A colored photovoltaic film and its preparation method

Abstract

This invention discloses a colored photovoltaic film layer and its preparation method, belonging to the field of photovoltaic cell technology. The preparation method includes the following steps: (1) ultrasonically dispersing silica nanoparticles in an organic solvent to obtain a silica dispersion; (2) coating the silica dispersion onto a clean substrate to obtain a substrate coated with a wet film; (3) placing the substrate coated with the wet film into a sealed cavity, reducing the air pressure in the sealed cavity from standard atmospheric pressure to 2 Pa to 20 Pa within 4 s to 10 s; and then increasing the air pressure in the sealed cavity to 10 Pa. 3 Pa~10 5 The pressure inside the sealed cavity is maintained at room temperature to 55°C and RH 45% to 55% for 15 to 30 minutes. Afterward, the pressure inside the sealed cavity is restored to standard atmospheric pressure, and the substrate with the colored photovoltaic film layer is removed from the sealed cavity. This preparation method can obtain a colored photovoltaic film layer with uniform thickness.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic cell technology, specifically relating to a colored photovoltaic film layer and its preparation method. Background Technology

[0002] Colored photovoltaic cells and modules are new types of photovoltaic products developed based on traditional photovoltaic technology, combined with optical design, material modification and aesthetic requirements. Their core is to achieve multi-color presentation of photovoltaic devices through technical means while ensuring photoelectric conversion performance. This breaks the "single dark color" appearance limitation of traditional photovoltaic modules and becomes a key direction for the transformation of photovoltaic technology from "functionality" to "combination of function and aesthetics". Summary of the Invention

[0003] This invention is based on the inventor's discovery and understanding of the following facts and problems: Silica is often used in color photovoltaic cells and modules, but for conventional monodisperse silica nanospheres, spin coating is usually used to coat the surface of substrates such as glass, which is only suitable for the preparation of small-area antireflection layers. Moreover, because spin coating forms a wet film on the substrate surface through centrifugal force, the thickness of the color photovoltaic film layer is uneven.

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a colored photovoltaic film layer and a method for preparing the same. The colored photovoltaic film layer prepared by this method has a uniform thickness.

[0005] In a first aspect, embodiments of the present invention provide a method for preparing a colored photovoltaic film layer, the method comprising the following steps:

[0006] (1) The silica nanoparticles were ultrasonically dispersed in an organic solvent to obtain a silica dispersion; (2) The silica dispersion is applied to a clean substrate to obtain a substrate coated with a wet film; (3) Place the substrate coated with the wet film into the sealed cavity, and reduce the air pressure in the sealed cavity from standard atmospheric pressure to 2 Pa to 20 Pa within 4 s to 10 s; then increase the air pressure in the sealed cavity to 10 Pa. 3 Pa~10 5 The pressure inside the sealed cavity is maintained at room temperature to 55°C and RH 45% to 55%, respectively, for 15 to 30 minutes. After that, the pressure inside the sealed cavity is restored to standard atmospheric pressure, and the substrate with the colored photovoltaic film layer is removed from the sealed cavity.

[0007] The advantages and technical effects of the preparation method of this invention are as follows: The preparation method of this invention involves applying a short negative pressure (4-10 seconds) to the wet film after its formation, causing the silica nanospheres to rapidly enter a "supersaturated state." Under the influence of gravity and van der Waals forces, they spontaneously and orderly align on the substrate surface, and then maintain this state for 10 seconds. 3 Pa~10 5 Under a negative pressure of Pa, and with constant humidity and temperature, a uniformly thick colored photovoltaic film layer is obtained after the solvent has completely evaporated.

[0008] In some embodiments, the median particle size Dv50 of the silica nanoparticles is 100 nm to 500 nm.

[0009] In some embodiments, the organic solvent is ethanol, or a mixture of ethanol and water, or a mixture of ethanol and isopropanol.

[0010] In some embodiments, the mass concentration of the silica dispersion is 0.3% to 3%.

[0011] In some embodiments, the substrate is ITO glass or FTO glass.

[0012] In some embodiments, the coating method is slot coating or scraping, the coating speed is 5 mm / s to 30 mm / s, and the injection speed is 1 μL to 200 μL / s.

[0013] In some embodiments, the air pressure inside the sealed cavity is reduced from standard atmospheric pressure to 4 Pa ​​to 8 Pa within 4 s to 10 s.

[0014] In some embodiments, the temperature inside the sealed cavity is maintained at 40~55°C.

[0015] In some embodiments, the temperature and humidity within the sealed cavity are maintained at 45°C and 50% RH, respectively.

[0016] Secondly, embodiments of the present invention provide a colored photovoltaic film layer, which is prepared by the preparation method described in the first aspect.

[0017] The advantages and technical effects of the colored photovoltaic film layer in this invention are as follows: Because the preparation method of this invention is used, the colored photovoltaic film layer of this invention has a uniform thickness. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating step (3) of the method for preparing the colored photovoltaic film layer of the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] In a first aspect, embodiments of the present invention provide a method for preparing a colored photovoltaic film layer, the method comprising the following steps: (1) The silica nanoparticles were ultrasonically dispersed in an organic solvent to obtain a silica dispersion; (2) The silica dispersion is applied to a clean substrate to obtain a substrate coated with a wet film; (3) such as Figure 1 As shown, the substrate coated with a wet film is placed in a sealed cavity, and the air pressure in the sealed cavity is reduced from standard atmospheric pressure to 2 Pa to 20 Pa (e.g., 2 Pa, 4 Pa, 5 Pa, 6 Pa, 8 Pa, 10 Pa, 12 Pa, 14 Pa, 16 Pa, 18 Pa, 20 Pa, etc.) within 4 s to 10 s (e.g., 4 Pa, 5 Pa, 6 Pa, 8 Pa, 10 Pa, 12 Pa, 14 Pa, 16 Pa, 18 Pa, 20 Pa, etc.); then the air pressure in the sealed cavity is increased to 10 Pa. 3 Pa~10 5 Pa (e.g., 10) 3 Pa, 10 4 Pa, 10 5 The temperature and humidity inside the sealed cavity are maintained at room temperature to 55°C (e.g., 25°C, 30°C, 35°C, 40°C, 45°C, 48°C, 50°C, 52°C, 55°C, etc.) and RH 45% to RH 55% (e.g., RH 45%, RH 48%, RH 50%, RH 52%, RH 55%, etc.) for 15 to 30 minutes (e.g., 15 minutes, 20 minutes, 25 minutes, 30 minutes, etc.). Then, the air pressure inside the sealed cavity is restored to standard atmospheric pressure, and the substrate with the colored photovoltaic film layer is removed from the sealed cavity.

[0021] The preparation method of this invention involves applying a short-term (4s~10s) negative pressure to the wet film after its formation, causing the silica nanospheres to rapidly enter a "supersaturated state." Under the influence of gravity and van der Waals forces, they spontaneously and orderly align on the substrate surface, and then maintain this state for 10 seconds. 3 Pa~10 5 Under a negative pressure of Pa, and with constant humidity and temperature, a uniformly thick colored photovoltaic film layer is obtained after the solvent has completely evaporated.

[0022] In some embodiments, the median particle size Dv50 of the silica nanoparticles is 100 nm to 500 nm, such as 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, etc. Colored photovoltaic films formed from silica nanoparticles with a median particle size Dv50 within the above range have the following significant advantages: uniform particle size distribution, high specific surface area, ease of surface functionalization, and excellent optical properties, all of which work together to improve the performance of the colored photovoltaic film.

[0023] In some embodiments, the organic solvent is ethanol, or a mixture of ethanol and water, or a mixture of ethanol and isopropanol. The organic solvents listed above contribute to the uniform dispersion of silica nanoparticles.

[0024] In some embodiments, the mass concentration of the silica dispersion is 0.3% to 3%, for example, 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, etc. When the mass concentration of the silica dispersion is within the above range, the prepared colored photovoltaic film has advantages such as good dispersibility, high solid content, and improved material mechanical properties.

[0025] In some embodiments, the substrate is glass, ITO glass, or FTO glass. ITO glass, with its high light transmittance, high conductivity, and ultra-thin profile, performs exceptionally well in colored photovoltaic modules that prioritize both high efficiency and aesthetics. FTO glass, on the other hand, is competitive in large-scale applications due to its cost-effectiveness and environmental friendliness.

[0026] In some embodiments, the coating method is slot coating or blade coating, with a coating speed of 5 mm / s to 30 mm / s, such as 5 mm / s, 10 mm / s, 15 mm / s, 20 mm / s, 25 mm / s, 30 mm / s, etc., and a liquid injection speed of 1 μL to 200 μL / s, such as 1 μL / s, 10 μL / s, 50 μL / s, 100 μL / s, 150 μL / s, 200 μL / s, etc. These coating methods help promote uniform wet film thickness.

[0027] In some embodiments, the air pressure inside the sealed cavity is reduced from standard atmospheric pressure to 4 Pa ​​to 8 Pa within 4 s to 10 s.

[0028] In some embodiments, the temperature within the sealed cavity is maintained at 40-55°C. If this temperature is too high, it is detrimental to improving the orderliness of the silica nanospheres on the substrate surface. Conversely, if the temperature is too low, the solvent evaporation time becomes excessively long.

[0029] Preferably, the temperature and humidity inside the sealed cavity are maintained at 45°C and RH50%, respectively. Meeting this condition can improve the uniformity of the thickness of the colored photovoltaic film layer and shorten the process time of step (3), thereby improving production efficiency.

[0030] Secondly, embodiments of the present invention provide a colored photovoltaic film layer, which is prepared by the preparation method described in the first aspect.

[0031] Because the preparation method of this invention is used, the colored photovoltaic film layer of this invention has a uniform thickness.

[0032] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0033] Example 1 (1) Preparation of silica dispersion: Silica nanoparticles with a median particle size Dv50 of 200 nm were ultrasonically dispersed in ethanol to obtain a silica dispersion with a mass concentration of 1%. (2) Preparation of wet film: A wet film was prepared on a clean ITO glass by slit coating at a coating speed of 8 mm / s and a liquid injection speed of 100 μL / s. (3) Preparation of colored photovoltaic film layer: Place the substrate coated with wet film into the sealed cavity, open the vacuum valve, and within 5 seconds, reduce the air pressure in the sealed cavity from standard atmospheric pressure to 5 Pa. Then, introduce air to raise the air pressure in the sealed cavity to 10 Pa. 4 Pa, maintain the temperature and humidity inside the sealed cavity at 45℃ and RH50% for 30 minutes, then introduce air into the sealed cavity to restore the air pressure inside the sealed cavity to standard atmospheric pressure, and remove the substrate with a colored photovoltaic film layer with a thickness of 1μm from the sealed cavity.

[0034] Example 2 (1) Preparation of silica dispersion: Silica nanoparticles with a median particle size Dv50 of 300 nm were ultrasonically dispersed in ethanol to obtain a silica dispersion with a mass concentration of 1%. (2) Preparation of wet film: A wet film was prepared on a clean ITO glass by slit coating at a coating speed of 8 mm / s and a liquid injection speed of 100 μL / s. (3) Preparation of colored photovoltaic film layer: Place the substrate coated with wet film into the sealed cavity, open the vacuum valve, and within 5 seconds, reduce the air pressure in the sealed cavity from standard atmospheric pressure to 5 Pa. Then, introduce air into the sealed cavity to raise the air pressure in the sealed cavity to 10 Pa. 4Pa, maintain the temperature and humidity inside the sealed cavity at 45℃ and RH50% for 30 minutes, then introduce air into the sealed cavity to restore the air pressure inside the sealed cavity to standard atmospheric pressure, and remove the substrate with a colored photovoltaic film layer with a thickness of 1μm from the sealed cavity.

[0035] Example 3 (1) Preparation of silica dispersion: Silica nanoparticles with a median particle size Dv50 of 400 nm were ultrasonically dispersed in ethanol to obtain a silica dispersion with a mass concentration of 1%. (2) Preparation of wet film: A wet film was prepared on a clean ITO glass by slit coating at a coating speed of 8 mm / s and a liquid injection speed of 100 μL / s. (3) Preparation of colored photovoltaic film layer: Place the substrate coated with wet film into the sealed cavity, open the vacuum valve, and within 5 seconds, reduce the air pressure in the sealed cavity from standard atmospheric pressure to 5 Pa. Then, introduce air into the sealed cavity to raise the air pressure in the sealed cavity to 10 Pa. 4 Pa, maintain the temperature and humidity inside the sealed cavity at 45℃ and RH50% for 30 minutes, then introduce air into the sealed cavity to restore the air pressure inside the sealed cavity to standard atmospheric pressure, and remove the substrate with a colored photovoltaic film layer with a thickness of 1μm from the sealed cavity.

[0036] Example 4 (1) Preparation of silica dispersion: Silica nanoparticles with a median particle size Dv50 of 200 nm were ultrasonically dispersed in ethanol to obtain a silica dispersion with a mass concentration of 1%. (2) Preparation of wet film: A wet film was prepared on a clean ITO glass by slit coating at a coating speed of 8 mm / s and a liquid injection speed of 100 μL / s. (3) Preparation of colored photovoltaic film layer: Place the substrate coated with wet film into the sealed cavity, open the vacuum valve, and within 5 seconds, reduce the air pressure in the sealed cavity from standard atmospheric pressure to 5 Pa. Then, introduce air into the sealed cavity to raise the air pressure in the sealed cavity to 10 Pa. 4 Pa, maintaining the temperature and humidity inside the sealed cavity at 55℃ and RH50% for 15 minutes, then introducing air into the sealed cavity to restore the air pressure inside the sealed cavity to standard atmospheric pressure, and removing the substrate with a colored photovoltaic film layer with a thickness of 1μm from the sealed cavity.

[0037] Comparative Example 1 (1) Preparation of silica dispersion: Silica nanoparticles with a median particle size Dv50 of 200 nm were ultrasonically dispersed in ethanol to obtain a silica dispersion with a mass concentration of 1%. (2) Preparation of wet film: A wet film was prepared on a clean ITO glass by slit coating at a coating speed of 8 mm / s and a liquid injection speed of 100 μL / s. (3) Preparation of colored photovoltaic film layer: Place the substrate coated with wet film into a sealed cavity, open the vacuum valve, and within 5 seconds, reduce the air pressure in the sealed cavity from the standard atmospheric pressure to 5 Pa, and then maintain it at 5 Pa (it should be noted that it is difficult to control the humidity under this air pressure). Keep the temperature in the sealed cavity at 45℃ for 10 minutes, and then introduce air into the sealed cavity to restore the air pressure in the sealed cavity to the standard atmospheric pressure. Take out the substrate with the colored photovoltaic film layer semi-finished product from the sealed cavity; then put the substrate with the colored photovoltaic film layer semi-finished product into a vacuum drying oven and heat it at 90℃ for 10 minutes to obtain the substrate with the colored photovoltaic film layer. The thickness of the colored photovoltaic film layer is 1 μm.

[0038] Comparative Example 2 (1) Preparation of silica dispersion: Silica nanoparticles with a median particle size Dv50 of 200 nm were ultrasonically dispersed in ethanol to obtain a silica dispersion with a mass concentration of 1%. (2) Preparation of wet film: A wet film was prepared on a clean ITO glass by slit coating at a coating speed of 8 mm / s and a liquid injection speed of 100 μL / s. (3) Preparation of colored photovoltaic film layer: Place the substrate coated with wet film into the sealed cavity, open the vacuum valve, and within 5 seconds, reduce the air pressure in the sealed cavity from the standard atmospheric pressure to 5 Pa, and then maintain it at 5 Pa (it should be noted that it is difficult to control the humidity under this air pressure) to keep the temperature in the sealed cavity at 45℃. After 30 minutes, introduce air into the sealed cavity to restore the air pressure in the sealed cavity to the standard atmospheric pressure. Take out the substrate with colored photovoltaic film layer from the sealed cavity. The thickness of the colored photovoltaic film layer is 1 μm.

[0039] Performance testing: The thickness of the film layer is measured at 9 evenly distributed points on the surface of the colored photovoltaic film layer. The uniformity of the film layer thickness is tested using the range method according to the following formula.

[0040]

[0041] The uniformity of the colored photovoltaic film layers prepared in Examples 1-4 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0042] Table 1. Uniformity of the colored photovoltaic film layers prepared in Examples 1-4 and Comparative Examples 1-2

[0043] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a colored photovoltaic film layer, characterized in that, The preparation method includes the following steps: (1) The silica nanoparticles were ultrasonically dispersed in an organic solvent to obtain a silica dispersion; (2) The silica dispersion is applied to a clean substrate to obtain a substrate coated with a wet film; (3) Place the substrate coated with the wet film into the sealed cavity, and reduce the air pressure in the sealed cavity from standard atmospheric pressure to 2 Pa to 20 Pa within 4 s to 10 s; then increase the air pressure in the sealed cavity to 10 Pa. 3 Pa~10 5 The pressure inside the sealed cavity is maintained at room temperature to 55°C and RH 45% to 55%, respectively, for 15 to 30 minutes. After that, the pressure inside the sealed cavity is restored to standard atmospheric pressure, and the substrate with the colored photovoltaic film layer is removed from the sealed cavity.

2. The preparation method according to claim 1, characterized in that, The median particle size Dv50 of the silicon oxide nanoparticles is 100nm~500nm.

3. The preparation method according to claim 1, characterized in that, The organic solvent is ethanol, or a mixture of ethanol and water, or a mixture of ethanol and isopropanol.

4. The preparation method according to claim 1, characterized in that, The mass concentration of the silica dispersion is 0.3% to 3%.

5. The preparation method according to claim 1, characterized in that, The substrate is ITO glass or FTO glass.

6. The preparation method according to claim 1, characterized in that, The coating method is slot coating or scraping, with a coating speed of 5 mm / s to 30 mm / s and an injection speed of 1 μL to 200 μL / s.

7. The preparation method according to claim 1, characterized in that, Within 4s to 10s, the air pressure inside the sealed cavity is reduced from standard atmospheric pressure to 4Pa to 8Pa.

8. The preparation method according to claim 1, characterized in that, Maintain the temperature inside the sealed cavity at 40~55℃.

9. The preparation method according to claim 8, characterized in that, The temperature and humidity inside the sealed cavity are maintained at 45°C and 50% RH, respectively.

10. A colored photovoltaic film layer, characterized in that, The colored photovoltaic film layer is prepared by the preparation method according to any one of claims 1 to 9.

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