Back contact solar cell and photovoltaic module
Patent Information
- Application Number
- CN202511436563.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-09
- Publication Date
- 2026-05-22
AI Technical Summary
In back-contact solar cells, leakage can easily occur between different types of conductive semiconductor layers, affecting photoelectric conversion efficiency and reliability.
In a back-contact solar cell, a first dielectric layer and a first conductive semiconductor layer are stacked sequentially in a first region, and a second dielectric layer and a second conductive semiconductor layer are stacked sequentially in a second region. The second conductive semiconductor layer extends to the side of the first conductive semiconductor layer away from the substrate. The conductive portions of the conductive layers are spaced apart to avoid overlapping, ensuring that there is no contact between the conductive layers.
This significantly reduces the risk of leakage between conductive semiconductor layers, improves carrier collection efficiency and photoelectric conversion efficiency, and enhances reliability.
Smart Images
Figure CN122073893A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic cell technology, and in particular to back-contact solar cells and photovoltaic modules. Background Technology
[0002] Solar cells, also known as photovoltaic cells, are semiconductor devices that directly convert sunlight into electrical energy. Because they are green and environmentally friendly products that do not cause pollution, and because solar energy is a renewable resource, solar cells are a new type of battery with broad development prospects.
[0003] Currently, mainstream solar cells include tunnel oxide passivated contact (TOPCon), interdigitated back contact (IBC), and heterojunction (HJT) cells. The most significant feature of back contact (BC) cells is that the metal electrode is located on the back surface of the cell, and there is no metal electrode blocking the front surface, which improves the light utilization rate and thus has higher short-circuit current and conversion efficiency.
[0004] In related technologies, leakage current is prone to occur between different types of conductive semiconductor layers in back-contact solar cells, which affects the improvement of photoelectric conversion efficiency and reliability of back-contact solar cells. Summary of the Invention
[0005] Based on this, this application provides a back-contact solar cell and photovoltaic module, which can reduce the risk of leakage current, improve photoelectric conversion efficiency and reliability.
[0006] An embodiment of the first aspect of this application provides a back-contact solar cell, comprising:
[0007] A semiconductor substrate having a first surface and a second surface opposite to each other, the first surface including a first region and a second region disposed adjacent to each other;
[0008] A first dielectric layer and a first conductive semiconductor layer are sequentially stacked in the first region along a direction away from the semiconductor substrate;
[0009] A second dielectric layer and a second conductive semiconductor layer are sequentially stacked in the second region along a direction away from the semiconductor substrate; the second dielectric layer and the second conductive semiconductor layer further extend to the side of the first conductive semiconductor layer away from the semiconductor substrate; the second conductive semiconductor layer includes a first surface away from the first conductive semiconductor layer along a first direction and a first side surface away from the first dielectric layer and the first conductive semiconductor layer along a second direction; the first surface is connected to the first side surface; the first direction is the thickness direction of the semiconductor substrate; the second direction is the direction from the first region to the second region;
[0010] A conductive layer includes a first conductive portion and a second conductive portion disposed at intervals, wherein the first conductive portion is disposed on the side of the first conductive semiconductor layer away from the semiconductor substrate; and the second conductive portion is disposed on the side of the second conductive semiconductor layer away from the semiconductor substrate.
[0011] In the second direction, the side of the second conductive semiconductor layer near the first conductive portion has a first distance D1 between it and the side of the first conductive portion near the second conductive semiconductor layer, where D1 > 0.
[0012] In the second direction, the first side and the side of the second conductive portion closest to the first side have a second distance D2, where D2 > 0.
[0013] In one embodiment, the first distance and the second distance satisfy the following relationship: D1≥D2.
[0014] In one embodiment, the first distance D1 is between 0.005µm and 100µm.
[0015] In one embodiment, the second distance D2 is between 0.001µm and 100µm.
[0016] In one embodiment, the second dielectric layer includes a first sub-part, a second sub-part, and a third sub-part; the first sub-part is disposed on a surface of the first conductive semiconductor layer away from the semiconductor substrate; the second sub-part is disposed on a first surface located in the second region; the third sub-part connects the first sub-part and the second sub-part; and the third sub-part covers the side surface of the dielectric layer and the side surface of the first conductive semiconductor layer.
[0017] The second conductive semiconductor layer includes a fourth sub-part, a fifth sub-part, and a sixth sub-part; the fourth sub-part is disposed on the side of the first sub-part away from the semiconductor substrate; the fifth sub-part is disposed on the side of the second sub-part away from the semiconductor substrate; the sixth sub-part is disposed on the side of the third sub-part along the second direction, and the sixth sub-part connects the fourth sub-part and the fifth sub-part.
[0018] Wherein, the surface of the fourth sub-part away from the first conductive semiconductor layer along the first direction is the first surface; the surface of the sixth sub-part away from the third sub-part along the second direction is the first side surface;
[0019] In the second direction, there is a first distance D1 between the side of the fourth sub-part near the first conductive part and the side of the first conductive part near the fourth sub-part;
[0020] In the second direction, there is a second distance D2 between the side of the sixth sub-part away from the third sub-part and the side of the second conductive part close to the sixth sub-part.
[0021] In one embodiment, the orthogonal projection of the first conductive semiconductor layer onto the semiconductor substrate has a first length L1 in the second direction;
[0022] The orthographic projection of the fourth sub-part onto the semiconductor substrate has a second length L2 in the second direction; the ratio of the second length L2 to the first length L1 is between (0.01 to 0.3):1.
[0023] In one embodiment, the first conductive portion is disposed on the surface of the first conductive semiconductor layer away from the semiconductor substrate; the orthographic projection of the first conductive portion on the semiconductor substrate is within the orthographic projection range of the first conductive semiconductor layer on the semiconductor substrate; and the orthographic projection of the first conductive portion on the semiconductor substrate is spaced apart from the orthographic projection of the fourth sub-part on the semiconductor substrate; the second conductive portion is disposed on the surface of the fifth sub-part away from the semiconductor substrate, the orthographic projection of the second conductive portion on the semiconductor substrate is within the orthographic projection range of the fifth sub-part on the semiconductor substrate; and the orthographic projection of the second conductive portion on the semiconductor substrate is spaced apart from the orthographic projection of the sixth sub-part on the semiconductor substrate; and / or...
[0024] The back-contact solar cell further includes a first electrode and a second electrode, wherein the first electrode is disposed on the side of the first conductive portion away from the semiconductor substrate; the second electrode is disposed on the side of the second conductive portion away from the semiconductor substrate; and / or,
[0025] The conductive layer includes a transparent conductive layer.
[0026] In one embodiment, the first dielectric layer includes a tunneling oxide layer; and / or,
[0027] The first conductive semiconductor layer includes a doped polysilicon layer; and / or,
[0028] The second dielectric layer includes an intrinsic amorphous silicon layer; and / or,
[0029] The second conductive semiconductor layer includes one of a doped amorphous silicon layer, a doped microcrystalline silicon layer, and a doped nanocrystalline silicon layer.
[0030] In one embodiment, the back-contact solar cell further includes a passivation layer and an antireflection layer, the passivation layer being disposed on the second surface; the antireflection layer being disposed on the side of the passivation layer away from the semiconductor substrate.
[0031] An embodiment of the second aspect of this application provides a photovoltaic module including the back-contact solar cell described in any of the above embodiments.
[0032] The aforementioned back-contact solar cell and photovoltaic module, by sequentially stacking a first dielectric layer and a first conductive semiconductor layer in a first region along a direction away from the semiconductor substrate; and sequentially stacking a second dielectric layer and a second conductive semiconductor layer in a second region along a direction away from the second semiconductor substrate; the second dielectric layer and the second conductive semiconductor layer further extend to the side of the first conductive semiconductor layer away from the semiconductor substrate, thereby increasing the projected area of the first and second conductive semiconductor layers on the first surface of the semiconductor substrate, which is beneficial to improving carrier collection efficiency and photoelectric conversion efficiency; the second conductive semiconductor layer includes a first surface away from the first conductive semiconductor layer along a first direction and a first side surface away from the first dielectric layer and the first conductive semiconductor layer along a second direction; the first surface and the first side surface are connected. By placing the first conductive portion on the side of the first conductive semiconductor layer away from the semiconductor substrate, and the second conductive portion on the side of the second conductive semiconductor layer away from the semiconductor substrate, in a second direction (i.e., the direction from the first region to the second region), the side of the second conductive semiconductor layer near the first conductive portion has a first distance D1 (D1 > 0) with the side of the first conductive portion near the second conductive semiconductor layer; in the second direction, the first side surface has a second distance D2 with the side of the second conductive portion near the first side surface. In other words, the side of the second conductive semiconductor layer near the first conductive portion is separated from the first conductive portion, and the first side surface is separated from the side of the second conductive portion near the first side surface. This ensures that the conductive layer completely avoids all overlapping and contact areas between the first and second conductive semiconductor layers, thereby significantly reducing the leakage risk between the first and second conductive semiconductor layers and improving reliability. Furthermore, the good conductivity of the first and second conductive portions helps improve carrier collection efficiency and photoelectric conversion efficiency. In summary, this application can significantly reduce the leakage risk between the first and second conductive semiconductor layers, improve photoelectric conversion efficiency, and enhance reliability. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the structure of a back-contact solar cell in some embodiments of this application.
[0034] Explanation of reference numerals in the attached figures:
[0035] 11. Semiconductor substrate; 111. First surface; 112. Second surface; 11a. First region; 11b. Second region; 121. First dielectric layer; 122. First conductive semiconductor layer; 131. Second dielectric layer; 1311. First sub-section; 1312. Second sub-section; 1313. Third sub-section; 132. Second conductive semiconductor layer; 1321. Fourth sub-section; 1322. Fifth sub-section; 1323. Sixth sub-section; 132a. First surface; 132b. First side surface; 14. Conductive layer; 141. First conductive portion; 142. Second conductive portion; 151. First electrode; 152. Second electrode; 16. Passivation layer; 17. Anti-reflection layer; X. First direction; Y. Second direction. Detailed Implementation
[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0037] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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 orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0038] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0040] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0041] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.
[0042] Firstly, see Figure 1This application provides a back-contact solar cell, including a semiconductor substrate 11, a first dielectric layer 121, a first conductive semiconductor layer 122, a second dielectric layer 131, a second conductive semiconductor layer 132, and a conductive layer 14. The semiconductor substrate 11 has opposing first surfaces 111 and second surfaces 112. The first surface 111 includes adjacent first regions 11a and second regions 11b. The first dielectric layer 121 and the first conductive semiconductor layer 122 are sequentially stacked in the first region 11a along a direction away from the semiconductor substrate 11. The second dielectric layer 131 and the second conductive semiconductor layer 132 are sequentially stacked in the second region 11b along a direction away from the semiconductor substrate 11. The second dielectric layer 131 and the second conductive semiconductor layer 132 also extend to the side of the first conductive semiconductor layer 122 away from the semiconductor substrate 11. The second conductive semiconductor layer 132 includes a first surface 132a along a first direction X away from the first conductive semiconductor layer 122 and a second surface 132a along a second direction Y away from the first conductive semiconductor layer 122. The first dielectric layer 121 and the first conductive semiconductor layer 122 have a first side surface 132b; the first surface 132a is connected to the first side surface 132b; the first direction X is the thickness direction of the semiconductor substrate 11; the second direction Y is the direction from the first region 11a to the second region 11b; the conductive layer 14 includes a first conductive portion 141 and a second conductive portion 142 disposed at intervals, the first conductive portion 141 is disposed on the side of the first conductive semiconductor layer 122 away from the semiconductor substrate 11; the second conductive portion 142 is disposed on the side of the second conductive semiconductor layer 132 away from the semiconductor substrate 11; wherein, in the second direction Y, the side of the second conductive semiconductor layer 132 near the first conductive layer 14 and the side of the first conductive portion 141 near the second conductive semiconductor layer 132 have a first distance D1, D1 > 0; in the second direction Y, the first side surface 132b and the side of the second conductive portion 142 near the first side surface 132b have a second distance D2, D2 > 0.
[0043] The back-contact solar cell provided in this application embodiment has a first dielectric layer 121 and a first conductive semiconductor layer 122 sequentially stacked in a first region 11a along a direction away from the semiconductor substrate 11; a second dielectric layer 131 and a second conductive semiconductor layer 132 sequentially stacked in a second region 11b along a direction away from the second semiconductor substrate 11; the second dielectric layer 131 and the second conductive semiconductor layer 132 also extend to the side of the first conductive semiconductor layer 122 away from the semiconductor substrate 11, thereby increasing the projected area of the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132 on the first surface 111 of the semiconductor substrate 11, which is beneficial to improving the carrier collection efficiency and the photoelectric conversion efficiency; the second conductive semiconductor layer 132 includes a first surface 132a away from the first conductive semiconductor layer 122 along a first direction X and a first side surface 132b away from the first dielectric layer 121 and the first conductive semiconductor layer 122 along a second direction Y; the first surface 132a and the first side surface 132b are connected. By disposing the first conductive portion 141 on the side of the first conductive semiconductor layer 122 away from the semiconductor substrate 11, and the second conductive portion 142 on the side of the second conductive semiconductor layer 132 away from the semiconductor substrate 11, in the second direction Y, i.e., in the direction from the first region 11a to the second region 11b, the side of the second conductive semiconductor layer 132 near the first conductive portion 141 and the side of the first conductive portion 141 near the second conductive semiconductor layer 132 have a first distance D1, where D1 > 0; in the second direction Y, the first side surface 132b and the second conductive portion 142... The side closest to the first side 132b has a second distance D2, where D2 > 0. This means that the side of the second conductive semiconductor layer 132 closest to the first conductive portion 141 is separated from the first conductive portion 141, and the first side 132b is separated from the side of the second conductive portion closest to the first side 132b. This ensures that the conductive layer 14 completely avoids all overlapping and contact areas between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132, thereby significantly reducing the leakage risk between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132 and improving reliability. Furthermore, the excellent conductivity of the first conductive portion 141 and the second conductive portion 142 helps improve carrier collection efficiency and photoelectric conversion efficiency. In summary, this application can significantly reduce the leakage risk between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132, and improve the photoelectric conversion efficiency and reliability of the back-contact solar cell.
[0044] Understandably, the first surface 111 can be a backlight surface, and the second surface 112 can be a light-receiving surface, with a textured surface structure provided on the second surface 112. A textured surface structure is provided on the first surface 111 located in the second region 11b. The first region 11a and the second region 11b can be arranged in alternating stripe patterns or in an interdigitated pattern. One of the first region 11a and the second region 11b corresponds to a P-region, and the other corresponds to an N-region; one of the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132 can be a P-type conductive semiconductor layer, and the other can be an N-type conductive semiconductor layer.
[0045] In one embodiment, the first region 11a is an N-region, the second region 11b is a P-region, the first conductive semiconductor layer 122 is an N-type conductive semiconductor layer, and the second conductive semiconductor layer 132 is a P-type conductive semiconductor layer.
[0046] In one embodiment, the first distance and the second distance satisfy the following relationship: D1≥D2.
[0047] In this way, while ensuring that the side of the second conductive semiconductor layer 132 closest to the first conductive portion 141 is separated from the first conductive portion 141, and the first side surface 132b is separated from the side of the second conductive portion 142 closest to the first side surface 132b, the projected area of the first conductive portion 141 in the first region 11a is larger, and the projected area of the second conductive portion 142 in the second region 11b is larger. This can greatly reduce the risk of leakage between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132, which is beneficial to the collection of charge carriers in the first region 11a and the second region 11b, thereby improving the photoelectric conversion efficiency and reliability of the back contact solar cell.
[0048] In one embodiment, the first distance D1 is between 0.005µm and 100µm. Specifically, the first distance D1 can be any value among 0.005µm to 10µm, 10µm to 20µm, 20µm to 30µm, 30µm to 40µm, 40µm to 50µm, 50µm to 60µm, 60µm to 70µm, 70µm to 80µm, 80µm to 90µm, 90µm to 100µm, or 0.005µm to 100µm.
[0049] Thus, by limiting the first distance D1 to the above-mentioned numerical range, it can be ensured that the first conductive part 141 and the side of the second conductive semiconductor layer 132 close to the first conductive part 141 are separated, reducing the risk of leakage of the back contact solar cell; in addition, it can ensure the positive projection area of the first conductive part 141 in the first region 11a, improve the carrier collection efficiency of the first region 11a, thereby improving the photoelectric conversion efficiency of the back contact solar cell.
[0050] In one embodiment, the second distance D2 is between 0.001µm and 100µm. Specifically, the second distance D2 can be any value among 0.001µm to 5µm, 5µm to 15µm, 15µm to 25µm, 25µm to 35µm, 35µm to 45µm, 45µm to 55µm, 55µm to 65µm, 65µm to 75µm, 75µm to 85µm, 85µm to 100µm, or 0.001µm to 100µm.
[0051] Thus, by limiting the second distance D2 within the aforementioned numerical range, the second conductive portion 142 can be separated from the first side surface 132b of the second conductive semiconductor layer 132, reducing the risk of leakage in the back-contact solar cell. In addition, the projected area of the second conductive portion 142 in the second region 11b can be guaranteed, improving the carrier collection efficiency of the second region 11b, thereby improving the photoelectric conversion efficiency of the back-contact solar cell.
[0052] In one embodiment, see [reference] Figure 1 The second dielectric layer 131 includes a first sub-part 1311, a second sub-part 1312, and a third sub-part 1313; the first sub-part 1311 is disposed on the surface of the first conductive semiconductor layer 122 away from the semiconductor substrate 11; the second sub-part 1312 is disposed on the first surface 132a located in the second region 11b; the third sub-part 1313 connects the first sub-part 1311 and the second sub-part 1312; and the third sub-part 1313 covers the side surface of the dielectric layer and the side surface of the first conductive semiconductor layer 122; the second conductive semiconductor layer 132 includes a fourth sub-part 1321, a fifth sub-part 1322, and a sixth sub-part 1323; the fourth sub-part 1321 is disposed on the side of the first sub-part 1311 away from the semiconductor substrate 11; the fifth sub-part 1322 is disposed on the side of the second sub-part 1312 away from the semiconductor substrate 11. The sixth sub-part 1323 is disposed on one side of the third sub-part 1313 along the second direction Y, and the sixth sub-part 1323 connects the fourth sub-part 1321 and the fifth sub-part 1322; wherein, the surface of the fourth sub-part 1321 away from the first conductive semiconductor layer 122 along the first direction X is the first surface 132a; the surface of the sixth sub-part 1323 away from the third sub-part 1313 along the second direction Y is the first side surface 132b; in the second direction Y, there is a first distance D1 between the side of the fourth sub-part 1321 near the first conductive part 141 and the side of the first conductive part 141 near the fourth sub-part 1321; in the second direction Y, there is a second distance D2 between the side of the sixth sub-part 1323 away from the third sub-part 1313 and the side of the second conductive part 142 near the sixth sub-part 1323.
[0053] In this way, the first conductive portion 141 can be separated from the fourth sub-portion 1321 of the second conductive semiconductor layer 132, and the sixth sub-portion 1323 of the second conductive semiconductor layer 132 can be separated from the second conductive portion 142, which greatly reduces the risk of leakage between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132 and improves the reliability of the back contact solar cell.
[0054] It should be noted that, for reference Figure 1 In the second direction Y, there is also a first distance D1 between the side of the first sub-part 1311 near the first conductive part 141 and the end of the first conductive part 141 near the first sub-part 1311. That is, the orthographic projection of the side of the first sub-part 1311 near the first conductive part 141 on the semiconductor substrate 11 coincides with the orthographic projection of the side of the fourth sub-part 1321 near the first conductive part 141 on the semiconductor substrate 11. In this way, the first conductive part 141 is separated from the first sub-part 1311 of the second dielectric layer 131, reducing the risk of leakage and improving the reliability of the back contact solar cell.
[0055] In one embodiment, see [reference] Figure 1 The first conductive semiconductor layer 122 has a first length L1 in the second direction Y when projected onto the semiconductor substrate 11; the fourth sub-part 1321 has a second length L2 in the second direction Y when projected onto the semiconductor substrate 11; the ratio of the second length L2 to the first length L1 is between (0.01 to 0.3):1.
[0056] In other words, the second length L2 of the orthographic projection of the fourth sub-part 1321 on the semiconductor substrate 11 in the second direction Y is much smaller than the first length L1 of the orthographic projection of the first conductive semiconductor layer 122 on the semiconductor substrate 11 in the second direction Y. This effectively reduces the overlap area between the orthographic projections of the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132 on the semiconductor substrate 11, thereby greatly reducing the leakage area and lowering the risk of leakage.
[0057] It should be noted that, for reference Figure 1 The first sub-part 1311 has a third length L3 in the second direction Y when projected onto the semiconductor substrate 11. The ratio of the third length L3 to the first length L1 is between (0.01 and 0.3):1.
[0058] In one embodiment, see [reference] Figure 1The first conductive portion 141 is disposed on the surface of the first conductive semiconductor layer 122 away from the semiconductor substrate 11; the orthographic projection of the first conductive portion 141 on the semiconductor substrate 11 is within the orthographic projection range of the first conductive semiconductor layer 122 on the semiconductor substrate 11; and the orthographic projection of the first conductive portion 141 on the semiconductor substrate 11 is spaced apart from the orthographic projection of the fourth sub-portion 1321 on the semiconductor substrate 11; the second conductive portion 142 is disposed on the surface of the fifth sub-portion 1322 away from the semiconductor substrate 11; the orthographic projection of the second conductive portion 142 on the semiconductor substrate 11 is within the orthographic projection range of the fifth sub-portion 1322 on the semiconductor substrate 11; and the orthographic projection of the second conductive portion 142 on the semiconductor substrate 11 is spaced apart from the orthographic projection of the sixth sub-portion 1323 on the semiconductor substrate 11.
[0059] In this way, the first conductive portion 141 can be separated from the fourth sub-portion 1321 of the second conductive semiconductor layer 132, and the sixth sub-portion 1323 of the second conductive semiconductor layer 132 can be separated from the second conductive portion 142, which greatly reduces the risk of leakage between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 132 and improves the reliability of the back contact solar cell.
[0060] In one embodiment, see [reference] Figure 1 The back-contact solar cell also includes a first electrode 151 and a second electrode 152. The first electrode 151 is disposed on the side of the first conductive portion 141 away from the semiconductor substrate 11; the second electrode 152 is disposed on the side of the second conductive portion 142 away from the semiconductor substrate 11.
[0061] In one embodiment, the conductive layer 14 includes a transparent conductive layer.
[0062] In one embodiment, the first dielectric layer 121 includes a tunneling oxide layer, specifically, the tunneling oxide layer may be any material with a tunneling effect such as silicon oxide, aluminum oxide, titanium oxide and zinc oxide; and / or, the first conductive semiconductor layer 122 includes a doped polycrystalline silicon layer.
[0063] In one embodiment, the second dielectric layer 131 includes an intrinsic amorphous silicon layer; and / or, the second conductive semiconductor layer 132 includes one of a doped amorphous silicon layer, a doped microcrystalline silicon layer, and a doped nanocrystalline silicon layer.
[0064] In one embodiment, see [reference] Figure 1 The back-contact solar cell also includes a passivation layer 16 and an anti-reflection layer 17. The passivation layer 16 is disposed on the second surface 112; the anti-reflection layer 17 is disposed on the side of the passivation layer 16 away from the semiconductor substrate 11.
[0065] This improves the passivation effect of the second surface 112, reduces recombination, decreases light reflection, and increases light utilization, thereby improving the photoelectric conversion efficiency of the back-contact solar cell.
[0066] Secondly, embodiments of this application provide a photovoltaic module, including the back-contact solar cell in any of the above embodiments. This significantly reduces the leakage risk of the photovoltaic module and improves its photoelectric conversion efficiency and reliability.
[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0068] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A back-contact solar cell, characterized in that, include: A semiconductor substrate having a first surface and a second surface opposite to each other, the first surface including a first region and a second region disposed adjacent to each other; A first dielectric layer and a first conductive semiconductor layer are sequentially stacked in the first region along a direction away from the semiconductor substrate; A second dielectric layer and a second conductive semiconductor layer are sequentially stacked in the second region along a direction away from the semiconductor substrate; the second dielectric layer and the second conductive semiconductor layer further extend to the side of the first conductive semiconductor layer away from the semiconductor substrate; the second conductive semiconductor layer includes a first surface away from the first conductive semiconductor layer along a first direction and a first side surface away from the first dielectric layer and the first conductive semiconductor layer along a second direction; the first surface is connected to the first side surface; the first direction is the thickness direction of the semiconductor substrate; the second direction is the direction from the first region to the second region; A conductive layer includes a first conductive portion and a second conductive portion disposed at intervals, wherein the first conductive portion is disposed on the side of the first conductive semiconductor layer away from the semiconductor substrate; and the second conductive portion is disposed on the side of the second conductive semiconductor layer away from the semiconductor substrate. In the second direction, the side of the second conductive semiconductor layer near the first conductive portion has a first distance D1 between it and the side of the first conductive portion near the second conductive semiconductor layer, where D1 > 0. In the second direction, the first side and the side of the second conductive portion closest to the first side have a second distance D2, where D2 > 0.
2. The back-contact solar cell according to claim 1, characterized in that, The first distance and the second distance satisfy the following relationship: D1≥D2.
3. The back-contact solar cell according to claim 1, characterized in that, The first distance D1 is between 0.005µm and 100µm.
4. The back-contact solar cell according to claim 1, characterized in that, The second distance D2 is between 0.001µm and 100µm.
5. The back-contact solar cell according to any one of claims 1 to 4, characterized in that, The second dielectric layer includes a first sub-part, a second sub-part, and a third sub-part; the first sub-part is disposed on the surface of the first conductive semiconductor layer away from the semiconductor substrate; the second sub-part is disposed on a first surface located in the second region; the third sub-part connects the first sub-part and the second sub-part; and the third sub-part covers the side surface of the dielectric layer and the side surface of the first conductive semiconductor layer; The second conductive semiconductor layer includes a fourth sub-part, a fifth sub-part, and a sixth sub-part; the fourth sub-part is disposed on the side of the first sub-part away from the semiconductor substrate; the fifth sub-part is disposed on the side of the second sub-part away from the semiconductor substrate; the sixth sub-part is disposed on the side of the third sub-part along the second direction, and the sixth sub-part connects the fourth sub-part and the fifth sub-part. Wherein, the surface of the fourth sub-part away from the first conductive semiconductor layer along the first direction is the first surface; the surface of the sixth sub-part away from the third sub-part along the second direction is the first side surface; In the second direction, there is a first distance D1 between the side of the fourth sub-part that is close to the first conductive part and the side of the first conductive part that is close to the fourth sub-part; In the second direction, there is a second distance D2 between the side of the sixth sub-part away from the third sub-part and the side of the second conductive part close to the sixth sub-part.
6. The back-contact solar cell according to claim 5, characterized in that, The orthogonal projection of the first conductive semiconductor layer onto the semiconductor substrate has a first length L1 in the second direction; The orthographic projection of the fourth sub-part onto the semiconductor substrate has a second length L2 in the second direction; the ratio of the second length L2 to the first length L1 is between (0.01 to 0.3):
1.
7. The back-contact solar cell according to claim 5, characterized in that, The first conductive portion is disposed on the surface of the first conductive semiconductor layer on the side away from the semiconductor substrate; the orthographic projection of the first conductive portion on the semiconductor substrate is located within the orthographic projection range of the first conductive semiconductor layer on the semiconductor substrate; and the orthographic projection of the first conductive portion on the semiconductor substrate and the orthographic projection of the fourth sub-part on the semiconductor substrate are spaced apart; the second conductive portion is disposed on the surface of the fifth sub-part on the side away from the semiconductor substrate; the orthographic projection of the second conductive portion on the semiconductor substrate is located within the orthographic projection range of the fifth sub-part on the semiconductor substrate; and the orthographic projection of the second conductive portion on the semiconductor substrate and the orthographic projection of the sixth sub-part on the semiconductor substrate are spaced apart; And / or, The back-contact solar cell further includes a first electrode and a second electrode, wherein the first electrode is disposed on the side of the first conductive portion away from the semiconductor substrate; the second electrode is disposed on the side of the second conductive portion away from the semiconductor substrate; and / or, The conductive layer includes a transparent conductive layer.
8. The back-contact solar cell according to claim 1, characterized in that, The first dielectric layer includes a tunneling oxide layer; and / or, The first conductive semiconductor layer includes a doped polycrystalline silicon layer; The second dielectric layer includes an intrinsic amorphous silicon layer; and / or, The second conductive semiconductor layer includes one of a doped amorphous silicon layer, a doped microcrystalline silicon layer, and a doped nanocrystalline silicon layer.
9. The back-contact solar cell according to claim 1, characterized in that, The back-contact solar cell further includes a passivation layer and an anti-reflection layer, wherein the passivation layer is disposed on the second surface; and the anti-reflection layer is disposed on the side of the passivation layer away from the semiconductor substrate.
10. A photovoltaic module, characterized in that, Including the back-contact solar cell as described in any one of claims 1 to 9.