Colored photovoltaic modules and their manufacturing methods

Abstract

This invention relates to the field of photovoltaic module technology, and in particular to a colored photovoltaic module and its manufacturing method. The colored photovoltaic module has a light-converting pattern inside or on its surface. The light-converting pattern is composed of light-converting pixels, used to make the light-converting pattern display a desired color pattern under illumination. Each light-converting pixel contains a light-converting color block, and the light-converting color of the color block corresponds to a basic color. The proportion of light-converting color blocks of different colors within the pixel determines the desired color displayed by the light-converting pixel under illumination. The manufacturing method of the aforementioned colored photovoltaic module includes the following steps: A) preparing light-converting adhesives of different light-converting colors; B) printing; C) encapsulating the photovoltaic cell with a light-converting encapsulation layer. The beneficial effects are: by converting light through the light-converting color blocks, the photoelectric conversion efficiency is increased, and the photovoltaic module can display a full-color pattern under sunlight, greatly increasing its aesthetic appeal. The manufacturing method is compatible with existing photovoltaic module production lines.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module technology, and in particular to a colored photovoltaic module and its preparation method. Background Technology

[0002] Colored photovoltaic modules can enhance the aesthetics of photovoltaic modules. The colored patterns on colored photovoltaic modules can be monochrome or multi-colored.

[0003] However, existing photovoltaic modules often sacrifice power generation efficiency to display colored patterns. The first type of method to achieve colored photovoltaic modules is to selectively reflect light of specific colors by adjusting the thickness of the passivation protective layer on the surface of the photovoltaic cell, such as SiNX, SiO2, or ITO thin film, thereby coloring the photovoltaic cell and obtaining a colored photovoltaic module.

[0004] A second method for achieving colored photovoltaic modules is to deposit a thin film layer on the glass panel of the photovoltaic module. By adjusting the thickness of this transparent thin film layer (such as SiOx), the photovoltaic module can also be colored, resulting in a colored photovoltaic module. The principle is the same as adjusting the thickness of the thin film layer on the surface of the battery.

[0005] A third method to achieve colored photovoltaic modules is to print colored resin pigments on the glass panel of the photovoltaic module to color the photovoltaic module and obtain a colored photovoltaic module.

[0006] The fourth method to achieve colored photovoltaic modules is to use laser etching technology for thin-film batteries such as CdTe for coloring. The principle is also to adjust the thickness of the thin film, which can result in more detailed colored patterns.

[0007] Overall, all of the above methods will reduce power generation efficiency. Red photovoltaic modules suffer an efficiency loss of about 15%, while other colored photovoltaic modules suffer losses of about 20%-50%.

[0008] The applicant has filed a patent application for a patterned photovoltaic module and its fabrication method. In this patent application, a colored pattern is formed on the surface of the photovoltaic module through patterned gaps in the encapsulation material. The advantage of this technical solution is that the blue pattern is reflected only at a specific angle, while having virtually no impact on the absorption of perpendicularly incident light. Therefore, it has little impact on the photoelectric conversion efficiency of the photovoltaic module. Compared with traditional colored photovoltaic modules, the photoelectric conversion efficiency loss is reduced by one order of magnitude, typically around 1-2%.

[0009] While this technical solution significantly reduces the loss of photoelectric conversion efficiency compared to traditional colored photovoltaic modules, some loss still exists. Furthermore, it is difficult to achieve full-color manufacturing with colors other than "sapphire blue." Additionally, it suffers from low compatibility with existing photovoltaic module production equipment and materials, resulting in higher costs. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a colored photovoltaic module and its preparation method, which can further improve the photoelectric conversion efficiency of the colored photovoltaic module, realize more color patterns, and has high compatibility with existing photovoltaic module production equipment and materials, and low cost.

[0011] The technical solution adopted by the present invention to solve its technical problem is: a colored photovoltaic module, having a light-converting pattern inside or on the surface, the light-converting pattern being composed of light-converting pixels, used to make the light-converting pattern present the desired color pattern under illumination, the light-converting pixels having light-converting color blocks, the light-converting color of the light-converting color blocks corresponding to a basic color, the light-converting pixels presenting the desired color under illumination by the proportion of light-converting color blocks of different light-converting colors within the pixel, the light-converting pixels being a transparent thin layer mixed with a light-converting material of the corresponding color.

[0012] In some embodiments, the light-converting color of the light-converting color block can be one of the basic colors of RGB or CMYK.

[0013] In some embodiments, optionally, the colored photovoltaic module includes photovoltaic cells and encapsulation layers for encapsulating the photovoltaic cells, with light-converting color blocks distributed on the surface of one of the encapsulation layers.

[0014] In some embodiments, optionally, the colored photovoltaic module includes a panel layer, a front encapsulant layer, a photovoltaic cell layer, a back encapsulant layer, and a backsheet layer, wherein the panel layer, the front encapsulant layer, the photovoltaic cell layer, the back encapsulant layer, and the backsheet layer are arranged from top to bottom, and the light-converting color blocks are distributed on the back surface of the panel layer, or the light-converting color blocks are distributed on the surface of the front encapsulant layer.

[0015] In some embodiments, the light-converting color block may be formed by curing an adhesive mixed with a light-converting material of the corresponding color.

[0016] A method for preparing the above-mentioned colored photovoltaic module, characterized by comprising the following steps: A. Prepare light-converting adhesives of different light-converting colors. Each light-converting adhesive corresponds to a basic color. The light-converting adhesive is an adhesive mixed with the corresponding light-converting material. B. Printing: According to the designed light-conversion pattern, light-conversion adhesive of different colors is printed onto the surface of the encapsulation layer of the photovoltaic cell using a printing process. After the light-conversion adhesive is cured, a light-conversion encapsulation layer with a light-conversion pattern is obtained. C. Photovoltaic cells are encapsulated using encapsulation materials containing a light-converting encapsulation layer to obtain colored photovoltaic modules.

[0017] In some embodiments, optionally, the printing process specifically adopts a color screen printing process, in which each type of gloss-converting adhesive is printed through a matching screen printing plate, one type of gloss-converting adhesive is printed at a time, and the gloss-converting adhesive is fixed after each printing.

[0018] In some embodiments, the light-converting pattern is optionally derived from the desired color pattern based on the principle of digital display. During the conversion, the pixels of the color pattern are converted into a combination of different basic color blocks of different sizes, and then the light-converting color blocks are used to replace the basic color blocks of the same color to obtain the light-converting pattern.

[0019] In some embodiments, optionally, during conversion, when the color of a pixel is the same as the substrate color, the proportion of the base color block that is the same as the pixel color within the pixel is the largest, while the proportion of other substrate color blocks within the pixel is the smallest, which is zero.

[0020] In some embodiments, the color pattern may be selectively reduced during conversion to decrease the area of ​​light blocking.

[0021] The beneficial effects of this invention are: 1. By converting light into light through light-converting color blocks, light in the low-utilization frequency range can be converted into light, which can then be utilized by photovoltaic cells, increasing photoelectric conversion efficiency. On the other hand, by using a few light-converting color blocks and adjusting their proportion, photovoltaic modules can display full-color patterns under sunlight, greatly increasing aesthetics. 2. The preparation method is compatible with existing photovoltaic module production lines, which can greatly reduce costs and realize the mass production of colored photovoltaic modules. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a flowchart illustrating the preparation process of the present invention; Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the structure of pixels at a local location in this invention; In the image, 1. Light-converting glass panel, 2. EPE film, 3. Heterojunction photovoltaic cell string, 4. Glass backsheet, 5. Light-converting color block, 5-1. Red light-converting color block, 5-2. Green light-converting color block, 5-3. Blue light-converting color block, 6. Glass panel, 7. Light-converting POE film, 8. IBC photovoltaic cell string, 9. POE film, 10. Light-converting pixel. Detailed Implementation

[0023] Example 1: A colored photovoltaic module has a light-converting pattern inside. The light-converting pattern is composed of light-converting pixels 10, which are used to make the light-converting pattern present the desired color pattern under light. Each light-converting pixel 10 has a light-converting color block 5. The light-converting color of the light-converting color block 5 corresponds to a basic color. The proportion of light-converting color blocks 5 of different light-converting colors in the pixel 10 makes the light-converting pixel 10 present the desired color under light. The light-converting color block 5 is a transparent thin layer mixed with a light-converting material of the corresponding color.

[0024] According to the spectral response curve of photovoltaic cells, photovoltaic cells have low utilization efficiency for violet and infrared light. The light-converting material in light-converting color block 5 can convert the violet and infrared light, which have low utilization efficiency in photovoltaic cells, into colored light. The light-converting material is also called an optical frequency conversion material.

[0025] The light-converting color of color block 5 is one of the three primary colors of RGB. The three primary colors of RGB are red, green and blue. Accordingly, there are three types of light-converting color blocks 5: red light-converting color block 5-1, green light-converting color block 5-2 and blue light-converting color block 5-3.

[0026] The colored photovoltaic module includes photovoltaic cells and various encapsulation layers for encapsulating the photovoltaic cells. The light-converting color blocks 5 are distributed on the surface of one of the encapsulation layers. Each encapsulation layer includes a panel layer, a front encapsulant layer, a back encapsulant layer, and a backsheet layer. The panel layer, front encapsulant layer, photovoltaic cell layer, back encapsulant layer, and backsheet layer are arranged from top to bottom, and the light-converting color blocks 5 are distributed on the back side of the panel layer.

[0027] The light-converting color block 5 is formed by curing a light-converting adhesive, which is an adhesive mixed with a light-converting material of the corresponding color. The light-converting color block 5 can be prepared using a printing process, which is compatible with existing printing equipment and reduces costs.

[0028] In this embodiment, the light-converting pattern is derived from the desired color pattern based on digital display principles. During the conversion, the pixels of the color pattern are transformed into combinations of different basic color blocks. Then, light-converting color blocks 5 replace the basic color blocks of the same color to obtain the light-converting pattern. During the conversion, when the pixel color is the same as the substrate color, the basic color block of the same color as the pixel occupies the largest proportion within the pixel, while the substrate color blocks of other colors occupy the smallest proportion, which is zero. For example, when the pixel color is red, the red block within the pixel is the largest, covering the entire pixel, while the green and blue blocks are the smallest, which is zero. Alternatively, a pixel could contain multiple color blocks, all of which are red. This design helps reduce light shading. That is, only the type of basic color block is limited, not the number of basic color blocks. By adjusting the overall size of all the same basic color blocks within the pixel, pixels of various colors can be mixed.

[0029] The principle of digital display is that colored patterns are displayed by pixels, and each pixel has three sub-pixels: red, green, and blue. By adjusting the brightness of the sub-pixels, pixels of various colors are mixed. The principle of this embodiment is basically the same as that of digital display, the difference being that various colors of pixels are mixed by adjusting the proportion of the three basic color blocks (red, green, and blue) within the pixel.

[0030] Colored patterns can be reduced during conversion to decrease the area obstructing light, for example, by using Fourier convolution image processing or other image processing methods.

[0031] When sunlight shines on the surface of the colored photovoltaic module in Embodiment 1, the light-converting material converts the light in low-utilization frequency bands (such as ultraviolet and infrared light) into light of the target frequency. The converted light can be utilized by the photovoltaic cells, increasing the photoelectric conversion efficiency. On the other hand, the converted light can make the photovoltaic module display colored patterns under sunlight, increasing the aesthetics of the photovoltaic module.

[0032] Light conversion materials can utilize the colored light conversion powder from the LED industry to reduce costs; alternatively, quantum dot phosphors can be used to enhance the extreme color accuracy or light conversion efficiency.

[0033] The colored photovoltaic module in this embodiment 1 is specifically a heterojunction battery colored photovoltaic module. The panel layer is a light-converting glass panel 1 with a light-converting pattern on the back. The front and back encapsulant layers are EPE encapsulant films 2. The photovoltaic cell layer is a heterojunction photovoltaic cell string 3. The backsheet layer is a glass backsheet 4.

[0034] The method for fabricating this heterojunction colored photovoltaic module includes the following steps: A. Prepare three types of light-converting adhesive: red, green, and blue (RGB light-converting adhesive). The red light-converting adhesive will produce a red light-converting color, the green light-converting adhesive will produce a green light-converting color, and the blue light-converting adhesive will produce a blue light-converting color. The light-converting adhesive is an adhesive mixed with the corresponding color light-converting material.

[0035] The preparation method of the red light-converting material in the red light-converting adhesive is as follows: a solid reaction is carried out using the ratio of CdO (0.92): MoO3 (1): Eu2O3 (0.02): LiF (0.04) to obtain the red light-converting material.

[0036] The preparation method of the green light-converting material in the green light-converting adhesive is as follows: using CaCO3, Gd2O3, GeO2, and Tb4O7 as raw materials, CaGd is prepared at high temperature. 1.0 Ge4O 12 1.0Tb 3+ This is a white powder that is a green light-converting material. It can be effectively excited by excitation light of 300~400nm and emit green light with a wavelength of 543nm.

[0037] The preparation method of the blue light-converting material in the blue light-converting adhesive is as follows: the blue light-converting material is Sr2B5O9Cl:Eu 2+ This blue light-converting material is synthesized via a high-temperature solid-state method. It can absorb ultraviolet light in the range of 250-400 nm and emit blue light in the range of 400-520 nm.

[0038] The above light-converting materials are incorporated into a polymer adhesive containing a UV curing trigger to produce a red light-converting adhesive containing a red light-converting material, a blue light-converting adhesive containing a blue light-converting material, and a green light-converting adhesive containing a green light-converting material.

[0039] B. Printing: According to the designed light-converting pattern, red, green and blue light-converting adhesives are printed onto the surface of the encapsulation layer of the photovoltaic cell, i.e. the back of the panel layer, using a printing process. After the light-converting adhesive is cured, a light-converting encapsulation layer with a light-converting pattern is obtained, i.e., the light-converting glass panel 1.

[0040] The printing process in this step is a color screen printing process. Each type of gloss-converting adhesive is printed using a matching screen printing plate. One type of gloss-converting adhesive is printed at a time, and the gloss-converting adhesive is fixed after each printing.

[0041] Red gloss-converting adhesive comes with a red screen printing stencil, green gloss-converting adhesive comes with a green screen printing stencil, and blue gloss-converting adhesive comes with a blue screen printing stencil.

[0042] The preparation methods for the three types of screen printing stencils are as follows: the light-converting pattern to be printed is decomposed according to the light-converting color into a red light-converting pattern, a green light-converting pattern, and a blue light-converting pattern, and then a matching screen printing stencil is prepared according to these three light-converting patterns.

[0043] First, a red screen printing plate is used to print red light-converting adhesive onto the back of the glass panel 6, followed by UV curing. Then, a green screen printing plate is used to print green light-converting adhesive onto the back of the glass panel 6, followed by UV curing. Finally, a blue screen printing plate is used to print blue light-converting adhesive onto the back of the glass panel 6, followed by UV curing. Through these steps, light-converting color blocks 5 of different sizes can be fixed to the back of the glass panel 6, completing the preparation of the light-converting glass panel 1 with a light-converting pattern.

[0044] C. Photovoltaic cells are encapsulated using encapsulation materials containing a light-converting encapsulation layer to obtain colored photovoltaic modules.

[0045] The specific steps are as follows: heterojunction photovoltaic cells are welded into strings using a stringer to obtain heterojunction photovoltaic cell string 3. Following the conventional photovoltaic module manufacturing method, a light-converting glass panel 1 is used instead of the conventional glass panel 6. The light-converting glass panel 1, EPE film 2, heterojunction photovoltaic cell string 3, EPE film 2, and glass backsheet 4 are arranged in sequence and then laminated and cured at high temperature to form the final product, namely the heterojunction battery colored photovoltaic module.

[0046] Example 2, a colored photovoltaic module and its preparation method, is basically the same as Example 1, except that: the colored photovoltaic module in this Example 2 is specifically an IBC back junction cell colored photovoltaic module.

[0047] The IBC back-junction colored photovoltaic module has a glass panel 6 as its front panel, a light-converting POE film 7 with a light-converting pattern as its front encapsulant layer, a POE film 9 as its back encapsulant layer, an IBC photovoltaic cell string 8 as its photovoltaic cell layer, and a glass backsheet 4 as its backsheet layer. The glass panel 6, the light-converting POE film 7, the IBC photovoltaic cell string 8, the POE film 9, and the glass backsheet 4 are arranged from top to bottom.

[0048] The following describes the preparation method of the IBC back junction cell colored photovoltaic module. The parts that are the same as in Example 1 will not be described in detail.

[0049] The method for fabricating this IBC back-junction colored photovoltaic module includes the following steps: A. Prepare three types of light-converting adhesives: red, green, and blue. The red, green, and blue light-converting materials in these adhesives can be selected from agricultural, lighting, and display phosphors, or from quantum dot phosphors. These adhesives can convert ultraviolet light below 400nm into red, green, or blue light, respectively.

[0050] B. Printing: The red light-converting color block 5-1, the green light-converting color block 5-2 and the blue light-converting color block 5-3 are printed onto the surface of the POE film 9 using a color screen printing process. After the light-converting adhesive is cured, a light-converting POE film 7 with a light-converting pattern is obtained.

[0051] C. The IBC photovoltaic cells are welded into strings using a stringer to obtain IBC photovoltaic cell string 8. Following the conventional photovoltaic module manufacturing method, the conventional POE film 9 is replaced with light-converting POE film 7. The glass panel 6, light-converting POE film 7, IBC photovoltaic cell string 8, POE film 9, and glass back sheet 4 are arranged in sequence and then laminated and cured at high temperature to form the final product, namely the IBC back junction cell colored photovoltaic module.

[0052] Example 3, a colored photovoltaic module and its preparation method, is basically the same as Example 1, except that: the adhesive for the light-converting adhesive is a heat-curing or radiation-curing adhesive, and after the light-converting adhesive is printed, it is cured by heating or radiation.

[0053] Example 4: A colored photovoltaic module and its preparation method are basically the same as in Example 1, except that the light-converting color of the light-converting color block 5 is one of the four primary colors of CMYK. The four primary colors of CMYK include four basic colors: cyan, magenta, yellow, and black. Correspondingly, there are also four light-converting color blocks 5: cyan, magenta, yellow, and black.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0055] For example, if other primary color systems exist in the prior art, it is not excluded that the present invention may adopt other primary color systems; Of course, it is also possible that the light-converting adhesive is printed onto the surface of the encapsulation layer using other printing methods.

Claims

1. A colored photovoltaic module, characterized in that: The interior or surface has a light-converting pattern, which is composed of light-converting pixels (10) and is used to make the light-converting pattern present the desired color pattern under light. The light-converting pixel (10) has a light-converting color block (5), and the light-converting color of the light-converting color block (5) corresponds to a basic color. The light-converting pixel (10) presents the desired color under light by the proportion of light-converting color blocks (5) of different light-converting colors in the pixel. The light-converting color block (5) is a transparent thin layer mixed with the corresponding color light-converting material.

2. The colored photovoltaic module according to claim 1, characterized in that: The light-converting color of the light-converting color block (5) is one of the basic colors of RGB or CMYK.

3. The colored photovoltaic module according to claim 1, characterized in that: The photovoltaic cell and the encapsulation layers of the photovoltaic cell are included, and the light-converting color blocks (5) are distributed on the surface of one of the encapsulation layers.

4. The colored photovoltaic module according to claim 1, characterized in that: It includes a panel layer, a front adhesive film layer, a photovoltaic cell layer, a back adhesive film layer and a back sheet layer. The panel layer, the front adhesive film layer, the photovoltaic cell layer, the back adhesive film layer and the back sheet layer are arranged from top to bottom. The light-converting color blocks (5) are distributed on the back surface of the panel layer, or the light-converting color blocks (5) are distributed on the surface of the front adhesive film layer.

5. The colored photovoltaic module according to claim 1, characterized in that: The light-converting color block (5) is formed by curing glue mixed with light-converting materials of the corresponding color.

6. A method for preparing a colored photovoltaic module as described in claim 1 or 2, characterized in that: Includes the following steps: A. Prepare light-converting adhesives of different light-converting colors. Each light-converting adhesive corresponds to a basic color. The light-converting adhesive is an adhesive mixed with the corresponding light-converting material. B. Printing: According to the designed light-conversion pattern, light-conversion adhesive of different colors is printed onto the surface of the encapsulation layer of the photovoltaic cell using a printing process. After the light-conversion adhesive is cured, a light-conversion encapsulation layer with a light-conversion pattern is obtained. C. Photovoltaic cells are encapsulated using encapsulation materials containing a light-converting encapsulation layer to obtain colored photovoltaic modules.

7. The method for preparing a colored photovoltaic module according to claim 6, characterized in that: The printing process specifically adopts a color screen printing process. Each type of gloss-converting adhesive is printed through a matching screen printing plate, with one type of gloss-converting adhesive printed at a time, and the gloss-converting adhesive is fixed after each printing.

8. The method for preparing a colored photovoltaic module according to claim 6, characterized in that: The light-converting pattern is derived from the desired color pattern based on the principle of digital display. During the conversion, the pixels of the color pattern are converted into a combination of different basic color blocks of different sizes. Then, the light-converting color block (5) replaces the basic color block of the same color to obtain the light-converting pattern.

9. The method for preparing a colored photovoltaic module according to claim 8, characterized in that: During the conversion, when the color of a pixel is the same as the base color, the proportion of the base color block that is the same as the pixel color within the pixel is the largest, while the proportion of other base color blocks within the pixel is the smallest, which is zero.

10. The method for preparing a colored photovoltaic module according to claim 8, characterized in that: The colored patterns are reduced during the conversion process to decrease the area that blocks light.

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