Color-adjustable flexible photovoltaic module and preparation method, and solar cell and application

Abstract

A color-adjustable flexible photovoltaic module and a preparation method, and a solar cell and an application. The color-adjustable flexible photovoltaic module comprises a cell sheet (1), a light-receiving surface transparent adhesive film layer (3) and a front sheet (5) that are sequentially arranged on the light-receiving surface of the cell sheet (1), and a back surface transparent adhesive film layer (6) and a back sheet (7) that are sequentially arranged on the back surface of the cell sheet (1), and further comprises a first transparent thin film layer (2) and a second transparent thin film layer (4). The first transparent thin film layer (2) is arranged on the light-receiving surface of the cell sheet (1) and located between the light-receiving surface of the cell sheet (1) and the light-receiving surface transparent adhesive film layer (3). The density of the end of the first transparent thin film layer (2) close to the light-receiving surface of the cell sheet (1) is less than that of the other end of the first transparent thin film layer (2), and the density difference between the two ends is 0.2-1.8 g / cm3. The mean refractive index of the first transparent thin film layer (2) is 1.8-2.2. The second transparent thin film layer (4) is arranged between the front sheet (5) and the light-receiving surface transparent adhesive film layer (3).

Description

Color-adjustable flexible photovoltaic module and preparation method, solar cell and application thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 2023106931684, filed with the Patent Office of China on June 13, 2023, entitled “Color-adjustable flexible photovoltaic module, preparation method, solar cell and application”, the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure belongs to the technical field of color-adjustable flexible photovoltaic modules, and in particular relates to color-adjustable flexible photovoltaic modules and preparation methods, as well as solar cells and applications. Background Art

[0004] Colored photovoltaic modules are an innovative application in the photovoltaic industry. Existing technologies typically create colored photovoltaic modules by applying pigments or patterns. Alternatively, interference is created on the surface of the photovoltaic module to achieve a multi-color display. However, existing technologies have certain limitations in practical applications, primarily in the following areas:

[0005] 1) Color photovoltaic modules based on the interference principle should primarily be configured as glass modules. The heavy weight and rigidity of glass modules limit their application in building-integrated photovoltaics, transportation, and other fields. The difficulty in applying this interference principle to color flexible photovoltaic modules lies in the fact that flexible photovoltaic modules use polymer encapsulation materials. When the film layer is deposited on the surface, the gases released at high temperatures directly affect the coating effect and, in turn, the display of interference colors. Glass does not present this problem, so the existing interference principle, which is typically configured as glass modules, cannot be directly transferred to flexible photovoltaic modules.

[0006] 2) Due to the inherently dark color of silicon wafers, the color of color photovoltaic modules achieved with existing technologies is also dark and lacks saturation. This limits the aesthetics of color photovoltaic modules and fails to meet users' demands for highly aesthetic and personalized products.

[0007] 3) Existing colored flexible photovoltaic modules are primarily single-color, lacking diversity and personalization. Users are unable to choose modules with different colors and patterns based on their needs and aesthetic preferences, further limiting the market potential of colored photovoltaic modules.

[0008] 4) The manufacturing process of colored photovoltaic modules is complex and costly, which puts them at a disadvantage in market competition and makes them difficult to promote and apply on a large scale.

[0009] In order to overcome these limitations, it is necessary to study new colored flexible photovoltaic modules and their preparation methods, solar cells and their applications, and at the same time, improve the color saturation and brightness of colored photovoltaic modules to make them have better aesthetic effects.

[0010] Summary of the Invention

[0011] The purpose of the present disclosure is to overcome the defects of the existing technology of color-adjustable flexible photovoltaic components, such as dark color, low saturation and single color, and to provide a color-adjustable flexible photovoltaic component and a preparation method and a solar cell and application. The color-adjustable flexible photovoltaic component can obtain different colors with high saturation and is a color-adjustable flexible photovoltaic component.

[0012] In order to achieve the above-mentioned objectives, in a first aspect, the present disclosure provides a color-adjustable flexible photovoltaic module, comprising a cell, a light-receiving surface transparent adhesive film layer and a front plate arranged in sequence on the light-receiving side of the cell, a back transparent adhesive film layer and a back plate arranged in sequence on the back of the cell, and also comprising a first transparent film layer and a second transparent film layer, the first transparent film layer being arranged on the light-receiving surface of the cell and between the light-receiving surface of the cell and the light-receiving surface transparent adhesive film layer, the density of the first transparent film layer at one end close to the light-receiving surface of the cell being less than the density at the other end of the first transparent film layer and the density difference between the two ends is 0.2-1.8 g / cm3, optionally, 0.4-1.8 g / cm3, and the second transparent film layer being arranged between the front plate and the light-receiving surface transparent adhesive film layer.

[0013] Optionally, the average refractive index of the first transparent film layer is 1.8-2.2.

[0014] Optionally, the average density of the first transparent film layer is 2.2-7.2 g / cm 3 .

[0015] Optionally, the thickness of the first transparent film layer is 100-180 nm.

[0016] Optionally, the first transparent film layer includes a transparent conductive film layer and / or a non-conductive transparent film layer.

[0017] Optionally, the transparent conductive film layer is a doped oxide containing doping elements, the oxide in the doped oxide includes at least one of indium oxide, zinc oxide, and tin oxide, and the doping element includes at least one of tin, aluminum, fluorine, and silver.

[0018] Optionally, the first transparent thin film layer is at least one of tin-doped indium oxide, aluminum zinc oxide, fluorine-doped tin oxide, and silver-doped zinc oxide.

[0019] Optionally, the first transparent film layer is tin-doped indium oxide.

[0020] Optionally, the non-conductive transparent film layer includes at least one of silicon nitride, silicon oxide, silicon oxynitride, silicon carbide, and titanium nitride.

[0021] Optionally, when the first transparent film layer is a transparent conductive film layer, the average density is 5.5-7.2 g / cm 3 ; when the first transparent film layer is a non-conductive transparent film layer, the average density is 2.2-3.2 g / cm 3 .

[0022] Optionally, the ratio of the refractive index of the front plate to the average refractive index of the first transparent film layer is 1:1.28-1.5.

[0023] Optionally, the light-receiving surface of the cell is a textured surface.

[0024] Optionally, the thickness ratio of the front plate, the second transparent film layer, the light-receiving surface transparent adhesive film layer, and the battery cell is 1-3:0.0006-0.0025:3-8:1.

[0025] Optionally, a surface of the second transparent film layer close to the light-receiving transparent adhesive film layer has a concave-convex structure.

[0026] Optionally, the concavo-convex structure enables the overall thickness of the second transparent film layer to be between 50 nm and 500 nm.

[0027] Optionally, the second transparent film layer is at least one of titanium dioxide, zirconium dioxide, zinc aluminum oxide and niobium pentoxide.

[0028] Optionally, the refractive index ratio of the front plate and the second transparent film layer is 1:1.28-1.93.

[0029] Optionally, the refractive index of the second transparent film layer is greater than 1.8.

[0030] Optionally, the density of the second transparent film layer is between 3.8-6.9 g / cm 3 , or optionally between 3.9-6.9 g / cm 3 .

[0031] Optionally, the second transparent film layer is a single-layer transparent film layer with a refractive index greater than 2.0, or a multi-layer transparent film layer with a refractive index difference between adjacent transparent film layers, the absolute value of the refractive index difference is between 0.3 and 1, and the refractive index of each film layer in the multi-layer transparent film layer shows a non-increasing or non-decreasing change.

[0032] Optionally, the single-layer transparent film layer with a refractive index greater than 2.0 is a titanium dioxide film layer or a zirconium dioxide film layer.

[0033] Optionally, the multi-layer transparent film layer is a combination of a titanium dioxide film layer and one or more selected from a zinc aluminum oxide film layer, an indium tin oxide film layer, and a niobium pentoxide film layer.

[0034] Optionally, in the direction from the front plate to the transparent adhesive film layer on the light-receiving surface, the multilayer transparent film layer is a composite film of a titanium dioxide film layer and a zinc oxide aluminum film layer arranged in sequence, or a composite film of a titanium dioxide film layer, a zinc oxide aluminum film layer, and a titanium dioxide film layer arranged in sequence.

[0035] Optionally, when the required saturation is 50%-55%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 90%-100% of the total thickness of the second transparent film layer; when the required saturation is 40%-49%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 60%-89% of the total thickness of the second transparent film layer; when the required saturation is 35%-39%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 31%-59% of the total thickness of the second transparent film layer; when the required saturation is 25%-34%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 0%-30% of the total thickness of the second transparent film layer.

[0036] In a second aspect, the present disclosure provides a method for preparing a color-adjustable flexible photovoltaic module, the method comprising the following steps:

[0037] S1. Depositing a first transparent thin film layer on the light-receiving surface of the cell by magnetron sputtering, wherein the process of depositing by magnetron sputtering comprises: first performing a first sputtering for 3-8 minutes, and then performing a second sputtering while applying a negative bias voltage to the back of the cell; wherein the vacuum degree of the first sputtering is controlled to be lower than the vacuum degree of the second sputtering; the power of the first sputtering is ≥ the power of the second sputtering, the vacuum degree of the second sputtering is 5×10-1-5×10-2Pa, and the power of the second sputtering is 6-9kw;

[0038] S2, first depositing a second transparent thin film layer on one side of the front plate;

[0039] S3, sequentially laying a backplane, a back transparent adhesive film layer, a cell with a first transparent film layer deposited thereon, a light-receiving surface transparent adhesive film layer, and a frontplane with a second transparent film layer deposited thereon, and then laminating them, wherein the first transparent film layer is located between the light-receiving surface of the cell and the light-receiving surface transparent adhesive film layer, and the second transparent film layer is located between the frontplane and the light-receiving surface transparent adhesive film layer;

[0040] After deposition, the density of one end of the first transparent film layer close to the light-receiving surface of the cell is smaller than the density of the other end of the first transparent film layer.

[0041] Optionally, the ratio of the vacuum degree of the first sputtering to the vacuum degree of the second sputtering is 3-10:1, optionally 5-10:1, and the ratio of the power of the first sputtering to the power of the second sputtering is 1-1.8:1, optionally 1.2-1.8:1.

[0042] Optionally, the negative bias conditions include: an applied voltage of 3-8 kV and an applied frequency of 300-500 Hz.

[0043] Optionally, the process of depositing the second transparent thin film layer having the concavo-convex structure in S2 includes the step of controlling the material, thickness, and position of the required film layer according to the required color, specifically including any one of the following methods a-d:

[0044] a. Imprinting one side of the front plate with an imprinting mold having a desired concave-convex structure to obtain a front plate having a concave-convex structure; then depositing a second transparent thin film layer on the concave-convex structure side of the front plate;

[0045] b. attaching a mask material having a mask pattern to one side of the front plate, and then depositing thin film materials of different materials and thicknesses on the surface; after the deposition is completed, removing the mask material to obtain a second transparent thin film layer;

[0046] c. Depositing thin film materials of different thicknesses and materials on one side of the front plate, laser scribing different areas of the thin film material to remove a portion of the film material, and then forming desired patterns of different thicknesses and / or shapes by laser scribing to obtain a second transparent thin film layer;

[0047] d. Provide a mask plate with different spacing areas, maintain different spacing distances between the mask plate and one side of the front plate, then deposit a second transparent thin film layer within the distance, and then remove the mask plate to obtain the second transparent thin film layer.

[0048] In a third aspect, the present disclosure provides a color-adjustable flexible photovoltaic module, which is prepared by the method for preparing a color-adjustable flexible photovoltaic module according to the second aspect. The color-adjustable flexible photovoltaic module of the third aspect has the same structure as the color-adjustable flexible photovoltaic module of the first aspect.

[0049] In a fourth aspect, the present disclosure provides a solar cell comprising the color-adjustable flexible photovoltaic module according to the first aspect or the third aspect.

[0050] In a fifth aspect, the present disclosure provides application of the solar cell according to the fourth aspect in a sunshade device and / or a solar energy device.

[0051] The sunshade device disclosed in the present invention may include, for example, a sunshade device or cover installed on at least one of a recreational vehicle, a camper, a store, a vending machine, and a swimming pool.

[0052] The solar energy device disclosed herein may include, for example, a solar power generation device installed on at least one of a terrace, a balcony, a rooftop, a garden fence, a fence, a wall, a window, and a driveway outside a garage. Beneficial effects:

[0053] During the research process, the inventors of the present disclosure found that in the process of preparing solar cells, in order to improve the light absorption efficiency and the photoelectric conversion efficiency: the surface area of ​​the silicon wafer surface is increased by texturing, which increases the diffuse reflection and thus reduces the reflection, so that the solar cell can better absorb light. Increase the solar cell's ability to absorb light, thereby improving the photoelectric conversion efficiency of the solar cell. However, texturing will greatly reduce the reflection of light, so the displayed color is a dark black-blue. Although the prior art mentions ITO film in heterojunction batteries, the step coverage of the ITO film (that is, the ratio of the thickness of film layer A across the step to the thickness of film layer B at the flat) is large, that is, the film thickness of each position (such as the film layer A area in the vertical direction across the step and the film layer B area in the horizontal direction at the flat) is relatively uniformly thickened, so the velvet surface on the battery surface remains relatively intact, there will still be obvious diffuse reflection, and the reflection of blue light is still very small, so the color formed is still a darker blue.

[0054] The present disclosure utilizes the above-mentioned technical solution, particularly by providing a first transparent film layer with a suitable density difference, ranging from low to high, on the surface of the cell, in conjunction with a second transparent film layer provided on the front panel. This allows the refractive index to vary appropriately across the film layers, creating interference. This reduces the cell's absorption of blue light, resulting in a bright blue color and significantly improving the cell's brightness. The density variation facilitates matching between the film layers, improving interfacial bonding and boosting cell conversion efficiency. Furthermore, color tunability can be achieved by controlling the thickness and material of the second transparent film layer to match the first transparent film layer and other features.

[0055] In an optional solution disclosed herein, a second transparent film layer having a concave-convex structure is provided, and different colors are produced by different film thicknesses, so that the film layers of a specific structure interfere with each other to form different colors with high saturation.

[0056] In the optional scheme disclosed herein, selecting a first transparent thin film layer of a specific type and a specific thickness of 100-180nm is more conducive to forming a bright blue color, which can help reduce absorption by bulk silicon and improve battery conversion efficiency. Specifically, the non-blue light energy emitted by the first transparent thin film layer of the present invention at different film thicknesses can be absorbed by bulk silicon, such as purple when its thickness is less than 100nm. When it exceeds 180nm, the absorption of ITO will increase and the color will gradually change to green, yellow or red. When it is less than 100nm, the conductivity of the first transparent thin film layer (such as ITO) may be insufficient, and the dimming based on purple is more complicated and not conducive to interference color adjustment. When it exceeds 180nm, the absorption of the first transparent thin film layer (such as ITO) increases, and the light of the wavelength to be absorbed by the bulk silicon is reflected too much, which will greatly affect the conversion efficiency of the battery cell.

[0057] The present disclosure provides a preparation method for a flexible photovoltaic module that is conducive to forming highly saturated colors. Considering increasing the collision of sputtered ions and the same probability of ions sputtering in all directions, since the acceptance angle of step A area is small and fewer ions are received, the deposited sputtered material will be relatively small and the film will be thinner; while the acceptance angle of area B is large and more ions are received, the deposited film will be thicker, which will cause the step coverage rate to become smaller and the velvet surface to become flatter. Based on this, the present disclosure forms a first transparent thin film layer through the combination of two-step sputtering processes, which reduces the diffuse reflection of blue light and allows more blue light to be reflected, which is conducive to the formation of a bright blue color on the surface of the battery cell. Among them, first in the first sputtering, the ion collision is increased under a lower vacuum degree and (the sputtering power can be optionally increased) for a certain time, that is, the probability of collision in all directions is the same, so the single downward direction becomes less, so the step coverage is poor, it will sputter more in the area with a large acceptance angle, and less in the area with a small acceptance angle, so that the velvet surface is slightly smoother, so the density of the end film layer formed is smaller, which is beneficial to reduce the absorption of blue light by the battery cell, thereby forming a bright blue color; then in the second sputtering, due to the higher vacuum degree, the ion collision is reduced, the downward component of the velocity is straighter, and at the same time a negative bias is added to attract the ions downward, so the formed film has a higher density, better quality, and a higher refractive index, which is beneficial to multi-angle and multiple interference, and is conducive to the formation of highly saturated colors.

[0058] Moreover, since the first sputtering is carried out under a lower vacuum degree, the amount of gas released by the polymer packaging material of the flexible photovoltaic module has little effect on the lower vacuum degree, and the lower vacuum degree can still maintain a relatively stable level. The consistency of the corresponding deposited film layer will be better, so the interference principle can be used to obtain a flexible photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0060] FIG1 is a schematic structural diagram of a specific embodiment of a color-adjustable flexible photovoltaic module disclosed herein;

[0061] FIG2 is a schematic structural diagram of a specific embodiment of the front plate and the second transparent film layer disclosed in the present invention;

[0062] FIG3 is a front plate with a concave-convex structure after embossing in Example 10 of the present disclosure;

[0063] FIG4 is a front plate with a concave-convex structure after sputtering a second transparent thin film layer according to the present invention.

[0064] Explanation of Reference Numerals 1. Cell, 2. First transparent film layer, 3. Light-receiving surface transparent adhesive film layer, 4. Second transparent film layer, 401. Concavo-convex structure, 5. Front plate, 6. Back transparent adhesive film layer, 7. Back plate DETAILED DESCRIPTION

[0065] In this disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this disclosure, "plurality" means two or more, unless otherwise specifically specified.

[0066] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0067] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. Among them, the terms "optional" and "optional" all mean that they may be included or not (or may be present or not).

[0068] In a first aspect, the present disclosure provides a color-adjustable flexible photovoltaic module, comprising a cell, a light-receiving transparent adhesive film layer disposed sequentially on the light-receiving side of the cell, a front plate, a back transparent adhesive film layer disposed sequentially on the back of the cell, and a back plate, and further comprising a first transparent film layer and a second transparent film layer. The first transparent film layer is disposed on the light-receiving side of the cell and is located between the light-receiving side of the cell and the light-receiving transparent adhesive film layer, and the density of the first transparent film layer at one end near the light-receiving side of the cell is less than the density at the other end of the first transparent film layer, and the density difference between the two ends is 0.2-1.8 g / cm 3 , optional 0.4-1.8g / cm 3 The second transparent film layer is arranged between the front plate and the light-receiving surface transparent adhesive film layer.

[0069] The present disclosure uses a first transparent film layer with an appropriate density difference at both ends, which can improve the color of the solar cell from dark blue to bright blue. Combined with the refractive index difference between the second transparent film layer and the front plate and each transparent adhesive film layer, as well as the structural differences and thickness differences at different positions of the adjustable second transparent film layer, more possible interfaces are formed, which promotes color adjustment of the flexible photovoltaic module while promoting the improvement of the saturation of the flexible photovoltaic module. Under the same conditions, if the density difference at both ends of the first transparent film layer is small or the density at both ends is the same, the solar cell will still be dark blue, resulting in the flexible photovoltaic module being unable to display high-saturation colors and unable to achieve rich and colorful color adjustment. If the density difference at both ends of the first transparent film layer is too large, the low-density transparent film layer portion near the light-receiving surface of the solar cell will have too low a density, a sparse structure, an unstable structure, and poor film quality, which will directly affect the performance of the solar cell.

[0070] Optionally, the second transparent film layer has a concave-convex structure on the side closest to the light-receiving transparent adhesive film layer. In this embodiment, the present disclosure specifically adjusts the density of the first transparent film layer to match the concave-convex structure of the second transparent film layer, creating interference. This creates interference on the surface of the flexible photovoltaic module, thereby displaying different colors. Furthermore, the concave-convex structure allows the second transparent film layer to be positioned at different thicknesses, creating a three-dimensional structure with more interfaces, thereby enabling the realization of a flexible photovoltaic module with multiple color-tunable colors.

[0071] In some optional embodiments of the present disclosure, the first transparent film layer includes a transparent conductive film layer and / or a non-conductive transparent film layer. In the present disclosure, when there is an electrode on the front side of the solar cell, the first transparent film layer is a transparent conductive film layer; when there is no electrode on the front side of the solar cell, the first transparent film layer is a non-conductive transparent film layer and / or a transparent conductive film layer.

[0072] Optionally, the transparent conductive film layer is a doped oxide containing a doping element, wherein the oxide in the doped oxide includes at least one of indium oxide, zinc oxide, and tin oxide, and the doping element includes at least one of tin, aluminum, fluorine, and silver. The amounts of the doping elements disclosed herein may be determined in accordance with prior art practices, and any transparent conductive film layer made of the corresponding material can achieve the effects disclosed herein.

[0073] Optionally, the first transparent film layer is at least one of tin-doped indium oxide (ITO), aluminum zinc oxide (AZO), fluorine-doped tin oxide (FTO), and silver-doped zinc oxide (AGZO).

[0074] Optionally, the first transparent film layer is tin-doped indium oxide. In this alternative, the ITO film is more conducive to changing the color of the cell from dark black to a brighter blue. This is primarily due to the high light transmittance and high refractive index of the ITO film itself. The ITO film can change the propagation characteristics of light, causing some light waves to interfere on the film surface, thereby increasing the reflection and transmission of blue light. At the same time, the ITO film reduces the transmission of other colors of light to a certain extent, making the cell appear bright blue, which is more conducive to achieving high-saturation color in combination with the second transparent film layer.

[0075] Optionally, the non-conductive transparent film layer includes at least one of silicon nitride, silicon oxide, silicon oxynitride, silicon carbide, and titanium nitride.

[0076] Optionally, the average refractive index of the first transparent film layer is 1.8-2.2.

[0077] Optionally, the ratio of the refractive index of the front panel to the average refractive index of the first transparent film layer is 1:1.28-1.5. This optimal refractive index ratio can better adjust the first transparent film layer to reduce diffuse reflection of blue light, thereby facilitating the display of a bright blue color on the cell surface and improving the color saturation of the flexible photovoltaic module.

[0078] Optionally, the average density of the first transparent film layer is 2.2-7.2 g / cm 3 .

[0079] Optionally, when the first transparent film layer is a transparent conductive film layer, the average density is 5.5-7.2 g / cm 3 When the first transparent film layer is a non-conductive transparent film layer, the average density is 2.2-3.2 g / cm 3 .

[0080] The average refractive index of the first transparent film layer of the present disclosure is measured as follows: Average Refractive Index = d1 / d×n1+d2 / d×n2, where d=d1+d2, wherein d1 is the thickness of the first end film layer of the first transparent film layer (i.e., the film obtained by the first sputtering), d2 is the thickness of the second end film layer of the first transparent film layer (i.e., the film obtained by the second sputtering), d is the total thickness of the first transparent film layer, n1 is the refractive index of the first end film layer, and n2 is the refractive index of the second end film layer. The average density is similarly calculated, i.e., Average Density = d1 / (d1+d2)×m1+d2 / (d1+d2)×m2, where m1 is the density of the first sputtering film and m2 is the density of the second sputtering film.

[0081] Optionally, the thickness of the first transparent film layer is 100-180 nm. This option is more conducive to obtaining a bright blue color on the surface of the cell.

[0082] Optionally, the light-receiving surface of the cell is a textured surface. The present disclosure can reduce diffuse reflection of blue light caused by the textured surface, making it more conducive to displaying bright blue on the cell surface and more conducive to color adjustment and saturation of the flexible photovoltaic module.

[0083] Optionally, the thickness ratio of the front panel, second transparent film layer, light-receiving surface transparent adhesive film layer, and solar cell is 1-3:0.0006-0.0025:3-8:1. It is understood that since the second transparent film layer has a concave-convex structure and its thickness varies, the thickness at different locations within the aforementioned thickness ratio should be within the desired range. In this option, setting an appropriate thickness ratio can better adjust the interference between the various layers, facilitating the simultaneous adjustment of multiple interference colors, saturation, and brightness, enabling a more colorful display.

[0084] In the present disclosure, the thickness of the back transparent film layer and the back plate can be within the existing range, and the present disclosure has no limitation thereto. For example, the thickness ratio of the back transparent film layer, the back plate, and the battery cell is 1-6:1-3:1.

[0085] It should be pointed out that in the color-adjustable flexible photovoltaic module disclosed herein, the materials of the front panel, the light-receiving surface transparent adhesive film layer, the back transparent adhesive film layer, and the back panel can be any one of the existing corresponding materials. The front panel is a flexible front panel, such as EFTE, PVDF, etc., and its refractive index is generally about 1.4. The light-receiving surface transparent adhesive film layer can be, for example, EVA, POE, silicone, etc., and its refractive index is generally about 1.4. The back transparent adhesive film layer can be, for example, EVA, POE, silicone, etc., and its refractive index is generally about 1.4. The back panel is a flexible back panel, such as EFTE, PVDF, etc., and its refractive index is generally about 1.4. The battery cell disclosed herein refers to a battery cell with metal electrodes.

[0086] Optionally, the concavo-convex structure creates a concavo-convex structure throughout the second transparent film layer, with interface differences present at different locations. The overall thickness of the second transparent film layer is between 50 and 500 nm. In this alternative, the provision of a suitably thin second transparent film layer can adjust the interference of light to form different wavelengths reflected onto the surface of the flexible photovoltaic module, further facilitating the realization of a color-tunable flexible photovoltaic module capable of simultaneously displaying multiple, highly saturated, vibrant colors.

[0087] Optionally, the refractive index ratio of the front plate and the second transparent film layer is 1:1.28-1.93. Under this optional solution, setting an appropriate refractive index ratio can have a larger refractive index difference range, which is more conducive to generating interference and coloring on the surface of the flexible photovoltaic module.

[0088] Optionally, the refractive index of the second transparent film layer is greater than 1.8. In this solution, the difference in refractive index between the second transparent film layer and the front layer is suitably large, which is conducive to generating interference and coloring on the surface of the flexible photovoltaic module.

[0089] Optionally, the density of the second transparent film layer is 3.8-6.9 g / cm 3 , optional 3.9-6.9g / cm 3 Providing a second transparent film layer with an appropriate density can adjust the suede structure on the surface of the cell to reduce diffuse reflection using a lower density film layer, while achieving a high refractive index using a high density second transparent film layer, which is more conducive to displaying a distinct blue color on the cell surface.

[0090] Optionally, the second transparent film layer is at least one of titanium dioxide, zirconium dioxide, zinc aluminum oxide and niobium pentoxide. The second transparent film layer of the present disclosure can be a single component or multiple components. When there are multiple components, each component can be stacked in a direction perpendicular to the surface of the front plate, or can be arranged in sequence in a direction parallel to the surface of the front plate. A single component or different components can also be used at different heights in the direction parallel to the surface of the front plate (as shown in Figure 2, the second transparent film layer 4 includes a two-layer structure, the first layer height close to the surface of the front plate 5 is a single component, and the second layer height upwards is a plurality of different components arranged in sequence to form a concave-convex structure 401). The refractive index and density of each film layer in the second transparent film layer of the present disclosure are determined according to the deposition method and conditions, film thickness, and substrate, and can be adjusted to obtain the required refractive index and density as needed. The refractive index of the titanium dioxide film disclosed in the present disclosure can be 1.8-2.7, and the density is 3.9-4.25g / cm 3 The refractive index of zirconium dioxide film is 2.0-2.2, and the density is 5.6-6.0g / cm 3 The refractive index of zinc oxide aluminum film is 1.8-2.2, and the density is 5.3-6.9g / cm 3 The density of Nb2O5 film is about 4.6-4.9g / cm 3 , the refractive index is between 1.9 and 2.4 at a wavelength of 550nm.

[0091] Optionally, the second transparent film layer is a single-layer transparent film layer with a refractive index greater than 2.0, or a multi-layer transparent film layer with a refractive index difference between adjacent transparent film layers, the absolute value of the refractive index difference is between 0.3 and 1, and the refractive index of each film layer in the multi-layer transparent film layer presents a non-increasing or non-decreasing change. Under this optional solution, the multi-layer transparent film layer is provided with a second transparent film layer whose refractive index changes with a certain difference and presents a non-increasing or non-decreasing change, which can better form interference on the surface of the component and is more conducive to the display of multiple colors. Among them, the non-increasing or non-decreasing change of the refractive index of the multi-layer transparent film layer means that it cannot change continuously in an increasing or decreasing manner, and requires alternating changes such as high / low / high or low / high / low. Increasing or decreasing changes do not produce interference.

[0092] The second transparent film layer disclosed herein can utilize different structures and materials depending on the specific location requirements and application scenarios. For example, the second transparent film layer disclosed herein can be made of at least one of titanium dioxide (TiO2), aluminum zinc oxide (AZO), and tin-doped indium oxide (ITO). These film materials have high refractive index, good conductivity, and transparency, contributing to the creation of rich color effects.

[0093] Optionally, the single-layer transparent film layer with a refractive index greater than 2.0 is a titanium dioxide film layer or a zirconium dioxide film layer.

[0094] Optionally, the multi-layer transparent film is a combination of a titanium dioxide film and one or more selected from zinc-aluminum oxide, indium-tin oxide, and niobium pentoxide. Specifically, in addition to the titanium dioxide film, one or more selected from zinc-aluminum oxide, indium-tin oxide, and niobium pentoxide are further provided. It should be noted that the same film can be provided as a single layer or multiple layers in different locations, such as a sandwich of titanium dioxide, zinc-aluminum oxide, and titanium dioxide layers.

[0095] Furthermore, in the direction from the front plate to the light-receiving transparent adhesive film layer, the multi-layer transparent film layer is a combination of a titanium dioxide film layer and a zinc-aluminum oxide film layer, or a combination of a titanium dioxide film layer, a zinc-aluminum oxide film layer, and a titanium dioxide film layer. Compared to a two-layer combination film, the latter three-layer combination film can increase the thickness of each film layer, which is more conducive to the production of a wider range of color rendering.

[0096] Optionally, when the desired saturation is 50%-55%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 90%-100% of the total thickness of the second transparent film layer; when the desired saturation is 40%-49%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 60%-89% of the total thickness of the second transparent film layer; when the desired saturation is 35%-39%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 31%-59% of the total thickness of the second transparent film layer; when the desired saturation is 25%-34%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 0%-30% of the total thickness of the second transparent film layer. It can be understood that the thickness of the titanium dioxide film layer refers to the total thickness of the titanium dioxide film layer. Under the optional scheme disclosed in the present invention, the TiO2 thickness ratio is appropriate, and the color saturation can be adjusted according to different needs, and the color vividness can be easily adjusted under the condition of obtaining the desired color system.

[0097] In a second aspect, the present disclosure provides a method for preparing a color-adjustable flexible photovoltaic module, wherein the color-adjustable flexible photovoltaic module is the color-adjustable flexible photovoltaic module described in the first aspect.

[0098] The preparation method is as follows:

[0099] S1, depositing a first transparent thin film layer on the light-receiving surface of the cell by magnetron sputtering;

[0100] S2, first depositing a second transparent thin film layer on one side of the front plate;

[0101] S3. Lay the back plate, the back transparent film layer, the battery cell with the first transparent film layer deposited, the light-receiving surface transparent film layer, and the front plate with the second transparent film layer deposited in sequence, and then laminate them, wherein the first transparent film layer is located between the light-receiving surface of the battery cell and the light-receiving surface transparent film layer, and the second transparent film layer is located between the front plate and the light-receiving surface transparent film layer.

[0102] After deposition, the density of one end of the first transparent film layer close to the light-receiving surface of the cell is smaller than the density of the other end of the first transparent film layer.

[0103] In S1 of the present disclosure, the process of magnetron sputtering deposition includes: first performing a first sputtering for 3-8 minutes, and then performing a second sputtering while applying a negative bias voltage to the back of the cell; wherein the vacuum degree of the first sputtering is controlled to be lower than the vacuum degree of the second sputtering; the power of the first sputtering is greater than the power of the second sputtering, and the vacuum degree of the second sputtering is 5×10 －1 -5×10 －2 Pa, the power of the second sputtering is 6-9kw.

[0104] The first sputtering process of the present disclosure employs a specific and appropriate time range as described above, significantly reducing diffuse reflection of blue light and facilitating a bright blue color on the cell surface. However, if the first sputtering time is too long under the same conditions, more velvet pits will be covered, resulting in a flat velvet structure and poor density and quality of the deposited film. If the time is too short, fewer velvet pits will be covered, and the velvet filling effect will be insufficient to reduce diffuse reflection of blue light, resulting in less blue light reflection and a darker blue brightness on the cell surface.

[0105] The second sputtering time of the present invention can be determined according to the difference between the required total thickness and the thickness of the first sputtering, and then the time range is controlled according to the deposition rate. For example, the second sputtering time can be about 8-18 minutes.

[0106] Other conditions in the magnetron sputtering deposition disclosed herein are carried out in accordance with the conditions of conventional methods. For example, the target material is ITO, the sputtering voltage can be 200-300 V, and a mixed gas of oxygen and argon is introduced with an oxygen content of 1-5% by volume.

[0107] Optionally, the ratio of the vacuum degree of the first sputtering to the vacuum degree of the second sputtering is 3-10:1, or optionally 5-10:1, and the ratio of the power of the first sputtering to the power of the second sputtering is 1-1.8:1, or optionally 1.2-1.8:1. Under this optional solution, setting a suitable large first sputtering condition can increase the number of sputtered ions and further increase the number of collisions between sputtered ions, thereby causing more sputtered ions to deposit in the contact angle area, thereby reducing the surface roughness of the battery surface, making it smoother and more conducive to reducing diffuse reflection of blue light.

[0108] Optionally, the negative bias conditions include: an applied voltage of 3-8 kW and an applied frequency of 300-500 Hz. Under this option, setting an appropriate negative bias condition can better attract sputtered ions vertically downward, which is more conducive to the formation of high-density, high-quality, and high-refractive-index films.

[0109] Optionally, in S2, the front panel may be a panel with good transparency, weather resistance and flexibility, so as to achieve long-term stability and flexible application of the color-adjustable flexible photovoltaic module.

[0110] In the present disclosure, the second transparent thin film layer can be deposited, for example, by conventional deposition methods such as magnetron sputtering, chemical vapor deposition, or solution processing, in conjunction with masking, etching, and other techniques to set different film thicknesses or film layer materials at different locations to obtain a second transparent thin film layer with or without a concave-convex structure, thereby forming a multi-color pattern. During the deposition process, the film thickness and refractive index can be controlled by adjusting deposition parameters (such as deposition rate and temperature). When the film thickness and refractive index are determined, those skilled in the art can select the corresponding deposition parameters using existing techniques. This is existing technology and does not require creative work, so it will not be repeated here.

[0111] The process of depositing the second transparent thin film layer with a concave-convex structure described in S2 can control the material, thickness, and position of the required film layer according to the required color, so that the film layer structure or thickness at different positions is different, so that it displays different colors at different positions, thereby realizing the simultaneous display of multiple colors.

[0112] Optionally, the process of depositing the second transparent film layer having a concave-convex structure described in S2 includes: a. embossing one side of the front plate with an embossing mold having the desired concave-convex structure to obtain a front plate having a concave-convex structure; and then depositing a second transparent film layer on the concave-convex structure side of the front plate (deposition is performed by methods such as magnetron sputtering, chemical vapor deposition or solution treatment). In this scheme, by embossing a multi-level concave-convex structure on the front plate, a concave-convex structure of different depths and shapes is formed. When the second transparent film layer is deposited on the surface of such a front plate, the film thickness will change due to the presence of the concave-convex structure. This change in film thickness causes interference on the surface, thereby realizing a three-dimensional color pattern. At the same time, by combining embossing marks of different depths, a richer three-dimensional color effect can be achieved on the same solar cell. This scheme realizes a three-dimensional color pattern effect of a color-adjustable flexible photovoltaic module by performing multi-level embossing on the front plate and combining different embossing marks. This method not only enhances the aesthetics of the component, but also improves its personalized characteristics. At the same time, the preparation process is simple, easy to implement, and has good practical value. It also includes the following specific advantages:

[0113] Aesthetics: Through multi-level embossing and combining different embossing marks, rich three-dimensional color patterns can be achieved, improving the visual effect of color photovoltaic modules and meeting consumers' demand for aesthetics;

[0114] Personalization: Multi-level embossing and embossing marks of different shapes can form unique color patterns, providing users with more personalized choices and increasing the added value of the product;

[0115] Simple and easy: The preparation process of this technical solution is simple, does not require complicated equipment and operations, and is easy to promote and apply in engineering;

[0116] Wide range of applications: Flexible photovoltaic modules with adjustable three-dimensional colors can be configured into building-integrated photovoltaics, household photovoltaic systems, mobile energy equipment and other fields, and have broad market prospects.

[0117] In the first optional embodiment of the present disclosure, the embossing conditions include heating and applying pressure, as long as the embossing can achieve a front plate having a concave-convex structure. For example, the embossing conditions include: a heating temperature of 80-120°C and an applied pressure of 25 Pa-105 Pa. The heating time depends on the embossing depth.

[0118] In a second optional embodiment of the present disclosure, the process of depositing a second transparent thin film layer having a concave-convex structure described in S2 includes: b. attaching a mask material having a mask pattern to one surface of the front plate, and then depositing thin film materials of different materials and thicknesses on the surface; after the deposition is completed, removing the mask material to obtain the second transparent thin film layer. In this solution, multiple film layer structures of the second transparent thin film layer can be achieved through multiple masking. Specifically, a multiple masking process can be used to form second transparent thin film layers with different film layer structures and thicknesses on the front plate; after each masking, the desired film layer can be formed in the mask-covered area by etching, sputtering, or other methods, which is more conducive to the production of second transparent thin film layers with multiple different film layer structures and thicknesses.

[0119] The second type mentioned above in the present disclosure can be optionally made of materials such as photoresist and metal film, so as to have good shielding performance and precise pattern shape. It should be pointed out that the set mask pattern is made on the mask material by photolithography, electron beam etching and other methods, and it is necessary to ensure that the accuracy and edge clarity of the mask pattern meet the preparation requirements. When the mask material with the mask pattern is attached to the front plate, it is necessary to ensure that there are no bubbles and contaminants between the mask material and the front plate to ensure a good shielding effect; it is also necessary to ensure that the deposited second transparent film layer and the front plate are not damaged in the process of removing the mask material. During the deposition process, the area of ​​the mask material shielding part is not deposited, and the original film thickness in the shielding part is not affected, forming a different film layer structure and thickness from the area without the mask material. Of course, during the preparation, those skilled in the art can check the color effect and pattern of the obtained second transparent film layer, and optimize the preparation parameters according to the test results to achieve better color effect and pattern quality.

[0120] In the third optional embodiment of the present disclosure, the process of depositing the second transparent film layer with a concave-convex structure described in S2 includes: c. depositing thin film materials of different thicknesses and different materials on one side of the front plate, laser scribing different areas of the thin film material to remove part of the thickness of the thin film material, and then forming the required patterns of different thicknesses and / or different shapes by laser scribing to obtain a second transparent film layer. In this solution, laser scribing achieves a variety of colors and patterns. Using laser scribing technology, it is possible to accurately remove part of the thickness of the thin film material on the transparent film, thereby forming different second transparent film layers in different areas. Laser scribing can engrave complex pattern shapes and achieve color patterns of multiple colors. Through laser scribing technology, complex pattern shapes such as text, graphics, gradient colors, etc. can be achieved. In this way, the color-adjustable flexible photovoltaic module can not only present a variety of colors, but also display unique color patterns according to design requirements, thereby enhancing the beauty and uniqueness of the product. Laser scribing can achieve high-precision, high-resolution thin film scribing. By adjusting the laser energy and scribing parameters, the thickness of the second transparent film layer can be varied in different areas. This results in varying degrees of light interference in these areas, thus achieving a variety of color effects. Those skilled in the art can select laser scribing conditions based on the desired thickness of the second transparent film layer. This is prior art in the field and does not require inventive effort, so it will not be further elaborated here.

[0121] The second and third technical solutions disclosed herein enable the display of different colors on a single cell, resulting in a color-adjustable flexible photovoltaic module with high color saturation and brightness, satisfying user needs for aesthetics and personalization. Furthermore, the color-adjustable flexible photovoltaic module disclosed herein is particularly well-suited for deployment in building-integrated photovoltaic applications, transportation, and other fields.

[0122] In the fourth optional embodiment of the present disclosure, the process of depositing the second transparent thin film layer having a concave-convex structure described in S2 includes: d, providing a mask plate with different spacing areas, maintaining unequal spacing distances between the mask plate and one side of the front plate in different areas, and then depositing (such as by magnetron sputtering, chemical vapor deposition or solution treatment) the second transparent thin film layer within the distance, and then removing the mask plate to obtain the second transparent thin film layer. In this scheme, by setting the mask plate and the front plate to be plated to maintain unequal spacing distances in different areas, the thickness of the film layer can be changed during the deposition process, thereby generating interference on the surface of the color-adjustable flexible photovoltaic module to achieve a glare effect. The change in spacing will affect the morphology and thickness distribution of the deposited film, which will lead to differences in color and glossiness in different areas, forming a unique glare effect, thereby realizing a flexible photovoltaic module with adjustable glare color. This scheme has high flexibility, and the spacing distribution can be adjusted according to actual needs to achieve different degrees of glare effects.

[0123] In the fourth optional embodiment of the present disclosure, the spacing distribution on the mask plate is designed based on the desired glare effect to form regions with different spacing. Variation in spacing can be achieved by adjusting the support structure between the mask plate and the front plate. When the mask plate is removed, a second transparent film layer of varying thickness is formed on the front plate, creating a glare effect.

[0124] The lamination described in S3 of the present disclosure may be, for example, heat pressing or other bonding processes, which are prior art in the art and will not be described in detail herein. The lamination steps described in S3 of the present disclosure include: first laminating the light-receiving surface of the cell with the light-receiving surface transparent adhesive film layer and the front plate on which the second transparent film layer is deposited, and then laminating the back plate, the back transparent adhesive film layer, and the back of the cell.

[0125] In a third aspect, the present disclosure provides a color-adjustable flexible photovoltaic module, which is prepared by the method for preparing a color-adjustable flexible photovoltaic module according to the second aspect. The color-adjustable flexible photovoltaic module of the third aspect has the same structure as the color-adjustable flexible photovoltaic module of the first aspect.

[0126] In a fourth aspect, the present disclosure provides a solar cell comprising the color-adjustable flexible photovoltaic module according to the first aspect or the third aspect.

[0127] In a fifth aspect, the present disclosure provides an application of the solar cell of the fourth aspect in a sunshade device and / or a solar device. The solar cell of the present disclosure can be configured in any scenario requiring a solar cell.

[0128] The sunshade device disclosed in the present invention may include, for example, a sunshade device or cover installed on at least one of a recreational vehicle, a camper, a store, a vending machine, and a swimming pool.

[0129] The solar energy device disclosed herein may include, for example, a solar power generation device installed on at least one of a terrace, a balcony, a rooftop, a garden fence, a fence, a wall, a window, and a driveway outside a garage.

[0130] The following describes embodiments of the present disclosure in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only configured to explain the present disclosure and are not to be construed as limiting the present disclosure.

[0131] Example 1

[0132] A color-adjustable flexible photovoltaic module, as shown in FIG1 , includes a cell 1 with a velvet surface on the light-receiving surface, a first transparent film layer 2 (conductive film layer, ITO) arranged on the light-receiving surface of the cell 1, a light-receiving transparent adhesive film layer 3 (EVA material) and a front plate 5 (EFTE material) arranged in sequence on one side of the light-receiving surface of the cell 1, a second transparent film layer 4 arranged on the front plate 5 and between the front plate 5 and the light-receiving transparent adhesive film layer 3, a back transparent adhesive film layer 6 (EVA material) and a back plate 7 (EFTE material) arranged in sequence on the back of the cell 1. The density of the first transparent film layer 2 at one end close to the light-receiving surface of the cell 1 is less than the density at the other end, and the density difference between the two ends of the first transparent film layer 2 is 0.4 g / cm 3 、The average density is 7.00g / cm 3 The refractive index of the front plate 5 is 1.4, and the average refractive index of the first transparent film layer 2 is 2.00.

[0133] The refractive index ratio of the front plate 5 to the second transparent film layer 4 is 1:1.43. The density of the second transparent film layer 4 is 3.9-5g / cm 3 In the direction from the front plate 5 to the light-receiving surface transparent adhesive film layer 3, the second transparent thin film layer 4 is a multi-layer transparent film layer, and the multi-layer transparent film layer is a composite film of a titanium dioxide film layer and a zinc oxide aluminum film layer arranged in sequence. The thickness of the titanium dioxide film layer accounts for 90% of the total thickness of the titanium dioxide film layer and the zinc oxide aluminum film layer.

[0134] The thickness ratio of the front plate 5, second transparent film layer 4, light-receiving transparent adhesive film layer 3, and cell 1 is 1:0.001:4.1:1. The thickness ratio of the back transparent adhesive film layer 6, back plate 7, and cell 1 is 4:1:1. The cell 1 is 120 μm thick.

[0135] The preparation process is as follows:

[0136] 1) Prepare a battery cell 1 and prepare an ETFE panel as the front plate 5 and the back plate 7.

[0137] 2) Depositing a high-refractive-index ITO thin film on the light-receiving surface of the cell 1. Specifically, magnetron sputtering is used for deposition, including: first performing a first sputtering for 5 minutes, then performing a second sputtering while applying a negative bias (5KV, 400Hz) to the back of the cell 1. The second sputtering time is calculated by subtracting the thickness of the first sputtering from the desired total thickness to obtain the desired second sputtering thickness, specifically 15 minutes. The conditions for controlling the first sputtering include the vacuum degree: 10 －1 Pa; sputtering power: 10kw. The vacuum degree of the second sputtering is 10 －2The second sputtering power was 7 kW, and a negative bias voltage was applied during the sputtering process. The target material was ITO, the sputtering voltage was 260 V, and a mixture of oxygen and argon with an oxygen content of 1.6% by volume was introduced. The ITO film thickness was 150 nm.

[0138] 3) Prepare a material for the second transparent film layer 4 having a refractive index greater than 2.0.

[0139] 4) Using an ETFE panel as a front plate 5, a second transparent film layer 4 is deposited on one side thereof. The second transparent film layer 4 is a composite film of a titanium dioxide film layer and a zinc aluminum oxide film layer. The specific deposition process and method of depositing the second transparent film layer 4 on the ETFE panel are as follows: 1) Titanium dioxide film layer: sputtering power 7KW, sputtering voltage: 420V, vacuum degree 10 －2 Pa, sputtering thickness 55nm; 2) ZnO aluminum film layer: sputtering power 7KW, sputtering voltage: 420V, vacuum degree 10 －2 Pa, sputtering thickness 22nm.

[0140] 5) Lay the back sheet 7, the back transparent adhesive film layer 6, the cell 1 with the first transparent film layer 2 deposited thereon, the light-receiving surface transparent adhesive film layer 3, and the front sheet 5 with the second transparent film layer 4 deposited thereon in sequence, and then laminate them, wherein the first transparent film layer 2 is located between the light-receiving surface of the cell 1 and the light-receiving surface transparent adhesive film layer 3, and the second transparent film layer 4 is located between the front sheet 5 and the light-receiving surface transparent adhesive film layer 3, ensuring that the layers are tightly fitted together to form a color-adjustable flexible photovoltaic module with a three-dimensional color pattern effect.

[0141] Example 2

[0142] The method used in Example 1 differs, except that step 4) is different. A mask is used to increase the variation in the film layer structure, forming different film layers in different areas. Three structures are arranged in sequence: the first structure comprises a titanium dioxide film layer and a zinc-aluminum oxide film layer, the second structure comprises only a titanium dioxide film layer, and the third structure comprises only a zinc-aluminum oxide film layer. These structures sequentially present yellow, light yellow, and off-white colors, respectively, to enrich the pattern colors of the color-adjustable flexible photovoltaic module. The specific steps are: attaching a mask material having a mask pattern to one side of the front panel, then depositing thin film materials of different materials and thicknesses on this side; after deposition is complete, removing the mask material to obtain a second transparent film layer.

[0143] Example 3

[0144] The process is carried out in accordance with Example 1, except that the first transparent film layer is zinc aluminum oxide.

[0145] Example 4

[0146] The method is carried out in accordance with Example 1, except that the density of the second transparent film layer is 3.8 mg / cm 3 The difference between the deposition conditions and Example 1 is that the sputtering power of the titanium dioxide film layer and the zinc oxide aluminum film layer are 5KW, and the vacuum degree is 10 －1 Pa.

[0147] Example 5

[0148] The same method is carried out as in Example 1, except that the thickness of the titanium dioxide film layer in the second transparent film layer accounts for 30%.

[0149] Example 6

[0150] Refer to Example 1, except that the second transparent film layer adopts a multi-layer transparent film layer, specifically a composite film of a titanium dioxide film layer, a zinc oxide aluminum film layer, and a titanium dioxide film layer arranged in sequence. The total thickness of the titanium dioxide film layer is the same as that of Example 1 and is evenly divided into two layers, the upper and the lower layers.

[0151] Example 7

[0152] The method is carried out in accordance with Example 1, except that the vacuum degree of the first sputtering is changed so that the ratio of the vacuum degree of the first sputtering to the vacuum degree of the second sputtering is 3:1, which makes the structure of the first transparent film layer comprise a first sputtering ITO film layer with a higher step coverage and a second sputtering ITO film layer with a higher step coverage. The average refractive index of the first transparent film layer is 2.05, and the density difference between the two ends of the first transparent film layer is 0.3 g / cm 3 , the average density is 7.05mg / cm 3 The velvet structure on the battery surface is still relatively sharp.

[0153] Example 8

[0154] The method is carried out in accordance with Example 1, except that the power of the first sputtering is changed so that the ratio of the power of the first sputtering to the power of the second sputtering is 1:1, which makes the structure of the first transparent film layer such that the sputtering ions of the first sputtering are fewer and the number of collisions is fewer, the difference in the number of ions received in the area with a large acceptance angle and the area with a small acceptance angle is smaller, the coverage of the formed ITO film layer is higher, and the deposition thickness is thinner, and the coverage of the low part of the suede surface is less. The average refractive index of the first transparent film layer is 2.1, and the density difference between the two ends of the first transparent film layer is 0.2 g / cm 3 , average density is 7.1mg / cm 3 The velvet structure on the battery surface is still relatively sharp.

[0155] Example 9

[0156] The method is carried out in accordance with Example 1, except that the first transparent film layer is a non-conductive transparent film layer: silicon nitride, and its preparation process is deposited by magnetron sputtering, including: first performing a first sputtering for 5 minutes, and then performing a second sputtering while applying a negative bias (5KV, 400Hz) to the back of the cell. The second sputtering time is obtained by subtracting the thickness of the first sputtering from the required total thickness to obtain the required second sputtering thickness, specifically 5 minutes; wherein the conditions for controlling the first sputtering include the vacuum degree: 10 －1 Pa; sputtering power: 10kw. The vacuum degree of the second sputtering is 10 －2 Pa, the second sputtering power is 7 kW, and a negative bias is applied during the sputtering process. The target material for the entire sputtering process is a silicon target, the sputtering voltage is 370 V, and a mixture of nitrogen and argon is introduced, wherein the nitrogen content is 3% by volume. The silicon nitride film thickness is about 80 nm. The average refractive index of the first transparent film layer is 2, and the density difference between the two ends of the first transparent film layer is 0.6 g / cm 3 , average density is 2.5mg / cm 3 .

[0157] Example 10

[0158] The same method as in Example 1 was used, except that the surface of the second transparent film layer 4, adjacent to the light-receiving transparent adhesive film layer 3, had a concave-convex structure 401. This concave-convex structure 401 formed a concave-convex structure throughout the second transparent film layer 4, resulting in interface differences at different locations. The thickness ratio of the front panel 5, second transparent film layer 4, light-receiving transparent adhesive film layer 3, and cell 1 was 1:0.001-0.002:4.1:1.

[0159] The corresponding specific preparation process includes: after 3) preparing the material of the second transparent film layer 4 with a refractive index greater than 2.0,

[0160] 4) Designing an imprinting mold with a multi-layer structure, wherein the imprinting mold includes concave-convex structures 401 of different depths and shapes.

[0161] 5) The ETFE panel is used as the front plate 5 and placed in an embossing device. By heating to 100°C and applying a pressure of 80 Pa, a multi-layered concave-convex structure 401 is formed on its surface, as shown in Figure 3. At this point, embossing marks of different depths and shapes appear on the ETFE panel.

[0162] 6) The ETFE panel with the multi-level concave-convex structure 401 is configured to deposit a second transparent thin film layer 4. As shown in FIG4 , the second transparent thin film layer 4 is a composite film of a titanium dioxide film layer and a zinc aluminum oxide film layer. The specific deposition process and method of depositing the second transparent thin film layer 4 on the ETFE panel are as follows: 1) Titanium dioxide film layer: sputtering power 7KW, sputtering voltage: 420V, vacuum degree 10 －2Pa, sputtering thickness 55nm; 2) ZnO aluminum film layer: sputtering power 7KW, sputtering voltage: 420V, vacuum degree 10 －2 Pa, sputtering thickness 22nm. Due to the presence of the concavo-convex structure 401 on the surface of the second transparent film layer 4, the film interface will change, thereby realizing a three-dimensional color pattern, presenting a laser-like effect of multiple colors with different brightness and saturation.

[0163] 7) Lay the back sheet 7, the back transparent adhesive film layer 6, the cell 1 with the first transparent film layer 2 deposited thereon, the light-receiving surface transparent adhesive film layer 3, and the front sheet 5 with the second transparent film layer 4 deposited thereon in sequence, and then laminate them, wherein the first transparent film layer 2 is located between the light-receiving surface of the cell 1 and the light-receiving surface transparent adhesive film layer 3, and the second transparent film layer 4 is located between the front sheet 5 and the light-receiving surface transparent adhesive film layer 3, ensuring that the layers are tightly fitted together to form a color-adjustable flexible photovoltaic module with a three-dimensional color pattern effect.

[0164] This technical solution achieves a three-dimensional, color-tunable pattern on flexible photovoltaic modules by applying multi-layer embossing and combining different embossing marks on ETFE. This method enhances the module's aesthetics and personalization. Furthermore, the preparation process is simple and easy to implement, demonstrating its high practical value.

[0165] This embodiment also has the following advantages:

[0166] Aesthetics: Through multi-level embossing and combining different embossing marks, rich three-dimensional color patterns can be achieved, which improves the visual effect of color photovoltaic modules and meets consumers' demand for aesthetics.

[0167] Personalization: Multi-level embossing and embossing marks of different shapes can form unique color patterns, providing users with more personalized choices and increasing the added value of the product.

[0168] Simple and easy: The preparation process of this technical solution is simple, does not require complicated equipment and operations, and is easy to promote and apply in engineering.

[0169] Wide range of applications: 3D color photovoltaic modules can be configured into building-integrated photovoltaics, household photovoltaic systems, mobile energy equipment and other fields, and have broad market prospects.

[0170] Comparative Example 1

[0171] The method is carried out in accordance with Example 1, except that the vacuum degree and sputtering power of the first sputtering are changed so as to be the same as the vacuum degree and sputtering power of the second sputtering, respectively. The structure of the first transparent thin film layer is that both the first sputtered ITO film and the second sputtered ITO film are ITO films with high step coverage, and the density and refractive index of the two layers are almost the same, with no density difference and refractive index difference (the density difference is basically 0). The refractive index of the first transparent thin film layer is 2.2, and the density of the first transparent thin film layer is 7.2 mg / cm 3 .

[0172] Comparative Example 2

[0173] The method is carried out in accordance with Example 1, except that the vacuum degree of the first sputtering is changed to be the same as the vacuum degree of the second sputtering, so that the structure of the first transparent film layer is a first sputtering ITO film layer with a higher step coverage and a second sputtering ITO film layer with a higher step coverage; and the density difference between the two ITO film layers is small, and the refractive index difference is also small. The density difference between the two ends of the first transparent film layer is 0.1 g / cm 3 , average density is 7.15mg / cm 3 The average refractive index of the first transparent film layer is 2.15. The suede structure on the surface of the battery is still relatively sharp.

[0174] Comparative Example 3

[0175] The method is carried out in accordance with Example 1, except that the average refractive index of the first transparent film layer is 1.6, and the density difference between the two ends of the first transparent film layer is 0.2 g / cm 3 , average density is 6.5mg / cm 3 The difference between the deposition conditions and those of Example 1 is that the second sputtering does not apply a negative bias, and the sputtering vacuum is 10 －1 Pa.

[0176] Test Case

[0177] The photovoltaic modules and the cells deposited with the first transparent film layer obtained in the above examples and comparative examples were subjected to performance tests, and the results are shown in Table 1.

[0178] Table 1

[0179] The above results show that, compared to the comparative example, the embodiments of the present disclosure can improve the color of the solar cell deposited with the first transparent film layer from dark blue to bright blue, and can also make the flexible photovoltaic module appear yellow or a variety of colors. The saturation of the flexible photovoltaic module is better than that of the comparative example, while maintaining essentially unchanged power generation. In contrast, the comparative example, with a small or no density difference in the first transparent film layer, cannot produce a flexible photovoltaic module with a bright (i.e., highly saturated) yellow color.

[0180] Furthermore, according to Examples 1 and 3 of the present disclosure, it can be seen that using ITO as an optional solution for the first transparent film layer is more conducive to improving the saturation of the flexible photovoltaic module and the color saturation of the battery cell deposited with the first transparent film layer than zinc oxide aluminum.

[0181] Furthermore, according to Examples 1 and 4-5 of the present disclosure, the solution of Example 1 using the density of the second transparent thin film layer and the thickness ratio of the titanium dioxide film layer is more conducive to improving the saturation of the flexible photovoltaic module while maintaining a higher power generation capacity.

[0182] Furthermore, according to Examples 1 and 6 of the present disclosure, it can be seen that the solution of Example 6 using the multi-layer structure of the second transparent thin film layer is more conducive to improving the saturation of the flexible photovoltaic module.

[0183] Furthermore, according to Example 1 and Examples 7-8 of the present disclosure, the embodiment 1 scheme using the first transparent film layer with a suitable density difference is more conducive to significantly improving the saturation of the flexible photovoltaic module and improving the color saturation of the cell deposited with the first transparent film layer.

[0184] Furthermore, according to Examples 1, 2 and 10 of the present disclosure, by providing second transparent thin film layers of different structures with different materials and thicknesses, a colorful flexible photovoltaic module can be obtained while taking into account high saturation.

[0185] The above describes in detail the optional embodiments of the present disclosure, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, various simple variations of the technical solution of the present disclosure can be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present disclosure and fall within the scope of protection of the present disclosure. Industrial Applicability

[0186] The present disclosure provides a color-adjustable flexible photovoltaic module, a preparation method, a solar cell, and applications. By arranging the first transparent film layer on the light-receiving surface of the cell and between the light-receiving surface of the cell and the transparent adhesive film layer on the light-receiving surface, the density of the first transparent film layer at one end close to the light-receiving surface of the cell is less than the density at the other end of the first transparent film layer, and the density difference between the two ends is 0.2-1.8 g / cm3, the average refractive index of the first transparent film layer is 1.8-2.2, and the second transparent film layer is arranged between the front plate and the transparent adhesive film layer on the light-receiving surface, a color-adjustable flexible photovoltaic module with high saturation and different colors can be obtained.

Claims

1. A color-adjustable flexible photovoltaic module, comprising a cell, a light-receiving transparent adhesive film layer and a front plate arranged on the light-receiving side of the cell, a back transparent adhesive film layer and a back plate arranged on the back of the cell, It is characterized in that The invention also includes a first transparent film layer and a second transparent film layer, wherein the first transparent film layer is arranged on the light-receiving surface of the battery cell and is located between the light-receiving surface of the battery cell and the transparent adhesive film layer on the light-receiving surface, and the density of the first transparent film layer at one end close to the light-receiving surface of the battery cell is less than the density of the other end of the first transparent film layer, and the density difference between the two ends is 0.2-1.8 g / cm 3 The average refractive index of the first transparent film layer is 1.8-2.2; the second transparent film layer is arranged between the front plate and the light-receiving surface transparent adhesive film layer.

2. The color-adjustable flexible photovoltaic module according to claim 1, It is characterized in that The average density of the first transparent film layer is 2.2-7.2 g / cm 3 ; And / or, the thickness of the first transparent film layer is 100-180 nm.

3. The color-adjustable flexible photovoltaic module according to claim 1 or 2, It is characterized in that The first transparent film layer includes a transparent conductive film layer and / or a non-conductive transparent film layer, the transparent conductive film layer is a doped oxide containing doped elements, the oxide in the doped oxide includes at least one of indium oxide, zinc oxide, and tin oxide, the doping element includes at least one of tin, aluminum, fluorine, and silver, and the non-conductive transparent film layer includes at least one of silicon nitride, silicon oxide, silicon oxynitride, silicon carbide, and titanium nitride.

4. The color-adjustable flexible photovoltaic module according to claim 3, It is characterized in that The first transparent film layer is at least one of tin-doped indium oxide, zinc-aluminum oxide, fluorine-doped tin oxide, and silver-doped zinc oxide.

5. The color-adjustable flexible photovoltaic module according to claim 3 or 4, It is characterized in that When the first transparent film layer is a transparent conductive film layer, the average density is 5.5-7.2 g / cm 3 When the first transparent film layer is a non-conductive transparent film layer, the average density is 2.2-3.2 g / cm 3 .

6. The color-adjustable flexible photovoltaic module according to any one of claims 1 to 5, It is characterized in that The ratio of the refractive index of the front plate to the average refractive index of the first transparent film layer is 1:1.28-1.

5.

7. The color-adjustable flexible photovoltaic module according to any one of claims 1 to 6, It is characterized in that The light-receiving surface of the battery cell is a velvet surface.

8. The color-adjustable flexible photovoltaic module according to any one of claims 1 to 7, It is characterized in that The thickness ratio of the front plate, the second transparent film layer, the light-receiving surface transparent adhesive film layer and the battery sheet is 1-3:0.0006-0.0025:3-8:

1.

9. The color-adjustable flexible photovoltaic module according to any one of claims 1 to 8, It is characterized in that A surface of the second transparent film layer close to the light-receiving transparent adhesive film layer has a concavo-convex structure.

10. The color-adjustable flexible photovoltaic module according to claim 9, It is characterized in that The concavo-convex structure enables the overall thickness of the second transparent film layer to be between 50 and 500 nm; and / or the second transparent film layer is at least one of titanium dioxide, zirconium dioxide, zinc aluminum oxide and niobium pentoxide.

11. The color-adjustable flexible photovoltaic module according to any one of claims 1 to 11, It is characterized in that The ratio of the refractive index of the front plate to the second transparent film layer is 1:1.28-1.93, and the refractive index of the second transparent film layer is greater than 1.8; and / or The density of the second transparent film layer is 3.8-6.9 g / cm 3 between.

12. The color-adjustable flexible photovoltaic module according to claim 11, It is characterized in that The second transparent film layer is a single-layer transparent film layer with a refractive index greater than 2.0, or a multi-layer transparent film layer with a refractive index difference between adjacent transparent film layers, the absolute value of the refractive index difference is between 0.3 and 1, and the refractive index of each film layer in the multi-layer transparent film layer presents a non-increasing or non-decreasing change.

13. The color-adjustable flexible photovoltaic module according to claim 12, It is characterized in that The single-layer transparent film with a refractive index greater than 2.0 is a titanium dioxide film or a zirconium dioxide film; the multi-layer transparent film is a combination of a titanium dioxide film and one or more selected from zinc aluminum oxide film, indium tin oxide film, and niobium pentoxide.

14. The color-adjustable flexible photovoltaic module according to claim 13, It is characterized in that In the direction from the front plate to the transparent adhesive film layer on the light-receiving surface, the multilayer transparent film layer is a composite film of a titanium dioxide film layer and a zinc oxide aluminum film layer arranged in sequence, or a composite film of a titanium dioxide film layer, a zinc oxide aluminum film layer, and a titanium dioxide film layer arranged in sequence.

15. The color-adjustable flexible photovoltaic module according to claim 13 or 14, It is characterized in that When the required saturation is 50%-55%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 90%-100% of the total thickness of the second transparent film layer; When the required saturation is 40%-49%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 60%-89% of the total thickness of the second transparent film layer; When the required saturation is 35%-39%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 31%-59% of the total thickness of the second transparent film layer; When the required saturation is 25%-34%, the thickness of the titanium dioxide film layer in the second transparent film layer is controlled to account for 0%-30% of the total thickness of the second transparent film layer.

16. A method for preparing a color-adjustable flexible photovoltaic module. It is characterized in that The preparation method comprises the following steps: S1. Depositing a first transparent thin film layer on the light-receiving surface of the cell by magnetron sputtering, wherein the process of depositing by magnetron sputtering comprises: first performing a first sputtering for 3-8 minutes, and then performing a second sputtering while applying a negative bias voltage to the back of the cell; wherein the vacuum degree of the first sputtering is controlled to be lower than the vacuum degree of the second sputtering; the power of the first sputtering is ≥ the power of the second sputtering, and the vacuum degree of the second sputtering is 5×10 －1 -5×10 －2 Pa, the power of the second sputtering is 6-9kw; S2, first depositing a second transparent thin film layer on one side of the front plate; S3, sequentially laying a back plate, a back transparent adhesive film layer, a battery cell with a first transparent film layer deposited thereon, a light-receiving surface transparent adhesive film layer, and a front plate with a second transparent film layer deposited thereon, and then laminating them, wherein the first transparent film layer is located between the light-receiving surface of the battery cell and the light-receiving surface transparent adhesive film layer, and the second transparent film layer is located between the front plate and the light-receiving surface transparent adhesive film layer; After deposition, the density of one end of the first transparent film layer close to the light-receiving surface of the cell is less than the density of the other end of the first transparent film layer.

17. The preparation method according to claim 16, It is characterized in that The ratio of the vacuum degree of the first sputtering to the vacuum degree of the second sputtering is 3-10:1, and the ratio of the power of the first sputtering to the power of the second sputtering is 1-1.8:1; And / or, the negative bias conditions include: an applied voltage of 3-8 kV and an applied frequency of 300-500 Hz.

18. The preparation method according to claim 16 or 17, It is characterized in that The process of depositing the second transparent thin film layer with a concavo-convex structure in S2 includes the steps of controlling the material, thickness, and position of the required film layer according to the required color, and specifically includes any one of the following methods a-d: a. Imprinting one side of the front plate with an imprinting mold having a desired concave-convex structure to obtain a front plate with a concave-convex structure; then depositing a second transparent thin film layer on the concave-convex structure side of the front plate; b. attaching a mask material having a mask pattern to one side of the front plate, and then depositing thin film materials of different materials and thicknesses on the surface; After the deposition is completed, the mask material is removed to obtain a second transparent thin film layer; c. Depositing thin film materials of different thicknesses and materials on one side of the front plate, laser scribing different areas of the thin film materials to remove a portion of the thin film materials, and then forming desired patterns of different thicknesses and / or different shapes by laser scribing to obtain a second transparent thin film layer; d. Provide a mask plate with different spacing areas, maintain different spacing distances between the mask plate and one side of the front plate, then deposit a second transparent thin film layer within the distance, and then remove the mask plate to obtain the second transparent thin film layer.

19. A color-adjustable flexible photovoltaic module. It is characterized in that The color-adjustable flexible photovoltaic module is prepared by the method for preparing the color-adjustable flexible photovoltaic module described in any one of claims 16 to 18.

20. A solar cell, It is characterized in that The invention comprises a color-adjustable flexible photovoltaic module as claimed in any one of claims 1 to 15 and claim 19.

21. Use of the solar cell according to claim 20 in a sunshade device and / or a solar energy device.

22. Use of the solar cell according to claim 21 in a sunshade device and / or a solar energy device, It is characterized in that The shading device includes a shading device or cover installed on at least one of an RV, a camper, a store, a vending machine, and a swimming pool, and the solar energy device includes a solar power generation device installed on at least one of a terrace, a balcony, a rooftop, a garden fence, a fence, a wall, a window, and a driveway outside a garage.

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