Photovoltaic cell and method of manufacturing the same, photovoltaic module

Abstract

The present disclosure relates to the field of photovoltaics, and provides a photovoltaic cell, a manufacturing method thereof, and a photovoltaic module. The manufacturing method of the photovoltaic cell comprises: providing a first substrate, the first substrate having two first surfaces opposite along a first direction, the first direction being a thickness direction of the first substrate; wherein at least one of the first surfaces comprises first pyramid structures, and the top of at least a part of the first pyramid structures has a defect part; performing a first texturing treatment on the first substrate to remove the defect part and form second pyramid structures and first protruding structures on the basis of the first pyramid structures to form a second substrate; wherein the first protruding structures are located on the side and / or side edge of the second pyramid structures, and along the first direction, the height of the first protruding structures is less than the height of the second pyramid structures. The present disclosure is at least beneficial to form a second substrate with a special surface morphology while removing the defect part.

Description

Technical Field

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

[0002] With the rapid development of solar photovoltaic technology, photovoltaic cells are becoming increasingly widely used as a sustainable and clean energy source. A photovoltaic cell is a device that uses the photovoltaic principle to generate charge carriers to convert sunlight into electrical energy. During the manufacturing process of photovoltaic cells, a texturing process is typically required to treat at least part of the substrate surface to form a pyramidal textured structure suitable for light trapping.

[0003] However, the pyramidal textured surfaces formed by different texturing processes vary considerably, and further research is needed to determine which pyramidal textured surface morphology is more conducive to light trapping. Furthermore, the manufacturing process of photovoltaic cells may involve multiple texturing processes, or other production processes besides texturing, which can easily affect the morphology of the initially formed pyramidal textured surface. Summary of the Invention

[0004] This disclosure provides a photovoltaic cell and its manufacturing method, as well as a photovoltaic module, which at least facilitates the formation of a second substrate with a special surface morphology while removing defective parts.

[0005] This disclosure provides a method for manufacturing a photovoltaic cell, comprising: providing a first substrate having two first surfaces opposite each other along a first direction, the first direction being the thickness direction of the first substrate; wherein at least one of the first surfaces includes a first pyramid structure, and at least a portion of the first pyramid structure has a defect at its top; performing a first texturing process on the first substrate to remove the defect, and forming a second pyramid structure and a first protrusion structure on the basis of the first pyramid structure to form a second substrate; wherein the first protrusion structure is located on the side and / or side edge of the second pyramid structure, and along the first direction, the height of the first protrusion structure is less than the height of the second pyramid structure.

[0006] Optionally, the first base further has a first side surface connecting the two first surfaces, the first side surface including a third pyramid structure, and at least a portion of the top of the third pyramid structure having the defect portion; in the step of performing the first texturing process, the defect portion is removed, and a fourth pyramid structure and a second protrusion structure are formed on the basis of the third pyramid structure; wherein the second protrusion structure is located on the side surface and / or side edge of the fourth pyramid structure, and along the direction away from the first side surface, the height of the second protrusion structure is less than the tower height of the fourth pyramid structure.

[0007] Optionally, the base size of the third pyramid structure is smaller than that of the first pyramid structure; and / or, the base size of the fourth pyramid structure is smaller than that of the second pyramid structure.

[0008] Optionally, the base size of the third pyramid structure is 1μm to 3μm, and the height of the third pyramid structure in the direction perpendicular to the first side is 0.2μm to 1.5μm; and / or, along the first direction, the base size of the fourth pyramid structure is 1μm to 4.5μm, and the height of the fourth pyramid structure in the direction perpendicular to the first side is 0.5μm to 2.5μm.

[0009] Optionally, the step of providing the first substrate includes: providing an initial substrate; performing a second texturing process on the initial substrate to form a substrate having two substrate surfaces opposite each other along the first direction, at least one of the substrate surfaces including a fifth pyramid structure; stacking a plurality of the substrates or performing a position transfer on the first substrate after stacking, such that the substrates are transformed into the first substrate.

[0010] Optionally, the step of providing the first substrate includes: providing an initial substrate; performing a second texturing process on the initial substrate to form a substrate having two substrate surfaces opposite each other along the first direction and a substrate sidewall connecting the two substrate surfaces, the substrate sidewall including a sixth pyramid structure; and stacking a plurality of the substrates such that the substrates are transformed into the first substrate.

[0011] Optionally, the first texturing process is performed at a first production site, and the second texturing process is performed at a second production site; wherein the first production site and the second production site are located in different factories, or the first production site and the second production site are located in different areas of the same factory.

[0012] Optionally, the first texturing process includes at least: performing a first wet cleaning process and a first wet texturing process on the first substrate.

[0013] Optionally, after performing the first wet texturing process, the step of performing the first texturing treatment further includes: performing a water washing process; and / or, performing an oxidation cleaning process; and / or, performing a wet acid washing process.

[0014] Optionally, the cleaning solution used in the oxidation cleaning process is a mixed solution comprising hydrochloric acid and ozone, wherein the hydrochloric acid has a weight percentage of 0.01wt% to 3wt%, and the concentration of ozone dissolved in the mixed solution is 10ppm to 60ppm; or, the cleaning solution used in the oxidation cleaning process is a mixed solution comprising hydrofluoric acid and hydrogen peroxide, wherein the hydrofluoric acid has a weight percentage of 0.5wt% to 10wt%, and the hydrogen peroxide has a weight percentage of 0.5wt% to 10wt%.

[0015] Optionally, the cleaning solution used in the wet pickling process is a mixed solution comprising hydrofluoric acid and pickling additives, wherein the weight percentage of hydrofluoric acid is 0.5wt% to 8wt% and the weight percentage of pickling additives is 0.5wt% to 5wt%.

[0016] Optionally, the step of providing the first substrate includes performing a second texturing process; wherein the step of performing the second texturing process includes performing a second wet cleaning process and a second wet texturing process.

[0017] Optionally, at least one of the first wet cleaning process and the second wet cleaning process uses a cleaning solution comprising a mixed solution of alkali and hydrogen peroxide, wherein the alkali is sodium hydroxide or potassium hydroxide; wherein the weight percentage of the alkali is 0.1wt% to 10wt%, and the weight percentage of the hydrogen peroxide is 0.5wt% to 10wt%.

[0018] Optionally, the cleaning solution used in at least one of the first wet texturing process and the second wet texturing process is a mixed solution comprising an alkali and a texturing additive, wherein the alkali is sodium hydroxide or potassium hydroxide; wherein the weight percentage of the alkali is 0.1wt% to 10wt%, and the weight percentage of the texturing additive is 0.1wt% to 10wt%.

[0019] Optionally, the process temperature of at least one of the first wet texturing process and the second wet texturing process is 55℃~85℃; and / or, the process duration of at least one of the first wet texturing process and the second wet texturing process is 100s~800s.

[0020] Optionally, the base size of the second pyramid structure is greater than or equal to the base size of the first pyramid structure; and / or, the height of the second pyramid structure is greater than or equal to the height of the first pyramid structure.

[0021] Optionally, the base size of the first pyramid structure is 1μm to 4.5μm, and the base size of the second pyramid structure is 1μm to 5μm; and / or, along the first direction, the height of the first pyramid structure is 0.5μm to 2μm, and the height of the second pyramid structure is 0.5μm to 2.5μm.

[0022] Optionally, the initial substrate may be subjected to getter and impurity removal treatments before the second texturing process; or, the substrate or the first substrate may be subjected to getter and impurity removal treatments after the second texturing process and before the first texturing process.

[0023] This disclosure also provides a photovoltaic cell, which is a photovoltaic cell as described in any of the preceding claims.

[0024] This disclosure also provides a photovoltaic module, comprising: a battery string, which is formed by connecting a plurality of photovoltaic cells manufactured by any of the above methods, or by connecting a plurality of photovoltaic cells as described above; 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.

[0025] The technical solution provided in this disclosure has at least the following advantages: The design involves a first texturing process on a first substrate with defects to remove these defects and form a second surface comprising a second pyramid structure and a first protrusion structure. The first protrusion structure located on the sides and / or edges of the second pyramid structure, along with the second pyramid structure itself, can be considered as forming a clustered pyramid assembly. This facilitates the formation of more light-trapping areas, enhancing the light-trapping effect of the second substrate. Furthermore, the clustered pyramid assembly makes the surface of the second substrate rougher, improving ohmic contact between the subsequent electrodes and the second substrate. This enhances the photoelectric conversion efficiency of the photovoltaic cell in terms of both light utilization and conductivity. Moreover, compared to a conventional texturized surface, the clustered pyramid assembly formed by the second pyramid structure and the first protrusion structure has a smaller height difference, or lower unevenness per unit area. This is more conducive to the formation of subsequent passivation contact structures and electrode printing. The clustered pyramid assembly also more effectively utilizes the gaps between adjacent second pyramid structures, increasing the density and compactness of the texturized surface, reducing the reflectivity of the second substrate, and further promoting passivation and current enhancement in the photovoltaic cell, thereby improving the photoelectric performance of the photovoltaic cell. Attached Figure Description

[0026] 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.

[0027] Figure 1 A process flow diagram of a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 2 A scanning electron microscope image of the first surface of the first substrate in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 3 A scanning electron microscope image of a first side surface of a first substrate in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 4 This is a schematic cross-sectional view of a first substrate in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Figure 5 A scanning electron microscope image of a second substrate in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 6 This is a schematic cross-sectional view of a second substrate in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Figure 7 This is a schematic cross-sectional view of an initial substrate in a photovoltaic cell manufacturing method according to an embodiment of the present disclosure. Figure 8 This is a schematic cross-sectional view of a substrate in a photovoltaic cell manufacturing method according to an embodiment of the present disclosure. Figure 9 This is a schematic cross-sectional view of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after multiple substrates are stacked. Figure 10 This is a schematic cross-sectional view of a photovoltaic cell in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure. Figure 11 This is a schematic diagram of another cross-sectional structure of a photovoltaic cell in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 12 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 13 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0028] Explanation of reference numerals in the attached figures: 100, First substrate; 110, First surface; 120, First pyramid structure; 130, Defect portion; 140, First side surface; 150, Third pyramid structure; 101, Second substrate; 111, Second surface; 1111, First region; 1112, Second region; 121, Second pyramid structure; 131, First protrusion structure; 141, Second side surface; 151, Fourth pyramid structure; 161, Second protrusion structure; 102, Initial substrate; 103, Substrate; 113, Substrate surface; 123, Third Five-pyramid structure; 133, substrate side; 143, sixth pyramid structure; 104, passivated contact structure; 1041, first passivated contact structure; 1042, second passivated contact structure; 114, dielectric layer; 1141, first dielectric layer; 1142, second dielectric layer; 124, doped layer; 1241, first doped layer; 1242, second doped layer; 105, electrode; 115, first electrode; 125, second electrode; 40, photovoltaic cell; 41, encapsulating film; 42, cover plate; 43, solder ribbon. Detailed Implementation

[0029] As can be seen from the background technology, the morphology of the pyramid-shaped textured surface needs further study.

[0030] This disclosure provides a photovoltaic cell and its manufacturing method, as well as a photovoltaic module. In the manufacturing method, a first texturing process is performed on a first substrate with defects to remove the defects and form a second surface including a second pyramid structure and a first protrusion structure. Thus, the first protrusion structure located on the side and / or side edge of the second pyramid structure and the second pyramid structure can be considered to jointly constitute a clustered pyramid group, which facilitates the formation of more light-trapping areas, thereby improving the light-trapping effect of the second substrate. Furthermore, the clustered pyramid group makes the surface of the second substrate rougher, which is more conducive to the formation of better ohmic contact between the subsequent electrodes and the second substrate, thereby improving the photoelectric conversion efficiency of the photovoltaic cell in terms of both light utilization and conductivity. Moreover, compared to conventional textured surfaces, the clustered pyramid group formed by the second pyramid structure and the first protrusion structure has a smaller height difference or a lower degree of unevenness per unit area, which is more conducive to the formation of subsequent passivation contact structures and electrode printing. Furthermore, the clustered pyramid group makes more effective use of the gaps between adjacent second pyramid structures, increasing the density and compactness of the textured surface, reducing the reflectivity of the second substrate, and further promoting the passivation and current enhancement of photovoltaic cells, thereby improving the photoelectric performance of photovoltaic cells.

[0031] 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, "a plurality of" means two or more, unless otherwise explicitly defined.

[0032] 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.

[0033] 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.

[0034] In the description of embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[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" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[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 accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) 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 a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. 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 is it formed on a portion of the edge of the entire surface.

[0038] 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. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Additionally, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0039] 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.

[0040] 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.

[0041] This disclosure provides a method for manufacturing a photovoltaic cell according to an embodiment. The method for manufacturing a photovoltaic cell according to an embodiment of this disclosure will be described in detail below with reference to the accompanying drawings.

[0042] Reference Figures 1 to 9 , Figure 1 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 Figures 2 to 4A first substrate 100 is provided, the first substrate 100 having two first surfaces 110 opposite each other along a first direction X, the first direction X being the thickness direction of the first substrate 100; wherein at least one first surface 110 includes a first pyramid structure 120, and at least a portion of the first pyramid structure 120 has a defect portion 130 at its top.

[0043] It should be noted that, Figure 2 A scanning electron microscope image of the first surface of the first substrate in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 3 A scanning electron microscope image of a first side surface of a first substrate in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 4 This is a schematic cross-sectional view of a first substrate in a photovoltaic cell manufacturing method according to an embodiment of this disclosure. Furthermore, Figure 4 Taking the example of a first base 100 having two first surfaces 110 each including a first pyramid structure 120, in practical applications, only one first surface of the first base may include the first pyramid structure, while the other first surfaces may be formed as polished surfaces or other surface morphologies; this will be discussed later. Figure 3 and Figure 4 The first side surface of the first base is described in detail.

[0044] It is worth noting that the first substrate 100 can be considered an intermediate product in the manufacturing process of photovoltaic cells, and can be called a semi-finished substrate. Due to the numerous manufacturing steps involved in photovoltaic cells, there are many reasons why at least a portion of the tops of the first pyramid structures 120 on the first substrate 100 may have defects 130. For example, damage to the surface of the first substrate 100 resulting in debris is one cause of the defects 130. The accumulation of fine impurities on the surface of the first substrate 100 during the production process is also one cause. The defects 130 will be described in detail later with reference to embodiments. Therefore, if the defects 130 are not treated, their presence will adversely affect the quality of the film layer subsequently formed on the first pyramid structure 120, and will also adversely affect the ohmic contact between the subsequent electrodes and the first substrate 100, thereby affecting the yield of the photovoltaic cell.

[0045] S2: Refer to Figures 2 to 6 The first base 100 is subjected to a first texturing process to remove the defective portion 130, and a second pyramid structure 121 and a first protrusion structure 131 are formed on the basis of the first pyramid structure 120 to form the second base 101; wherein, the first protrusion structure 131 is located on the side and / or side edge of the second pyramid structure 121 and along the first direction X, and the height of the first protrusion structure 131 is less than the tower height of the second pyramid structure 121.

[0046] It should be noted that, Figure 5 A scanning electron microscope image of a second substrate in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 6 This is a schematic cross-sectional view of a second substrate in a photovoltaic cell manufacturing method according to an embodiment of the present disclosure. The second substrate 101 has two second surfaces 111 opposite each other along a first direction X. The second pyramid structure 121 and the first protrusion structure 131 are formed based on the first pyramid structure 120, i.e., the first surface 110 is transformed into the second surface 111 after undergoing a first texturing process. Furthermore, Figure 6 Taking the example that both second surfaces 111 of the second substrate 101 include a second pyramid structure 121 and a first protrusion structure 131, in practical applications, only one second surface may include the second pyramid structure and the first protrusion structure, and the other second surface may be formed as a polished surface or other surface morphology.

[0047] Based on this, in order to improve the yield of the final photovoltaic cell and form a second substrate 101 with a special morphology that has a better light trapping effect, the first substrate 100 is designed to undergo a first texturing process to remove the defect portion 130 and form a second surface 111 including a second pyramid structure 121 and a first protrusion structure 131. Thus, compared to the morphology of the first surface 110 of the first substrate 100, the morphology of the second surface 111 of the second substrate 101 includes not only the second pyramid structure 121 but also the first protrusion structure 131. The first protrusion structure 131 surrounds the second pyramid structure 121. Thus, the first protrusion structure 131 located on the side and / or side edge of the second pyramid structure 121 and the second pyramid structure 121 can be regarded as jointly forming a clustered pyramid group, which is conducive to forming more light-trapping areas to improve the light-trapping effect of the second surface 111 of the second substrate 101. Moreover, the clustered pyramid group makes the second surface 111 of the second substrate 101 rougher, which is more conducive to the formation of better ohmic contact between the subsequent electrode and the second substrate 101, thereby improving the photoelectric conversion efficiency of the photovoltaic cell in terms of both light utilization and conductivity. In other words, compared to conventional textured surfaces, such as the first pyramid structure 120 in the first substrate 100, the height difference within the clustered pyramid group formed by the first protrusion structure 131 on the side and / or side edge of the second pyramid structure 121 and the second pyramid structure 121 is smaller, or the unevenness per unit area is lower. This is more conducive to the formation of subsequent passivation contact structures and electrode printing. Furthermore, the clustered pyramid group makes more effective use of the gaps between adjacent second pyramid structures 121, increasing the density and compactness of the textured surface, reducing the reflectivity of the second substrate 101, and is more conducive to the passivation and current enhancement of photovoltaic cells, thereby improving the photoelectric performance of photovoltaic cells.

[0048] In addition, during the first texturing process, besides removing the defective part 130, the top of the first pyramid structure 120 can be further modified so that the top of the final second pyramid structure 121 is an arc surface.

[0049] It should be noted that the reference Figure 5 and Figure 6 At least a portion of the first protruding structures 131 can be considered as incomplete pyramid structures. For example, the first protruding structure 131 can be considered as a sheet-like pyramid structure. Along the direction from the apex to the base, the portion of the first protruding structure 131 near the base is blocked by the side and / or side edge of the second pyramid structure 121 during its extension. This results in a smaller extension area on the side of the first protruding structure 131 that contacts the second pyramid structure 121, thus presenting a first protruding structure 131 with a apex but not a complete pyramid structure overall. Furthermore, in addition to contacting the second pyramid structure 121, a portion of the first protruding structures 131 may also contact another first protruding structure 131 on the other side. In other words, at least two first protruding structures 131 can be stacked on the surface of the same second pyramid structure 121, making the first protruding structure 131 more closely resemble a sheet-like structure.

[0050] Based on this, the base size of the first protrusion structure 131 can be understood as the base size when the first protrusion structure 131 extends into a complete pyramid structure without being blocked by the second pyramid structure 121, and the base size of the first protrusion structure 131 can be smaller than the base size of the second pyramid structure 121.

[0051] The following will describe in more detail a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure, with reference to the accompanying drawings.

[0052] In some embodiments, in conjunction with reference Figure 3 and Figure 4 The first base 100 also has a first side surface 140 connecting the two first surfaces 110, the first side surface 140 including a third pyramid structure 150, and at least a portion of the third pyramid structure 150 having a defect 130 at its top; in conjunction with reference to Figures 3 to 6 In the first texturing process, the defective portion 130 is removed, and a fourth pyramid structure 151 and a second protrusion structure 161 are formed on the basis of the third pyramid structure 150; wherein, the second protrusion structure 161 is located on the side and / or side edge of the fourth pyramid structure 151, and in the direction away from the first side 140, the height of the second protrusion structure 161 is less than the height of the fourth pyramid structure 151.

[0053] It should be noted that the second base 101 also has a second side surface 141 connecting the two second surfaces 111. The fourth pyramid structure 151 and the second protrusion structure 161 are formed on the basis of the third pyramid structure 150, that is, the first side surface 140 is transformed into the second side surface 141 after undergoing the first texturing process. Furthermore, Figure 6 Taking the example that both second sides 141 of the second base 101 include a fourth pyramid structure 151 and a second protrusion structure 161, in practical applications, the second base has multiple, such as four, second sides surrounding the second surface. Depending on the requirements, only at least one second side of the second base may include the fourth pyramid structure and the second protrusion structure. Other second sides may also be formed as polished surfaces or other surface morphologies.

[0054] It is worth noting that the first substrate 100, which is an intermediate product in the process of manufacturing photovoltaic cells, may have defects 130 not only on its first surface 110, but also on its first side surface 140. This results in at least a portion of the tops of the third pyramid structures 150 on the first substrate 100 having defects 130. The reasons for the formation of defects 130 will not be elaborated here, but will be described in detail in conjunction with the embodiments later.

[0055] Based on this, in order to improve the yield of the final photovoltaic cell and form a second substrate 101 with a special morphology that has a better light-trapping effect, the first substrate 100 is designed to undergo a first texturing process to remove the defect portion 130 and form a second side surface 141 including a fourth pyramid structure 151 and a second protrusion structure 161. Thus, compared with the morphology of the first side surface 140 of the first substrate 100, the morphology of the second side surface 141 of the second substrate 101 includes not only the fourth pyramid structure 151 but also the second protrusion structure 161. The second protrusion structure 161 surrounds the fourth pyramid structure 151. Thus, the second protrusion structure 161 located on the side surface and / or side edge of the fourth pyramid structure 151 and the fourth pyramid structure 151 can be regarded as jointly forming a cluster of pyramids, which is conducive to forming more light-trapping areas and improving the light-trapping effect of the second side surface 141 of the second substrate 101.

[0056] It should be noted that the reference Figure 6At least a portion of the second protruding structures 161 can be considered as incomplete pyramid structures. For example, the second protruding structure 161 can be considered as a sheet-like pyramid structure. Along the direction from the apex to the base, the portion of the second protruding structure 161 near the base is blocked by the side and / or side edge of the fourth pyramid structure 151 during its extension. This results in a smaller extension area on the side of the second protruding structure 161 that contacts the fourth pyramid structure 151, thus presenting a second protruding structure 161 with a apex but not a complete pyramid structure overall. Furthermore, in addition to contacting the fourth pyramid structure 151, a portion of the second protruding structures 161 may also contact another second protruding structure 161 on the other side. In other words, at least two second protruding structures 161 can be stacked on the surface of the same fourth pyramid structure 151, making the second protruding structures 161 more closely resemble sheet-like structures.

[0057] Based on this, the base size of the second protrusion structure 161 can be understood as the base size when the second protrusion structure 161 extends into a complete pyramid structure without being blocked by the fourth pyramid structure 151, and the base size of the second protrusion structure 161 can be smaller than the base size of the fourth pyramid structure 151.

[0058] In some cases, refer to Figure 4 The base size of the third pyramid structure 150 can be smaller than the base size of the first pyramid structure 120.

[0059] In some cases, refer to Figure 6 The base size of the fourth pyramid structure 151 can be smaller than the base size of the second pyramid structure 121.

[0060] In some cases, refer to Figure 4 The base size of the third pyramid structure 150 is 1μm to 3μm, for example, it can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, etc. 2.9μm or 3μm, etc.; the height of the third pyramid structure 150 in the direction perpendicular to the first side 140 is 0.2μm to 1.5μm, for example, it can be 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm or 1.5μm, etc.

[0061] In some cases, refer to Figure 6Along the first direction X, the base size of the fourth pyramid structure 151 is 1μm to 4.5μm, for example, it can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm, 4μm, 4.1μm, 4.2μm. μm, 4.3μm, 4.4μm or 4.5μm, etc.; the height of the fourth pyramid structure 151 in the direction perpendicular to the second side 141 is 0.5μm to 2.5μm, for example, it can be 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm or 2.5μm, etc., wherein the direction perpendicular to the second side 141 is the same direction as the direction perpendicular to the first side 140.

[0062] The steps of providing the first substrate 100 are described in detail below through two embodiments.

[0063] In some embodiments, the step of providing the first substrate 100 may include: referencing Figure 7 Provides an initial substrate 102; in conjunction with a reference Figure 7 and Figure 8 The initial substrate 102 is subjected to a second texturing process to form a substrate 103, the substrate 103 having two substrate surfaces 113 opposite each other along a first direction X, at least one substrate surface 113 including a fifth pyramid structure 123; in conjunction with reference Figure 9 as well as Figures 2 to 4 Multiple substrates 103 are stacked or stacked and then repositioned to transform the substrates 103 into a first substrate 100.

[0064] It should be noted that, Figure 7 This is a schematic cross-sectional view of an initial substrate in a photovoltaic cell manufacturing method according to an embodiment of the present disclosure. Figure 8 This is a schematic cross-sectional view of a substrate in a photovoltaic cell manufacturing method according to an embodiment of the present disclosure. Figure 9 This is a schematic cross-sectional view of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure, showing the stacked structure of multiple substrates. Furthermore, Figure 8Taking the example that both substrate surfaces 113 of substrate 103 include a fifth pyramid structure 123, in practical applications, only one substrate surface may include a fifth pyramid structure as required, and the other substrate surface may be formed as a polished surface or other surface morphology.

[0065] It is worth noting that after the second texturing process, a fifth pyramid structure 123 with an intact apex is formed on the substrate surface 113. During the stacking or post-stack transfer steps, some of the fifth pyramid structures 123 with larger apex heights may experience wear at their apex due to compression or contact friction, generating looser debris, thus transforming the fifth pyramid structure 123 into a first pyramid structure 120. Alternatively, during the stacking or post-stack transfer steps, fine impurities may be introduced and remain on the substrate surface 113. Based on this, the defect portion 130 includes the aforementioned debris and / or impurities. Subsequently, in the first texturing process, the defect portion 130 is removed, thereby transforming the first surface 110 into the second surface 111 of the second substrate 101. This helps to prevent the presence of the defect portion 130 from affecting light trapping on the second surface 111, affecting the thickness uniformity of the film layer subsequently formed on the second surface 111, or affecting the ohmic contact between the subsequent electrode and the second surface 111, thereby avoiding a decrease in the yield of the photovoltaic cell.

[0066] Furthermore, in the stacking or post-stack transfer step, since the tips of a portion of the fifth pyramid structures 123 are worn to form the first pyramid structure 120, in the subsequent first texturing process, in addition to removing the defective portion 130, the top of the first pyramid structure 120 can be further modified so that the top of the final second pyramid structure 121 is an arc surface, thereby reducing the composite center of the second surface 111 of the second base 101.

[0067] It is understood that the substrate surface 113 formed after the second texturing process transforms into the first surface 110 after being stacked or repositioned after stacking, and the first surface 110 transforms into the second surface 111 after undergoing the first texturing process. In other words, the fifth pyramid structure 123 is formed after the second texturing process, the first pyramid structure 120 is formed on the basis of the fifth pyramid structure 123 after being stacked or repositioned after stacking, the second pyramid structure 121 and the first protrusion structure 131 are formed after the first texturing process, and the second pyramid structure 121 is formed on a portion of the first pyramid structures 120.

[0068] In some cases, in conjunction with references Figure 8 and Figure 4During the stacking or post-stack transfer steps, a portion of the tips of the fifth pyramid structures 123 are collided, resulting in debris around the tips of the fifth pyramid structures 123. The accumulation of debris forms a defect portion 130. Based on this, the thickness of the defect portion 130 located on the first surface 110 along the first direction X can be 10 nm to 500 nm.

[0069] It should be noted that the defect 130 on the first surface 110 may be formed by the collision of the apex of the fifth pyramid structure 123. Therefore, the missing portion of the first pyramid structure 120 compared to the fifth pyramid structure 123 is the defect 130. Consequently, taking the horizontal plane where the apex of the fifth pyramid structure 123 is located as the reference plane, the distance between the top of a portion of the first pyramid structures 120 and the reference plane is similar to the thickness of the defect 130. In other words, the depth of influence or friction depth of the stacking or post-stacking placement steps on the top of the fifth pyramid structure 123 is 10 nm to 500 nm.

[0070] In some examples, the thickness of the defect portion 130 located on the first surface 110 can be 10nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500nm, etc.

[0071] In some examples, during the stacking or subsequent position transfer steps, relative compression or friction occurs on the top of the fifth pyramid structure 123 with a base size greater than or equal to 3 μm to form a defect portion 130, which then transforms into the first pyramid structure 120.

[0072] In other embodiments, reference is made to Figures 2 to 6 The first base 100 also has a first side 140 including a third pyramid structure 150, at least a portion of the third pyramid structure 150 having a defect 130 at its top, and in the step of performing the first texturing process, the defect 130 is removed, and the step of providing the first base 100 based on the third pyramid structure 150 to form a fourth pyramid structure 151 and a second protrusion structure 161 may further include the following steps: refer to Figure 7 Provides an initial substrate 102; in conjunction with a reference Figure 7 and Figure 8 The initial substrate 102 is subjected to a second texturing process to form a substrate 103. The substrate 103 has two substrate surfaces 113 opposite each other along a first direction X, and a substrate side surface 133 connecting the two substrate surfaces 113. The substrate side surface 133 includes a sixth pyramid structure 143. (Reference) Figure 9Multiple substrates 103 are stacked to transform the substrates 103 into a first substrate 100. Thus, the second texturing process not only gives at least one substrate surface 113 of the substrate 103 a fifth pyramid structure 123, but also simultaneously gives the substrate side surface 133 of the substrate 103 a sixth pyramid structure 143. In this way, in the subsequent first texturing process, it is also beneficial to form a second substrate 101 that is more conducive to light trapping based on the sixth pyramid structure 143.

[0073] It should be noted that, Figure 7 Taking the example of two substrate sides 133 of substrate 103 both including a sixth pyramid structure 143, in practical applications, the substrate has multiple, such as four substrate sides, surrounding the substrate surface. Depending on the requirements, only at least one substrate side of the substrate may include a sixth pyramid structure, while other substrate sides may be formed as polished surfaces or other surface morphologies.

[0074] It is worth noting that after the second texturing process, a sixth pyramid structure 143 with an intact apex is formed on the substrate side 133. During the stacking or post-stack relocation steps, some of the taller sixth pyramid structures 143 may experience wear at their apex due to compression or contact friction, generating loose debris, thus transforming the sixth pyramid structure 143 into a third pyramid structure 150. Alternatively, during the stacking or post-stack relocation steps, fine impurities may be introduced and remain on the substrate side 133. Therefore, the defect portion 130 includes the aforementioned debris and / or impurities. Subsequently, in the first texturing process, the defect portion 130 is removed, thereby transforming the first side 140 into the second side 141 of the second substrate 101. This helps to prevent the presence of the defect portion 130 from affecting the light trapping of the second side 141 or the thickness uniformity of the film layer subsequently formed on the second side 141, thereby avoiding a decrease in the yield of the photovoltaic cell.

[0075] Furthermore, in the stacking or post-stack transfer step, since the tips of a portion of the sixth pyramid structure 143 are worn to form the third pyramid structure 150, in the subsequent first texturing process, in addition to removing the defective portion 130, the top of the third pyramid structure 150 can be further modified so that the top of the final fourth pyramid structure 151 is an arc surface, thereby reducing the composite center of the second side 141 of the second base 101.

[0076] It is understandable that the substrate side 133 formed after the second texturing process is transformed into the first side 140 after being stacked or repositioned after stacking, and the first side 140 is transformed into the second side 141 after the first texturing process. In other words, the sixth pyramid structure 143 is formed after the second texturing process, the third pyramid structure 150 is formed after being stacked or repositioned based on the sixth pyramid structure 143, and the fourth pyramid structure 151 and the second protrusion structure 161 are formed after the first texturing process, and the fourth pyramid structure 151 is formed based on a portion of the third pyramid structures 150.

[0077] In some cases, in conjunction with references Figure 8 and Figure 4 During the stacking or post-stack transfer steps, a portion of the apexes of the sixth pyramid structure 143 are collided, resulting in debris around the apexes of the sixth pyramid structure 143. The accumulation of debris forms a defect portion 130. Based on this, the thickness of the defect portion 130 on the first side surface 140 can be 5 nm to 500 nm along the direction perpendicular to the first side surface 140.

[0078] It should be noted that the defect 130 on the first side 140 may be formed by the collision of the apex of the sixth pyramid structure 143. Based on this, the missing portion of the third pyramid structure 150 compared to the sixth pyramid structure 143 is the defect 130. Therefore, taking the horizontal plane where the apex of the sixth pyramid structure 143 is located as the reference plane, the distance between the top of a portion of the third pyramid structures 150 and the reference plane is similar to the thickness of the defect 130. In other words, the depth of influence or friction depth of the stacking or post-stacking placement steps on the top of the sixth pyramid structure 143 is 5nm to 500nm.

[0079] In one example, the thickness of the defect portion 130 located on the first side surface 140 along the direction perpendicular to the first side surface 140 can be 5nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500nm, etc.

[0080] In one example, during the stacking or subsequent position transfer step, relative compression or friction is applied to the top of the sixth pyramid structure 143, whose base size is greater than or equal to 2 μm, to form a defect 130, which then transforms into the third pyramid structure 150.

[0081] In some cases, in conjunction with references Figure 8 , Figure 4 and Figure 6The base size of the second pyramid structure 121 can be greater than or equal to the base size of the fifth pyramid structure 123. It is worth noting that the stacking process or the subsequent position transfer step has little impact on the base of the fifth pyramid structure 123, so the base size of the fifth pyramid structure 123 is similar to that of the first pyramid structure 120. Furthermore, in the first texturing process, along the first direction X, in addition to modifying the top of the first pyramid structure 120, the base of the first pyramid structure 120 can be further etched to form a second pyramid structure 121 with a larger base size. Thus, the base size of the second pyramid structure 121 can be greater than or equal to the base size of the first pyramid structure 120.

[0082] In some cases, in conjunction with references Figure 8 , Figure 4 and Figure 6 The height of the second pyramid structure 121 can be greater than or equal to the height of the fifth pyramid structure 123. It is noteworthy that during the first texturing process, the first substrate 100 is etched along the first direction X on its thickness, thereby increasing the height of the formed second pyramid structure 121. Thus, the height of the second pyramid structure 121 is greater than or equal to the height of the first pyramid structure 120.

[0083] The first and second texturing processes are described in detail below.

[0084] In both embodiments described above, the first texturing process can be performed at a first production site, and the second texturing process can be performed at a second production site. It is understood that the substrate 103 (referring to the second texturing process) undergoes the second texturing process. Figure 8 The substrate 103 can also be considered a semi-finished substrate. The origin of the substrate 103 can be considered the first origin. The second substrate 101, which is formed after undergoing the first texturing process, is then referred to as the second substrate 101. Figure 6 The origin of the product is the second place of origin.

[0085] The following describes in detail the origin of the first and second texturing processes through two scenarios.

[0086] In some cases, the primary and secondary production sites can be located in different factories. It is worth noting that manufacturing photovoltaic cells requires multiple continuous processes, and the execution of these processes relies on various production equipment. The technical control of the texturing process has a significant impact on the formation of semiconductor or conductive layers in the subsequent cells, as well as the optical and electrical efficiency of the finished cells. Cell texturing is a wet process, affected by temperature, water quality, solutions, and subsequent cell connection processes. The traditional single-region centralized manufacturing model has long been limited by standardized complete production processes, making it difficult to overcome technical bottlenecks. Furthermore, the equipment linkage and process connection between the substrate or base texturing process and the cell conductive layer process are complex, with a narrow scope of coordination, resulting in a long-term inability to simultaneously improve manufacturing capacity, efficiency, and cost. On the one hand, based on limited mass production scale, the implementation method provided in one embodiment of this disclosure breaks through the limitations of single-region manufacturing to multi-regional manufacturing, which can drive the matching of equipment, raw materials, and auxiliary materials in multiple regions to adapt to the core processes, promoting technological upgrades. On the other hand, for local application scenarios in each production area, the short-chain manufacturing system allows for customized optimization of processes, significantly improving the ability to expand technology to various scenarios.

[0087] Moreover, the regional manufacturing method of wet texturing process can form a positive technology closed loop in which the core process drives the supporting technology and the supporting technology in turn supports the core process. This effect is unattainable by traditional single-region manufacturing, and ultimately improves the technical level of the entire photovoltaic cell industry chain, rather than the progress of a single link.

[0088] In addition, considering factors such as the construction costs of various production equipment (e.g., the construction costs of the same production line vary in different cities or countries, and the differences in construction costs in some regions are significant), the site requirements of various production equipment, the environmental impact of various production equipment (e.g., the standards for judging the environmental impact of a production line differ in different cities or countries, thus the handling methods of raw materials will also differ when constructing a production line), and the continuous innovation of technology, the first and second texturing processes can be designed to be carried out in different factories. In this way, while simplifying the manufacturing process of photovoltaic cells and improving the photoelectric conversion efficiency of photovoltaic cells, on the one hand, it helps to solve the problem of insufficient production lines in a single factory, enabling factories that can only perform the first texturing process to also start production; on the other hand, it facilitates the coordination between the stacking or post-stack transfer steps and the second texturing process, allowing different factories to collaborate to improve technology and increase production capacity. This represents a breakthrough from the limited mass production scale of a single region to regional manufacturing, ensuring the production efficiency of each region or factory, and the cross-regional connection and deep matching of various processes. This also reduces the construction cost of a single factory, thereby helping to reduce the manufacturing cost of photovoltaic cells.

[0089] In other cases, the primary and secondary production sites may be located in different areas of the same factory. It is worth noting that, based on the overall layout planning of a single factory, different production lines may also have a distance requiring material handling. Therefore, in conjunction with reference to... Figure 8 and Figure 9 First, multiple substrates 103 are stacked or stacked and then repositioned to transform the substrates 103 into a first substrate 100; then, in conjunction with a reference... Figures 2 to 6 The first texturing process on the first substrate 100 also helps to simplify the manufacturing process of photovoltaic cells while improving the photoelectric conversion efficiency of photovoltaic cells.

[0090] In both of the above situations, refer to Figure 8 Multiple substrates 103 are stacked in the same support structure (not shown in the figure). Before the first texturing process, the support structure carrying multiple substrates 103 is transported from the first production site to the second production site.

[0091] In some examples, the support structure carrying multiple substrates 103 can be a quartz boat, a graphite boat, or a basket. Quartz boats are mainly used in high-temperature oxidation or high-temperature annealing processes, or as external containers for graphite boats; specifically, the substrates 103 are inserted into slots in the quartz boat. Graphite boats are mainly used in diffusion or chemical vapor deposition processes; specifically, the substrates 103 are inserted into slots in the graphite boat. Baskets are mainly used in wet processes such as texturing, cleaning, and etching that require acid or alkali baths; specifically, the substrates 103 are inserted into slots in a specially designed basket, with the entire basket immersed in or passing through the acid or alkali bath.

[0092] In some embodiments, since the second substrate 101 is formed by performing a first texturing process on the substrate 103 after stacking or after position transfer, the weight of the second substrate 101 is reduced by about 0.05g to 0.35g compared with the weight of the substrate 103. For example, it can be 0.05g, 0.1g, 0.15g, 0.2g, 0.25g, 0.3g or 0.35g, etc.

[0093] In some cases, the reflectivity of the substrate surface 113 of the substrate 103 can be 7% to 12%, for example, 7%, 8%, 9%, 10%, 11% or 12%; the reflectivity of the second surface 111 formed in the second substrate 101 based on the substrate surface 113 can be 8% to 15%, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%.

[0094] The following details the process steps that may be included in the first texturing process.

[0095] In some embodiments, the step of performing the first texturing process includes at least: applying a first substrate 100 (reference) Figure 4 The process involves a first wet cleaning process and a first wet texturing process. In other words, the first texturing process includes at least a first wet cleaning process and a first wet texturing process. The first wet cleaning process cleans the first substrate 100, for example, removing dirt newly added to the surface of the first substrate 100 after stacking or relocation following stacking. The first wet texturing process removes impurities or debris generated on the surface of the first substrate 100 after stacking or relocation following stacking, and can modify the pyramidal texturing structure of the first substrate 100, for example, rounding the apex of the pyramidal texturing structure.

[0096] In some cases, after the first wet texturing process, the first texturing treatment step may also include a water washing process. For example, a pure water circulation bubbling and overflow method can be used to wash the first substrate 100 that has undergone the first wet texturing process, forming a continuous upward flow of pure water to wash away contaminants attached to its surface and continuously dilute and remove residual cleaning solution.

[0097] In some cases, after the first wet texturing process, the first texturing treatment step may also include: performing an oxidation cleaning process to clean the residual cleaning solution used in the first wet texturing process, and removing the surface damage layer of the first substrate 100 that has undergone the first wet texturing process.

[0098] In some cases, after the first wet texturing process, the first texturing treatment step may also include: performing a wet acid washing process to dilute the residual cleaning solution used in the first wet texturing process with acid, thereby achieving the purpose of cleaning the surface of the first substrate 100 that has undergone the first wet texturing process.

[0099] In one example, after the first wet texturing process, the washing process, the oxidation cleaning process, and the wet acid washing process can be performed in sequence.

[0100] In one example, after the wet pickling process, the first texturing step may further include: performing a first lifting process and a first drying process on the first substrate 100 that has undergone the wet pickling process.

[0101] In the first lifting process, a pure water overflow method can be used to slowly, uniformly, and vertically lift the first substrate 100, which has undergone the wet pickling process, out of the water tank. This cleans the residual cleaning solution on its surface and improves its hydrophobicity, thereby minimizing the risk of water stains or trace impurities remaining on its surface and achieving the purpose of cleaning its surface. In the first drying process, hot air at a temperature of 65℃~90℃, such as 65℃, 70℃, 75℃, 80℃, 85℃, or 90℃, can be used to dry the surface of the first substrate 100 that has undergone the wet pickling process. The hot air can be ozone-filtered air to reduce the risk of oxidation of the first substrate 100 after the first lifting process.

[0102] The following two examples illustrate the oxidation cleaning process in detail.

[0103] In some examples, the cleaning solution used in the oxidation cleaning process can be a mixed solution including hydrochloric acid and ozone. The hydrochloric acid can be present in a weight percentage of 0.01wt% to 3wt%, for example, 0.01wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, or 3wt%, etc.; the concentration of dissolved ozone in the mixed solution can be present in a weight percentage of 10ppm to 60ppm, for example, 10ppm, 15ppm, 20ppm, 25ppm, 30ppm, 35ppm, 40ppm, 45ppm, 50ppm, 55ppm, or 60ppm, etc.

[0104] In other examples, the cleaning solution used in the oxygen oxidation cleaning process can be a mixed solution comprising hydrofluoric acid and hydrogen peroxide. The hydrofluoric acid can be present in a weight percentage of 0.5 wt% to 10 wt%, for example, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. The hydrogen peroxide can also be present in a weight percentage of 0.5 wt% to 10 wt%, for example, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%.

[0105] The following is a detailed explanation of the wet pickling process.

[0106] In some examples, the cleaning solution used in the wet pickling process can be a mixed solution comprising hydrofluoric acid and pickling additives. The hydrofluoric acid has a weight percentage of 0.5wt% to 8wt%, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, or 8wt%, etc.; the pickling additive has a weight percentage of 0.5wt% to 5wt%, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, or 5wt%, etc.

[0107] In some embodiments, the step of performing the first texturing process includes at least the first substrate 100 (reference 100). Figure 4 Based on the first wet cleaning process and the first wet flocking process, and in conjunction with reference to... Figures 7 to 9 ,as well as Figure 4The step of providing the first substrate 100 includes at least performing a second texturing process. This second texturing process may include: performing a second wet cleaning process and a second wet texturing process. In other words, the second texturing process includes at least: performing a second wet cleaning process and a second wet texturing process on the initial substrate 102. The second wet cleaning process removes contaminants from the surface of the initial substrate 102; the second wet texturing process forms a pyramidal textured structure on at least one surface of the initial substrate 102 to form the substrate 103, and lays the foundation for the surface morphology of the subsequently formed second substrate 101.

[0108] In some cases, the initial substrate 102 undergoes a second texturing process to form a substrate 103. The weight of the substrate 103 is reduced by about 0.2g to 0.8g compared to the weight of the initial substrate 102. For example, it can be 0.2g, 0.3g, 0.4g, 0.5g, 0.6g, 0.7g, or 0.8g.

[0109] It should be noted that when designing the first texturing process, which includes the first wet cleaning process and the first wet texturing process, the second texturing process, which includes the second wet cleaning process and the second wet texturing process, can also be designed simultaneously.

[0110] The following details the process steps involved in the first and second texturing processes.

[0111] In some cases, the cleaning solution used in at least one of the first wet cleaning process and the second wet cleaning process may be a mixed solution comprising an alkali and hydrogen peroxide, wherein the alkali is sodium hydroxide or potassium hydroxide.

[0112] In some examples, in at least one of the first wet cleaning process and the second wet cleaning process, the weight percentage of alkali can be 0.1wt% to 10wt%, for example, it can be 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%, etc.; the weight percentage of hydrogen peroxide can be 0.5wt% to 10wt%, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%, etc.

[0113] It should be noted that both the first and second wet cleaning processes can use a mixed solution comprising alkali and hydrogen peroxide as the cleaning solution. In practical applications, the weight percentage of alkali in both processes can be selected from 0.1 wt% to 10 wt% according to specific requirements, and the weight percentage of hydrogen peroxide in both processes can be selected from 0.5 wt% to 10 wt% according to specific requirements. Furthermore, the relative weight percentages of alkali and hydrogen peroxide in both processes can be flexibly designed according to specific needs.

[0114] In some cases, the cleaning solution used in at least one of the first wet texturing process and the second wet texturing process may be a mixed solution comprising an alkali and a texturing additive, wherein the alkali is sodium hydroxide or potassium hydroxide.

[0115] In some examples, in at least one of the first wet texturing process and the second wet texturing process, the weight percentage of alkali can be 0.1wt% to 10wt%, for example, it can be 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%, etc.; the weight percentage of texturing additive can be 0.1wt% to 10wt%, for example, it can be 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%, etc.

[0116] It should be noted that both the first and second wet texturing processes can use a mixed solution comprising alkali and texturing additives as the cleaning solution. In practical applications, the weight percentage of alkali in both the first and second wet texturing processes can be selected from 0.1wt% to 10wt% according to specific requirements, as can the weight percentage of texturing additives in both processes.

[0117] Furthermore, the relationship between the weight percentage of alkali in the first wet texturing process and the second wet texturing process can include the following two examples: In some examples, the weight percentage of alkali in the second wet texturing process can be designed to be less than the weight percentage of alkali in the first wet texturing process. Thus, the substrate 103 (reference) is formed using the second texturing process. Figure 8 Based on the first texturing process, a cleaning solution with a higher weight percentage of alkali can be used to remove impurities or debris and round the apex of the pyramidal texturing structure of the substrate 103, while simultaneously processing the second substrate 101 (reference). Figure 6 Additional protruding structures are formed around the pyramid structure to enhance the light-trapping ability of the second substrate 101. It should be noted that the surface morphology of the second substrate 101 has been described in detail above.

[0118] In other examples, the weight percentage of alkali in the second wet texturing process may also be greater than or equal to the weight percentage of alkali in the first wet texturing process.

[0119] Furthermore, the weight percentage relationship between the texturing additives in the first and second wet texturing processes can be flexibly designed according to specific requirements.

[0120] In some examples, the process temperature of at least one of the first and second wet texturing processes can be between 55℃ and 85℃, for example, it can be 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 67℃, 68℃, 69℃, 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃, or 85℃, etc. It should be noted that in practical applications, the process temperature of both the first and second wet texturing processes can be selected within the range of 55℃ to 85℃ according to specific requirements.

[0121] In some examples, the process time of at least one of the first and second wet texturing processes can be between 100s and 800s, for example, 100s, 150s, 200s, 250s, 300s, 350s, 400s, 450s, 500s, 550s, 600s, 650s, 700s, 750s, or 800s. It should be noted that in practical applications, the process time of both the first and second wet texturing processes can be selected from 100s to 800s according to specific requirements.

[0122] The following details the other process steps that may be included in the second texturing process.

[0123] In some cases, based on the second texturing process including the second wet cleaning process and the second wet texturing process, the second texturing process may further include: processing the initial substrate 102 (referring to the first wet texturing process) that has already undergone the second wet texturing process. Figure 7 Then proceed with the second lifting process and the second drying process.

[0124] In some examples, the second lifting process can use a pure water overflow method to slowly, uniformly, and vertically lift the initial substrate 102 that has undergone the second wet texturing process out of the water tank, so as to clean the residual cleaning liquid on its surface and improve its surface hydrophobicity, thereby minimizing the risk of water stains or trace impurities remaining on the surface of the initial substrate 102 that has undergone the second wet texturing process, so as to achieve the purpose of cleaning the surface of the initial substrate 102 that has undergone the second wet texturing process.

[0125] In some examples, the second drying process may use hot air at a temperature of 65°C to 90°C, such as 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C, to dry the surface of the initial substrate 102 that has undergone the second pulling process. In one example, the hot air may be ozone-filtered air to reduce the risk of oxidation of the initial substrate 102 that has undergone the second pulling process.

[0126] In some embodiments, in conjunction with reference Figure 4 and Figure 6 The base size of the second pyramid structure 121 is greater than or equal to the base size of the first pyramid structure 120. Thus, the larger base size of the second pyramid structure 121 allows for the attachment of more first protrusions 131, resulting in a cluster of pyramids with a more uneven surface morphology. This is more conducive to improving the light-trapping effect of the second substrate 101 and to facilitating better ohmic contact between the subsequent electrodes and the second substrate 101.

[0127] In some embodiments, in conjunction with reference Figure 4 and Figure 6 The height of the second pyramid structure 121 is greater than or equal to the height of the first pyramid structure 120. Thus, the greater height of the second pyramid structure 121 facilitates the stacking of multiple first protrusions 131 on its sides and / or side edges, thereby forming a cluster of pyramids with a more uneven surface morphology. This is more conducive to improving the light-trapping effect of the second substrate 101 and to forming better ohmic contact between the subsequent electrodes and the second substrate 101.

[0128] In some embodiments, in conjunction with reference Figure 8 and Figure 4The base dimensions of both the fifth pyramid structure 123 and the first pyramid structure 120 can be from 1μm to 4.5μm, for example, they can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, or 2.3μm. 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, or 4.5μm, etc.; Reference Figure 6 The base size of the second pyramid structure 121 can be 1μm to 5μm, for example, it can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, etc. m, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3 .9μm, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm or 5μm, etc.

[0129] In some embodiments, in conjunction with reference Figure 8 and Figure 4 Along the first direction X, the height of both the fifth pyramid structure 123 and the first pyramid structure 120 can be 0.5μm to 2μm, for example, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, or 2μm, etc.; Reference Figure 6 The height of the second pyramid structure 121 can be 0.5μm to 2.5μm, for example, it can be 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm or 2.5μm, etc.

[0130] The following details other steps that may be included in the manufacturing process of photovoltaic cells.

[0131] In some embodiments, the method for manufacturing a photovoltaic cell may further include: before performing a second texturing process, texturing an initial substrate 102 (referenced) Figure 7 ( ) Perform impurity removal and cleanup treatment; In other embodiments, after the second texturing process and before the first texturing process, the substrate 103 (reference) is... Figure 8 ) or the first substrate 100 (reference) Figure 4 The substrate 101 is then subjected to impurity removal and cleaning processes, followed by a first texturing process to form the second substrate 101.

[0132] In both embodiments described above, the semiconductor structure requiring gettering is used as the gettering structure. The gettering process can include the following steps: doping the gettering structure to form a getter layer, for example, by diffusing dopant elements into the gettering structure using a high-temperature diffusion furnace. Thus, at high temperatures, the getter layer can generate an electric field or recombination centers of a certain strength, attracting and capturing impurities within the gettering structure, thereby improving the bandgap performance of the gettering structure. Furthermore, the impurity removal process can include the following steps: removing the getter layer using an acidic or alkaline etching solution.

[0133] In some cases, the material to be gettered can be 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, the material to be gettered 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 dihydrogen phosphate, perovskite, cadmium telluride, and copper indium selenide.

[0134] In some cases, the doping element can be either a p-type doping element or an n-type doping element. Specifically, the p-type doping element can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or gallium (In); the n-type doping element can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As).

[0135] In some embodiments, reference Figure 10 or Figure 11 After the first texturing process, the method for manufacturing a photovoltaic cell may further include: forming a passivation contact structure 104 on at least one surface of the second substrate 101; and forming an electrode 105 on the side of the passivation contact structure 104 away from the second substrate 101.

[0136] A passivation contact structure 104 is formed on at least one second surface 111 of the second substrate 101; an electrode 105 is formed on the side of the passivation contact structure 104 away from the second substrate 101.

[0137] It should be noted that, Figure 10 This is a schematic cross-sectional view of a photovoltaic cell in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure. Figure 11 This is a schematic cross-sectional view of another photovoltaic cell in a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure. Furthermore, to clearly illustrate the positional relationship between the passivation contact structure 104, the electrode 105, and the second substrate 101, Figure 10 and Figure 11 The textured surface morphology of any region in the second substrate 101 is not shown in the diagram. Furthermore, in practical applications, surfaces with passivated contact structures can be designed as... Figure 6 The second surface 111 shown can also be designed with a passivated contact structure as a polished surface or other surface morphology, while the other surface without a passivated contact structure is... Figure 6 The second surface 111 is shown.

[0138] In some cases, refer to Figure 10 Photovoltaic cells are cells with electrodes on both sides, such as TOPCON cells (Tunnel Oxide Passivated Contact), PERC cells (Passivated Emitter and Real Cell), and heterojunction cells (Heterojunction with Intrinsic Thin-film, abbreviated as HIT or HJT).

[0139] In some examples, the step of forming the passivated contact structure 104 includes forming a dielectric layer 114 on a second surface 111 of the second substrate 101 and forming a doped layer 124 on the side of the dielectric layer 114 away from the second substrate 101.

[0140] In one example, the photovoltaic cell is an HJT cell, the material of the dielectric layer 114 may include one or more of amorphous silicon, microcrystalline silicon or nanocrystalline silicon, the material of the doped layer 124 may include a single crystal, polycrystalline, amorphous or microcrystalline silicon material layer, and the doped layer 124 has a P-type dopant element or an N-type dopant element.

[0141] In another example, the photovoltaic cell is a TOPCON cell, the material of the dielectric layer 114 may include one or more of silicon oxide, silicon carbide, silicon nitride or silicon oxynitride, and the material of the doped layer 124 may include a single crystal, polycrystalline, amorphous or microcrystalline silicon material layer, and the doped layer 124 has a P-type dopant element or an N-type dopant element.

[0142] In both of the above examples, the step of forming electrode 105 includes: forming a first electrode 115 on the side of the doped layer 124 away from the dielectric layer 114, and forming a second electrode 125 on another second surface 111 of the second substrate 101. Furthermore, before forming the first electrode 115, a transparent conductive film may also be formed on the side of the doped layer 124 away from the dielectric layer 114.

[0143] In other cases, refer to Figure 11 Photovoltaic cells are cells with electrodes on one side only, such as BC cells (BackContact cells). BC cells include, but are not limited to, IBC cells (Interdigitated BackContact cells), HBC cells (Heterojunction Back Contact cells), TBC cells (TOPCon Back Contact cells), or HTBC cells (Hybrid Passivated Back Contact cells). HTBC cells are hybrid back contact solar cells combining heterojunction and tunnel oxide passivated contacts (abbreviated as HTBC).

[0144] In some examples, a second surface 111 of the second substrate 101 includes a first region 1111 and a second region 1112 arranged alternately along a second direction Y. The step of forming the passivation contact structure 104 includes: forming a first passivation contact structure 1041 at least on the first region 1111, the first passivation contact structure 1041 including a first dielectric layer 1141 and a first doped layer 1241 located on the side of the first dielectric layer 1141 away from the second substrate 101; and forming a second passivation contact structure 1042 at least on the second region 1112, the second passivation contact structure 1042 including a second dielectric layer 1142 and a second doped layer 1242 located on the side of the second dielectric layer 1142 away from the second substrate 101.

[0145] Furthermore, the step of forming electrode 105 includes: forming a first electrode 115 on the side of the first doped layer 1241 away from the second substrate 101; and forming a second electrode 125 on the side of the second doped layer 1242 away from the second substrate 101.

[0146] In one example, the material of at least one of the first dielectric layer 1141 and the second dielectric layer 1142 may include one or more of silicon oxide, silicon carbide, silicon nitride, and silicon oxynitride; in another example, the material of at least one of the first dielectric layer 1141 and the second dielectric layer 1142 may include one or more of amorphous silicon, microcrystalline silicon, and nanocrystalline silicon.

[0147] In summary, to improve the yield of the final photovoltaic cell and form a second substrate 101 with a special morphology that has better light-trapping effect, a first texturing process is designed to be performed on the first substrate 100 with defective portions 130. This process removes the defective portions 130 while forming a second surface 111 including a second pyramid structure 121 and a first protrusion structure 131. Thus, the first protrusion structure 131 located on the side and / or side edge of the second pyramid structure 121 and the second pyramid structure 121 can be considered to jointly constitute a clustered pyramid group, which is beneficial for forming more light-trapping areas, thereby improving the light-trapping effect of the second surface 111 of the second substrate 101. Furthermore, the clustered pyramid group makes the second surface 111 of the second substrate 101 rougher, which is more conducive to the formation of better ohmic contact between the subsequent electrodes and the second substrate 101, thereby improving the photoelectric conversion efficiency of the photovoltaic cell in terms of both light utilization and conductivity. In other words, compared to conventional textured surfaces, such as the first pyramid structure 120 in the first substrate 100, the height difference within the clustered pyramid group formed by the first protrusion structure 131 on the side and / or side edge of the second pyramid structure 121, together with the second pyramid structure 121, is smaller, or the unevenness per unit area is lower. This is more conducive to the subsequent formation of passivation contact structures and electrode printing. Furthermore, the clustered pyramid group more effectively utilizes the gaps between adjacent second pyramid structures 121, increasing the density and compactness of the textured surface, reducing the reflectivity of the second substrate 101, and further facilitating the passivation and current enhancement of photovoltaic cells, thereby improving the photoelectric performance of photovoltaic cells. In addition, in the first texturing process, besides removing the defective portion 130, the top of the first pyramid structure 120 can be further modified so that the top of the final formed second pyramid structure 121 is an arc surface, thus eliminating the need for additional rounding processing.

[0148] Another embodiment of this disclosure provides a photovoltaic cell, formed by the manufacturing method of the photovoltaic cell provided in the foregoing embodiments. The photovoltaic cell 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.

[0149] Reference Figure 6 , Figure 10 and Figure 11 The photovoltaic cell is formed by the photovoltaic cell manufacturing method provided in the foregoing embodiments.

[0150] Another embodiment of this disclosure provides a photovoltaic module, which 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.

[0151] Reference Figure 6 , Figures 11 to 13 The photovoltaic module includes: a battery string, which is formed by connecting multiple photovoltaic cells 40 provided in the foregoing embodiments, or by connecting photovoltaic cells 40 formed by the manufacturing method of multiple photovoltaic 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.

[0152] It should be noted that, Figure 12 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 13 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of this disclosure. Furthermore, Figure 12 and Figure 13 The example used here is a BC photovoltaic cell with a capacity of 40.

[0153] In some embodiments, the photovoltaic cell 40 includes, but is not limited to, one or any combination of PERC cells, BC cells, TOPCON cells, HIT / HJT cells, thin-film solar cells, and tandem cells. Among them, BC cells include, but are not limited to, IBC cells, HBC cells, TBC cells, or HTBC cells.

[0154] It should be noted that multiple photovoltaic cells 40 can be electrically connected to each other via solder strips 43. Figure 12 and Figure 13 Taking photovoltaic cell 40 as an example of a BC cell, and illustrating only one positional relationship between photovoltaic cells 40, that is, the side of each photovoltaic cell 40 with electrodes is arranged facing the same side, so that the solder ribbon 43 connects the same side of two adjacent photovoltaic cells 40 respectively. In other embodiments, the photovoltaic cells may also be arranged such that the electrodes of two adjacent photovoltaic cells are located on different sides, in which case the solder ribbon connects the different sides of the two adjacent photovoltaic cells.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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 method for manufacturing a photovoltaic cell, characterized in that, include: A first substrate is provided, the first substrate having two first surfaces opposite each other along a first direction, the first direction being the thickness direction of the first substrate; wherein at least one of the first surfaces includes a first pyramid structure, and at least a portion of the first pyramid structure has a defect at the top; The first base is subjected to a first texturing process to remove the defective portion, and a second pyramid structure and a first protrusion structure are formed on the basis of the first pyramid structure to form a second base; wherein, the first protrusion structure is located on the side and / or side edge of the second pyramid structure, and along the first direction, the height of the first protrusion structure is less than the height of the second pyramid structure.

2. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The first base also has a first side surface connecting the two first surfaces, the first side surface including a third pyramid structure, and at least a portion of the top of the third pyramid structure having the defect portion; In the first texturing process, the defective portion is removed, and a fourth pyramid structure and a second protrusion structure are formed on the basis of the third pyramid structure; wherein, the second protrusion structure is located on the side and / or side edge of the fourth pyramid structure, and in the direction away from the first side, the height of the second protrusion structure is less than the height of the fourth pyramid structure.

3. The method for manufacturing a photovoltaic cell according to claim 2, characterized in that, The base size of the third pyramid structure is smaller than that of the first pyramid structure; and / or, the base size of the fourth pyramid structure is smaller than that of the second pyramid structure.

4. The method for manufacturing a photovoltaic cell according to claim 2, characterized in that, The base size of the third pyramid structure is 1μm to 3μm, and the height of the third pyramid structure in the direction perpendicular to the first side is 0.2μm to 1.5μm; and / or, the base size of the fourth pyramid structure is 1μm to 4.5μm, and the height of the fourth pyramid structure in the direction perpendicular to the first side is 0.5μm to 2.5μm.

5. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The step of providing the first substrate includes: Provide initial substrate; The initial substrate is subjected to a second texturing process to form a substrate having two substrate surfaces opposite each other along the first direction, at least one of the substrate surfaces including a fifth pyramid structure; The substrates are stacked or the first substrate is stacked and then repositioned, so that the substrates are transformed into the first substrate.

6. The method for manufacturing a photovoltaic cell according to claim 2, characterized in that, The step of providing the first substrate includes: Provide initial substrate; The initial substrate is subjected to a second texturing process to form a substrate having two substrate surfaces opposite each other along the first direction, and a substrate side surface connecting the two substrate surfaces, the substrate side surface including a sixth pyramid structure; Multiple substrates are stacked together, such that the substrates are transformed into the first substrate.

7. The method for manufacturing a photovoltaic cell according to claim 5 or 6, characterized in that, The first texturing process is carried out at a first production site, and the second texturing process is carried out at a second production site; wherein the first production site and the second production site are located in different factories, or the first production site and the second production site are located in different areas of the same factory.

8. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The steps of performing the first texturing process include at least: performing a first wet cleaning process and a first wet texturing process on the first substrate.

9. The method for manufacturing a photovoltaic cell according to claim 8, characterized in that, After performing the first wet texturing process, the step of performing the first texturing treatment further includes: Perform a water washing process; and / or, perform an oxidation cleaning process; and / or, perform a wet pickling process.

10. The method for manufacturing a photovoltaic cell according to claim 9, characterized in that, The cleaning solution used in the oxidation cleaning process is a mixed solution of hydrochloric acid and ozone, wherein the hydrochloric acid has a weight percentage of 0.01wt% to 3wt%, and the concentration of ozone dissolved in the mixed solution is 10ppm to 60ppm. Alternatively, the cleaning solution used in the oxidation cleaning process is a mixed solution comprising hydrofluoric acid and hydrogen peroxide, wherein the weight percentage of hydrofluoric acid is 0.5wt%~10wt% and the weight percentage of hydrogen peroxide is 0.5wt%~10wt%.

11. The method for manufacturing a photovoltaic cell according to claim 9, characterized in that, The wet pickling process uses a cleaning solution that is a mixture of hydrofluoric acid and pickling additives, wherein the hydrofluoric acid has a weight percentage of 0.5wt% to 8wt% and the pickling additives have a weight percentage of 0.5wt% to 5wt%.

12. The method for manufacturing a photovoltaic cell according to claim 8, characterized in that, The step of providing the first substrate includes performing a second texturing process; wherein the step of performing the second texturing process includes performing a second wet cleaning process and a second wet texturing process.

13. The method for manufacturing a photovoltaic cell according to claim 12, characterized in that, The cleaning solution used in at least one of the first wet cleaning process and the second wet cleaning process is a mixed solution comprising an alkali and hydrogen peroxide, wherein the alkali is sodium hydroxide or potassium hydroxide; wherein the weight percentage of the alkali is 0.1wt% to 10wt% and the weight percentage of the hydrogen peroxide is 0.5wt% to 10wt%.

14. The method for manufacturing a photovoltaic cell according to claim 12, characterized in that, The cleaning solution used in at least one of the first wet texturing process and the second wet texturing process is a mixed solution comprising an alkali and a texturing additive, wherein the alkali is sodium hydroxide or potassium hydroxide; wherein the weight percentage of the alkali is 0.1wt% to 10wt%, and the weight percentage of the texturing additive is 0.1wt% to 10wt%.

15. The method for manufacturing a photovoltaic cell according to claim 14, characterized in that, The process temperature of at least one of the first wet texturing process and the second wet texturing process is 55℃~85℃; and / or, the process duration of at least one of the first wet texturing process and the second wet texturing process is 100s~800s.

16. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The base size of the second pyramid structure is greater than or equal to the base size of the first pyramid structure; and / or, the height of the second pyramid structure is greater than or equal to the height of the first pyramid structure.

17. The method for manufacturing a photovoltaic cell according to claim 1 or 16, characterized in that, The base size of the first pyramid structure is 1μm to 4.5μm, and the base size of the second pyramid structure is 1μm to 5μm; and / or, along the first direction, the height of the first pyramid structure is 0.5μm to 2μm, and the height of the second pyramid structure is 0.5μm to 2.5μm.

18. The method for manufacturing a photovoltaic cell according to claim 5 or 6, characterized in that, Before performing the second texturing process, the initial substrate is subjected to gettering and impurity removal; or, after performing the second texturing process and before performing the first texturing process, the substrate or the first base is subjected to gettering and impurity removal.

19. A photovoltaic cell, characterized in that, The photovoltaic cell is the photovoltaic cell as described in any one of claims 1 to 18.

20. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple photovoltaic cells manufactured by any one of the photovoltaic cells as described in any one of claims 1 to 18, or by connecting multiple photovoltaic 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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