A solar cell, a cell assembly and a photovoltaic system

Abstract

The utility model is suitable for photovoltaic technical field provides a kind of solar cell piece, battery component and photovoltaic system, this solar cell piece includes: semiconductor base, first polarity doped layer, second polarity doped layer, first grid line, second grid line and main grid;The back of semiconductor base includes several first area and second area of alternate arrangement, interval region is arranged between first area and second area, first area and second area are connected by connecting region, first polarity doped layer is stacked on first area, second polarity doped layer is stacked on second area, first polarity doped layer and second polarity doped layer composite contact in connecting region;First grid line is arranged in first area, and is electrically connected with first polarity doped layer, second grid line is arranged in second area, and is electrically connected with second polarity doped layer;Main grid is connected with first grid line and / or second grid line respectively;Connecting region is at least arranged in the at least one side edge position of the corresponding position of main grid.

Description

Technical Field

[0001] This utility model belongs to the field of photovoltaic technology, and in particular relates to a solar cell, a battery module and a photovoltaic system. Background Technology

[0002] In the field of solar cells, improving photoelectric conversion efficiency has always been a key goal pursued by the industry. Currently, traditional solar cells face many limitations that restrict efficiency improvement.

[0003] The current semiconductor substrate pattern structure of back-contact solar cells is suboptimal, and its back-side region division and connection methods fail to fully utilize the effects of each polarity doped layer. The layout of different polarity doped layers fails to effectively increase the amount of charge carriers generated, resulting in a limited number of collectable charge carriers. Moreover, the length and position of the grid lines cannot match the charge carrier generation, hindering efficient charge carrier collection and causing a significant loss of photogenerated charge carriers during transport. Ultimately, this limits the photoelectric conversion efficiency of the solar cell, restricting its competitiveness and large-scale application in the energy market. Therefore, innovative structural designs are urgently needed to solve these problems and improve the performance of solar cells. Utility Model Content

[0004] This invention provides a solar cell, a battery module, and a photovoltaic system, aiming to solve the problem of limited photoelectric conversion efficiency in existing technologies.

[0005] This invention is implemented as follows: a solar cell includes:

[0006] Semiconductor substrate, first polar doped layer, second polar doped layer, first gate line, second gate line and main gate;

[0007] The back side of the semiconductor substrate includes a plurality of alternately arranged first regions and second regions, with a gap region between the first regions and the second regions, and the first regions and the second regions are connected by a connection region. A first polar doped layer is stacked on the first region, and a second polar doped layer is stacked on the second region. The first polar doped layer and the second polar doped layer are in composite contact within the connection region.

[0008] The first gate line is disposed in the first region and electrically connected to the first polar doped layer, and the second gate line is disposed in the second region and electrically connected to the second polar doped layer;

[0009] The main grid is connected to the first grid line and / or the second grid line respectively;

[0010] The connection area is located at least on one side edge of the main gate at the corresponding position.

[0011] Optionally, the connecting areas are symmetrically arranged at the edges on both sides of the main gate.

[0012] Optionally, the connecting areas on both sides of the main gate extend to the opposite side.

[0013] Optionally, the connecting areas on both sides of the main gate extend to the opposite side for connection.

[0014] Optionally, the main gate extends along a first direction, and the first gate line and the second gate line extend along a second direction, which intersects the first direction.

[0015] Optionally, the transmission resistance R1 corresponding to the connection area and the reverse leakage resistance R2 corresponding to the solar cell are respectively, and the ratio A between R1 and R2 is greater than or equal to 0.1% and less than or equal to 80%.

[0016] Optionally, the first polar doped layer is a P-type doped layer, the second polar doped layer is an N-type doped layer, and the N-type doped layer covers the P-type doped layer within the connection region.

[0017] Optionally, the first polar doped layer is an N-type doped layer, the second polar doped layer is a P-type doped layer, and the P-type doped layer covers the N-type doped layer within the connection region.

[0018] This invention also provides a battery assembly, including the aforementioned solar cell.

[0019] This utility model also provides a photovoltaic system, including the above-mentioned battery components.

[0020] The beneficial effects achieved by this invention are as follows: The back side of the semiconductor substrate of the solar cell has alternating first and second regions, with an intermediate spacer region connected by a connecting region. Different polarity doped layers are stacked on different regions, and the first and second grid lines are electrically connected to their corresponding doped layers. The connecting region is located at the position corresponding to the main grid, increasing the area of ​​the doped layer adjacent to the main grid, enhancing the passivation effect of the solar cell, and thus improving the open-circuit voltage. Simultaneously, the increased length of the grid lines corresponding to the doped layers enhances the carrier collection capability and shortens the distance between different grid lines in two regions, reducing the carrier transport path and thus improving the fill factor. Therefore, the photoelectric conversion efficiency of the solar cell can be improved. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a region division on a solar cell provided by this utility model;

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure along the AA direction;

[0023] Figure 3 This is a schematic diagram of another region division on the solar cell provided by this utility model;

[0024] Figure 4 This is a schematic diagram of the BB-direction cross-sectional structure;

[0025] Figure 5 This is a schematic diagram of the structure of the solar cell provided by this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100, Semiconductor substrate; 110, First region; 111, First polar doped layer; 112, First tunneling layer; 120, Second region; 121, Second polar doped layer; 122, Second tunneling layer; 130, Spacer region; 140, Connecting region; 141, PSG layer; 150, Passivation layer;

[0028] 201, First gate line; 202, Second gate line; 203, Main gate. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.

[0030] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0035] This invention features a semiconductor substrate 100 with alternating first and second regions on its back side, separated by an intermediate region 130 and connected by a connecting region 140. Different polarity doped layers are stacked on the different regions, and the first and second grid lines are electrically connected to their corresponding doped layers. The connecting region 140 is positioned corresponding to the main grid 203, increasing the area of ​​the doped layer adjacent to the main grid 203, thus enhancing the passivation effect of the solar cell and improving its open-circuit voltage. Simultaneously, the increased length of the grid lines corresponding to the doped layers enhances carrier collection capability and shortens the distance between different grid lines in the two regions, reducing carrier transport paths and improving the fill factor. Therefore, this invention improves the photoelectric conversion efficiency of the solar cell.

[0036] Example 1

[0037] like Figure 1-5 As shown, this embodiment provides a solar cell, characterized in that it includes:

[0038] Semiconductor substrate 100, first polar doped layer 111, second polar doped layer 121, first gate line 201, second gate line 202 and main gate 203;

[0039] The back side of the semiconductor substrate 100 includes a plurality of alternately arranged first regions 110 and second regions 120, with a spacer region 130 between the first regions 110 and the second regions 120, and the first regions 110 and the second regions 120 are connected by a connecting region 140. A first polar doped layer 111 is stacked on the first region 110, and a second polar doped layer 121 is stacked on the second region 120. The first polar doped layer 111 and the second polar doped layer 121 are in composite contact within the connecting region 140.

[0040] The first gate line 201 is disposed in the first region 110 and electrically connected to the first polar doped layer 111; the second gate line 202 is disposed in the second region 120 and electrically connected to the second polar doped layer 121.

[0041] The main gate 203 is connected to the first gate line 201 and / or the second gate line 202 respectively;

[0042] The connection area 140 is located at least on one side edge of the main gate 203.

[0043] The solar cell is the core component of a solar cell module. It mainly consists of a semiconductor substrate 100 and various functional layers disposed on the semiconductor substrate 100. The semiconductor substrate 100 is the basic supporting structure of the solar cell, providing the physical carrier for the subsequent functional layers. The semiconductor substrate 100 has two main surfaces: a light-facing surface and a back-lighting surface. The light-facing surface directly faces the sunlight, while the back-lighting surface is the opposite side. The two surfaces are arranged opposite each other. The semiconductor substrate 100 can be made of silicon wafers such as monocrystalline silicon, polycrystalline silicon, microcrystalline silicon, or quasi-monocrystalline silicon. The quality of the silicon wafer directly determines the conversion efficiency of the solar cell. The surface types of the semiconductor substrate 100 include: textured surface, polished surface, or etched surface.

[0044] Two distinct regions, a first region 110 and a second region 120, are arranged alternately on the backlight surface of the semiconductor substrate 100. Specifically, a plurality of first regions 110 and a plurality of second regions 120 are arranged alternately along a first direction, and both the first regions 110 and 120 extend along a second direction, which intersects the first direction. The first regions 110 and 120 may be arranged alternately along the lateral direction of the semiconductor substrate 100 and both extend along the longitudinal direction; that is, the first direction may be the lateral direction of the back contact battery, and the second direction may be the longitudinal direction of the back contact battery, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions, for example, they may be the diagonal directions of the semiconductor substrate 100, and no specific limitation is made here. The first regions 110 and 120 do not overlap and are arranged adjacent to each other.

[0045] The spacer region 130 is disposed between the first region 110 and the second region 120 to isolate the first region 110 and the second region 120 and avoid electrical interference between the first region 110 and the second region 120. No conductive functional layer is disposed in the spacer region 130, that is, no electrical path is disposed in the spacer region 130. Typically, the spacer region 130 can be configured as a trench.

[0046] A first polar doped layer 111 is disposed in the first region 110, and a second polar doped layer 121 is disposed in the second region 120. The first polar doped layer 111 and the second polar doped layer 121 have opposite polarities. Specifically, the first polar doped layer 111 can be a P-type doped layer and the second polar doped layer 121 can be an N-type doped layer, or the first polar doped layer 111 can be an N-type doped layer and the second polar doped layer 121 can be a P-type doped layer. The first polar doped layer 111 and the second polar doped layer 121 form regions with different electrical characteristics, supporting the formation of PN junctions and the separation of charge carriers. In some embodiments, if the first polar doped layer 111 is a P-type doped layer, then the first polar doped layer 111 is a doped polycrystalline silicon layer, a doped microcrystalline silicon layer, or a doped amorphous silicon layer doped with group III elements such as boron, aluminum, or gallium. When the second polar doped layer 121 is an N-type doped layer, it is a doped polycrystalline silicon layer, a doped microcrystalline silicon layer, or a doped amorphous silicon layer doped with group V elements such as nitrogen, phosphorus, and arsenic. When the second polar doped layer 121 is a P-type doped layer, it is a doped polycrystalline silicon layer, a doped microcrystalline silicon layer, or a doped amorphous silicon layer doped with group III elements such as boron, aluminum, and gallium. When the first polar doped layer 111 is an N-type doped layer, it is a doped polycrystalline silicon layer, a doped microcrystalline silicon layer, or a doped amorphous silicon layer doped with group V elements such as nitrogen, phosphorus, and arsenic.

[0047] like Figure 5 As shown, a first grid line 201 is disposed within a first region 110, and the extension direction of the first grid line 201 is consistent with the extension direction of the first region 110. A second grid line 202 is electrically connected to a second polar doped layer 121; specifically, the second grid line 202 can be in direct contact with the second polar doped layer 121, or the second grid line 202 can be in contact with the second polar doped layer 121 through a conductive medium. A second grid line 202 is disposed within a second region 120, and the extension direction of the second grid line 202 is consistent with the extension direction of the second region 120. The second grid line 202 is electrically connected to the second polar doped layer 121; specifically, the second grid line 202 can be in direct contact with the second polar doped layer 121, or the second grid line 202 can be in contact with the second polar doped layer 121 through a conductive medium. The first grid line 201 and the second grid line 202 are used to collect the current generated inside the solar cell and conduct the current to an external circuit through other electrical paths. Understandably, the first gate line 201 and the second gate line 202 have good conductivity, which can effectively reduce resistance loss during current transmission.

[0048] The connecting region 140 connects the first region 110 and the second region 120. Specifically, the connecting region 140 may partially overlap with the first region 110, partially overlap with the second region 120, or overlap with both the first and second regions 110. Within the connecting region 140, the first polar doped layer 111 and the second polar doped layer 121 are in composite contact. Specifically, the first polar doped layer 111 may extend through the connecting region 140 into the second region 120 and form composite contact with the second polar doped layer 121 within the second region 120; the second polar doped layer 121 may extend through the connecting region 140 into the first region 110 and form composite contact with the first polar doped layer 111 within the first region 110; or the first polar doped layer 111 and the second polar doped layer 121 may each extend into the connecting region 140 and form composite contact within the connecting region 140.

[0049] Understandably, in this paper, "composite contact" refers to the absence of insulation between the first polar doped layer 111 and the second polar doped layer 121, where leakage current conducts and forms a leakage channel. Specifically, the first polar doped layer 111 and the second polar doped layer 121 may directly contact each other to form a leakage channel, or tunneling may be achieved through other dielectric layers to achieve the function of composite contact. No specific restrictions are imposed here.

[0050] When solar cells are working normally, they absorb light energy and generate current. When some solar cells are shaded or malfunction, they cannot generate current, but the other normally functioning solar cells continue to generate electricity. Because the solar cells are connected in series, current must be forced through the shaded solar cells. The resistance of the shaded solar cell increases, and according to Joule's law, this increases, consuming electrical energy and converting it into heat. Over time, the temperature of this solar cell continues to rise, and when it reaches a certain level, hot spots form. These hot spots can damage the performance and lifespan of the solar module.

[0051] The "composite contact" forms a leakage path similar to a bypass diode. This leakage path provides an additional path for current flow. Some current can bypass the problematic solar cell through the leakage path, thus preventing a large amount of current from concentrating in the hot spot area and reducing the heat output in that region. The leakage path also helps to equalize the voltage between solar cells. In the case of hot spots, the voltage across the shaded solar cell changes, creating a voltage difference between it and other normal solar cells. The presence of the leakage path allows the current to be regulated among different solar cells, resulting in a more balanced voltage across them. This reduces voltage differences between solar cells, further reducing the likelihood of hot spots and improving the stability and reliability of the entire solar module.

[0052] The main grid 203 is connected to the first grid line 201 and / or the second grid line 202. Specifically, the main grid 203 may be connected only to the first grid line 201, only to the second grid line 202, or connected to both the first and second grid lines 201. The main function of the main grid 203 is to further collect and transport the charge carriers collected from the first and second grid lines 201. Furthermore, the main grid 203 may also have a conductive connection structure, which can be a solder joint, pad, or pad point. This conductive connection structure is typically located at the end of the main grid 203 and is responsible for collecting the photocurrent generated on the cell surface, serving as a connection interface between the solar cell and the solder strip, conductive adhesive, or external wires, transferring electrical energy to the module circuit. The arrangement of the conductive connection structure can refer to existing methods, and this invention does not limit it.

[0053] The single main grid 203 is connected to a plurality of first grid lines 201 and / or the single main grid 203 is connected to a plurality of second grid lines 202. The setting direction of the main grid 203 is perpendicular to the setting direction of the grid lines (the first grid line 201 or the second grid line 202). Correspondingly, the corresponding position where the main grid 203 is set is an area with the same polarity as the grid lines connected by the main grid 203. For example, the first grid line 201 is set in the first area 110. When the main grid 203 is connected to the first grid line 201, the corresponding position of the main grid 203 is also the first area 110. Then, the shape of the first area 110 is similar to "丰". The vertical direction of "丰" is the first area 110 corresponding to the main grid 203, and the horizontal direction of "丰" is the first area 110 corresponding to the first grid line 201. The first area 110 and the second area 120 are arranged alternately, and there is an interval area 130 between the first area 110 and the second area 120. Then, the interval area 130 between the first area 110 corresponding to the main grid 203 and the second area 120 connects the interval area between the first area 110 corresponding to the first grid line 201 and the second area 120.

[0054] The connection area 140 is at least arranged at at least one side edge position of the area corresponding to the main grid 203, and the area connected to the connection area 140 will be correspondingly extended. Specifically, if the first grid line 201 is connected by the main grid 203, part of the corresponding position of the main grid 203 is the first area 110 and part is the connection area 140. A first-polarity doping layer 111 is arranged at the corresponding position of the main grid 203. The main grid 203 has a certain width. Then, the first-polarity doping layer 111 at the corresponding position of the main grid 203 has two relatively arranged side edges, and at least one side edge of the first-polarity doping layer 111 at the corresponding position of the main grid 203 contacts the extended second-polarity doping layer 121. The position where the first-polarity doping layer 111 and the second-polarity doping layer 121 contact is the connection area 140. The second grid line 202 is arranged on the second-polarity doping layer 121. Since the second-polarity doping layer 121 extends, the area of the second-polarity doping layer 121 is increased, more carriers can be generated, and at the same time, the length of the corresponding second grid line 202 is increased to collect the more generated carriers, which can increase the photoelectric conversion efficiency of the solar cell.

[0055] In a specific example, the length of the second-polarity doping layer 121 is extended, the length of the corresponding second grid line 202 is increased by 0.2 mm, the photoelectric conversion efficiency is increased by 0.05%, the open-circuit voltage is increased by 0.1%, and the fill factor is increased by 0.08%.

[0056] It should be noted that, as Figure 5As shown, the widths of the regions corresponding to the first gate line 201, the second gate line 202, and the main gate 203 are all greater than the widths of the first gate line 201, the second gate line 202, and the main gate 203 themselves. The width direction is perpendicular to its extension direction. For example, the width of the main gate 203 is less than the width of the region corresponding to the main gate 203. That is, in the width direction, the orthographic projection of the first gate line 201 cannot completely cover the orthographic projection of its corresponding first region 110. The regions corresponding to the first gate line 201, the second gate line 202, and the main gate 203 include the positions covered by the orthographic projections of the first gate line 201, the second gate line 202, and the main gate 203, as well as the positions not covered by the orthographic projections on either side of that position. In other words, when a cross-section is taken perpendicular to the extension direction of the first gate line 201, the second gate line 202, or the main gate 203, the region corresponding to that gate line 201, the second gate line 202, or the main gate 203 is located on the same cross-section.

[0057] The processing steps of the solar cell are as follows: a first polar doped layer 111 is formed on the entire back side of the semiconductor substrate 100; the first polar doped layer 111 corresponding to the second region 120 is etched away, and a second polar doped layer 121 is formed in the region other than the first region 110 (including the second region 120, the spacer region 130 and the connection region 140). At this time, the first polar doped layer 111 and the second polar doped layer 121 are in composite contact in the connection region 140 and the spacer region 130; the first polar doped layer 111 and the second polar doped layer 121 in the spacer region 130 are etched away to form a gap and isolate the first polar doped layer 111 and the second polar doped layer 121.

[0058] In this embodiment, the back side of the semiconductor substrate 100 of the solar cell has alternating first and second regions, with an intermediate spacer region 130 and connected by a connecting region 140. Different polarity doped layers are stacked on different regions, and the first and second gate lines are electrically connected to their respective doped layers. Compared to the connection region 140 being located at a position not corresponding to the main gate 203, the connection region 140 being located at a position corresponding to the main gate 203 increases the area of ​​the doped layer adjacent to the main gate 203, increases the passivation effect of the solar cell, and thus improves the open-circuit voltage of the solar cell. At the same time, the increased length of the gate lines corresponding to the doped layers enhances the carrier collection capability and shortens the distance between different gate lines in the two regions, reducing the carrier transport path and thus improving the fill factor. Therefore, the photoelectric conversion efficiency of the solar cell can be improved.

[0059] like Figure 3 As shown, in some embodiments, the connection area 140 is symmetrically arranged at the two sides of the main gate 203.

[0060] With the axis of the main gate 203 as the axis of symmetry, the connecting areas 140 on the left and right sides of the main gate 203 are mirror-symmetrically arranged on both sides of the axis of symmetry.

[0061] The symmetrical connection regions 140 ensure consistent carrier transport conditions on both sides of the main grid 203. This is analogous to two parallel roads with identical conditions, allowing carriers to converge uniformly towards the main grid 203 through the connection regions 140 on both sides. When a portion of the solar cell malfunctions, the symmetrical leakage channels on both sides can also provide an additional path for current flow with the same performance.

[0062] At the same time, the larger connection area of ​​140 mm means there are more locations where "composite contacts" can be formed, providing an additional path for current flow. This further reduces the likelihood of hot spots.

[0063] In some embodiments, the connection regions 140 on both sides of the main gate 203 extend to the opposite side.

[0064] With the axis of the main gate 203 as the central axis, the connecting areas 140 on both sides gradually extend to the opposite side from both sides of the central axis. The connecting areas 140, which were originally limited to the edges of the main gate 203, greatly increase the area covered by the connecting areas 140 by extending to the opposite side.

[0065] like Figure 1 As shown, in some embodiments, the connection regions 140 on both sides of the main gate 203 extend to the opposite side for communication. This further increases the area of ​​the connection regions 140.

[0066] In some embodiments, the first polar doped layer 111 is a P-type doped layer, the second polar doped layer 121 is an N-type doped layer, and within the connection region 140, the N-type doped layer covers the P-type doped layer.

[0067] Specifically, such as Figure 2 and Figure 4 As shown, a first tunneling layer 112 and a first polar doped layer 111 are stacked sequentially in the first region 110. The first polar doped layer 111 is a P-type doped layer. A second tunneling layer 122 and a second polar doped layer 121 are stacked sequentially in the second region. The second polar doped layer 121 is an N-type doped layer. The connecting region consists of the first tunneling layer 112, the first polar doped layer 111, the second tunneling layer 122, and the second polar doped layer 121 stacked sequentially. A PSG layer 141 can also be disposed between the first polar doped layer 111 and the second tunneling layer 122. A passivation layer 150 can also be disposed on the outermost layer of all functional layers. The first gate line 201 burns through the passivation layer 150 and is electrically connected to the first polar doped layer 111; the second gate line 202 burns through the passivation layer 150 and is electrically connected to the second polar doped layer 121.

[0068] In some embodiments, the first polar doped layer 111 is an N-type doped layer, the second polar doped layer 121 is a P-type doped layer, and within the connection region 140, the P-type doped layer covers the N-type doped layer.

[0069] Specifically, such as Figure 2 and Figure 4 As shown, a first tunneling layer 112 and a first polar doped layer 111 are sequentially stacked in the first region 110. The first polar doped layer 111 is an N-type doped layer. A second tunneling layer 122 and a second polar doped layer 121 are sequentially stacked in the second region. The second polar doped layer 121 is a P-type doped layer. The connecting region consists of the first tunneling layer 112, the first polar doped layer 111, the second tunneling layer 122, and the second polar doped layer 121, which are sequentially stacked. A PSG layer 141 can also be disposed between the first polar doped layer 111 and the second tunneling layer 122. A passivation layer 150 can also be disposed on the outermost layer of all functional layers. The first gate line 201 burns through the passivation layer 150 and is electrically connected to the first polar doped layer 111; the second gate line 202 burns through the passivation layer 150 and is electrically connected to the second polar doped layer 121.

[0070] Example 2

[0071] In some embodiments, the main gate 203 extends along a first direction, and the first gate line 201 and the second gate line 202 extend along a second direction, the second direction intersecting the first direction.

[0072] A plurality of first regions 110 and a plurality of second regions 120 are arranged alternately along a first direction, and both the first regions 110 and the second regions 120 extend along a second direction. A first gate line 201 is disposed in the first region 110, with the same extension direction as the first region 110, and a second gate line 202 is disposed in the second region 120, with the same extension direction as the second region 120. The main gate 203 is disposed in the same direction as the arrangement of the first regions 110 and the second regions 120, so as to facilitate connection with the first gate line 201 and / or the second gate line 202 and collect the charge carriers collected by the first gate line 201 and / or the second gate line 202.

[0073] Example 3

[0074] In some embodiments, the transmission resistance R1 corresponding to the connection region 140 and the reverse leakage resistance R2 corresponding to the solar cell are respectively, and the ratio A between R1 and R2 is greater than or equal to 0.1% and less than or equal to 80%. For example, the ratio can be set to 0.1%, 0.2%, 0.5%, 20%, 30%, 40%, etc., and the present invention does not limit this.

[0075] The transmission resistance corresponding to the connection region 140 is such that different parts within the connection are considered to have different resistances. Specifically, the resistance of the connection region 140 depends on the shape and material of each part within the connection region 140. The semiconductor materials of the first polar doped layer 111 and the second polar doped layer 121 within the connection region 140 themselves have a certain resistivity. When current is conducted through these materials, resistance is generated. Different doping concentrations and material properties lead to differences in resistance. For example, regions with higher doping concentrations have increased carrier concentrations, resulting in relatively better conductivity and potentially lower resistance; conversely, regions with lower doping concentrations will have relatively higher resistance. Furthermore, the geometry of each part of the connection region 140, such as its length and cross-sectional area, also affects the resistance; for example, a longer length and a smaller cross-sectional area result in a larger resistance.

[0076] In this embodiment, the transmission resistance corresponding to the connection region 140 is R1, and the reverse leakage resistance corresponding to the solar cell is R2. The ratio A between R1 and R2 is greater than or equal to 0.2% and less than or equal to 80%, meaning that the reverse leakage resistance R2 corresponding to the solar cell is much greater than the transmission resistance R1 corresponding to the connection region 140. When the solar cell is shaded, the reverse leakage current flows from one of the first polar doped layer 111 and the second polar doped layer 121 through the connection region 140 to the other. Since the reverse leakage resistance R2 corresponding to the solar cell is much greater than the transmission resistance R1 corresponding to the connection region 140, and the current flowing through R1 and R2 is the same during the reverse leakage process, the heat generated by the connection region 140 itself during the reverse leakage process is relatively low. This prevents the solar cell from experiencing a small reduction in local heat when a reverse bias voltage is applied due to the severe heat generation of the connection region 140 itself during the reverse leakage process. This effectively reduces the reverse breakdown voltage and hot spot risk of the solar cell, giving the solar cell a high resistance to burnout under reverse leakage conditions.

[0077] Example 4

[0078] This embodiment provides a battery assembly, including the aforementioned solar cell.

[0079] A battery module may include multiple solar cells, which can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current output. For example, the connection between the solar cells can be achieved by welding ribbons, or the connection between the battery strings can be achieved by busbars.

[0080] The battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film (not shown in the figures). The encapsulating film can be filled between the light-facing side of the solar cell and the photovoltaic glass, the back-facing side and the backsheet, and adjacent solar cells. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film can be EVA film or POE film, and the specific choice can be made according to the actual situation. There are no restrictions here.

[0081] Photovoltaic glass can be applied to the encapsulating film on the light-facing side of a solar cell. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell together, providing sealing, insulation, and waterproofing / moisture protection for the solar cell.

[0082] The backsheet can be attached to the encapsulating film on the back side of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0083] The beneficial effects of the battery module in this embodiment are equivalent to those of the solar cell described above, and will not be repeated here.

[0084] Example 5

[0085] This embodiment provides a photovoltaic system, including the aforementioned battery module.

[0086] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0087] The beneficial effects of the photovoltaic system in this embodiment are equivalent to the beneficial effects of the battery module described above, and will not be repeated here.

[0088] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A solar cell, characterized in that, include: Semiconductor substrate, first polar doped layer, second polar doped layer, first gate line, second gate line and main gate; The back side of the semiconductor substrate includes a plurality of alternately arranged first regions and second regions, with a gap region between the first regions and the second regions, and the first regions and the second regions are connected by a connection region. A first polar doped layer is stacked on the first region, and a second polar doped layer is stacked on the second region. The first polar doped layer and the second polar doped layer are in composite contact within the connection region. The first gate line is disposed in the first region and electrically connected to the first polar doped layer, and the second gate line is disposed in the second region and electrically connected to the second polar doped layer; The main grid is connected to the first grid line and / or the second grid line respectively; The connection area is located at least on one side edge of the main gate at the corresponding position.

2. The solar cell as described in claim 1, characterized in that, The connection areas are symmetrically arranged at the edges of both sides of the main gate.

3. The solar cell as described in claim 2, characterized in that, The connection areas on both sides of the main gate extend to the opposite side.

4. The solar cell as described in claim 3, characterized in that, The connecting areas on both sides of the main gate extend and connect to the opposite side.

5. The solar cell as described in claim 1, characterized in that, The main gate extends along a first direction, and the first gate line and the second gate line extend along a second direction, which intersects the first direction.

6. The solar cell as described in claim 1, characterized in that, The transmission resistance R1 corresponding to the connection area and the reverse leakage resistance R2 corresponding to the solar cell are such that the ratio A between R1 and R2 is greater than or equal to 0.1% and less than or equal to 80%.

7. The solar cell as described in claim 1, characterized in that, The first polar doped layer is a P-type doped layer, the second polar doped layer is an N-type doped layer, and in the connection region, the N-type doped layer covers the P-type doped layer.

8. The solar cell as described in claim 1, characterized in that, The first polar doped layer is an N-type doped layer, the second polar doped layer is a P-type doped layer, and in the connection region, the P-type doped layer covers the N-type doped layer.

9. A battery assembly, characterized in that, Includes the solar cell described in any one of claims 1-8.

10. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 9.

Images