Solar cell and photovoltaic module

Abstract

The invention discloses a solar cell and a photovoltaic module, relates to the technical field of photovoltaics, and is used for solving the problem that a conductive doped region of the solar cell is to be optimized. The solar cell comprises a substrate, at least one surface of the substrate comprises first areas, second areas and spacing areas, the first areas and the second areas are alternately arranged, and the first areas and the adjacent second areas are spaced through the spacing areas; wherein the first area comprises a first electrode arrangement area and a first combination part arrangement area which are connected, the first electrode arrangement area is used for correspondingly arranging a first grid line electrode, and the first combination part arrangement area is used for correspondingly arranging a first combination part electrically connected with the first grid line electrode; in the alternate arrangement direction of the first areas and the second areas, at least one side of the first combination part arrangement area protrudes towards the adjacent interval area relative to the first electrode arrangement area, and a first protruding part is formed.

Description

Technical Field

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

[0002] The surface of a solar cell has a doped conductive region, and a metal electrode is disposed on the doped conductive region. The metal electrode is used to collect the current generated in the doped conductive region, and finally the current is collected and led out through an interconnecting member. The setting of doped conductive regions with different shapes affects the energy conversion efficiency of the solar cell. The patterning of the doped conductive region of the existing solar cell needs to be further optimized to improve the energy conversion efficiency of the solar cell. Summary of the Invention

[0003] An object of the present invention is to provide a solar cell and a photovoltaic module to optimize the patterning of the doped conductive region of the solar cell, and while improving the energy conversion rate, improve the reliability of the solar cell.

[0004] In a first aspect, the present invention provides a solar cell, including a substrate, at least one surface of the substrate including a first region, a second region, and a spacer region. The first region and the second region are arranged alternately, and the first region and the adjacent second region are spaced apart by the spacer region;

[0005] Wherein, the first region includes a first electrode setting area and a first bonding portion setting area connected to each other. The first electrode setting area is used to correspondingly set a first grid line electrode, and the first bonding portion setting area is used to correspondingly set a first bonding portion electrically connected to the first grid line electrode;

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

[0007] In the case of adopting the above technical solution, the first regions and the second regions are alternately arranged on at least one side of the solar cell. Both the first regions and the second regions are doped conductive regions of the cell. The first electrode setting region of the first region is used to correspondingly set the first grid line electrode. The first joint setting region of the first region is used to correspondingly set the first joint. The first joint is electrically connected to the first grid line electrode. The first grid line electrode is electrically connected to the interconnector through the first joint to export the current collected by the first region. Since the first joint is usually limited in the adjustable range of its size in order to ensure reliable electrical connection with the interconnector, correspondingly, the adjustable range of the width of the first region on the solar cell for correspondingly setting the first joint is limited. In order to optimize the patterns of the first regions and the second regions on the cell to reduce carrier recombination and obtain better energy conversion efficiency, in this application, the width range of the first joint setting region for setting the first joint is not adjusted, but only the width of the first electrode setting region on the first region where the first joint is not set is adjusted separately, so that the width of the first electrode setting region is narrowed. The pattern of the obtained first region is such that at least one side of the first joint setting region protrudes towards the adjacent spaced region relative to the first electrode setting region, forming a first protruding portion. In this way, the size setting of the first joint setting region can be ensured, and by narrowing the doped conductive regions in other positions, the overall coverage area of the doped conductive regions is reduced, reasonably optimizing the patterns of the first regions and the second regions of the cell, reducing carrier recombination, so as to achieve the purpose of improving the energy conversion efficiency of the cell while ensuring the electrical connection reliability of the cell.

[0008] In some possible implementation manners, in the alternating arrangement direction of the first regions and the second regions, the opposite sides of the first joint setting region respectively protrude towards the adjacent spaced region relative to the first electrode setting region, forming the first protruding portion. In this way, the pattern of the first region is such that both sides of the first joint setting region protrude outwards relative to the first electrode setting region. In the case where the narrowing of the width of the first joint setting region is limited, the two sides of the first electrode setting region can be narrowed inwards to optimize the pattern.

[0009] In some possible implementation manners, the second region includes a connected second electrode setting region and a second joint setting region. The second electrode setting region is used to correspondingly set the second grid line electrode. The second joint setting region is used to correspondingly set the second joint connected to the second grid line electrode;

[0010] In the alternating arrangement direction of the first regions and the second regions, the widths of the second electrode setting region and the second joint setting region of 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 adopting the above technical solution, the second electrode setting area in the second region is used to correspondingly set the second gate line electrode, and the second joint setting area in the second region is used to correspondingly set the second joint. The second joint is electrically connected to the second gate line electrode, and the second gate line electrode is electrically connected to the interconnecting member through the second joint. When there is a first protruding part in the first region, the second electrode setting area and the second joint setting area in the same second region can be of equal width structure. That is, when the first electrode setting area in the first region is narrowed, at this time, 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. By narrowing the first region and widening the second region, the pattern is optimized to achieve the purpose of improving the energy conversion efficiency.

[0013] In some possible implementation manners, the second region includes a connected second electrode setting area and a second joint setting area. The second electrode setting area is used to correspondingly set the second gate line electrode, and the second joint setting area is used to correspondingly set the second joint 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 area is recessed relative to the second electrode setting area away from the adjacent spaced area, forming a first recessed part.

[0015] In the case of adopting the above technical solution, when 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 is optimized as needed.

[0016] In some possible implementation manners, the first recessed part matches the first protruding part, and the first protruding part and the first recessed part are spaced apart by the spaced area;

[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] In the case of adopting the above technical solution, when the first joint part setting area in the first region has a first protruding part, in order to make the distance between the first protruding part and the second electrode setting area in the adjacent second region meet the electrical isolation requirement, the first recessed part formed by recessing on the second region can be correspondingly and matchedly set with the first protruding part. 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 respectively occupy a relatively large proportion in the first region and the second region. 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 part setting area and the adjacent second electrode setting area can not only reduce the overall leakage risk of the first region and the second region, but also ensure the distribution density of the first region and the second region.

[0019] In some possible implementation manners, the second region includes a connected second electrode setting area and a second joint part setting area. The second electrode setting area is used to correspondingly set a second gate line electrode, and the second joint part setting area is used to correspondingly set a second joint part 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 part setting area protrudes towards the adjacent spacer region relative to the second electrode setting area, forming a second protruding part.

[0021] In the case of adopting the above technical solution, when the first joint part setting area has a first protruding part, similarly, since the second joint part usually has a limited range of adjustable dimensions in order to ensure reliable electrical connection with the interconnecting member, correspondingly, the width range of the second region on the solar cell for correspondingly setting the second joint part is limited in adjustment. In order to optimize the patterns of the first region and the second region on the battery to obtain better energy conversion efficiency, the present application does not adjust the width range of the second joint part setting area for setting the second joint part, but only adjusts the width of the second electrode setting area on the second region where the second joint part is not set alone, narrowing the width of the second electrode setting area. The pattern of the obtained second region shows that at least one side of the second joint part setting area protrudes towards the adjacent spacer region relative to the second electrode setting area, forming a second protruding part. In this way, it is possible to not be limited by the size reduction limitation of the second joint part setting area, reasonably optimize the patterns of the first region and the second region of the battery, so as to achieve the purpose of improving the energy conversion efficiency of the battery while ensuring the electrical connection reliability of the battery.

[0022] In some possible implementation manners, in a direction perpendicular to the alternating arrangement direction of the first region and the second region, the first protruding portion and the adjacent second protruding portion are arranged in a staggered manner and are spaced apart by the spacing region. Since the first protruding portion and the second protruding portion are arranged in a staggered manner, correspondingly, the first joint portion setting region and the second joint portion setting region are arranged in a staggered manner, which facilitates the connection between the first joint portion disposed on the first joint portion setting region and the interconnecting member, and facilitates the connection between the second joint portion disposed on the second joint portion setting region and the external interconnecting member, so that different interconnecting member connection regions are staggered to avoid contact and short circuit.

[0023] In some possible implementation manners, 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. With such an arrangement, the arrangement pitch between the first region and the second region can be further reduced, and on the premise of meeting the spacing requirement of the spacing region, the proportion of the first region and the second region on the battery can be further increased, thereby improving the energy conversion efficiency and the battery utilization rate.

[0024] In some possible implementation manners, 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 spacing region, forming a second recessed portion. Similarly, when the second electrode setting region of the second region is narrowed, the first electrode setting region of the first region can also be recessed inward to form a second recessed portion, and by locally narrowing the first electrode setting region of the first region, the pattern of the first region can be optimized as needed.

[0025] In some possible implementation manners, the second recessed portion matches the second protruding portion, and the second protruding portion and the second recessed portion are spaced apart by the spacing region. Similarly, when the second joint portion setting region of the second region has a second protruding portion, in order to make the spacing between the second protruding portion and the first electrode setting region of the adjacent first region meet the electrical isolation requirement, the second recessed portion formed by recessing the first region can be correspondingly and matchingly arranged with the second protruding portion, so that the spacing at this position is equal to the spacing between the second electrode setting region and the first electrode setting region.

[0026] In some possible implementation manners, in the alternating arrangement direction of the first region and the second region, the protruding width of the first protruding portion on the same side as the first electrode setting region is 40 μm to 80 μm. And / or, the protruding width of the second protruding portion on the same side as the second electrode setting region is 40 μm to 80 μm. When the width of the first joint setting region remains basically unchanged, if the protruding width is less than this range, it means that the width of the narrowed first electrode setting region is small and the optimization effect is not obvious. If the protruding width is greater than this range, it means that the width of the narrowed first electrode setting region is large, which affects the current collection in the first region and requires higher setting accuracy for the subsequent first electrode. The reason for selecting the range of the second protruding portion is the same as that for selecting the range of the first protruding portion, and will not be elaborated here.

[0027] In some possible implementation manners, the solar cell further includes the first grid line electrode and the first joint; 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 region is 0.35 to 1.4. When the width ratio is less than 0.35, the width of the first joint is too small, which is not conducive to reliable connection with the interconnector. When the width ratio is greater than 1.4, the width of the first joint is too large, which is not conducive to electrical isolation and consumes more materials. And / or, the ratio of the width of the first grid line electrode to the width of the first electrode setting region is 0.015 to 0.3. When the width ratio is less than 0.015, the width of the first grid line electrode is too small, which is not conducive to current collection and has a large resistance. When the width ratio is greater than 0.3, the width of the first grid line electrode is too large, which is not conducive to electrical isolation and consumes more materials.

[0028] In some possible implementation manners, the solar cell further includes a second grid line electrode and a second joint;

[0029] 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 region 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 interconnector. 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 consumes more materials. And / or, the ratio of the width of the second grid line electrode to the width of the second electrode setting region is 0.012 to 0.12. When the width ratio is less than 0.012, the width of the second grid line electrode is too small, which is not conducive to current collection and has a large resistance. When the width ratio is greater than 0.12, the width of the second grid line electrode is too large, which is not conducive to electrical isolation and consumes more materials.

[0030] In a second aspect, the present invention further provides a photovoltaic module, including:

[0031] A battery string, which is formed by electrically connecting a plurality of solar cells in any of the above embodiments;

[0032] An interconnecting member, which is electrically connected to the joint part of the solar cell;

[0033] And a packaging layer, which is used to cover the surface of the battery string.

[0034] For the beneficial effects of the photovoltaic module in the second aspect, reference can be made to the analysis of the beneficial effects in the first aspect and its various implementation manners, which will not be elaborated here. Description of the Drawings

[0035] The drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0036] Figure 1 It is a schematic structural diagram of a first region and a second region of a solar cell provided by an embodiment of the present invention;

[0037] Figure 2 It is a schematic structural diagram of a first region and a second region of another solar cell provided by an embodiment of the present invention;

[0038] Figure 3 It is a schematic structural diagram of a first region and a second region of yet another solar cell provided by an embodiment of the present invention;

[0039] Figure 4 It is a schematic structural diagram of a first region and a second region of still another solar cell provided by an embodiment of the present invention;

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

[0041] Figure 6 It is a schematic structural diagram of another solar cell including electrodes provided by an embodiment of the present invention.

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

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, 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 only used to explain the present invention and are not used to limit the present invention.

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

[0045] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined. The meaning of "several" is one or more, unless otherwise specifically defined.

[0046] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0047] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] The surface of the solar cell has a doped conductive region, and a metal electrode is disposed on the doped conductive region. The metal electrode is used to collect the current generated in the doped conductive region. The metal electrode is electrically connected through a bonding portion and an interconnecting member, and finally the current is collected and led out through the interconnecting member. The interconnecting member can be an external solder strip or a conductive layer. The setting of doped conductive regions with different shapes affects the energy conversion efficiency of the solar cell. The patterning of the doped conductive regions of the existing solar cells needs to be further optimized to improve the energy conversion efficiency of the solar cell.

[0049] In a first aspect, as Figure 1 and Figure 5 shown, an embodiment of the present 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 and the adjacent second region 2 are spaced apart by the spacer region 3. Both the first region 1 and the second region 2 are doped conductive regions of the solar cell. Among them, the first region 1 includes a connected first electrode setting area 12 and a first joint setting area 11. The first electrode setting area 12 and the first joint setting area 11 can be multiple, and are arranged alternately in the connected direction. The first electrode setting area 12 is used to correspondingly set the first grid line electrode 7, and the first joint setting area 11 is used to correspondingly set the first joint 6 electrically connected to the first grid line electrode 7. The second region 2 includes a connected second electrode setting area 22 and a second joint setting area 21. The second electrode setting area 22 and the second joint setting area 21 can also be multiple, and are alternately arranged in the connected direction. The second electrode setting area 22 is used to correspondingly set the second grid line electrode 5, and the second joint setting area 21 is used to correspondingly set the second joint 4 connected to the second grid line electrode 5. Among them, the first joint 6 and the second joint 4 can be joints, thickened segments of grid line electrodes, a certain segment of grid line electrodes or electrical connection points and other parts that can be conductively connected to the interconnector. Among them, the interconnector can be an external solder tape or a conductive layer, as long as it can form a battery string by conductive connection of the battery chips. For example, the conductive layer can be the conductive layer used for the conductive backplane. In the alternate arrangement direction of the first region 1 and the second region 2, Figure 1 the middle is the first direction, and at least one side of the first joint setting area 11 protrudes towards the adjacent spacer region 3 relative to the first electrode setting area 12, forming a first protruding part 111.

[0050] When the above technical solution is adopted, the first area 1 and the second area 2 on at least one side of the solar cell are arranged alternately, the first electrode setting area 12 of the first area 1 is used to correspondingly set the first gate line electrode 7, the first combining portion setting area 11 of the first area 1 is used to correspondingly set the first combining portion 6, the first combining portion 6 is electrically connected to the first gate line electrode 7, and the first gate line electrode 7 is conductively connected to the interconnection member through the first combining portion 6 to conduct the current collected by the first area 1. In order to ensure reliable conductive connection with the interconnection member, the first bonding portion 6 usually has a limited adjustable range of size. Accordingly, the overall width range of the first region 1 on the solar cell corresponding to the first bonding portion 6 is limited, resulting in a limited setting scheme of the doped conductive region pattern of the existing solar cell. In order to optimize the doped conductive region pattern on the cell to obtain better energy conversion efficiency, the present application does not adjust the width range of the first bonding portion setting area 11 for setting the first bonding portion 6, 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 set, so that the width of the first electrode setting area 12 is narrowed. The obtained pattern of the first region 1 is characterized in that at least one side of the first bonding portion setting area 11 protrudes relative to the first electrode setting area 12 toward the adjacent spacing area 3 to form a first protruding portion 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 at other positions, the coverage area of the overall doped conductive region is reduced, the pattern of the doped conductive region of the cell is reasonably optimized, and carrier recombination is reduced, so as to achieve the purpose of improving the energy conversion efficiency of the cell and ensuring the electrical connection reliability of the cell. In addition, even if the factor that the width range of the first combination part setting area 11 is limited by the width of the first combination part 6 is not considered, from the perspective of optimizing current collection, the width of the first combination part setting area 11 can also be set to be wider than the width of the first electrode setting area 12. The width of the first combination part setting area 11 increases, so that the area of the first combination part setting area 11 increases, and the metal electrode collects current. The combination collects the surrounding current on the one hand, and collects the metal electrode output on the other hand. The combination has a dual function compared to the metal electrode. The first combination part setting area 11 and the first electrode setting area 12 are doped conductive areas. The doped conductive areas have a strong lateral carrier transmission ability. Therefore, the width of the first combination part setting area 11 is wider than the width of the first electrode setting area 12, which enhances the carrier transmission and collection around the combination, and narrows the width of the first electrode setting area 12 to adapt to the current collection of the metal electrode part, reduce parasitic absorption, and ultimately achieve optimized carrier collection on the substrate and improve 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 disposed 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 spaced apart by a spacer region 3. The first region 1 and the second region 2 can be alternating strip-shaped regions or alternating "abundant" character-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 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 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; they can also be connected by 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 of the above cell 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 optimizing the doped conductive region pattern to achieve the purpose of improving the energy conversion efficiency of the cell while ensuring the electrical connection reliability of the cell.

[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. Alternatively, the above substrate can also be a substrate of any semiconductor material such as a germanium-silicon substrate, a germanium substrate, or a gallium arsenide 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 above-mentioned first region and second region are doped conductive regions of the battery, and are provided with a doped semiconductor layer on the surface of the substrate or a doped semiconductor layer within the surface of the substrate. In terms of materials, the materials of the above-mentioned doped semiconductor layer can be semiconductor materials such as silicon, silicon germanium, germanium or gallium arsenide. In terms of the arrangement form of substances, the crystal phase of the first region or the second region can be amorphous, microcrystalline, nanocrystalline, single crystal or polycrystalline, etc. In terms of the doping concentration, the doping concentration of the doped semiconductor layer is higher than that of the substrate. In terms of the conduction type, for a back-contact battery, the conduction type of the first region or the second region can be opposite to that of the substrate, or the same as that of the substrate, as long as it is ensured that the conduction types of the first region and the second region are opposite. For a non-back-contact battery, the conduction types of the first region and the second region on one side of the substrate can be opposite to that of the substrate; the conduction types of the first region and the second region on one side of the substrate can be the same as that of the substrate; it is also possible that the conduction types of the first region and the second region on one side of the substrate are opposite to that of the substrate, and the conduction types of the first region and the second region on the other side of the substrate are the same as that of the substrate, as long as it is ensured that the conduction types of the first region and the second region on the same side are the same. As for the thicknesses of the first region and the second region, they can be set according to actual requirements and are not specifically limited here.

[0056] In the actual application process, the first region can be directly formed within the surface of the substrate or directly formed on the substrate. Alternatively, the back-contact battery further includes a first passivation layer located between the surface of the substrate 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 backlight side of the substrate and selective collection of carriers of the corresponding conduction type, reduce the carrier recombination rate on the backlight side, and facilitate improving the photoelectric conversion efficiency of the back-contact battery.

[0057] Specifically, the material of the above-mentioned first passivation layer can be determined according to the material of the first region and the type of the selective contact structure formed by the first passivation layer and the first region in the actual application scenario, and is not specifically limited 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 materials of the tunneling passivation layer can include materials such as silicon oxide, silicon carbide, aluminum oxide or titanium oxide.

[0059] Another example: when the selective contact structure formed by the first passivation layer and the first region is a heterojunction 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 above-mentioned second region, the second region can be directly formed within the substrate surface or directly formed on the substrate surface. Alternatively, the back contact battery further includes 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 form a selective contact structure to achieve chemical passivation of the backlight surface of the substrate and selective collection of carriers of the corresponding conductivity type, reduce the carrier recombination rate on the backlight surface side, and facilitate improving the photoelectric conversion efficiency of the back contact battery. Specifically, the material of the above-mentioned second passivation layer can refer to the material of the first passivation layer described above, which will not be elaborated here.

[0061] Optionally, in some embodiments, in the alternating arrangement direction of the first region 1 and the second region 2, on opposite sides of the first joint setting area 11, they respectively protrude towards the adjacent spacer area 3 relative to the first electrode setting area 12, forming a first protruding part 111. Thus, the pattern of the first region 1 shows that both sides of the first joint setting area 11 protrude outwards relative to the first electrode setting area 12. When the narrowing of the width of the first joint setting area 11 is limited, the two sides of the first electrode setting area 12 can be narrowed inwards to optimize the pattern.

[0062] As Figure 1 and Figure 5 shown, in some embodiments, when the first protruding part 111 is formed in the first joint setting area 11, 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 of the same second region 2 are equal, that is, the second electrode setting area 22 and the second joint setting area 21 of the same second region 2 are of an equal-width structure. At this time, since the first region 1 has the first protruding part 111 protruding towards the adjacent spacer area 3, in the first region 1 and the adjacent second region 2, 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 protruding part 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 part setting area 11 is set to be wider than that of the first joint part 6, and the first electrode setting area 12 of the first area 1 is narrowed compared with the first joint part setting area 11, so that the first area 1 has a first protruding part 111. If the overall width of the second area 2 remains the same, that is, the second electrode setting area 22 and the second joint part setting area 21 of the same second area 2 are of equal width structure. At this time, the spacing area 3 between the first electrode setting area 12 of the first area 1 and the second area 2 is wider than the spacing area 3 between the first joint part setting area 11 and the second area 2. By ensuring the width of the spacing area 3 between the first electrode setting area 12 of the first area 1, which accounts for a relatively large proportion, and the second area 2, on the one hand, the leakage risk between the first area 1 and the second area 2 can be effectively reduced. On the other hand, increasing the width of part of the spacing area 3, that is, increasing the area ratio of the spacing area 3 on one side of the substrate, can improve the bifaciality of the solar cell and enhance the overall efficiency of the solar cell. Ensuring that the first joint part setting area 11 has a certain width ensures the electrical connection reliability between the first joint part 6 and the interconnector, etc. on it; by narrowing the first electrode setting area 12 of the first area 1, the area ratio of the doped conductive area on one side of the substrate is reduced, the 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 part setting area 11 is set to be wider than that of the first joint part 6. The first electrode setting area 12 of the first region 1 is narrowed compared to the first joint part 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 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 width by which the first electrode setting area 12 in Example 2 is narrowed compared to the first joint part setting area 11. At this time, the width of the spacer region 3 between the first electrode setting area 12 of the first region 1 and the second region 2 in Example 2 is narrowed compared to the width of the spacer region between the first electrode setting area 12 of the first region 1 and the second region 2 in Example 1. The width of the spacer region 3 between the first joint part setting area 11 of the first region 1 and the second region 2 in Example 2 is reduced compared to the width of the spacer region between the first joint part setting area 11 of the first region and the second region 2 in Example 1. Taking a solar cell as a back contact cell, with the substrate being an N-type substrate, the first region 1 being an N-type doped region, and the second region 2 being a P-type doped region as an example, the width of the first electrode setting area 12 of the N-type doped region is reduced compared to the first joint part setting area 11, so that the N-type doped region has a first protruding part 111. At the same time, the P-type doped region has an equal-width structure, and the overall width of the P-type doped region is increased compared to the width of the second region 2 in Example 1, and the increased width is the width by which the first electrode setting area 12 is reduced compared to the first joint part setting area 11. Thus, the area of the PN junction region between the P-type doped region and the N-type substrate is increased, and more electron-hole pairs can be generated, thereby increasing the current. At the same time, the width of the first electrode setting area 12 of the N-type doped region is reduced compared to the width of the first joint part setting area 11 with a limited reduction in width, and the width of the spacer region 3 is reduced compared to the width of the spacer region 3 in Example 1, so that the width of the base region composed of the N-type doped region and the spacer region 3 is reduced, and the lateral path of the minority carriers generated here to the PN junction region is reduced, improving the carrier collection probability. For the above reasons, it is beneficial to improve 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 area 12 in the P-type doped region is reduced compared to the first joint setting area 11, so that the P-type doped region has a first protruding part 111. At the same time, the N-type doped region has a uniform width, and the overall width of the N-type doped region is increased compared to the width of the second region 2 in Example 1. The increased width is the width by which the first electrode setting area 12 is reduced compared to the first joint setting area 11. Similarly, the area of the PN junction region between the N-type doped region and the P-type substrate can be increased, generating more electron-hole pairs, thereby increasing the current. At the same time, the width of the first electrode setting area 12 in the P-type doped region is reduced compared to the width of the first joint setting area 11 with limited width reduction. The width of the spacer region 3 is reduced compared to the width of the spacer region 3 in Example 1, so that the width of the base region composed of the P-type doped region and the spacer region 3 is reduced. The lateral path of the minority carriers generated here to the PN junction region is reduced, improving the carrier collection probability. This is also beneficial to improving the energy conversion efficiency of the solar cell.

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

[0067] In the case of adopting the above technical solution, when the first region 1 has a first protruding part 111, the second electrode setting area 22 and the second joint part setting area 21 of the same second region 2 can have an equal-width structure. 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 protruding part 111 of the first joint part 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 region is optimized to achieve the purpose of improving the energy conversion efficiency.

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

[0069] In the case of adopting the above technical solution, when the first electrode setting region 12 of the first region 1 is narrowed, the second electrode setting region 22 of the second region 2 can also be recessed inward to form the first recessed portion 221, and the pattern of the second region 1 can be optimized as needed by locally narrowing the second electrode setting region 22 of the second region 2.

[0070] Optionally, in this embodiment, the first recessed portion 221 corresponds to the first protruding portion 111 in position and matches 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 spaced apart by the spaced 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 region 12 and the adjacent second electrode setting region 22 can be equal to the distance between the first protruding portion 111 of the first joint portion setting region 11 and the adjacent second electrode setting region 22. Since there will be some errors in the actual measurement of the distance between the first region 1 and the second region 2 of the solar cell or there will be a certain range of fluctuations affected by the surrounding structure, the "equal to" in this application should cover the cases of complete equality and basic equality, and being slightly larger or slightly smaller are regarded as basic equality, and the case of basic equality is applicable and judged according to the actual measurement results. For example, 10% or 20% of the measured value of the distance can be selected as the fluctuation space, and the difference within the range of 10% or 20% can be considered to belong to the case of basic equality.

[0071] For example, the width of the first joint part setting area 11 is set to be wider than that of the first joint part 6, and the first electrode setting area 12 of the first area 1 is narrowed compared with the first joint part setting area 11, so that the first area 1 has a first protruding part 111. If at least a partial width of the second area 2 in this embodiment is increased compared with the corresponding partial position width of the second area 2 in the above Example 1, the width of the second area 2 can be increased as a whole or locally. The locally increased width part usually corresponds to the part where the first electrode setting area 12 in this embodiment is narrowed compared with the first joint part setting area 11. The increased width of the second area 2 is equal to or greater than the width by which the first electrode setting area 12 in this embodiment is narrowed compared with the first joint part setting area 11, and the width of the spaced area 3 between the first electrode setting area 12 of the first area 1 and the second area 2 is unchanged or slightly reduced compared with the spaced area 3 between the first electrode setting area 12 of the first area 1 and the second area 2 in Example 2. By forming a first concave part 221 on the side of the second electrode setting area 22 of the second area 2 close to and corresponding to the first protruding part 111, the width of the spaced area 3 between the first joint part setting area 11 of the first area 1 and the first concave part 221 of the second area 2 is increased compared with the spaced area 3 between the first joint part setting area 11 and the first concave part 221 of the second area 2 in Example 2, thereby ensuring that the width of the spaced area 3 between the first area 1 and the second area 2 is equal. Compared with the situation where the first protruding part 111 and the first concave part 221 do not correspond and match, a sufficient spacing distance is ensured, and the risk of conduction between the first joint part setting area 11 and the second area 2 is reduced.

[0072] In the case of adopting the above technical solution, when the first joint part setting area 11 of the first area 1 has a first protruding part 111, in order to make the distance between the first protruding part 111 and the second electrode setting area 22 of the adjacent second area 2 meet the electrical isolation requirement, the first concave part 221 formed by recessing on the second area 2 can be set to correspond and match with the first protruding part 111, so that the distance at this place 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 of the ways to make the distance between the first electrode setting area 12 and the second electrode setting area 22 equal to the distance between the first protruding part 111 of the first joint part setting area 11 and the adjacent second electrode setting area 22, and it can also be achieved by adjusting the distribution density of the first area 1 and the second area 2 and other means.

[0073] Optionally, in this embodiment, the first recessed portion 221 corresponds to the first protruding portion 111 in position and matches in shape. The first protruding portion 111 is surrounded by the first recessed portion 221, and there is a spacing region 3 between the first protruding portion 111 and the first recessed portion 221. 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 portion setting area 11 and the adjacent second electrode setting area 22.

[0074] For example, the width of the first joint portion setting area 11 is set to be wider than that of the first joint portion 6, and the first electrode setting area 12 of the first region 1 is narrowed compared to the first joint portion setting area 11, so that the first region 1 has the first protruding portion 111. If at least a part of the width of the second region 2 in this embodiment is increased compared to the corresponding local position width of the second region 2 in the above Example 1, the width of the second region 2 can be increased as a whole or locally. The locally increased width part usually corresponds to the part where the first electrode setting area 12 in this embodiment is narrowed compared to the first joint portion setting area 11. The increased width of the second region 2 is greater than the width by which the first electrode setting area 12 in this embodiment is narrowed compared to the first joint portion setting area 11, and the width of the spacing region 3 between the first electrode setting area 12 of the first region 1 and the second region 2 is smaller than the width of the spacing region 3 between the first electrode setting area 12 of the first region 1 and the second region 2 in Example 2. By forming the first recessed portion 221 on the side of 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 spacing region 3 between the first joint portion 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 spacing region 3 between the first joint portion setting area 11 and the first recessed portion 221 of the second region 2 in Example 2, ensuring a sufficient spacing distance, especially increasing the distance between the first electrode setting area 12 and the second electrode setting area 22 that account for a relatively large proportion in the first region 1 and the second region 2, and greatly reducing the risk of conduction between the first joint portion setting area 11 and the second region 2.

[0075] In the case of adopting the above technical solution, when the first joint part setting area 11 in the first area 1 has the first protruding part 111, in order to make the distance between the first protruding part 111 and the second electrode setting area 22 in the adjacent second area 2 meet the electrical isolation requirement, the first recessed part 221 formed by recessing on the second area 2 can be correspondingly and matchingly set with the first protruding part 111, so that the distance at this place is less than the distance between the first electrode setting area 12 and the second electrode setting area 22. The above solution is only one of the ways to make the distance between the first electrode setting area 12 and the second electrode setting area 22 greater than the distance between the first protruding part 111 of the first joint part setting area 11 and the adjacent second electrode setting area 22, and it can also be achieved by adjusting the distribution density of the first area 1 and the second area 2 and other means.

[0076] As Figure 3 and Figure 4 shown, on the basis of any one of the above embodiments, that is, on the basis that the first area 1 has the first protruding part 111, the pattern of the second area 2 is further optimized. In the alternating arrangement direction of the first area 1 and the second area 2, that is, in the first direction, at least one side of the second joint part setting area 21 protrudes towards the adjacent spacer area 3 relative to the second electrode setting area 22, forming the second protruding part 211.

[0077] In the case where the first combination portion setting area 11 has the first protruding portion 111, similarly, since the second combination portion 4 generally has a limited range of adjustable size in order to ensure reliable conductive connection with the interconnection member, the width range of the second region 2 on the solar cell for correspondingly setting the second combination portion 4 is limited. In order to optimize the pattern of the conductive doping region on the cell to obtain better energy conversion efficiency, the present embodiment does not adjust the width range of the second combination portion setting area 21 for setting the second combination portion 4, but only adjusts the width range of the second electrode setting area 22 on the second region 2 where the second combination portion 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 pattern of the second area 2 obtained is that at least one side of the second combination portion setting area 21 protrudes toward the adjacent spacing area 3 relative to the second electrode setting area 22 to form a second protruding portion 211. In this way, the size setting of the second combination portion setting area 21 can be guaranteed, and the coverage area of the overall doped conductive area is reduced by narrowing the doped conductive area at other positions. The pattern of the conductive doped area on the battery is reasonably optimized, and the carrier recombination is reduced to achieve the purpose of improving the energy conversion efficiency of the battery and ensuring the electrical connection reliability of the battery. In addition, even if the factor that the width range of the second combination part setting area 21 is limited by the width of the second combination part 4 is not considered, from the perspective of optimizing current collection, the width of the second combination part setting area 21 can also be set to be wider than the width of the second electrode setting area 22. The width of the second combination part setting area 21 increases, so that the area of the second combination part setting area 21 increases, and the metal electrode collects current. The combination collects the surrounding current on the one hand, and collects the metal electrode output on the other hand. The combination has a dual function compared to the metal electrode. The second combination part setting area 21 and the second electrode setting area 22 are doped conductive areas. The doped conductive areas have a strong lateral carrier transmission ability. Therefore, the width of the second combination part setting area 21 is wider than the width of the second electrode setting area 22, which enhances the carrier transmission and collection around the combination, and narrows the width of the second electrode setting area 22 to adapt to the current collection of the metal electrode part, reduce parasitic absorption, and ultimately achieve optimal collection of carriers on the substrate and improve current transmission efficiency.

[0078] Among them, the second protruding part 211 is formed on one side or both sides of the second joint portion setting area 21, and the second protruding part 211 on each side can be one or more. The pattern design for the second area 2 is also applicable to back contact batteries and non-back contact batteries. Its beneficial effects can be found in the description of the first area in the above embodiments, and will not be repeated here.

[0079] In some embodiments, in a direction perpendicular to the alternating arrangement direction of the first region 1 and the second region 2, that is, Figure 3 and Figure 4In the second direction, the second direction is perpendicular to the first direction. The first protruding part 111 and the adjacent second protruding part 211 are arranged staggeredly, and there is no overlapping part in the projection on the straight line parallel to the second direction. The first protruding part 111 and the adjacent second protruding part 211 are separated by the interval area 3. Since the first protruding part 111 and the second protruding part 211 are arranged staggeredly, correspondingly, the first joint setting area 11 and the second joint setting area 21 are arranged staggeredly, which is convenient for the first joint 6 arranged on the first joint setting area 11 to be connected to the multiple conductive areas arranged along the first direction on the external solder tape or conductive layer extending along the first direction, and at the same time convenient for the second joint 4 arranged on the second joint setting area 21 to be connected to the multiple conductive areas arranged along the first direction on the external solder tape or conductive layer extending along the first direction, so that different solder tapes or conductive areas are staggered in the second direction, avoiding contact to cause short circuit or mutual interference.

[0080] Exemplarily, the first area 1 can be an N-type doped area, the second area 2 can be a P-type doped area, and both the first area 1 and the second area 2 can be strip-shaped areas. The first electrode setting area 12 is used to correspondingly set the first fine grid electrode, the first joint setting area 11 is used to correspondingly set the first joint, the second electrode setting area 22 is used to correspondingly set the second fine grid electrode, and the second joint setting area 21 is used to correspondingly set the second joint. The first area 1 and the second area 2 extend along the second direction. The multiple first joints arranged on the multiple first areas 1 and located in the same first direction are welded by the first solder tape, and the multiple second joints arranged on the multiple second areas 2 and located in the same first direction are welded by the second solder tape. Since the first protruding part 111 and the second protruding part 211 are staggered in the second direction, therefore, the first joint and the second joint are staggered in the second direction, so that the first solder tape and the second solder tape are staggered, avoiding short circuit caused by the contact of the first solder tape and the second solder tape. Or, the multiple first joints arranged on the multiple first areas 1 and located in the same first direction are conductively connected through the multiple first conductive areas arranged along the same first direction on the conductive layer, and the multiple second joints arranged on the multiple second areas 2 and located in the same first direction are conductively connected through the multiple second conductive areas arranged along the same first direction on the conductive layer, so as to facilitate the zoning of the first conductive area and the second conductive area.

[0081] The same applies to the pattern where the first region 1 and the second region 2 are interdigital. For example, the first region 1 includes a plurality of strip-shaped regions corresponding to the first fine grid electrodes and at least one strip-shaped region corresponding to the first main grid electrode, and the strip-shaped regions corresponding to the first fine grid electrodes are perpendicular to the strip-shaped regions corresponding to the first main grid electrode; similarly, the second region 2 includes a plurality of strip-shaped regions corresponding to the second fine grid electrodes and at least one strip-shaped region corresponding to the second main grid electrode, and the strip-shaped regions corresponding to the second fine grid electrodes are perpendicular to the strip-shaped regions corresponding to the second main grid electrode. The first direction refers to the alternating arrangement direction of the strip-shaped regions corresponding to the first fine grid electrode and the second fine grid electrode, that is, the extending direction of the first main grid electrode and the second main grid electrode, and the second direction refers to the extending direction of the strip-shaped regions corresponding to the first fine grid electrode and the second fine grid electrode. On each strip-shaped region corresponding to the first fine grid electrode, there is a first joint setting area 11 where the first joint can be set, and on each strip-shaped region corresponding to the second fine grid electrode, there is a second joint setting area 21 where the second joint can be set. Of course, the first joint setting area 11 can be located on the strip-shaped region corresponding to the first main grid electrode at the same time, and the second joint setting area 21 can be located on the strip-shaped region corresponding to the second main grid electrode at the same time, as long as the first joint and the second joint are staggered in the second direction.

[0082] Optionally, in some embodiments, on the basis that the first protruding part 111 and the second protruding part 211 are staggered in the second direction in the above embodiments, the projection of the first protruding part 111 on a straight line parallel to the alternating arrangement direction of the first region 1 and the second region 2 with respect to the adjacent second protruding part 211 overlaps. That is, the projection of the first protruding part 111 on a straight line parallel to the first direction with respect to the adjacent second protruding part 211 overlaps. With such a setting, the arrangement spacing of the first region 1 and the second region 2 in the first direction can be further reduced. Under the condition of meeting the interval requirements of the interval region 3, the arrangement density of the first region 1 and the second region 2 on the battery can be further increased, improving the energy conversion efficiency and battery utilization rate.

[0083] Such as Figure 4As shown, based on the embodiments in which the second region 2 has the second protruding portion 211 as described above, in this embodiment, the first region 1 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 first electrode setting area 12 is recessed relative to the adjacent spaced area 3 away from the first electrode setting area 12, forming a second recessed portion 121. The number of the second recessed portions 121 on the same first region 1 can be one or more. For the same reason as the second region 2 is provided with the first recessed portion 221, the first electrode setting area 12 of the first region 1 can also be recessed inward to form the second recessed portion 121, and the pattern of the first region 1 can be optimized as needed by locally narrowing the first electrode setting area 12 of the first region 1.

[0084] Optionally, in this embodiment, the second recessed portion 121 corresponds to the second protruding portion 211 in position and matches 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 spaced apart by the spaced area 3. Similarly, in the case where the second joint setting area 21 of the second region 2 has the second protruding portion 211, in order to make the distance between the second protruding portion 211 and the first electrode setting area 12 of the adjacent first region 1 meet the electrical isolation requirement, the second recessed portion 121 formed by recessing on the first region 1 can be correspondingly and matchingly set with the second protruding portion 211, so that the distance at this place is equal to the distance between the second electrode setting area 22 and the first electrode setting area 12. Thus, the width of the spaced area 3 between the first region 1 and the second region 2 is ensured to be equal-width. Compared with the situation where the second protruding portion 211 and the second recessed portion 121 do not correspond and match, a sufficient spaced distance is ensured, and the risk of conduction between the second joint setting area 21 and the first region 1 is reduced.

[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. The dense-grid solar cells narrow the spacing of the metal grid lines, reduce the recombination during the movement of electrons in the direction perpendicular to the grid lines. At the same time, the overall area of the fine grid lines on the cell increases, the series resistance decreases, the fill factor increases, and the cell efficiency is improved. The spacing between the corresponding first fine grid electrode and the second fine grid electrode will decrease, and correspondingly, the corresponding widths of the first region and the second region will decrease. At this time, on the premise of ensuring that the widths of the first joint and the second joint meet the reliability requirements, the first joint setting area and / or the second joint setting area can form a first convex part and / or a second convex part. Correspondingly, the second region can be provided with a first concave part corresponding to the first convex part, and the first region can be provided with a second concave part corresponding to the second convex part. The remaining positions are normally narrowed according to the dense grid spacing. The pattern optimization scheme in this application is more applicable to dense-grid solar cells, which can ensure the reliability of the components while further improving the conversion efficiency of the cells.

[0086] As Figure 4 shown, it should be noted that on the same surface of the solar cell, the first region 1 with the first convex part 111 can exist in any combination with one or more of the second region 2 with the second convex part 211, the second region 2 with the first concave part 221, the first region 1 with the second concave part 121, the second region 2 without the second convex part 211, the second region without the first concave part 221, and the first region 1 without the second concave part 121, which can all be regarded as the pattern optimization of the conductive doping region.

[0087] As Figures 1-6 shown, in some possible implementation manners, in the alternating arrangement direction of the first region 1 and the second region 2, that is, in the first direction, the protruding width of the unilateral first convex part 111 relative to the same side of the first electrode setting area 12 is 40 μm to 80 μm. Specifically, the protruding width of the unilateral first convex part 111 can be 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, etc. The protruding widths of the first convex parts 111 on both sides of the same first joint setting area 11 can be the same or different. When the protruding widths are the same, the first electrode setting area 12 and the first joint setting area 11 are symmetric structures relative to the second direction, and the distances between the first grid line electrode 7 and the first joint 6 set on both sides can be the same, ensuring the uniformity of current collection and reducing the current transmission time.

[0088] Similarly, the protruding width of the unilateral second protruding part 211 relative to the same side of the second electrode setting area 22 is 40 μm to 80 μm. Specifically, the protruding widths of the unilateral second protruding part 211 are 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, etc. The protruding widths of the second protruding parts 211 on both sides of the same second bonding part setting area 21 can be the same or different, and the effect is the same as that of the first protruding part 111, which will not be elaborated here.

[0089] Thus, when the width of the first bonding part setting area 11 remains basically unchanged, if the protruding width is less than this range, it means that the narrowed width of the first electrode setting area 12 is small, and the optimization effect is not obvious. If the protruding width is greater than this range, it means that the narrowed width of the first electrode setting area 12 is large, which affects the current collection in the first area 1 and requires a higher setting accuracy for the subsequent first grid line electrode 7. The reason for selecting the range of the second protruding part 211 is the same as that for selecting the range of the first protruding part 111, which will not be elaborated here.

[0090] As Figure 5 and Figure 6 shown, in some embodiments, the solar cell further includes a first grid line electrode 7 and a first bonding part 6; in the alternating arrangement direction of the first area 1 and the second area 2, that is, in the first direction, the ratio of the width of the first bonding part 6 to the width of the first electrode setting area 12 is 0.35 to 1.4. Specifically, the width ratios can be 0.35, 0.5, 0.64, 0.7, 0.9, 1.0, 1.2, 1.4, etc. The smaller the width ratio, the relatively larger the width of the first electrode setting area 12; the larger the width ratio, the relatively smaller the width of the first electrode setting area 12. When the first bonding part 6 is the first bonding part, the width of the first bonding part is larger, and the corresponding width ratio is larger. When the first bonding part 6 is the 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 bonding part 6 is too small, which is not conducive to reliable connection with the interconnector. Or, the width of the first electrode setting area 12 is too large, and the narrowing of the first electrode setting area 12 is small, and the optimization effect is not obvious. If the width ratio is greater than 1.4, the width of the first bonding part 6 is too large, which is not conducive to electrical isolation and consumes more materials. Or, the width of the first electrode setting area 12 is too small, which is not conducive to carrier collection, and the alignment accuracy requirement for the first grid line electrode 7 is increased. It should be noted that the width of the first bonding part 6 is less than the width of the first bonding part setting area 11.

[0091] Exemplarily, for a back-contact solar cell, taking the substrate as an N-type substrate, the first region 1 as an N-type doped region, and the second region 2 as a P-type doped region as an example, since the width of the first electrode setting region 12 in the N-type doped region is reduced compared to the first joint setting region 11, and at the same time the width of the P-type doped region is increased, the area of the PN junction region between the P-type doped region and the N-type substrate is increased, which can generate more electron-hole pairs, thus increasing the current. At the same time, when the width of the first electrode setting region 12 in the N-type doped region is reduced and the width of the spacer region 3 remains unchanged, the width of the base region composed of the N-type doped region and the spacer region 3 is reduced, and the lateral path of the minority carriers generated here to the PN junction region is reduced, improving the carrier collection probability. Therefore, for the above reasons, the smaller the width of the first electrode setting region 12 in the N-type doped region, the more beneficial it is to improve the energy conversion efficiency of the solar cell. Correspondingly, the larger the ratio of the width of the first joint 6 to the width of the first electrode setting region 12, the more beneficial it is to improve the energy conversion efficiency of the solar cell.

[0092] In some embodiments, the ratio of the width of the first gate line electrode 7 to the width of the first electrode setting region 12 is 0.015 to 0.3, and specifically can be 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 line electrode 7 is too small, which is not conducive to current collection and has a large resistance, or the width reduction of the first electrode setting region 12 is small, which is not conducive to pattern optimization. When the width ratio is greater than 0.3, the width of the first gate line electrode 7 is too large, which is not conducive to electrical isolation and consumes a large amount of material, or the width reduction of the first electrode setting region 12 is too large, which is not conducive to carrier collection.

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

[0094] Such as Figure 5 and Figure 6As shown, in some possible implementation manners, the solar cell further includes a second grid electrode 5 and a second joint portion 4; in the alternating arrangement direction of the first region 1 and the second region 2, that is, in the first direction, the ratio of the width of the second joint portion 4 to the width of the second electrode setting region 22 is 0.2 to 0.7, and specifically may be 0.2, 0.25, 0.3, 0.35, 0.49, 0.55, 0.7, etc.; the smaller the width ratio, it means that the width of the second electrode setting region 22 is relatively larger, and the larger the width ratio, it means that the width of the second electrode setting region 22 is relatively smaller. When the second joint portion 4 is the second joint portion, the width of the second joint portion is larger, and the corresponding width ratio is larger. When the second joint portion 4 is the 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 0.2, the width of the second joint portion 4 is too small, which is not conducive to reliable connection with the interconnector. When the width ratio is greater than 0.7, the width of the second joint portion 4 is too large, which is not conducive to electrical isolation and consumes more materials. It should be noted that the width of the second joint portion 4 is smaller than the width of the second joint portion setting region 21.

[0095] Exemplarily, for a back-contact solar cell, taking the substrate as an N-type substrate, the first region 1 as an N-type doped region, and the second region 2 as a P-type doped region as an example, since the width of the first electrode setting region 12 in the N-type doped region is reduced compared with the first joint portion setting region 11, and at the same time the width of the P-type doped region is increased, the PN junction area between the P-type doped region and the N-type substrate is increased, and more electron-hole pairs can be generated, thereby increasing the current. Therefore, for the above reasons, the larger the width of the second electrode setting region 22 in the P-type doped region, the more conducive it is to improving the energy conversion efficiency of the solar cell. Correspondingly, the smaller the ratio of the width of the second joint portion 4 to the width of the second electrode setting region 22, the more conducive it is to improving the energy conversion efficiency of the solar cell.

[0096] In some embodiments, the ratio of the width of the second grid electrode 5 to the width of the second electrode setting region 22 is 0.012 to 0.12, and specifically may be 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 grid electrode 5 is too small, which is not conducive to current collection and has a large resistance. When the width ratio is greater than 0.12, the width of the second grid electrode 5 is too large, which is not conducive to electrical isolation and consumes more materials.

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

[0098] Three sets of examples and three sets of comparative examples are provided below for parameter comparison:

[0099] Comparative Example 1: By measuring multiple solar cells, a back-contact cell is used, the substrate is an N-type substrate, the first region is an N-type doped region, the second region is a P-type doped region, the first region is a constant-width structure, the second region is a constant-width structure, and the spacer region is a constant-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] Example 1: The solar cell is the same as that in Comparative Example 1. The width of the first joint setting 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 setting area 12 in Example 1 is narrowed compared to the first joint setting area 11, and the width of the first joint setting area 11 remains unchanged, so that the first region forms a first protruding part 111. At this time, the spacer region 3 between the first electrode setting area 12 of the first region 1 and the second region 2 is wider than that in Comparative Example 1, and the width of the spacer region 3 between the first joint setting area 11 and the second region 2 remains the same as the original width of the spacer region 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 of Comparative Example 1 and Example 1

[0103]

[0104] It is found through comparison that after the width of the first electrode setting area 12 of the N-type doped region in Example 2 is reduced, the short-circuit current is increased.

[0105] Comparative Example 2: By measuring multiple solar cells, back-contact cells are also used, which are basically the same as the solution 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 has an equal-width structure. The width of the spacer region in Comparative Example 2 is decreased compared to the original width of the spacer region in Comparative Example 1, and the decreased width is equal to the increased width of the second region in Comparative Example 2 compared to the second region in Comparative Example 1.

[0106] Example 2: It is the same as the cell in Example 1. The difference is 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, and the increased width is equal to the narrowed width of the first electrode setting region 12 compared to the first bonding portion setting region 11. Also, the width of the spacer region 3 between the first electrode setting region 12 of the first region 1 and the second region 2 in Example 2 is equal to the original width of the spacer region in Comparative Example 1. The second region 2 forms a first concave portion 221 corresponding to the first convex portion 111, and the width of the spacer region 3 between the first convex portion 111 of the first bonding portion setting region 11 and the first concave portion 221 is equal to the original width of the spacer 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 of Comparative Example 2 and Example 2

[0109]

[0110] It is found through comparison that when the width of the first electrode setting region 12 of the N-type doping region in Example 2 is narrowed and correspondingly increased onto the P-type doping region, and a first concave portion 221 matching the first convex portion 111 is formed, the conversion efficiency is improved, the fill factor is improved, and the short-circuit current is improved.

[0111] Comparative Example 3: It is basically the same as the solution of 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 second region whose width has already been increased in Comparative Example 2, and the overall width of the spacer region is further decreased on the basis of the spacer region whose width has already been decreased in Comparative Example 2, and the further decreased width of the spacer region is equal to the further increased width of the second region.

[0112] Example 3 is basically the same as the solution in Example 2. The difference is that, on the basis of Example 2, the overall width of the second region in Example 3 is increased compared with the overall width of the second region in Example 2, and the overall width of the interval region in Example 3 is decreased compared with the overall width of the interval region in Example 2, and the decreased width of the interval region is equal to the increased width of the second region. The second region 2 also forms a first concave portion 221 corresponding to the first convex portion 111, and the width of the interval region 3 between the first region 1 and the second region 2 is of equal width.

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

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

[0115]

[0116] It is found by comparison that after the width of the first electrode setting area 12 of the N-type doping region in Example 3 is reduced, it correspondingly increases to the P-type doping region, and 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 also increases to the overall width of the second region 2 and forms a first concave portion 221 matching the first convex portion 111, the conversion efficiency is improved, the fill factor is improved, and the short-circuit current is improved.

[0117] It can be seen that overall, the patterning scheme in the present application is beneficial to improving the energy conversion efficiency of the battery.

[0118] In a second aspect, an embodiment of the present invention further provides a photovoltaic module, which includes a battery string, an interconnector, and a packaging layer; wherein, the battery string is formed by electrically connecting solar cells provided by the first aspect and its various implementation manners; the interconnector is electrically connected to the joint part of the solar cell provided by the first aspect and its various implementation manners, and the joint part is a first joint part and a second joint part, which are used for current collection and assist the solar cells to form a battery string; the packaging layer is used to cover the surface of the battery string.

[0119] For the beneficial effects of the photovoltaic module in the embodiments of the present application, reference can be made to the analysis of the beneficial effects in the first aspect and its various implementation manners, which will not be elaborated here.

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

[0121] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A solar cell, characterized in that, It includes a substrate, at least one side of the substrate includes a first region, a second region and a spacer region, the first region and the second region are arranged alternately, and the first region and the adjacent second region are spaced apart by the spacer region; Wherein, the first region includes a connected first electrode setting area and a first bonding part setting area, the first electrode setting area is used for correspondingly setting a first gate line electrode, and the first bonding part setting area is used for correspondingly setting a first bonding part electrically connected to the first gate line electrode; In the alternating arrangement direction of the first region and the second region, at least one side of the first bonding part setting area protrudes towards the adjacent spacer region relative to the first electrode setting area, forming a first protruding part.

2. The solar cell according to claim 1, wherein In the alternating arrangement direction of the first region and the second region, the opposite sides of the first bonding part setting area respectively protrude towards the adjacent spacer region relative to the first electrode setting area, forming the first protruding part.

3. The solar cell according to claim 1, characterized in that, The second region includes a connected second electrode setting area and a second bonding part setting area, the second electrode setting area is used for correspondingly setting a second gate line electrode, and the second bonding part setting area is used for correspondingly setting a second bonding part 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 bonding part setting area of 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 bonding part 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 connected second electrode setting area and a second bonding part setting area, the second electrode setting area is used for correspondingly setting a second gate line electrode, and the second bonding part setting area is used for correspondingly setting a second bonding part 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 area is recessed away from the adjacent spacer region relative to the second electrode setting area, forming a first recessed part.

5. The solar cell according to claim 4, characterized in that, The first recessed part matches the first protruding part, and the first protruding part and the first recessed part are spaced apart by the spacer 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 bonding part 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 connected second electrode setting area and a second bonding part setting area, the second electrode setting area is used for correspondingly setting a second gate line electrode, and the second bonding part setting area is used for correspondingly setting a second bonding part 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 bonding part setting area protrudes towards the adjacent spacer region relative to the second electrode setting area, forming a second protruding part.

7. The solar cell according to claim 6, characterized in that, In a direction perpendicular to the alternating arrangement direction of the first region and the second region, the first protruding part and the adjacent second protruding part are arranged in a staggered manner and are separated by the spacing region.

8. The solar cell according to claim 7, wherein, The projections of the first protruding part and the adjacent second protruding part 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 spacing region, forming a second recessed part.

10. The solar cell according to claim 9, wherein The second recessed part matches the second protruding part, and the second protruding part and the second recessed part are separated by the spacing 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 protruding width of the first protruding part on the same side as the first electrode setting region is 40 μm to 80 μm; and / or, the protruding width of the second protruding part on the same side as the second electrode setting region is 40 μm to 80 μm.

12. The solar cell according to any one of claims 1-10, characterized in that, The solar cell further includes the first grid line electrode and the first bonding part; In the alternating arrangement direction of the first region and the second region, the ratio of the width of the first bonding part to the width of the first electrode setting region is 0.35 to 1.4; and / or, the ratio of the width of the first grid line electrode to the width of the first electrode setting region is 0.015 to 0.

3.

13. The solar cell according to any one of claims 1-10, characterized in that, The solar cell further includes a second grid line electrode and a second bonding part; In the alternating arrangement direction of the first region and the second region, the ratio of the width of the second bonding part to the width of the second electrode setting region is 0.2 to 0.7; and / or, the ratio of the width of the second grid line electrode to the width of the second electrode setting region is 0.012 to 0.

12.

14. A photovoltaic module, characterized in that, Comprising: a battery string, which is formed by electrically connecting a plurality of solar cells according to any one of claims 1 to 13; an interconnecting member, which is electrically connected to the bonding part of the solar cell; and a packaging layer, which covers the surface of the battery string.

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