Photovoltaic cell, manufacturing method thereof and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a photovoltaic cell and a manufacturing method thereof, and a photovoltaic module, and the manufacturing method comprises the steps: providing an initial cell piece; grooving the initial battery piece to form a first region with a groove and a second region without a groove on the initial battery piece; a passivation layer is formed and located on the surface, with the groove, of the initial battery piece, and the passivation layer comprises a first part located in the first area and a second part located in the second area; carrying out pre-cutting treatment on the first part and the initial battery piece so as to form cutting seams in the parts, with the grooves, of the first part and the initial battery piece; dividing the single initial battery piece into at least two photovoltaic cells, wherein each photovoltaic cell comprises a cutting edge; and forming an edge passivation layer on the cutting edge. The embodiment of the invention is at least beneficial to improving the efficiency of dividing a single initial battery piece into at least two photovoltaic cells, and reducing the damage to the photovoltaic cells.

Description

Cross-reference to related applications

[0001] This application is a divisional application of Chinese invention patent application filed on October 27, 2025, with application number 202511539723.3 and invention title "Photovoltaic Cell and Manufacturing Method Thereof, Photovoltaic Module". Technical Field

[0002] This disclosure relates to the photovoltaic field, and in particular to a photovoltaic cell and its manufacturing method, and a photovoltaic module. Background Technology

[0003] A photovoltaic module consists of multiple identical photovoltaic cells connected in series and / or parallel. The current of a single photovoltaic cell is relatively high. This high current flowing through the interconnecting elements between the photovoltaic cells of the photovoltaic module can easily lead to significant resistance loss. To improve the problem of large power loss of a single photovoltaic cell, a cutting technique is used to cut the single photovoltaic cell into half or multiple small pieces of cells. These small pieces of cells are then connected in series using conductive solder strips. The series current is lower than the current of the single cell. The decrease in current of the small pieces of cells can improve the power loss of the photovoltaic module.

[0004] However, whether lasers are used to ablate the entire photovoltaic cell, mechanical force is used to split the entire photovoltaic cell, or a combination of laser and mechanical force is used, the photovoltaic cell will be damaged during the cutting process, such as thermal damage or mechanical damage, which will lead to a reduction in the photoelectric conversion efficiency of the final split cell. Summary of the Invention

[0005] This disclosure provides a photovoltaic cell and its manufacturing method, as well as a photovoltaic module, which at least helps to improve the cutting efficiency of the cutting process and reduce the damage caused to the photovoltaic cell by the cutting process.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a method for manufacturing a photovoltaic cell, comprising: providing an initial cell; performing a grooving process on the initial cell to form a first region having grooves and a second region not having the grooves on the initial cell; forming a passivation layer on the surface of the initial cell having the grooves, the passivation layer comprising a first portion located in the first region and a second portion located in the second region; performing a pre-cutting process on the first portion and the initial cell to form a cutting slit in the portion of the first portion and the initial cell having the grooves; dividing a single initial cell into at least two photovoltaic cells, the photovoltaic cells including a cut edge; and forming an edge passivation layer on the cut edge.

[0007] In some embodiments, a green laser with a power of 1W to 30W is used to perform the pre-cutting process on the first part and the initial battery cell.

[0008] In some embodiments, the step of performing the grooving process includes: ablating the initial battery cell with an ultraviolet laser, a green laser, or an infrared laser to form the groove in the first region.

[0009] In some embodiments, the initial cell includes a doped semiconductor layer closest to the passivation layer; in the step of performing the grooving process, the groove is formed in the doped semiconductor layer, and the ratio of the groove depth in the doped semiconductor layer to the thickness of the doped semiconductor layer is 50% to 80%.

[0010] In some embodiments, the initial cell includes a doped semiconductor layer closest to the passivation layer; the thickness of the doped semiconductor layer forming the bottom surface of the groove is a reference thickness; in the pre-cutting process, the cut is also formed in the remaining doped semiconductor layer, and the ratio of the cut depth in the remaining doped semiconductor layer to the reference thickness is 30% to 60%.

[0011] In some embodiments, the density of the first part is higher than that of the second part.

[0012] In some embodiments, the defect density of the first part is higher than that of the second part.

[0013] In some embodiments, the number of nitrogen-hydrogen bonds in the first part is higher than the number of nitrogen-hydrogen bonds in the second part.

[0014] In some embodiments, the step of forming the passivation layer includes: placing the initial battery cell after the grooving process in a reaction chamber; forming the passivation layer on the first region and the second region using a deposition process, the deposition process including a first stage and a second stage connected in sequence, controlling the pressure in the reaction chamber in the first stage to gradually increase, the pressure in the reaction chamber in the second stage to be a fixed value, and the maximum pressure in the reaction chamber in the first stage being less than or equal to the pressure in the reaction chamber in the second stage.

[0015] In some embodiments, the step of forming the passivation layer includes: forming the passivation layer on the first region and the second region using a deposition process, wherein during the deposition process, the deposition temperature of the first region is controlled to be higher than that of the second region.

[0016] In some embodiments, after the grooving process is performed, the orthographic projection shape of the groove on the initial battery cell is a rectangle or a wave shape extending along a first direction.

[0017] In some embodiments, after the grooving process is performed, a plurality of the grooves are located in the same first region, and a plurality of the grooves located in the same first region are arranged in an array.

[0018] In some embodiments, a cold cutting process is used to cut the first part and the initial battery cell; wherein the cold cutting process includes a water-guided laser process.

[0019] In some embodiments, after forming the groove and before forming the passivation layer, the method for manufacturing a photovoltaic cell may further include forming a passivation film by an atomic layer deposition process.

[0020] According to some embodiments of this disclosure, another aspect of this disclosure also provides a photovoltaic cell, which is formed according to the manufacturing method of the photovoltaic cell described in any of the preceding claims.

[0021] According to some embodiments of this disclosure, another aspect of this disclosure provides a photovoltaic module, comprising: a battery string, which is formed by connecting multiple photovoltaic cells formed by the manufacturing method of photovoltaic cells as described in any one of the above claims, or formed by connecting multiple 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 facing away from the battery string.

[0022] The technical solutions provided in this disclosure have at least the following advantages: The initial solar cell is sequentially slotted, and a passivation layer is formed on the grooved surface of the initial solar cell. The first part and the initial solar cell are then pre-cut, and the single initial solar cell is divided into at least two photovoltaic cells. This process not only reduces the process parameters required for dividing the initial solar cell into at least two photovoltaic cells, thereby reducing damage to the final photovoltaic cells and improving slicing efficiency, but also, due to the combination of slotting and passivation, the grooves formed by the slotting process are passivated, and the passivation layer guides the initial solar cell to be separated at the grooves in subsequent steps, thus reducing cutting resistance in subsequent steps. Furthermore, the cutting seam formed in the pre-cutting process can serve as a positioning reference for subsequent steps and further guide the cutting path, thereby improving the cutting accuracy of subsequent steps. Moreover, passivating the cut edges can further improve the photoelectric conversion efficiency of the photovoltaic cells. Attached Figure Description

[0023] 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.

[0024] Figure 1 A process flow diagram of a method for manufacturing a photovoltaic cell according to an embodiment of this disclosure; Figure 2 This is a schematic cross-sectional view of an initial cell in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Figure 3 This is a cross-sectional schematic diagram of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure after grooving. Figure 4 for Figure 3 A top view diagram corresponding to the initial solar cell shown; Figure 5 for Figure 3 Another top view diagram corresponding to the initial battery cell shown; Figure 6 This is another top view schematic diagram of the grooving process in the manufacturing method of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 7 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure after the passivation layer has been formed. Figure 8 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure after cutting. Figure 9 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after pre-cutting. Figure 10 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after the formation of an edge passivation layer; Figure 11 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 12 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0025] Explanation of reference numerals in the attached figures: 100, Initial solar cell; 100a, Chamfer design; 110, First region; 120, Second region; 130, Doped semiconductor layer; 140, Substrate; 101, Groove; 111, Cut seam; 102, Passivation layer; 112, First section; 122, Second section; 103, Photovoltaic cell; 113, Cut edge; 104, Edge passivation layer; 41, Encapsulating film; 42, Cover plate; 43, Conductive strip. Detailed Implementation

[0026] As can be seen from the background technology, when cutting a whole photovoltaic cell, the damage caused to the photovoltaic cell during the cutting process needs to be reduced.

[0027] This disclosure provides a photovoltaic cell and its manufacturing method, as well as a photovoltaic module. In the manufacturing method, before cutting the initial cell, the initial cell is first grooved, and a passivation layer is formed on the surface of the initial cell with grooves. This not only reduces the process parameters used in subsequent cutting, thereby reducing damage to the final photovoltaic cell and improving cutting efficiency, but also, based on the combination of grooving and passivation, the grooves formed by grooving are passivated. Furthermore, the stress distribution characteristics of the passivation layer at the grooves—that is, the internal stress in the first part is higher than that in the second part, and the internal stress in the first part decreases along the direction away from the initial cell—guide the initial cell to separate at the grooves during subsequent cutting, reducing cutting resistance. Thus, the internal stress of the passivation layer further reduces the process parameters used in subsequent cutting, thereby further reducing damage and improving cutting efficiency.

[0028] In the description of the embodiments of this application, 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 and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0029] 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 application. 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.

[0030] In the description of the embodiments in this application, 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. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0031] In the description of the embodiments of this application, 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).

[0032] In the description of the embodiments of this application, 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 application 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 application.

[0033] In the description of the embodiments of this application, 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0034] In the accompanying drawings corresponding to the embodiments of this application, 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.

[0035] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components 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. Moreover, 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Reference Figures 1 to 8 , 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: S1: Reference Figure 2 , Figure 2 This is a schematic cross-sectional view of an initial cell in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure, wherein an initial cell 100 is provided.

[0040] S2: Refer to Figures 2 to 5 or in conjunction with references Figure 2 and Figure 6 The initial battery cell 100 is slotted to form a first region 110 with a groove 101 and a second region 120 without a groove 101 on the initial battery cell 100.

[0041] in, Figure 3 This is a cross-sectional schematic diagram of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure after grooving. Figure 4 for Figure 3 A top view diagram corresponding to the initial solar cell shown; Figure 5 for Figure 3 Another top view diagram corresponding to the initial battery cell shown; Figure 6 This is another top view schematic diagram of the photovoltaic cell manufacturing method provided in an embodiment of this disclosure after the grooving process. It should be noted that subsequent steps will... Figures 4 to 6 The three types of groove 101 shown are described in detail.

[0042] S3: Refer to Figure 3 and Figure 7 A passivation layer 102 is formed on the surface of the initial solar cell 100 having a groove 101. The passivation layer 102 includes a first part 112 located in a first region 110 and a second part 122 located in a second region 120. The internal stress of the first part 112 is higher than that of the second part 122, and the internal stress in the first part 112 tends to decrease along the direction of the passivation layer 102 away from the initial solar cell 100.

[0043] It should be noted that, Figure 7 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure after the passivation layer has been formed. Furthermore, in the enlarged view, the inclined surface constituting the groove 101 may be slightly inclined relative to a third direction Z, such that the groove 101... Figure 7 The cross-sectional shape shown is similar to a trapezoid. In practical applications, for the entire initial battery cell 100, the inclination of the inclined surface forming the groove 101 can be negligible. For example, the groove 101 can be made to... Figure 3 The cross-sectional shape shown is similar to a rectangle. Here, the third direction Z represents the thickness direction of the initial solar cell 100.

[0044] S4: Refer to Figure 7 and Figure 8 , Figure 8 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after a cutting process. The first part 112 and the initial cell 100 are cut to divide the single initial cell 100 into at least two photovoltaic cells 103.

[0045] Before performing step S4, i.e., cutting the initial battery cell 100, the initial battery cell 100 is first slotted. Moreover, compared with the conventional finished battery cell with a passivation layer already formed, the initial battery cell 100 designed in one embodiment of this disclosure is a semi-finished battery cell without a passivation layer. After slotting the initial battery cell 100, a passivation layer 102 is formed on the surface of the initial battery cell 100 with the groove 101. Thus, not only in step S2, grooving the initial solar cell 100 can reduce the process parameters used in subsequent cutting processes, thereby reducing the damage to the final photovoltaic cell 103 caused by cutting processes and improving the cutting efficiency, but also, based on the combination of steps S2 and S3, the passivation layer 102 can be used to passivate the groove 101 formed by the grooving process, and the stress distribution characteristics of the passivation layer 102 at the groove 101 can be used to guide the initial solar cell 100 to be separated at the groove 101 in subsequent cutting processes. Therefore, the internal stress of the passivation layer 102 can be used to further reduce the process parameters used in subsequent cutting processes and reduce the cutting resistance faced by cutting processes, thereby further reducing the damage caused by cutting processes and improving the cutting efficiency.

[0046] It is worth emphasizing that, compared to conventional finished batteries with passivation layers that only passivate the uncut portions, after first slotting the initial battery cell 100, a passivation layer 102 is formed on the surface of the initial battery cell 100 with grooves 101. The formed passivation layer 102 not only passesivates the unslotted portions of the initial battery cell 100, but also additionally passesivates the grooves 101 formed by the slotting process. Furthermore, due to the reduced surface flatness of the initial battery cell 100 caused by the groove 101, the passivation layer 102 formed in step S3 exhibits stress concentration at the groove 101. Specifically, the internal stress of the first part 112 is higher than that of the second part 122, and the internal stress in the first part 112 tends to decrease along the direction away from the initial battery cell 100 in the passivation layer 102. Therefore, it can play a stress guiding role in the subsequent cutting process in step S4, guiding the initial battery cell 100 to be separated at the groove 101 and reducing the cutting resistance faced by the cutting process, that is, assisting the cutting process to achieve the cutting of the initial battery cell 100.

[0047] Furthermore, compared to conventional laser cutting, which causes recrystallization, amorphization, or microcrack propagation within photovoltaic cells due to high temperatures, increasing the number of carrier recombination centers inside the photovoltaic cell, and is more prone to cutting path deviation, uneven cuts, chipping, or microcracks than conventional mechanical cutting, this embodiment utilizes the stress guiding effect of the passivation layer 102 at the groove 101. This reduces the process parameters used in subsequent cutting processes and guides the cutting path of the initial cell 100, thereby reducing thermal damage to the initial cell 100 caused by high temperatures and avoiding mechanical damage caused by mechanical forces. It also prevents cutting path deviation and improves the integrity of the final photovoltaic cell 103, thus improving the photoelectric conversion efficiency of the final photovoltaic cell 103. In addition, based on the pre-operation of grooving and forming the passivation layer 102, not only can the depth of the initial cell 100 to be cut be reduced during the cutting process, but the internal stress distribution characteristics of the passivation layer 102 can also reduce the cutting resistance encountered during the cutting process, thereby improving the cutting efficiency of the cutting process in multiple ways.

[0048] In some cases, based on the guiding and assisting role of the passivation layer 102 formed after the grooving process, the integrity of the photovoltaic cell 103 formed by the cutting process can be maintained at more than 90%. In other words, the loss caused by the cutting process to the initial cell 100 is very small, and there is no risk of cell cracking.

[0049] 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.

[0050] In some embodiments, in conjunction with reference Figures 4 to 6 ,as well as Figure 8 The initial solar cell 100 has chamfered corners at the four sides that are connected sequentially. After the cutting process in step S4, the photovoltaic cell 103 includes a cut edge 113. Based on this, the corners at the uncut sides of the final photovoltaic cell 103 are still chamfered at the four sides, but the corners at the cut edges 113 connected to the sides of the photovoltaic cell 103 do not have chamfered corners.

[0051] In some embodiments, in conjunction with reference Figure 7 and Figure 8In step S4, a picosecond laser can be used to cut the first part 112 and the initial battery cell 100. The laser power of the picosecond laser can be 5W to 30W, for example, it can be 5W, 6W, 7W, 8W, 9W, 10W, 11W, 12W, 13W, 14W, 15W, 16W, 17W, 18W, 19W, 20W, 21W, 22W, 23W, 24W, 25W, 26W, 27W, 18W, 19W or 30W, etc.

[0052] Picosecond lasers are ultrashort pulse lasers, and the energy generated by the laser is concentrated, allowing for cutting of the initial solar cell 100 within a short laser irradiation time. This helps reduce the duration of the thermal impact of the cutting process on the initial solar cell 100, thereby reducing thermal damage to the portion of the initial solar cell 100 near the groove 101. Moreover, compared to the conventional use of lasers with a power greater than 30W, such as 50W, to etch the entire cell, the initial solar cell 100 has already undergone grooving and the formation of a passivation layer 102 before the cutting process in step S4. With the dual assistance of the groove 101 formed by the grooving process and the stress distribution of the passivation layer 102 at the groove 101, the laser power used in the cutting process can be lower than that used in conventional cutting, for example, 2W~5W. This reduces the temperature rise of the initial solar cell 100 caused by the cutting process, thereby reducing thermal damage to the portion of the initial solar cell 100 near the groove 101.

[0053] In other embodiments, references are continued. Figure 7 and Figure 8 In step S4, a cold cutting process can be used to cut the first part 112 and the initial battery cell 100. This helps to avoid the temperature rise caused by the cutting process on the initial battery cell 100, and directly avoids thermal damage to the initial battery cell 100 caused by the cutting process. It is worth noting that, since the initial battery cell 100 has been grooved and a passivation layer 102 has been formed before the cutting process in step S4, the cutting resistance faced by the cold cutting process can be reduced by the combined assistance of the groove 101 formed by the grooving process and the stress distribution of the passivation layer 102 at the groove 101, thereby reducing the force exerted by the cold cutting process on the initial battery cell 100, and effectively avoiding the risk of the initial battery cell 100 cracking.

[0054] In some cases, cold cutting processes may include water-guided laser processes, which use an extremely fine high-pressure water jet as a "waveguide" or "optical fiber" to guide laser energy to the cutting points of the first part 112 and the initial solar cell 100.

[0055] In some embodiments, in conjunction with reference Figure 7 and Figure 9 , Figure 9 This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method according to an embodiment of the present disclosure after pre-cutting. After forming the passivation layer 102 in step S3 and before performing the cutting process in step S4, the photovoltaic cell manufacturing method may further include: pre-cutting the first part 112 and the initial cell 100 to form a cutting slit 111 in the portion of the first part 112 and the initial cell 100 opposite to the groove 101. In other words, the cutting slit 111 is formed in the portion of the first part 112 and the initial cell 100 with the groove 101. Thus, during the subsequent cutting process in step S4, not only can the internal stress distribution of the passivation layer 102 at the groove 101 guide the cutting path, but the cutting slit 111 can also serve as a positioning reference for the cutting process and further guide the cutting path, thereby improving the cutting accuracy. Moreover, the design of the cutting slit 111 can further reduce the cutting resistance faced in the subsequent cutting process, further ensuring that the initial cell 100 can be cut using lower process parameters.

[0056] Furthermore, after forming the passivation layer 102, the initial solar cell 100 is cut twice, namely, a pre-cutting process and a cutting process. This avoids damage to the initial solar cell 100 caused by the long processing time or high process parameters of a single cutting. Specifically, while ensuring that a single initial solar cell 100 is divided into at least two photovoltaic cells 103, the laser power used in both the pre-cutting and cutting processes can be controlled to be relatively low, and the processing time for both processes can be controlled to be relatively short. This reduces the temperature rise of the initial solar cell 100 and the duration of thermal impact on the initial solar cell 100, thereby reducing thermal damage to the initial solar cell 100 and improving the photoelectric conversion efficiency of the final photovoltaic cell 103.

[0057] In some cases, based on the sequential combination of grooving, stress guidance of passivation layer 102, pre-cutting and cutting, the edge damage rate of the final photovoltaic cell 103 can be reduced by at least 50% compared to conventional laser cutting or mechanical cutting processes, and the laser power used in the cutting process can be reduced by at least 60%.

[0058] In some cases, a green picosecond laser with a power of 1W to 30W can be used to pre-cut the first part 112 and the initial battery cell 100. Here, the green picosecond laser refers to a green picosecond laser.

[0059] In some examples, the laser power used for the pre-cutting process can be controlled to be 2W~5W, for example, it can be 2W, 2.5W, 3W, 3.5W, 4W, 4.5W or 5W, etc.

[0060] In some cases, refer to Figure 7 , Figure 9 and Figure 8 Before the actual cutting process, when pre-cutting the first part 112 and the initial solar cell 100, the laser power used in the pre-cutting process can be controlled to be lower than that used in the subsequent cutting process. This is to accelerate the cutting efficiency of the subsequent cutting process while minimizing the damage caused by the laser to the final photovoltaic cell 103. In one example, the laser power used in the pre-cutting process is 2W~5W, and the laser power used in the cutting process is 5W~30W.

[0061] In other cases, refer to Figure 7 and Figure 8 After the passivation layer 102 is formed, a picosecond laser with a power of 15W to 30W can be used to directly cut the initial solar cell 100. It is worth noting that, compared to cases where both pre-cutting and subsequent cutting processes are involved, when directly cutting the initial solar cell 100 with the passivation layer 102 into at least two photovoltaic cells 103, a higher laser power can be designed for the cutting process to ensure the segmentation of the initial solar cell 100. In some cases, refer to... Figure 7 The initial solar cell 100 includes a doped semiconductor layer 130 closest to the passivation layer 102 and a substrate 140 located on the side of the doped semiconductor layer 130 away from the passivation layer 102.

[0062] In some examples, the passivation layer 102 can be made of at least one of aluminum oxide, silicon nitride, silicon oxide, silicon oxynitride, silicon carbonitride, titanium oxide, or hafnium oxide; the doped semiconductor layer 130 can be made of polycrystalline silicon or amorphous silicon doped with a P-type dopant or an N-type dopant. The P-type dopant can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or gallium (In); the N-type dopant can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As).

[0063] Based on this, the passivation layer 102 and the doped semiconductor layer 130 have a large difference in hardness. Larger cutting parameters can easily lead to deviation of the cutting path or even cracking. Before cutting, at least the initial cell 100 should be grooved and passivation layer 102 should be formed. This can not only avoid using large process parameters to prevent cracking, but also guide the cutting path with the stress distribution of the passivation layer 102 in the groove 101 to form a flat cut, thereby improving the flatness of the cut surface of the final photovoltaic cell 103.

[0064] In some examples, reference Figure 7In the grooving process, a groove 101 is formed in the doped semiconductor layer 130. The ratio of the groove depth H1 to the thickness H2 of the doped semiconductor layer 130 can be 50% to 80%, for example, it can be 51%, 52%, 53%, 54%, 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%, or 80%, etc. In this way, grooving is performed only on a localized portion of the doped semiconductor layer 130, avoiding prolonged exposure to the doped semiconductor layer 130 which could lead to wafer cracking.

[0065] It should be noted that the thickness H2 of the doped semiconductor layer 130 refers to the thickness of the doped semiconductor layer 130 when the groove 101 is not formed.

[0066] In some examples, in conjunction with references Figure 7 and Figure 9 The thickness of the doped semiconductor layer 130 forming the bottom surface of the groove 101 is a reference thickness H3. In the pre-cutting process, a cutting slit 111 is also formed in the remaining doped semiconductor layer 130. The ratio of the slit depth H4 of the cutting slit 111 in the remaining doped semiconductor layer 130 to the reference thickness H3 can be 30% to 60%, for example, it can be 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%, etc. Thus, after pre-cutting the first part 112, only the local thickness of the doped semiconductor layer 130 is pre-cut to avoid the doped semiconductor layer 130 being subjected to excessively long processing time, thereby preventing the problem of chipping caused by the cutting path deviation due to the large hardness difference between the passivation layer 102 and the doped semiconductor layer 130.

[0067] It should be noted that the reference thickness H3 can be regarded as the thickness of the portion of the doped semiconductor layer 130 that is directly opposite the groove 101.

[0068] The following provides a detailed explanation of step S2, the grooving process.

[0069] In some embodiments, in conjunction with reference Figures 2 to 5 or in conjunction with references Figure 2 and Figure 6First, a photoresist mask (not shown in the figure) exposing the first region 110 can be formed on the initial cell 100. Then, a groove 101 is formed in the first region 110 by dry etching. Finally, the photoresist mask is removed.

[0070] In other embodiments, references are continued. Figures 2 to 5 or in conjunction with references Figure 2 and Figure 6 The initial battery cell 100 can be directly ablated using ultraviolet laser, green laser or infrared laser to form a groove 101 in the first region 110.

[0071] The morphology of the formed groove 101 is described in detail below.

[0072] In some embodiments, reference Figure 4 or Figure 5 After the grooving process, the orthographic projection shape of the groove 101 on the initial battery cell 100 can be a rectangle or a wave shape extending along the first direction X.

[0073] In some cases, refer to Figure 4 The orthographic projection of the groove 101 onto the initial battery cell 100 is a rectangle extending along the first direction X. Along the direction perpendicular to the first direction X, i.e., the second direction Y, the width W of the rectangle is 20μm to 50μm, for example, it can be 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm, 41μm, 42μm, 43μm, 44μm, 45μm, 46μm, 47μm, 48μm, 49μm, or 50μm, etc.

[0074] In other cases, refer to Figure 5 The orthographic projection shape of the groove 101 on the initial battery cell 100 is a wave shape extending along the first direction X. The distance D1 between the two opposite edges of the wave shape can be 20μm~50μm along the direction perpendicular to the first direction X.

[0075] In other embodiments, reference is made to... Figure 6 After the grooving process, multiple grooves 101 are located in the same first region 110, and the multiple grooves 101 located in the same first region 110 are arranged in an array. The orthographic projection shape of the groove 101 on the initial battery cell 100 can be a circle, an ellipse, a triangle or an N-sided polygon, where N is an integer greater than 3.

[0076] It should be noted that, Figure 6The example only uses the rectangular shape of the orthographic projection of the groove 101 onto the initial solar cell 100 as an example. In addition, the multiple grooves 101 arranged in an array constitute a whole area to be cut, and the first area 110 is a whole area to be cut at this time. Moreover, a single initial solar cell 100 can have at least one area to be cut, that is, a single initial solar cell 100 can be divided into two photovoltaic cells 103, or it can be divided into three, four or five photovoltaic cells 103.

[0077] In some cases, continue to refer to Figure 6 Multiple grooves 101 located in the same first region 110 are arranged in an array. Along the direction perpendicular to the first direction X, the distance D2 between the two edges of the two furthest grooves 101 can be 20μm~50μm.

[0078] The characteristics of the passivation layer 102 are described in detail below.

[0079] In some embodiments, reference Figure 7 The density of the first part 112 can be higher than that of the second part 122. It is worth noting that, compared to the lower density of the second part 122, the higher density of the first part 112 results in more pronounced stress concentration, which is more conducive to achieving higher internal stress in the first part 112 than in the second part 122. Furthermore, the lower density of the second part 122 promotes more hydrogen atom bonding within it, thus enhancing the hydrogen passivation effect of the second part 122 on the initial solar cell 100; the higher density of the first part 112 results in a lower defect density, meaning fewer pinholes or microcracks within it.

[0080] In some embodiments, reference Figure 7 The defect density of the first part 112 can be higher than that of the second part 122. It is worth noting that the defect density in the film can be characterized by the number of defects, such as pinholes and / or microcracks, contained per unit volume of the film. Furthermore, the defect density of the film is related to its compactness; generally, the lower the defect density, the higher the compactness of the film. Therefore, the defect density of the first part 112 will be higher than that of the second part 122.

[0081] In some embodiments, reference Figure 7The material of the passivation layer 102 may include at least one of silicon nitride, silicon oxynitride, or silicon carbonitride. The number of nitrogen-hydrogen bonds in the first part 112 may be lower than the number of nitrogen-hydrogen bonds in the second part 122. Thus, the first part 112 can contain more hydrogen atoms, which can provide a better hydrogen passivation effect for the initial solar cell 100. Moreover, compared to the ungrooved part of the initial solar cell 100, the part with grooves 101 formed by the grooving process will still be damaged to some extent by the grooving process. The first part 112, with a higher number of nitrogen-hydrogen bonds, is located at the grooves 101, which is beneficial for better hydrogen passivation of the part with grooves 101 in the initial solar cell 100, so as to compensate for the damage caused by the grooving process and reduce the difference in electrical performance of various regions in the final photovoltaic cell 103.

[0082] The following describes the steps for forming the passivation layer 102 in detail using silicon nitride as an example, with different embodiments.

[0083] In some embodiments, in conjunction with reference Figure 3 and Figure 7 The step of forming the passivation layer 102 may include: placing the initial battery cell 100 after grooving into the reaction chamber; forming the passivation layer 102 on the first region 110 and the second region 120 using a deposition process. The deposition process may include a first stage and a second stage connected in sequence. The pressure in the reaction chamber in the first stage is controlled to gradually increase, and the pressure in the reaction chamber in the second stage is a fixed value. The maximum pressure in the reaction chamber in the first stage is less than or equal to the pressure in the reaction chamber in the second stage.

[0084] It is worth noting that when the pressure in the reaction chamber is low, the molecular free path of the reaction gas used to form the passivation layer 102 increases, which is more conducive to the stress concentration of the passivation layer 102 formed at the groove 101. Moreover, the low pressure will cause the bombardment energy of the reaction gas to increase, making the molecules formed at the groove 101 more densely packed, which is conducive to the formation of a more dense passivation layer 102 at the groove 101.

[0085] The surface used to form the passivation layer 102 is an uneven surface with grooves 101. When the passivation layer 102 is formed on this surface, stress concentration easily occurs in the passivation layer 102 formed at the grooves 101 due to the depressions at the grooves 101, that is, the internal stress of the first part 112 is easily higher than the internal stress of the second part 122. Based on this, the pressure in the reaction chamber is designed to gradually increase in the first stage and then enter the second stage with stable pressure. This is beneficial to further promote the degree of stress concentration in the passivation layer 102 located at the grooves 101, i.e., the first part 112, in the grooves 101, in the first stage with low pressure. Moreover, as the pressure gradually increases, the internal stress of the formed passivation layer 102 tends to decrease.

[0086] In some cases, the deposition process can be PECVD (Plasma-Enhanced Chemical Vapor Deposition). It is noteworthy that in the second stage of pressure stabilization, the pressure within the reaction chamber can be the pressure used in conventional PECVD processes. This is beneficial for ensuring that the final passivation layer 102 has good overall passivation quality, building upon the unique stress distribution of the passivation layer 102 formed through the cooperation of the first and second stages. The unique stress distribution of the passivation layer 102 refers to a situation where the internal stress in the first part 112 is higher than that in the second part 122, and the internal stress in the first part 112 decreases along the direction away from the initial solar cell 100. Furthermore, with the help of this unique stress distribution of the passivation layer 102, the subsequent step S4 cutting process can achieve separation of the initial solar cell 100 using low power, thereby improving the cutting efficiency and reducing damage to the initial solar cell 100.

[0087] In some cases, the pressure in the reaction chamber during the first stage can be gradually increased from 20 Pa to 150 Pa, and the pressure in the reaction chamber during the second stage can be controlled to be 150 Pa.

[0088] It is worth noting that, based on the required variation range of the internal stress in the first part 112, the rate of pressure increase in the reaction chamber during the first stage can be adjusted. For example, in some examples, the rate of pressure increase in the reaction chamber during the first stage can be controlled to be 10 Pa / s to 20 Pa / s, such as 10 Pa / s, 11 Pa / s, 12 Pa / s, 13 Pa / s, 14 Pa / s, 15 Pa / s, 16 Pa / s, 17 Pa / s, 18 Pa / s, 19 Pa / s, or 20 Pa / s; in other examples, the rate of pressure increase in the reaction chamber during the first stage can be controlled to be 20 Pa / s to 35 Pa / s, such as 20 Pa / s, 21 Pa / s, 22 Pa / s, 23 Pa / s, 24 Pa / s, 25 Pa / s, or 26 Pa / s. The pressure increases at rates of 27 Pa / s, 28 Pa / s, 29 Pa / s, 30 Pa / s, 31 Pa / s, 32 Pa / s, 33 Pa / s, 34 Pa / s, or 35 Pa / s, etc., can be controlled to be 35 Pa / s to 50 Pa / s, for example, 35 Pa / s, 36 Pa / s, 37 Pa / s, 38 Pa / s, 39 Pa / s, 40 Pa / s, 41 Pa / s, 42 Pa / s, 43 Pa / s, 44 Pa / s, 45 Pa / s, 46 Pa / s, 47 Pa / s, 48 ​​Pa / s, 49 Pa / s, or 50 Pa / s, etc.

[0089] In some cases, when the steps of forming the passivation layer 102 include a first stage and a second stage connected sequentially, the duration of the first stage can be shorter than the duration of the second stage. The shorter duration of the first stage is mainly used to form a stress-guided initial layer. The subsequent second stage can, under this stress guidance, strengthen the stress difference between the ultimately formed first part 112 and second part 122, and guide the internal stress in the first part 112 to show a decreasing trend. The longer duration of the second stage is mainly used to efficiently and with high quality complete the deposition of the passivation layer 102. Compared to the second stage, the shorter duration of the first stage is beneficial for ensuring good overall passivation quality of the passivation layer 102 while forming a passivation layer 102 with a unique stress distribution.

[0090] In some examples, the duration of the first phase can be from 10 to 60 seconds, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 seconds; the duration of the second phase can be from 2 to 5 minutes, for example, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 seconds.

[0091] In other embodiments, in conjunction with reference to Figure 3 and Figure 7 The step of forming the passivation layer 102 may include: forming the passivation layer 102 on the first region 110 and the second region 120 using a deposition process, wherein during the deposition process, the deposition temperature of the first region 110 is controlled to be higher than that of the second region 120. In other words, in the step of forming the passivation layer 102, the surface used to form the passivation layer 102 can be temperature-controlled in different regions.

[0092] It is worth noting that increasing the deposition temperature can promote the accumulation of internal stress in the formed film, and the temperature gradient can induce stress redistribution. Based on this, designing the deposition temperature of the first region 110 to be higher than that of the second region 120 can further promote the stress concentration of the passivation layer 102, i.e., the first part 112, located in the first region 110, and further make the internal stress of the first part 112 higher than that of the second part 122. In addition, the deposition temperature of the first region 110 can be controlled to gradually decrease to ensure that the internal stress in the first part 112 shows a decreasing trend, thereby forming a passivation layer 102 with a unique stress distribution.

[0093] In some cases, the deposition process may include at least one of PECVD (Plasma Enhanced Chemical Vapor Deposition) or ALD (Atomic Layer Deposition).

[0094] In some cases, the deposition temperature of the second zone 120 can be 200℃~400℃, and the deposition temperature of the first zone 110 can be 50℃~80℃ higher than that of the second zone 120.

[0095] In some examples, the deposition temperature of the second zone 120 can be 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, or 400℃, etc.

[0096] In some examples, the difference between the deposition temperature of the first zone 110 and the deposition temperature of the second zone 120 can be 51℃, 52℃, 53℃, 54℃, 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℃, or 80℃, etc.

[0097] The following examples illustrate specific methods for controlling the deposition temperature of the first zone 110 and the second zone 120.

[0098] In some cases, the first heating device can be used to heat both the first zone 110 and the second zone 120 simultaneously, while a second heating device can be used separately to further heat the first zone 110, thereby causing the deposition temperature of the first zone 110 to be higher than that of the second zone 120. Furthermore, to control the gradual decrease in the deposition temperature of the first zone 110, the heating power of the second heating device can be designed to gradually decrease, thereby reducing the temperature rise of the first zone 110.

[0099] In yet other embodiments, in conjunction with reference to the reference Figure 3 and Figure 7 The step of forming the passivation layer 102 may include: placing the initial battery cell 100 after grooving treatment in a reaction chamber; forming the passivation layer 102 on the first region 110 and the second region 120 using a deposition process; during the deposition process, introducing a first reaction gas and a second reaction gas into the reaction chamber; the deposition process includes a first stage and a second stage connected in sequence; controlling the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the first region 110 in the first stage to be a first ratio; controlling the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the second region 120 in the first stage to be a second ratio; and controlling the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the first region 110 and the second region 120 in the second stage to be the second ratio; wherein the first ratio is less than the second ratio.

[0100] In some cases, the first reactant gas can be a nitrogen source gas, such as ammonia; the second reactant gas can be a silicon source gas, such as silane; the material of the passivation layer 102 can include at least one of silicon nitride, silicon oxynitride, or silicon carbonitride, and the ratio of the flow rates of the first reactant gas and the second reactant gas can characterize the nitrogen-silicon ratio. Based on this, the first ratio is designed to be smaller than the second ratio, that is, the nitrogen-silicon ratio in the first stage is smaller than the nitrogen-silicon ratio in the second stage.

[0101] It is worth noting that when the nitrogen-silicon ratio in the reaction chamber is low, the silicon source gas is more abundant to create a silicon-rich environment, which is more conducive to the formation of a high-density passivation layer 102. Combined with the depression at the groove 101 on the surface used to form the passivation layer 102, this helps to enhance the stress concentration of the passivation layer 102 formed at the groove 101 in the first stage, i.e., the first part 112, and can reduce the defect density of the first part 112 formed in the first stage. Furthermore, in the first stage, the surface used to form the passivation layer 102 can be subjected to regional flow control to control the flow to the second region 1 in the first stage. The ratio of the flow rates of the first and second reactant gases introduced into the first region 110 is a larger second ratio. That is, in the first stage, the nitrogen-silicon ratio introduced into the first region 110 is designed to be smaller than that introduced into the second region 120. This is because the smaller nitrogen-silicon ratio enhances the stress concentration of the first part 112, laying the foundation for the internal stress of the first part 112 to be higher than that of the second part 122. At the same time, the larger nitrogen-silicon ratio increases the nitrogen-hydrogen bond content in the second part 122 formed in the first stage, thereby improving the hydrogen passivation effect on the initial battery cell 100 in the second part 122 formed in the first stage.

[0102] Furthermore, in the subsequent second stage of the design, the nitrogen-to-silicon ratio introduced into the first region 110 and the second region 120 is relatively high, and the nitrogen source gas is more abundant to create a nitrogen-rich environment. This not only guides the internal stress in the first part 112 formed in the second stage to decrease based on the first part 112 formed in the first stage, but also promotes the final passivation layer 102 to have more nitrogen-hydrogen bonds based on the more abundant nitrogen source gas. This improves the hydrogen passivation effect of the passivation layer 102 on the initial battery cell 100, and maintains the passivation layer 102 with a moderate density to ensure that the passivation layer 102 has good toughness and avoids the problem of breakage of the passivation layer 102 in the subsequent cutting process.

[0103] In some cases, the deposition process is plasma-enhanced chemical vapor deposition (PECVD). During PECVD, the plasma power corresponding to the first region 110 in the first stage is controlled to be a first power, and the plasma power corresponding to the second region 120 in the first stage is controlled to be a second power. Furthermore, in the second stage, the plasma power corresponding to both the first region 110 and the second region 120 is the second power; wherein the first power is greater than the second power. It is worth noting that low-power plasma can reduce the bombardment damage to the film layer by high-energy particles. Designing the first power to be greater than the second power can promote stress concentration in the passivation layer 102 formed at the groove 101 in the first stage. Moreover, the second stage can not only create a nitrogen-rich environment but also reduce the bombardment damage to the already formed localized passivation layer 102, thereby improving the overall passivation effect and film quality of the final passivation layer 102.

[0104] In some examples, the flow rate of the second reactant gas introduced into the first zone 110 can be controlled to be equal to the flow rate of the second reactant gas introduced into the second zone 120. The flow rate of the first reactant gas introduced into the first zone 110 in the first stage is the first flow rate, and the flow rate of the first reactant gas introduced into the second zone 120 in the first stage is the second flow rate. The ratio of the first flow rate to the second flow rate can be 70% to 80%, for example, it can be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80%, etc.; the ratio of the first power to the second power can be 115% to 120%, for example, it can be 116%, 117%, 118%, 119%, or 120%, etc.

[0105] In one example, the second flow rate can be between 4000 sccm and 10000 sccm, for example, it can be 4000 sccm, 4500 sccm, 5000 sccm, 5500 sccm, 6000 sccm, 6500 sccm, 7000 sccm, 7500 sccm, 8000 sccm, 8500 sccm, 9000 sccm, 9500 sccm, or 10000 sccm. SCCM, etc.; the second power can be 10000W~18000W, for example, it can be 10000W, 10500W, 11000W, 11500W, 12000W, 12500W, 13000W, 13500W, 14000W, 14500W, 15000W, 15500W, 16000W, 16500W, 17000W, 17500W or 18000W, etc.

[0106] In some cases, when the step of forming the passivation layer 102 includes a first stage and a second stage connected sequentially, the duration of the first stage can be shorter than the duration of the second stage. The shorter duration of the first stage primarily lays the foundation for the internal stress of the ultimately formed first part 112 to be higher than that of the second part 122. The subsequent second stage can then strengthen the stress difference between the ultimately formed first part 112 and the second part 122 under this stress guidance, and guide the internal stress in the first part 112 to show a decreasing trend. The longer duration of the second stage is mainly used to efficiently and effectively complete the deposition of the passivation layer 102. Compared to the second stage, the shorter duration of the first stage is beneficial for forming a passivation layer 102 with a unique stress distribution while reducing plasma-induced bombardment damage, ensuring that the passivation layer 102 as a whole has good passivation quality.

[0107] In some examples, the duration of the first phase can be from 10 to 60 seconds, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 seconds; the duration of the second phase can be from 2 to 5 minutes, for example, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 seconds.

[0108] The following provides a detailed explanation of the specific method for regionally controlling the ratio of the flow rates of the first and second reactant gases in the first stage.

[0109] In some cases, during the first stage, the initial solar cell 100 with the groove 101 is movable during the deposition process, and the introduction of the first and second reactant gases is localized. Specifically, the device for introducing the first and second reactant gases into the reaction chamber may include multiple slit-type gas nozzles that respectively eject the first reactant gas, the second reactant gas, or an inert gas. The slit-type gas nozzle ejecting the first reactant gas can be used as the first gas nozzle, and the slit-type gas nozzle ejecting the second reactant gas can be used as the second gas nozzle.

[0110] By precisely controlling the moving speed of the initial battery cell 100 and synchronously specifying the flow rate of the first gas nozzle or the second gas nozzle, a low flow rate of the first gas, such as ammonia, is introduced only when the first zone 110 moves below the first gas nozzle, while a high flow rate of the first gas is introduced when the first zone 110 moves to other positions; or, a high flow rate of the second gas, such as methylsilane, is introduced only when the first zone 110 moves below the second gas nozzle, while a low flow rate of the second gas is introduced when the first zone 110 moves to other positions. Both of these adjustment methods ensure that the first ratio corresponding to the first zone 110 in the first stage is less than the second ratio corresponding to the second zone 120.

[0111] In other cases, during the first stage, in addition to using a first inlet device to simultaneously introduce a fixed flow rate of first reactant gas and second reactant gas into the first zone 110 and the second zone 120, a second inlet device containing multiple smaller gas nozzles is also used to introduce the first reactant gas or second reactant gas to locally supplement a higher flow rate of first reactant gas or second reactant gas.

[0112] In some examples, a second inlet gas can be designed to be introduced into the first reactant gas, such as ammonia, and the second inlet device is located above the second zone 120, so as to locally supplement a higher flow rate of the first reactant gas above the second zone 120 by means of the second inlet device, such that the first ratio corresponding to the first zone 110 in the first stage is less than the second ratio corresponding to the second zone 120.

[0113] In other examples, a second inlet gas, such as methylsilane, can be introduced into the second reaction gas, and the second inlet device is located above the first zone 110 to locally supplement a higher flow rate of the second reaction gas above the first zone 110, such that the first ratio corresponding to the first zone 110 in the first stage is less than the second ratio corresponding to the second zone 120.

[0114] It should be noted that in the above three embodiments, namely, the method of adjusting the pressure, deposition temperature or the ratio of the flow rate of the first and second reaction gases in the reaction chamber during the deposition process to form a passivation layer 102 with a unique stress distribution, one, two or all of the three embodiments may be present, and the choice can be made according to actual needs.

[0115] In some other embodiments, in conjunction with reference to the reference Figure 3 and Figure 7Alternatively, by rapidly switching the gas conditions throughout the reaction chamber and utilizing the difference in the adsorption and reaction rates of the reactive gases caused by the difference in surface morphology between the first region 110 and the second region 120 in the initial battery cell 100, the internal stress in the first part 112 of the final passivation layer 102 can be made higher than that in the second part 122. For example, a very short time and a high flow rate of silicon source gas or a very short time and a low flow rate of nitrogen source gas can be deposited on the entire surface used to form the passivation layer 102 to make the stress of the formed passivation film layer more concentrated in the first region 110, based on the presence of steps on the surface with grooves 101; then the flow rates of the first and second reactive gases are quickly restored to the values ​​used when forming the passivation layer 102 normally, and the internal stress in the final first part 112 can be made to decrease by finely adjusting the flow rates of the first and second reactive gases during the deposition process.

[0116] In some other embodiments, in conjunction with reference to the reference Figure 3 and Figure 7 The step of forming the passivation layer 102 may further include: placing the initial solar cell 100 after grooving treatment in a reaction chamber; forming the passivation layer 102 on the first region 110 and the second region 120 using a deposition process, the deposition process including a first stage and a second stage connected sequentially, controlling the pressure in the reaction chamber in the first stage to gradually increase, and controlling the pressure in the reaction chamber in the second stage to be a fixed value, and the maximum pressure in the reaction chamber in the first stage to be less than or equal to the pressure in the reaction chamber in the second stage. Based on the above, at least in the second stage, the deposition temperature of the first region 110 is controlled to be lower than the deposition temperature of the second region 120.

[0117] It is worth noting that lowering the deposition temperature can appropriately weaken the atomic migration ability, thereby forming a more resilient passivation layer 102, reducing the risk of overall breakage of the passivation layer 102. It can also encourage more hydrogen atoms to exist in the passivation layer 102 in the form of nitrogen-hydrogen bonds, thus improving the overall hydrogen passivation effect of the passivation layer 102. Based on this, while controlling the pressure in the reaction chamber to gradually increase in the first stage and maintaining a fixed pressure in the second stage, at least in the second stage, controlling the deposition temperature of the first region 110 to be lower than that of the second region 120 is beneficial. This leverages the synergistic effect of adjusting the pressure and deposition temperature within the reaction chamber to achieve a suitable density and good passivation effect in the passivation layer 102, while forming a passivation layer 102 with a unique stress distribution.

[0118] In some cases, at least in the second stage, the deposition temperature of the second zone 120 can be 200℃~400℃, and the deposition temperature of the first zone 110 is 25℃~40℃ lower than that of the second zone 120. It is worth noting that the adjustment range of the deposition temperature of the first zone 110 and the second zone 120 is relatively small, which is beneficial to make the pressure change in the reaction chamber have a greater impact on the internal stress in the formed passivation layer 102, so as to ensure the formation of a passivation layer 102 with a unique stress distribution.

[0119] In some examples, based on the control that the pressure in the reaction chamber gradually increases in the first stage and the pressure in the reaction chamber remains constant in the second stage, at least in the second stage, the deposition temperature of the second zone 120 can be 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, or 400℃, etc.

[0120] In some examples, based on the control that the pressure in the reaction chamber gradually increases in the first stage and the pressure in the reaction chamber is fixed in the second stage, at least in the second stage, the difference between the deposition temperature of the first zone 110 and the deposition temperature of the second zone 120 can be 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, 39℃ or 40℃, etc.

[0121] In some cases, in addition to controlling the deposition temperature of the first zone 110 in the second stage to be lower than the deposition temperature of the second zone 120, the deposition temperature of the first zone 110 in the first stage can also be further controlled to be lower than the deposition temperature of the second zone 120.

[0122] In some other embodiments, in conjunction with reference to the reference Figure 3 and Figure 7 The step of forming the passivation layer 102 may include: placing the initial battery cell 100 after grooving into the reaction chamber; forming the passivation layer 102 on the first region 110 and the second region 120 using a deposition process, the deposition process including a first stage and a second stage connected in sequence, controlling the pressure in the reaction chamber in the first stage to gradually increase, the pressure in the reaction chamber in the second stage to be a fixed value, and the maximum pressure in the reaction chamber in the first stage to be less than or equal to the pressure in the reaction chamber in the second stage.

[0123] Based on the above, during the deposition process, a first reaction gas and a second reaction gas are introduced into the reaction chamber; at least in the second stage, the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the first zone 110 is controlled to be a third ratio, and the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the second zone 120 is controlled to be a fourth ratio, and the third ratio is greater than the fourth ratio.

[0124] In some cases, the first reactant gas can be a nitrogen source gas, and the second reactant gas can be a silicon source gas; a third ratio greater than a fourth ratio, i.e., the nitrogen-silicon ratio corresponding to the first region 110 is greater than the nitrogen-silicon ratio corresponding to the second region 120, can promote the formation of more nitrogen-hydrogen bonds in the final first part 112, thereby further improving the overall hydrogen passivation effect of the passivation layer 102. Based on this, while controlling the pressure in the reaction chamber to gradually increase in the first stage and the pressure in the reaction chamber to remain constant in the second stage, at least in the second stage, controlling the nitrogen-silicon ratio corresponding to the first region 110 to be greater than the nitrogen-silicon ratio corresponding to the second region 120 is beneficial to achieve a moderate density and good passivation effect by synergistically adjusting the pressure and nitrogen-silicon ratio in the reaction chamber, based on the formation of a passivation layer 102 with a unique stress distribution.

[0125] In some cases, in addition to controlling the third ratio corresponding to the first zone 110 in the second stage to be greater than the fourth ratio corresponding to the second zone 120, it is also possible to further control the ratio of the flow rates of the first reactant gas and the second reactant gas introduced into the first zone 110 in the first stage to be the third ratio, and the ratio of the flow rates of the first reactant gas and the second reactant gas introduced into the second zone 120 to be the fourth ratio, and the third ratio is greater than the fourth ratio.

[0126] In some cases, the deposition process is plasma-enhanced chemical vapor deposition; at least in the second stage, the plasma power corresponding to the first region 110 is controlled to be lower than that corresponding to the second region 120. This helps to further reduce the bombardment damage suffered by the finally formed first part 112, thereby further improving the film quality of the finally formed passivation layer 102.

[0127] In some cases, in addition to controlling the plasma power corresponding to the first region 110 in the second stage to be lower than the plasma power corresponding to the second region 120, it is also possible to further control the plasma power corresponding to the first region 110 in the first stage to be lower than the plasma power corresponding to the second region 120.

[0128] In some cases, the ratio of the third and fourth ratios can be 110% to 115%, for example, 110%, 111%, 112%, 113%, 114%, or 115%. At least in the second stage, the ratio of the plasma power corresponding to the first region 110 to the plasma power corresponding to the second region 120 is 90% to 92.5%, for example, 90%, 90.5%, 91%, 91.5%, 92%, or 92.5%. It is worth noting that a relatively small adjustment range for the ratio of the third and fourth ratios, and a relatively small adjustment range for the difference between the plasma power corresponding to the first region 110 and the plasma power corresponding to the second region 120, both contribute to making the pressure changes within the reaction chamber have a greater impact on the internal stress in the formed passivation layer 102, thereby ensuring the formation of a passivation layer 102 with a unique stress distribution.

[0129] In the various embodiments described above, reference is made to Figure 7 Along the third direction Z, the thickness of the final passivation layer 102 can be 75nm~85nm, for example, it can be 75nm, 76nm, 77nm, 78nm, 79nm, 80nm, 81nm, 82nm, 83nm, 84nm or 85nm, etc.; the third direction Z is the thickness direction of the initial battery cell 100.

[0130] In the above embodiments, after forming the groove 101 and before forming the passivation layer 102, the method for manufacturing a photovoltaic cell may further include: forming a passivation film (not shown in the figure) by an ALD process, wherein the material of the passivation film may be aluminum oxide.

[0131] In some examples, the thickness of the alumina along the third direction Z can be 1 nm to 10 nm, for example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, etc.

[0132] In the various embodiments described above, reference is made to Figure 8 After the cutting process in step S4, the photovoltaic cell 103 includes a cutting edge 113. The manufacturing method of the photovoltaic cell may further include: performing laser annealing on the cutting edge 113 to further reduce the damage caused to the photovoltaic cell 103 by the cutting process, thereby improving the photoelectric conversion efficiency of the photovoltaic cell 103; or, in conjunction with reference to... Figure 8 and Figure 10 , Figure 10This is a partially enlarged cross-sectional view of a photovoltaic cell manufacturing method provided in an embodiment of the present disclosure after forming an edge passivation layer. After the cutting process in step S4, the photovoltaic cell 103 includes a cutting edge 113. The photovoltaic cell manufacturing method may further include: forming an edge passivation layer 104 on the cutting edge 113 to passivate the cutting edge 113 formed by the cutting process, so as to further improve the photoelectric conversion efficiency of the photovoltaic cell 103.

[0133] In summary, after grooving the initial solar cell 100, a passivation layer 102 is formed on the surface of the initial solar cell 100 with the groove 101. Thus, not only in step S2, grooving the initial solar cell 100 reduces the process parameters used in subsequent cutting processes, thereby reducing damage to the final photovoltaic cell 103 and improving cutting efficiency, but also, based on the combination of steps S2 and S3, the passivation layer 102 can passivate the groove 101 formed by the grooving process, and the stress distribution characteristics of the passivation layer 102 at the groove 101 can guide the initial solar cell 100 to separate at the groove 101 during subsequent cutting. Therefore, the internal stress of the passivation layer 102 can further reduce the process parameters used in subsequent cutting processes, thereby further reducing damage caused by cutting and improving cutting efficiency.

[0134] 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 now be described in detail with reference to the accompanying drawings.

[0135] refer to Figure 8 or Figure 10 The photovoltaic cell 103 is formed according to the photovoltaic cell manufacturing method described in any of the above claims, which is beneficial to improving the photoelectric conversion efficiency of the photovoltaic cell 103.

[0136] Another embodiment of this disclosure provides a photovoltaic module, including a photovoltaic cell formed by the manufacturing method of the photovoltaic cells provided in the foregoing embodiments, or a photovoltaic cell provided in the foregoing embodiments. The photovoltaic module provided in another embodiment of this disclosure will be described 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.

[0137] Reference Figures 1 to 12 A photovoltaic module includes: a battery string, which is formed by connecting multiple photovoltaic cells 103 formed by the manufacturing method of photovoltaic cells provided in the foregoing embodiments, or formed by connecting multiple photovoltaic cells 103 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.

[0138] in, Figure 11 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 12 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0139] In some embodiments, the photovoltaic cell 103 includes, but is not limited to, one or any combination of PERC cells (Passivated Emitter Rear Cell), IBC cells (Interdigitated Back Contact), TOPCon cells (Tunnel Oxide Passivated Contact), HIT / HJT cells (Heterojunction Technology), thin-film solar cells, and tandem cells. Thin-film solar cells include, but are not limited to, perovskite thin-film solar cells, copper indium selenide (CIGS) thin-film solar cells, gallium arsenide (GaAs) thin-film solar cells, and cadmium sulfide (CdS) thin-film solar cells. Tandem cells include, but are not limited to, perovskite cells stacked with crystalline silicon cells, perovskite cells stacked with perovskite cells, and perovskite cells stacked with thin-film cells.

[0140] In some embodiments, the photovoltaic cell 103 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0141] In some embodiments, the photovoltaic cells 103 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 103 can be a single cell or a sliced ​​cell, where a sliced ​​cell refers to a cell formed by cutting a complete single cell.

[0142] In some embodiments, in conjunction with reference Figure 11 and Figure 12 Multiple photovoltaic cells 103 can be electrically connected through conductive strips 43. Figure 11 and Figure 12This illustration only shows one positional relationship between photovoltaic cells 103, where the electrodes of the photovoltaic cells 103 with the same polarity are arranged in the same direction, or in other words, the electrodes of each photovoltaic cell 103 with positive polarity are arranged facing the same side, so that the conductive strip 43 connects different sides of two adjacent photovoltaic cells 103 respectively. In other embodiments, the photovoltaic cells can also be arranged with electrodes of different polarities facing the same side, that is, the electrodes of multiple adjacent photovoltaic cells are arranged in the order of first polarity, second polarity, and first polarity respectively, then the conductive strip connects the same side of two adjacent photovoltaic cells.

[0143] In some embodiments, there may be no gap between adjacent photovoltaic cells, that is, adjacent photovoltaic cells may overlap each other.

[0144] 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 103, and the second encapsulating layer covers the other of the front or back sides of the photovoltaic cell 103. Specifically, at least one of the first encapsulating layer or the second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first encapsulating layer or the second encapsulating layer can also be an EP film, EPE film, or PVP film. Among them, 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, and EVA film; and PVP film refers to a co-extruded film formed by stacking POE film, EVA film, and 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.

[0145] 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.

[0146] 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.

[0147] In some embodiments, the photovoltaic cell 103 may be a cell with a main grid or a cell without a main grid.

[0148] 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: Provide initial battery cells; The initial battery cell is slotted to form a first region with grooves and a second region without grooves on the initial battery cell; A passivation layer is formed on the surface of the initial battery cell having the groove, the passivation layer comprising a first portion located in the first region and a second portion located in the second region; The first part and the initial battery cell are pre-cut to form a cutting slit in the portion of the first part and the initial battery cell that has the groove; The initial solar cell is divided into at least two photovoltaic cells, each photovoltaic cell including a cut edge; An edge passivation layer is formed at the cut edge.

2. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The pre-cutting process of the first part and the initial battery cell is achieved by using a green laser with a laser power of 1W to 30W.

3. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The grooving process includes: using an ultraviolet laser, green laser, or infrared laser to ablate the initial battery cell to form the groove in the first region.

4. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The initial solar cell includes a doped semiconductor layer closest to the passivation layer; in the step of performing the grooving process, the groove is formed in the doped semiconductor layer, and the ratio of the groove depth in the doped semiconductor layer to the thickness of the doped semiconductor layer is 50% to 80%.

5. The method for manufacturing a photovoltaic cell according to claim 1 or 4, characterized in that, The initial solar cell includes a doped semiconductor layer closest to the passivation layer; the thickness of the doped semiconductor layer forming the bottom surface of the groove is a reference thickness; in the pre-cutting process, the cutting seam is also formed in the remaining doped semiconductor layer, and the ratio of the cutting seam depth in the remaining doped semiconductor layer to the reference thickness is 30% to 60%.

6. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The density of the first part is higher than that of the second part.

7. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The defect density of the first part is higher than that of the second part.

8. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The number of nitrogen-hydrogen bonds in the first part is lower than the number of nitrogen-hydrogen bonds in the second part.

9. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The steps for forming the passivation layer include: The initial battery cell, after undergoing the aforementioned grooving process, is placed in the reaction chamber; The passivation layer is formed on the first region and the second region using a deposition process. The deposition process includes a first stage and a second stage connected in sequence. The pressure in the reaction chamber in the first stage is controlled to gradually increase, while the pressure in the reaction chamber in the second stage is a fixed value. The maximum pressure in the reaction chamber in the first stage is less than or equal to the pressure in the reaction chamber in the second stage.

10. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The steps for forming the passivation layer include: The passivation layer is formed on the first region and the second region using a deposition process. During the deposition process, the deposition temperature of the first region is controlled to be higher than that of the second region.

11. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, After the grooving process is performed, the orthographic projection shape of the groove on the initial battery cell is a rectangle or a wave shape extending along the first direction.

12. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, After the grooving process is performed, multiple grooves are located in the same first area, and multiple grooves located in the same first area are arranged in an array.

13. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, The first part and the initial battery cell are cut using a cold cutting process; wherein, the cold cutting process includes water-guided laser technology.

14. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, After the groove is formed but before the passivation layer is formed, the method for manufacturing a photovoltaic cell may further include forming a passivation film by an atomic layer deposition process.

15. A photovoltaic cell, characterized in that, The photovoltaic cell is formed by the method of manufacturing a photovoltaic cell according to any one of claims 1 to 14.

16. 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 14, or by connecting multiple photovoltaic cells as described in claim 15; 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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