Building integrated photovoltaic module and method of manufacturing the same

Abstract

The application relates to the technical field of photovoltaic modules, in particular to a building integrated photovoltaic (BIPV) module and a preparation method thereof. The BIPV module comprises a color interference film layer, a cover glass and a photovoltaic cell piece which are sequentially stacked. The cover glass has a rough structure on the side facing the color interference film layer. The color interference film layer comprises an interference main body layer, the interference main body layer comprises a plurality of first film layers and a plurality of second film layers, the refractive index of the first film layers is greater than that of the second film layers, the plurality of first film layers and the plurality of second film layers are alternately arranged along the stacking direction, and the second film layers are arranged between any two adjacent first film layers, and the first film layers are arranged between any two adjacent second film layers. The color BIPV module can present the required color and utilize light energy.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module technology, and more specifically, to a building-integrated photovoltaic module and its preparation method. Background Technology

[0002] With the development of Building Integrated Photovoltaics (BIPV), building facades and roofs are gradually becoming important carriers of photovoltaic systems. Related components not only need to meet power generation requirements but also need to consider the building's appearance and landscape harmony. Currently, colored BIPV components mainly fall into two categories: one type involves applying colored pigments or thin films to the surface of the photovoltaic module, achieving color through shading or selective transmission. However, this method significantly impacts the utilization of incident light, leading to a decrease in power generation performance. The other type uses body-tinted glass as a cover plate, which presents color by absorbing different wavelengths of light. However, it exhibits strong overall light absorption, further affecting power generation performance. It also suffers from limited color representation and color shift issues under changing viewing angles.

[0003] Furthermore, in applications such as historical preservation buildings and urban landscape architecture, colored BIPV modules struggle to balance color matching and power generation performance, thus limiting their application. These issues primarily stem from their reliance on light absorption or shading methods to achieve color representation, making it difficult to strike a balance between light transmission characteristics and color stability. Summary of the Invention

[0004] The purpose of this application is to provide a building-integrated photovoltaic (BIPV) module and its preparation method, aiming to solve the technical problem that there is a mutual constraint between the color presentation mode and light energy utilization in the related art of colored BIPV modules.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: This application provides a building-integrated photovoltaic (BIPV) module, comprising: a color interference film layer, a cover glass, and photovoltaic cells stacked sequentially; The side of the cover glass facing the colored interference film has a rough structure; The color interference film includes an interference host layer, which includes multiple first films and multiple second films, wherein the refractive index of the first films is greater than the refractive index of the second films. Multiple first film layers and multiple second film layers are alternately arranged along the stacking direction, wherein a second film layer is located between two adjacent first film layers, and a first film layer is located between two adjacent second film layers.

[0006] In some implementations, the rough structure includes multiple groove structures and multiple protrusion structures, which are alternately arranged along the surface direction of the cover glass. Along the direction perpendicular to the surface of the cover glass, the distance between the bottom of the groove structure and the top of the protrusion structure is 0.5μm to 2μm; the distance between the bottoms of two adjacent groove structures along the direction of the cover glass surface is 2μm to 5μm.

[0007] In some implementations, the color interference film layer further includes a surface protective layer, and the interference body layer is located between the surface protective layer and the cover glass.

[0008] In some implementations, the refractive index of the first film layer is 1.9 to 2.1; the refractive index of the second film layer is 1.45 to 1.47. The material of the first film layer includes one or more of TiO2 and SiNx; the material of the second film layer includes SiO2.

[0009] In some implementations, the sum of the number of the plurality of first films and the plurality of second films is 12 to 18; the thickness of the interference host layer is 500 nm to 1000 nm.

[0010] This application provides a method for manufacturing a building-integrated photovoltaic (BIPV) module, used to manufacture the BIPV module described in any of the above implementations, comprising: A rough texture is machined onto one surface of the cover glass; An interference host layer is formed on the surface of the cover glass with a rough structure, wherein the interference host layer comprises a plurality of first film layers and a plurality of second film layers that are alternately stacked; The composite structure formed by the cover glass and the interference body layer is assembled with the photovoltaic cells.

[0011] In some implementations, the roughening of one surface of the cover glass includes: The surface of the cover glass is processed by etching to form multiple groove structures and multiple protrusion structures that are alternately arranged along the surface direction of the cover glass.

[0012] In some implementations, forming an interference host layer on the surface of the cover glass with a rough structure includes: A first film layer and a second film layer are formed on the surface of the cover glass with a rough structure by a sputtering process, wherein the sum of the number of the plurality of first film layers and the plurality of second film layers is 12 to 18, and the thickness of the interference host layer is 500 nm to 1000 nm.

[0013] In some implementations, before assembling the composite structure formed by the cover glass and the interference body layer with the photovoltaic cells, the method for preparing the building-integrated photovoltaic module further includes: The composite structure formed by the cover glass and the interference body layer is annealed at a first temperature for a first set time, wherein the first temperature is 200℃~220℃ and the first set time is 1.5h~2.5h.

[0014] In some implementations, after forming the interference host layer on the rough-structured surface of the cover glass, the method for fabricating the building-integrated photovoltaic module further includes: A surface protective layer is formed on the side of the interference body layer away from the cover glass using a deposition process, wherein the thickness of the surface protective layer is 70nm~100nm.

[0015] The main advantages of the building-integrated photovoltaic (BIPV) module and its manufacturing method provided in this application are as follows: This application utilizes a color interference film layer to selectively interfere and reflect incident light between multiple first and second films, facilitating stable color reproduction and achieving color presentation while maintaining a certain light transmittance. The roughened structure on the cover glass facing the color interference film layer increases surface micro-undulations, enhancing the mechanical interlocking between the color interference film layer and the cover glass, thereby improving interfacial adhesion and reducing the probability of local peeling or displacement of the film layer during use. Simultaneously, the scattering modulation effect of this roughened structure reduces specular reflection intensity at specific incident angles, reducing the likelihood of color shift caused by viewing angle changes and improving the uniformity of incident light distribution on the photovoltaic cell surface. The interference host layer, formed by alternating first and second films, achieves control over different wavelengths of light through refractive index differences, facilitating a relative balance between color expression and light energy utilization. This reduces the probability of decreased power generation performance due to shading or absorption, and the layered structure helps reduce interfacial stress concentration, positively contributing to extending the film layer's lifespan. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the building-integrated photovoltaic (BIPV) module provided in the embodiments of this application; Figure 2 This is a front view of the building-integrated photovoltaic (BIPV) module provided in the embodiments of this application; Figure 3 This is a cross-sectional view of the photovoltaic structure layer provided in the embodiments of this application; Figure 4 This is a schematic diagram of the cover glass structure provided in an embodiment of this application; Figure 5 This is a schematic diagram of a portion of the structure of the interference host layer provided in an embodiment of this application; Figure 6 This is a perspective view of the building-integrated photovoltaic (BIPV) module provided in the embodiments of this application; Figure 7 This is a schematic flowchart of the method for preparing a building-integrated photovoltaic (BIPV) module according to an embodiment of this application; Figure 8 This is another schematic diagram of the process for preparing the building-integrated photovoltaic (BIPV) component provided in the embodiments of this application.

[0018] Explanation of key figure labels: 10. Building-integrated photovoltaic (BIPV) module; 111. Interference main layer; 1111. First film layer; 1112. Second film layer; 112. Surface protective layer; 12. Cover glass; 121. Rough structure; 1211. Groove structure; 1212. Raised structure; 13. Photovoltaic cell; 14. First encapsulating film; 15. Second encapsulating film; 16. Back glass; 171. Frame; 1711. Installation space; 172. Junction box. Detailed Implementation

[0019] In related technologies, colored BIPV modules mainly fall into two categories: one type involves applying colored pigments or thin films to the surface of the photovoltaic module, achieving color through shading or selective transmission. However, this method significantly impacts the utilization of incident light, leading to a decrease in power generation performance, typically only 60%-80% of that of standard black photovoltaic modules, failing to balance aesthetics and power generation performance. The other type uses body-tinted glass as a cover, which presents color by absorbing different wavelengths of light. However, it exhibits strong overall light absorption, resulting in even lower power generation efficiency (below 70%), further affecting power generation performance. It also suffers from limited color representation and color shift issues under changing viewing angles. Furthermore, in applications such as historical preservation buildings and urban landscape architecture, the colors of colored BIPV modules often clash with the original architectural style, making it difficult to balance color matching and power generation performance, thus limiting their application. These problems primarily stem from relying on light absorption or shading methods to achieve color representation, making it difficult to strike a balance between light transmission characteristics and color stability.

[0020] Therefore, this application provides a building-integrated photovoltaic (BIPV) module and its manufacturing method to solve the problems in related technologies.

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] See Figures 3 to 8 As shown in the figure, this application provides a colored building-integrated photovoltaic (BIPV) module 10, which includes: a colored interference film layer, a cover glass 12, and photovoltaic cells 13 stacked sequentially; the side of the cover glass 12 facing the colored interference film layer has a rough structure 121; the colored interference film layer includes an interference body layer 111, the interference body layer 111 includes a plurality of first film layers 1111 and a plurality of second film layers 1112, the refractive index of the first film layer 1111 is greater than the refractive index of the second film layer 1112; the plurality of first film layers 1111 and the plurality of second film layers 1112 are alternately arranged along the stacking direction, wherein a second film layer 1112 is between two adjacent first film layers 1111, and a first film layer 1111 is between two adjacent second film layers 1112.

[0023] This application replaces the colored pigments or colored thin films in related technologies with the setting of a colored interference film layer, so that the incident light undergoes selective interference and reflection between multiple first film layers 1111 and multiple second film layers 1112, which is conducive to forming a stable color performance, achieving color presentation while maintaining a certain light transmittance ratio, and also achieving low power generation loss. The rough structure 121 on the side of the cover glass 12 facing the colored interference film layer increases the surface micro-undulations, which helps to enhance the mechanical interlocking between the colored interference film layer and the cover glass 12, thereby improving the interface adhesion and reducing the probability of local peeling or displacement of the film layer during use. At the same time, the scattering modulation effect of the rough structure 121 on the incident light can reduce the specular reflection intensity at a specific incident angle, which helps to reduce the possibility of color shift caused by changes in viewing angle, and helps to improve the uniformity of incident light distribution on the surface of the photovoltaic cell 13.

[0024] The interference host layer 111, formed by alternating multiple first film layers 1111 and multiple second film layers 1112, can control light of different wavelengths through the difference in refractive index. This helps to achieve a relative balance between color expression and light energy utilization, thereby reducing the probability of power generation performance degradation due to shading or absorption. Furthermore, this stacked structure helps to reduce interface stress concentration, which has a positive effect on extending the service life of the film layers.

[0025] It is understood that there may be one or more second membrane layers 1112 between two adjacent first membrane layers 1111, and there may be one or more first membrane layers 1111 between two adjacent second membrane layers 1112. The specific configuration can be set as needed, and this application does not impose any restrictions.

[0026] See Figure 3 and Figure 6 As shown, in some embodiments, the building-integrated photovoltaic (BIPV) module 10 can be a plate-like structure; the BIPV module 10 may also include a first encapsulating film 14, a second encapsulating film 15, and a backsheet glass 16. The color interference film layer, cover glass 12, first encapsulating film 14, photovoltaic cells 13, second encapsulating film 15, and backsheet glass 16 are sequentially stacked, with the photovoltaic cells 13 located between the first encapsulating film 14 and the second encapsulating film 15. This facilitates the formation of a double-sided encapsulation structure for the cells, thereby reducing the probability of moisture and external environmental intrusion and minimizing the impact of mechanical stress on the cells. The color interference film layer, cover glass 12, first encapsulating film 14, photovoltaic cells 13, second encapsulating film 15, and backsheet glass 16 form a photovoltaic structural layer.

[0027] See Figure 3 As shown, for example, the cover glass 12 can be ultra-clear tempered glass, which helps improve light transmission characteristics, thereby reducing the probability of incident light loss during transmission and improving the light-receiving efficiency of the photovoltaic cell 13. The back glass 16 can be tempered glass, which helps provide structural support and environmental protection, reducing the possibility of external impact and moisture intrusion.

[0028] See Figure 3As shown, in some embodiments, the thickness of the cover glass 12 is 3.2mm to 5mm, for example, 3.2mm, 4mm, or 5mm. The thickness of the first encapsulating film 14 is 0.1mm to 0.8mm, for example, 0.1mm, 0.2mm, 0.45mm, 0.6mm, or 0.75mm, and its material is ethylene-vinyl acetate copolymer (EVA) or polyvinyl butyral resin (PVB). The thickness of the second encapsulating film 15 is 0.1mm to 0.8mm, for example, 0.1mm, 0.2mm, 0.45mm, 0.6mm, or 0.75mm, and its material is ethylene-vinyl acetate copolymer (EVA) or polyvinyl butyral resin (PVB). The photovoltaic cell 13 is a cadmium telluride cell; the thickness of the backsheet glass 16 is 2mm to 4mm, for example, 2mm, 3mm, or 4mm. The aforementioned thickness range and parameter combination helps to achieve a balance between structural strength and light transmission characteristics, thereby reducing the probability of light loss during incident light transmission and improving light reception efficiency. At the same time, different thickness configurations are conducive to adapting to various application scenarios, reducing the impact of external loads, and extending service life to a certain extent, while also taking into account the convenience of installation and maintenance.

[0029] It is understandable that the photovoltaic cell 13 is not limited to cadmium telluride cells. The photovoltaic cell 13 can also be made of crystalline silicon cells (including monocrystalline silicon and polycrystalline silicon) or copper indium gallium selenide (CIGS) cells.

[0030] See Figure 4 As shown, in some embodiments, the rough structure 121 can be corrugated. The rough structure 121 includes multiple groove structures 1211 and multiple protrusion structures 1212, which are alternately arranged along the surface direction of the cover glass 12. Along the direction perpendicular to the surface of the cover glass 12, the distance between the bottom of the groove structure 1211 and the top of the protrusion structure 1212 is 0.5μm to 2μm; the distance between the bottoms of two adjacent groove structures 1211 along the surface direction of the cover glass 12 is 2μm to 5μm. This is beneficial for achieving color rendering while also considering light transmission characteristics, thereby reducing the probability of light energy loss due to absorption during utilization; it also helps to reduce color shift caused by changes in viewing angle, improving overall color stability.

[0031] See Figure 4 As shown, for example, the distance h1 between the bottom of the groove structure 1211 and the top of the protrusion structure 1212 can be 0.5μm, 1μm, 1.5μm or 2μm; the distance d1 between the bottoms of two adjacent groove structures 1211 along the surface direction of the cover glass 12 can be 2μm, 2.5μm, 3μm, 4μm or 5μm.

[0032] See Figure 4 As shown, the direction perpendicular to the surface of the cover glass 12 can be the thickness direction of the cover glass 12, while the surface direction of the cover glass 12 is perpendicular to the thickness direction of the cover glass 12. The rough structure 121 can be a micro / nano-scale surface undulation structure; the surface undulation structure includes a groove structure 1211 and a protrusion structure 1212. The groove structure 1211 can refer to a groove, the length of which can extend in a straight line or a curve. The protrusion structure 1212 can refer to a protrusion, the length of which can extend in a straight line or a curve. The length extension direction of the groove structure 1211 and the length extension direction of the protrusion structure 1212 are arranged parallel to each other.

[0033] It should be noted that the cross-section of the groove structure 1211 can be arc-shaped, while the protrusion structure 1212 can be the portion between two adjacent groove structures 1211 after the groove structure 1211 is formed on the surface of the flat cover glass 12. The top of the protrusion structure 1212 can be flat.

[0034] It is understood that the surface of the cover glass 12 can have two directions, such as the X direction and the Y direction, with the X direction perpendicular to the Y direction; multiple groove structures 1211 can be distributed along the X direction, and multiple protrusion structures 1212 can be distributed along the X direction, with their length extension direction being the Y direction. The X and Y directions are perpendicular to the thickness direction of the cover glass 12; the thickness direction of the cover glass 12 is defined as the Z direction.

[0035] For surface undulation structures, laser etching can be used to form them. This is beneficial for forming microstructures with relatively regular boundaries and can control dimensional deviations within the micrometer range, thereby reducing the impact on the uniformity of color interference film deposition.

[0036] See Figure 5 As shown, in some embodiments, the refractive index of the first film layer 1111 is 1.9~2.1; the refractive index of the second film layer 1112 is 1.45~1.47; the material of the first film layer 1111 includes one or more of TiO2 and SiNx; the material of the second film layer 1112 includes SiO2. This facilitates the formation of a stable refractive index difference at the film layer interface, thereby enabling the incident light to produce an interference effect at the interface and achieve color rendering, while also taking into account the light transmission characteristics, reducing the probability of light energy loss due to absorption during utilization; this material combination can also improve the environmental stability of the film layer, reduce the possibility of performance fluctuations, and extend the service life to a certain extent.

[0037] See Figure 5As shown, for example, the refractive index of the first film layer 1111 can be 1.9, 1.95, 2.0, 2.05, or 2.1; the refractive index of the second film layer 1112 can be 1.45, 1.46, or 1.47. When the material of the first film layer 1111 includes SiNx, SiNx can be silicon nitride with different stoichiometric ratios, such as Si3N4 or silicon nitride (SixNy, a combination of ratios where x > y).

[0038] See Figure 5 As shown, in some embodiments, both the first film layer 1111 and the second film layer 1112 are formed by a sputtering process, for example, by magnetron sputtering under vacuum conditions with a vacuum degree of 10. -5 The Pa level, for example, can be 5 × 10 -5 Pa or 8×10 -5 Pa, thus avoiding the introduction of impurities into the membrane layer and ensuring the purity of the membrane layer.

[0039] The sputtering power for fabricating the first film layer 1111 is 120W~150W, for example, 120W, 130W, 140W, or 150W. The sputtering power for fabricating the second film layer 1112 is 80W~100W, for example, 80W, 85W, 90W, or 95W. During the fabrication of the first film layer 1111 and the second film layer 1112, the deposition rate is controlled at 0.3nm / s~0.5nm / s, for example, 0.30nm / s, 0.35nm / s, 0.40nm / s, 0.45nm / s, or 0.5nm / s, ensuring that the optical thickness error of each layer is less than or equal to ±1%. These process parameter settings facilitate obtaining a film structure with uniform composition and controllable thickness, thereby reducing the probability of film thickness deviation affecting interference effects and improving the consistency of the film's optical performance.

[0040] See Figure 3 and Figure 5 As shown, in some embodiments, the sum of the number of multiple first film layers 1111 and multiple second film layers 1112 is 12 to 18; the thickness of the interference host layer 111 is 500 nm to 1000 nm. This facilitates the formation of a stable multiple interference structure between the film layers, thereby achieving the desired color presentation while maintaining light transmission characteristics. It can reduce the probability of optical performance fluctuations caused by insufficient or excessive film layers. At the same time, this thickness range helps to reduce stress accumulation within the film layers, reducing the possibility of cracking or peeling, and extending the service life to a certain extent, while also ensuring the stability of later maintenance. In addition, by precisely controlling the thickness and refractive index of each film layer, the interference host layer 111 can produce constructive interference with specific visible light wavelengths, reflecting saturated colors, while maintaining high transmittance for the photovoltaic effective spectrum (near-infrared and long-wave red light).

[0041] See Figure 3 and Figure 5 As shown, for example, the sum of the number of multiple first film layers 1111 and multiple second film layers 1112 can be 12, 14, 16, or 18; while the total thickness of the interference host layer 111 can be 500 nm, 600 nm, 700 nm, 750 nm, 800 nm, 900 nm, or 1000 nm. This facilitates the formation of a multi-interference control structure at the film layer interface, achieving the desired color presentation while also considering light transmission characteristics. Multiple first film layers 1111 and multiple second film layers 1112 can constitute an alternating stacked film system structure based on an optical thickness design of λ / 4, thereby enhancing the controllability and stability of the interference effect. It should be noted that the single-layer thickness of the first film layer 1111 and the second film layer 1112 can be set according to the target reflection wavelength and refractive index difference. For example, by adjusting the optical thickness of each film layer, interference conditions in different visible light bands can be met, thereby achieving different structural color effects.

[0042] By controlling the thickness and refractive index of each film layer through the aforementioned structure, the colored interference film layer can generate constructive interference with specific visible light bands, thereby reflecting the corresponding structural colors, while maintaining high transmittance for near-infrared and long-wavelength red light within the effective photovoltaic spectrum. For example, by controlling the film layer thickness, the interference film layer can generate constructive interference with the short-wavelength blue light band (450nm~490nm), thereby reflecting a blue effect; or by adjusting the film layer thickness, the interference film layer can generate constructive interference with the long-wavelength red light band (620nm~750nm), thereby reflecting a red effect. This allows the photovoltaic building-integrated module 10 provided in this application embodiment to achieve structural color presentation without relying on the colored pigments or colored films mentioned in related technologies, while reducing the probability of impacting the utilization of the effective photovoltaic spectrum, and facilitating the consistency between power generation performance and appearance.

[0043] See Figure 2 , Figure 3 and Figure 4 As shown, in some embodiments, the color interference film layer further includes a surface protective layer 112, with the interference main layer 111 located between the surface protective layer 112 and the cover glass 12. This helps to isolate and protect the interference main layer 111, reducing the probability of external environmental influence on its structural stability, thereby helping to maintain the long-term stability of the interference effect. At the same time, this interlayer arrangement helps to reduce the impact of surface wear or contamination on optical performance and extends the service life of the component to a certain extent, while also taking into account the convenience of later cleaning and maintenance.

[0044] See Figure 3 and Figure 6As shown, for example, the thickness of the surface protective layer 112 is 70nm~100nm, such as 70nm, 80nm, 85nm, 90nm or 100nm; and the material of the surface protective layer 112 includes SiO2, which can improve the weather resistance, wear resistance and corrosion resistance of the interference host layer 111, avoid film aging and peeling, and ensure long-term stable use of the component.

[0045] See Figure 1 As shown, in some embodiments, the building-integrated photovoltaic (BIPV) module 10 further includes an auxiliary structural module disposed around the photovoltaic structural layer, so that the BIPV module 10 can be adapted to the building facade installation requirements.

[0046] See Figure 3 and Figure 6 As shown, exemplarily, the auxiliary structure module includes a frame 171. Multiple frames 171 can be arranged circumferentially around the photovoltaic structure layer, and the frames 171 are fixedly connected to the photovoltaic structure layer. A sealing strip can be provided between the frame 171 and the outer surface of the photovoltaic structure layer to achieve sealing between the frame 171 and the photovoltaic structure layer. An installation space 1711 can be provided at the connection between adjacent frames 171. A junction box 172 is disposed in the installation space 1711 and is electrically connected to the photovoltaic cell 13 via a busbar. Sealant can be applied between the junction box 172 and the installation space 1711, and potting compound (e.g., two-component silicone) can be filled into the installation space 1711 to achieve sealed and concealed installation of the junction box 172, avoiding impact on the building facade aesthetics, while improving the waterproof performance of the module and reducing the risk of leakage. The frame 171 can be made of aluminum alloy or stainless steel.

[0047] See Figure 7 As shown in the embodiments of this application, a method for preparing a building-integrated photovoltaic (BIPV) module 10 is also provided, which is used to prepare the BIPV module 10 provided in any of the above embodiments. The method for preparing the BIPV module 10 includes some or all of the following steps.

[0048] Step S10: A rough structure 121 is machined on one surface of the cover glass 12.

[0049] Step S20: A colored interference film is formed on the surface of the cover glass 12 with a rough structure 121, wherein the color includes an interference main layer 111, the interference main layer 111 includes a plurality of first film layers 1111 and a plurality of second film layers 1112 alternately stacked, and the refractive index of the first film layer 1111 is greater than the refractive index of the second film layer 1112.

[0050] Step S30: Assemble the composite structure formed by the cover glass 12 and the colored interference film layer together with the photovoltaic cell 13.

[0051] The method for preparing the above-mentioned building-integrated photovoltaic (BIPV) module 10 has the same technical effects as the BIPV module 10 provided in the foregoing embodiments, and will not be repeated here.

[0052] In some embodiments, for step S10, the method of processing a rough structure 121 on a surface of the cover glass 12 includes: The surface of the cover glass 12 is processed by etching to form a plurality of groove structures 1211 and a plurality of protrusion structures 1212 alternately arranged along the surface direction of the cover glass 12. The plurality of groove structures 1211 and the plurality of protrusion structures 1212 are alternately arranged along a first direction, for example: one groove structure 1211, one protrusion structure 1212, one groove structure 1211, one protrusion structure 1212, and so on, until etching is complete; the length extension direction of the groove structure 1211 and the length extension direction of the protrusion structure 1212 can be a second direction, and the first direction and the second direction are perpendicular to each other; the first direction can be the X direction, and the second direction can be any direction. The first direction and the second direction are respectively perpendicular to the thickness direction of the cover glass 12.

[0053] The etching process can be laser etching; in the thickness direction of the cover glass 12, the distance between the bottom of the groove structure 1211 and the top of the protrusion structure 1212 is 0.5μm~2μm; the distance between the bottoms of two adjacent groove structures 1211 along the surface direction of the cover glass 12 is 2μm~5μm.

[0054] In some embodiments, for step S20, the method of forming a color interference film layer on the surface of the cover glass 12 having a rough structure 121 includes: See Figure 8 As shown, in step S21, a first film layer 1111 and a second film layer 1112 are formed on the surface of the cover glass 12 with a rough structure 121 using a sputtering process. The sum of the number of multiple first film layers 1111 and multiple second film layers 1112 is 12 to 18, and the thickness of the interference host layer 111 is 500 nm to 1000 nm. The multiple first film layers 1111 and multiple second film layers 1112 are stacked alternately along the thickness direction of the cover glass 12, for example, one first film layer 1111, one second film layer 1112, one first film layer 1111, and one second film layer 1112 are arranged alternately until the target number of interference host layers 111 is formed.

[0055] For example, magnetron sputtering can be used to fabricate the first film layer 1111 and the second film layer 1112. The second film layer 1112 of the interference host layer 111 can be in direct contact with the cover glass 12, which is beneficial to forming a gradual transition of refractive index between the cover glass 12 and the film layer, thereby reducing interface reflection loss.

[0056] It should be noted that in some other possible embodiments, the first film layer 1111 of the interference host layer 111 can also be in direct contact with the cover glass 12, thereby adjusting the structure of the film system initiation layer according to process requirements or optical design to achieve different interference control effects.

[0057] In some embodiments, in step S21, the refractive index of the first film layer 1111 is 1.9~2.1; the refractive index of the second film layer 1112 is 1.45~1.47; the material of the first film layer 1111 includes one or more of TiO2 and SiNx; the material of the second film layer 1112 includes SiO2. When the material of the first film layer 1111 includes SiNx, SiNx can be silicon nitride with different stoichiometric ratios, such as Si3N4 or silicon-rich silicon nitride (SixNy, a combination of x>y ratios).

[0058] In some embodiments, in step S21, a first film layer 1111 and a second film layer 1112 are prepared by magnetron sputtering under vacuum conditions, wherein the vacuum degree is 10. -5 The Pa level, for example, can be 5 × 10 -5 Pa or 8×10 -5 Pa. The sputtering power for preparing the first film layer 1111 is 120W~150W. The sputtering power for preparing the second film layer 1112 is 80W~100W. The deposition rate is controlled at 0.3nm / s~0.5nm / s when preparing the first film layer 1111 and the second film layer 1112.

[0059] In some embodiments, after step S20, i.e. after forming a colored interference film layer on the surface of the cover glass 12 having a rough structure 121, the method for preparing the building-integrated photovoltaic module 10 further includes: See Figure 8As shown, in step S22, a surface protective layer 112 is formed on the side of the interference host layer 111 away from the cover glass 12 using a deposition process, so that the surface protective layer 112 and the interference host layer 111 form a color interference film. The thickness of the surface protective layer 112 is 70nm~100nm, which is beneficial for covering and protecting the interference host layer 111, thereby reducing the probability of damage to the film caused by external environmental factors and helping to maintain its optical performance stability. At the same time, this thickness range helps to reduce the impact on the interference effect while providing protection, avoiding the generation of additional optical deviations, and extending the service life of the component to a certain extent, while also taking into account the convenience of surface cleaning and maintenance. For example, the thickness of the surface protective layer 112 is 70nm~100nm, such as 70nm, 80nm, 85nm, 90nm, or 100nm; and the material of the surface protective layer 112 includes SiO2. The surface protective layer 112 can also be prepared by magnetron sputtering under vacuum conditions.

[0060] In some embodiments, before step S30, that is, before assembling the composite structure formed by the cover glass 12 and the color interference film layer with the photovoltaic cell 13, the method for preparing the building-integrated photovoltaic module 10 further includes: See Figure 8 As shown, in step S23, the composite structure formed by the cover glass 12 and the color interference film is annealed at a first temperature for a first set time, wherein the first temperature is 200℃~220℃ and the first set time is 1.5h~2.5h. This helps to release the internal stress generated during the film deposition process, promotes the stability of the film structure, and thus reduces the probability of cracking or peeling during subsequent assembly and use, which is conducive to achieving a film adhesion level of 5B. At the same time, this annealing condition helps to improve the bonding stability between the film and the cover glass 12, reduce the impact of interface defects on optical performance, and extend the service life of the component to a certain extent, while also taking into account the reliability during later maintenance.

[0061] For example, the first temperature is 200°C, 210°C, or 220°C, and the first set time is 1.5h, 2h, or 2.5h, where h represents hours.

[0062] In some embodiments, for step S30, the method of assembling the composite structure formed by the cover glass 12 and the color interference film layer together with the photovoltaic cell 13 includes: See Figure 8As shown, in step S31, the colored interference film layer, cover glass 12, first encapsulating film 14, photovoltaic cell 13, second encapsulating film 15, and backplane glass 16 are sequentially stacked and then hot-pressed to form a photovoltaic structure layer. The hot-pressing temperature is 100℃~150℃, for example, 100℃, 110℃, 130℃, 145℃, or 150℃; the pressure is 0.2MPa~0.4MPa, for example, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, or 0.4MPa; and the hot-pressing time is 20min~30min, for example, 20min, 22min, 25min, 28min, or 30min. This facilitates full adhesion between the layers and eliminates interface bubbles, thereby reducing the possibility of interlayer delamination or voids and improving the overall compactness and stability of the encapsulation structure.

[0063] In some embodiments, after step S30, i.e. after assembling the composite structure formed by the cover glass 12 and the color interference film layer with the photovoltaic cell 13, the method for preparing the building-integrated photovoltaic module 10 further includes: See Figure 8 As shown, in step S40, the photovoltaic structure layer is assembled with the frame 171, and sealant is applied to the busbar outlet of the photovoltaic structure layer. The junction box 172 is fixed at the reserved installation space 1711 and the electrical connection is completed. After filling with potting compound, it is cured and shaped to obtain a colored building-integrated photovoltaic module 10.

[0064] The following detailed description of the building-integrated photovoltaic (BIPV) module 10 and its preparation method, with reference to specific embodiments, should not be construed as limiting the scope of protection of this application.

[0065] Example 1: Blue photovoltaic building-integrated module and its preparation method The method for preparing the blue building-integrated photovoltaic module 10 includes: A rough structure 121 is formed on the surface of the cover glass 12 using a laser etching process, forming an array of alternating protrusions 1212 and grooves 1211. The distance between the bottom of the groove structure 1211 and the top of the protrusion 1212 is 1 μm; the distance between the bottoms of two adjacent groove structures 1211 along the surface direction of the cover glass 12 is 3 μm.

[0066] Magnetron sputtering process at a vacuum level of 10 -5Under Pa conditions, a first film layer 1111 and a second film layer 1112 are alternately deposited. The first film layer 1111 is made of TiO2 with a refractive index of 2.05, and the second film layer 1112 is made of SiO2 with a refractive index of 1.46. The total number of interference host layers 111 is 16, and the total thickness of the interference host layers 111 is 800 nm. Multiple first film layers 1111 and multiple second film layers 1112 can form an alternating stacked film structure based on an optical thickness design of λ / 4. The sputtering power for preparing the first film layer 1111 is 140 W, and the sputtering power for preparing the second film layer 1112 is 90 W, with a deposition rate of 0.4 nm / s. In this way, the interference host layer 111 is designed to produce constructive interference in the 450 nm to 490 nm blue light band, thereby reflecting a blue structural color.

[0067] A surface protective layer 112 is deposited on the side of the interference host layer 111 away from the cover glass 12, wherein the material of the surface protective layer is SiO2 and the thickness of the surface protective layer is 80nm.

[0068] The composite structure formed by the cover glass 12 and the colored interference film was annealed at 220°C for 2 hours to release internal stress.

[0069] The colored interference film, cover glass 12, first encapsulating film 14, photovoltaic cell 13, second encapsulating film 15 and back glass 16 are sequentially stacked and then hot-pressed to form a photovoltaic structure layer. The hot-pressing temperature is 150℃, the pressure is 0.3MPa and the time is 20min.

[0070] Finally, by assembling the photovoltaic structure layer with the frame 171 and completing the encapsulation and electrical connection of the junction box 172, a blue building-integrated photovoltaic module 10 is obtained. The cover glass 12 of the blue building-integrated photovoltaic module 10 is made of ultra-white tempered glass with a thickness of 4mm. The first encapsulation film 14 and the second encapsulation film 15 are both made of ethylene-vinyl acetate copolymer (EVA). The photovoltaic cells 13 are made of cadmium telluride cells. The back glass 16 is made of tempered glass with a thickness of 3mm. The frame 171 is an aluminum alloy frame 171.

[0071] Tests showed that the blue building-integrated photovoltaic module 10 achieved a power generation efficiency of 96% compared to cadmium telluride modules under the same power generation conditions, with a light transmittance of 92%. The blue hue did not show significant shift when the viewing angle varied from 0° to 60°. Weathering tests showed that the film layer did not peel or crack after 2000 hours of cycling at -20°C to 60°C, with minimal color decay, adhesion reaching 5B level, and waterproof performance meeting IP67 standards.

[0072] Example 2: Red Building Integrated Photovoltaic Module 10 and its Preparation Method The preparation method of the red photovoltaic building integrated module 10 includes: A rough structure 121 is formed on the surface of the cover glass 12 using a laser etching process, forming an array of alternating protrusions 1212 and grooves 1211. The distance between the bottom of the groove structure 1211 and the top of the protrusion 1212 is 1.5 μm; the distance between the bottoms of two adjacent groove structures 1211 along the surface direction of the cover glass 12 is 4 μm.

[0073] Magnetron sputtering process at a vacuum level of 10 -5 Under Pa conditions, a first film layer 1111 and a second film layer 1112 are alternately deposited. The first film layer 1111 is made of SiNx with a refractive index of 1.95, and the second film layer 1112 is made of SiO2 with a refractive index of 1.46. The total number of interference host layers 111 is 14, and the total thickness of the interference host layers 111 is 700 nm. The sputtering power for preparing the first film layer 1111 is 130 W, and the sputtering power for preparing the second film layer 1112 is 85 W, with a deposition rate of 0.35 nm / s. The interference host layer 111 is designed to produce constructive interference in the 620 nm–750 nm red light band, thereby reflecting a red structural color.

[0074] A surface protective layer 112 is deposited on the side of the interference host layer 111 away from the cover glass 12, wherein the surface protective layer 112 is made of SiO2 and has a thickness of 80nm.

[0075] The composite structure formed by the cover glass 12 and the colored interference film was annealed at 220°C for 2 hours to release internal stress.

[0076] The colored interference film, cover glass 12, first encapsulating film 14, photovoltaic cell 13, second encapsulating film 15 and back glass 16 are sequentially stacked and then hot-pressed to form a photovoltaic structure layer. The hot-pressing temperature is 145℃, the pressure is 0.35MPa and the time is 25min, thereby forming the photovoltaic structure layer.

[0077] Finally, by assembling the photovoltaic structure layer with the frame 171 and completing the encapsulation and electrical connection of the junction box 172, a red building-integrated photovoltaic module 10 is obtained. The cover glass 12 of the red building-integrated photovoltaic module 10 is made of 6mm thick ultra-clear tempered glass. The first encapsulation film 14 and the second encapsulation film 15 are both made of polyvinyl butyral resin (PVB) to improve impact resistance. The photovoltaic cells 13 are made of cadmium telluride cells. The back panel glass 16 is made of 3mm thick tempered glass. The frame 171 is an aluminum alloy frame 171.

[0078] Testing revealed that the red building-integrated photovoltaic (BIPV) module 10 exhibits a power generation efficiency of 94% and a light transmittance of 91% compared to the cadmium telluride module under the same power generation conditions. The red hue remains relatively stable when the viewing angle varies from 0° to 60°. Its weather resistance and abrasion resistance are comparable to those of Example 1. This red BIPV module 10 demonstrates good color coordination in building facade and roof applications, making it suitable for applications requiring high aesthetic consistency, such as historical preservation buildings.

[0079] In summary, the photovoltaic building integrated module 10 provided in this application achieves color presentation through the structural design of the color interference film layer, and takes into account the photovoltaic power generation requirements while ensuring the appearance effect; through the coordinated control of the parameters of the multilayer film system and the surface morphology of the cover glass 12, it is beneficial to reduce the fluctuation of color with the viewing angle, and the color can be adjusted according to different design requirements to adapt to various building facade application scenarios.

[0080] Furthermore, the combined arrangement of the interference main layer 111, the surface protective layer 112, and the annealing treatment helps to improve the stability of the film structure and its environmental adaptability, and reduces the impact of external factors on the film performance. Combined with the double-glass structure and encapsulation system design, it helps to improve the overall reliability of the module and extend its service life to a certain extent. At the same time, this preparation method has good compatibility with existing photovoltaic module processes, which facilitates large-scale production and helps to balance consistency and feasibility in engineering applications.

[0081] It should be understood that, in the embodiments of this application, unless otherwise expressly specified and limited, the terms "connection," "fixed connection," "contact," etc., should be interpreted broadly. Those skilled in the art can understand the specific meanings of the various terms in the embodiments of this application according to the specific circumstances.

[0082] For example, the "connection" can be a fixed connection, a rotating connection, a flexible connection, a sliding connection, a one-piece molding, an electrical connection, a contact connection, or other connection methods; it can be a direct connection, or an indirect connection through an intermediate medium, or a connection within two components or an interaction between two components.

[0083] For example, a "fixed connection" can be a component that can be directly or indirectly fixedly connected to another component; a fixed connection can include mechanical connection, welding, bonding or integral molding, etc., wherein mechanical connection can include riveting, bolting, threaded connection, keying, snap-fit ​​connection, locking connection, plugging, etc., and bonding can include adhesive bonding and solvent bonding, etc.

[0084] It should also be understood that the “parallel” or “perpendicular” described in the embodiments of this application can be understood as “approximately parallel” or “approximately perpendicular”.

[0085] It should also be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0086] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0087] It should also be understood that the terms “length,” “width,” “up,” “down,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship (if any) based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0088] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims. In conclusion, the above are merely preferred embodiments of the technical solution of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A building-integrated photovoltaic (BIPV) module, characterized in that, include: The colored interference film, cover glass, and photovoltaic cells are stacked in sequence. The side of the cover glass facing the colored interference film has a rough structure; The color interference film includes an interference host layer, which includes multiple first films and multiple second films, wherein the refractive index of the first films is greater than the refractive index of the second films. Multiple first film layers and multiple second film layers are alternately arranged along the stacking direction, wherein a second film layer is located between two adjacent first film layers, and a first film layer is located between two adjacent second film layers.

2. The building-integrated photovoltaic (BIPV) module as described in claim 1, characterized in that, The rough structure includes multiple groove structures and multiple protrusion structures, which are alternately arranged along the surface direction of the cover glass. Along a direction perpendicular to the surface of the cover glass, the distance between the bottom of the groove structure and the top of the protrusion structure is 0.5μm~2μm; The distance between the bottoms of two adjacent groove structures along the surface of the cover glass is 2μm to 5μm.

3. The building-integrated photovoltaic (BIPV) module as described in claim 1 or 2, characterized in that, The colored interference film layer also includes a surface protective layer, and the interference body layer is located between the surface protective layer and the cover glass.

4. The building-integrated photovoltaic (BIPV) module as described in claim 1 or 2, characterized in that, The refractive index of the first film layer is 1.9~2.1; the refractive index of the second film layer is 1.45~1.47; The material of the first film layer includes one or more of TiO2 and SiNx; the material of the second film layer includes SiO2.

5. The building-integrated photovoltaic (BIPV) module as described in claim 1 or 2, characterized in that, The sum of the number of the plurality of first film layers and the plurality of second film layers is 12 to 18; the thickness of the interference host layer is 500 nm to 1000 nm.

6. A method for preparing a building-integrated photovoltaic (BIPV) module, used to prepare a BIPV module as described in any one of claims 1-5, characterized in that, include: A rough texture is machined onto one surface of the cover glass; A colored interference film is formed on the surface of the cover glass with a rough structure, wherein the color includes an interference main layer, the interference main layer includes a plurality of first film layers and a plurality of second film layers that are alternately stacked, and the refractive index of the first film layer is greater than the refractive index of the second film layer; The composite structure formed by the cover glass and the colored interference film is assembled with the photovoltaic cell.

7. The method for preparing a building-integrated photovoltaic (BIPV) module as described in claim 6, characterized in that, The process of creating a rough structure on one surface of the cover glass includes: The surface of the cover glass is processed by etching to form multiple groove structures and multiple protrusion structures that are alternately arranged along the surface direction of the cover glass.

8. The method for preparing a building-integrated photovoltaic (BIPV) module as described in claim 6 or 7, characterized in that, The process of forming a colored interference film layer on the surface of the cover glass with a rough structure includes: A first film layer and a second film layer are formed on the surface of the cover glass with a rough structure by a sputtering process, wherein the sum of the number of the plurality of first film layers and the plurality of second film layers is 12 to 18, and the thickness of the interference host layer is 500 nm to 1000 nm.

9. The method for preparing a building-integrated photovoltaic (BIPV) module as described in any one of claims 6-8, characterized in that, After forming a colored interference film layer on the rough-structured surface of the cover glass, the method for manufacturing a building-integrated photovoltaic module further includes: A surface protective layer is formed on the side of the interference body layer away from the cover glass using a deposition process, so that the surface protective layer and the interference body layer form the color interference film layer, wherein the thickness of the surface protective layer is 70nm~100nm.

10. The method for preparing a building-integrated photovoltaic (BIPV) module as described in claim 9, characterized in that, Before assembling the composite structure formed by the cover glass and the colored interference film layer with the photovoltaic cells, the method for preparing the building-integrated photovoltaic module further includes: The composite structure formed by the cover glass and the colored interference film is annealed at a first temperature for a first set time, wherein the first temperature is 200℃~220℃ and the first set time is 1.5h~2.5h.

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