Passivation light conversion adhesive film, preparation method thereof and photovoltaic cell

Abstract

The invention relates to a passivation light conversion adhesive film, a preparation method thereof and a photovoltaic cell. The passivation light conversion adhesive film comprises an adhesive film main body and a passivation layer. The material adopted by the adhesive film main body comprises a light conversion agent; a passivation layer is arranged on one side of the adhesive film main body, and a passivation material adopted by the passivation layer comprises at least one of polyether amine, Lewis base and indium tin oxide. The side, provided with the passivation layer, of the adhesive film body faces the photovoltaic cell, and the photovoltaic cell is packaged through the passivation light conversion adhesive film. Compared with a photovoltaic cell packaged by using an existing adhesive film, the photovoltaic cell provided by the invention can improve the utilization rate of solar light energy.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic cells, and particularly to a passivation and light conversion film, a preparation method thereof, and a photovoltaic cell. Background Art

[0002] For existing photovoltaic cells, such as the patent document CN112951935A, when sunlight is incident on the photovoltaic cell, due to the limitation of the light wavelength corresponding to the photovoltaic cell material itself, the solar cell can only absorb a part of the light with specific wavelengths, and the utilization efficiency of sunlight is relatively low.

[0003] Therefore, how to improve the utilization efficiency of sunlight by photovoltaic cells has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In order to improve the utilization efficiency of sunlight by photovoltaic cells, this application provides a passivation and light conversion film, a preparation method thereof, and a photovoltaic cell.

[0005] A passivation and light conversion film provided to achieve the purpose of this application includes:

[0006] A film body and a passivation layer;

[0007] The material used for the film body includes a light conversion agent;

[0008] One side of the film body is provided with a passivation layer, and the material used for the passivation layer includes at least one of polyetheramine, Lewis base, and indium tin oxide.

[0009] In a possible implementation manner, the material used for the film body further includes a resin and a crosslinking agent.

[0010] In a possible implementation manner, the material used for the film body further includes a co-crosslinking agent.

[0011] In a possible implementation manner, the crosslinking agent is a peroxide crosslinking agent, and the co-crosslinking agent includes ethylene glycol dimethacrylate.

[0012] In a possible implementation manner, the material used for the film body further includes an antioxidant.

[0013] In a possible implementation manner, the material used for the film body further includes a light stabilizer.

[0014] In a possible implementation manner, the material used for the film body further includes a silane coupling agent.

[0015] According to another aspect of this application, a preparation method of a passivation and light conversion film is provided, including the following steps:

[0016] Add the above-mentioned light conversion agent to the adhesive, and mix to obtain a film material for preparing the main body of the film.

[0017] Use the film material to prepare the main body of the film.

[0018] Use a passivation material to prepare a passivation layer on one side of the main body of the film. The passivation material includes at least one of polyetheramine, Lewis base, and indium tin oxide.

[0019] According to another aspect of the present application, a photovoltaic cell is provided, and the photovoltaic cell contains the above-mentioned passivation and light conversion film.

[0020] In the present application, the light conversion agent is used to convert the light outside the absorption spectrum range of the photovoltaic cell chip into the light within the absorption wavelength range of the chip. Therefore, the chip of the photovoltaic cell encapsulated by the passivation and light conversion film provided in the present application can not only absorb the light energy in the sunlight within its absorption range, but also absorb the light outside the absorption range after wavelength conversion, and convert it into electrical energy. Compared with the photovoltaic cell encapsulated by the existing film, the present application can effectively improve the conversion efficiency and utilization rate of the light energy in the sunlight. Description of the Drawings

[0021] Figure 1 A schematic structural diagram of the photovoltaic cell showing an embodiment of the present application;

[0022] Figure 2 A schematic structural diagram of the photovoltaic cell showing an embodiment of the present application;

[0023] Figure 3 A schematic structural diagram of the photovoltaic cell showing an embodiment of the present application.

[0024] Cell chip 100, sheet-like light absorption unit 110, passivation and light conversion film 200, film main body 210, passivation layer 220, glass sheet 300. Detailed Embodiments

[0025] The following will detail various exemplary embodiments, features, and aspects of the present application with reference to the drawings. The same reference numerals in the drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0026] It should be understood that in the description of the present invention, the meaning of "a plurality of" is two or more. In addition, for a better illustration of the present application, numerous specific details are given in the following detailed description. Those skilled in the art should understand that the present application can still be implemented without some specific details. In some instances, methods, means, elements and circuits well-known to those skilled in the art, such as the wire connection mode for the output of electric energy of the cell of a photovoltaic cell, are not described in detail so as to highlight the gist of the present application, and it should not be construed as a limitation to the present application.

[0027] According to one aspect of the present application, a passivation and light conversion film 200 is provided, which includes a film main body 210 and a passivation layer 220. The material used for the film main body 210 includes a light conversion agent; a passivation layer 220 is provided on one side of the film main body 210, and the passivation material used for the passivation layer 220 includes at least one of polyetheramine, Lewis base, organic material, inorganic material and indium tin oxide. Indium tin oxide is preferably ITO, and ITO is an N-type oxide semiconductor - indium tin oxide.

[0028] It should be noted that the passivation layer refers to a layered structure with a passivation function provided on one side of the film main body. The name of the passivation layer is only for highlighting the gist of the present application, and it should not be construed as a limitation that the passivation layer must be a whole continuous layer. The passivation layer can be a whole continuous layer, or can be multiple passivation parts distributed at intervals in the same plane. The passivation part is a layered structure with a passivation function. There are corresponding passivation parts on the surface of the cut sheet unit of the cell and at the gaps between adjacent cuts. The multiple passivation parts are adjacent and spaced apart and are arranged opposite to the multiple cells, so as to passivate the cut surface of the cell cutting unit, reduce surface defects, improve cell performance, and have the effect of cost saving.

[0029] The film main body 210 is used for encapsulating and protecting the cell 100 of the battery module. The passivation layer 220 is arranged facing the cell 100, and is used for effectively passivating the surface of the cell 100 of the photovoltaic module, reducing surface defects, and is particularly suitable for passivating and repairing the surface defects caused by the increased surface area brought by laser cutting. At the same time, the light conversion agent in the film main body 210 is used to convert the band of the incident light with poor response (low quantum efficiency) of the photovoltaic cell into the band with better response (high quantum efficiency). Therefore, the passivation and light conversion film 200 provided by the present application has both passivation and light conversion performance, and can maximize the power of the module when applied to the photovoltaic module encapsulation without changing the structure of the photovoltaic cell itself.

[0030] The passivation and light conversion film 200 provided by this application includes a film main body 210 and a passivation layer 220. One side of the film main body 210 is covered with the passivation layer 220, and the side of the film main body 210 where the passivation layer 220 is provided faces the cell 100 of the photovoltaic cell for encapsulation. Among them, the material used for the film main body 210 includes a light conversion agent, and the light conversion agent is a type of material that can convert the wavelength of light waves. The light conversion agent system contains metal ions or conjugated structures that are easily excited by light. Under the irradiation of sunlight, the electrons in the metal ions or the conjugated π electrons absorb photon energy and are excited to an unstable high-energy state. When the high-energy state transitions back to the stable ground state, energy is released in the form of photons. Because the wavelengths of the absorbed and emitted light are different, it is called a light conversion agent.

[0031] This application uses a light conversion agent to convert the light outside the absorption spectrum range of the cell 100 of the photovoltaic cell into light within the absorption wavelength range of the cell. Therefore, the cell 100 of the photovoltaic cell encapsulated by the passivation and light conversion film 200 provided by this application can not only absorb the light energy in the sunlight within its absorption range, but also absorb the light after wavelength conversion outside the absorption range. Compared with the photovoltaic cells encapsulated by the existing film, this application can alleviate the limitation of the light absorption wavelength range of the cell 100 on the light energy conversion, and effectively improve the conversion efficiency and utilization rate of the light energy in the sunlight.

[0032] The passivation and light conversion film 200 provided by this application contains specific light conversion agents and passivation agents, which can significantly improve the power of the component. The composite light conversion agent has a protective structure, can form a good cross-linked network structure with the film main body, has excellent ultraviolet stability, slows down the power attenuation and aging of the photovoltaic module after long-term ultraviolet irradiation, and thus extends the service life of the passivation and light conversion film and the photovoltaic module encapsulated by it.

[0033] In a possible implementation manner, the photovoltaic cell encapsulated by the light conversion and passivation film provided by this application is a silicon cell, and the light absorption wavelength range is 400 - 1100 nm. The light conversion agent is prepared by the following method: PrF3, ErBr3, HoF3, TmCl3, YbF3, YCl3, GeS, GaS, and CsCl are added to deionized water in proportion, heated under reflux and stirred until clarified, PVB is added, stirred until clarified, the deionized water is evaporated, and ground. It can convert the infrared rays above 1200 - 2500 nm into visible light and near-infrared light with wavelengths of 400 - 1100 nm. After encapsulation, the temperature of the cell 100 is greatly reduced, and the infrared light of 1200 - 2500 nm is also effectively utilized, and the output power of the cell 100 is greatly improved.

[0034] In a possible implementation, the light conversion agent includes an ultraviolet light conversion agent, which can convert ultraviolet light into visible light within the wavelength range absorbed by the silicon cell, thereby improving the light energy utilization rate of the photovoltaic cell. This light conversion agent is suitable for converting light with a wavelength less than 400 nm into light with a wavelength of 400 - 1100 nm. This is because the vast majority of photovoltaic devices can only effectively utilize visible light and near-infrared light in sunlight. For example, the light absorption range of silicon cells is 400 - 1100 nm. The utilization efficiency of ultraviolet light (wavelength less than 400 nm) in sunlight by photovoltaic cells is relatively low. Moreover, the presence of ultraviolet light in sunlight will also reduce the service life of photovoltaic devices, especially for heterojunction (HJT) cells, which are expected to replace cells such as PERC and TOPCon and become the third-generation solar cells. This application uses a light conversion agent to convert ultraviolet light into visible light and near-infrared light that can be absorbed and converted by the photovoltaic cell, which can improve the conversion efficiency and utilization rate of sunlight energy, improve the production efficiency of photovoltaic cells, and also reduce the ultraviolet radiation received by photovoltaic cells, having the effect of anti-ultraviolet and extending the battery life.

[0035] In a possible implementation, the preset thickness of the adhesive film main body 210 is 1 - 2 mm, and the preset thickness of the passivation layer 220 is 1.5 μm.

[0036] In a possible implementation, the light conversion agent is in powder form, and the particle size of the powdered light conversion agent is 300 - 500 nm, preferably 430 nm.

[0037] In a possible implementation, the adhesive material used for the adhesive film main body 210 further includes resin and crosslinking agent. Further, the material used for the adhesive film main body 210 further includes a co-crosslinking agent. The resin includes at least one of EVA resin, POE resin, and PMMA, the crosslinking agent is a peroxide crosslinking agent, and the co-crosslinking agent includes ethylene glycol dimethacrylate.

[0038] Furthermore, the material used for the adhesive film main body 210 further includes an antioxidant. The antioxidant includes at least one of hindered phenol antioxidants and phosphite antioxidants. In this application, a crosslinked structure is formed within the adhesive film main body 210 through resin, crosslinking agent, and co-crosslinking agent to improve the stability of the adhesive film main body 210. Powdered light conversion agents are evenly distributed in the adhesive film main body 210 for wavelength conversion of light, improving the light energy conversion and utilization rate of sunlight. And antioxidants are added to the adhesive film main body to avoid the aging of the light conversion agent caused by the reaction with oxygen free radicals released by the peroxide crosslinking agent in the crosslinked structure.

[0039] In a possible implementation, the material used for the adhesive film main body 210 further includes a light stabilizer. The light stabilizer includes 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0040] In a possible implementation, the material used for the adhesive film body 210 further includes a silane coupling agent, such as an epoxy-containing silane coupling agent.

[0041] In a possible implementation, the materials used for the film body 210 include, by mass, 60 to 80 parts of resin, preferably 75 parts; 40 to 50 parts of cross-linking agent, preferably 45 parts; 30 to 50 parts of auxiliary cross-linking agent, preferably 45 parts; 20 to 30 parts of light conversion agent, preferably 25 parts; 10 to 15 parts of antioxidant, preferably 12 parts; 4 to 8 parts of light stabilizer, preferably 5 parts; and 6 to 10 parts of silane coupling agent, preferably 8 parts.

[0042] According to another aspect of the present application, a method for preparing a passivation light conversion adhesive film is provided, comprising the following steps:

[0043] Adding a light conversion agent to the adhesive, mixing to obtain a film material for preparing the film body 210;

[0044] Using film material to prepare a film body 210;

[0045] A passivation layer 220 is formed on one side of the film body 210 .

[0046] The passivation light conversion adhesive film 200 has the characteristics of excellent passivation and repair performance of surface defects of the battery cell 100, high light stability and high light absorption and conversion efficiency, and can improve the power generation efficiency of the encapsulated photovoltaic module and extend its service life.

[0047] In addition, the passivation light conversion adhesive film 200 can significantly increase the power of the component, and at the same time has excellent UV radiation stability and a long service life. It can also reduce the power attenuation of the encapsulated photovoltaic component after long-term UV irradiation, thereby ensuring power generation efficiency.

[0048] The passivation light-conversion adhesive film 200 has good initial and post-aging passivation and light-conversion effects after lamination and packaging of photovoltaic modules, and has good light transmittance in the visible light range, thereby maximizing the power generation efficiency of the photovoltaic modules.

[0049] In a possible implementation, a passivation layer is formed on one side of the adhesive film body using a passivation material, and the passivation material includes at least one of polyetheramine, Lewis base, organic material, inorganic material and indium tin oxide. Indium tin oxide is preferably ITO. Specifically, the passivation material is coated on one side of the adhesive film body and allowed to stand at room temperature to form a film without power supply and atmosphere protection.

[0050] In a possible implementation, the adhesive and the light-converting agent are mixed evenly in a mixer in a certain proportion; the mixture is fed into a casting machine and extruded into a film body 210 by plasticization; and a passivation material is coated on one side of the film body 210 to prepare a passivation layer 220 .

[0051] Furthermore, secondary plastic extrusion is then carried out, and the passivation light conversion film 200 is made by stretching, traction, and winding. In actual operation, the operation of mixing evenly can be carried out in a mixer, and the operation of extrusion and casting into a film is carried out in a casting machine. The operation of coating a passivation material on one side of the film body 210 to form a passivation layer 220 is carried out in an automatic spraying machine.

[0052] According to another aspect of the present application, a photovoltaic cell is provided, and the photovoltaic cell contains the passivation light conversion film 200. The photovoltaic cell / module provided by the present application is encapsulated by using the above-mentioned passivation light conversion film 200, which can significantly improve the power of the module, reduce the attenuation rate of the power of the module after long-term ultraviolet irradiation, and extend the service life of the photovoltaic module.

[0053] As a clean energy source with rich resources and no need for transportation, solar energy is expected to become an alternative energy source to replace traditional fossil fuels. Therefore, the development of solar energy collection and conversion technology has gradually become the focus of attention of the country and society. Photovoltaic devices can directly convert solar energy into electrical energy, which is one of the most effective ways to utilize solar energy. Photovoltaic modules are the core part of a photovoltaic power generation system. It has become a trend to improve the output power of the modules, reduce the cost per kilowatt-hour of electricity, drive the application of new module technologies and make them mature.

[0054] Traditional full-cell module technologies use full-cell wafers for assembly. Large-area full-cell wafers have large internal currents and line resistances, which means higher internal efficiency losses, and the output power and power generation of the corresponding modules will also be greatly affected. Compared with traditional full-cell module technologies, the half-cell and interdigitated back contact (IBC) module technologies that emerged based on laser cutting technology cut the full-cell into half-cells and multi-cells, reducing the internal current and line resistance, reducing power losses, and correspondingly increasing the output power and power generation; at the same time, due to the reduction of internal losses, the working temperature of the module will also decrease, making it have a higher photoelectric conversion efficiency. Moreover, since the area of the cell wafers is reduced, the circuit design can be made more scientific, and the influence of shading, including reduced power generation and hot spots, can be reduced to a certain extent. Therefore, the half-cell and IBC module technologies have become the mainstream module technologies, and these module technologies are precisely based on laser cutting technology.

[0055] In a possible implementation manner, the cell wafer 100 of the photovoltaic cell includes two or more sheet-shaped light absorption units 110. The two or more sheet-shaped light absorption units 110 are all located in the same plane, and the two or more sheet-shaped light absorption units 110 are distributed in a mesh pattern, and a preset gap is provided between adjacent two sheet-shaped light absorption units 110. This is beneficial to reducing the internal losses of the photovoltaic cell, reducing the working temperature of the photovoltaic cell, and extending the service life of the photovoltaic cell.

[0056] Multiple sheet-like light-absorbing units 110 distributed in a network are laser-cut from a whole piece of solar cell. After cutting, they are arranged at intervals and exposed on the side. Inevitably, defects are introduced on the outer surface. If the cut surface of the solar cell is not passivated and repaired in time, it may cause high recombination of carriers on the cut surface of the solar cell, resulting in a decrease in the open-circuit voltage and conversion efficiency of the solar cell, a problem of reduced battery efficiency, and ultimately a reduction in the power of the module and the power generation of the power station. The passivation and light conversion film 200 provided in this application covers the solar cell 100 with the side provided with the passivation layer 220. After the film body 210 and the solar cell 100 are stacked, during the process of encapsulating the photovoltaic cell with an external pressure, the film body 210 and the passivation layer 220 are slightly deformed under the action of the pressure to cover and wrap the outer surface of the sheet-like light-absorbing unit 110. The passivation layer 220 passivates the surface of the sheet-like light-absorbing unit 110 wrapped by the solar cell 100, which can reduce the defects of the photovoltaic cell and ensure the power of the photovoltaic cell and the power generation of the power station.

[0057] It should be noted that the photovoltaic cell provided in this application can be a single-glass module or a double-glass module. When the photovoltaic cell is a single-glass module, the photovoltaic cell includes a glass plate 300, a passivation and light conversion film 200, and a solar cell 100 that are stacked in sequence. The side of the light conversion film provided with the passivation layer 220 faces the light-absorbing side of the solar cell 100. When the photovoltaic cell is a double-glass module, it means that the photovoltaic cell includes a glass plate 300, a layer of passivation and light conversion film 200, a solar cell 100, another layer of passivation and light conversion film 200, and another glass plate 300 that are stacked in sequence. The passivation layers 220 of the two layers of light conversion films face the two sheet-like sides of the solar cell 100 respectively.

[0058] The above has described the embodiments of this application. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technologies in the market, or to enable other ordinary skill in the art in the technical field to understand the embodiments disclosed herein.

Claims

1. A passivation light conversion film, characterized in that: include: Adhesive film body and passivation layer; The material used for the adhesive film body includes a light conversion agent; A passivation layer is disposed on one side of the adhesive film body, and a material used for the passivation layer includes at least one of polyetheramine, Lewis base, and indium tin oxide.

2. The passivation light conversion adhesive film according to claim 1, characterized in that: The materials used for the main body of the film also include resin and cross-linking agent.

3. The passivation light conversion adhesive film according to claim 2, characterized in that: The material used for the main body of the adhesive film also includes a cross-linking agent.

4. The passivation light conversion adhesive film according to claim 3, characterized in that: The crosslinking agent is a peroxide crosslinking agent, and the auxiliary crosslinking agent includes ethylene glycol dimethacrylate.

5. The passivation light conversion adhesive film according to claim 1, characterized in that: The material used for the main body of the film also includes an antioxidant.

6. The passivation light conversion adhesive film according to claim 1, characterized in that: The material used for the main body of the film also includes a light stabilizer.

7. The passivation light conversion adhesive film according to claim 1, characterized in that: The material used for the main body of the adhesive film also includes a silane coupling agent.

8. A method for preparing a passivation light conversion adhesive film, characterized in that: The following steps are involved: Adding any one of claims 1 to 7 of the light conversion agent to the adhesive, and mixing to obtain a film material for preparing the film body; Using the film material to prepare a film body; A passivation layer is prepared on one side of the adhesive film body by using a passivation material, wherein the passivation material comprises at least one of polyetheramine, Lewis base and indium tin oxide.

9. A photovoltaic cell, characterized in that: The photovoltaic cell comprises the passivation light conversion adhesive film according to any one of claims 1-7.

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