Photovoltaic module

Abstract

The present application relates to the technical field of photovoltaics, and discloses a photovoltaic module, so as to solve the problems of significant visual differences and poor aesthetics of photovoltaic modules. The photovoltaic module comprises a cover plate, cells, and a packaging plate which are sequentially stacked from top to bottom. A passivation layer is provided on the surface of each cell on the side facing the cover plate. The refractive index of the passivation layer is greater than or equal to 1.9 and less than or equal to 2.3. The thickness of the passivation layer is greater than or equal to 50 nm and less than or equal to 100 nm. The cover plate is provided with an anti-reflection layer, and the anti-reflection layer is located on the side of the cover plate away from the cells. The thickness of the anti-reflection layer is greater than or equal to 100 nm and less than or equal to 230 nm. The refractive index of the anti-reflection layer is greater than or equal to 1.1 and less than or equal to 1.4.

Description

A photovoltaic module

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 1, 2023, with application number 2023229529910 and invention name “A back-contact photovoltaic module”, and the Chinese patent application filed with the China Patent Office on April 29, 2024, with application number 2024209230173 and invention name “A photovoltaic module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Art

[0003] Photovoltaic modules usually include a laminate, a junction box, and a frame. The laminate usually includes a cover plate, a solar cell layer, and a back plate stacked in order from top to bottom.

[0004] In existing technology, the side of the solar cell layer facing the cover plate typically has a passivation layer. Due to the presence of the passivation layer, the solar cells generally appear blue or dark blue. The photovoltaic modules made using these cells in this way have significant visual differences and are less aesthetically pleasing.

[0005] Summary of the Invention

[0006] The purpose of the present application is to provide a photovoltaic module, which is used to make the photovoltaic module visually present a more uniform color, so as to reduce the visual differences of the photovoltaic module and improve the aesthetics of the photovoltaic module.

[0007] In order to achieve the above-mentioned purpose, the present application provides a photovoltaic module. The photovoltaic module includes a cover plate, a battery cell and an encapsulation plate stacked in sequence from top to bottom. The surface of the battery cell facing the cover plate has a passivation layer. The refractive index of the passivation layer is greater than or equal to 1.9 and less than or equal to 2.3. The thickness of the passivation layer is greater than or equal to 50nm and less than or equal to 100nm. An anti-reflection layer is provided on the cover plate, and the anti-reflection layer is located on the side of the cover plate away from the battery cell. The thickness of the anti-reflection layer is greater than or equal to 100nm and less than or equal to 230nm. The refractive index of the anti-reflection layer is greater than or equal to 1.1 and less than or equal to 1.4.

[0008] Compared with the prior art, in the photovoltaic modules provided by the present application, when the passivation layer and the anti-reflection layer that meet the above-mentioned limitations are used to make the photovoltaic modules, the combined effect of the passivation layer and the anti-reflection layer makes the photovoltaic modules visually appear to be a relatively uniform dark blue or black color, which reduces the visual difference compared to the photovoltaic modules in the prior art and improves the aesthetics of the photovoltaic modules. Furthermore, since the thickness and refractive index of the passivation layer, as well as the thickness and refractive index of the anti-reflection layer, are all within a certain range of values, they are not a single absolute value. Therefore, the values ​​of the above four limiting conditions can be selected according to actual conditions. At this time, the photovoltaic modules can be adapted to different application scenarios to expand their scope of application and facilitate promotion. In addition, the use of an anti-reflection layer of the above-mentioned thickness can improve the weather resistance of the cover plate.

[0009] In one implementation, the refractive index of the passivation layer is greater than or equal to 2.0 and less than or equal to 2.2; and the refractive index of the anti-reflection layer is greater than or equal to 1.2 and less than or equal to 1.3.

[0010] In one implementation, the anti-reflection layer is a stacked structure including at least two layers.

[0011] In one implementation, the anti-reflection layer includes a first anti-reflection layer and a second anti-reflection layer stacked in sequence, and the second anti-reflection layer is located between the cover plate and the first anti-reflection layer.

[0012] When using the above technical solution, the second anti-reflection layer not only reduces the flatness of the cover plate surface and reduces the inconsistency of light reflection directions, but also reduces the color difference of the cover plate. Furthermore, the first anti-reflection layer, by utilizing its refractive index, can bring the color difference of the cover plate toward zero, thereby reducing or eliminating the color difference after the cover plate and solar cell are combined, and also improving the aesthetics of the photovoltaic module.

[0013] In one implementation, the thickness of the first anti-reflection layer is greater than the thickness of the second anti-reflection layer.

[0014] In one implementation, the thickness of the first anti-reflection layer is greater than or equal to 80 nm and less than or equal to 150 nm; the thickness of the second anti-reflection layer is greater than or equal to 50 nm and less than or equal to 100 nm.

[0015] In one implementation, the refractive index of the first anti-reflection layer is smaller than the refractive index of the second anti-reflection layer.

[0016] The above technical solution ensures the weather resistance of the cover plate and achieves an optimized coating matching value. Furthermore, the combined thickness of the first and second anti-reflection layers is relatively thick, further enhancing the weather resistance of the cover plate. Furthermore, the destructive interference between the first and second anti-reflection layers improves light transmittance and achieves broadband anti-reflection.

[0017] In one implementation, the refractive index of the first anti-reflection layer is greater than or equal to 1.1 and less than or equal to 1.3; the refractive index of the second anti-reflection layer is greater than or equal to 1.3 and less than or equal to 1.5.

[0018] In one implementation, the refractive index of the first anti-reflection layer is greater than or equal to 1.2 and less than or equal to 1.3; the refractive index of the second anti-reflection layer is greater than or equal to 1.4 and less than or equal to 1.5.

[0019] In one implementation, the porosity of the first anti-reflection layer is greater than that of the second anti-reflection layer. This ensures that the refractive index of the first anti-reflection layer is lower than that of the second anti-reflection layer, thereby ensuring the weather resistance of the cover plate and achieving an optimized coating matching value.

[0020] In one implementation, the porosity of the first anti-reflection layer is greater than or equal to 35% and less than or equal to 60%. In this case, the optical performance of the first anti-reflection layer can be ensured.

[0021] In one implementation, the porosity of the second anti-reflection layer is greater than or equal to 10% and less than or equal to 30%, thereby further improving the weather resistance of the cover plate.

[0022] In one implementation, the light transmittance of the laminate formed by the cover plate and the anti-reflection layer is greater than or equal to 90%, which is more conducive to light irradiating the cell, thereby improving the cell's utilization of visible light and the photovoltaic conversion efficiency of the photovoltaic module.

[0023] In one implementation, the passivation layer includes a first passivation layer and a second passivation layer that are stacked, and the first passivation layer is located between the cover plate and the second passivation layer.

[0024] When the above technical solution is adopted, using two film layers to control the color of the battery cell is more convenient, easier to implement, and reduces difficulty compared to using one film layer to control it.

[0025] In one implementation, one of the first and second passivation layers is an aluminum oxide passivation layer, and the other is a silicon nitride passivation layer. The aluminum oxide passivation layer has a thickness greater than or equal to 5 nm and less than or equal to 10 nm; the aluminum oxide passivation layer has a refractive index greater than or equal to 1.5 and less than or equal to 1.8. The silicon nitride passivation layer has a thickness greater than or equal to 50 nm and less than or equal to 80 nm; the silicon nitride passivation layer has a refractive index greater than or equal to 1.8 and less than or equal to 2.2.

[0026] In one implementation, the first passivation layer is an aluminum oxide passivation layer, and the second passivation layer is a silicon nitride passivation layer.

[0027] In one implementation, the anti-reflection layer includes at least one of a silicon nitride anti-reflection layer, a silicon oxide anti-reflection layer, and a titanium oxide anti-reflection layer.

[0028] In one implementation, the cell is a back-contact cell.

[0029] In one implementation, the photovoltaic module further includes a first adhesive film layer and a second adhesive film layer. The first adhesive film layer is located between the cover plate and the solar cell, and the second adhesive film layer is located between the solar cell and the encapsulation plate. The first and second adhesive film layers are used to wrap the solar cell.

[0030] In one implementation, the package board is a black organic package board or a black glazed package board, and / or the photovoltaic module is an all-black photovoltaic module.

[0031] Using this technical solution, the front of the photovoltaic module can appear completely black, creating a visually uniform color. This reduces visual variations and improves the aesthetics of the module. Furthermore, the completely black photovoltaic module improves the utilization of visible light, thereby increasing the photovoltaic module's photoelectric conversion efficiency.

[0032] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0034] FIG1 is a schematic structural diagram of a photovoltaic module according to an embodiment of the present application;

[0035] FIG2 is a schematic diagram showing the positional relationship between the battery cell and the passivation layer in an embodiment of the present application;

[0036] FIG3 is a schematic diagram showing the positional relationship between the cover plate and the anti-reflection layer in an embodiment of the present application;

[0037] FIG4 is a schematic diagram showing the relationship between incident light, a cover plate, and an anti-reflection layer in an embodiment of the present application;

[0038] FIG5 is a schematic diagram of the structure of a battery cell in an embodiment of the present application.

[0039] Figure numerals: 1-cover plate, 2-cell, 20-passivation layer, 200-first passivation layer, 2002-silicon nitride layer; 2001-silicon oxide nitride layer, 201-second passivation layer, 3-packaging plate, 4-anti-reflection layer, 40-first anti-reflection layer, 41-second anti-reflection layer, 5-first adhesive film layer, 6-second adhesive film layer. Specific embodiments

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0041] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0043] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are 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 direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0044] In order to solve the above technical problems, an embodiment of the present application provides a photovoltaic module. Referring to Figures 1 to 3, the photovoltaic module includes a cover plate 1, a cell 2 and an encapsulation plate 3 stacked in sequence from top to bottom. On the side facing the cover plate 1, the surface of the cell 2 has a passivation layer 20. The refractive index of the passivation layer 20 is greater than or equal to 1.9 and less than or equal to 2.3. For example, the refractive index of the passivation layer 20 can be 1.9, 1.93, 1.95, 1.98, 2.0, 2.05, 2.08, 2.1, 2.13, 2.16, 2.19, 2.2, 2.23, 2.25, 2.28 or 2.3, etc. Preferably, the refractive index of the passivation layer 20 is greater than or equal to 2.0 and less than or equal to 2.2. For example, the refractive index of the passivation layer 20 may be 2.0, 2.05, 2.08, 2.1, 2.13, 2.16, 2.19, or 2.2. The thickness D1 of the passivation layer 20 may be greater than or equal to 50 nm and less than or equal to 100 nm. For example, the thickness D1 of the passivation layer 20 may be 50 nm, 60 nm, 70 nm, 80 nm, 92 nm, or 100 nm. An anti-reflection layer 4 is provided on the cover plate 1, and the anti-reflection layer 4 is located on the side of the cover plate 1 away from the solar cell 2. The thickness D2 of the anti-reflection layer 4 may be greater than or equal to 100 nm and less than or equal to 230 nm. For example, the thickness D2 of the anti-reflection layer 4 may be 100 nm, 120 nm, 150 nm, 180 nm, 195 nm, 200 nm, or 230 nm. The refractive index of the anti-reflection layer 4 may be greater than or equal to 1.1 and less than or equal to 1.4. For example, the refractive index of the anti-reflection layer 4 can be 1.1, 1.12, 1.15, 1.18, 1.2, 1.21, 1.23, 1.25, 1.28, 1.3, 1.32, 1.36, 1.38, or 1.4, etc. Preferably, the refractive index of the anti-reflection layer 4 is greater than or equal to 1.2 and less than or equal to 1.3. For example, the refractive index of the anti-reflection layer 4 can be 1.2, 1.21, 1.23, 1.25, 1.28, or 1.3, etc. It should be understood that the thickness direction of the passivation layer 20 and the thickness direction of the anti-reflection layer 4 are both consistent with the direction from the cover plate 1 to the packaging plate 3.

[0045] Referring to Figures 1 to 3, in the photovoltaic modules (preferably back-contact photovoltaic modules) provided in the embodiments of the present application, when the passivation layer 20 and anti-reflection layer 4 that meet the above-mentioned limitations are used to manufacture the photovoltaic modules, the combined effect of the passivation layer 20 and the anti-reflection layer 4 makes the photovoltaic modules visually present a relatively uniform dark blue or black color, reducing visual differences compared to photovoltaic modules in the prior art and improving the aesthetics of the photovoltaic modules. Furthermore, since the thickness and refractive index of the passivation layer 20, as well as the thickness and refractive index of the anti-reflection layer 4, are all within a certain range of values, rather than a single absolute value, the values ​​of the above four limiting conditions can be selected according to actual conditions. In this case, the photovoltaic modules can be adapted to different application scenarios, thereby expanding their scope of application and facilitating promotion. For example, when the passivation layer thickness is 80nm and the refractive index is 2.0, the anti-reflection layer thickness is required to be greater than or equal to 120nm and less than or equal to 180nm, and the refractive index is greater than or equal to 1.22 and less than or equal to 1.25, so that the module has a uniform blue-black appearance. However, when the thickness of the passivation layer is 100nm and the refractive index is 2.1, the thickness of the anti-reflection layer needs to be greater than or equal to 150nm and less than or equal to 200nm, and the refractive index is greater than or equal to 1.23 and less than or equal to 1.28, and the appearance of the component is uniform blue-black.

[0046] Furthermore, using an anti-reflection layer 4 of the aforementioned thickness can improve the weather resistance of the cover plate 1. Furthermore, the surface of the cell 2 facing the cover plate 1 has a passivation layer 20. That is, the light-receiving surface of the cell 2 is provided with a passivation layer 20. This passivation layer can passivate the front electric field, for example, by including field passivation and interface passivation, to protect the front electric field.

[0047] As a possible implementation, referring to Figures 1 and 2, the passivation layer 20 comprises a stacked structure of at least two passivation layers. However, for cost and manufacturing process considerations, the passivation layer 20 preferably comprises a first passivation layer 200 and a second passivation layer 201 stacked together, with the first passivation layer 200 positioned between the cover plate 1 and the second passivation layer 201. Using two film layers to control the color of the cell 2 is more convenient, easier to implement, and less challenging than using a single film layer.

[0048] In one optional embodiment, one of the first passivation layer and the second passivation layer is an aluminum oxide passivation layer, and the other is a silicon nitride passivation layer. The thickness of the aluminum oxide passivation layer is greater than or equal to 5 nm and less than or equal to 10 nm. For example, the thickness of the aluminum oxide passivation layer can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm. The refractive index of the aluminum oxide passivation layer is greater than or equal to 1.5 and less than or equal to 1.8. For example, the refractive index of the aluminum oxide passivation layer can be 1.5, 1.55, 1.6, 1.65, 1.7, 1.75 or 1.8. The thickness of the silicon nitride passivation layer is greater than or equal to 50 nm and less than or equal to 80 nm. For example, the thickness of the silicon nitride passivation layer can be 50 nm, 52 nm, 60 nm, 66 nm, 70 nm or 80 nm. The refractive index of the silicon nitride passivation layer is greater than or equal to 1.8 and less than or equal to 2.2. For example, the refractive index of the silicon nitride passivation layer may be 1.8, 1.85, 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, or 2.2, among others.

[0049] Preferably, the first passivation layer is an aluminum oxide passivation layer, and the second passivation layer is a silicon nitride passivation layer.

[0050] As a possible implementation, as shown in FIG5 , the first passivation layer 200 preferably includes a two-layer structure, for example, an oxygen-poor silicon nitride layer 2002 (the atomic ratio of silicon and nitrogen in the silicon nitride layer 2002 is not specific and may contain a very small amount of oxygen) and an oxygen-rich silicon oxynitride layer 2001 (the atomic ratio of silicon, oxygen, and nitrogen is not specific); the thickness of the silicon nitride layer 2002 is 30 nm to 60 nm, for example, the thickness of the silicon nitride layer 2002 can be 30 nm, 35 nm, 40 nm, 45 nm, 55 nm, 60 nm, etc. The refractive index of the silicon nitride layer 2002 is 1.9 to 2.3, for example, the refractive index of the silicon nitride layer 2002 can be 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, 2.2, 2.25, or 2.3, etc. The thickness of the silicon oxynitride layer 2001 is 20 nm to 50 nm. For example, the thickness of the silicon oxynitride layer 2001 can be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc. The refractive index of the silicon oxynitride layer 2001 is 1.5 to 1.9. For example, the refractive index of the silicon oxynitride layer 2001 can be 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, or 1.9, etc.

[0051] Of course, the silicon nitride layer 2002 can be formed by one-step deposition or multiple-step deposition (ie, several layers are deposited and stacked to form the silicon nitride layer 2002 ), and the same is true for the silicon oxide nitride layer 2001 .

[0052] The anti-reflection layer may be a single layer or at least two layers. The following description takes two possible cases as examples. It should be understood that the following description is for understanding only and is not intended to be a specific limitation.

[0053] Example 1: The anti-reflection layer is a single layer, the thickness of the anti-reflection layer is greater than or equal to 105 nm and less than or equal to 135 nm, and the refractive index of the anti-reflection layer is greater than or equal to 1.1 and less than or equal to 1.4.

[0054] Example 2: The anti-reflection layer is a laminated structure comprising at least two layers. However, for cost and manufacturing process considerations, referring to FIG3 , the anti-reflection layer 4 preferably comprises a first anti-reflection layer 40 and a second anti-reflection layer 41 stacked in sequence, with the second anti-reflection layer 41 positioned between the cover plate 1 and the first anti-reflection layer 40.

[0055] When using the above technical solution, the second anti-reflection layer 41 not only reduces the surface flatness of the cover plate 1 and reduces the inconsistency of light reflection directions, but also reduces the color difference of the cover plate 1. Furthermore, the first anti-reflection layer 40, by utilizing its refractive index, can bring the color difference of the cover plate 1 toward zero, thereby reducing or eliminating the color difference after the cover plate 1 and the solar cell 2 are combined, and also improving the aesthetics of the photovoltaic module.

[0056] As a possible implementation manner, the thickness of the first anti-reflection layer is greater than the thickness of the second anti-reflection layer.

[0057] In one embodiment, the thickness of the first anti-reflection layer 40 is greater than or equal to 80 nm and less than or equal to 150 nm. For example, the thickness of the first anti-reflection layer 40 can be 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, or 150 nm. Preferably, the thickness of the first anti-reflection layer 40 is greater than or equal to 100 nm and less than or equal to 130 nm. For example, the thickness of the first anti-reflection layer 40 can be 100 nm, 110 nm, 115 nm, 120 nm, 125 nm, or 130 nm.

[0058] In one embodiment, the thickness of the second anti-reflection layer 41 is greater than or equal to 50 nm and less than or equal to 100 nm. For example, the thickness of the second anti-reflection layer 41 can be 50 nm, 55 nm, 60 nm, 70 nm, 72 nm, 76 nm, 80 nm, 85 nm, 90 nm, 95 nm, or 100 nm. Preferably, the thickness of the second anti-reflection layer 41 is greater than or equal to 70 nm and less than or equal to 90 nm. For example, the thickness of the second anti-reflection layer 41 can be 70 nm, 72 nm, 76 nm, 80 nm, 85 nm, or 90 nm.

[0059] As a possible implementation manner, the refractive index of the first anti-reflection layer is smaller than the refractive index of the second anti-reflection layer.

[0060] This ensures the weather resistance of the cover plate 1 and achieves an optimized coating matching value. Furthermore, the combined thickness of the first and second anti-reflection layers 40, 41 is relatively thick, further enhancing the weather resistance of the cover plate 1. Furthermore, the destructive interference between the first and second anti-reflection layers 40, 41 increases light transmittance, achieving broadband anti-reflection.

[0061] In one optional embodiment, the refractive index of the first anti-reflection layer 40 is greater than or equal to 1.1 and less than or equal to 1.3. For example, the refractive index of the first anti-reflection layer 40 may be 1.1, 1.15, 1.18, 1.2, 1.21, 1.23, 1.25, 1.28, or 1.3. Preferably, the refractive index of the first anti-reflection layer 40 is greater than or equal to 1.2 and less than or equal to 1.3. For example, the refractive index of the first anti-reflection layer 40 may be 1.2, 1.21, 1.23, 1.25, 1.28, or 1.3. The refractive index of the second anti-reflection layer 41 is greater than or equal to 1.3 and less than or equal to 1.5. For example, the refractive index of the second anti-reflection layer 41 may be 1.3, 1.33, 1.36, 1.39, 1.4, 1.42, 1.45, 1.46, 1.48, 1.49, or 1.5. Preferably, the refractive index of the second anti-reflection layer 41 is greater than or equal to 1.4 and less than or equal to 1.5. For example, the refractive index of the second anti-reflection layer 41 can be 1.4, 1.42, 1.45, 1.46, 1.48, 1.49 or 1.5.

[0062] The refractive index and porosity satisfy the following relationship: p 2 =(n 2 -1)(1-p)+1, where n p represents the refractive index of the porous film, n represents the refractive index of SiO2, n = 1.553, and p represents the volume percentage of pores in the film. As a possible implementation, the porosity of the first anti-reflection layer 40 is greater than the porosity of the second anti-reflection layer 41. In this case, the refractive index of the first anti-reflection layer 40 can be ensured to be lower than that of the second anti-reflection layer 41, thereby ensuring the weather resistance of the cover plate 1 and achieving an optimized coating matching value.

[0063] In one embodiment, the porosity of the first anti-reflection layer 40 is greater than or equal to 35% and less than or equal to 60%. For example, the porosity of the first anti-reflection layer 40 can be 35%, 36%, 40%, 45%, 49%, 50%, 55%, or 60%. In this case, the optical performance of the first anti-reflection layer 40 can be ensured. Preferably, the porosity of the first anti-reflection layer 40 is 49%.

[0064] In one embodiment, the porosity of the second anti-reflection layer 41 is greater than or equal to 10% and less than or equal to 30%. For example, the porosity of the second anti-reflection layer 41 can be 10%, 12%, 16%, 19%, 20%, 25%, or 30%. In this case, the weather resistance of the cover plate 1 can be further improved. Preferably, the porosity of the second anti-reflection layer 41 is 19%.

[0065] As a preferred embodiment, a double or more-layer anti-reflection layer can better adjust the total refractive index and thickness of the anti-reflection layer, which facilitates matching with the passivation layer on the solar cell to achieve the best visual effect (i.e., uniform color and no glare). For example, for a double-layer anti-reflection layer, when the first anti-reflection layer 40 has a thickness of 100nm and a refractive index of 1.25, it is necessary to set the second anti-reflection layer 41 to have a thickness greater than or equal to 80nm and less than or equal to 90nm, and a refractive index greater than or equal to 1.42 and less than or equal to 1.46, to achieve better color uniformity.

[0066] As a possible implementation, referring to Figures 1 and 3 , the light transmittance of the laminate formed by the cover plate 1 and the anti-reflection layer 4 is greater than or equal to 90%. This facilitates light from reaching the cell 2, thereby increasing the cell 2's utilization of visible light and improving the photovoltaic module's photoelectric conversion efficiency. Preferably, the light transmittance of the laminate formed by the cover plate 1 and the anti-reflection layer 4 is greater than or equal to 93%.

[0067] As a possible implementation, the anti-reflection layer includes at least one of a silicon nitride anti-reflection layer, a silicon oxide anti-reflection layer, and a titanium oxide anti-reflection layer. Exemplarily, the material of the first and second anti-reflection layers can be at least one of silicon nitride, silicon oxide, and titanium oxide.

[0068] As a possible implementation manner, the anti-reflection layer may be formed on the cover plate by a process such as sputtering.

[0069] In an optional embodiment, the cover plate may be soda glass, and the thickness may be 3.2 mm or 2.0 mm. The refractive index of the cover plate is about 1.5, and the refractive index of air is about 1.0. For example, FIG4 shows a situation where incident light (such as sunlight) passes through the first anti-reflection layer 40, the second anti-reflection layer 41 and the cover plate 1 in sequence, and the light located in the cover plate 1 is transmitted light. Since the refractive index of air is less than the refractive index of the first anti-reflection layer, less than the refractive index of the second anti-reflection layer, and less than the refractive index of the cover plate, it can be seen that the refractive index increases from the air to the cover plate, so that the refractive angle of the incident light gradually decreases and gradually tends to vertical incidence, at which time the utilization rate of light increases.

[0070] As a possible implementation method, the cell is a back-contact cell. This can achieve a front-side without grid lines and solder strips blocking the view, resulting in a more uniform color.

[0071] As a possible implementation, referring to FIG1 , the photovoltaic module further includes a first adhesive film layer 5 and a second adhesive film layer 6. The first adhesive film layer 5 is located between the cover plate 1 and the cell 2, and the second adhesive film layer 6 is located between the cell 2 and the encapsulation plate 3. The first and second adhesive film layers 5 and 6 are used to wrap the cell.

[0072] In one embodiment, the first or second adhesive film layer may be made of one of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyvinyl butyral (PVB), and ionomer. The first or second adhesive film layer may be made of the same material or different materials.

[0073] In one optional embodiment, the first film layer (or second film layer) can be a double-layer film layer or a triple-layer film layer. The first film layer (or second film layer) can have an EP structure or an EPE structure. The thickness of the first film layer (or second film layer) is greater than or equal to 0.4 mm and less than or equal to 0.6 mm. The thickness of the first film layer (or second film layer) is greater than the thickness of the soldering ribbon to ensure lamination reliability.

[0074] In one alternative embodiment, the photovoltaic module is formed into a cell string structure using multiple solder ribbons, which are only applied to the backlight side of the cell. The solder ribbons can be flat ribbons with a cross-sectional size of 0.35 mm by 0.6 mm. A bonding layer is provided on the surface of the flat ribbons, which can be a tin-lead alloy.

[0075] In an optional embodiment, the length of the above-mentioned battery cell is greater than or equal to 180 mm and less than or equal to 220 mm. For example, the length of the battery cell may be 180 mm, 185 mm, 190 mm, 195 mm, 200 mm, 205 mm, 210 mm, 215 mm or 220 mm, etc. The battery cell is a back-contact battery cell, and the thickness is greater than or equal to 100 μm and less than or equal to 180 μm. For example, the thickness of the battery cell may be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm or 180 μm, etc. The front of the back-contact battery cell is not blocked by grid lines and solder strips, and it can have a better front appearance and the best color uniformity effect.

[0076] In an optional embodiment, when the encapsulation plate is a transparent plate, the photovoltaic module is a double-glass photovoltaic module. When the encapsulation plate is a non-transparent plate, the photovoltaic module is a single-glass photovoltaic module.

[0077] As a possible implementation, the package board is a black organic package board or a black glaze package board, and / or the photovoltaic module is an all-black photovoltaic module, that is, an all-black photovoltaic module.

[0078] In this case, the front of the photovoltaic module can be made completely black, giving it a visually uniform color, reducing visual differences and improving its aesthetics. Furthermore, the completely black photovoltaic module improves the utilization of visible light, thereby increasing its photoelectric conversion efficiency.

[0079] Exemplarily, the black glaze packaging plate refers to a grid-shaped black glaze layer provided on an inorganic glass plate, wherein the black glaze layer is located between the cell and the inorganic glass plate to ensure that the front appearance of the photovoltaic module appears completely black.

[0080] In summary, the embodiments of the present application utilize optical complementarity between different visible light bands, ultimately achieving a certain equilibrium and reducing color differences between bands. Due to optical complementarity, a single-layer transmittance curve has a peak, resulting in a distinct blue appearance. A colorless layer, through two layers of refractive index adjustment, exhibits no distinct peaks and exhibits no color. See Table 1 for details.

[0081] Table 1 Visible light wavelengths of different colors and their complementary light

[0082] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0083] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A photovoltaic module, comprising: The cover plate, the battery cell and the packaging plate are stacked in sequence from top to bottom; wherein, The surface of the cell has a passivation layer on the side facing the cover plate; the refractive index of the passivation layer is greater than or equal to 1.9 and less than or equal to 2.3; the thickness of the passivation layer is greater than or equal to 50 nm and less than or equal to 100 nm; An anti-reflection layer is disposed on the cover plate, and the anti-reflection layer is located on a side of the cover plate away from the battery cell; The thickness of the anti-reflection layer is greater than or equal to 100 nm and less than or equal to 230 nm; the refractive index of the anti-reflection layer is greater than or equal to 1.1 and less than or equal to 1.

4.

2. The photovoltaic module according to claim 1, wherein: The refractive index of the passivation layer is greater than or equal to 2.0 and less than or equal to 2.2; the refractive index of the anti-reflection layer is greater than or equal to 1.2 and less than or equal to 1.

3.

3. The photovoltaic module according to claim 1, wherein: The anti-reflection layer is a stacked structure including at least two layers.

4. The photovoltaic module according to claim 3, wherein: The anti-reflection layer comprises a first anti-reflection layer and a second anti-reflection layer stacked in sequence, and the second anti-reflection layer is located between the cover plate and the first anti-reflection layer.

5. The photovoltaic module according to claim 4, wherein: The thickness of the first anti-reflection layer is greater than the thickness of the second anti-reflection layer.

6. The photovoltaic module according to claim 5, wherein: The thickness of the first anti-reflection layer is greater than or equal to 80 nm and less than or equal to 150 nm; The thickness of the second anti-reflection layer is greater than or equal to 50 nm and less than or equal to 100 nm.

7. The photovoltaic module according to claim 4, wherein: The refractive index of the first anti-reflection layer is smaller than the refractive index of the second anti-reflection layer.

8. The photovoltaic module according to claim 7, wherein: The refractive index of the first anti-reflection layer is greater than or equal to 1.1 and less than or equal to 1.3; the refractive index of the second anti-reflection layer is greater than or equal to 1.3 and less than or equal to 1.

5.

9. The photovoltaic module according to claim 8, wherein: The refractive index of the first anti-reflection layer is greater than or equal to 1.2 and less than or equal to 1.3; the refractive index of the second anti-reflection layer is greater than or equal to 1.4 and less than or equal to 1.

5.

10. The photovoltaic module according to claim 4, wherein: The porosity of the first anti-reflection layer is greater than the porosity of the second anti-reflection layer.

11. The photovoltaic module according to claim 10, wherein: The porosity of the first anti-reflection layer is greater than or equal to 35% and less than or equal to 60%; the porosity of the second anti-reflection layer is greater than or equal to 10% and less than or equal to 30%.

12. The photovoltaic module according to claim 1, wherein: The light transmittance of the laminate formed by the cover plate and the anti-reflection layer is greater than or equal to 90%.

13. The photovoltaic module according to any one of claims 1 to 12, wherein: The passivation layer includes a first passivation layer and a second passivation layer which are stacked; the first passivation layer is located between the cover plate and the second passivation layer.

14. The photovoltaic module according to claim 13, wherein: One of the first passivation layer and the second passivation layer is an aluminum oxide passivation layer, and the other is a silicon nitride passivation layer; The thickness of the aluminum oxide passivation layer is greater than or equal to 5 nm and less than or equal to 10 nm; the refractive index of the aluminum oxide passivation layer is greater than or equal to 1.5 and less than or equal to 1.8; The thickness of the silicon nitride passivation layer is greater than or equal to 50 nm and less than or equal to 80 nm; the refractive index of the silicon nitride passivation layer is greater than or equal to 1.8 and less than or equal to 2.

2.

15. The photovoltaic module according to claim 13, wherein: The first passivation layer is an aluminum oxide passivation layer, and the second passivation layer is a silicon nitride passivation layer.

16. The photovoltaic module according to claim 1, wherein: The anti-reflection layer includes at least one of a silicon nitride anti-reflection layer, a silicon oxide anti-reflection layer, and a titanium oxide anti-reflection layer.

17. The photovoltaic module according to claim 1, wherein: The battery cell is a back contact battery cell.

18. The photovoltaic module according to claim 1, wherein: The photovoltaic module further comprises: A first adhesive film layer, located between the cover plate and the battery cell; A second adhesive film layer is located between the battery cell and the packaging board; The first adhesive film layer and the second adhesive film layer are used to wrap the battery cell.

19. The photovoltaic module according to claim 1, wherein: The packaging board is a black organic packaging board or a black glaze-plated packaging board; and / or, The photovoltaic module is a fully black photovoltaic module.

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