Photovoltaic cell and manufacturing method thereof, laminated cell and photovoltaic module

Abstract

The present disclosure relates to the photovoltaic field, and provides a photovoltaic cell and a manufacturing method thereof, a laminated cell, and a photovoltaic module, the photovoltaic cell comprising: a substrate having a first surface side and a second surface side opposite to each other in a first direction; the first surface side comprises a first area and a second area surrounding the first area, and the first area comprises a third area and a fourth area which are alternately arranged in the second direction; the second surface side comprises a fifth area and a sixth area surrounding the fifth area, and the fifth area comprises a seventh area and an eighth area which are alternately arranged in the second direction; the first doped conductive part is positioned in the third region; the first passivation layer is located in the second region; the second passivation layer is located in the sixth region; the tunneling layer is located in the seventh region; and the second doped conductive part is positioned on one side, far away from the substrate, of the tunneling layer. The present disclosure at least facilitates reduction of electric leakage in an edge region in a photovoltaic cell.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, and in particular to a photovoltaic cell and its manufacturing method, a tandem cell, and a photovoltaic module. Background Technology

[0002] With the gradual depletion of fossil fuels, photovoltaic cells are becoming increasingly widely used as a new energy alternative. A photovoltaic cell is a device that converts solar energy into electrical energy. It utilizes the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient use of electrical energy.

[0003] Current photovoltaic cells mainly include BC cells (Back Contact cells), TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated emitter and real cell) cells, and heterojunction cells (Heterojunction with Intrinsic Thin-film, abbreviated as HIT or HJT).

[0004] However, the photoelectric conversion efficiency of current photovoltaic cells still needs to be further improved. Summary of the Invention

[0005] This disclosure provides a photovoltaic cell and its manufacturing method, a tandem cell, and a photovoltaic module, which at least helps to reduce leakage current in the edge region of the photovoltaic cell.

[0006] This disclosure provides a photovoltaic cell, comprising: a substrate having a first surface side and a second surface side opposite to each other along a first direction; the first surface side including a first region and a second region surrounding the first region, the first region including a third region and a fourth region alternately arranged along a second direction; the second surface side including a fifth region and a sixth region surrounding the fifth region, the fifth region including a seventh region and an eighth region alternately arranged along the second direction; a first doped conductive portion located in the third region; a first passivation layer located in the second region; a second passivation layer located in the sixth region; a tunneling layer located in the seventh region; and a second doped conductive portion located on the side of the tunneling layer away from the substrate.

[0007] Optionally, the first region further includes a first connection region, which is adjacent to two adjacent third regions along the second direction, and the first doped conductive portion is also located in the first connection region; and / or, the fifth region further includes a second connection region, which is adjacent to two adjacent eighth regions along the second direction, and the second doped conductive portion is also located in the second connection region.

[0008] Optionally, the first passivation layer includes a first passivation film and a second passivation film, the second passivation film being located on the side of the first passivation film away from the substrate; and / or, the second passivation layer includes a third passivation film and a fourth passivation film, the fourth passivation film being located on the side of the third passivation film away from the substrate.

[0009] Optionally, the passivation layer includes a first passivation layer and a second passivation layer, wherein the second passivation layer is located on the side of the first passivation layer away from the substrate.

[0010] Optionally, the surface morphology of the second region and the surface morphology of the fourth region include the same pyramid structure.

[0011] Optionally, the surface morphology of the third region also includes the pyramid structure.

[0012] Optionally, along the first direction, the spacing between the third region and the second region is 1 μm to 10 μm; and / or, the spacing between the third region and the fourth region is 1 μm to 10 μm.

[0013] Optionally, the surface morphology of the sixth region and the surface morphology of the eighth region are the same polished surface.

[0014] Optionally, along the first direction, the distance between the side of the second doped conductive portion away from the substrate and the sixth region is 1 μm to 5 μm; and / or, the distance between the side of the second doped conductive portion away from the substrate and the eighth region is 1 μm to 5 μm.

[0015] Optionally, the first width of the second region in the third direction is less than or equal to the second width of the second region in the second direction, wherein the third direction intersects with the second direction.

[0016] Optionally, along the second direction, the width of the second region is less than or equal to the width of the fourth region.

[0017] Optionally, along the second direction, the ratio of the width of the third region to the width of the fourth region is 2 to 4.

[0018] This disclosure also provides a method for manufacturing a photovoltaic cell, comprising: providing a substrate having a first surface side and a second surface side opposite to each other along a first direction; the first surface side including a first region and a second region surrounding the first region, the first region including a third region and a fourth region alternately arranged along a second direction; the second surface side including a fifth region and a sixth region surrounding the fifth region, the fifth region including a seventh region and an eighth region alternately arranged along the second direction; forming a first doped conductive portion located in the third region; forming a tunneling layer located in the seventh region; forming a second doped conductive portion located on the side of the tunneling layer away from the substrate; and forming a first passivation layer located in the second region and a second passivation layer located in the sixth region.

[0019] Optionally, the first region further includes a first connection region, which is adjacent to two third regions along the second direction; in the step of forming the first doped conductive portion, the first doped conductive portion is also formed in the first connection region.

[0020] Optionally, the step of forming the first doped conductive portion includes: forming an initial first doped conductive portion located on the first surface side; performing a first laser treatment on the initial first doped conductive portion located in the second region and the fourth region to form a portion to be etched; removing the portion to be etched by a first etching treatment, and further etching a portion of the exposed substrate.

[0021] Optionally, after removing the portion to be etched and before forming the tunneling layer, the method for manufacturing the photovoltaic cell further includes: performing a diffusion treatment to form an oxide layer on the substrate located in the second region and the fourth region, and promoting the diffusion of dopant elements in the initial first doped conductive portion, so that the remaining initial first doped conductive portion located in the third region is transformed into a first doped conductive portion, and forming a protective layer on the side of the first doped conductive portion away from the substrate; and polishing the second surface side using the oxide layer and the protective layer as a mask.

[0022] Optionally, the step of forming the tunneling layer and the second doped conductive portion includes: forming an initial tunneling layer located on the second surface side; forming an initial second doped conductive portion on the side of the initial tunneling layer away from the substrate; performing a second laser processing on the initial second doped conductive portion located in the sixth region and the eighth region; using a second etching process to remove at least the initial second doped conductive portion located in the sixth region and the eighth region and the oxide layer, and further etching a portion of the exposed substrate, the remaining initial second doped conductive portion located in the seventh region being converted into a second doped conductive portion; and using a third etching process to remove at least the protective layer.

[0023] Optionally, after forming the second doped conductive portion, the surface formed by the substrate in the second region and the fourth region and the first doped conductive portion is a first surface, and the surface formed by the substrate in the sixth region and the eighth region and the second doped conductive portion is a second surface; the step of forming the first passivation layer includes: forming a first passivation film on the first surface, and forming a second passivation film on the side of the first passivation film away from the substrate; and / or; the step of forming the second passivation layer includes: forming a third passivation film on the second surface, and forming a fourth passivation film on the side of the third passivation film away from the substrate.

[0024] This disclosure also provides a tandem solar cell, comprising: a base cell, which is a photovoltaic cell as described in any of the preceding claims, or a photovoltaic cell formed by a method for manufacturing a photovoltaic cell as described in any of the preceding claims; and a perovskite cell located on one side of the base cell.

[0025] This disclosure also provides a photovoltaic module, comprising: a battery string, which is formed by connecting a plurality of photovoltaic cells as described in any one of the above claims, or by connecting a plurality of photovoltaic cells formed by a method for manufacturing photovoltaic cells as described in any one of the above claims, or by connecting a plurality of stacked cells as described in the above claims; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film opposite to the battery string.

[0026] The technical solution provided in this disclosure has at least the following advantages: On the one hand, compared to designing the first doped conductive part located in the third region, an additional high-quality first passivation layer is specifically designed in the second region. This separately formed first passivation layer enhances the passivation effect on the second region, reducing carrier recombination in the edge region of the substrate, thereby helping to reduce leakage current in the edge region of the photovoltaic cell. Furthermore, designing the first doped conductive part only in the third region of the first region helps to reduce the parasitic absorption of light by the first doped conductive part, thus synergistically improving the light absorption utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the first surface. On the other hand, compared to designing the tunneling layer and the second doped conductive part located in the seventh region, an additional high-quality second passivation layer is specifically designed in the sixth region. This separately formed second passivation layer enhances the passivation effect on the sixth region, reducing carrier recombination in the edge region of the substrate, thereby helping to reduce leakage current in the edge region of the photovoltaic cell. Furthermore, designing the second doped conductive part only in the seventh region of the fifth region helps to reduce the parasitic absorption of light by the second doped conductive part, thus synergistically improving the light absorption utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the second surface. In addition, the first passivation layer and the second passivation layer can protect the edge areas at different locations in the substrate, preventing the substrate from being bumped or knocked during the production process, thereby improving the yield of photovoltaic cells. Attached Figure Description

[0027] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a first partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 2 This is a second partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 3 This is a first partial overhead view schematic diagram of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 4 This is a second partial overhead view schematic diagram of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 5 for Figures 1 to 4 A schematic diagram of the first type of cross-section along the cross-sectional direction AA1 for any one of them; Figure 6 for Figures 1 to 4 A schematic diagram of the second type of cross-section along the cross-sectional direction AA1 for any one of them; Figure 7 for Figures 1 to 4 A schematic diagram of the third cross-section along the cross-sectional direction AA1 for any one of them; Figure 8 for Figures 1 to 4 A schematic diagram of the fourth cross-section along the cross-sectional direction AA1 for any one of them; Figure 9 for Figures 1 to 4 A schematic diagram of the fifth cross-section along the cross-sectional direction AA1 for any one of them; Figure 10 A process flow diagram of a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 11 This is a partial cross-sectional schematic diagram of a substrate provided in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure; Figure 12 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after the initial first doped conductive portion has been formed. Figure 13 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a first laser treatment. Figure 14 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after removing the doped source layer; Figure 15 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a first etching process; Figure 16 This is a partial cross-sectional schematic diagram of a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure, after a diffusion treatment. Figure 17 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after the initial second doped conductive portion has been formed. Figure 18 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a second etching process. Figure 19 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a third etching process; Figure 20 A partial cross-sectional schematic diagram of a stacked battery provided in yet another embodiment of this disclosure; Figure 21 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in another embodiment of the present disclosure; Figure 22 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in another embodiment of the present disclosure.

[0029] Explanation of reference numerals in the attached figures: 100. Substrate; 101. First surface side; 111. First region; 121. Second region; 131. Third region; 141. Fourth region; 151. First connection region; 102. Second surface side; 112. Fifth region; 122. Sixth region; 132. Seventh region; 142. Eighth region; 152. Second connection region; 103. First doped conductive portion; 113. Initial first doped conductive portion; 123. Region to be etched; 104. First passivation layer; 114. First passivation film; 124. Second passivation film; 105. 105. Second passivation layer; 116. Third passivation film; 127. Fourth passivation film; 108. Tunneling layer; 119. Initial tunneling layer; 100. Second doped conductive part; 110. Initial second doped conductive part; 101. Pyramid structure; 111. First electrode; 122. Second electrode; 103. Doped source layer; 114. Oxide layer; 125. Protective layer; 136. Barrier layer; 147. Bottom cell; 158. Perovskite cell; 49. Photovoltaic cell; 40. Encapsulating film; 41. Cover plate; 42. Solder ribbon. Detailed Implementation

[0030] As can be seen from the background technology, the photoelectric conversion efficiency of photovoltaic cells still needs to be further improved.

[0031] This disclosure provides a photovoltaic cell and its manufacturing method, a tandem cell, and a photovoltaic module. In the photovoltaic cell, on the one hand, compared to designing the first doped conductive part to be located in the third region, an additional high-quality first passivation layer is specially designed in the second region. This improves the passivation effect on the second region by using the separately formed first passivation layer, reducing the recombination of charge carriers in the edge region of the substrate, thereby helping to reduce leakage current in the edge region of the photovoltaic cell. Furthermore, the first doped conductive part is designed only on the third region in the first region, which helps to reduce the parasitic absorption of light by the first doped conductive part. This, in turn, improves the light absorption and utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the first surface side in multiple ways. On the other hand, instead of designing the tunneling layer and the second doped conductive portion in the seventh region, an additional high-quality second passivation layer is specifically designed in the sixth region. This separately formed second passivation layer enhances the passivation effect in the sixth region, reducing carrier recombination in the edge regions of the substrate, thereby helping to reduce leakage current in the edge regions of the photovoltaic cell. Furthermore, the second doped conductive portion is designed only in the seventh region of the fifth region, which helps to reduce the parasitic absorption of light by the second doped conductive portion. This, in turn, synergistically improves the light absorption and utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the second surface. In addition, the first and second passivation layers can protect the edge regions in different parts of the substrate, preventing the substrate from being damaged during the manufacturing process, thus improving the yield of the photovoltaic cell.

[0032] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "multiple" means two or more (including two), unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0035] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of this disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this disclosure. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0036] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0037] In the description of embodiments of this disclosure, the terms "about," "approximately," "roughly," or "about" for a numerical value referring to a specific parameter include the numerical value, and those skilled in the art will understand that the deviation from the numerical value is within acceptable tolerances of the specific parameter. For example, "about" or "about" for a numerical value may include additional numerical values ​​that are in the range of 90.0% to 110.0% of the numerical value, such as in the range of 95.0% to 105.0%, 97.5% to 102.5%, 99.0% to 101.0%, 99.5% to 100.5%, or 99.9% to 100.1%.

[0038] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and / or area of ​​layers, films, panels, regions, etc., are enlarged for better understanding and ease of description. Throughout the specification, the same reference numerals denote the same elements. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on a portion of the edge of the entire surface.

[0039] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. When a component (such as a layer, film, region, or substrate) is described as being on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be an intermediate component between the two components. Conversely, when a component is described as being on the surface of another component, or a component is "directly" on another component, or another component is formed or disposed on the surface of a component, it indicates that there is no intermediate component between the two components. For simplicity and clarity, various components may be drawn at any scale. In the drawings, some components may be omitted for simplicity.

[0040] The “components” mentioned above can refer to layers, films, regions, parts, structures, etc.

[0041] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0042] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the embodiments. However, the technical solutions claimed in the embodiments of this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0043] This disclosure provides a photovoltaic cell according to one embodiment. The photovoltaic cell provided by this disclosure will be described in detail below with reference to the accompanying drawings.

[0044] Reference Figures 1 to 5The photovoltaic cell includes: a substrate 100 having a first surface side 101 and a second surface side 102 opposite to each other along a first direction X; the first surface side 101 includes a first region 111 and a second region 121 surrounding the first region 111, the first region 111 including a third region 131 and a fourth region 141 alternately arranged along a second direction Y; the second surface side 102 includes a fifth region 112 and a sixth region 122 surrounding the fifth region 112, the fifth region 112 including a seventh region 132 and an eighth region 142 alternately arranged along the second direction Y; a first doped conductive portion 103 located in the third region 131; a first passivation layer 104 located in the second region 121; a second passivation layer 105 located in the sixth region 122; a tunneling layer 106 located in the seventh region 132; and a second doped conductive portion 107 located on the side of the tunneling layer 106 away from the substrate 100.

[0045] in, Figure 1 This is a first partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 2 This is a second partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 3 This is a first partial overhead view schematic diagram of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 4 This is a second partial overhead view schematic diagram of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 5 for Figures 1 to 4 A schematic diagram of the first type of cross-section along the cross-sectional direction AA1 for any one of them.

[0046] It should be noted that, in order to clearly illustrate the various areas in the first surface side 101, Figure 1 and Figure 2 Only the first surface side 101 of the substrate 100 is shown, and the film layer located on the first surface side 101 is not shown; to clearly illustrate the various regions in the second surface side 102. Figure 3 and Figure 4 Only the second surface side 102 of the substrate 100 is shown in the diagram; the film layer located on the second surface side 102 is not shown.

[0047] It is worth noting that, on the one hand, the second region 121 in the first surface side 101 surrounds the first region 111. The second region 121 can be regarded as the edge region around the first surface side 101, and the first region 111 can be regarded as the central region of the first surface side 101. Generally, the related film layer formed when the passivation contact structure is provided on the first surface side 101 can be located throughout the entire first surface side 101. However, among the film layers formed throughout the entire first surface side 101, the film layer located in the second region 121 has a lower quality than the film layer located in the first region 111, and is more prone to carrier recombination.

[0048] Based on this, in a photovoltaic cell designed according to an embodiment of the present disclosure, instead of designing the first doped conductive portion 103 located in the third region 131, an additional high-quality first passivation layer 104 is specifically designed on the second region 121. This is to enhance the passivation effect on the second region 121 by means of the separately formed first passivation layer 104, reduce the recombination of charge carriers in the edge region of the substrate 100, and thus help reduce leakage current in the edge region of the photovoltaic cell. Furthermore, the first doped conductive portion 103 is designed only on the third region 131 in the first region 111, which helps to reduce the shading area of ​​the first doped conductive portion 103 on the first surface side 101, thereby reducing the parasitic absorption of light by the first doped conductive portion 103. This, in turn, improves the light absorption utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the first surface side 101 in multiple ways.

[0049] On the other hand, in the second surface side 102, the sixth region 122 surrounds the fifth region 112. The sixth region 122 can be regarded as the edge region around the second surface side 102, and the fifth region 112 can be regarded as the central region of the second surface side 102. Generally, the related film layer formed when the passivation contact structure is provided on the second surface side 102 can be located throughout the second surface side 102. However, among the film layers formed throughout the second surface side 102, the film layer located in the sixth region 122 has a lower quality than the film layer located in the fifth region 112, and is more prone to carrier recombination.

[0050] Based on this, in a photovoltaic cell designed according to an embodiment of the present disclosure, compared to designing the tunneling layer 106 and the second doped conductive portion 107 located in the seventh region 132, an additional high-quality second passivation layer 105 is specifically designed on the sixth region 122. This is to enhance the passivation effect on the sixth region 122 by means of the separately formed second passivation layer 105, reduce the recombination of charge carriers in the edge region of the substrate 100, and thus help reduce leakage current in the edge region of the photovoltaic cell. Furthermore, the second doped conductive portion 107 is designed only on the seventh region 132 in the fifth region 112, which helps to reduce the shading area of ​​the second doped conductive portion 107 on the second surface side 102, thereby reducing the parasitic absorption of light by the second doped conductive portion 107. This, in turn, improves the light absorption utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the second surface side 102 in multiple ways.

[0051] In addition, the first passivation layer 104 and the second passivation layer 105 can protect the edge regions at different locations in the substrate 100, preventing the substrate 100 from being bumped or knocked during the production process, thereby improving the yield of photovoltaic cells.

[0052] It should be noted that the first direction X is the thickness direction of the substrate 100, and the first direction X intersects with the second direction Y. It is worth emphasizing that the intersection of the first direction X and the second direction Y includes: the first direction X and the second direction Y are orthogonal, or the angle formed by the first direction X and the second direction Y is an obtuse angle, or the angle formed by the intersection of the first direction X and the second direction Y is an acute angle.

[0053] In some examples, the angle between the first direction X and the second direction Y can be 10° to 90°, such as 10°, 20°, 45°, 55°, 70°, 82°, or 90°. In some specific examples, the angle between the first direction X and the second direction Y can also be 45° to 90°, such as 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°.

[0054] Furthermore, to clearly illustrate the differences between the film layers disposed in different regions of the first surface side 101, the first surface side 101 is divided into a first region 111 and a second region 121, and the first region 111 is further divided into a third region 131 and a fourth region 141; to clearly illustrate the differences between the film layers disposed in different regions of the second surface side 102, the second surface side 102 is divided into a fifth region 112 and a sixth region 122, and the fifth region 112 is further divided into a seventh region 132 and an eighth region 142.

[0055] It is worth noting that, in order to clearly distinguish between Zone 2 121, Zone 3 131, and Zone 4 141, Figure 1 and Figure 2 Different filling methods are used to draw the second region 121, the third region 131, and the fourth region 141 in the first surface side 101. Furthermore, the relative positional relationship of the second region 121, the third region 131, and the fourth region 141 in the first surface side 101 is the same as the relative positional relationship of the sixth region 122, the seventh region 132, and the eighth region 142 in the second surface side 102. Figure 3 and Figure 4 The sixth zone 122, the seventh zone 132, and the eighth zone 142 in the second surface side 102 are divided only by solid lines.

[0056] The photovoltaic cell provided in one embodiment of this disclosure will be described in detail below with reference to the accompanying drawings.

[0057] In some embodiments, reference Figure 5 One of the first doped conductive portion 103 and the second doped conductive portion 107 is doped with a P-type dopant element, and the other is doped with an N-type dopant element. Furthermore, the substrate 100 may be doped with the same type of dopant element as the first doped conductive portion 103 or the second doped conductive portion 107.

[0058] In some examples, the N-type dopant can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As); the P-type dopant can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or gallium (In).

[0059] In some embodiments, reference Figure 5 The substrate 100 can be made of an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, such as silicon or germanium. The elemental semiconductor material can be monocrystalline, polycrystalline, amorphous, or microcrystalline (a state simultaneously possessing both monocrystalline and amorphous states is called microcrystalline). For example, silicon can be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In other embodiments, refer to... Figure 5 The substrate 100 can also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallium arsenide, perovskite, cadmium telluride, and copper indium selenide. The following description uses silicon as the material for substrate 100 as an example.

[0060] In some cases, the substrate 100 can be an N-type semiconductor substrate doped with N-type dopant, with the first doped conductive portion 103 doped with P-type dopant and the second doped conductive portion 107 doped with N-type dopant. In other cases, the substrate 100 can also be a P-type semiconductor substrate doped with P-type dopant, with the first doped conductive portion 103 doped with P-type dopant and the second doped conductive portion 107 doped with N-type dopant.

[0061] The arrangement of the first doped conductive part 103 in the first region 111 will be described in detail below.

[0062] In some embodiments, in conjunction with reference Figure 2 and Figure 5 The first region 111 may further include a first connection region 151, which is adjacent to two third regions 131 along the second direction Y. The first doped conductive part 103 is also located in the first connection region 151. In other words, the first region 111 not only divides the third region 131 and the fourth region 141, but also divides the first connection region 151. The multiple third regions 131 and the multiple first connection regions 151 together constitute a first "abundant" shaped region. The first doped conductive part 103 is disposed in the first "abundant" shaped region. The first connection region 151 is adjacent to a fourth region 141 on each of its opposite sides along the third direction Z.

[0063] Thus, when designing the fine grid and the main grid subsequently, both the fine grid and the main grid can be directly opposite to the first "丰" - shaped region along the first direction X, providing more transmission paths for carriers. For example, the fine grid can be a conductive structure extending along the third direction Z, and the fine grid is located in the third region 131; the main grid can be a conductive structure extending along the second direction Y, and the main grid is located in multiple third regions 131 and multiple first connection regions 151.

[0064] In some other embodiments, with reference to Figure 1 and Figure 5 , only the third region 131 and the fourth region 141 can be divided in the first region 111, and the extension lengths of the third region 131 and the fourth region 141 along the third direction Z are the same. Thus, when designing the fine grid and the main grid subsequently, the fine grid can be a conductive structure extending along the third direction Z, and the fine grid is located in the third region 131; the main grid can be a conductive structure extending along the second direction Y, and the main grid is not only located in multiple third regions 131 but also located in multiple fourth regions 141.

[0065] The following will elaborate on the settings of the tunneling layer 106 and the second doped conductive part 107 in the fifth region 112.

[0066] In some embodiments, with reference to Figure 4 and Figure 5 , the fifth region 112 can further include a second connection region 152. The second connection region 152 is adjacent to two adjacent eighth regions 142 along the second direction Y, and the second doped conductive part 107 is also located in the second connection region 152. In other words, not only the seventh region 132 and the eighth region 142 are divided in the fifth region 112, but also the second connection region 152 is divided. Multiple seventh regions 132 and multiple second connection regions 152 together form a second "丰" - shaped region. The tunneling layer 106 and the second doped conductive part 107 are arranged in the second "丰" - shaped region, and the two opposite sides of the second connection region 152 along the third direction Z are respectively adjacent to an eighth region 142.

[0067] Thus, when designing the fine grid and the main grid subsequently, both the fine grid and the main grid can be directly opposite to the second "丰" - shaped region along the first direction X, providing more transmission paths for carriers. For example, the fine grid can be a conductive structure extending along the third direction Z, and the fine grid is located in the seventh region 132; the main grid can be a conductive structure extending along the second direction Y, and the main grid is located in multiple seventh regions 132 and multiple second connection regions 152.

[0068] In some other embodiments, with reference to Figure 3 and Figure 5In the fifth region 112, only the seventh region 132 and the eighth region 142 can be divided, and the seventh region 132 and the eighth region 142 have the same extension length in the third direction Z. Thus, when designing the fine gate and the main gate, the fine gate can be a conductive structure extending in the third direction Z, and the fine gate is located in the seventh region 132; the main gate can be a conductive structure extending in the second direction Y, and the main gate is located not only in multiple seventh regions 132 but also in multiple eighth regions 142.

[0069] The following provides a detailed description of the arrangement of the first passivation layer 104 on the first surface side 101.

[0070] In some embodiments, reference Figure 6 , Figure 6 for Figures 1 to 4 In the second cross-sectional view along the cross-sectional direction AA1, the first passivation layer 104 can also be located in the fourth region 141. In other words, the first passivation layer 104 can be provided on the regions of the first surface side 101 where the first doped conductive part 103 is not provided, so as to further enhance the passivation effect on the first surface side 101 by means of the first passivation layer 104. This can not only reduce the recombination of charge carriers in the second region 121, but also reduce the recombination of charge carriers in the fourth region 141, so that more charge carriers can be collected by the first doped conductive part 103.

[0071] In other embodiments, reference is made to Figure 7 or Figure 8 The first passivation layer 104 can also be located on the side of the first doped conductive portion 103 away from the substrate 100. In this way, the first passivation layer 104 can protect the first doped conductive portion 103, avoid the first doped conductive portion 103 from being bumped or knocked during the production process, and ensure that the first doped conductive portion 103 has a good passivation effect on the substrate 100, thereby improving the yield of photovoltaic cells.

[0072] It should be noted that, Figure 7 for Figures 1 to 4 A schematic diagram of the second type of cross-section along the cross-sectional direction AA1 for any one of them; Figure 8 for Figures 1 to 4 A schematic diagram of the fourth cross-section along the cross-sectional direction AA1 for any of them. Furthermore, Figure 5 Taking the first passivation layer 104 located only in the second region 121 as an example, Figure 6 Taking the first passivation layer 104 located in the second region 121 and the fourth region 141 as an example, Figure 7 and Figure 8 In the example, the first passivation layer 104 is located on the side of the second region 121, the fourth region 141 and the first doped conductive portion 103 away from the substrate 100. In actual applications, the first passivation layer can also be located on the side of the second region and the first doped conductive portion away from the substrate.

[0073] In some embodiments, reference Figure 8 The first passivation layer 104 may include a first passivation film 114 and a second passivation film 124, with the second passivation film 124 located on the side of the first passivation film 114 away from the substrate 100. Thus, on the one hand, the first passivation film 114 can improve the lattice fit with the substrate 100 and passivate the substrate 100, thereby reducing the defect state density on the surface of the substrate 100 in contact with the first passivation film 114; on the other hand, the second passivation film 124 can improve the light absorption utilization rate and the protective effect on the film layer located beneath the second passivation film 124.

[0074] In some examples, the material of the first passivation film 114 may include aluminum oxide, and the material of the second passivation film 124 may include silicon nitride. Aluminum oxide generally carries a fixed negative charge, providing good field passivation to the substrate 100; silicon nitride generally carries hydrogen atoms, providing good passivation to the substrate 100. Furthermore, silicon nitride has good anti-reflection properties and high density, thereby improving the light absorption and utilization rate and the protective effect on the film layer located beneath the second passivation film 124. In other examples, the material of the first passivation film 114 or the second passivation film 124 may also include silicon oxide or silicon oxynitride.

[0075] In other embodiments, the first passivation layer may also be a single-film structure or a stacked structure comprising three or more layers.

[0076] The following describes in detail the arrangement of the second passivation layer 105 on the second surface side 102.

[0077] In some embodiments, reference Figure 6 The second passivation layer 105 can also be located in the eighth region 142. In other words, the second passivation layer 105 can be provided in the regions of the second surface side 102 where the second doped conductive part 107 is not provided, so as to further enhance the passivation effect on the second surface side 102 by means of the second passivation layer 105. This can not only reduce the recombination of charge carriers in the sixth region 122, but also reduce the recombination of charge carriers in the eighth region 142, so that more charge carriers can be collected by the second doped conductive part 107.

[0078] In other embodiments, reference is made to Figure 7 or Figure 8 The second passivation layer 105 can also be located on the side of the second doped conductive portion 107 away from the substrate 100. In this way, the second passivation layer 105 can protect the second doped conductive portion 107 from impacts during the production process, thereby ensuring a good passivation effect of the second doped conductive portion 107 on the substrate 100 and improving the yield of photovoltaic cells.

[0079] It should be noted that, Figure 5 Taking the second passivation layer 105 located only in the sixth region 122 as an example, Figure 6 Taking the second passivation layer 105 located in the sixth region 122 and the eighth region 142 as an example, Figure 7 and Figure 8 In the example, the second passivation layer 105 is located in the sixth region 122, the eighth region 142, and the second doped conductive portion 107 on the side away from the substrate 100. In practical applications, the second passivation layer may also be located in the sixth region and the side away from the substrate.

[0080] In some embodiments, reference Figure 8 The second passivation layer 105 includes a third passivation film 115 and a fourth passivation film 125, with the fourth passivation film 125 located on the side of the third passivation film 115 away from the substrate 100. Thus, on the one hand, the third passivation film 115 can improve the lattice fit with the substrate 100 and passivate the substrate 100, thereby reducing the defect state density on the surface of the substrate 100 in contact with the third passivation film 115; on the other hand, the fourth passivation film 125 can improve the light absorption utilization rate and the protective effect on the film layer located beneath the fourth passivation film 125.

[0081] In some examples, the material of the third passivation film 115 may include aluminum oxide, and the material of the fourth passivation film 125 may include silicon nitride. In other examples, the material of the first passivation film 114 or the material of the second passivation film 124 may also include silicon oxide or silicon oxynitride.

[0082] In other embodiments, the second passivation layer may also be a single-film structure or a stacked structure comprising three or more layers.

[0083] It should be noted that within the same photovoltaic cell, such as Figure 8 As shown, both the first passivation layer 104 and the second passivation layer 105 can be double-layer structures. In practical applications, one of the first passivation layer and the second passivation layer can be designed as a single film layer structure and the other as a stacked structure according to specific requirements. In addition, the materials of the first passivation layer and the second passivation layer can be the same or different according to specific requirements.

[0084] In some embodiments, reference Figures 5 to 8The surface morphology of the second region 121 and the fourth region 141 may include the same pyramid structure 108. It should be noted that the same pyramid structure 108 means that the surface morphology of the second region 121 and the fourth region 141 are formed by the same etching process, and the size range of the pyramid structure 108 included in the second region 121 and the fourth region 141 is almost the same. For example, the numerical range of the one-dimensional dimension of the base of the two is almost the same, and the numerical range of the height of the two is also almost the same.

[0085] Thus, on the one hand, the design of the second region 121 and the fourth region 141 based on the pyramid structure 108, which both have a textured surface, is beneficial to improving the light trapping effect of the second region 121 and the fourth region 141, thereby improving the light absorption and utilization rate of the photovoltaic cell. On the other hand, it is beneficial to reduce the difference in surface morphology of the area in the first surface side 101 where the first doped conductive part 103 is not provided. When the first passivation layer 104 is subsequently designed to be located in the second region 121 and the fourth region 141, it is beneficial to reduce the impact of the difference in surface morphology of the second region 121 and the fourth region 141 on the thickness uniformity of the first passivation layer 104, and minimize the difference in passivation effect of different parts of the first passivation layer 104 on the substrate 100, thereby avoiding the situation where the electrical performance of local areas in the photovoltaic cell is poor.

[0086] In some cases, continue to refer to Figures 5 to 8 The surface morphology of the third region 131 can also include a pyramid structure 108. In other words, the size range of the pyramid structures 108 included in the second region 121 and the third region 131 is almost the same. Thus, the entire first surface side 101 can be designed to have a velvety surface, which is beneficial to improving the light trapping effect in each region of the first surface side 101, thereby further improving the photoelectric conversion efficiency of the photovoltaic cell.

[0087] In the various embodiments described above, reference is made to Figures 5 to 7 Along the first direction X, the distance H1 between the third region 131 and the second region 121 can be 1μm to 10μm, for example, 1μm to 5μm or 5μm to 10μm. In other words, the first surface side 101 of the substrate 100 has a step difference at the intersection of the third region 131 and the second region 121, which is beneficial to further improve the light trapping effect by means of the step difference. Moreover, designing the distance H1 between the third region 131 and the second region 121 to be 1μm to 10μm, that is, the step difference of the first surface side 101 is 1μm to 10μm, is beneficial to ensure that the step difference has a good light trapping effect while avoiding structural instability of the photovoltaic cell caused by an excessive step difference, such as avoiding the situation where the second region 121 at the edge is cracked due to stress caused by an excessive step difference.

[0088] It should be noted that when the surface morphology of the third region 131 and the surface morphology of the second region 121 both include pyramid structures 108, along the first direction X, the distance H1 between the third region 131 and the second region 121 refers to the distance between the plane on which the apex of most of the pyramid structures 108 in the third region 131 (e.g., more than 50% of the pyramid structures 108 in the entire third region 131) is located and the plane on which the apex of most of the pyramid structures 108 in the second region 121 (e.g., more than 50% of the pyramid structures 108 in the entire second region 121) is located.

[0089] In some cases, the plane on which the apex of most of the pyramid structures 108 in the second zone 121 is roughly located is higher or more prominent than the plane on which the apex of most of the pyramid structures 108 in the third zone 131 is roughly located compared to the second zone 121.

[0090] In some examples, along the first direction X, the spacing H1 between the third region 131 and the second region 121 can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc.

[0091] In the various embodiments described above, reference is made to Figures 5 to 7 Along the first direction X, the spacing (not shown in the figure) between the third region 131 and the fourth region 141 can also be 1μm to 10μm, for example, 1μm to 5μm or 5μm to 10μm. In other words, the first surface side 101 of the substrate 100 has a step difference at the intersection of the third region 131 and the fourth region 141, which is beneficial to further improve the light trapping effect by means of the step difference. Moreover, designing the spacing between the third region 131 and the fourth region 141 to be 1μm to 10μm, that is, the step difference of the first surface side 101 is 1μm to 10μm, is beneficial to ensure that the step difference has a good light trapping effect while avoiding structural instability of the photovoltaic cell caused by excessive step difference, such as avoiding the situation where the substrate 100 is cracked due to stress caused by excessive step difference.

[0092] It should be noted that when the surface morphology of both the third region 131 and the fourth region 141 includes pyramid structures 108, the distance between the third region 131 and the fourth region 141 along the first direction X refers to the distance between the plane on which the apex of most of the pyramid structures 108 in the third region 131 (e.g., more than 50% of the pyramid structures 108 in the entire third region 131) is approximately located, and the plane on which the apex of most of the pyramid structures 108 in the fourth region 141 (e.g., more than 50% of the pyramid structures 108 in the entire fourth region 141) is approximately located.

[0093] In some cases, the plane on which the apex of most of the pyramid structures 108 in Zone 4 141 is located is roughly higher or more prominent than the plane on which the apex of most of the pyramid structures 108 in Zone 3 131 is located compared to Zone 4 141.

[0094] In some examples, the spacing between the third region 131 and the fourth region 141 along the first direction X can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc.

[0095] It should be noted that, in some cases, when the surface morphology of both the second zone 121 and the fourth zone 141 includes pyramid structures 108, the plane on which the apex of most of the pyramid structures 108 in the second zone 121 is located, and the plane on which the apex of most of the pyramid structures 108 in the fourth zone 141 (e.g., more than 50% of the pyramid structures 108 in the entire fourth zone 141) is located, can be 0 or close to 0.

[0096] In some embodiments, reference Figures 5 to 8 The surface morphology of zone 122 in the sixth region and the surface morphology of zone 142 in the eighth region are the same polished surfaces.

[0097] It should be noted that a polished surface refers to a surface that includes multiple platform structures or base structures. For example, compared to the second region 121, which includes a pyramid structure 108 and has a velvety surface morphology, the sixth and eighth regions 142, which are polished surfaces, have a flatter surface morphology, which is more conducive to improving the thickness uniformity of various film layers formed based on the sixth and eighth regions 142. The platform structures or base structures of the polished surface can be considered as the base portion of a pyramid structure; that is, the polished surface includes multiple square base surfaces.

[0098] In some cases, a polished surface can be the surface formed after the substrate has been texturized to form a pyramid structure, and then polished to remove the apex of the pyramid structure during the polishing process. In other words, the polished surface includes the remaining structure after the apex of the pyramid structure has been removed; that is, the polished surface includes the remaining slightly raised platform structure or the base structure.

[0099] Based on this, the fact that the surface morphology of the sixth zone 122 and the surface morphology of the eighth zone 142 are the same polished surface means that the surface morphology of the sixth zone 122 and the surface morphology of the eighth zone 142 are formed by the same etching process, and the size range of the tower base structure included in the sixth zone 122 and the eighth zone 142 is almost the same. For example, the numerical range of the one-dimensional size of the tower base of the two is almost the same. Thus, when designing the second passivation layer 105 to be located in the sixth region 122 and the eighth region 142, on the one hand, it is beneficial to improve the film quality of the second passivation layer 105 formed on the polished surface, so as to improve the passivation effect of the second passivation layer 105 on the substrate 100; on the other hand, it is beneficial to reduce the difference in surface morphology of the region in the second surface side 102 where the second doped conductive part 107 is not provided, so as to reduce the influence of the difference in surface morphology between the second region 121 and the fourth region 141 on the thickness uniformity of the second passivation layer 105, and minimize the difference in passivation effect of different parts of the second passivation layer 105 on the substrate 100, thereby avoiding the situation where the electrical performance of local areas in the photovoltaic cell is poor.

[0100] In some cases, continue to refer to Figures 5 to 8 The surface morphology of the sixth region 122 and the seventh region 132 can also be the same polished surface. In other words, the size range of the tower base structure included in the sixth region 122 and the seventh region 132 is almost the same. Thus, the entire second surface side 102 can be designed to be a polished surface, and a tunneling layer 106 with better film quality and a second doped conductive portion 107 can be formed on the seventh region 132 to improve the passivation effect of the tunneling layer 106 and the second doped conductive portion 107 on the substrate 100; in addition, if a second passivation layer 105 is also formed on the seventh region 132, the film quality of the second passivation layer 105 in this part can also be improved.

[0101] In some examples, the plane on which most of the base structures in Zone 6 122 (e.g., more than 50% of the base structures in Zone 6 122) are roughly located is used as a reference. The plane on which most of the base structures in Zone 7 132 (e.g., more than 50% of the base structures in Zone 7 132) are roughly located is higher or more prominent than that in Zone 6 122.

[0102] In some cases, continue to refer to Figures 5 to 8 The plane in which most of the base structures in Zone 6 122 are located can be 0 or close to 0 with the plane in which most of the base structures in Zone 8 142 (e.g., more than 50% of the base structures in Zone 8 142) are located.

[0103] In the various embodiments described above, reference is made to Figures 5 to 7Along the first direction X, the distance H2 between the side of the second doped conductive portion 107 away from the substrate 100 and the sixth region 122 is 1μm to 5μm, for example, it can be 1μm to 3μm or 3μm to 5μm. In other words, there is a step difference at the interface between the second doped conductive portion 107 and the substrate 100 located in the sixth region 122, which is beneficial to further improve the light trapping effect by means of the step difference. Moreover, designing the distance H2 between the side of the second doped conductive portion 107 away from the substrate 100 and the sixth region 122 to be 1μm to 5μm is beneficial to avoid the structural instability of the photovoltaic cell caused by the excessive distance between the two, such as avoiding the situation where the sixth region 122 located at the edge is cracked under stress.

[0104] In some examples, along the first direction X, the spacing H2 between the side of the second doped conductive portion 107 away from the substrate 100 and the sixth region 122 can be 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm or 5μm, etc.

[0105] In some embodiments, reference Figures 5 to 7 Along the first direction X, the distance (not shown in the figure) between the side of the second doped conductive portion 107 away from the substrate 100 and the eighth region 142 is 1μm to 5μm, for example, it can be 1μm to 3μm or 3μm to 5μm. In other words, there is a step difference at the interface between the second doped conductive portion 107 and the substrate 100 located in the eighth region 142, which is beneficial to further improve the light trapping effect by means of the step difference. Moreover, designing the distance between the side of the second doped conductive portion 107 away from the substrate 100 and the eighth region 142 to be 1μm to 5μm is beneficial to avoid the structural instability of the photovoltaic cell caused by the excessive distance between the two, such as avoiding the situation where the substrate 100 is cracked under stress.

[0106] In some examples, along the first direction X, the spacing between the side of the second doped conductive portion 107 away from the substrate 100 and the eighth region 142 can be 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm, etc.

[0107] In some embodiments, reference Figure 1 and Figure 2 The first width W1 of the second region 121 in the third direction Z can be less than or equal to the second width W2 of the second region 121 in the second direction Y, where the third direction Z intersects with the second direction Y.

[0108] It should be noted that section 121 is a ring shape. Figures 1 to 2 In the design, the second region 121 is a square ring. In practical applications, the second region can also be a circular ring or a quadrilateral ring, etc. Therefore, the ring size of the second region 121 in different directions can be the same or different.

[0109] Furthermore, in the third direction Z, given the limited size of the first surface side 101, the extension length of the third region 131 is closely related to the first width W1 of the second region 121, and the extension length of the third region 131 determines the extension length of the subsequently formed grid lines. Based on this, designing the first width W1 to be less than or equal to the second width W2 is beneficial to increase the extension length of the third region 131 and the subsequently formed fine grids in the third direction Z by reducing the first width W1, thereby improving the collection efficiency of charge carriers in each region of the substrate 100 by the subsequent fine grids, and thus improving the photoelectric conversion efficiency of the photovoltaic cell. In addition, the subsequent solder ribbon will electrically connect multiple fine grids along the second direction Y. Designing the second width W2 to be larger is beneficial to avoid the fine grids being too close to the edge of the substrate 100 along the second direction Y when the subsequent solder ribbon is electrically connected to the fine grids, so as to avoid excessive pressure from the solder ribbon on the edge of the substrate 100, which could lead to cracking of the photovoltaic cell.

[0110] It should be noted that the electrical connection between the two actually means that both are made of conductive materials and are directly connected or connected through other conductive materials. Therefore, when the photovoltaic cell is generating electricity, there is an electrical connection between the two.

[0111] Furthermore, when the third direction Z intersects with the second direction Y, the third direction Z also intersects with the first direction X. The situations where the third direction Z intersects with the second direction Y and the third direction Z intersects with the first direction X are similar to the situations where the first direction X intersects with the second direction Y, and will not be repeated here.

[0112] In some cases, the first width W1 and / or the second width W2 can be 200μm to 400μm, for example, 200μm to 250μm, 250μm to 300μm, 300μm to 350μm or 350μm to 400μm, etc.

[0113] In some examples, the first width W1 and / or the second width W2 can be 200μm, 210μm, 220μm, 230μm, 240μm, 250μm, 260μm, 270μm, 280μm, 290μm, 300μm, 310μm, 320μm, 330μm, 340μm, 350μm, 360μm, 370μm, 380μm, 390μm, or 400μm, etc.

[0114] In some cases, refer to Figures 1 to 4 The width of the sixth zone 122 in the third direction Z can be the same as the first width W1 of the second zone 121 in the third direction Z, and the width of the sixth zone 122 in the second direction Y can be the same as the second width W2 of the second zone 121 in the second direction Y.

[0115] In some embodiments, reference Figure 1 and Figure 2 Along the second direction Y, the second width W2 of the second zone 121 can be less than or equal to the fourth width W4 of the fourth zone 141.

[0116] It should be noted that in the second direction Y, when the size of the first surface side 101 is limited, the smaller the second width W2, the more third regions 131 and fourth regions 141 can be laid out, and the more fine gates can be laid out subsequently. However, it is also necessary to take into account the pressure of the subsequent solder strip on the second region 121, as well as the mutual influence between adjacent third regions 131. Therefore, the second width W2 is designed to be less than or equal to the fourth width W4, which helps to avoid excessive pressure of the solder strip on the edge of the substrate 100 while reducing the mutual influence between adjacent third regions 131.

[0117] In some cases, the fourth width W4 can be 150μm to 300μm, for example, it can be 150μm to 200μm, 200μm to 250μm or 250μm to 300μm, etc.

[0118] In some examples, the fourth width W4 can be 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, 210μm, 220μm, 230μm, 240μm, 250μm, 260μm, 270μm, 280μm, 290μm, or 300μm, etc.

[0119] In some cases, refer to Figures 1 to 4 The width of the eighth zone 142 in the second direction Y can be the same as the fourth width W4 of the fourth zone 141 in the second direction Y.

[0120] In some embodiments, reference Figure 1 and Figure 2 Along the second direction Y, the ratio of the third width W3 of the third zone 131 to the fourth width W4 of the fourth zone 141 can be 2 to 4, for example, it can be 2 to 2.5, 2.5 to 3, 3 to 3.5 or 3.5 to 4, etc.

[0121] It should be noted that, in the second direction Y, given the limited size of the first region 111, the third width W3 of the third region 131 is closely related to the layout area of ​​the first doped conductive portion 103. Based on this, the ratio of the third width W3 to the fourth width W4 of the fourth region 141 is designed to be 2-4. This helps to avoid the layout area of ​​the first doped conductive portion 103 being too small, ensuring a good passivation effect on the substrate 100, thereby ensuring a high open-circuit voltage for the photovoltaic cell. It also helps to avoid the layout area of ​​the first doped conductive portion 103 being too large, reducing the composite area of ​​the first doped conductive portion 103 and the substrate 100, thereby ensuring a high fill factor for the photovoltaic cell.

[0122] In some cases, the ratio of the third width W3 to the fourth width W4 can be 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, or 4, etc.

[0123] In some cases, the third width W3 can be 500μm to 700μm, for example, it can be 500μm to 550μm, 550μm to 600μm, 600μm to 650μm or 650μm to 700μm, etc.

[0124] In some examples, the third width W3 can be 500μm, 510μm, 520μm, 530μm, 540μm, 550μm, 560μm, 570μm, 580μm, 590μm, 600μm, 610μm, 620μm, 630μm, 640μm, 650μm, 660μm, 670μm, 680μm, 690μm, or 700μm, etc.

[0125] In some cases, refer to Figures 1 to 4 The width of the seventh zone 132 in the second direction Y can be the same as the third width W3 of the third zone 131 in the second direction Y.

[0126] In some embodiments, reference Figure 9 , Figure 9 for Figures 1 to 4 The fifth cross-sectional view of any one of them along the cross-sectional direction AA1 shows that the photovoltaic cell may further include: a first electrode 118 located on the side of the first doped conductive portion 103 away from the substrate 100; and a second electrode 128 located on the side of the second doped conductive portion 107 away from the substrate 100. It should be noted that... Figure 9The first electrode 118 and the second electrode 128 shown in the diagram are both fine grids. In practical applications, when the photovoltaic cell is a grid-connected cell, both the first electrode and the second electrode include not only fine grids but also the grid. Thus, the photovoltaic cell can be a cell with electrodes on both sides, such as a TOPCON cell, a PERC cell, or a heterojunction cell.

[0127] In some cases, continue to refer to Figure 9 The first passivation layer 104 is also located on the side of the first doped conductive portion 103 away from the substrate 100. Based on this, the first electrode 118 also passes through the first passivation layer 104 and is in contact with the first doped conductive portion 103. The second passivation layer 105 is also located on the side of the second doped conductive portion 107 away from the substrate 100. Based on this, the second electrode 128 also passes through the second passivation layer 105 and is in contact with the second doped conductive portion 107.

[0128] In some embodiments, reference Figures 5 to 9 The photovoltaic cell can be a single-sided cell, where the first surface side 101 serves as the light-receiving surface for receiving incident light, and the second surface side 102 serves as the backlighting surface; alternatively, the photovoltaic cell can be a bifacial cell, where both the first surface side 101 and the second surface side 102 can serve as light-receiving surfaces for receiving incident light. It is understood that the backlighting surface described in one embodiment of this disclosure can also receive incident light, but its reception of incident light is weaker than that of the light-receiving surface, and therefore it is defined as a backlighting surface.

[0129] In summary, on the one hand, compared to designing the first doped conductive part 103 located in the third region 131, an additional high-quality first passivation layer 104 is specifically designed in the second region 121. This improves the passivation effect on the second region 121 by utilizing the separately formed first passivation layer 104, reducing the recombination of charge carriers in the edge region of the substrate 100, thereby helping to reduce leakage current in the edge region of the photovoltaic cell. Furthermore, the first doped conductive part 103 is designed only on the third region 131 in the first region 111, which helps to reduce the parasitic absorption of light by the first doped conductive part 103. This, in turn, improves the light absorption utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the first surface side 101 in multiple ways. On the other hand, compared to designing the tunneling layer 106 and the second doped conductive portion 107 located in the seventh region 132, an additional high-quality second passivation layer 105 is specifically designed on the sixth region 122. This separately formed second passivation layer 105 enhances the passivation effect on the sixth region 122, reducing carrier recombination in the edge region of the substrate 100, thereby helping to reduce leakage current in the edge region of the photovoltaic cell. Furthermore, the second doped conductive portion 107 is designed only on the seventh region 132 in the fifth region 112, which helps to reduce the parasitic absorption of light by the second doped conductive portion 107. This, in turn, synergistically improves the light absorption and utilization rate and photoelectric conversion efficiency of the part of the photovoltaic cell near the second surface side 102. In addition, the first passivation layer 104 and the second passivation layer 105 can protect the edge regions of different locations in the substrate 100, preventing the substrate 100 from being damaged during the production process, thereby improving the yield of the photovoltaic cell.

[0130] Another embodiment of this disclosure provides a method for manufacturing a photovoltaic cell, used to form the photovoltaic cell provided in the foregoing embodiment. The manufacturing method of a photovoltaic cell provided in an embodiment of this disclosure will be described in detail below with reference to the accompanying drawings.

[0131] Reference Figures 10 to 19 as well as Figure 8 , Figure 10 This is a process flow diagram of a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. The method for manufacturing a photovoltaic cell includes at least the following steps: S1: Refer to Figure 11 and Figures 1 to 4 A substrate 100 is provided, the substrate 100 having a first surface side 101 and a second surface side 102 opposite to each other along a first direction X; the first surface side 101 includes a first region 111 and a second region 121 surrounding the first region 111, the first region 111 including a third region 131 and a fourth region 141 alternately arranged along a second direction Y; the second surface side 102 includes a fifth region 112 and a sixth region 122 surrounding the fifth region 112, the fifth region 112 including a seventh region 132 and an eighth region 142 alternately arranged along the second direction Y.

[0132] S2: Refer to Figures 12 to 16 A first doped conductive portion 103 is formed in the third region 131.

[0133] S3: Refer to Figures 16 to 19 A tunneling layer 106 is formed in the seventh region 132; a second doped conductive portion 107 is formed on the side of the tunneling layer 106 away from the substrate 100.

[0134] S4: Refer to Figure 19 and Figure 8 A first passivation layer 104 is formed in the second region 121 and a second passivation layer 105 is formed in the sixth region 122.

[0135] In this way, the passivation effect on the second region 121 can be improved by the first passivation layer 104, and the passivation effect on the sixth region 122 can be improved by the second passivation layer 105, thereby helping to reduce leakage current in the edge region of the photovoltaic cell. In addition, the first doped conductive part 103 is designed only on the third region 131 in the first region 111, which helps to reduce the shading area of ​​the first doped conductive part 103 on the first surface side 101. The second doped conductive part 107 is designed only on the seventh region 132 in the fifth region 112, which helps to reduce the shading area of ​​the second doped conductive part 107 on the second surface side 102. This helps to reduce the parasitic absorption of light on both sides of the photovoltaic cell, thereby synergistically improving the light absorption and utilization rate and photoelectric conversion efficiency of the photovoltaic cell from multiple aspects.

[0136] It should be noted that, Figure 11 This is a partial cross-sectional schematic diagram of a substrate provided in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure. Figure 11 The example shown uses a first surface 101 that has not undergone subsequent processes as a textured surface, while the second surface 102 is a relatively flat surface. In practical applications, both the first and second surfaces that have not undergone subsequent processes can be textured. Furthermore, subsequent examples will illustrate this further. Figures 12 to 19 Please provide a detailed explanation.

[0137] The method for forming various film layers on the first surface side 101 and the second surface side 102 will be described in detail below with reference to the accompanying drawings.

[0138] In some embodiments, reference Figure 2 The first region 111 may further include a first connecting region 151, which is adjacent to two third regions 131 along the second direction Y; refer to the reference Figure 2 as well as Figures 12 to 16 In the step of forming the first doped conductive portion 103, the first doped conductive portion 103 is also formed in the first connection region 151.

[0139] In other embodiments, reference is made to Figure 1 In Zone 111, only Zone 3131 and Zone 4141 can be divided; refer to Figure 1 as well as Figures 12 to 16 The first doped conductive portion 103 is located only in the third region 131.

[0140] It should be noted that, in the above two embodiments, in conjunction with the reference... Figures 12 to 16 The steps of forming the first doped conductive portion 103 may include forming an initial first doped conductive portion 113 located on the entire first surface side 101, and then performing patterning processing on the initial first doped conductive portion 113 with different patterns, which will be described in detail later.

[0141] In some embodiments, reference Figure 4 The fifth region 112 may also include a second connecting region 152, which is adjacent to two adjacent eighth regions 142 along the second direction Y; in conjunction with reference Figure 4 as well as Figures 16 to 19 In the step of forming the tunneling layer 106 and the second doped conductive portion 107, the tunneling layer 106 and the second doped conductive portion 107 are also formed in the second connection region 152.

[0142] In other embodiments, reference is made to Figure 3 In zone 5, 112, only zone 7, 132 and zone 8, 142 can be divided; refer to... Figure 3 as well as Figures 16 to 19 The tunneling layer 106 and the second doped conductive part 107 formed are located only in the seventh region 132.

[0143] It should be noted that, in the above two embodiments, in conjunction with the reference... Figures 16 to 19 The steps of forming the tunneling layer 106 and the second doped conductive portion 107 can each include forming an initial tunneling layer 116 and an initial second doped conductive portion 117 located on the entire second surface side 102, and then performing patterning processing on the initial tunneling layer 116 and the initial second doped conductive portion 117 with different patterns, which will be described in detail later.

[0144] In some embodiments, in conjunction with reference Figures 12 to 16 The step of forming the first doped conductive portion 103 may include: referencing Figure 12 An initial first doped conductive portion 113 is formed on the first surface side 101; in conjunction with a reference Figure 12 and Figure 13 The initial first-doped conductive portion 113 located in the second region 121 and the fourth region 141 is subjected to a first laser treatment to form the portion to be etched 123; in conjunction with the reference Figures 13 to 15The first etching process is used to remove the part to be etched 123, and the exposed substrate 100 with a certain thickness is further etched.

[0145] in, Figure 12 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after the initial first doped conductive portion has been formed. Figure 13 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a first laser treatment.

[0146] It is worth noting that in the first laser processing, the doping concentration of the dopant element in different parts of the initial first doped conductive portion 113 was changed, so that the portions of the initial first doped conductive portion 113 located in the second region 121 and the fourth region 141 were transformed into the portion to be etched 123, and the remaining portion of the initial first doped conductive portion 113 located in the third region 131 laid the foundation for the subsequent formation of the first doped conductive portion 103. The doping concentration of the dopant element in the portion to be etched 123 is lower than that in the remaining portion of the initial first doped conductive portion 113. Therefore, compared with the remaining portion of the initial first doped conductive portion 113, the overall lattice order in the portion to be etched 123 is higher, and under the same etching conditions, the portion to be etched 123 is easier to etch.

[0147] Based on this, during the subsequent first etching process, the etching rate of the part to be etched 123 with a lower doping concentration of doped elements is much higher than that of the remaining initial first doped conductive part 113. Thus, without the need for additional masking, the remaining initial first doped conductive part 113 can be used as a mask to remove the part to be etched 123 and further etch a portion of the exposed substrate 100, so that the second region 121 and the fourth region 141 both form a step difference with the third region 131, which helps to simplify the manufacturing process of photovoltaic cells. Furthermore, compared to using a laser ablation process to remove the portions of the initial first doped conductive portion 113 located in the second region 121 and the fourth region 141, i.e., directly using a laser to ablate the portions of the initial first doped conductive portion 113 located in the second region 121 and the fourth region 141 to form a selective emitter structure, the combined effect of the first laser treatment and the first etching treatment helps to reduce laser damage to the first surface side 101. In other words, compared to the laser used in the laser ablation process, the laser used in the first laser treatment causes less laser damage to the first surface side 101, thereby helping to further reduce the surface defect state density of the first surface side 101 and improve the photoelectric conversion efficiency of the final photovoltaic cell.

[0148] In some cases, during the first etching process to further etch a portion of the exposed substrate 100, the surface morphology of the second region 121 and the surface morphology of the fourth region 141 can also be made to include the same pyramid structure 108 simultaneously.

[0149] In some cases, the step of forming the initial first doped conductive portion 113 may include: continuing to refer to Figure 12 The substrate 100 is placed in a diffusion furnace, causing the dopant element to diffuse from the first surface side 101 into the interior of the substrate 100, so that a portion of the substrate 100 is transformed into an initial first doped conductive portion 113. Furthermore, a doped source layer 109 can be formed on the side of the initial first doped conductive portion 113 away from the substrate 100. In other cases, an additional layer of the initial first doped conductive portion can be grown on the first surface side of the substrate.

[0150] It should be noted that the first laser treatment can also increase the porosity of the doped source layer 109 being irradiated, which makes it easier for the first etching process to remove the doped source layer 109 with increased porosity and further remove the part to be etched 123.

[0151] In some examples, boron diffusion can be performed on the substrate 100 by placing the substrate 100 in a diffusion furnace and diffusing at a temperature of 800℃~1000℃ for 2h~5h to form an initial first doped conductive portion 113 and a doped source layer 109. The doped source layer 109 is a borosilicate glass layer, and its thickness in the first direction X can be 10nm~40nm.

[0152] In some examples, the step of performing the first etching process may include: combining a reference Figure 13 and Figure 14 First, the doped source layer 109 located on the first surface side 101 is removed using a first hydrofluoric acid etching solution; then, referring to the reference... Figure 14 and Figure 15 Then, the first alkaline etching solution is used to remove the part to be etched 123, and the exposed substrate 100 located in the second region 121 and the fourth region 141 is texturized.

[0153] in, Figure 14 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after removing the doped source layer; Figure 15 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a first etching process.

[0154] In one example, the mass percentage concentration of hydrofluoric acid in the first hydrofluoric acid etching solution can be 0.5% to 30%, and the etching time of the first hydrofluoric acid etching solution can be 60s to 400s; the mass percentage concentration of sodium hydroxide in the first alkaline etching solution can be 0.5% to 5%, the etching time of the first alkaline etching solution can be 100s to 900s, the temperature of the first alkaline etching solution can be 60℃ to 80℃, and the texturing depth, that is, the distance between the third region 131 and the second region 121, can be 1μm to 10μm.

[0155] In some cases, the laser used in the first laser processing can be a red nano laser.

[0156] In some cases, refer to Figures 15 to 16 After removing the portion to be etched 123 and before forming the tunneling layer 106, the method for manufacturing a photovoltaic cell may further include: combining with a reference Figure 15 and Figure 16 A diffusion process is performed to form an oxide layer 119 on the substrate 100 located in the second region 121 and the fourth region 141, and to promote the diffusion of dopants in the initial first doped conductive portion 113, so that the remaining initial first doped conductive portion 113 located in the third region 131 is transformed into a first doped conductive portion 103, and a protective layer 129 is formed on the side of the first doped conductive portion 103 away from the substrate 100; Continuing to refer to Figure 16 Using the oxide layer 119 and the protective layer 129 as masks, the second surface side 102 is polished. In this way, no additional mask needs to be prepared, and the first doped conductive portion 103 already formed on the first surface side 101 can be protected while polishing the second surface side 102.

[0157] in, Figure 16 This is a partial cross-sectional schematic diagram of a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure, after a diffusion treatment.

[0158] In some examples, during the diffusion process, on the one hand, the substrate 100 exposed by the first etching process, located in the second region 121 and the fourth region 141, is oxidized to form a protective layer 129, for example, the material of the protective layer 129 can be silicon oxide; on the other hand, the doping concentration of the doping element in the initial first doped conductive portion 113 is increased to form the first doped conductive portion 103, and the protective layer 129 is further formed on the side of the first doped conductive portion 103 away from the substrate 100.

[0159] In some examples, the diffusion process may include placing the semi-finished product that has undergone the first etching process in a diffusion furnace and diffusing it at a temperature of 1000°C to 1200°C for 2 to 5 hours to form the first doped conductive part 103 and the protective layer 129.

[0160] In one example, the protective layer 129 can be a borosilicate glass layer, and the thickness of the protective layer 129 in the first direction X can be 70 nm to 150 nm. It should be noted that the protective layer 129 is formed not only on the side of the first doped conductive portion 103 away from the substrate 100, but also on the second surface side 102.

[0161] Based on this, the polishing process of the second surface side 102 may include: firstly using a second hydrofluoric acid etching solution to remove the protective layer 129 located on the second surface side 102; and then using a second alkaline etching solution to etch the second surface side 102 to make the second surface side 102 a polished surface.

[0162] The hydrofluoric acid concentration in the second hydrofluoric acid etching solution can be 10% to 70% by mass, and the etching time of the second hydrofluoric acid etching solution can be 60s; the sodium hydroxide concentration in the second alkaline etching solution can be 0.5% to 5% by mass, the etching time of the second alkaline etching solution can be 100s to 900s, and the temperature of the second alkaline etching solution can be 60℃ to 80℃.

[0163] In some examples, in conjunction with references Figures 17 to 19 The step of forming the tunneling layer 106 and the second doped conductive portion 107 may include the following steps: refer to Figure 17 An initial tunneling layer 116 is formed on the second surface side 102; an initial second doped conductive portion 117 is formed on the side of the initial tunneling layer 116 away from the substrate 100; and the initial second doped conductive portion 117 located in the sixth region 122 and the eighth region 142 is subjected to a second laser treatment.

[0164] Reference Figures 17 to 18 The second etching process removes at least the initial second doped conductive portion 117 and oxide layer 119 located in the sixth region 122 and the eighth region 142, and further etches a portion of the exposed substrate 100. The remaining initial second doped conductive portion 117 located in the seventh region 132 is transformed into the second doped conductive portion 107.

[0165] Reference Figures 18 to 19 The third etching process is used to remove at least 129 protective layers.

[0166] in, Figure 17 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after the initial second doped conductive portion has been formed. Figure 18 This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a second etching process. Figure 19This is a partial cross-sectional schematic diagram of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a third etching process.

[0167] It should be noted that the second laser treatment is different from the first laser treatment. The second laser treatment can be understood as a laser film-opening process, which directly breaks up the initial second doped conductive part 117 that has undergone the second laser treatment, so that the subsequent second etching process can remove the initial second doped conductive part 117.

[0168] In some cases, the laser used in the second laser treatment can be a green laser.

[0169] In some examples, the steps of forming the initial tunneling layer 116 and the initial second doped conductive portion 117 may include: placing the polished semi-finished product in a deposition furnace for deposition treatment and diffusion at a temperature of 400°C to 1000°C for 1 to 4 hours to form the initial tunneling layer 116 and the semiconductor layer sequentially; and then performing phosphorus diffusion by placing the deposited semi-finished product in a diffusion furnace and diffusion at a temperature of 700°C to 1000°C for 1 to 3 hours to transform the semiconductor layer into the phosphorus-doped initial second doped conductive portion 117.

[0170] In one example, a barrier layer 139, such as a phosphosilicate glass layer, is also formed on the side of the initial second-doped conductive portion 117 away from the substrate 100. Subsequently, the barrier layer 139 that has undergone the second laser treatment can be broken up to facilitate the removal of this portion of the barrier layer 139 in the subsequent second etching process; in the step of removing at least the protective layer 129 by the third etching process, the barrier layer 139 that has not undergone the second laser treatment is also removed. Along the first direction X, the thickness of the initial tunneling layer 116 can be 1 nm to 10 nm, the thickness of the semiconductor layer and the initial second-doped conductive portion 117 can be 50 nm to 400 nm, and the thickness of the barrier layer 139 can be 20 nm to 100 nm.

[0171] It is worth noting that in the second etching process, the protective layer 129 located in the third region 131 can prevent the first doped conductive portion 103 from being etched, and the barrier layer 139 located in the seventh region 132, which has not undergone the second laser treatment, can protect the initial tunneling layer 116 and the initial second doped conductive portion 117 located in the seventh region 132 from being etched.

[0172] Furthermore, the initial tunneling layer 116, the initial second doped conductive portion 117, and the barrier layer 139 can also be formed on the surface jointly formed by the oxide layer 119 and the protective layer 129. In the second etching process, the initial tunneling layer 116, the initial second doped conductive portion 117, and the oxide layer 119 located on the first surface side 101 are all removed.

[0173] Based on this, before performing the second etching process, a hydrofluoric acid solution can be used to remove the barrier layer 139 located on the first surface side 101, wherein the mass percentage concentration of hydrofluoric acid in the hydrofluoric acid solution can be 30%~50%.

[0174] In one example, the second etching process may include: using a third alkaline etching solution to remove the initial second doped conductive portion 117, the initial tunneling layer 116, and the oxide layer 119 located on the first surface side 101, and removing the barrier layer 139, the initial second doped conductive portion 117, and the initial tunneling layer 116 that have undergone the second laser treatment, and further etching the exposed substrate 100 located in the sixth region 122 and the eighth region 142, so that the surface morphology of the sixth region 122 and the eighth region 142 is a polished surface.

[0175] The mass percentage concentration of sodium hydroxide in the third alkaline etching solution can be 0.5% to 5%, the etching time of the third alkaline etching solution can be 100s to 1000s, the temperature of the third alkaline etching solution can be 60℃ to 80℃, and the distance between the side of the second doped conductive part 107 away from the substrate 100 and the sixth region 122 is 1μm to 5μm.

[0176] In one example, the third etching process may include removing the protective layer 129 located in the third region 131 and the barrier layer 139 located in the seventh region 132 using a third hydrofluoric acid etching solution. The mass percentage concentration of hydrofluoric acid in the third hydrofluoric acid etching solution may be 30% to 70%, and the etching time of the third hydrofluoric acid etching solution may be 100 s to 1000 s.

[0177] In some examples, in conjunction with references Figure 19 and Figure 8 After the second doped conductive portion 107 is formed, the surface formed by the substrate 100 located in the second region 121 and the fourth region 141 and the first doped conductive portion 103 is the first surface, and the surface formed by the substrate 100 located in the sixth region 122 and the eighth region 142 and the second doped conductive portion 107 is the second surface.

[0178] In one example, continue to refer to the reference. Figure 19 and Figure 8 The step of forming the first passivation layer 104 may include: forming a first passivation film 114 on a first surface, and forming a second passivation film 124 on the side of the first passivation film 114 away from the substrate.

[0179] In one example, continue to refer to the reference. Figure 19 and Figure 8 The step of forming the second passivation layer 105 may include: forming a third passivation film 115 on the second surface, and forming a fourth passivation film 125 on the side of the third passivation film 115 away from the substrate.

[0180] It should be noted that the first passivation layer 104 and the second passivation layer 105 can be formed simultaneously or separately. When the first passivation layer 104 and the second passivation layer 105 are formed simultaneously, the first passivation film 114 and the third passivation film 115 can be formed simultaneously, and the second passivation film 124 and the fourth passivation film 125 can be formed simultaneously.

[0181] Another embodiment of this disclosure provides a tandem battery, which includes the photovoltaic cell provided in the foregoing embodiments, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the foregoing embodiments. The tandem battery provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to those in the foregoing embodiments will not be repeated here.

[0182] refer to Figure 20 , Figure 20 This is a partial cross-sectional schematic diagram of a tandem solar cell provided in another embodiment of the present disclosure. The tandem solar cell includes: a bottom cell 149, which is a photovoltaic cell provided in the aforementioned embodiment, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the aforementioned embodiment; and a perovskite cell 159, which is located on one side of the bottom cell 149.

[0183] In some embodiments, the perovskite solar cell 159 may include: a first transport layer, a perovskite substrate, a second transport layer, a transparent conductive layer, and an antireflection layer stacked together. The first transport layer is directly opposite the bottom solar cell 149.

[0184] In some examples, the first transport layer can be either an electron transport layer or a hole transport layer, and the second transport layer can be either an electron transport layer or a hole transport layer.

[0185] In some embodiments, the bandgap width of the perovskite cell 159 is wider than that of the bottom cell 149. Therefore, stacking the perovskite cell 159 on top of the bottom cell 149 can give the stacked cell a wider spectral response range, thereby maximizing the utilization of solar energy and improving the efficiency of the photovoltaic cell.

[0186] In some embodiments, the stacked cell may further include an intermediate connecting layer (not shown in the figure), which connects the bottom cell 149 and the perovskite cell 159.

[0187] In some cases, the intermediate connecting layer is typically a tunnel junction or a very thin metal or transparent electrode composite layer. Optionally, the intermediate connecting layer can be a transparent conductive oxide, which has good optoelectronic properties, high photon transmittance, and high conductivity, thereby enabling the perovskite solar cell 159 and the bottom cell 149 to maintain good ohmic contact.

[0188] In other cases, the back grid, back main grid, front grid, and front main grid of the photovoltaic cell serving as the bottom cell 149 can also serve as an intermediate connection layer for electrical connection with the perovskite cell 159.

[0189] Another embodiment of this disclosure provides a photovoltaic module, which includes multiple photovoltaic cells as provided in the foregoing embodiments, or photovoltaic cells formed by the manufacturing method of multiple photovoltaic cells as provided in the foregoing embodiments, or multiple stacked cells as provided in the foregoing embodiments connected together. The photovoltaic module is used to convert received light energy into electrical energy. It should be noted that the parts that are the same as or corresponding to the foregoing embodiments can be referred to the corresponding descriptions of the foregoing embodiments, and will not be repeated below.

[0190] Reference Figure 21 , Figure 22 as well as Figures 1 to 9 The photovoltaic module may include: a battery string, which is formed by connecting multiple photovoltaic cells 40 provided in the foregoing embodiments, or by connecting multiple photovoltaic cells 40 formed by the manufacturing method of photovoltaic cells provided in the foregoing embodiments, or by connecting multiple stacked cells provided in the foregoing embodiments; an encapsulating film 41 for covering the surface of the battery string; and a cover plate 42 for covering the surface of the encapsulating film 41 facing away from the battery string.

[0191] in, Figure 21 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in another embodiment of the present disclosure; Figure 22 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in another embodiment of the present disclosure.

[0192] In some embodiments, the photovoltaic cells 40 are electrically connected in the form of a single cell or multiple segments to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel. The photovoltaic cells 40 can be a single cell or a sliced ​​cell, where a sliced ​​cell refers to a cell formed by cutting a complete single cell.

[0193] In some embodiments, in conjunction with reference Figure 21 and Figure 22 Multiple photovoltaic cells 40 can be electrically connected to each other via solder strips 43. Figure 21 and Figure 22This illustration only shows one positional relationship between photovoltaic cells 40, where the grid lines of the photovoltaic cells 40 with the same polarity are arranged in the same direction, or in other words, the grid lines of each photovoltaic cell 40 with the positive polarity are arranged facing the same side, so that the solder ribbon 43 connects different sides of two adjacent photovoltaic cells 40 respectively. In other embodiments, the photovoltaic cells can also be arranged with electrodes of different polarities facing the same side, that is, the electrodes of multiple adjacent photovoltaic cells are arranged in the order of first polarity, second polarity, and first polarity respectively, then the solder ribbon connects two adjacent photovoltaic cells on the same side.

[0194] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the photovoltaic cell 40, and the second encapsulating layer covers the other of the front or back sides of the photovoltaic cell 40. Specifically, at least one of the first or second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first or second encapsulating layer can also be an EP film, an EPE film, or a PVP film. Here, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film + POE film + EVA film; and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0195] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0196] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0197] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic cell, characterized in that, include: The substrate has a first surface side and a second surface side opposite to each other along a first direction; the first surface side includes a first region and a second region surrounding the first region, the first region including a third region and a fourth region alternately arranged along a second direction; the second surface side includes a fifth region and a sixth region surrounding the fifth region, the fifth region including a seventh region and an eighth region alternately arranged along the second direction; The first doped conductive portion is located in the third region; The first passivation layer is located in the second region; The second passivation layer is located in the sixth region; The tunneling layer is located in the seventh region; The second doped conductive portion is located on the side of the tunneling layer away from the substrate.

2. The photovoltaic cell according to claim 1, characterized in that, The first region further includes a first connection region, which is adjacent to two third regions along the second direction, and the first doped conductive portion is also located in the first connection region; And / or, the fifth region further includes a second connection region, the second connection region being adjacent to two adjacent eighth regions along the second direction, and the second doped conductive portion is also located in the second connection region.

3. The photovoltaic cell according to claim 1, characterized in that, The first passivation layer is also located in the fourth region and / or on the side of the first doped conductive portion away from the substrate; and / or, the second passivation layer is also located in the eighth region and / or on the side of the second doped conductive portion away from the substrate.

4. The photovoltaic cell according to any one of claims 1 to 3, characterized in that, The first passivation layer includes a first passivation film and a second passivation film, the second passivation film being located on the side of the first passivation film away from the substrate; and / or, the second passivation layer includes a third passivation film and a fourth passivation film, the fourth passivation film being located on the side of the third passivation film away from the substrate.

5. The photovoltaic cell according to claim 1, characterized in that, The surface morphology of the second region and the surface morphology of the fourth region include the same pyramid structure.

6. The photovoltaic cell according to claim 5, characterized in that, The surface morphology of the third region also includes the pyramid structure.

7. The photovoltaic cell according to any one of claims 1, 5, or 6, characterized in that, Along the first direction, the distance between the third region and the second region is 1 μm to 10 μm; and / or, the distance between the third region and the fourth region is 1 μm to 10 μm.

8. The photovoltaic cell according to claim 1, characterized in that, The surface morphology of the sixth region and the surface morphology of the eighth region are the same polished surface.

9. The photovoltaic cell according to any one of claims 1 or 8, characterized in that, Along the first direction, the distance between the side of the second doped conductive portion away from the substrate and the sixth region is 1 μm to 5 μm; and / or, the distance between the side of the second doped conductive portion away from the substrate and the eighth region is 1 μm to 5 μm.

10. The photovoltaic cell according to claim 1, characterized in that, The first width of the second region in the third direction is less than or equal to the second width of the second region in the second direction, and the third direction intersects with the second direction.

11. The photovoltaic cell according to claim 1, characterized in that, Along the second direction, the second width of the second region is less than or equal to the fourth width of the fourth region.

12. The photovoltaic cell according to claim 1, characterized in that, Along the second direction, the ratio of the third width of the third region to the fourth width of the fourth region is 2 to 4.

13. A method for manufacturing a photovoltaic cell, characterized in that, include: A substrate is provided having a first surface side and a second surface side opposite to each other along a first direction; the first surface side includes a first region and a second region surrounding the first region, the first region including a third region and a fourth region alternately arranged along a second direction; the second surface side includes a fifth region and a sixth region surrounding the fifth region, the fifth region including a seventh region and an eighth region alternately arranged along the second direction; A first doped conductive portion is formed in the third region; A tunneling layer is formed in the seventh region; A second doped conductive portion is formed on the side of the tunneling layer away from the substrate; A first passivation layer is formed in the second region and a second passivation layer is formed in the sixth region.

14. The method for manufacturing a photovoltaic cell according to claim 13, characterized in that, The first region further includes a first connection region, which is adjacent to two third regions along the second direction; in the step of forming the first doped conductive portion, the first doped conductive portion is also formed in the first connection region.

15. The method for manufacturing a photovoltaic cell according to claim 13 or 14, characterized in that, The step of forming the first doped conductive portion includes: An initial first doped conductive portion is formed on the side of the first surface; The initial first doped conductive portion located in the second region and the fourth region is subjected to a first laser treatment to form the portion to be etched; The first etching process is used to remove the portion to be etched, and then a portion of the exposed substrate is further etched.

16. The method for manufacturing a photovoltaic cell according to claim 15, characterized in that, After removing the part to be etched and before forming the tunneling layer, the method for manufacturing the photovoltaic cell further includes: performing a diffusion treatment to form an oxide layer on the substrate located in the second region and the fourth region, and promoting the diffusion of dopant elements in the initial first doped conductive portion, so that the remaining initial first doped conductive portion located in the third region is transformed into a first doped conductive portion, and forming a protective layer on the side of the first doped conductive portion away from the substrate. Using the oxide layer and the protective layer as masks, the second surface side is polished.

17. The method for manufacturing a photovoltaic cell according to claim 16, characterized in that, The steps of forming the tunneling layer and the second doped conductive portion include: An initial tunneling layer is formed on the second surface side; An initial second doped conductive portion is formed on the side of the initial tunneling layer away from the substrate; The initial second doped conductive portion located in the sixth region and the eighth region is subjected to a second laser treatment; The second etching process removes at least the initial second doped conductive portion and the oxide layer located in the sixth region and the eighth region, and further etches a portion of the exposed substrate, and the remaining initial second doped conductive portion located in the seventh region is transformed into a second doped conductive portion; The protective layer is removed at least by a third etching process.

18. The method for manufacturing a photovoltaic cell according to claim 17, characterized in that, After the second doped conductive portion is formed, the surface formed by the substrate in the second region and the fourth region and the first doped conductive portion is the first surface, and the surface formed by the substrate in the sixth region and the eighth region and the second doped conductive portion is the second surface; The step of forming the first passivation layer includes: forming a first passivation film on the first surface, forming a second passivation film on the side of the first passivation film away from the substrate; and / or; The step of forming the second passivation layer includes: forming a third passivation film on the second surface, and forming a fourth passivation film on the side of the third passivation film away from the substrate.

19. A stacked battery, characterized in that, include: The bottom cell is a photovoltaic cell as described in any one of claims 1 to 12, or a photovoltaic cell formed by the manufacturing method of a photovoltaic cell as described in any one of claims 13 to 18; A perovskite solar cell, wherein the perovskite solar cell is located on one side of the bottom solar cell.

20. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple photovoltaic cells as described in any one of claims 1 to 12, or by connecting multiple photovoltaic cells formed by the manufacturing method of photovoltaic cells as described in any one of claims 13 to 18, or by connecting multiple stacked cells as described in claim 19; An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

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