A solar cell and photovoltaic module

Abstract

This invention discloses a solar cell and a photovoltaic module, relating to the field of photovoltaic technology, and addresses the problem of optimizing the conductive doping region of a solar cell. The solar cell includes a substrate, at least one side of which includes a first region, a second region, and a spacer region. The first and second regions are arranged alternately, and the first region is separated from the adjacent second region by the spacer region. The first region includes a first electrode placement area and a first bonding portion placement area connected together. The first electrode placement area is used to correspondingly place a first grid electrode, and the first bonding portion placement area is used to correspondingly place a first bonding portion electrically connected to the first grid electrode. In the alternating arrangement direction of the first and second regions, at least one side of the first bonding portion placement area protrudes relative to the first electrode placement area toward the adjacent spacer region, forming a first protruding portion.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more particularly to a solar cell and a photovoltaic module. Background Technology

[0002] Solar cells have doped conductive regions on their surface. Metal electrodes are placed on these regions to collect the current generated within them. This current is then collected and discharged through interconnects. The shape of the doped conductive regions affects the energy conversion efficiency of the solar cell. The patterning of the doped conductive regions in existing solar cells needs further optimization to improve their energy conversion efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a solar cell and a photovoltaic module that optimizes the patterning of the doped conductive region of the solar cell, thereby improving the energy conversion efficiency and the reliability of the solar cell.

[0004] In a first aspect, the present invention provides a solar cell, including a substrate, at least one side of the substrate including a first region, a second region and a spacer region, the first region and the second region being alternately arranged, and the first region being separated from an adjacent second region by the spacer region;

[0005] The first region includes a first electrode setting area and a first junction setting area connected together. The first electrode setting area is used to correspondingly set a first gate line electrode, and the first junction setting area is used to correspondingly set a first junction that is electrically connected to the first gate line electrode.

[0006] In the alternating arrangement direction of the first region and the second region, at least one side of the first joint setting region protrudes toward the adjacent interval region relative to the first electrode setting region, forming a first protruding portion.

[0007] When the above technical solution is adopted, the first region and the second region are arranged alternately on at least one side of the solar cell. The first region and the second region are both doped conductive regions of the cell. The first electrode setting area of ​​the first region is used to correspondingly set the first grid line electrode, and the first bonding part setting area of ​​the first region is used to correspondingly set the first bonding part. The first bonding part is electrically connected to the first grid line electrode, and the first grid line electrode is electrically connected to the interconnect through the first bonding part, so as to conduct the current collected in the first region. Because the size of the first bonding portion is typically adjustable within a limited range to ensure reliable conductive connection with the interconnecting components, the width range of the first region on the solar cell corresponding to the first bonding portion is also limited. To optimize the patterns of the first and second regions on the cell, reduce carrier recombination, and achieve better energy conversion efficiency, this application does not adjust the width range of the first bonding portion area. Instead, it adjusts only the width of the first electrode area on the first region where the first bonding portion is not located, thus narrowing the width of the first electrode area. The resulting pattern of the first region is such that at least one side of the first bonding portion area protrudes towards the adjacent spacing region relative to the first electrode area, forming a first protruding portion. This ensures the proper size of the first bonding portion area while reducing the overall coverage area of ​​the doped conductive regions by narrowing other locations. This optimizes the patterns of the first and second regions of the cell, reduces carrier recombination, and ultimately improves the energy conversion efficiency of the cell while ensuring reliable electrical connections.

[0008] In some possible implementations, in the alternating arrangement direction of the first region and the second region, the opposite sides of the first joint setting area protrude towards the adjacent interval region relative to the first electrode setting area, forming the first protruding portion. Thus, the pattern of the first region is such that both sides of the first joint setting area protrude outwards relative to the first electrode setting area. If the width of the first joint setting area is limited, both sides of the first electrode setting area can be narrowed inwards to optimize the pattern.

[0009] In some possible implementations, the second region includes a second electrode setting area and a second junction setting area connected together. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second junction setting area is used to correspondingly set the second junction connected to the second gate line electrode.

[0010] In the alternating arrangement direction of the first region and the second region, the widths of the second electrode setting area and the second joint setting area in the same second region are equal;

[0011] And / or, the distance between the first electrode setting area and the adjacent second electrode setting area is greater than the distance between the first protruding part of the first joint setting area and the adjacent second electrode setting area.

[0012] In the case of the above technical solution, the second electrode setting area of ​​the second region is used to correspondingly set the second grid line electrode, and the second joint setting area of ​​the second region is used to correspondingly set the second joint. The second joint is electrically connected to the second grid line electrode, and the second grid line electrode is electrically connected to the interconnect through the second joint. When the first region has a first protrusion, the second electrode setting area and the second joint setting area of ​​the same second region can be of equal width. That is, when the first electrode setting area of ​​the first region is narrowed, the distance between the first electrode setting area and the adjacent second electrode setting area is greater than the distance between the first protrusion of the first joint setting area and the adjacent second electrode setting area. By narrowing the first region and widening the second region, the pattern is optimized, thereby improving the energy conversion efficiency.

[0013] In some possible implementations, the second region includes a second electrode setting area and a second junction setting area connected together. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second junction setting area is used to correspondingly set the second junction connected to the second gate line electrode.

[0014] In the alternating arrangement direction of the first region and the second region, at least one side of the second electrode setting region is recessed relative to the second electrode setting region away from the adjacent interval region, forming a first recessed portion.

[0015] When the above technical solution is adopted, if the first electrode setting area in the first region is narrowed, the second electrode setting area in the second region can also be recessed inward to form a first recessed part. By locally narrowing the second electrode setting area in the second region, the pattern of the second region can be optimized as needed.

[0016] In some possible implementations, the first recessed portion matches the first protruding portion, and the first protruding portion and the first recessed portion are separated by the interval region;

[0017] And / or, in the alternating arrangement direction of the first region and the second region, the distance between the first electrode setting area and the adjacent second electrode setting area is greater than or equal to the distance between the first protruding part of the first joint setting area and the adjacent second electrode setting area.

[0018] When the above technical solution is adopted, if the first joint setting area in the first region has a first protruding part, in order to ensure that the distance between the first protruding part and the second electrode setting area in the adjacent second region meets the electrical isolation requirements, the first recessed part formed on the second region can be matched with the first protruding part, and there is a certain distance between the first recessed part and the first protruding part to achieve electrical isolation. The first electrode setting area and the second electrode setting area account for a large proportion of the first region and the second region, respectively. Therefore, ensuring that the distance between the first electrode setting area and the second electrode setting area is greater than or equal to the distance between the first protruding part of the first joint setting area and the adjacent second electrode setting area can reduce the overall leakage risk of the first region and the second region, and also ensure the distribution density of the first region and the second region.

[0019] In some possible implementations, the second region includes a second electrode setting area and a second junction setting area connected together. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second junction setting area is used to correspondingly set the second junction connected to the second gate line electrode.

[0020] In the alternating arrangement direction of the first region and the second region, at least one side of the second joint setting region protrudes toward the adjacent interval region relative to the second electrode setting region, forming a second protruding portion.

[0021] When the above technical solution is adopted, if the first joint setting area has a first protruding part, similarly, since the second joint is usually limited in size adjustment range to ensure reliable conductive connection with the interconnect, the width range of the second area on the solar cell corresponding to the second joint is also limited. In order to optimize the pattern of the first and second areas on the cell to obtain better energy conversion efficiency, this application does not adjust the width range of the second joint setting area, but only adjusts the width of the second electrode setting area on the second area where the second joint is not set, so that the width of the second electrode setting area is narrowed. The resulting pattern of the second area is such that at least one side of the second joint setting area protrudes towards the adjacent interval area relative to the second electrode setting area, forming a second protruding part. In this way, the size limitation of the second joint setting area can be eliminated, and the pattern of the first and second areas of the cell can be reasonably optimized to improve the energy conversion efficiency of the cell while ensuring the electrical connection reliability of the cell.

[0022] In some possible implementations, the first protruding portion and the adjacent second protruding portion are staggered in the alternating arrangement direction perpendicular to the first and second regions, and are separated by the interval region. Because the first and second protruding portions are staggered, correspondingly, the first joint area and the second joint area are also staggered. This facilitates the connection of the first joint portion in the first joint area with the interconnecting component, and facilitates the connection of the second joint portion in the second joint area with the external interconnecting component. This ensures that the connection areas of different interconnecting components are staggered, preventing short circuits caused by contact.

[0023] In some possible implementations, the projections of the first protrusion and the adjacent second protrusion on a straight line parallel to the alternating arrangement direction of the first and second regions overlap. This arrangement can further reduce the spacing between the first and second regions, thereby increasing the proportion of the first and second regions on the battery while meeting the spacing requirements, thus improving energy conversion efficiency and battery utilization.

[0024] In some possible implementations, in the alternating arrangement direction of the first and second regions, at least one side of the first electrode setting area is recessed relative to the adjacent spacing region, forming a second recessed portion. Similarly, when the second electrode setting area in the second region is narrowed, the first electrode setting area in the first region can also be recessed inward to form a second recessed portion, thereby optimizing the pattern of the first region as needed by locally narrowing the first electrode setting area in the first region.

[0025] In some possible implementations, the second recessed portion matches the second protruding portion, and the second protruding portion and the second recessed portion are separated by the interval region. Similarly, when the second joint setting area of ​​the second region has a second protruding portion, in order to ensure that the distance between the second protruding portion and the first electrode setting area of ​​the adjacent first region meets the electrical isolation requirements, the second recessed portion formed on the first region can be correspondingly matched with the second protruding portion, so that the distance there is equal to the distance between the second electrode setting area and the first electrode setting area.

[0026] In some possible implementations, in the alternating arrangement direction of the first and second regions, the protrusion width of the first protrusion relative to the same side of the first electrode placement area is 40μm to 80μm. And / or, the protrusion width of the second protrusion relative to the same side of the second electrode placement area is 40μm to 80μm. If the protrusion width is less than this range when the width of the first joint placement area remains essentially unchanged, it indicates that the narrowing of the first electrode placement area is small, and the optimization effect is not significant. If the protrusion width is greater than this range, it indicates that the narrowing of the first electrode placement area is large, affecting the current collection in the first region and requiring higher accuracy in the subsequent placement of the first electrode. The reasons for selecting the range of the second protrusion are the same as those for selecting the range of the first protrusion, and will not be repeated here.

[0027] In some possible implementations, the solar cell further includes the first grid electrode and the first junction portion; in the alternating arrangement direction of the first region and the second region, the ratio of the width of the first junction portion to the width of the first electrode placement area is 0.35 to 1.4. When the width ratio is less than 0.35, the width of the first junction portion is too small, which is not conducive to reliable connection with the interconnect; when the width ratio is greater than 1.4, the width of the first junction portion is too large, which is not conducive to electrical isolation and results in greater material consumption. And / or, the ratio of the width of the first grid electrode to the width of the first electrode placement area is 0.015 to 0.3. When the width ratio is less than 0.015, the width of the first grid electrode is too small, which is not conducive to current collection and results in higher resistance; when the width ratio is greater than 0.3, the width of the first grid electrode is too large, which is not conducive to electrical isolation and results in greater material consumption.

[0028] In some possible implementations, the solar cell further includes a second grid electrode and a second junction.

[0029] In the alternating arrangement direction of the first and second regions, the ratio of the width of the second joint to the width of the second electrode setting area is 0.2 to 0.7. When the width ratio is less than 0.2, the width of the second joint is too small, which is not conducive to reliable connection with the interconnect. When the width ratio is greater than 0.7, the width of the second joint is too large, which is not conducive to electrical isolation and results in greater material consumption. And / or, the ratio of the width of the second gate electrode to the width of the second electrode setting area is 0.012 to 0.12. When the width ratio is less than 0.012, the width of the second gate electrode is too small, which is not conducive to current collection and results in higher resistance. When the width ratio is greater than 0.12, the width of the second gate electrode is too large, which is not conducive to electrical isolation and results in greater material consumption.

[0030] Secondly, the present invention also provides a photovoltaic module, comprising:

[0031] A battery string, which is formed by electrically connecting several or more solar cells in any of the embodiments;

[0032] The interconnecting components are electrically connected to the junction of the solar cells;

[0033] And an encapsulation layer, used to cover the surface of the battery string.

[0034] The beneficial effects of photovoltaic modules in the second aspect can be found in the analysis of the beneficial effects in the first aspect and its various implementation methods, and will not be elaborated here. Attached Figure Description

[0035] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0036] Figure 1 This is a schematic diagram of the structure of a first region and a second region of a solar cell provided in an embodiment of the present invention;

[0037] Figure 2 This invention provides a schematic diagram of the structure of the first and second regions of another solar cell.

[0038] Figure 3 A schematic diagram of the structure of the first and second regions of another solar cell provided in an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of the structure of the first and second regions of another type of solar cell provided in an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the structure of a solar cell including electrodes, provided by an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of another solar cell including electrodes, provided as an embodiment of the present invention.

[0042] Reference numerals: 1 is the first region, 11 is the first joint area, 111 is the first protruding part, 12 is the first electrode area, 121 is the second recessed part, 2 is the second region, 21 is the second joint area, 211 is the second protruding part, 22 is the second electrode area, 221 is the first recessed part, 3 is the interval region, 4 is the second joint, 5 is the second grid line electrode, 6 is the first joint, and 7 is the first grid line electrode. Detailed Implementation

[0043] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0044] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0045] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0046] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", 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 invention 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 invention.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] Solar cells have doped conductive regions on their surface. Metal electrodes are placed on these doped conductive regions to collect the current generated within them. The metal electrodes are electrically connected through bonding elements and interconnects. Finally, the current is collected and discharged through the interconnects, which can be external solder strips or conductive layers. The shape of the doped conductive regions affects the energy conversion efficiency of the solar cell. The patterning of the doped conductive regions in existing solar cells needs further optimization to improve their energy conversion efficiency.

[0049] Firstly, such as Figure 1 and Figure 5 As shown, this embodiment of the invention provides a solar cell, including a substrate. At least one side of the substrate includes a first region 1, a second region 2, and a spacer region 3. The first region 1 and the second region 2 are arranged alternately, and the first region 1 is separated from the adjacent second region 2 by the spacer region 3. Both the first region 1 and the second region 2 are doped conductive regions of the solar cell. The first region 1 includes a first electrode setting region 12 and a first bonding region setting region 11 connected together. There can be multiple first electrode setting regions 12 and first bonding region setting regions 11, which are arranged alternately in the connecting direction. The first electrode setting region 12 is used to correspondingly set a first grid electrode 7, and the first bonding region setting region 11 is used to correspondingly set a first bonding region 6 electrically connected to the first grid electrode 7. The second region 2 includes a second electrode setting region 22 and a second bonding region setting region 21 connected together. There can also be multiple second electrode setting regions 22 and second bonding region setting regions 21, which are arranged alternately in the connecting direction. The second electrode setting region 22 is used to correspondingly set a second grid electrode 5, and the second bonding region setting region 21 is used to correspondingly set a second bonding region 4 connected to the second grid electrode 5. The first joint 6 and the second joint 4 can be joints, thickened sections of grid electrodes, sections of grid electrodes, or electrical connection points—any part capable of conductively connecting to the interconnecting element. The interconnecting element can be an external solder strip or a conductive layer, as long as it allows the battery cells to form a battery string through conductive connection. For example, the conductive layer can be a conductive layer used for a conductive backsheet. In the alternating arrangement direction of the first region 1 and the second region 2, Figure 1 In the first direction, at least one side of the first joint setting area 11 protrudes toward the adjacent interval area 3 relative to the first electrode setting area 12, forming a first protruding portion 111.

[0050] In the case of the above technical solution, the first region 1 and the second region 2 on at least one side of the solar cell are arranged alternately. The first electrode setting area 12 of the first region 1 is used to correspondingly set the first grid electrode 7, and the first joint setting area 11 of the first region 1 is used to correspondingly set the first joint 6. The first joint 6 is electrically connected to the first grid electrode 7, and the first grid electrode 7 is electrically connected to the interconnect through the first joint 6 to conduct current collected in the first region 1. Because the size of the first bonding portion 6 is usually limited to ensure reliable conductive connection with the interconnecting element, the overall width range of the first region 1 on the solar cell where the first bonding portion 6 is disposed is also limited. This limits the existing doped conductive region pattern setting scheme of the solar cell. In order to optimize the doped conductive region pattern on the cell and obtain better energy conversion efficiency, this application does not adjust the width range of the first bonding portion setting area 11 where the first bonding portion 6 is disposed, but only adjusts the width of the first electrode setting area 12 on the first region 1 where the first bonding portion 6 is not disposed, so that the width of the first electrode setting area 12 is narrowed. The resulting pattern of the first region 1 is such that at least one side of the first bonding portion setting area 11 protrudes towards the adjacent spacing area 3 relative to the first electrode setting area 12, forming a first protruding part 111. In this way, the size setting of the first bonding portion setting area 11 can be guaranteed, and by narrowing the doped conductive regions in other positions, the overall coverage area of ​​the doped conductive regions is reduced. The pattern of the doped conductive regions of the cell is reasonably optimized, carrier recombination is reduced, so as to improve the energy conversion efficiency of the cell and ensure the electrical connection reliability of the cell. Furthermore, even without considering the limitation of the width of the first junction area 11 by the width of the first junction 6, from the perspective of optimizing current collection, the width of the first junction area 11 can be set to be wider than the width of the first electrode area 12. Increasing the width of the first junction area 11 increases its area. The metal electrode collects current, and the junction collects the surrounding current on the one hand, and gathers the current discharged by the metal electrode on the other hand. The junction performs a dual function compared to the metal electrode. The first junction area 11 and the first electrode area 12 are doped conductive regions. The lateral transport capability of charge carriers in doped conductive regions is strong. Therefore, the width of the first junction area 11 is wider than the width of the first electrode area 12, which enhances the transport and collection of charge carriers around the junction. Narrowing the width of the first electrode area 12 is adapted to the current collection of the metal electrode part, reducing parasitic absorption, and ultimately achieving optimized collection of charge carriers on the substrate and improving current transmission efficiency.

[0051] Exemplarily, the solar cell can be a back-contact cell. A back-contact cell refers to a solar cell in which the light-facing surface of the cell wafer has no electrodes, and the positive and negative electrodes are both arranged on the backlight side of the cell wafer, which can reduce the shielding of the electrodes to the cell wafer, increase the short-circuit current of the cell wafer, and improve the energy conversion efficiency of the cell wafer. Correspondingly, the backlight side of the substrate of the back-contact cell includes a first region 1 and a second region 2. The conduction types of the first region 1 and the second region 2 are opposite, and they are separated by a spacer region 3. The first region 1 and the second region 2 can be alternating strip-shaped regions or alternating "abundant" - shaped regions in shape, forming an interdigitated pattern. The alternating arrangement direction of the first region 1 and the second region 2 can be defined as the alternating arrangement direction of each strip-shaped region, or the alternating arrangement direction of the strip-shaped regions corresponding to the fine grid electrodes of the interdigitated finger-shaped regions, such as Figure 1 the first direction shown in

[0052] Exemplarily, the solar cell can also not be a back-contact cell. One side of the substrate of the solar cell is the positive electrode, and the other side is the negative electrode. The first region 1 and the second region 2 are distributed on at least one side of the substrate. The conduction types of the first region 1 and the second region 2 located on the same side of the substrate are the same. The first region 1 and the second region 2 can be alternating strip-shaped regions. The alternating arrangement direction of the first region 1 and the second region 2 can be defined as the alternating arrangement direction of each strip-shaped region, such as Figure 1 the first direction shown in. The first region 1 and the second region 2 of the solar cell can be separated from each other and not connected; or they can be connected through a connection region, and the connection region is a doped conductive region with the same conduction type as the first region 1 and the second region 2.

[0053] All the above battery types can form a first protruding part 111 in the first joint setting area 11 of the first region 1 according to the above description, without being limited by the width of the first joint 6, and reasonably optimize the doped conductive region pattern to achieve the purpose of improving the energy conversion efficiency of the battery while ensuring the electrical connection reliability of the battery.

[0054] In the actual application process, the embodiments of the present invention do not make specific limitations on the material and conduction type of the substrate. Exemplarily, the above substrate can be a silicon substrate. Or, the above substrate can also be a germanium-silicon substrate, a germanium substrate, a gallium arsenide substrate or any other semiconductor material substrate. The conduction type of the substrate can be an N-type semiconductor substrate, a P-type semiconductor substrate or an intrinsic semiconductor substrate.

[0055] The first and second regions mentioned above are the doped conductive regions of the battery, and are provided with a doped semiconductor layer located on or within the substrate surface. In terms of materials, the doped semiconductor layer can be made of semiconductor materials such as silicon, germanium-silicon, germanium, or gallium arsenide. In terms of the arrangement of matter, the crystal phase of the first or second region can be amorphous, microcrystalline, nanocrystalline, single-crystal, or polycrystalline. In terms of doping concentration, the doping concentration of the doped semiconductor layer is higher than that of the substrate. In terms of conductivity type, for back-contact batteries, the conductivity type of the first or second region can be opposite to or the same as that of the substrate, as long as the conductivity types of the first and second regions are opposite. For non-back-contact batteries, the conductivity types of the first and second regions on one side of the substrate can be opposite to the conductivity type of the substrate; the conductivity types of the first and second regions on one side of the substrate can be the same as that of the substrate; or the conductivity types of the first and second regions on one side of the substrate can be opposite to the conductivity type of the substrate, while the conductivity types of the first and second regions on the other side of the substrate are the same as that of the substrate, as long as the conductivity types of the first and second regions on the same side are the same. As for the thickness of the first and second regions, it can be set according to actual needs, and no specific limit is made here.

[0056] In practical applications, the first region can be formed directly within the substrate surface or directly on the substrate. Alternatively, the back contact battery may also include a first passivation layer located between the substrate surface and the first region. In this case, the first passivation layer and the first region can form a selective contact structure to achieve chemical passivation of the substrate's back surface and selective collection of carriers of the corresponding conductivity type, reducing the carrier recombination rate on the back surface side and thus improving the photoelectric conversion efficiency of the back contact battery.

[0057] Specifically, the material of the first passivation layer can be determined based on the material of the first region and the type of selective contact structure formed by the first passivation layer and the first region in the actual application scenario, without specific limitations here.

[0058] For example, when the selective contact structure formed by the first passivation layer and the first region is a tunneling passivation contact structure, the first region is a doped polysilicon layer, and the first passivation layer is a tunneling passivation layer. The material of the tunneling passivation layer may include silicon oxide, silicon carbide, aluminum oxide, or titanium oxide, etc.

[0059] For example, when the selective contact structure formed by the first passivation layer and the first region is a heterogeneous contact structure, the first region is a doped amorphous silicon layer and / or a doped microcrystalline silicon layer, and the first passivation layer is an intrinsic amorphous silicon layer and / or an intrinsic microcrystalline silicon layer.

[0060] Regarding the second region mentioned above, it can be formed directly within the substrate surface or directly on the substrate surface. Alternatively, the back contact battery may also include a second passivation layer located between the substrate surface and the second region. In this case, the second passivation layer and the second region can constitute a selective contact structure to achieve chemical passivation of the substrate's back surface and selective collection of carriers of the corresponding conductivity type, reducing the carrier recombination rate on the back surface side and thus improving the photoelectric conversion efficiency of the back contact battery. Specifically, the material of the second passivation layer can refer to the material of the first passivation layer described above, and will not be repeated here.

[0061] Optionally, in some embodiments, in the alternating arrangement direction of the first region 1 and the second region 2, the opposite sides of the first joint setting area 11 protrude towards the adjacent interval region 3 relative to the first electrode setting area 12, forming a first protruding portion 111. Thus, the pattern of the first region 1 is such that both sides of the first joint setting area 11 protrude outward relative to the first electrode setting area 12. When the width of the first joint setting area 11 is limited, both sides of the first electrode setting area 12 can be narrowed inward to optimize the pattern.

[0062] like Figure 1 and Figure 5 As shown, in some embodiments, when the first joint setting area 11 has a first protrusion 111, in the alternating arrangement direction of the first region 1 and the second region 2, the widths of the second electrode setting area 22 and the second joint setting area 21 in the same second region 2 are equal, that is, the second electrode setting area 22 and the second joint setting area 21 in the same second region 2 have an equal width structure. At this time, since the first region 1 has a first protrusion 111 protruding into the adjacent interval region 3, the distance between the first electrode setting area 12 and the adjacent second electrode setting area 22 in the first region 1 and the adjacent second region 2 is greater than the distance between the first protrusion 111 of the first joint setting area 11 and the adjacent second electrode setting area 22.

[0063] Example 1: The width of the first joint setting area 11 is set to be wider than that of the first joint 6, and the width of the first electrode setting area 12 of the first region 1 is narrower than that of the first joint setting area 11, so that the first region 1 has a first protruding part 111. If the overall width of the second region 2 is consistent, that is, the second electrode setting area 22 and the second joint setting area 21 of the same second region 2 have the same width structure, then the gap area 3 between the first electrode setting area 12 of the first region 1 and the second region 2 is wider than the gap area 3 between the first joint setting area 11 and the second region 2. By ensuring that the width of the gap area 3 between the first electrode setting area 12 of the first region 1 and the second region 2 is larger, the leakage risk between the first region 1 and the second region 2 can be effectively reduced. On the other hand, increasing the width of the gap area 3, that is, increasing the area ratio of the gap area 3 on the substrate side, can improve the bifaciality of the cell and enhance the overall efficiency of the cell. Ensuring that the first bonding area 11 has a certain width ensures the reliability of the electrical connection between the first bonding area 6 and the interconnecting components, etc.; by narrowing the first electrode setting area 12 of the first region 1, the area ratio of the doped conductive region on one side of the substrate is reduced, parasitic absorption is reduced, the bifaciality of the solar cell is improved, and the overall efficiency of the solar cell is enhanced.

[0064] Example 2: The width of the first joint setting area 11 is set to be wider than the first joint 6, and the width of the first electrode setting area 12 of the first region 1 is narrower than the first joint setting area 11, so that the first region 1 has a first protrusion 111. The width of the first electrode setting area 12 in Example 2 is equal to the width of the first electrode setting area 12 in Example 1. On the basis that the overall width of the second region 2 in Example 1 remains the same, if the overall width of the second region 2 in Example 2 is increased compared to the overall width of the second region 2 in Example 1, the increased width is equal to the narrowing width of the first electrode setting area 12 compared to the first joint setting area 11 in Example 2. At this time, the width of the interval area 3 between the first electrode setting area 12 of the first region 1 and the second region 2 in Example 2 is narrower than the width of the interval area between the first electrode setting area 12 of the first region 1 and the second region 2 in Example 1. The width of the interval area 3 between the first joint setting area 11 and the second region 2 in Example 2 is smaller than the width of the interval area between the first joint setting area 11 and the second region 2 in Example 1. Taking a solar cell as a back-contact cell with an N-type substrate, a first region 1 being an N-type doped region and a second region 2 being a P-type doped region as an example, the width of the first electrode setting region 12 of the N-type doped region is smaller than that of the first junction setting region 11, giving the N-type doped region a first protrusion 111. Simultaneously, the P-type doped region has a uniform width structure, and its overall width is increased compared to the width of the second region 2 in Example 1. This increase is equal to the reduction in width of the first electrode setting region 12 compared to the first junction setting region 11, thereby increasing the PN junction area between the P-type doped region and the N-type substrate. This allows for the generation of more electron-hole pairs, thus increasing the current. Furthermore, the width of the first electrode setting region 12 of the N-type doped region is smaller than that of the first junction setting region 11, which has a limited width reduction, and the width of the spacer region 3 is smaller than that of the spacer region 3 in Example 1. This reduces the width of the base region composed of the N-type doped region and the spacer region 3, decreasing the lateral path of minority carriers to the PN junction region and improving the carrier collection probability. For all these reasons, this is beneficial for improving the energy conversion efficiency of the solar cell.

[0065] Of course, the substrate can also be a P-type substrate. The first region 1 can be a P-type doped region, and the second region 2 can be an N-type doped region. The width of the first electrode setting region 12 of the P-type doped region is smaller than that of the first junction setting region 11, giving the P-type doped region a first protrusion 111. Meanwhile, the N-type doped region has a uniform width structure, and its overall width is increased compared to the width of the second region 2 in Example 1. This increase is equal to the reduction in width of the first electrode setting region 12 compared to the first junction setting region 11. This also increases the PN junction area between the N-type doped region and the P-type substrate, generating more electron-hole pairs and thus increasing the current. Simultaneously, the width of the first electrode setting region 12 of the P-type doped region is smaller than that of the first junction setting region 11, which has a limited width reduction. The width of the spacer region 3 is also smaller than that of the spacer region 3 in Example 1, resulting in a smaller base region width composed of the P-type doped region and the spacer region 3. This reduces the lateral path of minority carriers to the PN junction region, increasing the carrier collection probability. This also contributes to improving the energy conversion efficiency of the solar cell.

[0066] Example 3: The width of the first joint setting area 11 is set to be wider than the first joint 6, and the width of the first electrode setting area 12 of the first region 1 is narrower than the first joint setting area 11, so that the first region 1 has a first protruding part 111. The width of the first electrode setting area 12 in Example 3 is equal to the width of the first electrode setting area 12 in Example 2. Based on the fact that the overall width of the second region 2 in Example 2 is equal and the width is increased, if the overall width of the second region 2 in Example 3 is further increased than the overall width of the second region 2 in Example 2, the width of the interval area 3 between the first electrode setting area 12 and the second region 2 in the first region 1 in Example 3 is smaller than the width of the interval area 3 between the first electrode setting area 12 and the second region 2 in the first region 1 in Example 2. The width of the interval area 3 between the first joint setting area 11 and the second region 2 in the first region 1 in Example 3 is smaller than the width of the interval area 3 between the first joint setting area 11 and the second region 2 in the first region 1 in Example 2. Taking a solar cell as a back-contact cell with an N-type substrate, a first region 1 being an N-type doped region and a second region 2 being a P-type doped region as an example, the width of the first electrode setting region 12 of the N-type doped region is smaller than that of the first junction setting region 11, so that the N-type doped region has a first protrusion 111. At the same time, the P-type doped region has a uniform width structure, and the overall width of the P-type doped region is larger than that of the second region 2 in Example 1. The increased width is greater than the reduced width of the first electrode setting region 12 compared to the first junction setting region 11 in Example 3. Therefore, compared to Example 2, Example 3 further increases the PN junction area between the P-type doped region and the N-type substrate, which can generate more electron-hole pairs and increase the current. Since the width of the spacer region 3 between the first electrode setting region 12 and the P-type doped region in Example 3 is smaller than that between the first electrode setting region 12 and the P-type doped region in Example 2, and since the width of the first electrode setting region 12 of the N-type doped region is reduced, the width of the spacer region 3 is also reduced. At this time, the width of the base region composed of the N-type doped region and the adjacent spacer region 3 is further reduced compared to Example 2. The lateral path of the minority carriers generated here to the PN junction region is further reduced, which further improves the carrier collection probability.

[0067] When the above technical solution is adopted, if the first region 1 has a first protrusion 111, the second electrode setting area 22 and the second joint setting area 21 in the same second region 2 can be of equal width. At this time, the distance between the first electrode setting area 12 and the adjacent second electrode setting area 22 is greater than the distance between the first protrusion 111 of the first joint setting area 11 and the adjacent second electrode setting area 22. By narrowing the first electrode setting area 12, narrowing the spacing area 3, or widening the second region 2, the pattern of the doped conductive area is optimized, thereby improving the energy conversion efficiency.

[0068] like Figure 2 , Figure 4 and Figure 5 As shown, based on any of the above embodiments, in this embodiment, when the first region 1 has a first protruding portion 111, in the alternating arrangement direction of the first region 1 and the second region 2, that is, in the first direction, at least one side of the second electrode setting region 22 is recessed relative to the second electrode setting region 22 away from the adjacent interval region 3, forming a first recessed portion 221. The number of first recessed portions 221 on the same second region 2 can be one or more.

[0069] When the above technical solution is adopted, when the first electrode setting area 12 of the first region 1 is narrowed, the second electrode setting area 22 of the second region 2 can also be recessed inward to form a first recessed part 221. By locally narrowing the second electrode setting area 22 of the second region 2, the pattern of the second region 1 can be optimized as needed.

[0070] Optionally, in this embodiment, the first recessed portion 221 and the first protruding portion 111 are positioned and matched in shape, the first protruding portion 111 is surrounded by the first recessed portion 221, and the first protruding portion 111 and the first recessed portion 221 are separated by a spacing region 3. At this time, in the alternating arrangement direction of the first region 1 and the second region 2, the distance between the first electrode setting area 12 and the adjacent second electrode setting area 22 can be equal to the distance between the first protruding portion 111 of the first joint setting area 11 and the adjacent second electrode setting area 22. Because the distance between the first region 1 and the second region 2 of the solar cell may have some errors in actual measurement or fluctuate within a certain range due to the influence of the surrounding structure, the term "equal to" in this application should cover the cases of complete equality and basic equality. Slightly greater than or slightly less than are both considered as basic equality. The case of basic equality is applied, and the judgment is made according to the actual measurement results. For example, 10% or 20% of the distance measurement value can be selected as the fluctuation space, and the difference within the range of 10% or 20% can be considered as a case of basic equality.

[0071] For example, the width of the first joint area 11 is set to be wider than the first joint 6, and the width of the first electrode area 12 of the first region 1 is narrower than the first joint area 11, so that the first region 1 has a first protrusion 111. If the width of at least a local portion of the second region 2 in this embodiment is increased compared to the width of the corresponding local position of the second region 2 in Example 1, the width of the second region 2 can be increased overall or partially. The part with the increased width usually corresponds to the part of the first electrode area 12 that is narrower than the first joint area 11 in this embodiment. The increased width of the second region 2 is equal to or greater than the narrower width of the first electrode area 12 that is narrower than the first joint area 11 in this embodiment, and the width of the gap region 3 between the first electrode area 12 of the first region 1 and the second region 2 is greater than that in Example 2. The width of the gap region 3 between the first electrode setting area 12 of the first region 1 and the second region 2 remains unchanged or is slightly reduced. A first recessed portion 221 is formed by recessing the second electrode setting area 22 of the second region 2 close to and corresponding to the first protruding portion 111. This makes the width of the gap region 3 between the first joint setting area 11 of the first region 1 and the first recessed portion 221 of the second region 2 greater than the width of the gap region 3 between the first joint setting area 11 and the first recessed portion 221 of the second region 2 in Example 2. This ensures that the width of the gap region 3 between the first region 1 and the second region 2 is equal. Compared with the case where the first protruding portion 111 and the first recessed portion 221 do not correspond, this ensures a sufficient gap distance and reduces the risk of the first joint setting area 11 and the second region 2 becoming conductive.

[0072] When the above technical solution is adopted, if the first joint setting area 11 of the first region 1 has a first protruding part 111, in order to ensure that the distance between the first protruding part 111 and the second electrode setting area 22 of the adjacent second region 2 meets the electrical isolation requirements, the first recessed part 221 formed in the second region 2 can be correspondingly matched with the first protruding part 111, so that the distance at that location is equal to the distance between the first electrode setting area 12 and the second electrode setting area 22. The above solution is only one way to achieve the distance between the first electrode setting area 12 and the second electrode setting area 22 being equal to the distance between the first protruding part 111 of the first joint setting area 11 and the adjacent second electrode setting area 22. It can also be achieved by adjusting the distribution density of the first region 1 and the second region 2, etc.

[0073] Optionally, in this embodiment, the first recessed portion 221 and the first protruding portion 111 are positioned and matched in shape, the first protruding portion 111 is surrounded by the first recessed portion 221, and the first protruding portion 111 and the first recessed portion 221 are separated by a gap region 3; at this time, in the alternating arrangement direction of the first region 1 and the second region 2, the distance between the first electrode setting area 12 and the adjacent second electrode setting area 22 can be smaller than the distance between the first protruding portion 111 of the first joint setting area 11 and the adjacent second electrode setting area 22.

[0074] For example, the width of the first joint area 11 is set to be wider than the first joint 6, and the width of the first electrode area 12 of the first region 1 is narrower than the first joint area 11, so that the first region 1 has a first protrusion 111. If the width of the second region 2 in this embodiment is at least partially increased compared to the width of the corresponding local position of the second region 2 in Example 1, the width of the second region 2 can be increased overall or partially. The part with the increased width usually corresponds to the part of the first electrode area 12 that is narrower than the first joint area 11 in this embodiment. The increased width of the second region 2 is greater than the narrower width of the first electrode area 12 that is narrower than the first joint area 11 in this embodiment, and the width of the gap area 3 between the first electrode area 12 of the first region 1 and the second region 2 is greater than... In Example 2, the width of the gap region 3 between the first electrode setting area 12 of the first region 1 and the second region 2 is reduced. By forming a first recessed portion 221 by recessing the second electrode setting area 22 of the second region 2 close to and corresponding to the first protruding portion 111, the width of the gap region 3 between the first joint setting area 11 of the first region 1 and the first recessed portion 221 of the second region 2 is increased or remains unchanged compared to the width of the gap region 3 between the first joint setting area 11 and the first recessed portion 221 of the second region 2 in Example 2. This ensures a sufficient gap distance, especially by increasing the distance between the first electrode setting area 12 and the second electrode setting area 22, which account for a larger proportion of the first region 1 and the second region 2, greatly reducing the risk of the first joint setting area 11 and the second region 2 becoming conductive.

[0075] When the above technical solution is adopted, if the first joint setting area 11 of the first region 1 has a first protruding part 111, in order to ensure that the distance between the first protruding part 111 and the second electrode setting area 22 of the adjacent second region 2 meets the electrical isolation requirements, the first recessed part 221 formed in the second region 2 can be correspondingly matched with the first protruding part 111, so that the distance at this location is smaller than the distance between the first electrode setting area 12 and the second electrode setting area 22. The above solution is only one way to achieve a distance between the first electrode setting area 12 and the second electrode setting area 22 that is greater than the distance between the first protruding part 111 of the first joint setting area 11 and the adjacent second electrode setting area 22. It can also be achieved by adjusting the distribution density of the first region 1 and the second region 2, etc.

[0076] like Figure 3 and Figure 4 As shown, based on any of the above embodiments, that is, based on the first protrusion 111 in the first region 1, the pattern of the second region 2 is further optimized. In the alternating arrangement direction of the first region 1 and the second region 2, that is, in the first direction, at least one side of the second joint setting area 21 protrudes relative to the second electrode setting area 22 toward the adjacent interval area 3 to form the second protrusion 211.

[0077] When the first bonding area 11 has a first protrusion 111, similarly, since the second bonding area 4 is usually limited in size adjustment range to ensure reliable conductive connection with the interconnect, the width range of the second region 2 on the solar cell corresponding to the second bonding area 4 is also limited. However, in order to optimize the pattern of the conductive doped region on the cell to obtain better energy conversion efficiency, this embodiment does not adjust the width range of the second bonding area 21 for setting the second bonding area 4, but only adjusts the width range of the second electrode setting area 22 on the second region 2 where the second bonding area 4 is not set. The width of the second electrode setting area 22 is adjusted separately to narrow the width of the second electrode setting area 22. The resulting pattern of the second region 2 is such that at least one side of the second bonding area 21 protrudes towards the adjacent interval area 3 relative to the second electrode setting area 22, forming a second protruding part 211. In this way, the size setting of the second bonding area 21 can be guaranteed, and by narrowing the doped conductive areas in other positions, the overall coverage area of ​​the doped conductive areas is reduced. The pattern of the conductive doped areas on the battery is reasonably optimized, and carrier recombination is reduced, so as to improve the energy conversion efficiency of the battery and ensure the electrical connection reliability of the battery. Furthermore, even without considering the limitation of the width of the second junction region 21 by the width of the second junction region 4, from the perspective of optimizing current collection, the width of the second junction region 21 can be set to be wider than the width of the second electrode region 22. Increasing the width of the second junction region 21 increases its area. The metal electrode collects current, and the junction collects the surrounding current on the one hand, and gathers the current discharged by the metal electrode on the other hand. The junction performs a dual function compared to the metal electrode. The second junction region 21 and the second electrode region 22 are doped conductive regions. The lateral transport capability of charge carriers in doped conductive regions is strong. Therefore, the width of the second junction region 21 is wider than the width of the second electrode region 22, which enhances the transport and collection of charge carriers around the junction. Narrowing the width of the second electrode region 22 is adapted to the current collection of the metal electrode part, reducing parasitic absorption, and ultimately achieving optimized collection of charge carriers on the substrate and improving current transport efficiency.

[0078] In this design, a second protrusion 211 is formed on one or both sides of the second joint area 21, and there may be one or more second protrusions 211 on each side. The pattern design for the second region 2 is also applicable to back-contact batteries and non-back-contact batteries, and its beneficial effects can be found in the description of the first region in the above embodiments, which will not be repeated here.

[0079] In some embodiments, in the direction perpendicular to the alternating arrangement of the first region 1 and the second region 2, i.e. Figure 3 and Figure 4In the second direction, which is perpendicular to the first direction, the first protruding part 111 and the adjacent second protruding part 211 are staggered, and their projections on a straight line parallel to the second direction do not overlap. The first protruding part 111 and the adjacent second protruding part 211 are separated by a spacing region 3. Since the first protruding part 111 and the second protruding part 211 are staggered, correspondingly, the first joint setting area 11 and the second joint setting area 21 are staggered. This facilitates the connection between the first joint 6 on the first joint setting area 11 and the multiple conductive areas arranged along the first direction on the outer solder strip or conductive layer extending along the first direction. At the same time, it facilitates the connection between the second joint 4 on the second joint setting area 21 and the multiple conductive areas arranged along the first direction on the outer solder strip or conductive layer extending along the first direction. This ensures that different solder strips or conductive areas are staggered in the second direction, avoiding short circuits or mutual interference.

[0080] For example, the first region 1 can be an N-type doped region, the second region 2 can be a P-type doped region, and both the first region 1 and the second region 2 can be strip-shaped regions. The first electrode setting region 12 is used to correspondingly set the first fine gate electrode, the first bonding region 11 is used to correspondingly set the first bonding region, the second electrode setting region 22 is used to correspondingly set the second fine gate electrode, and the second bonding region 21 is used to correspondingly set the second bonding region. The first region 1 and the second region 2 extend along the second direction. Multiple first bonding regions set on multiple first regions 1 and located in the same first direction are welded by a first solder strip. Multiple second bonding regions set on multiple second regions 2 and located in the same first direction are welded by a second solder strip. Since the first protrusion 111 and the second protrusion 211 are staggered in the second direction, the first bonding region and the second bonding region are staggered in the second direction, so that the first solder strip and the second solder strip are staggered, avoiding the contact between the first solder strip and the second solder strip leading to a short circuit. Alternatively, multiple first joints disposed on multiple first regions 1 and located in the same first direction are electrically connected through multiple first conductive areas arranged along the same first direction on the conductive layer, and multiple second joints disposed on multiple second regions 2 and located in the same first direction are electrically connected through multiple second conductive areas arranged along the same first direction on the conductive layer, so as to facilitate the partitioning of the first conductive area and the second conductive area.

[0081] The same applies to the interdigitated pattern of the first region 1 and the second region 2. For example, the first region 1 includes multiple strip regions corresponding to the first fine gate electrode and at least one strip region corresponding to the first main gate electrode, with the strip region corresponding to the first fine gate electrode perpendicular to the strip region corresponding to the first main gate electrode. Similarly, the second region 2 includes multiple strip regions corresponding to the second fine gate electrode and at least one strip region corresponding to the second main gate electrode, with the strip region corresponding to the second fine gate electrode perpendicular to the strip region corresponding to the second main gate electrode. The first direction refers to the alternating arrangement direction of the strip regions corresponding to the first and second fine gate electrodes, i.e., the extension direction of the first and second main gate electrodes. The second direction refers to the extension direction of the strip regions corresponding to the first and second fine gate electrodes. Each strip region corresponding to the first fine gate electrode has a first bonding area 11, where a first bonding portion can be disposed. Each strip region corresponding to the second fine gate electrode has a second bonding area 21, where a second bonding portion can be disposed. Of course, the first bonding area 11 can be located on the strip region corresponding to the first main gate electrode, and the second bonding area 21 can be located on the strip region corresponding to the second main gate electrode, as long as the first bonding portion and the second bonding portion are staggered in the second direction.

[0082] Optionally, in some embodiments, based on the above embodiments where the first protruding portion 111 and the second protruding portion 211 are staggered in the second direction, the projections of the first protruding portion 111 and the adjacent second protruding portion 211 on a straight line parallel to the alternating arrangement direction of the first region 1 and the second region 2 overlap. That is, the projections of the first protruding portion 111 and the adjacent second protruding portion 211 on a straight line parallel to the first direction overlap. This arrangement can further reduce the arrangement spacing of the first region 1 and the second region 2 in the first direction, and while meeting the spacing requirements of the interval region 3, can further increase the arrangement density of the first region 1 and the second region 2 on the battery, thereby improving energy conversion efficiency and battery utilization.

[0083] like Figure 4As shown, based on the embodiments above where the second region 2 has a second protruding portion 211, this embodiment further optimizes the first region 1. In the alternating arrangement direction of the first region 1 and the second region 2, i.e., in the first direction, at least one side of the first electrode setting area 12 is recessed relative to the first electrode setting area 12 away from the adjacent interval area 3, forming a second recessed portion 121. The number of second recessed portions 121 on the same first region 1 can be one or more. Similar to the reason for providing the first recessed portion 221 in the second region 2, the first electrode setting area 12 of the first region 1 can also be recessed inward to form a second recessed portion 121. By locally narrowing the first electrode setting area 12 of the first region 1, the pattern of the first region 1 can be optimized as needed.

[0084] Optionally, in this embodiment, the second recessed portion 121 and the second protruding portion 211 are positioned and matched in shape, the second protruding portion 211 is surrounded by the second recessed portion 121, and the second protruding portion 211 and the second recessed portion 121 are separated by the interval region 3. Similarly, when the second joint setting area 21 of the second region 2 has a second protruding portion 211, in order to ensure that the distance between the second protruding portion 211 and the first electrode setting area 12 of the adjacent first region 1 meets the electrical isolation requirements, the second recessed portion 121 formed in the recess on the first region 1 can be matched with the second protruding portion 211, so that the distance at that point is equal to the distance between the second electrode setting area 22 and the first electrode setting area 12. This ensures that the width of the interval region 3 between the first region 1 and the second region 2 is equal, which, compared to the case where the second protruding portion 211 and the second recessed portion 121 do not match, ensures a sufficient spacing distance and reduces the risk of conductivity between the second joint setting area 21 and the first region 1.

[0085] The patterns of the first region 1 and the second region 2 described in any of the above embodiments can be applied to the pattern optimization of solar cells with high-resistance dense grids. Dense-grid solar cells narrow the spacing of the metal grid lines, reducing recombination during electron movement perpendicular to the grid lines. Simultaneously, the overall area of ​​the fine grid lines on the cell increases, reducing series resistance, increasing the fill factor, and improving cell efficiency. The corresponding spacing between the first and second fine grid electrodes will decrease, and consequently, the widths of the first and second regions will decrease. At this time, while ensuring that the widths of the first and second joints meet reliability requirements, the first joint area and / or the second joint area can form a first protrusion and / or a second protrusion. Correspondingly, the second region can have a first recessed portion corresponding to the first protrusion, and the first region can have a second recessed portion corresponding to the second protrusion. The remaining positions are narrowed normally according to the grid spacing. The pattern optimization scheme in this application is more suitable for dense-grid solar cells, ensuring module reliability while further improving cell conversion efficiency.

[0086] like Figure 4 As shown, it should be noted that on the same surface of the solar cell, the first region 1 with the first protrusion 111 can exist in one or more of the following combinations: the second region 2 with the second protrusion 211, the second region 2 with the first recess 221, the first region 1 with the second recess 121, the second region 2 without the second protrusion 211, the second region without the first recess 221, and the first region 1 without the second recess 121. All of these can be regarded as pattern optimization of the conductive doped region.

[0087] like Figures 1-6 As shown, in some possible implementations, in the alternating arrangement direction of the first region 1 and the second region 2, i.e., in the first direction, the protrusion width of the first protrusion 111 on one side relative to the same side of the first electrode setting area 12 is 40μm to 80μm. Specifically, the protrusion width of the first protrusion 111 on one side can be 40μm, 50μm, 60μm, 70μm, 80μm, etc. The protrusion widths of the first protrusions 111 on both sides of the same first joint setting area 11 can be the same or different. When the protrusion widths are the same, the first electrode setting area 12 and the first joint setting area 11 are symmetrical in terms of the second direction. The distance between the first grid electrode 7 and the first joint 6 and the two sides can be the same, ensuring the uniformity of current collection and reducing the current transmission time.

[0088] Similarly, the protrusion width of the second protrusion 211 on one side relative to the same side of the second electrode setting area 22 is 40μm to 80μm. Specifically, the protrusion width of the second protrusion 211 on one side is 40μm, 50μm, 60μm, 70μm, 80μm, etc. The protrusion widths of the second protrusions 211 on both sides of the same second joint setting area 21 can be the same or different, with the same effect as the first protrusion 111, and will not be described again.

[0089] Thus, if the width of the first joint area 11 remains essentially unchanged, and the protrusion width is less than this range, it indicates that the narrowing of the first electrode area 12 is relatively small, resulting in an insignificant optimization effect. Conversely, if the protrusion width is greater than this range, it indicates that the narrowing of the first electrode area 12 is relatively large, affecting the current collection in the first region 1 and requiring higher precision in the subsequent setting of the first grid electrode 7. The reason for selecting the range of the second protrusion 211 is the same as that for selecting the range of the first protrusion 111, and will not be repeated here.

[0090] like Figure 5 and Figure 6 As shown, in some embodiments, the solar cell further includes a first grid electrode 7 and a first junction 6. In the alternating arrangement direction of the first region 1 and the second region 2, i.e., in the first direction, the ratio of the width of the first junction 6 to the width of the first electrode placement area 12 is 0.35 to 1.4. Specifically, the width ratio can be 0.35, 0.5, 0.64, 0.7, 0.9, 1.0, 1.2, 1.4, etc. A smaller width ratio means a relatively larger width of the first electrode placement area 12, and a larger width ratio means a relatively smaller width of the first electrode placement area 12. When the first junction 6 is a first junction, the width of the first junction is larger, and the corresponding width ratio is larger. When the first junction 6 is a thickened grid line segment, the width of the thickened grid line segment is smaller, and the corresponding width ratio is smaller. If the width ratio is less than 0.35, the width of the first joint 6 is too small, which is not conducive to a reliable connection with the interconnect. Alternatively, the width of the first electrode setting area 12 is too large, resulting in insufficient narrowing and insignificant optimization. If the width ratio is greater than 1.4, the width of the first joint 6 is too large, which is not conducive to electrical isolation and results in high material consumption. Alternatively, the width of the first electrode setting area 12 is too small, which is not conducive to carrier collection and increases the alignment accuracy requirement of the first gate electrode 7. It should be noted that the width of the first joint 6 is smaller than the width of the first joint setting area 11.

[0091] For example, in a back-contact solar cell, taking an N-type substrate, a first region 1 as an N-type doped region, and a second region 2 as a P-type doped region, the width of the first electrode setting region 12 in the N-type doped region is smaller than that of the first junction setting region 11, while the width of the P-type doped region is increased. This increases the area of ​​the PN junction region between the P-type doped region and the N-type substrate, generating more electron-hole pairs and thus increasing the current. Simultaneously, with the width of the first electrode setting region 12 in the N-type doped region decreasing and the width of the spacer region 3 remaining constant, the width of the base region composed of the N-type doped region and the spacer region 3 decreases. This reduces the lateral path of minority carriers to the PN junction region, improving the carrier collection probability. Therefore, for these reasons, a smaller width of the first electrode setting region 12 in the N-type doped region is more beneficial for improving the energy conversion efficiency of the solar cell. Correspondingly, a larger ratio of the width of the first junction 6 to the width of the first electrode setting region 12 is more beneficial for improving the energy conversion efficiency of the solar cell.

[0092] In some embodiments, the ratio of the width of the first gate electrode 7 to the width of the first electrode setting region 12 is 0.015 to 0.3, specifically 0.015, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, etc. When the width ratio is less than 0.015, the width of the first gate electrode 7 is too small, which is not conducive to current collection and results in a large resistance; or the width of the first electrode setting region 12 is too small, which is not conducive to pattern optimization. When the width ratio is greater than 0.3, the width of the first gate electrode 7 is too large, which is not conducive to electrical isolation and results in a large material consumption; or the width of the first electrode setting region 12 is too small, which is not conducive to carrier collection.

[0093] For example, the width of the first gate electrode 7 is 10μm to 35μm, specifically 10μm, 15μm, 20μm, 23μm, 24μm, 25μm, 26μm, 27μm, 30μm, 35μm, etc., and further can be 24μm to 27μm. The width of the first electrode setting area 7 is 150μm to 600μm, specifically 150μm, 220μm, 280μm, 300μm, 350μm, 400μm, 450μm, 500μm, 550μm, 600μm, etc.

[0094] like Figure 5 and Figure 6As shown, in some possible implementations, the solar cell further includes a second grid electrode 5 and a second junction 4. In the alternating arrangement direction of the first region 1 and the second region 2, i.e., in the first direction, the ratio of the width of the second junction 4 to the width of the second electrode placement area 22 is 0.2 to 0.7, specifically 0.2, 0.25, 0.3, 0.35, 0.49, 0.55, 0.7, etc. A smaller width ratio means a relatively larger width of the second electrode placement area 22, and a larger width ratio means a relatively smaller width of the second electrode placement area 22. When the second junction 4 is a second junction, its width is larger, resulting in a larger width ratio. When the second junction 4 is a thickened section of the grid line, its width is smaller, resulting in a smaller width ratio. If the width ratio is less than 0.2, the width of the second junction 4 is too small, which is not conducive to reliable connection with the interconnecting element. If the width ratio is greater than 0.7, the width of the second junction 4 is too large, which is not conducive to electrical isolation and results in greater material consumption. It should be noted that the width of the second joint 4 is smaller than the width of the second joint setting area 21.

[0095] For example, in a back-contact solar cell with an N-type substrate, a first region 1 being an N-type doped region, and a second region 2 being a P-type doped region, the width of the first electrode placement region 12 in the N-type doped region is smaller than that of the first junction region 11, while the width of the P-type doped region is increased. This increases the area of ​​the PN junction region between the P-type doped region and the N-type substrate, allowing for the generation of more electron-hole pairs and thus increasing the current. Therefore, for these reasons, a larger width of the second electrode placement region 22 in the P-type doped region is more beneficial for improving the energy conversion efficiency of the solar cell. Correspondingly, a smaller ratio of the width of the second junction 4 to the width of the second electrode placement region 22 is more beneficial for improving the energy conversion efficiency of the solar cell.

[0096] In some embodiments, the ratio of the width of the second gate electrode 5 to the width of the second electrode setting area 22 is 0.012 to 0.12, specifically 0.012, 0.013, 0.05, 0.08, 0.1, 0.12, etc. When the width ratio is less than 0.012, the width of the second gate electrode 5 is too small, which is not conducive to current collection and results in high resistance. When the width ratio is greater than 0.12, the width of the second gate electrode 5 is too large, which is not conducive to electrical isolation and results in high material consumption.

[0097] For example, the width of the second gate electrode 5 is 10μm to 35μm, specifically 10μm, 15μm, 20μm, 23μm, 24μm, 25μm, 26μm, 27μm, 30μm, 35μm, etc., and more specifically 24μm to 27μm. The width of the second electrode setting area 22 is 300μm to 800μm, specifically 300μm, 400μm, 450μm, 500μm, 550μm, 600μm, 650μm, 700μm, 750μm, 800μm, etc.

[0098] The following provides three sets of examples and three sets of comparative examples for parameter comparison:

[0099] Comparative Example 1: Measurements were taken of multiple solar cells using a back-contact cell. The substrate was an N-type substrate. The first region was an N-type doped region, the second region was a P-type doped region, the first region had an equal width structure, the second region had an equal width structure, and the spacer region had an equal width structure. The widths of the first region, the second region, and the spacer region in Comparative Example 1 can be defined as the original widths.

[0100] In Example 1, the solar cell is the same as that in Comparative Example 1. The width of the first junction area 11 in Example 1 is the same as the original width of the first region in Comparative Example 1, and the width of the second region 2 in Example 1 is the same as the original width of the second region in Comparative Example 1. The difference is that the first electrode area 12 in Example 1 is narrower than the first junction area 11, while the width of the first junction area 11 remains unchanged, so that the first region forms a first protrusion 111. At this time, the gap area 3 between the first electrode area 12 and the second region 2 is wider than the gap area in Comparative Example 1, and the width of the gap area 3 between the first junction area 11 and the second region 2 remains unchanged from the original width of the gap area in Comparative Example 1.

[0101] By comparing Example 1 and Comparative Example 1, the following parameter comparison table 1 is obtained:

[0102] Table 1. Parameter Comparison Table for Comparative Example 1 and Example 1

[0103]

[0104] By comparison, it was found that the short-circuit current was improved after the width of the first electrode setting region 12 of the N-type doped region in Example 2 was reduced.

[0105] Comparative Example 2, by measuring multiple solar cells, also uses back-contact cells, and is basically the same as the scheme of Comparative Example 1. The difference is that the overall width of the second region in Comparative Example 2 is increased compared to the original width of the second region in Comparative Example 1, and it is a structure of equal width. The width of the spacing region in Comparative Example 2 is decreased compared to the original width of the spacing region in Comparative Example 1. The decrease in width is equal to the increase in width of the second region in Comparative Example 2 compared to the second region in Comparative Example 1.

[0106] Example 2 is the same as the battery in Example 1, except that the overall width of the second region 2 in Example 2 is increased compared to the overall width of the second region 2 in Example 1. The increased width is equal to the narrowing of the first electrode setting area 12 from the first joint setting area 11. The width of the gap region 3 between the first electrode setting area 12 and the second region 2 in Example 2 is equal to the original width of the gap region in Comparative Example 1. The second region 2 forms a first recessed portion 221 corresponding to the first protrusion 111. The width of the gap region 3 between the first protrusion 111 and the second recessed portion 221 of the first joint setting area 11 is equal to the original width of the gap region in Comparative Example 1.

[0107] By comparing Example 2 and Comparative Example 2, the following parameter comparison table 2 is obtained:

[0108] Table 2. Parameter comparison table for Comparative Example 2 and Example 2

[0109]

[0110] By comparison, it was found that when the width of the first electrode setting region 12 of the N-type doped region in Example 2 is reduced and then correspondingly added to the P-type doped region to form the first recessed region 221 that matches the first protruding region 111, the conversion efficiency is improved, the fill factor is improved, and the short-circuit current is improved.

[0111] Comparative Example 3 is basically the same as the scheme in Comparative Example 2. The difference is that the overall width of the second region in Comparative Example 3 is further increased on the basis of the already increased width of the second region in Comparative Example 2, and the overall width of the interval region is further reduced on the basis of the already reduced width of the interval region in Comparative Example 2. The further reduction in width of the interval region is equal to the further increase in width of the second region.

[0112] Example 3 is basically the same as the scheme in Example 2. The difference is that, based on Example 2, the overall width of the second region in Example 3 is increased compared to the overall width of the second region in Example 2, and the overall width of the interval region in Example 3 is decreased compared to the overall width of the interval region in Example 2. The decrease in the width of the interval region is equal to the increase in the width of the second region. The second region 2 also forms a first recessed portion 221 corresponding to the first protruding portion 111. The width of the interval region 3 between the first region 1 and the second region 2 is equal.

[0113] By comparing Example 3 and Comparative Example 3, the following parameter comparison table 3 is obtained:

[0114] Table 3. Parameter comparison table for Comparative Example 3 and Example 3

[0115]

[0116] By comparison, it was found that when the width of the first electrode setting region 12 of the N-type doped region in Example 3 is reduced, it is correspondingly increased on the P-type doped region. When the width of the interval region 3 between the first region 1 and the second region 2 is reduced on the basis of the original width, and the reduced width is also increased to the overall width of the second region 2 and forms the first recessed region 221 that matches the first protruding part 111, the conversion efficiency is improved, the fill factor is improved, and the short-circuit current is improved.

[0117] It is evident that, overall, the patterning scheme in this application is beneficial to improving the energy conversion efficiency of the battery.

[0118] In a second aspect, embodiments of the present invention also provide a photovoltaic module, which includes a battery string, an interconnecting element, and an encapsulation layer; wherein, the battery string is formed by electrically connecting the solar cells provided in the first aspect and its various implementations; the interconnecting element is electrically connected to the junction of the solar cells provided in the first aspect and its various implementations, the junction being a first junction and a second junction, for current collection and assisting the solar cells in forming the battery string; the encapsulation layer is used to cover the surface of the battery string.

[0119] The beneficial effects of the photovoltaic modules in the embodiments of this application can be found in the analysis of the beneficial effects in the first aspect and its various implementations, which will not be repeated here.

[0120] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0121] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A solar cell, characterized in that, The substrate includes a first region, a second region, and a spacer region on at least one side. The first region and the second region are both doped conductive regions. The first region and the second region are arranged alternately, and the first region is separated from the adjacent second region by the spacer region. The first region includes a first electrode setting area and a first junction setting area connected together. The first electrode setting area is provided with a first gate line electrode, and the first junction setting area is provided with a first junction that is electrically connected to the first gate line electrode. The first junction is used to make a conductive connection with the interconnect. In the alternating arrangement direction of the first region and the second region, at least one side of the first joint setting region protrudes toward the adjacent interval region relative to the first electrode setting region, forming a first protruding portion.

2. The solar cell according to claim 1, characterized in that, In the alternating arrangement direction of the first region and the second region, the opposite sides of the first joint setting area protrude toward the adjacent interval area relative to the first electrode setting area, forming the first protruding portion.

3. The solar cell according to claim 1, characterized in that, The second region includes a second electrode setting area and a second junction setting area connected together. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second junction setting area is used to correspondingly set the second junction connected to the second gate line electrode. In the alternating arrangement direction of the first region and the second region, the widths of the second electrode setting area and the second joint setting area in the same second region are equal; And / or, the distance between the first electrode setting area and the adjacent second electrode setting area is greater than the distance between the first protruding part of the first joint setting area and the adjacent second electrode setting area.

4. The solar cell according to claim 1, characterized in that, The second region includes a second electrode setting area and a second junction setting area connected together. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second junction setting area is used to correspondingly set the second junction connected to the second gate line electrode. In the alternating arrangement direction of the first region and the second region, at least one side of the second electrode setting region is recessed relative to the second electrode setting region away from the adjacent interval region, forming a first recessed portion.

5. The solar cell according to claim 4, characterized in that, The first recessed portion matches the first protruding portion, and the first protruding portion and the first recessed portion are separated by the interval region; And / or, in the alternating arrangement direction of the first region and the second region, the distance between the first electrode setting area and the adjacent second electrode setting area is greater than or equal to the distance between the first protruding part of the first joint setting area and the adjacent second electrode setting area.

6. The solar cell according to claim 1, characterized in that, The second region includes a second electrode setting area and a second junction setting area connected together. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second junction setting area is used to correspondingly set the second junction connected to the second gate line electrode. In the alternating arrangement direction of the first region and the second region, at least one side of the second joint setting region protrudes toward the adjacent interval region relative to the second electrode setting region, forming a second protruding portion.

7. The solar cell according to claim 6, characterized in that, In the alternating arrangement direction perpendicular to the first region and the second region, the first protruding portion and the adjacent second protruding portion are staggered and separated by the interval region.

8. The solar cell according to claim 7, characterized in that, The projections of the first protruding portion and the adjacent second protruding portion on a straight line parallel to the alternating arrangement direction of the first region and the second region overlap.

9. The solar cell according to claim 6, characterized in that, In the alternating arrangement direction of the first region and the second region, at least one side of the first electrode setting region is recessed relative to the first electrode setting region away from the adjacent interval region, forming a second recessed portion.

10. The solar cell according to claim 9, characterized in that, The second recessed portion matches the second protruding portion, and the second protruding portion and the second recessed portion are separated by the interval region.

11. The solar cell according to any one of claims 6-10, characterized in that, In the alternating arrangement direction of the first region and the second region, the protrusion width of the first protrusion relative to the same side of the first electrode setting area is 40μm~80μm; And / or, the protrusion width of the second protrusion relative to the same side of the second electrode setting area is 40μm~80μm.

12. The solar cell according to any one of claims 1-10, characterized in that, In the alternating arrangement direction of the first region and the second region, the ratio of the width of the first joint to the width of the first electrode setting area is 0.35~1.4; And / or, the ratio of the width of the first gate electrode to the width of the first electrode setting area is 0.015 to 0.

3.

13. The solar cell according to any one of claims 3-10, characterized in that, The solar cell further includes a second grid electrode and a second junction portion; In the alternating arrangement direction of the first region and the second region, the ratio of the width of the second joint to the width of the second electrode setting area is 0.2 to 0.7; And / or, the ratio of the width of the second gate electrode to the width of the second electrode setting area is 0.012 to 0.

12.

14. A photovoltaic module, characterized in that, include: A battery string, wherein the battery string is formed by electrically connecting a plurality of solar cells as described in any one of claims 1 to 13; The interconnecting element is electrically connected to the junction of the solar cell; And an encapsulation layer that covers the surface of the battery string.

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