Solar cell, photovoltaic module and photovoltaic system

Abstract

The invention is applicable to the technical field of solar cells, and provides a solar cell, a photovoltaic module and a photovoltaic system.The solar cell comprises a silicon wafer, the silicon wafer is provided with a front face and a back face which are oppositely arranged, the front face is provided with a first passive film layer, and the back face is provided with a second passive film layer; a first wear-resistant layer is arranged on one side, deviating from the silicon wafer, of the first passivation film layer; and / or, the total thickness of the second passive film layer is 80-160nm, and a second wear-resistant layer is arranged on one side, away from the silicon wafer, of the second passive film layer; the first wear-resistant layer and the second wear-resistant layer are one or two of a silicon dioxide layer and a silicon oxynitride layer, the thickness of the first wear-resistant layer and the second wear-resistant layer is 20-100 nm, and the refractive index of the first wear-resistant layer and the refractive index of the second wear-resistant layer are 1.45-1.65. According to the solar cell, the scratch resistance and the wear resistance of the passivation film layer on the front surface or the back surface can be improved, and the efficiency and the power of the solar cell and the photovoltaic module are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a solar cell, a photovoltaic module and a photovoltaic system. Background Art

[0002] Solar cells are semiconductor devices that can convert solar energy into electrical energy. Under light conditions, photocurrent is generated inside the solar cell, and electrical energy is output through electrodes. In recent years, the production technology of solar cells has been continuously improved, the production cost has been continuously reduced, and the conversion efficiency has been continuously improved. The application of solar cell power generation has become increasingly widespread and has become an important energy source for power supply.

[0003] In the prior art, after the passivation film layer is plated on the front or back of the solar cell, a metallization process and component assembly are required. During these processes, the passivation film layer on the front or back of the cell will come into contact with equipment belts, rollers, process boats / tanks, etc., which can easily cause scratches and wear on the passivation film layer on the front or back of the cell. Wear and scratches are difficult to avoid, which will affect the efficiency and power of the solar cell and the photovoltaic modules composed of the solar cell. Summary of the invention

[0004] The present invention provides a solar cell, aiming to solve the problem that a passivation film layer on the front or back side of the solar cell in the prior art is easily scratched and worn.

[0005] The present invention is implemented by providing a solar cell, comprising:

[0006] The silicon wafer comprises a front side and a back side which are arranged opposite to each other, the front side is provided with a first passivation film layer, and the back side is provided with a second passivation film layer;

[0007] A first wear-resistant layer is disposed on a side of the first passivation film layer away from the silicon wafer, the first wear-resistant layer is a stack of one or both of a silicon dioxide layer and a silicon oxynitride layer, the thickness of the first wear-resistant layer is 20 to 100 nm, and the refractive index of the first wear-resistant layer is 1.45 to 1.65; and / or,

[0008] The total thickness of the second passivation film layer is 80 to 160 nm. A second wear-resistant layer is provided on the side of the second passivation film layer away from the silicon wafer. The second wear-resistant layer is a stack of one or two of a silicon dioxide layer and a silicon oxynitride layer. The thickness of the second wear-resistant layer is 20 to 100 nm, and the refractive index of the second wear-resistant layer is 1.45 to 1.65.

[0009] Preferably, the thickness of the first wear-resistant layer is 30-90 nm, and the refractive index of the first wear-resistant layer is 1.50-1.55.

[0010] Preferably, the thickness of the first wear-resistant layer is 30-50 nm.

[0011] Preferably, the refractive index of the first wear-resistant layer is 1.51-1.54.

[0012] Preferably, the reflectivity of the first wear-resistant layer to sunlight with a wavelength of 250 to 600 nm is 1.2% to 1.57%.

[0013] Preferably, the thickness of the second wear-resistant layer is 40-80 nm, and the refractive index of the second wear-resistant layer is 1.48-1.53.

[0014] Preferably, the thickness of the second wear-resistant layer is 40-60 nm.

[0015] Preferably, the refractive index of the second wear-resistant layer is 1.49-1.52.

[0016] Preferably, the first passivation film layer includes a front passivation layer and an anti-reflection layer stacked in sequence from the front side of the silicon wafer to a direction away from the silicon wafer, and the first wear-resistant layer is located on a side of the anti-reflection layer away from the silicon wafer.

[0017] Preferably, the refractive index of the first wear-resistant layer is smaller than the refractive index of the anti-reflection layer.

[0018] Preferably, the anti-reflection layer includes a first silicon nitride layer and a first silicon oxynitride layer, and the refractive indices of the first silicon nitride layer, the first silicon oxynitride layer, and the first wear-resistant layer decrease in sequence.

[0019] Preferably, the front passivation layer comprises a first silicon oxide layer and a first aluminum oxide layer stacked in sequence from the front side of the silicon wafer toward a direction away from the silicon wafer.

[0020] Preferably, the second passivation film layer includes a tunneling layer, a doping layer, and a back passivation layer stacked in sequence from the back side of the silicon wafer to a direction away from the silicon wafer, and the second wear-resistant layer is located on a side of the back passivation layer away from the silicon wafer.

[0021] Preferably, the back passivation layer includes a second silicon oxide layer, a second aluminum oxide layer, a second silicon nitride layer, and a second silicon oxynitride layer stacked in sequence from the back side of the silicon wafer to the direction away from the silicon wafer, and the second wear-resistant layer is located on the side of the second silicon oxynitride layer away from the silicon wafer, and the refractive indices of the second silicon nitride layer, the second silicon oxynitride layer, and the second wear-resistant layer decrease in sequence.

[0022] Preferably, the first wear-resistant layer has a first thickness in the edge region of the silicon wafer, and has a second thickness in the middle region of the silicon wafer, and the first thickness is greater than the second thickness.

[0023] Preferably, the second wear-resistant layer has a third thickness in the edge region of the silicon wafer, and has a fourth thickness in the middle region of the silicon wafer, and the third thickness is greater than the fourth thickness.

[0024] The present invention also provides a photovoltaic assembly, comprising the above-mentioned solar cell.

[0025] The present invention also provides a photovoltaic system, comprising the photovoltaic assembly mentioned above.

[0026] A solar cell provided by the present invention is provided with a first wear-resistant layer on a side of a first passivation film layer away from a silicon wafer, and / or a second wear-resistant layer on a side of a second passivation film layer away from the silicon wafer; when the first wear-resistant layer is provided on the front side of the silicon wafer, the thickness of the first wear-resistant layer is controlled to be 20-100 nm, and the refractive index of the first wear-resistant layer is 1.45-1.65, and the first wear-resistant layer is used to improve the wear resistance of the front side of the solar cell, and protect the first passivation film layer on the front side of the battery from being easily scratched and worn, which is beneficial to maintaining good battery efficiency and power generation of solar cells and photovoltaic modules; at the same time, the thickness range of the first wear-resistant layer and the refractive index range of the first wear-resistant layer are matched with each other, which can achieve a good anti-reflection effect on the front side of the battery, and reduce the influence of the first wear-resistant layer on the film color of the front side of the battery, which is beneficial to the film color sorting of the solar cell; and the first wear-resistant layer using a silicon dioxide layer or a silicon oxynitride layer has excellent passivation performance, which can improve the passivation performance of the front side of the battery.

[0027] When the second wear-resistant layer is set on the back of the silicon wafer, the thickness of the second wear-resistant layer is controlled to be 20-100nm, and the refractive index of the second wear-resistant layer is 1.45-1.65. The second wear-resistant layer is used to improve the good wear resistance of the back of the solar cell, protect the second passivation film layer on the back of the battery from being easily scratched and worn, and is beneficial to maintaining good battery efficiency and power generation of solar cells and photovoltaic modules; at the same time, the thickness range of the second wear-resistant layer and the refractive index range of the second wear-resistant layer are matched with each other, which is beneficial to the laser opening of the back film layer, and makes the second wear-resistant layer have excellent passivation performance, which can improve the passivation performance of the back of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a solar cell provided by an embodiment of the present invention;

[0029] Figure 2 Another schematic diagram of the structure of a solar cell provided by an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of another structure of a solar cell provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by the terms "upper", "lower", "back", "front", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use scenarios of other materials.

[0035] A solar cell provided by the present invention is provided with a first wear-resistant layer on a side of a first passivation film layer away from a silicon wafer, and / or a second wear-resistant layer on a side of a second passivation film layer away from the silicon wafer; when the first wear-resistant layer is provided on the front side of the silicon wafer, the thickness of the first wear-resistant layer is controlled to be 20-100 nm, and the refractive index of the first wear-resistant layer is 1.45-1.65, and the first wear-resistant layer is used to improve the good wear resistance of the front side of the solar cell, protect the first passivation film layer on the front side of the battery from being scratched and worn, and is conducive to maintaining good battery efficiency and power generation of solar cells and photovoltaic modules; at the same time, the thickness range of the first wear-resistant layer and the refractive index range of the first wear-resistant layer are matched with each other, which can achieve a good anti-reflection effect on the front side of the solar cell, and minimize the influence of the first wear-resistant layer on the front film color, which is conducive to the film color sorting of the solar cell; moreover, the first wear-resistant layer has excellent passivation performance, which can improve the passivation performance of the front side of the battery;

[0036] When the second wear-resistant layer is set on the back of the silicon wafer, the thickness of the second wear-resistant layer is controlled to be 20-100nm, and the refractive index of the second wear-resistant layer is 1.45-1.65. The second wear-resistant layer is used to improve the good wear resistance of the back of the solar cell, protect the second passivation film layer on the back of the battery from being easily scratched and worn, and is beneficial to maintaining good battery efficiency and power generation of solar cells and photovoltaic modules. The second wear-resistant layer within this thickness range and this refractive index range is beneficial to laser opening of the back film layer, and the second wear-resistant layer has excellent passivation performance, which can improve the passivation performance of the back of the battery.

[0037] Please refer to Figure 1-Figure 2 A solar cell provided by the present invention comprises a silicon wafer 1, wherein the silicon wafer 1 has a front side 11 and a back side 12 arranged opposite to each other, the front side 11 is provided with a first passivation film layer 2, and the back side is provided with a second passivation film layer 3;

[0038] A first wear-resistant layer 4 is disposed on the side of the first passivation film layer 2 facing away from the silicon wafer 1. The first wear-resistant layer 4 is a stack of one or both of a silicon dioxide layer and a silicon oxynitride layer. The first wear-resistant layer 4 has a thickness of 20 to 100 nm and a refractive index of 1.45 to 1.65; and / or,

[0039] The total thickness of the second passivation film layer 3 is 80 to 160 nm. A second wear-resistant layer 5 is provided on the side of the second passivation film layer 3 facing away from the silicon wafer 1. The second wear-resistant layer 5 is a stack of one or two of a silicon dioxide layer and a silicon oxynitride layer. The thickness of the second wear-resistant layer 5 is 20 to 100 nm, and the refractive index of the second wear-resistant layer 5 is 1.45 to 1.65.

[0040] In an embodiment of the present invention, the solar cell may be a back-contact solar cell or a double-sided contact solar cell. Specifically, in the case where the solar cell is a back-contact solar cell, the conductive regions of the P and N polarities are alternately arranged on the back of the silicon wafer 1. In the case where the solar cell is a double-sided contact cell, the conductive regions of the P and N polarities are respectively arranged on the front 11 and the back 12 of the silicon wafer 1. For example, the solar cell may be an IBC solar cell, a Topcon solar cell, or a Perc solar cell. Among them, the first wear-resistant layer 4 is applied in different types of batteries in the same anti-wear principle, and all utilize the high hardness and wear resistance of the silicon dioxide layer or the silicon oxynitride layer, and at the same time have good thermal stability and corrosion resistance, and are arranged on the outermost side of the passivation film layer on the front 11 or back 12 of the battery, thereby increasing the scratch resistance and wear resistance of the passivation film layer on the front 11 or back 12 of the battery. Among them, Figure 2 The solar cell shown is a back-contact solar cell.

[0041] In the embodiment of the present invention, the first wear-resistant layer 4 can be set only on the front side 11 of the silicon wafer 1, so as to prevent the first passivation film layer 2 on the front side 11 of the solar cell from being easily worn or scratched; the second wear-resistant layer 5 can also be set only on the back side 12 of the silicon wafer 1, so as to prevent the second passivation film layer 3 on the back side 12 of the solar cell from being easily worn or scratched.

[0042] In an embodiment of the present invention, a first wear-resistant layer 4 is provided on the side of the first passivation film layer 2 facing away from the silicon wafer 1. The first wear-resistant layer 4 is a stack of one or two of a silicon dioxide layer and a silicon oxynitride layer. The thickness of the first wear-resistant layer 4 is controlled to be 20 to 100 nm, and the refractive index of the first wear-resistant layer 4 is 1.45 to 1.6. The thickness range of the first wear-resistant layer 4 and the refractive index range of the first wear-resistant layer 4 cooperate with each other. On the one hand, the first wear-resistant layer 4 within this thickness range and this refractive index range can make the first wear-resistant layer 4 have good wear resistance, protect the first passivation film layer 2 of the battery front 11 from being easily scratched and worn, reduce scratches on the battery front, and help maintain good battery efficiency and power generation of solar cells and photovoltaic modules composed of solar cells; on the other hand, the added first wear-resistant layer 4 can not only achieve a good anti-reflection effect on the front side 11 of the solar cell, which is beneficial to maintaining a good photoelectric conversion efficiency of the battery, but also minimize the influence of the first wear-resistant layer 4 on the film color of the battery front 11, which is beneficial to the film color sorting of the solar cell; in addition, a silicon dioxide layer or a silicon oxynitride layer is used as the first wear-resistant layer 4, so that the first wear-resistant layer 4 also has excellent passivation performance, which can improve the passivation performance of the battery front 11, thereby improving the battery efficiency.

[0043] In the embodiment of the present invention, a second wear-resistant layer 5 is provided on the side of the second passivation film layer 3 away from the silicon wafer 1. The second wear-resistant layer 5 is a stack of one or both of a silicon dioxide layer and a silicon oxynitride layer. The thickness of the second wear-resistant layer 5 is controlled to be 20 to 100 nm, and the refractive index of the second wear-resistant layer 5 is 1.45 to 1.6. The thickness range of the second wear-resistant layer 5 and the refractive index range of the second wear-resistant layer 5 cooperate with each other. On the one hand, the second wear-resistant layer 5 within this thickness range and this refractive index range can make the second wear-resistant layer 5 have good wear resistance, protect the second passivation film layer 3 on the back side 12 of the battery from being easily scratched and worn, reduce scratches on the back side of the battery, and help maintain good battery efficiency and power generation of the solar cell and the photovoltaic module composed of the solar cell. On the other hand, since the added second wear-resistant layer 5 may affect the laser opening of the film layer on the back side 12 of the battery, the second wear-resistant layer 5 with too high a refractive index will absorb more laser light. This results in a large power required for laser film opening, and the refractive index is positively correlated with the density of the film layer. A refractive index that is too low will result in poor density and wear resistance of the second wear-resistant layer 5. Therefore, the thickness range of the second wear-resistant layer 5 and the refractive index range of the second wear-resistant layer 5 are set to the above-mentioned range. The thickness range and the refractive index range of the second wear-resistant layer 5 cooperate with each other, which can not only maintain the good wear resistance of the second wear-resistant layer 5, but also facilitate the laser opening of the back side 12 film layer in the subsequent metallization process, reduce the laser power, thereby reducing costs, and avoid excessive laser power increasing damage to the second passivation film layer 3, thereby ensuring good battery performance.

[0044] As a preferred embodiment of the present invention, a first wear-resistant layer 4 is provided on the front side 11 of the silicon wafer 1, and a second wear-resistant layer 5 is provided on the back side 12 of the silicon wafer 1. The first wear-resistant layer 4 is used to protect the first passivation film layer 2 on the front side 11, so that the first passivation film layer 2 on the front side 11 of the solar cell can be prevented from being easily worn or scratched, and the second passivation film layer 3 on the back side 12 of the solar cell can be prevented from being easily worn or scratched, thereby realizing the protection of the double-sided passivation film layer of the solar cell.

[0045] In the embodiment of the present invention, the thickness and refractive index of the first wear-resistant layer 4 can be flexibly set according to actual conditions. The thickness of the first wear-resistant layer 4 can be any value between 20 and 100 nm; for example, the thickness of the first wear-resistant layer 4 can be any value between 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 42 nm, 45 nm, 50 nm, 51 nm, 52 nm, 53 nm, 55 nm, 58 nm, 60 nm, 62 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 96 nm, and 100 nm.

[0046] The refractive index of the first wear-resistant layer 4 can be any value between 1.45 and 1.60; for example, the refractive index of the first wear-resistant layer 4 can be any value between 1.45, 1.46, 1.47, 1.48, 1.49, 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, and 1.65.

[0047] In an embodiment of the present invention, the thickness of the second wear-resistant layer 5 can be any value between 20 and 100 nm; for example, the thickness of the second wear-resistant layer 5 can be any value between 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 42 nm, 45 nm, 50 nm, 51 nm, 52 nm, 53 nm, 55 nm, 58 nm, 60 nm, 62 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 96 nm, and 100 nm.

[0048] The refractive index of the second wear-resistant layer 5 can be any value between 1.45 and 1.60; for example, the refractive index of the first wear-resistant layer 4 can be any value between 1.45, 1.46, 1.47, 1.48, 1.49, 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, and 1.65.

[0049] In the embodiment of the present invention, the thickness and refractive index of the second wear-resistant layer 5 can be flexibly set according to actual conditions, and the thickness and refractive index of the second wear-resistant layer 5 can be the same as or different from the thickness and refractive index of the first wear-resistant layer 4. For example, the thickness of the second wear-resistant layer 5 is 55 nm, and the refractive index of the second wear-resistant layer 5 is 1.51; the thickness of the first wear-resistant layer 4 is 40 nm, and the refractive index of the first wear-resistant layer 4 is 1.53.

[0050] As an embodiment of the present invention, the thickness of the first wear-resistant layer 4 is 30-90 nm, and the refractive index of the first wear-resistant layer 4 is 1.50-1.55.

[0051] In this embodiment, the thickness of the first wear-resistant layer 4 is preferably 30 to 90 nm, and the refractive index of the first wear-resistant layer 4 is preferably 1.50 to 1.55. The thickness range of the first wear-resistant layer 4 and the refractive index range cooperate with each other, which can further ensure that the first wear-resistant layer 4 has good wear resistance; on the other hand, a good anti-reflection effect on the front side 11 of the solar cell is further achieved, which is beneficial to maintaining a good photoelectric conversion efficiency of the battery, and further reduces the influence of the first wear-resistant layer 4 on the film color of the front side 11 of the battery, which is suitable for the current film color sorting scheme of solar cells and is beneficial to the film color sorting of solar cells; at the same time, the first wear-resistant layer 4 also has a more excellent passivation performance, which can further improve the passivation performance of the first wear-resistant layer 4 on the front side 11 of the battery.

[0052] As an embodiment of the present invention, the thickness of the first wear-resistant layer 4 is 30-50 nm.

[0053] In this embodiment, the thickness of the first wear-resistant layer 4 is preferably 30 to 50 nm. Under the premise of ensuring that the first wear-resistant layer 4 has good wear resistance, a better anti-reflection effect is achieved on the front side 11 of the solar cell, and the influence of the first wear-resistant layer 4 on the film color of the front side 11 of the battery is minimized, which is beneficial to the film color sorting of the solar cell, and the first wear-resistant layer 4 has excellent passivation performance, thereby achieving a balance among the above-mentioned effects.

[0054] As an embodiment of the present invention, the refractive index of the first wear-resistant layer 4 is 1.51-1.54.

[0055] In this embodiment, the refractive index of the first wear-resistant layer 4 is preferably 1.51-1.54, which can further achieve a better anti-reflection effect on the front side 11 of the solar cell.

[0056] As an embodiment of the present invention, the reflectivity of the first wear-resistant layer 4 to sunlight with a wavelength of 250 to 600 nm is 1.2% to 1.57%.

[0057] In this embodiment, the reflectivity of the first wear-resistant layer 4 to sunlight with a wavelength of 250 to 600 nm is controlled to be 1.2% to 1.57%, so that the first wear-resistant layer 4 has an excellent anti-reflection effect on sunlight with a wavelength of 250 to 600 nm, which is beneficial to increase the absorption of solar cells to sunlight with a wavelength of 250 to 600 nm, and is beneficial to improving the conversion efficiency of the battery. For example, the reflectivity of sunlight can be any value among 1.2%, 1.22%, 1.30%, 1.35%, 1.37%, 1.39%, 1.40%, 1.42%, 1.45%, 1.5%, 1.53%, and 1.57%.

[0058] As an embodiment of the present invention, the thickness of the second wear-resistant layer 5 is 40-80 nm, and the refractive index of the second wear-resistant layer 5 is 1.48-1.53.

[0059] In this embodiment, the thickness of the second wear-resistant layer 5 is preferably 40 to 80 nm, and the refractive index of the second wear-resistant layer 5 is preferably 1.48 to 1.53. This thickness range and this refractive index range of the second wear-resistant layer 5 cooperate with each other to ensure that the second wear-resistant layer 5 has good wear resistance, and further facilitates the laser opening of the back side 12 film layer. At the same time, the second wear-resistant layer 5 has excellent passivation performance, maintaining the good passivation performance of the second wear-resistant layer 5 on the back side 12 of the battery.

[0060] As an embodiment of the present invention, the thickness of the second wear-resistant layer 5 is 40-60 nm.

[0061] In this embodiment, the thickness of the second wear-resistant layer 5 is preferably 40 to 60 nm. On the premise of ensuring that the second wear-resistant layer 5 has good wear resistance, it is further beneficial to laser opening of the back surface 12 film layer and to further maintain the good passivation performance of the second wear-resistant layer 5.

[0062] As an embodiment of the present invention, the refractive index of the second wear-resistant layer 5 is 1.49-1.52.

[0063] In this embodiment, the refractive index of the second wear-resistant layer 5 is further preferably 1.49-1.52, which is beneficial to the laser opening of the back surface 12 film layer while ensuring that the second wear-resistant layer 5 has good wear resistance.

[0064] As an embodiment of the present invention, the first passivation film layer 2 includes a front passivation layer and an anti-reflection layer stacked in sequence from the front side 11 of the silicon wafer 1 to the direction away from the silicon wafer 1 , and the first wear-resistant layer 4 is located on the side of the anti-reflection layer away from the silicon wafer 1 .

[0065] In this embodiment, the front passivation layer mainly plays a role in passivating the front side 11 of the silicon wafer 1, and the anti-reflection layer mainly plays a role in anti-reflection of the silicon wafer 1, thereby improving the light utilization rate of the battery front side 11. The first wear-resistant layer 4 is located on the side of the first anti-reflection layer away from the silicon wafer 1, that is, the first wear-resistant layer 4 is located on the outermost side of the battery front side 11, thereby protecting the first passivation film layer 2, reducing the degree of wear or scratches on the first passivation film layer 2, and maintaining the good performance of the first passivation film layer 2.

[0066] As an embodiment of the present invention, the refractive index of the first wear-resistant layer 4 is smaller than the refractive index of the anti-reflection layer.

[0067] In this embodiment, since the first wear-resistant layer 4 is located outside the anti-reflection layer, the refractive index of the first wear-resistant layer 4 is controlled to be smaller than the refractive index of the anti-reflection layer, which is beneficial to the absorption of sunlight by the front side 11 of the battery and to improve the battery conversion efficiency.

[0068] As an embodiment of the present invention, the front passivation layer includes a first silicon oxide layer 21 and a first aluminum oxide layer 22 which are sequentially stacked from the front side 11 of the silicon wafer 1 to a direction away from the silicon wafer 1 .

[0069] In this embodiment, the front passivation layer utilizes a laminated structure composed of a first silicon oxide layer 21 and a first aluminum oxide layer 22 stacked in sequence, which can achieve a good passivation effect on the front side 11 and facilitate the absorption of sunlight by the front side 11 of the battery.

[0070] As an embodiment of the present invention, the anti-reflection layer includes a first silicon nitride layer 23 and a first silicon oxynitride layer 24, and the refractive indexes of the first silicon nitride layer 23, the first silicon oxynitride layer 24, and the first wear-resistant layer 4 decrease in sequence. The first silicon nitride layer 23 may specifically include 1 to 4 layers of silicon nitride film; the first silicon oxynitride layer 24 may specifically include 1 to 4 layers of silicon oxynitride film.

[0071] In this embodiment, the first anti-reflection layer utilizes a stacked structure composed of a first silicon nitride layer 23 and a first silicon oxynitride layer 24, which can achieve a good anti-reflection effect, which is beneficial to the absorption of sunlight by the front side 11 of the battery; moreover, the refractive indices of the first silicon nitride layer 23, the first silicon oxynitride layer 24, and the first wear-resistant layer 4 decrease successively, which is beneficial to further enhance the absorption effect of sunlight by the front side 11 of the battery.

[0072] As an embodiment of the present invention, the second passivation film layer 3 includes a tunneling layer 31, a doping layer 32, and a back passivation layer (unnumbered) stacked in sequence from the back side 12 of the silicon wafer 1 to the direction away from the silicon wafer 1, and the second wear-resistant layer 5 is located on the side of the back passivation layer away from the silicon wafer 1.

[0073] In this embodiment, the solar cell is a back contact solar cell, and the second passivation film layer 3 includes a tunneling layer 31, a doping layer 32, and a back passivation layer in sequence from the back side 12 of the silicon wafer 1 to the direction away from the silicon wafer 1. Among them, the doping layer 32 can be a P-type doping layer or an N-type doping layer. Among them, the doping layer of the P-type doping area of ​​the back side 12 of the silicon wafer 1 is a P-type doping layer, and the doping layer of the N-type doping area of ​​the back side 12 of the silicon wafer 1 is an N-type doping layer. The second wear-resistant layer 5 is located on the side of the back passivation layer away from the silicon wafer 1, and the second wear-resistant layer 5 is used to protect the second passivation film layer 3 composed of the tunneling layer 31, the doping layer 32, and the back passivation layer, to prevent the second passivation film layer 3 from being worn or scratched, and to improve the structural reliability of the second passivation film layer 3. Among them, the back passivation layer can be one or a combination of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, and a silicon oxynitride layer.

[0074] As an embodiment of the present invention, the back passivation layer includes a second silicon oxide layer 33, a second aluminum oxide layer 34, a second silicon nitride layer 35, and a second silicon oxynitride layer 36 which are stacked in sequence from the back side 12 of the silicon wafer 1 to the direction away from the silicon wafer 1, and the second wear-resistant layer 5 is located on the side of the second silicon oxynitride layer 36 away from the silicon wafer 1, and the refractive indices of the second silicon nitride layer 35, the second silicon oxynitride layer 36, and the second wear-resistant layer 5 decrease in sequence.

[0075] In this embodiment, the number of film layers of the second silicon oxide layer 33, the second aluminum oxide layer 34, and the second silicon nitride layer 35 is not limited, and can be a single layer or multiple layers. For example, the second silicon nitride layer 35 includes two layers of silicon nitride films, and the second silicon oxynitride layer 36 includes two layers of silicon oxynitride films.

[0076] In this embodiment, the refractive indices of the second silicon nitride layer 35, the second silicon nitride oxide layer 36, and the second wear-resistant layer 5 decrease successively, which is beneficial to reducing the reflectivity of sunlight irradiated on the back side 12 of the battery, while ensuring the reflection effect of long-wave light transmitted by the front side 11 of the battery, which is beneficial to improving battery efficiency.

[0077] In the embodiment of the present invention, the total thickness of the second passivation film layer 3 is 80-160nm, which can prevent the total thickness of the second passivation film layer 3 from being too large or too small. If the total thickness of the second passivation film layer 3 is greater than 160nm and is matched with the second wear-resistant layer 5, it is not conducive to the laser film opening on the back; and if the total thickness of the second passivation film layer 3 is greater than 80nm and is matched with the second wear-resistant layer 5, it is not conducive to the wear resistance of the back side 12 of the battery. Therefore, under the premise that the total thickness of the second passivation film layer 3 is set to 80-160nm, and the second wear-resistant layer 5 with a thickness of 20-100nm and a refractive index of 1.45-1.65 is matched, a good wear resistance effect of the back side 12 of the battery can be achieved, and it is conducive to the laser film opening of the back side 12 of the battery, avoiding excessive power of the laser film opening.

[0078] Please refer to Figure 3 As an embodiment of the present invention, the first wear-resistant layer 4 located in the edge area of ​​the silicon wafer 1 has a first thickness d1, and the first wear-resistant layer 4 located in the middle area of ​​the silicon wafer 1 has a second thickness d2, and the first thickness d1 is greater than the second thickness d2.

[0079] The first thickness d1 of the first wear-resistant layer 4 at the edge region of the silicon wafer 1 is the average thickness or maximum thickness of the first wear-resistant layer 4 at the edge region of the silicon wafer 1. The second thickness d2 of the first wear-resistant layer 4 at the middle region of the silicon wafer 1 is the average thickness or maximum thickness of the first wear-resistant layer 4 at the middle region of the silicon wafer 1.

[0080] In the present embodiment, since there are many dangling bonds and lattice defects at the edge of the silicon wafer 1 of the solar cell, the passivation effect of the edge area of ​​the silicon wafer 1 is worse than the passivation effect of the middle area of ​​the silicon wafer 1. Therefore, the thickness of the first wear-resistant layer 4 located in the edge area of ​​the silicon wafer 1 is set to be thicker than the thickness of the first wear-resistant layer 4 located in the middle area of ​​the silicon wafer 1, which is beneficial to improving the passivation effect of the edge area of ​​the front side 11 of the silicon wafer 1, balancing the passivation effects of various areas of the front side 11 of the silicon wafer 1, and improving the battery efficiency. At the same time, it can improve the wear resistance of the edge area of ​​the front side 11 of the silicon wafer 1.

[0081] As an embodiment of the present invention, the second wear-resistant layer 5 has a third thickness d3 at the edge area of ​​the silicon wafer 1 , and has a fourth thickness d4 at the middle area of ​​the silicon wafer 1 . The third thickness d3 is greater than the fourth thickness d4.

[0082] The third thickness d3 of the second wear-resistant layer 5 located in the edge area of ​​the silicon wafer 1 is the average thickness or maximum thickness of the second wear-resistant layer 5 located in the edge area of ​​the silicon wafer 1. The third thickness d4 of the second wear-resistant layer 5 located in the middle area of ​​the silicon wafer 1 is the average thickness or maximum thickness of the second wear-resistant layer 5 located in the middle area of ​​the silicon wafer 1.

[0083] In this embodiment, since there are many dangling bonds and lattice defects at the edge of the silicon wafer 1 of the solar cell, the passivation effect of the edge area of ​​the silicon wafer 1 is worse than that of the middle area of ​​the silicon wafer 1. Therefore, the third thickness d3 is set to be greater than the fourth thickness d4, that is, the thickness of the second wear-resistant layer 5 located in the edge area of ​​the silicon wafer 1 is thicker than the thickness of the second wear-resistant layer 5 located in the middle area of ​​the silicon wafer 1, which is beneficial to improving the passivation effect of the edge area of ​​the back side 12 of the silicon wafer 1, balancing the passivation effects of various areas on the back side 12 of the silicon wafer 1, and improving the battery efficiency. At the same time, it can improve the wear resistance of the edge area of ​​the back side 12 of the silicon wafer 1.

[0084] In order to further demonstrate the technical effect achieved by the present invention, the inventors conducted the following experimental comparisons:

[0085] Set up control group 1 and experimental group 1:

[0086] Control group 1: No first wear-resistant layer is provided on the front of each battery cell. The battery cells in control group 1 are numbered A1, A2, ... A10;

[0087] Experimental group 1: The first wear-resistant layer is set on the front of each battery cell. The other structures of the battery cells in the experimental group 1 are exactly the same as those in the control group 1. The battery cells in the experimental group 1 are numbered B1, B2, ... B12 in sequence.

[0088] Under the same test conditions, the percentage of scratch area on the front side of each cell in the control group 1 (the percentage of scratch area on the front side to the front side area of ​​the silicon wafer) is measured as shown in Table 1.

[0089] Table 1

[0090]

[0091] The first wear-resistant layer thickness, the first wear-resistant layer refractive index, the front scratch area ratio (the percentage of the front scratch area to the front area of ​​the silicon wafer), the front reflectivity, and the front film color related data of each battery cell in the experimental group 1 are measured as shown in Table 2.

[0092] Table 2

[0093]

[0094] It can be seen from Table 1 and Table 2 that the first wear-resistant layer is not provided on the front side of each battery cell in the control group 1. Under the same test conditions, the scratch area on the front side of the battery cell in the control group 1 is larger than that of each battery cell in the experimental group 1, that is, the first wear-resistant layer provided on the front side of the battery cell can significantly reduce the scratch area and reduce the occurrence of scratches; at the same time, it can be seen from Table 2 that the thickness of the first wear-resistant layer is set at 20 to 100 nm, and the refractive index of the first wear-resistant layer is set at 1.45 to 1.65, which can make the front side of the battery cell have good scratch and wear resistance, and have a lower front reflectivity, and at the same time, the effect on the film color is relatively small.

[0095] Set up control group 2 and experimental group 2:

[0096] Control group 2: No wear-resistant layer is provided on the back of each battery cell of control group 2, and each battery cell of control group 2 is numbered C1, C2, ..., C10;

[0097] Experimental group 2: A second wear-resistant layer is provided on the back of each battery cell in the experimental group 2, and the other structures of the battery cells are exactly the same as those in the control group 2; the battery cells in the experimental group 2 are numbered D1, D2, ... D13 in sequence;

[0098] 1. The relevant data of each battery cell in the control group 2 are shown in Table 3;

[0099] Table 3

[0100]

[0101] 2. The relevant data of each battery cell in the experimental group 2 are shown in Table 4:

[0102] Table 4

[0103]

[0104] It can be seen from Tables 3 and 4 that, under the same test conditions, the scratch area on the back of the battery cells in the control group 2 is significantly larger than that on the back of each battery cell in the experimental group 2. Setting a second wear-resistant layer on the back of each battery cell in the experimental group 2 can significantly reduce the scratch area and reduce the occurrence of scratches. The back of each battery cell in the experimental group 2 has an obvious wear resistance effect, and scratches are not easy to appear on the back of the battery. At the same time, it can be seen from Table 4 that the thickness of the second wear-resistant layer is set at 20-100nm, and the refractive index of the second wear-resistant layer is set at 1.45-1.65, which can make the back of the battery cell have good scratch and wear resistance, and keep the back laser film opening power low, which is conducive to back laser film opening.

[0105] Design experimental group three, experimental group four, experimental group five:

[0106] Experimental group three: The back of the battery in experimental group three is provided with a second wear-resistant layer, and the thickness of the second wear-resistant layer is 50nm; the battery cells in experimental group three are numbered E1, E2, ... E5, and the total thickness of the second passivation film layer corresponding to each battery cell is 50nm, 55nm, 60nm, 70nm, 80nm;

[0107] The relevant data of each battery cell in the experimental group 3 are shown in Table 5:

[0108] Table 5

[0109] Cell number E1 E2 E3 E4 E5 Ratio of scratch area on the back 0.11％ 0.10％ 0.12％ 0.11％ 0.11％ Laser film opening power (W) 1.0 1.11 1.2 1.3 1.4

[0110] Experimental group 4: The back of the battery in experimental group 4 is provided with a second wear-resistant layer, and the thickness of the second wear-resistant layer is 50nm; the battery cells in experimental group 4 are numbered F1, F2...F5 in sequence; and the total thickness of the second passivation film layer corresponding to each battery cell is 85nm, 100nm, 120nm, 140nm, and 160nm;

[0111] The relevant data of each battery cell in the experimental group 4 are measured as shown in Table 6:

[0112] Table 6

[0113] F1 F2 F3 F4 F5 Ratio of scratch area on the back 0.09％ 0.08％ 0..07％ 0.06％ 0.05％ Laser film opening power (W) 1.5 1.6 1.77 1.8 1.9

[0114] Experimental Group 5: The back of the battery in Experimental Group 5 is provided with a second wear-resistant layer, and the thickness of the second wear-resistant layer is 50nm; the battery cells in Experimental Group 5 are numbered G1, G2, ... G5 in sequence; and the total thickness of the second passivation film layer corresponding to each battery cell is 165nm, 180nm, 200nm, 220nm, 240nm; the relevant data of each battery cell in Experimental Group 4 are measured as shown in Table 7 below:

[0115] Table 7

[0116] G1 G2 G3 G4 G5 Ratio of scratch area on the back 0.05％ 0.05％ 0.04％ 0.04％ 0.04％ Laser film opening power (W) 2.0 2.1 2.2 2.3 2.4

[0117] It can be seen from Tables 5 to 7 that the total thickness of the second passivation film layer on the back of the battery is controlled in the range of 80 to 160 nm. At the same time, it is matched with a second wear-resistant layer, which can not only make the back of the battery more resistant to wear, but also make the back laser opening power lower, which is conducive to the back laser opening.

[0118] The embodiment of the present invention further provides a photovoltaic module, which includes the solar cell of the above embodiment. It should be noted that the photovoltaic module has the same or similar beneficial effects as the above solar cell, and the relevant parts between the two can be referenced to each other. In order to avoid repetition, they will not be described here.

[0119] In this embodiment, multiple solar cells in the photovoltaic module can be connected in series in sequence to form a battery string, thereby realizing the series bus output of the current. For example, the series connection of the battery cells can be realized by setting welding strips (bus bars, interconnection bars), conductive backplanes, etc.

[0120] It is understandable that in such an embodiment, the photovoltaic module may also include a metal frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the solar cell and the photovoltaic glass, adjacent cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0121] Photovoltaic glass can cover the adhesive film on the front of the solar cell. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the solar cell without affecting the efficiency of the solar cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the solar cell together. The presence of the adhesive film can seal and insulate the solar cell and make it waterproof and moisture-proof.

[0122] The backplane can be attached to the adhesive film on the back of the solar cell. The backplane can protect and support the solar cell and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to the specific situation and is not limited here. The whole composed of the backplane, solar cell, adhesive film and photovoltaic glass can be set on a metal frame. The metal frame serves as the main external support structure of the entire solar photovoltaic module and can stably support and install the solar photovoltaic module. For example, the solar photovoltaic module can be installed at the required location through the metal frame.

[0123] The embodiment of the present invention further provides a photovoltaic system, which includes the photovoltaic assembly of the above embodiment. It should be noted that the photovoltaic system has the same or similar beneficial effects as the above solar cell, and the relevant parts between the two can be referenced to each other. In order to avoid repetition, they will not be described here.

[0124] In this embodiment, the photovoltaic system can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple solar photovoltaic components. For example, multiple solar photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0125] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0126] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solar cell, characterized in that: The silicon wafer comprises a front side and a back side which are arranged opposite to each other, the front side is provided with a first passivation film layer, and the back side is provided with a second passivation film layer; A first wear-resistant layer is disposed on a side of the first passivation film layer away from the silicon wafer, the first wear-resistant layer is a stack of one or both of a silicon dioxide layer and a silicon oxynitride layer, the thickness of the first wear-resistant layer is 20 to 100 nm, and the refractive index of the first wear-resistant layer is 1.45 to 1.65; and / or, The total thickness of the second passivation film layer is 80 to 160 nm. A second wear-resistant layer is provided on the side of the second passivation film layer away from the silicon wafer. The second wear-resistant layer is a stack of one or two of a silicon dioxide layer and a silicon oxynitride layer. The thickness of the second wear-resistant layer is 20 to 100 nm, and the refractive index of the second wear-resistant layer is 1.45 to 1.

65.

2. The solar cell according to claim 1, characterized in that: The thickness of the first wear-resistant layer is 30-90 nm, and the refractive index of the first wear-resistant layer is 1.50-1.

55.

3. The solar cell according to claim 1, characterized in that The thickness of the first wear-resistant layer is 30-50 nm.

4. The solar cell according to claim 1, characterized in that The refractive index of the first wear-resistant layer is 1.51-1.

54.

5. The solar cell according to claim 1, characterized in that: The reflectivity of the first wear-resistant layer to sunlight with a wavelength of 250 to 600 nm is 1.2% to 1.57%.

6. The solar cell according to claim 1, characterized in that The thickness of the second wear-resistant layer is 40-80 nm, and the refractive index of the second wear-resistant layer is 1.48-1.

53.

7. The solar cell according to claim 1, characterized in that The second wear-resistant layer has a thickness of 40 to 60 nm.

8. The solar cell according to claim 1, characterized in that The refractive index of the second wear-resistant layer is 1.49-1.

52.

9. The solar cell according to claim 1, characterized in that: The first passivation film layer includes a front passivation layer and an anti-reflection layer stacked in sequence from the front side of the silicon wafer to the direction away from the silicon wafer, and the first wear-resistant layer is located on a side of the anti-reflection layer away from the silicon wafer.

10. The solar cell according to claim 9, characterized in that: The refractive index of the first wear-resistant layer is smaller than the refractive index of the anti-reflection layer.

11. The solar cell according to claim 9, characterized in that: The anti-reflection layer includes a first silicon nitride layer and a first silicon oxynitride layer, and the refractive indices of the first silicon nitride layer, the first silicon oxynitride layer, and the first wear-resistant layer decrease in sequence.

12. The solar cell according to claim 1, characterized in that The front passivation layer includes a first silicon oxide layer and a first aluminum oxide layer stacked in sequence from the front side of the silicon wafer to a direction away from the silicon wafer.

13. The solar cell according to claim 1, characterized in that The second passivation film layer includes a tunneling layer, a doping layer, and a back passivation layer stacked in sequence from the back side of the silicon wafer to a direction away from the silicon wafer, and the second wear-resistant layer is located on a side of the back passivation layer away from the silicon wafer.

14. The solar cell according to claim 13, characterized in that: The back passivation layer includes a second silicon oxide layer, a second aluminum oxide layer, a second silicon nitride layer, and a second silicon oxynitride layer stacked in sequence from the back side of the silicon wafer to the direction away from the silicon wafer. The second wear-resistant layer is located on the side of the second silicon oxynitride layer away from the silicon wafer, and the refractive indices of the second silicon nitride layer, the second silicon oxynitride layer, and the second wear-resistant layer decrease in sequence.

15. The solar cell according to claim 1, characterized in that The first wear-resistant layer is located in the edge area of ​​the silicon wafer and has a first thickness. The first wear-resistant layer is located in the middle area of ​​the silicon wafer and has a second thickness. The first thickness is greater than the second thickness.

16. The solar cell according to claim 1, characterized in that The second wear-resistant layer is located in the edge area of ​​the silicon wafer and has a third thickness. The second wear-resistant layer is located in the middle area of ​​the silicon wafer and has a fourth thickness. The third thickness is greater than the fourth thickness.

17. A photovoltaic module, characterized in that: Comprising the solar cell according to any one of claims 1 to 16.

18. A photovoltaic system, characterized in that: Comprising the photovoltaic module as claimed in claim 17.

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