Solar cell antireflection film, preparation method and solar cell

Abstract

The invention discloses a solar cell antireflection film, a preparation method and a solar cell, and relates to the technical field of solar cell films. The solar cell antireflection film comprises a solar energy antireflection film layer, a SiO2 broadband antireflection film, a TiO2 broadband antireflection film and a SiO2-TiO2 broadband antireflection film which are formed in sequence, and the solar energy antireflection film layer is prepared from the following raw materials in parts by weight: 1-10 parts of transparent polyethylene glycol terephthalate, 1-10 parts of a silane coupling agent, 1-10 parts of a coupling agent, 1-10 parts of a coupling agent, 1-10 parts of a coupling agent and 1-10 parts of a coupling agent. The coating is prepared from 35 parts of nano sol, 35-45 parts of modified polyvinylidene fluoride resin, 20-40 parts of transparent polyimide and 10-40 parts of zinc oxide. The SiO2 broadband anti-reflection film, the TiO2 broadband anti-reflection film and the SiO2-TiO2 broadband anti-reflection film are directly added on the surface of the solar cell anti-reflection film layer, so that moisture and suspended particles in the surrounding environment are not easily adsorbed on the surface of the solar cell anti-reflection film, and the light transmittance of the solar cell anti-reflection film is relatively high.

Description

Technical Field

[0001] The invention relates to the technical field of solar cell films, and in particular to a solar cell antireflection film, a preparation method and a solar cell. Background Art

[0002] With the large-scale use of solar cells, people have a great demand for the power generation efficiency of photovoltaic solar cells. Through the existing technology, an anti-reflection film is set on the surface of the solar cell to increase the incident intensity of sunlight, thereby achieving the purpose of improving the power generation efficiency. Single-layer or double-layer films are widely used in the existing technology.

[0003] How to improve the power generation efficiency of solar cells has always been one of the research focuses in the industry. The film on the surface of solar cells can affect the power generation efficiency of solar cells. Studying the film on the surface of solar cells is also one of the research focuses. The anti-reflection film can optimize the incident angle of light, so that the battery can more effectively absorb light incident at different angles. Through the design of multi-layer films, it can be optimized for specific wavelengths of light and improve the light absorption rate within the spectral range.

[0004] In the prior art, a patent with a publication (announcement) number of CN107331712A discloses a solar cell anti-reflection film, wherein the anti-reflection film includes a silicon oxynitride film layer, a silicon nitride film layer, a titanium dioxide film layer and a silicon dioxide film layer connected in sequence on the surface of a silicon wafer of a solar cell, wherein the silicon dioxide film layer is a silicon dioxide dry gel. The anti-reflection film has an excellent anti-reflection effect, can effectively reduce the existence of light reflection, and has little effect of temperature and humidity on its overall anti-reflection effect, and is suitable for various environments. Although the refractive index is controlled within 2.16 to 2.35 in this technology, long-term use will still lead to poor energy absorption rate of the later solar cell substrate. At the same time, the thickness of the existing solar cell anti-reflection film is relatively high, mostly controlled at about 50 nanometers, and the light transmittance effect is not very good, and the efficiency is low. Therefore, a solar cell anti-reflection film, a preparation method and a solar cell are urgently needed. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a solar cell anti-reflection film, a preparation method and a solar cell, which solve the problem of poor light transmittance of the prior solar cell anti-reflection film.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a solar cell anti-reflection film, comprising a solar anti-reflection film layer, a SiO2 broadband anti-reflection film, a TiO2 broadband anti-reflection film and a SiO2-TiO2 broadband anti-reflection film formed in sequence, wherein the solar anti-reflection film layer is made of the following raw materials in parts by weight: 1-10 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 35-45 parts of modified polyvinylidene fluoride resin, 20-40 parts of transparent polyimide, and 10-40 parts of zinc oxide.

[0007] Preferably, it is made of the following raw materials in the following weight ratio: 10 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 45 parts of modified polyvinylidene fluoride resin, 40 parts of transparent polyimide, and 40 parts of zinc oxide.

[0008] Preferably, the transparent polyethylene terephthalate comprises 1 part, the nanosol comprises 35 parts, the modified polyvinylidene fluoride resin comprises 35 parts, the transparent polyimide comprises 20 parts, and the zinc oxide comprises 10 parts.

[0009] Preferably, the transparent polyethylene terephthalate comprises 15 parts, the nanosol comprises 35 parts, the modified polyvinylidene fluoride resin comprises 40 parts, the transparent polyimide comprises 40 parts, and the zinc oxide comprises 25 parts.

[0010] A solar cell comprises a solar cell substrate rear shell, a solar cell substrate, a grid film, a solar anti-reflection film layer, a SiO2 broadband anti-reflection film, a TiO2 broadband anti-reflection film and a SiO2-TiO2 broadband anti-reflection film.

[0011] A method for preparing an antireflection film for a solar cell comprises the following steps:

[0012] S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, solar cell substrate, cleaning agent;

[0013] Among them, cleaning agents include isopropyl alcohol, acetone, deionized water and alcohol;

[0014] The solar cell substrate is processed by plasma cleaning and chemical etching, and the surface of the solar cell substrate is covered with a grid film with a thickness of 3 nanometers.

[0015] Transparent polyethylene terephthalate, nanosol, modified polyvinylidene fluoride resin and transparent polyimide, the four materials are mixed, zinc oxide is added and stirred for 30 minutes to obtain a mixed solution, and the mixed solution is stored at 50 degrees Celsius for use;

[0016] S2: Coating: First, lay the grid film on the outer surface of the solar cell substrate, and drip the solution mixed in step S1 onto the solar cell substrate. The temperature during dripping is about 25 degrees. Then, the solution is evenly coated on the surface of the solar cell substrate by spin coating, and cooled. After cooling, a solution film is obtained. The thickness of the solution film is 40 nanometers, which is the solar anti-reflection film layer.

[0017] S3: Heat treatment: Place the solar anti-reflection film layer in a heat treatment device for heating, the temperature is controlled between 100-150 degrees Celsius, and the time is controlled within 6 hours;

[0018] S4: Cleaning and drying: Clean the surface of the solar anti-reflection film and place it in a dust-free environment for drying;

[0019] The outer surface of the cleaned solar anti-reflection film layer is heat-treated with a SiO2 broadband anti-reflection film, and the structure with the heat-treated SiO2 broadband anti-reflection film is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film is heat-treated with a TiO2 broadband anti-reflection film, and the structure of the SiO2 broadband anti-reflection film is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film is heat-treated with a SiO2-TiO2 broadband anti-reflection film, and the structure of the SiO2-TiO2 broadband anti-reflection film is cleaned and dried.

[0020] After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film;

[0021] After the modification is completed, the modified SiO2 broadband anti-reflection film is cleaned and dried. At this time, the solar anti-reflection film layer, the SiO2 broadband anti-reflection film, the TiO2 broadband anti-reflection film and the SiO2-TiO2 broadband anti-reflection film are arranged and combined into a solar cell anti-reflection film.

[0022] Preferably, in the heat treatment of step S3, the temperature is 100-150 degrees Celsius for the middle two hours and the temperature is gradually lowered for the last two hours to obtain a solar anti-reflection film layer.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The solar cell anti-reflection film has an average transmittance of up to 98.4% in the visible light region of the surface layer, an average transmittance of 96%-98% in the visible light and near-infrared light of the bottom layer, and a new functional anti-reflection film with a refractive index of 1.34. SiO2 broadband anti-reflection film, TiO2 broadband anti-reflection film and SiO2-TiO2 broadband anti-reflection film are directly added to the surface of the solar cell anti-reflection film layer, so that moisture and suspended particles in the surrounding environment are not easily adsorbed on the surface of the solar cell anti-reflection film, and the solar cell anti-reflection film has a high light transmittance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0026] Figure 1 This is a schematic diagram of the solar cell structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the grid membrane structure of the present invention.

[0028] In the figure: 1. SiO2-TiO2 broadband anti-reflection film; 2. TiO2 broadband anti-reflection film; 3. SiO2 broadband anti-reflection film layer; 4. Solar energy anti-reflection film layer; 5. Grid film; 6. Solar cell substrate; 7. Solar cell substrate back cover. DETAILED DESCRIPTION

[0029] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In the description of the present invention, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0033] The present invention provides a technical solution: a solar cell anti-reflection film, comprising a solar anti-reflection film layer 4, a SiO2 broadband anti-reflection film 3, a TiO2 broadband anti-reflection film 2 and a SiO2-TiO2 broadband anti-reflection film 1 formed in sequence, wherein the solar anti-reflection film layer 4 is made of the following raw materials in proportion by weight: 1-10 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 35-45 parts of modified polyvinylidene fluoride resin, 20-40 parts of transparent polyimide, and 10-40 parts of zinc oxide.

[0034] Optionally, the solar anti-reflection film layer 4 is made of the following raw materials in the following weight ratio: 10 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 45 parts of modified polyvinylidene fluoride resin, 40 parts of transparent polyimide, and 40 parts of zinc oxide.

[0035] Optionally, the solar anti-reflection film layer 4 is made of the following raw materials in the following weight ratio: 1 part of transparent polyethylene terephthalate, 35 parts of nanosol, 35 parts of modified polyvinylidene fluoride resin, 20 parts of transparent polyimide, and 10 parts of zinc oxide.

[0036] Optionally, the solar anti-reflection film layer 4 is made of the following raw materials in the following weight ratio: 15 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 40 parts of modified polyvinylidene fluoride resin and 40 parts of transparent polyimide, and 25 parts of zinc oxide.

[0037] like Figure 1 As shown, a solar cell provided by the present invention comprises a solar cell substrate back shell 7, a solar cell substrate 6, a grid film 5, a solar energy anti-reflection film layer 4, a SiO2 broadband anti-reflection film 3, a TiO2 broadband anti-reflection film 2 and a SiO2-TiO2 broadband anti-reflection film 1. The structure of the grid film 5 can be as follows Figure 2 shown.

[0038] Embodiment 1:

[0039] A method for preparing an antireflection film for a solar cell comprises the following steps:

[0040] S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, cleaning agent, solar cell substrate 6, zinc oxide, the solar cell substrate 6 needs to be cleaned on the surface to ensure the surface is clean, and it can be removed by a common cleaning agent, such as isopropyl alcohol, acetone, deionized water or alcohol. The cleaning agent can remove oil, dust and organic matter, and keep the solar cell substrate 6 clean.

[0041] The solar cell substrate 6 is processed and pre-processed by plasma cleaning and chemical etching to improve the adhesion between the anti-reflection film and the solar cell substrate 6. In order to further increase the adhesion, a layer of grid film 5 is wrapped on the surface of the solar cell substrate 6. The shape of the grid film 5 can be in various forms, such as honeycomb hexagonal shape or triangle; the thickness of the grid film 5 is 3 nanometers.

[0042] 10 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 45 parts of modified polyvinylidene fluoride resin and 40 parts of transparent polyimide are mixed, and then 40 parts of zinc oxide are added and stirred for 30 minutes to obtain a mixed solution. The mixed solution is stored at 50 degrees Celsius for use.

[0043] S2: Coating: First, lay the grid film 5 on the outer surface of the solar cell substrate 6, and drop the solution mixed in step S1 onto the solar cell substrate 6 at a dropping temperature of about 25 degrees to avoid damaging the solar cell substrate 6 due to excessive temperature. Then, evenly coat the solution on the surface of the solar cell substrate 6 by spin coating, and cool it. After cooling, a solution film is obtained, and the solution film thickness is 40 nanometers, which is the solar anti-reflection film layer 4.

[0044] S3: Heat treatment: Place the solar anti-reflection film layer 4 in a heat treatment device for heating, the temperature is controlled between 100-150 degrees Celsius, the time is controlled within 6 hours, the temperature rise should be gradual, and the heating rate should not be too fast, so as not to cause excessive stress and cracks in the solar anti-reflection film layer 4. The temperature can be raised to above 100 degrees within two hours, and 100-150 degrees Celsius treatment is performed in the middle two hours, and the temperature is gradually lowered in the last two hours to obtain a solar anti-reflection film, and then the solar anti-reflection film is subjected to subsequent steps. Heat treatment helps to eliminate stress in the solar anti-reflection film, improve its microstructure, and increase density. Through heat treatment, the refractive index and extinction coefficient of the solar anti-reflection film layer 4 can be optimized, thereby improving the anti-reflection effect. At this time, the average transmittance of visible light and near-infrared light of the solar anti-reflection film is 96%-98%, and the refractive index of the solar anti-reflection film is 1.34.

[0045] In the heat treatment equipment, the solar anti-reflection film layer 4 is not easy to cool down too quickly, and is cooled slowly within two hours.

[0046] In this step, the temperature is strictly controlled and slowly cooled to prevent the solar anti-reflection film layer 4 from breaking due to excessive temperature gradient changes, thereby ensuring the quality of the solar cell anti-reflection film. The grid film 5, the solar anti-reflection film layer 4, the SiO2 broadband anti-reflection film 3, the TiO2 broadband anti-reflection film 2 and the SiO2-TiO2 broadband anti-reflection film 1 are four layers, and the thickness of the four layers is 40 nanometers, which is thinner than the 50-nanometer solar cell film in the prior art.

[0047] S4: Cleaning and Drying: Clean the surface of the solar anti-reflection film layer 4 to remove residues or contaminants that may be generated during the heat treatment process. Usually, deionized water, alcohol or other suitable cleaning agents are used for gentle cleaning; ensure that there are no impurities on the surface of the solar anti-reflection film layer 4, and then place it in a dust-free environment for drying to ensure that no water droplets or other particles remain on the surface of the solar anti-reflection film layer 4.

[0048] The outer surface of the cleaned solar anti-reflection film layer 4 is heat-treated with a SiO2 broadband anti-reflection film 3, and the structure with the heat-treated SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film 3 is heat-treated with a TiO2 broadband anti-reflection film 2, and the structure of the SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film 2 is heat-treated with a SiO2-TiO2 broadband anti-reflection film 1, and the structure of the SiO2-TiO2 broadband anti-reflection film 1 is cleaned and dried;

[0049] After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film 3;

[0050] After the modification is completed, the modified SiO2 broadband antireflection film 3 is cleaned and dried. At this time, the solar antireflection film layer 4, the SiO2 broadband antireflection film 3, the TiO2 broadband antireflection film 2 and the SiO2-TiO2 broadband antireflection film 1 are arranged and combined to form a solar cell antireflection film.

[0051] S5: Defect detection and performance evaluation: Inspect solar cell AR coatings for defects such as cracks, holes, and uneven areas using an optical microscope or other surface analysis tools.

[0052] For solar cell anti-reflection films that have no problems with defect detection, the performance of the films is evaluated through corresponding technologies; including transmittance, refractive index, film thickness, surface roughness and adhesion, etc., to detect whether the quality of the solar cell anti-reflection films is qualified.

[0053] The detection instrument can be a spectrophotometer or an ellipsometer for testing.

[0054] S6: Final test: The solar cell substrates 6 in S1-S6 are all temporary solar cell substrates 6, which are used to facilitate the preparation of solar cell anti-reflection films. The prepared solar cell anti-reflection films are carefully transferred to the solar cell substrate 6 of the solar cell for integration, and pass the photoelectric conversion efficiency, durability and environmental stability tests.

[0055] The solar cell anti-reflection film prepared according to the above steps has an average transmittance of up to 98.4% in the visible light region of the surface layer, an average transmittance of 96%-98% in the visible light and near-infrared light of the bottom layer, and a new functional anti-reflection film with a refractive index of 1.34. SiO2 broadband anti-reflection film 3, TiO2 broadband anti-reflection film 2 and SiO2-TiO2 broadband anti-reflection film 1 are directly added to the surface of the solar cell anti-reflection film layer, so that moisture and suspended particles in the surrounding environment are not easily adsorbed on the surface of the solar cell anti-reflection film, and the light transmittance of the solar cell anti-reflection film is relatively high.

[0056] Embodiment 2:

[0057] A method for preparing an antireflection film for a solar cell comprises the following steps:

[0058] S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, cleaning agent, solar cell substrate 6, zinc oxide, the solar cell substrate 6 needs to be cleaned on the surface to ensure the surface is clean, and it can be removed by a common cleaning agent, such as isopropyl alcohol, acetone, deionized water or alcohol. The cleaning agent can remove oil, dust and organic matter, and keep the solar cell substrate 6 clean.

[0059] The surface of the solar cell substrate 6 needs to be cleaned to remove oil, dust and organic matter to ensure the surface is clean. Common cleaning agents can be used for removal. The cleaning agents can be isopropyl alcohol, acetone, and deionized water.

[0060] The solar cell substrate 6 is processed and pre-processed by plasma cleaning and chemical etching to improve the adhesion between the anti-reflection film and the solar cell substrate 6. In order to further increase the adhesion, a layer of grid film 5 is wrapped on the surface of the solar cell substrate 6. The shape of the grid film 5 can be in various forms, such as honeycomb hexagonal shape or triangle; the thickness of the grid film 5 is 3 nanometers.

[0061] 1 part of transparent polyethylene terephthalate, 35 parts of nanosol, 35 parts of modified polyvinylidene fluoride resin and 20 parts of transparent polyimide, the four materials are mixed, and then 10 parts of zinc oxide are added and stirred for 30 minutes to obtain a mixed solution. The mixed solution is stored at 50 degrees Celsius for use.

[0062] S2: Coating: First, lay the grid film 5 on the outer surface of the solar cell substrate 6, and drop the solution mixed in step S1 onto the solar cell substrate 6. The temperature during the dropwise addition is about 25 degrees to avoid damage to the solar cell substrate 6 due to high temperature. Then, the solution is evenly coated on the surface of the solar cell substrate 6 by spin coating, and cooled. After cooling, a solution film is obtained. The solution film has a thickness of 10 nanometers, which is the solar anti-reflection film layer 4.

[0063] S3: Heat treatment: Place the solar anti-reflection film layer 4 in a heat treatment device for heating, and the temperature is controlled between 100-150 degrees Celsius for 6 hours. The temperature rise should be gradual, and the heating rate should not be too fast to avoid excessive stress and cracks in the solar anti-reflection film layer 4. The temperature can be raised to above 100 degrees within two hours, and 100-150 degrees Celsius treatment is performed for the middle two hours. The temperature is gradually lowered for the last two hours to obtain a solar anti-reflection film, and then the solar anti-reflection film is subjected to subsequent steps. Heat treatment helps to eliminate the stress in the solar anti-reflection film, improve its microstructure, and increase the density. Through heat treatment, the refractive index and extinction coefficient of the solar anti-reflection film layer 4 can be optimized, thereby improving the anti-reflection effect. At this time, the average transmittance of visible light and near-infrared light of the solar anti-reflection film is 96%-98%, and the refractive index of the solar anti-reflection film is 1.34.

[0064] In the heat treatment equipment, the solar anti-reflection film layer 4 is not easy to cool down too quickly, and is cooled slowly within two hours.

[0065] In this step, the temperature is lowered strictly and slowly to prevent the solar anti-reflection film layer 4 from breaking due to excessive temperature gradient changes, thereby ensuring the quality of the solar cell anti-reflection film.

[0066] S4: Cleaning and Drying: Clean the surface of the solar anti-reflection film layer 4 to remove residues or contaminants that may be generated during the heat treatment process. Usually, deionized water, alcohol or other suitable cleaning agents are used for gentle cleaning; ensure that there are no impurities on the surface of the solar anti-reflection film layer 4, and then place it in a dust-free environment for drying to ensure that no water droplets or other particles remain on the surface of the solar anti-reflection film layer 4.

[0067] The outer surface of the cleaned solar anti-reflection film layer 4 is heat-treated with a SiO2 broadband anti-reflection film 3, and the structure with the heat-treated SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film 3 is heat-treated with a TiO2 broadband anti-reflection film 2, and the structure of the SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film 2 is heat-treated with a SiO2-TiO2 broadband anti-reflection film 1, and the structure of the SiO2-TiO2 broadband anti-reflection film 1 is cleaned and dried;

[0068] After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film 3;

[0069] After the modification is completed, the modified SiO2 broadband antireflection film 3 is cleaned and dried. At this time, the solar antireflection film layer 4, the SiO2 broadband antireflection film 3, the TiO2 broadband antireflection film 2 and the SiO2-TiO2 broadband antireflection film 1 are arranged and combined to form a solar cell antireflection film.

[0070] S5: Defect detection and performance evaluation: Inspect solar cell AR coatings for defects such as cracks, holes, and uneven areas using an optical microscope or other surface analysis tools.

[0071] For solar cell anti-reflection films that have no problems with defect detection, the performance of the films is evaluated through corresponding technologies; including transmittance, refractive index, film thickness, surface roughness and adhesion, etc., to detect whether the quality of the solar cell anti-reflection films is qualified.

[0072] The detection instrument can be a spectrophotometer or an ellipsometer for testing.

[0073] S6: Final test: The solar cell substrates 6 in S1-S6 are all temporary solar cell substrates 6, which are used to facilitate the preparation of solar cell anti-reflection films. The prepared solar cell anti-reflection films are carefully transferred to the solar cell substrate 6 of the solar cell for integration, and pass the photoelectric conversion efficiency, durability and environmental stability tests.

[0074] Embodiment three:

[0075] A method for preparing an antireflection film for a solar cell comprises the following steps:

[0076] S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, cleaning agent, solar cell substrate 6, zinc oxide, the solar cell substrate 6 needs to be cleaned on the surface to ensure the surface is clean, and it can be removed by a common cleaning agent, such as isopropyl alcohol, acetone, deionized water or alcohol. The cleaning agent can remove oil, dust and organic matter, and keep the solar cell substrate 6 clean.

[0077] The solar cell substrate 6 needs to be cleaned to remove oil, dust and organic matter. To ensure the surface is clean, it can be removed by using a common cleaning agent. The cleaning agent can be isopropyl alcohol, acetone, or deionized water.

[0078] The solar cell substrate 6 is processed and pre-processed by plasma cleaning and chemical etching to improve the adhesion between the anti-reflection film and the solar cell substrate 6; in order to further increase the adhesion, a layer of grid film 5 is wrapped on the surface of the solar cell substrate 6, and the shape of the grid film 5 can be in various forms, such as honeycomb hexagonal shape or triangle; the thickness of the grid film 5 is 3 nanometers.

[0079] 15 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 40 parts of modified polyvinylidene fluoride resin and 30 parts of transparent polyimide are mixed, and then 25 parts of zinc oxide are added and stirred for 30 minutes to obtain a mixed solution. The mixed solution is stored at 50 degrees Celsius for use.

[0080] S2: Coating: First, lay the grid film 5 on the outer surface of the solar cell substrate 6, and drop the solution mixed in step S1 onto the solar cell substrate 6. The temperature during the dropwise addition is about 25 degrees to avoid damage to the solar cell substrate 6 due to high temperature. Then, the solution is evenly coated on the surface of the solar cell substrate 6 by spin coating, and cooled. After cooling, a solution film is obtained. The solution film has a thickness of 15 nanometers, which is the solar anti-reflection film layer 4.

[0081] S3: Heat treatment: Place the solar anti-reflection film layer 4 in a heat treatment device for heating, and the temperature is controlled between 100-150 degrees Celsius for 6 hours. The temperature rise should be gradual, and the heating rate should not be too fast, so as to avoid excessive stress and cracks in the solar anti-reflection film layer 4. The temperature can be raised to above 100 degrees within two hours, and 100-150 degrees Celsius treatment is carried out in the middle two hours. The temperature is gradually lowered in the last two hours to obtain a solar anti-reflection film, and then the solar anti-reflection film is subjected to subsequent steps. Heat treatment helps to eliminate the stress in the solar anti-reflection film, improve its microstructure, and increase the density. Through heat treatment, the refractive index and extinction coefficient of the solar anti-reflection film layer 4 can be optimized, thereby improving the anti-reflection effect. At this time, the average transmittance of visible light and near-infrared light of the solar anti-reflection film is 96%-98%, and the refractive index of the solar anti-reflection film is 1.34.

[0082] In the heat treatment equipment, the solar anti-reflection film layer 4 is not easy to cool down too quickly, and is cooled slowly within two hours.

[0083] In this step, the temperature is lowered strictly and slowly to prevent the solar anti-reflection film layer 4 from breaking due to excessive temperature gradient changes, thereby ensuring the quality of the solar cell anti-reflection film.

[0084] S4: Cleaning and Drying: Clean the surface of the solar anti-reflection film layer 4 to remove residues or contaminants that may be generated during the heat treatment process. Usually, deionized water, alcohol or other suitable cleaning agents are used for gentle cleaning; ensure that there are no impurities on the surface of the solar anti-reflection film layer 4, and then place it in a dust-free environment for drying to ensure that no water droplets or other particles remain on the surface of the solar anti-reflection film layer 4.

[0085] The outer surface of the cleaned solar anti-reflection film layer 4 is heat-treated with a SiO2 broadband anti-reflection film 3, and the structure with the heat-treated SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film 3 is heat-treated with a TiO2 broadband anti-reflection film 2, and the structure of the SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film 2 is heat-treated with a SiO2-TiO2 broadband anti-reflection film 1, and the structure of the SiO2-TiO2 broadband anti-reflection film 1 is cleaned and dried;

[0086] After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film 3;

[0087] After the modification is completed, the modified SiO2 broadband antireflection film 3 is cleaned and dried. At this time, the solar antireflection film layer 4, the SiO2 broadband antireflection film 3, the TiO2 broadband antireflection film 2 and the SiO2-TiO2 broadband antireflection film 1 are arranged and combined to form a solar cell antireflection film.

[0088] S5: Defect detection and performance evaluation: Inspect solar cell AR coatings for defects such as cracks, holes, and uneven areas using an optical microscope or other surface analysis tools.

[0089] For solar cell anti-reflection films that have no problems with defect detection, the performance of the films is evaluated through corresponding technologies; including transmittance, refractive index, film thickness, surface roughness and adhesion, etc., to detect whether the quality of the solar cell anti-reflection films is qualified.

[0090] The detection instrument can be a spectrophotometer or an ellipsometer for testing.

[0091] S6: Final test: The solar cell substrates 6 in S1-S6 are all temporary solar cell substrates 6, which are used to facilitate the preparation of solar cell anti-reflection films. The prepared solar cell anti-reflection films are carefully transferred to the solar cell substrate 6 of the solar cell for integration, and pass the photoelectric conversion efficiency, durability and environmental stability tests.

[0092] Embodiment 4:

[0093] A method for preparing an antireflection film for a solar cell comprises the following steps:

[0094] S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, cleaning agent, solar cell substrate 6, zinc oxide, the solar cell substrate 6 needs to be cleaned on the surface to ensure the surface is clean, and it can be removed by a common cleaning agent, such as isopropyl alcohol, acetone, deionized water or alcohol. The cleaning agent can remove oil, dust and organic matter, and keep the solar cell substrate 6 clean.

[0095] The surface of the solar cell substrate 6 needs to be cleaned to remove oil, dust and organic matter to ensure the surface is clean. It is removed by using a common cleaning agent. Isopropyl alcohol, acetone and deionized water can be used as the cleaning agent. The solar cell substrate 6 is treated and pre-treated by plasma cleaning and chemical corrosion to improve the adhesion between the anti-reflection film and the solar cell substrate 6; in order to further increase the adhesion, a layer of grid film 5 is wrapped on the surface of the solar cell substrate 6. The shape of the grid film 5 can be in various forms, such as a honeycomb hexagonal shape or a triangle; the thickness of the grid film 5 is 3 nanometers.

[0096] 6 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 37 parts of modified polyvinylidene fluoride resin and 26 parts of transparent polyimide are mixed, and then 15 parts of zinc oxide are added and stirred for 30 minutes to obtain a mixed solution. The mixed solution is stored at 50 degrees Celsius for use.

[0097] S2: Coating: First, lay the grid film 5 on the outer surface of the solar cell substrate 6, and drop the solution mixed in step S1 onto the solar cell substrate 6. The temperature during the dropwise addition is about 25 degrees to avoid damage to the solar cell substrate 6 due to high temperature. Then, the solution is evenly coated on the surface of the solar cell substrate 6 by spin coating, and cooled. After cooling, a solution film is obtained. The solution film has a thickness of 25 nanometers and is a solar anti-reflection film.

[0098] S3: Heat treatment: Place the solar anti-reflection film layer 4 in a heat treatment device for heating, and the temperature is controlled between 100-150 degrees Celsius for 6 hours. The temperature rise should be gradual, and the heating rate should not be too fast, so as to avoid excessive stress and cracks in the solar anti-reflection film layer 4. The temperature can be raised to above 100 degrees within two hours, and 100-150 degrees Celsius treatment is carried out in the middle two hours. The temperature is gradually lowered in the last two hours to obtain a solar anti-reflection film, and then the solar anti-reflection film is subjected to subsequent steps. Heat treatment helps to eliminate the stress in the solar anti-reflection film, improve its microstructure, and increase the density. Through heat treatment, the refractive index and extinction coefficient of the solar anti-reflection film layer 4 can be optimized, thereby improving the anti-reflection effect. At this time, the average transmittance of visible light and near-infrared light of the solar anti-reflection film is 96%-98%, and the refractive index of the solar anti-reflection film is 1.34.

[0099] In the heat treatment equipment, the solar anti-reflection film layer 4 is not easy to cool down too quickly, and is cooled slowly within two hours.

[0100] In this step, the temperature is lowered strictly and slowly to prevent the solar anti-reflection film layer 4 from breaking due to excessive temperature gradient changes, thereby ensuring the quality of the solar cell anti-reflection film.

[0101] S4: Cleaning and Drying: Clean the surface of the solar anti-reflection film layer 4 to remove residues or contaminants that may be generated during the heat treatment process. Usually, deionized water, alcohol or other suitable cleaning agents are used for gentle cleaning; ensure that there are no impurities on the surface of the solar anti-reflection film layer 4, and then place it in a dust-free environment for drying to ensure that no water droplets or other particles remain on the surface of the solar anti-reflection film layer 4.

[0102] The outer surface of the cleaned solar anti-reflection film layer 4 is heat-treated with a SiO2 broadband anti-reflection film 3, and the structure with the heat-treated SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film 3 is heat-treated with a TiO2 broadband anti-reflection film 2, and the structure of the SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film 2 is heat-treated with a SiO2-TiO2 broadband anti-reflection film 1, and the structure of the SiO2-TiO2 broadband anti-reflection film 1 is cleaned and dried;

[0103] After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film 3;

[0104] After the modification is completed, the modified SiO2 broadband antireflection film 3 is cleaned and dried. At this time, the solar antireflection film layer 4, the SiO2 broadband antireflection film 3, the TiO2 broadband antireflection film 2 and the SiO2-TiO2 broadband antireflection film 1 are arranged and combined to form a solar cell antireflection film.

[0105] S5: Defect detection and performance evaluation: Inspect solar cell AR coatings for defects such as cracks, holes, and uneven areas using an optical microscope or other surface analysis tools.

[0106] For solar cell anti-reflection films that have no problems with defect detection, the performance of the films is evaluated through corresponding technologies; including transmittance, refractive index, film thickness, surface roughness and adhesion, etc., to detect whether the quality of the solar cell anti-reflection films is qualified.

[0107] The detection instrument can be a spectrophotometer or an ellipsometer for testing.

[0108] S6: Final test: The solar cell substrates 6 in S1-S6 are all temporary solar cell substrates 6, which are used to facilitate the preparation of solar cell anti-reflection films. The prepared solar cell anti-reflection films are carefully transferred to the solar cell substrate 6 of the solar cell for integration, and pass the photoelectric conversion efficiency, durability and environmental stability tests.

[0109] Embodiment five:

[0110] A method for preparing an antireflection film for a solar cell comprises the following steps:

[0111] S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, cleaning agent, solar cell substrate 6, zinc oxide, the solar cell substrate 6 needs to be cleaned on the surface to ensure the surface is clean, and it can be removed by a common cleaning agent, such as isopropyl alcohol, acetone, deionized water or alcohol. The cleaning agent can remove oil, dust and organic matter, and keep the solar cell substrate 6 clean.

[0112] The surface of the solar cell substrate 6 needs to be cleaned to remove oil, dust and organic matter to ensure the surface is clean. It is removed by using a common cleaning agent. Isopropyl alcohol, acetone and deionized water can be used as the cleaning agent. The solar cell substrate 6 is treated and pre-treated by plasma cleaning and chemical corrosion to improve the adhesion between the anti-reflection film and the solar cell substrate 6; in order to further increase the adhesion, a layer of grid film 5 is wrapped on the surface of the solar cell substrate 6. The shape of the grid film 5 can be in various forms, such as a honeycomb hexagonal shape or a triangle; the thickness of the grid film 5 is 3 nanometers.

[0113] 9 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 42 parts of modified polyvinylidene fluoride resin and 35 parts of transparent polyimide are mixed, and then 30 parts of zinc oxide are added and stirred for 30 minutes to obtain a mixed solution. The mixed solution is stored at 50 degrees Celsius for use.

[0114] S2: Coating: First, lay the grid film 5 on the outer surface of the solar cell substrate 6, and drop the solution mixed in step S1 onto the solar cell substrate 6. The temperature during the dropwise addition is about 25 degrees to avoid damage to the solar cell substrate 6 due to high temperature. Then, the solution is evenly coated on the surface of the solar cell substrate 6 by spin coating, and cooled. After cooling, a solution film is obtained. The solution film has a thickness of 35 nanometers, which is the solar anti-reflection film layer 4.

[0115] S3: Heat treatment: Place the solar anti-reflection film layer 4 in a heat treatment device for heating, and the temperature is controlled between 100-150 degrees Celsius for 6 hours. The temperature rise should be gradual, and the heating rate should not be too fast, so as to avoid excessive stress and cracks in the solar anti-reflection film layer 4. The temperature can be raised to above 100 degrees within two hours, and 100-150 degrees Celsius treatment is carried out in the middle two hours. The temperature is gradually lowered in the last two hours to obtain a solar anti-reflection film, and then the solar anti-reflection film is subjected to subsequent steps. Heat treatment helps to eliminate the stress in the solar anti-reflection film, improve its microstructure, and increase the density. Through heat treatment, the refractive index and extinction coefficient of the solar anti-reflection film layer 4 can be optimized, thereby improving the anti-reflection effect. At this time, the average transmittance of visible light and near-infrared light of the solar anti-reflection film is 96%-98%, and the refractive index of the solar anti-reflection film is 1.34.

[0116] In the heat treatment equipment, the solar anti-reflection film layer 4 is not easy to cool down too quickly, and is cooled slowly within two hours.

[0117] In this step, the temperature is lowered strictly and slowly to prevent the solar anti-reflection film layer 4 from breaking due to excessive temperature gradient changes, thereby ensuring the quality of the solar cell anti-reflection film.

[0118] S4: Cleaning and Drying: Clean the surface of the solar anti-reflection film layer 4 to remove residues or contaminants that may be generated during the heat treatment process. Usually, deionized water, alcohol or other suitable cleaning agents are used for gentle cleaning; ensure that there are no impurities on the surface of the solar anti-reflection film layer 4, and then place it in a dust-free environment for drying to ensure that no water droplets or other particles remain on the surface of the solar anti-reflection film layer 4.

[0119] The outer surface of the cleaned solar anti-reflection film layer 4 is heat-treated with a SiO2 broadband anti-reflection film 3, and the structure with the heat-treated SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film 3 is heat-treated with a TiO2 broadband anti-reflection film 2, and the structure of the SiO2 broadband anti-reflection film 3 is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film 2 is heat-treated with a SiO2-TiO2 broadband anti-reflection film 1, and the structure of the SiO2-TiO2 broadband anti-reflection film 1 is cleaned and dried;

[0120] After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film 3;

[0121] After the modification is completed, the modified SiO2 broadband antireflection film 3 is cleaned and dried. At this time, the solar antireflection film layer 4, the SiO2 broadband antireflection film 3, the TiO2 broadband antireflection film 2 and the SiO2-TiO2 broadband antireflection film 1 are arranged and combined to form a solar cell antireflection film.

[0122] S5: Defect detection and performance evaluation: Inspect solar cell AR coatings for defects such as cracks, holes, and uneven areas using an optical microscope or other surface analysis tools.

[0123] For solar cell anti-reflection films that have no problems with defect detection, the performance of the films is evaluated through corresponding technologies; including transmittance, refractive index, film thickness, surface roughness and adhesion, etc., to detect whether the quality of the solar cell anti-reflection films is qualified.

[0124] The detection instrument can be a spectrophotometer or an ellipsometer for testing.

[0125] S6: Final test: The solar cell substrates 6 in S1-S6 are all temporary solar cell substrates 6, which are used to facilitate the preparation of solar cell anti-reflection films. The prepared solar cell anti-reflection films are carefully transferred to the solar cell substrate 6 of the solar cell for integration, and pass the photoelectric conversion efficiency, durability and environmental stability tests.

[0126] Data comparison and analysis:

[0127] In the production of solar cell anti-reflection film, the precondition is to conduct experiments by changing the film thickness. By changing the film thickness, the refractive index and the transmittance of visible light and near-infrared light are stabilized. The following table is used for data comparison:

[0128]

[0129]

[0130] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A solar cell antireflection film, characterized in that: The invention comprises a solar anti-reflection film layer (4), a SiO2 broadband anti-reflection film (3), a TiO2 broadband anti-reflection film (2) and a SiO2-TiO2 broadband anti-reflection film (1) which are formed in sequence, wherein the solar anti-reflection film layer (4) is made of the following raw materials in proportion by weight: 1-10 parts of transparent polyethylene terephthalate, 35 parts of nanosol, 35-45 parts of modified polyvinylidene fluoride resin, 20-40 parts of transparent polyimide and 10-40 parts of zinc oxide.

2. The solar cell antireflection film according to claim 1, characterized in that: The invention is prepared from the following raw materials in the following weight proportions: 10 parts of transparent polyethylene terephthalate, 35 parts of nano-sol, 45 parts of modified polyvinylidene fluoride resin, 40 parts of transparent polyimide and 40 parts of zinc oxide.

3. The solar cell antireflection film according to claim 1, characterized in that: The transparent polyethylene terephthalate comprises 1 part, the nanosol comprises 35 parts, the modified polyvinylidene fluoride resin comprises 35 parts, the transparent polyimide comprises 20 parts, and the zinc oxide comprises 10 parts.

4. The solar cell antireflection film according to claim 1, characterized in that: The transparent polyethylene terephthalate comprises 15 parts, the nano-sol comprises 35 parts, the modified polyvinylidene fluoride resin comprises 40 parts, the transparent polyimide comprises 40 parts, and the zinc oxide comprises 25 parts.

5. A solar cell, characterized in that: It comprises a solar cell substrate rear shell (7), a solar solar cell substrate (6), a grid film (5), a solar anti-reflection film layer (4), a SiO2 broadband anti-reflection film (3), a TiO2 broadband anti-reflection film (2) and a SiO2-TiO2 broadband anti-reflection film (1).

6. A method for preparing an antireflection film for a solar cell according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Material preparation: transparent polyethylene terephthalate, transparent polyimide, nanosol, modified polyvinylidene fluoride resin, solar cell substrate (6), cleaning agent; Among them, cleaning agents include isopropyl alcohol, acetone, deionized water and alcohol; The solar cell substrate (6) is processed by plasma cleaning and chemical etching, and the surface of the solar cell substrate (6) is covered with a layer of mesh film (5), wherein the thickness of the mesh film (5) is 3 nanometers; Transparent polyethylene terephthalate, nanosol, modified polyvinylidene fluoride resin and transparent polyimide, the four materials are mixed, zinc oxide is added and stirred for 30 minutes to obtain a mixed solution, and the mixed solution is stored at 50 degrees Celsius for use; S2: coating: firstly, laying a grid film (5) on the outer surface of a solar cell substrate (5), dripping the solution mixed in step S1 onto the solar cell substrate (6), the temperature of which is about 25 degrees, and then evenly coating the solution on the surface of the solar cell substrate (6) by spin coating, cooling, and obtaining a solution film after cooling, the solution film having a thickness of 40 nanometers, namely, the solar anti-reflection film layer (4); S3: heat treatment: placing the solar anti-reflection film layer (4) in a heat treatment device for heating, with the temperature controlled between 100-150 degrees Celsius and the time controlled within 6 hours; S4: cleaning and drying: cleaning the surface of the solar anti-reflection film layer (4) and placing it in a dust-free environment for drying; The outer surface of the cleaned solar anti-reflection film layer (4) is heat-treated with a SiO2 broadband anti-reflection film (3), and the structure of the heat-treated SiO2 broadband anti-reflection film (3) is cleaned and dried. After drying, the surface of the SiO2 broadband anti-reflection film (3) is heat-treated with a TiO2 broadband anti-reflection film (2), and the structure of the SiO2 broadband anti-reflection film (3) is cleaned and dried. After drying, the surface of the TiO2 broadband anti-reflection film (2) is heat-treated with a SiO2-TiO2 broadband anti-reflection film (1), and the structure of the SiO2-TiO2 broadband anti-reflection film (1) is cleaned and dried. After cleaning and drying are completed, hexamethyldisilazane is used to modify the surface of the SiO2 broadband antireflection film (3); After the modification is completed, the modified SiO2 broadband anti-reflection film (3) is cleaned and dried. At this time, the solar anti-reflection film layer (4), the SiO2 broadband anti-reflection film (3), the TiO2 broadband anti-reflection film (2) and the SiO2-TiO2 broadband anti-reflection film (1) are arranged and combined to form a solar cell anti-reflection film.

7. The method for preparing an antireflection film for a solar cell according to claim 6, characterized in that: In the heat treatment of step S3, the temperature is 100-150 degrees Celsius for two hours in the middle and the temperature is gradually lowered for the last two hours to obtain a solar anti-reflection film layer (4).

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