. The ultraviolet wavelength light that can be converted by the lower light conversion layer 130 is the aforementioned second wavelength light. Accordingly, the first wavelength range of the cutoff layer 110 is adjusted based on the second wavelength range, so that the lower light conversion layer 130 can better convert the second wavelength light. In other embodiments, the light conversion layer can also be an upper light conversion layer, and the infrared wavelength light that can be converted by the upper light conversion layer is the second wavelength light.

[0092] In the disclosed embodiment, the composite film has a weight of ≤600g / m2, the cutoff layer 110 has a weight of ≤260g / m2, the first isolation layer 120 has a weight of ≤80g / m2, and the light conversion layer has a weight of ≤260g / m2. In this embodiment, the composite film has a weight of 450g / m2, the cutoff layer 110 has a weight of 200g / m2, the first isolation layer 120 has a weight of 50g / m2, and the lower light conversion layer 130 has a weight of 200g / m2.

[0093] In some embodiments of the present disclosure, cutoff layer 110 is a film containing a cutoff agent. For example, the cutoff agent can be added to any of a variety of films, such as EVA (Ethylene Vinyl Acetate Copolymer), EPE (Pearl Cotton), POE (Polyethylene Octene Co-elastomer), and PVB (Polyvinyl Butyral). Bifacial, double-glass modules require improved water resistance, and POE or PVB materials are typically used to form the cutoff layer 110. For monofacial, single-wave modules, a cutoff agent can be added to EVA, EPE, or POE films to form the cutoff layer 110. The amount of cutoff agent added to the cutoff layer 110 is generally 0.1% to 2%, for example, 0.1%, 0.5%, 0.7%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, or 2%, or any intermediate value between these two values.

[0094] The cut-off layer 110 in the present disclosure can be a commercially available cut-off layer, which is usually an ordinary adhesive film containing a cut-off agent, such as ParknShop high-cut-off adhesive film, Foster high-cut-off adhesive film, Swick high-cut-off 556 / 557 adhesive film, Saiwu C22Z adhesive film, Haiyouwei high-cut-off adhesive film, etc. The cut-off layer 110 can also be homemade. The cut-off layer 110 controls the wavelength of the first wavelength of light by controlling the dosage or formula of the cut-off agent according to the use requirements of the light-converting agent (the wavelength requirement of the second wavelength of light). For example, the lower light-converting layer can only convert ultraviolet wavelength light (second wavelength light) with a wavelength of 330 to 380 nm, and cannot convert ultraviolet band light with a wavelength of 280 to 330 nm. Then the cut-off layer 110 needs to add a corresponding cut-off agent to cut off this part of the light (first wavelength light) with a wavelength of 280 to 330 nm.

[0095] In some embodiments of the present disclosure, the light conversion layer is a film with a downward light conversion function. The light conversion material is typically placed in the EPE composite layer (the EPE composite layer is a three-layer structure, with the first layer being an EVA layer, the second layer being a POE layer, and the third layer being an EVA layer) in the layer structure close to the solar cell (the third layer of the EVA layer) to prevent refraction and other factors from affecting the light conversion effect. In this embodiment, the light conversion layer is a film containing a downward light conversion agent, namely, the lower light conversion layer 130. In other embodiments, the light conversion layer is a film containing an upward light conversion agent, namely, the upper light conversion layer.

[0096] The lower light conversion layer 130 in this disclosure can be a commercially available light transfer film, typically a film containing a lower light conversion agent. In this embodiment, the lower light conversion layer 130 can be a commercially available light transfer film, such as a UV light transfer film from Sewoo or Foster. The lower light conversion layer 130 can also be homemade. The dosage and formulation of the lower light conversion agent depend on the requirements for the second wavelength of light, that is, the wavelength of light that needs to be converted to visible light.

[0097] In the disclosed embodiment, the softening point of first isolation layer 120 is higher than that of cutoff layer 110 and lower light conversion layer 130. First isolation layer 120 may be made of a modified PE (polyethylene) material, an ethylene polar material, or a non-polar olefin copolymer material, which has lower fluidity at high temperatures than cutoff layer 110 and lower light conversion layer 130. First isolation layer 120 may be a highly transparent isolation layer or other film that allows for interdiffusion between the isolation cutoff agent and the light conversion agent, such as the commercially available functional film from Mingguan New Materials.

[0098] In the embodiment of the present disclosure, the light transmittance of the cutoff layer 110 is greater than 90%, the light transmittance of the first isolation layer 120 is greater than 90%, the light transmittance of the light conversion layer is greater than 90%, and the light transmittance of all layers above the light conversion layer is not less than the light transmittance of the light conversion layer. Specifically, the light transmittance of the cutoff layer 110 is ≥ the light transmittance of the light conversion layer, and the light transmittance of the first isolation layer 120 is ≥ the light transmittance of the light conversion layer. The light transmittance of the cutoff layer 110 is usually determined based on the added cutoff agent. The longer the wavelength band that needs to be cut off (the first wavelength), the more cutoff agents are in the cutoff layer 110, the more complex the formula, and the lower the transmittance. The light transmittance of the light conversion layer is usually determined based on the added light conversion agent. The longer the wavelength band that needs to be light converted (the second wavelength), the more light conversion agents are in the light conversion layer, the more complex the formula, and the lower the transmittance.

[0099] In this embodiment, the composite film is a three-layer composite film used to cut off and control light conversion. From top to bottom, the upper cutoff layer 110 is a common film with a cutoff agent, the middle layer is the first isolation layer 120, and the lower light conversion layer is a film with a lower light conversion function, namely, the lower light conversion layer 130. The three layers of the composite film are independent of each other and are combined into an integrated structure. The function of the upper cutoff film is to control the ultraviolet band exposure range, that is, to control the UV irradiance, based on the light conversion effect of the lower layer. The first isolation layer 120 is a highly transparent isolation layer. The transmittance of the first isolation layer 120 is greater than the transmittance of the lower light conversion layer 130. In a high-temperature environment, the cutoff agent and the lower light conversion agent are isolated from each other and diffused. The lower light conversion layer 130 can convert the ultraviolet short-wave band sensitive to the battery into an absorbable visible light band, thereby improving the reliability and power of the component.

[0100] The disclosed embodiments further provide a photovoltaic module comprising a cell, with the aforementioned composite film disposed on at least one surface of the cell. The lower light conversion layer 130 of the composite film is positioned adjacent to the cell, while the cutoff layer 110 is positioned distally from the cell. For single-wavelength modules, the composite film can be applied to the front surface. For double-glass modules, the composite film must be applied to both the front and back surfaces.

[0101] In this disclosure, "front" generally refers to the light-receiving side of a photovoltaic module after installation, and "back" refers to the side opposite the "front." Unless otherwise specified, "front" and "back" refer to the two opposite sides of a layer structure. "Top-to-bottom" refers to the direction from the outer surface of a photovoltaic module toward the closest solar cell.

[0102] In this technical field, since heterojunction cells use amorphous silicon thin film technology, the cells are very sensitive to ultraviolet light, and the ultraviolet attenuation is large during the reliability test of photovoltaic modules. After the above-mentioned composite adhesive film is used on the surface of the photovoltaic module, part of the ultraviolet wavelength light can be effectively cut off and part of the ultraviolet wavelength light can be converted into visible light.

[0103] The disclosed embodiments also provide a method for preparing a composite film, wherein each layer is stacked and laid sequentially and then combined into a single body. As an embodiment, each layer of the composite film can exist separately and independently. During the photovoltaic module manufacturing process, each layer of the film is laid sequentially without adding other substances. The composite film located on the surface of the photovoltaic module is obtained by combining them together. Moreover, because the isolation layer isolates the film, each layer is independent of each other (no fusion occurs). Alternatively, during the composite film manufacturing process, each layer of the film can be combined into a single-piece composite film, and then the composite film can be used.

[0104] Experiments have shown that HJT cells with conventional high-transmittance films, HJT cells with a single optical conversion film, and PERC cells with conventional high-transmittance films all have poor spectral response in the ultraviolet and red bands. However, when the three-layer composite film of this embodiment is applied to the cell surface, it effectively converts ultraviolet wavelengths into visible light.

[0105] Please refer to Figure 2. This embodiment provides a composite adhesive film, which has a structure similar to that of the first embodiment, and includes a cutoff layer 110, a first isolation layer 120, and a lower light conversion layer 230 stacked in sequence. The difference is that an upper light conversion layer 210 and a second isolation layer 220 are stacked between the first isolation layer 120 and the lower light conversion layer 230. The upper light conversion layer 210 is closer to the first isolation layer 120 than the lower light conversion layer 230. The upper light conversion layer 210 has an upward light conversion function and is used to convert infrared light into visible light. The lower light conversion layer 230 is a film with a downward light conversion function for converting ultraviolet light into visible light. The first isolation layer 120 is used to isolate the cutoff layer 110 and the upper light conversion layer 210 from fusion with each other. The second isolation layer 220 is used to isolate the upper light conversion layer 210 and the lower light conversion layer 230. The first band light cut off by the cutoff layer 110 is at least part of the sunlight except the second band light and visible light. The second band light includes the infrared band light converted by the upper light conversion layer 210 and the ultraviolet band light converted by the lower light conversion layer 230.

[0106] As an embodiment, the first band light cut off by the cutoff layer 110 is part of the ultraviolet band light and part of the infrared band light, the second band light converted by the upper light conversion layer 210 is the remaining infrared band light, and the second band light converted by the upper light conversion layer 210 is the remaining ultraviolet band light.

[0107] In the embodiment of the present disclosure, the gram weight of the composite film is ≤760g / ㎡, the gram weight of the cut-off layer 110 is ≤200g / ㎡, the gram weight of the first isolation layer 120 is ≤80g / ㎡, the gram weight of the upper light conversion layer 210 is ≤200g / ㎡, the gram weight of the second isolation layer 220 is ≤80g / ㎡, and the gram weight of the lower light conversion layer 230 is ≤200g / ㎡.

[0108] From top to bottom, the first layer of the composite film, the cut-off layer 110, is a cut-off film, which controls the spectral irradiation range according to the light conversion effect of the lower light conversion layer and the upper light conversion layer; the second layer, the first isolation layer 120, is a high-transmittance isolation layer, which needs to isolate the mutual diffusion effect of the cut-off agent and the upper light conversion agent under high temperature environment; the third layer, the upper light conversion layer 210, is a film with an upward light conversion function, which can convert the infrared light band into the visible light band; the fourth layer, the second isolation layer 220, is a high-transmittance isolation layer, which isolates the mutual diffusion effect of the upper light conversion agent of the upper light conversion layer 210 and the lower light conversion agent of the lower light conversion layer 230 under high temperature conditions; the fifth layer, the lower light conversion layer 230, is a film with a downward light conversion function, which can convert the ultraviolet light band into the visible light band; the softening points of the first isolation layer 120 and the second isolation layer 220 are higher than the softening points of the cut-off layer 110, the lower light conversion layer 230, and the upper light conversion layer 210. This technical solution can not only achieve the effect of increasing component power, but also significantly improve component reliability through cut-off control.

[0109] In this embodiment, the first cutoff layer 110 of the composite adhesive film is a conventional adhesive film containing a cutoff agent. The wavelength of the incident light is controlled by controlling the cutoff agent dosage or formulation based on the effect of the light-converting agent. This is essentially the same as the cutoff layer 110 in the first embodiment, differing in the cutoff agent dosage in the cutoff layer 110. The second layer is a highly transparent first isolation layer 120, which is the same as the first isolation layer 120 in the first embodiment. The third layer, the upper light conversion layer 210, is an adhesive film with an upward light-conversion function, converting infrared light into visible light. The fourth layer, the second isolation layer 220, is a highly transparent isolation layer, which is the same as the first isolation layer 120 in the first embodiment. The two isolation layers in this embodiment's five-layer structure are made of the same material as the first isolation layer 120 in the three-layer structure of the first embodiment. The fifth layer, the lower light conversion layer 230, is an adhesive film with a downward light-conversion function, converting short-wavelength ultraviolet light into visible light, which is the same as the lower light conversion layer 130 in the first embodiment.

[0110] In this embodiment, the five-layer structure of the composite adhesive film has a light transmittance of the first through fourth layers greater than or equal to the light transmittance of the fifth layer, the lower light conversion layer 230. Specifically, the light transmittance of the second isolation layer 220 is greater than or equal to the light transmittance of the lower light conversion layer 230, and the light transmittance of the upper light conversion layer 210 is greater than or equal to the light transmittance of the lower light conversion layer 230. The five-layer cutoff-controlled light conversion composite adhesive film in this embodiment can convert ultraviolet and infrared light into visible light.

[0111] In summary, the composite adhesive film and preparation method and photovoltaic module of the embodiments of the present disclosure can maintain a high light conversion effect for a long time, so that the module can maintain a high output power.

[0112] The foregoing description is merely an embodiment of the present disclosure and is not intended to limit the scope of protection of the present disclosure. Those skilled in the art will readily appreciate that the present disclosure may be modified and altered in various ways. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure. Industrial Applicability

[0113] The present disclosure provides a composite adhesive film, comprising a cutoff layer, a first isolation layer, and a light conversion layer stacked in sequence. The cutoff layer contains a cutoff agent for controlling the spectral irradiation range; the light conversion layer has a light conversion function for converting the ultraviolet band and / or infrared band into the visible light band; the first isolation layer is used to isolate the cutoff layer and the light conversion layer from each other. A photovoltaic module includes a cell, and the composite adhesive film is provided on at least one side of the cell surface. The lower light conversion layer of the composite adhesive film is close to the cell, and the cutoff layer is away from the cell. Photovoltaic modules encapsulated with the composite adhesive film can maintain a high light conversion effect for a long time, ensure the maximum light conversion effect, greatly improve the output power and reliability of the module, and have excellent industrial practicality.

Claims

1. A composite film, characterized in that: It includes a cutoff layer, a first isolation layer and a lower light conversion layer which are stacked in sequence. The cutoff layer contains a cutoff agent for controlling the spectral irradiation range. The lower light conversion layer has a downward light conversion function for converting the ultraviolet band into the visible light band. The first isolation layer is used to isolate the cutoff layer and the lower light conversion layer from fusing with each other under high temperature.

2. A composite film, characterized in that: It comprises a cut-off layer, a first isolation layer and a light conversion layer which are stacked in sequence. The cut-off layer contains a cut-off agent for controlling the spectral irradiation range. The light conversion layer has a light conversion function for converting ultraviolet and / or infrared bands into visible light bands. The first isolation layer is used to isolate the cut-off layer and the light conversion layer from fusing with each other under high temperature.

3. The composite adhesive film according to claim 2, characterized in that: The light conversion layer is an upper light conversion layer, which has an upper light conversion function and is used to convert the infrared band into the visible light band; Optionally, the light conversion layer has both upward light conversion and downward light conversion functions, and is used to convert ultraviolet and infrared bands into visible light bands.

4. The composite adhesive film according to any one of claims 1 to 3, characterized in that: The light transmittance of the cut-off layer is greater than or equal to the light transmittance of the lower light conversion layer, and the light transmittance of the first isolation layer is greater than or equal to the light transmittance of the lower light conversion layer; or The light transmittance of the cut-off layer is greater than or equal to the light transmittance of the light conversion layer, and the light transmittance of the first isolation layer is greater than or equal to the light transmittance of the light conversion layer.

5. The composite adhesive film according to any one of claims 1 to 4, characterized in that: The gram weight of the cut-off layer is ≤260g / ㎡, the gram weight of the first isolation layer is ≤80g / ㎡, and the gram weight of the lower light conversion layer is ≤260g / ㎡.

6. A composite adhesive film according to any one of claims 1 to 5, characterized in that: An upper light conversion layer and a second isolation layer are stacked between the first isolation layer and the lower light conversion layer. The upper light conversion layer has an upward light conversion function and is used to convert the infrared band into a visible light band. The first isolation layer is used to isolate the cutoff layer and the upper light conversion layer from merging with each other, and the second isolation layer is used to isolate the upper light conversion layer and the lower light conversion layer from merging with each other.

7. A composite adhesive film according to any one of claims 1 to 6, characterized in that: The composite adhesive film is provided with a cut-off layer, a first isolation layer, an upper light conversion layer, a second isolation layer and a lower light conversion layer in sequence; or The composite adhesive film is provided with a cut-off layer, a first isolation layer, a lower light conversion layer, a second isolation layer and an upper light conversion layer in sequence.

8. A composite adhesive film according to claim 6 or 7, characterized in that: The light transmittance of the second isolation layer is greater than or equal to the light transmittance of the lower light conversion layer, and the light transmittance of the upper light conversion layer is greater than or equal to the light transmittance of the lower light conversion layer.

9. The composite adhesive film according to any one of claims 6 to 8, characterized in that: The gram weight of the cut-off layer is ≤200g / ㎡, the gram weight of the first isolation layer and the second isolation layer is ≤80g / ㎡ respectively, and the gram weight of the lower light conversion layer and the upper light conversion layer is ≤200g / ㎡ respectively.

10. The composite adhesive film according to any one of claims 1 or 9, characterized in that: The addition amount of the cut-off agent in the cut-off layer is 0.1% to 2%.

11. The composite adhesive film according to any one of claims 6 to 10, characterized in that: The softening points of the first isolation layer and the second isolation layer are higher than the softening points of the cut-off layer, the lower light conversion layer, and the upper light conversion layer.

12. The composite adhesive film according to any one of claims 6 to 10, characterized in that: The first isolation layer and the second isolation layer are the same or different; Optionally, the isolation layer is selected from one or more of modified PE (polyethylene) materials, ethylene polar materials, and ethylene copolymer non-polar materials; Optionally, the fluidity of the isolation layer at a high temperature is lower than that of the cut-off layer, the lower light conversion layer and the upper light conversion layer.

13. The composite adhesive film according to any one of claims 1 to 12, characterized in that: The high temperature refers to a temperature above 40°C.

14. The composite adhesive film according to any one of claims 1 to 13, characterized in that: The layers of the composite adhesive film are independent of each other and are composited into an integrated structure.

15. The method for preparing the composite adhesive film according to any one of claims 1 to 14, comprising the following steps: Lay each layer in turn and combine them into one; Optionally, during the manufacturing process of the photovoltaic module, each layer is sequentially laid on the cell sheet so that the composite adhesive film is arranged on the photovoltaic module; or The above layers are used to prepare an integrated composite adhesive film.

16. A photovoltaic module, comprising a cell, characterized in that: The upper surface and / or lower surface of the cell is provided with the composite adhesive film according to any one of claims 1 to 15; the light conversion layer of the composite adhesive film is close to the cell, and the cut-off layer is far away from the cell; Optionally, the lower light conversion layer of the composite adhesive film is close to the battery cell, and the cut-off layer is far away from the battery cell.

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