Photovoltaic cell and method of manufacturing the same, photovoltaic module

Abstract

The embodiment of 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 comprises: providing an initial cell piece; performing groove processing on the initial cell piece to form a first region with a groove and a second region without a groove on the initial cell piece; forming a passivation layer on the surface with the groove in the initial cell piece; wherein the passivation layer comprises a first part in the first region and a second part in the second region, the internal stress of the first part is higher than that of the second part, and the internal stress in the first part decreases in the direction away from the initial cell piece along the passivation layer; and performing cutting processing on the first part and the initial cell piece to divide a single initial cell piece into at least two photovoltaic cells. The embodiment of the present disclosure is at least beneficial to improve the cutting efficiency of the cutting processing and reduce the damage caused by the cutting processing to the photovoltaic cell.

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] 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.

[0003] 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

[0004] 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 to the photovoltaic cell caused by the cutting process.

[0005] 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 with grooves and a second region without grooves on the initial cell; forming a passivation layer located on the surface of the initial cell having the grooves; wherein the passivation layer includes a first portion located in the first region and a second portion located in the second region, the internal stress in the first portion is higher than the internal stress in the second portion, and the internal stress in the first portion tends to decrease along the direction of the passivation layer away from the initial cell; and performing a cutting process on the first portion and the initial cell to divide a single initial cell into at least two photovoltaic cells.

[0006] In some embodiments, a picosecond laser is used to perform the cutting process on the first part and the initial battery cell, and the laser power of the picosecond laser is 5W~30W; or, a cold cutting process is used to perform the cutting process on the first part and the initial battery cell.

[0007] In some embodiments, after forming the passivation layer, before performing the cutting process, the method further comprises: performing a pre-cutting process on the first part and the initial battery piece to form a cutting seam in a portion of the first part and the initial battery piece that is directly opposite to the groove.

[0008] In some embodiments, the initial battery piece comprises a doped semiconductor layer closest to the passivation layer; in the step of performing the slotting process, the groove is formed in the doped semiconductor layer, and a ratio of a groove depth of the groove in the doped semiconductor layer to a thickness of the doped semiconductor layer is 50% to 80%; a thickness of the doped semiconductor layer constituting a bottom surface of the groove is a reference thickness; in the step of performing the pre-cutting process, the cutting seam is also formed in the remaining doped semiconductor layer, and a ratio of a seam depth of the cutting seam in the remaining doped semiconductor layer to the reference thickness is 30% to 60%.

[0009] In some embodiments, the first part has a higher density than the second part; and / or, the first part has a higher defect density than the second part; and / or, the first part has a lower number of N-H bonds than the second part.

[0010] In some embodiments, the step of forming the passivation layer comprises: placing the initial battery piece after the slotting process in a reaction chamber; and forming the passivation layer on the first region and the second region by using a deposition process, the deposition process comprising a first stage and a second stage connected in sequence, the pressure in the reaction chamber in the first stage being gradually increased, the pressure in the reaction chamber in the second stage being 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.

[0011] In some embodiments, the pressure in the reaction chamber in the first stage is gradually increased from 20 Pa to 150 Pa, and the pressure in the reaction chamber in the second stage is 150 Pa.

[0012] In some embodiments, the step of forming the passivation layer comprises: forming the passivation layer on the first region and the second region by using a deposition process, and in the process of performing the deposition process, the deposition temperature of the first region is higher than the deposition temperature of the second region.

[0013] In some embodiments, the deposition temperature of the second region is 200°C to 400°C, and the deposition temperature of the first region is 50°C to 80°C higher than the deposition temperature of the second region.

[0014] In some embodiments, the step of forming the passivation layer comprises: placing the initial battery piece after the slotting treatment into a reaction chamber; forming the passivation layer on the first region and the second region by a deposition process, in which a first reaction gas and a second reaction gas are introduced into the reaction chamber during the deposition process, the deposition process comprises a first stage and a second stage connected in sequence, the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the first region in the first stage is a first ratio, the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the second region in the first stage is a second ratio, and the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the first region and the second region in the second stage is the second ratio; wherein the first ratio is less than the second ratio.

[0015] In some embodiments, the deposition process is a plasma enhanced chemical vapor deposition process; in which the plasma power corresponding to the first region in the first stage is a first power, the plasma power corresponding to the second region in the first stage is a second power, and the plasma power corresponding to the first region and the second region in the second stage is the second power; wherein the first power is greater than the second power.

[0016] In some embodiments, the flow rate of the second reaction gas introduced into the first region is equal to the flow rate of the second reaction gas introduced into the second region, and the flow rate of the first reaction gas introduced into the first region in the first stage is a first flow rate, the flow rate of the first reaction gas introduced into the second region in the first stage is a second flow rate, and the ratio of the first flow rate to the second flow rate is 70% to 80%; the ratio of the first power to the second power is 115% to 120%.

[0017] In some embodiments, the step of forming the passivation layer comprises: forming the passivation layer on the first region and the second region by a deposition process, the deposition process comprises a first stage and a second stage connected in sequence; wherein the duration of the first stage is 10 seconds to 60 seconds, and the duration of the second stage is 2 minutes to 5 minutes.

[0018] In some embodiments, after the cutting treatment, the photovoltaic cell comprises a cutting edge; the method for manufacturing the photovoltaic cell further comprises: performing a laser annealing treatment on the cutting edge; or forming an edge passivation layer on the cutting edge.

[0019] In some embodiments, the shape of the projection of the groove on the initial battery piece is a rectangle extending along a first direction, or a wave shape extending along a first direction; or, a plurality of the grooves are located in the same first region, and the plurality of the grooves located in the same first region are arranged in an array.

[0020] In some embodiments, the shape of the projection of the groove on the initial battery piece is a rectangle extending along a first direction, and the width of the rectangle along a direction perpendicular to the first direction is 20-50 μm; or, the shape of the projection of the groove on the initial battery piece is a wave shape extending along a first direction, and the distance between the opposite edges of the wave shape along a direction perpendicular to the first direction is 20-50 μm; or, a plurality of the grooves are located in the same first region, and the plurality of the grooves located in the same first region are arranged in an array, and the distance between the edges of the two grooves farthest apart along a direction perpendicular to the first direction is 20-50 μm.

[0021] According to some embodiments of the present disclosure, another aspect of the embodiments of the present disclosure further provides a photovoltaic cell formed according to the manufacturing method of the photovoltaic cell of any one of the above.

[0022] According to some embodiments of the present disclosure, still another aspect of the embodiments of the present disclosure further provides a photovoltaic module, comprising: a cell string connected by a plurality of photovoltaic cells formed according to the manufacturing method of the photovoltaic cell of any one of the above, or connected by a plurality of the photovoltaic cells of the above; an encapsulant film for covering the surface of the cell string; and a cover plate for covering the surface of the encapsulant film away from the cell string.

[0023] The technical solutions provided by the embodiments of the present disclosure have at least the following advantages:

[0024] Before the cutting treatment of the initial battery piece, the initial battery piece is sequentially subjected to the groove processing, and a passivation layer is formed on the surface of the initial battery piece with the groove. In this way, not only can the groove processing of the initial battery piece reduce the process parameters of the subsequent cutting treatment, thereby reducing the damage caused by the cutting treatment to the final photovoltaic cell and improving the cutting efficiency of the cutting treatment, but also, based on the cooperation of the groove processing and the formation of the passivation layer, the groove formed by the groove processing can be passivated by the passivation layer, and the stress distribution characteristics of the passivation layer at the groove, i.e., the internal stress of the first part is higher than that of the second part, and the internal stress in the first part decreases in the direction away from the initial battery piece of the passivation layer, can guide the initial battery piece to be separated at the groove in the subsequent cutting treatment and reduce the cutting resistance faced by the cutting treatment, so that the internal stress of the passivation layer can be further used to reduce the process parameters of the subsequent cutting treatment, thereby further reducing the damage caused by the cutting treatment and improving the cutting efficiency of the cutting treatment. BRIEF DESCRIPTION OF DRAWINGS

[0025] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which demonstrate aspects of the embodiments. Such illustrations are not limiting of the embodiments unless otherwise specified, and do not pose a limitation on the scope of the disclosure. For clarity, conventional techniques related to making or using the devices or processes described herein have not been described in detail to avoid unnecessarily obscuring the description of the embodiments. As shown, the drawings provide one or more embodiments of the disclosure.

[0026] Figure 1 A process flow diagram of a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0027] Figure 2 A cross-sectional view of an initial cell according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0028] Figure 3 A cross-sectional view after slotting according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0029] Figure 4 A top view of an initial cell according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure; Figure 3

[0030] A top view of an initial cell according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure; Figure 5 Figure 3 A top view after slotting according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0031] Figure 6 A partial enlarged cross-sectional view after forming a passivation layer according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0032] Figure 7 A partial enlarged cross-sectional view after cutting according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0033] Figure 8 A partial enlarged cross-sectional view after pre-cutting according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0034] Figure 9 A partial enlarged cross-sectional view after forming an edge passivation layer according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;

[0035] Figure 10 A partial enlarged cross-sectional view after forming an edge passivation layer according to a method for manufacturing a photovoltaic cell according to an embodiment of the disclosure;​

[0036] Figure 11 A partial perspective view of a cell string in a photovoltaic module according to yet another embodiment of the present disclosure is provided;

[0037] Figure 12 A partial cross-sectional view of a photovoltaic module according to yet another embodiment of the present disclosure is provided.

[0038] Explanation of reference signs:

[0039] 100, initial cell piece; 100a, chamfer design; 110, first region; 120, second region; 130, doped semiconductor layer; 140, substrate; 101, groove; 111, cutting seam; 102, passivation layer; 112, first part; 122, second part; 103, photovoltaic cell; 113, cutting edge; 104, edge passivation layer; 41, encapsulation film; 42, cover plate; 43, conductive tape. DETAILED DESCRIPTION

[0040] As can be known from the background, the damage caused to the photovoltaic cell during the cutting process needs to be reduced when the whole photovoltaic cell is cut.

[0041] The embodiments of the present disclosure provide a photovoltaic cell and a manufacturing method thereof, and a photovoltaic module. In the manufacturing method, before the initial cell piece is cut, the initial cell piece is sequentially subjected to a slotting process, and a passivation layer is formed on the surface of the initial cell piece having the groove. In this way, not only can the slotting process of the initial cell piece reduce the process parameters used in the subsequent cutting process, thereby reducing the damage caused by the cutting process to the final photovoltaic cell and improving the cutting efficiency of the cutting process, but also based on the cooperation of the slotting process and the formation of the passivation layer, the groove formed by the slotting process can be passivated by the passivation layer, and the stress distribution characteristics of the passivation layer at the groove, i.e., the internal stress of the first part is higher than that of the second part, and along the direction of the passivation layer away from the initial cell piece, the internal stress in the first part tends to decrease, guiding the initial cell piece to be separated at the groove in the subsequent cutting process and reducing the cutting resistance faced by the cutting process, so that the internal stress of the passivation layer can be further used to reduce the process parameters used in the subsequent cutting process, thereby further reducing the damage caused by the cutting process and improving the cutting efficiency of the cutting process.

[0042] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0043] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments.

[0044] In the description of the embodiments of the application, the term“and / or” only means an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists, A and B exist, and B exists. In addition, the character“ / ” herein generally means that the front and rear associated objects are in an“or” relationship.

[0045] In the description of the embodiments of the application, the term“a plurality of” refers to two or more (including two), and similarly, “a plurality of groups” refers to two or more groups (including two groups), and “a plurality of pieces” refers to two or more pieces (including two pieces).

[0046] In the description of the embodiments of the application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application.

[0047] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connection”,“connection”,“fixing” and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the application can be understood according to the specific circumstances.

[0048] In the drawings corresponding to the embodiments of the present application, the thickness and area of the layers are exaggerated for clarity and ease of description. When it is described that one component (such as a layer, a film, a region, or a substrate) is on or on the surface of another component, the component can be "directly" on the surface of the other component, or a third component can exist between the two components. On the contrary, when it is described that one component is on the surface of another component or one component surface forms or is provided with another component, it means that there is no third component between the two components. In addition, when it is described that one component is "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 part of the edge of the entire surface.

[0049] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can also be further included. In addition, when a layer, a film, a region, or a plate, etc. component is referred to as "on / over" another component, it can be "directly on" another component (i.e. between the surface of another component and another component without other components), or another component can exist therebetween. In addition, when a layer, a film, a region, a plate, etc. component is "directly on" another component, or when a layer, a film, a region, a plate, etc. component is on the surface of another component, it means that there is no other component therebetween.

[0050] The terms used in the description of various described embodiments herein are only used to describe specific embodiments, and are not intended to be limiting. As used in the description of various described embodiments and the appended claims, "the component" is also intended to include the plural form, unless the context clearly indicates otherwise. Among them, the components include layers, films, regions, or plates, etc.

[0051] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present disclosure, many technical details are presented in order to enable the reader to better understand the embodiments of the present disclosure. However, the technical solutions claimed by the embodiments of the present disclosure can be implemented even without these technical details and based on various changes and modifications of the following embodiments.

[0052] An embodiment of the present disclosure provides a manufacturing method of a photovoltaic cell, which will be described in detail below with reference to the accompanying drawings.

[0053] Combined with reference Figures 1 to 8 , Figure 1 A process flow chart of the manufacturing method of the photovoltaic cell provided by an embodiment of the present disclosure, the manufacturing method of the photovoltaic cell at least includes:

[0054] S1: Reference Figure 2 ,Figure 2 A cross-sectional view of an initial cell wafer in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure is provided, and an initial cell wafer 100 is provided.

[0055] S2: refer to Figures 2 to 5 , refer to Figure 2 and Figure 6 The initial cell wafer 100 is subjected to a slotting process to form a first region 110 having a groove 101 and a second region 120 without the groove 101 on the initial cell wafer 100.

[0056] Wherein, Figure 3 A cross-sectional view of an initial cell wafer in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure is provided, and an initial cell wafer 100 is provided. Figure 4 As Figure 3 A top view schematic diagram corresponding to the initial cell wafer shown; Figure 5 As Figure 3 Another top view schematic diagram corresponding to the initial cell wafer shown; Figure 6 A top view schematic diagram of the initial cell wafer after the slotting process in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. It should be noted that the three groove 101 morphologies shown in Figures 4 to 6 will be described in detail later.

[0057] S3: refer to Figure 3 and Figure 7 , a passivation layer 102 is formed on the surface of the initial cell wafer 100 having the groove 101; wherein the passivation layer 102 includes a first part 112 located in the first region 110 and a second part 122 located in the 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 decreases in the direction of the passivation layer 102 away from the initial cell wafer 100.

[0058] It should be noted that, Figure 7 A partial enlarged cross-sectional view of the initial cell wafer after the passivation layer is formed in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. In addition, in the enlarged schematic diagram, the inclined surface constituting the groove 101 can be slightly inclined with respect to the third direction Z, so that the cross-sectional morphology of the groove 101 in the cross-sectional view shown in Figure 7 is similar to a trapezoid. In actual application, for the entire initial cell wafer 100, the inclination of the inclined surface constituting the groove 101 can also be negligible, for example, so that the cross-sectional morphology of the groove 101 in the cross-sectional view shown in Figure 3 is similar to a rectangle. Wherein, the third direction Z is the thickness direction of the initial cell wafer 100.

[0059] S4: refer to Figure 7 and Figure 8 , Figure 8A partial enlarged sectional view of the photovoltaic cell manufacturing method provided by an embodiment of the present disclosure after the cutting process is shown in FIG. 2. The first portion 112 and the initial cell sheet 100 are cut to divide the single initial cell sheet 100 into at least two photovoltaic cells 103.

[0060] Before the cutting process of step S4 is performed on the initial cell sheet 100, the initial cell sheet 100 is first subjected to the slotting process. In addition, compared with the finished whole cell sheet that has formed a passivation layer, the initial cell sheet 100 designed in the embodiment of the present disclosure is a semi-finished whole cell sheet that has not formed a passivation layer. The passivation layer 102 is formed on the surface of the initial cell sheet 100 having the groove 101 after the slotting process is performed on the initial cell sheet 100. In this way, not only the slotting process of step S2 performed on the initial cell sheet 100 can reduce the process parameters used in the subsequent cutting process, thereby reducing the damage caused by the cutting process to the final photovoltaic cell 103 and improving the cutting efficiency of the cutting process, but also based on the cooperation of step S2 and step S3, the groove 101 formed by the slotting process can be passivated by the passivation layer 102, and the stress distribution characteristics of the passivation layer 102 at the groove 101 can guide the initial cell sheet 100 to be separated at the groove 101 in the subsequent cutting process, so that the process parameters used in the subsequent cutting process can be further reduced and the cutting resistance faced by the cutting process can be reduced by the internal stress of the passivation layer 102, thereby further reducing the damage caused by the cutting process and improving the cutting efficiency of the cutting process.

[0061] It is worth emphasizing that, compared with the passivation layer in the finished whole cell sheet that has formed a passivation layer, the passivation layer 102 only plays a passivation effect on the part that is not cut. After the slotting process is performed on the initial cell sheet 100, the passivation layer 102 is formed on the surface of the initial cell sheet 100 having the groove 101. The passivation layer 102 formed in this way not only plays a passivation effect on the initial cell sheet 100 at the part that is not slotted, but also plays an additional passivation effect on the groove 101 formed by the slotting process. In addition, based on the reduction of the surface flatness of the initial cell sheet 100 caused by the groove 101, the passivation layer 102 formed in step S3 has a stress concentration phenomenon at the groove 101. Specifically, the internal stress of the first portion 112 is higher than that of the second portion 122, and the internal stress in the first portion 112 decreases along the direction of the passivation layer 102 away from the initial cell sheet 100. Therefore, the passivation layer 102 can play a stress guiding role when the cutting process of step S4 is performed subsequently, guide the initial cell sheet 100 to be separated at the groove 101, and reduce the cutting resistance faced by the cutting process, that is, assist the cutting process to cut the initial cell sheet 100.

[0062] Further, compared with the high temperature caused by the conventional laser cutting, the re-crystallization, amorphization or micro-crack propagation in the photovoltaic cell, the increase of the carrier recombination center in the photovoltaic cell, and the easy to cause the cutting path deviation, the uneven incision, the edge collapse or the hidden crack caused by the conventional mechanical cutting, the stress guiding effect of the passivation layer 102 at the groove 101 in the embodiment of the present disclosure can reduce the process parameters used in the subsequent cutting process, and can guide the cutting path of the initial cell piece 100, so as to reduce the thermal damage caused by the high temperature to the initial cell piece 100, avoid the mechanical damage caused by the mechanical force to the initial cell piece 100, and avoid the deviation of the cutting path and improve the integrity of the photovoltaic cell 103 formed finally, thereby improving the photoelectric conversion efficiency of the photovoltaic cell 103 formed finally. In addition, based on the pre-operation of the slotting processing and forming the passivation layer 102, not only the depth of the initial cell piece 100 required for cutting in the cutting process can be reduced, but also the cutting resistance faced by the cutting process can be reduced by means of the internal stress distribution characteristics of the passivation layer 102, thereby improving the cutting efficiency of the cutting process in many aspects.

[0063] In some cases, based on the guiding and assisting effect of the passivation layer 102 formed after the slotting processing, the integrity of the photovoltaic cell 103 finally formed through the cutting processing can be maintained at more than 90%, in other words, the loss of the initial cell piece 100 caused by the cutting processing is very small, and there is no risk of cracking.

[0064] The manufacturing method of the photovoltaic cell provided by the embodiment of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0065] In some embodiments, in combination with reference to Figures 4 to 6 , and Figure 8 , the corners of the four sides of the initial cell piece 100 connected in turn are chamfered 100a; after the cutting processing in step S4, the photovoltaic cell 103 includes a cutting edge 113. Based on this, the corners of the side surfaces connected in turn in the photovoltaic cell 103 formed finally still have the chamfered design 100a, but the corners of the cutting edge 113 connected with the side surfaces in the photovoltaic cell 103 do not have the chamfered design.

[0066] In some embodiments, in combination with reference to Figure 7 and Figure 8In step S4, the first part 112 and the initial battery sheet 100 can be cut by a picosecond laser. The laser power of the picosecond laser can be 5W-30W, for example, 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.

[0067] The picosecond laser is an ultrashort pulse laser. The energy generated by the laser is concentrated, so that the cutting of the initial battery sheet 100 can be realized in a short laser irradiation time, thereby reducing the heat impact of the cutting process on the initial battery sheet 100 and reducing the thermal damage to the part of the initial battery sheet 100 close to the groove 101. Moreover, compared with the conventional etching of the whole battery by a laser with a power greater than 30W, for example, 50W, since the initial battery sheet 100 has been sequentially subjected to the slotting process and the formation of the passivation layer 102 before the cutting process in step S4, the laser power used in the cutting process can be smaller than that used in the conventional cutting, for example, 2W-5W, thereby reducing the temperature rise of the initial battery sheet 100 caused by the cutting process and reducing the thermal damage to the part of the initial battery sheet 100 close to the groove 101.

[0068] In some embodiments, the first part 112 and the initial battery sheet 100 can be cut by a cold cutting process. Figure 7 and Figure 8 In step S4, the first part 112 and the initial battery sheet 100 can be cut by a cold cutting process. In this way, it is beneficial to avoid the temperature rise of the initial battery sheet 100 caused by the cutting process and directly avoid the thermal damage to the initial battery sheet 100 caused by the cutting process. It is worth noting that since the initial battery sheet 100 has been sequentially subjected to the slotting process and the formation of the passivation layer 102 before the cutting process in step S4, the cutting resistance faced by the cold cutting process can be reduced, thereby reducing the force exerted on the initial battery sheet 100 by the cold cutting process, and effectively avoiding the risk of cracking of the initial battery sheet 100.

[0069] In some cases, the cold cutting process can include a water-guided laser process, that is, a very fine high-pressure water jet is used as a "waveguide" or "optical fiber" to guide the transfer of laser energy to the part to be cut of the first part 112 and the initial battery sheet 100.

[0070] In some embodiments, in combination with reference to Figure 7 andFigure 9 , Figure 9 A partial enlarged sectional view of the photovoltaic cell after the pre-cutting process in the manufacturing method of the photovoltaic cell provided by an embodiment of the present disclosure is shown. After the step S3 of forming the passivation layer 102, before the step S4 of cutting, the manufacturing method of the photovoltaic cell can further include: performing a pre-cutting process on the first part 112 and the initial cell piece 100 to form a cutting seam 111 in the first part 112 and the part of the initial cell piece 100 opposite to the groove 101. In this way, when the step S4 of cutting is subsequently performed, not only the stress distribution of the passivation layer 102 at the groove 101 can guide the cutting path, but the cutting seam 111 can also serve as a positioning reference for the cutting process and further guide the cutting path, thereby improving the cutting accuracy of the cutting process. Moreover, the design of the cutting seam 111 can further reduce the cutting resistance faced by the subsequent cutting process, so as to further ensure that the cutting of the initial cell piece 100 can be achieved by using lower process parameters.

[0071] In addition, after the passivation layer 102 is formed, the initial cell piece 100 is cut twice, i.e., the pre-cutting process and the cutting process, which can avoid damage to the initial cell piece 100 caused by long time consumption or high process parameters of single cutting. Specifically, on the basis of ensuring that the single initial cell piece 100 is divided into at least two photovoltaic cells 103, the laser power used in the pre-cutting process and the cutting process can be controlled to be small, and the time consumption of the pre-cutting process and the cutting process can be controlled to be short, so as to reduce the temperature rise amplitude of the initial cell piece 100 and reduce the heat influence time on the initial cell piece 100, thereby reducing the thermal damage to the initial cell piece 100, and further improving the photoelectric conversion efficiency of the photovoltaic cell 103 finally formed.

[0072] In some cases, based on the cooperation of the slotting process, the stress guidance of the passivation layer 102, the pre-cutting process and the cutting process, compared with the conventional laser cutting process or mechanical cutting process, the edge damage rate of the photovoltaic cell 103 finally formed can be reduced by at least 50%, and the laser power used in the cutting process can be reduced by at least 60%.

[0073] In some cases, the pre-cutting process on the first part 112 and the initial cell piece 100 can be implemented by using a green skin laser with a laser power of 1 W to 30 W. The green skin laser refers to a green picosecond laser.

[0074] In some examples, the laser power used in the pre-cutting process can be controlled to be 2 W to 5 W, for example, 2 W, 2.5 W, 3 W, 3.5 W, 4 W, 4.5 W or 5 W, etc.

[0075] In some cases, in combination with the description of the pre-cutting process in the manufacturing method of the photovoltaic cell provided by the embodiment of the present disclosure, the cutting process can be implemented by using a green skin laser with a laser power of 1 W to 30 W. Figure 7 , Figure 9 andFigure 8 In the pre-cutting process before the cutting process, the laser power used in the pre-cutting process can be controlled to be less than the laser power used in the subsequent cutting process, so as to accelerate the cutting efficiency of the subsequent cutting process and reduce the damage of the laser to the final photovoltaic cell 103 as much as possible. 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.

[0076] In other cases, in combination with reference to Figure 7 and Figure 8 After the formation of the passivation layer 102, the initial wafer 100 can be directly cut by using a picosecond laser with a laser power of 15W-30W. It is worth noting that, compared with the case where both the pre-cutting process and the subsequent cutting process exist, when the initial wafer 100 formed with the passivation layer 102 is directly cut into at least two photovoltaic cells 103, the laser power of the cutting process can be designed to be larger to ensure the segmentation of the initial wafer 100. In some cases, in combination with reference to Figure 7 , the initial wafer 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.

[0077] In some examples, the material of the passivation layer 102 can be at least one of aluminum oxide, silicon nitride, silicon oxide, silicon oxynitride, silicon oxycarbonitride, titanium oxide or hafnium oxide; the material of the doped semiconductor layer 130 can be polycrystalline silicon or amorphous silicon doped with a P-type doping element or an N-type doping element. The P-type doping element can be at least one of boron (B) element, aluminum (Al) element, gallium (Ga) element or indium (In) element; the N-type doping element can be at least one of phosphorus (P) element, bismuth (Bi) element, antimony (Sb) element or arsenic (As) element.

[0078] Therefore, the hardness of the passivation layer 102 and the doped semiconductor layer 130 is quite different, and the larger the cutting parameter value is, the more likely the cutting path deviates or even cracks. Before the cutting process, at least the initial wafer 100 is subjected to the slotting process and the passivation layer 102 is formed, which not only avoids the large process parameter value of the cutting process to avoid cracking, but also guides the cutting path by the stress distribution of the passivation layer 102 in the groove 101 to form a smooth cut, thereby improving the flatness of the cutting surface of the final photovoltaic cell 103.

[0079] In some examples, in combination with reference to 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The following provides a detailed explanation of step S2, the grooving process.

[0084] In some embodiments, in conjunction with reference Figures 2 to 5 or in conjunction with references Figure 2 and Figure 6The photoresist mask (not shown in the figure) exposing the first area 110 can be formed on the initial battery sheet 100 first, then the groove 101 is formed at the first area 110 by dry etching, and finally the photoresist mask is removed.

[0085] In some embodiments, the groove 101 is formed by the following method. Figures 2 to 5 In some embodiments, the groove 101 is formed by the following method. Figure 2 In some embodiments, the groove 101 is formed by the following method. Figure 6 In some embodiments, the groove 101 is formed by the following method.

[0086] The shape of the groove 101 formed is described in detail below.

[0087] In some embodiments, the groove 101 is formed by the following method. Figure 4 In some embodiments, the groove 101 is formed by the following method. Figure 5 In some embodiments, the groove 101 is formed by the following method.

[0088] In some embodiments, the groove 101 is formed by the following method. Figure 4 In some embodiments, the groove 101 is formed by the following method.

[0089] In some embodiments, the groove 101 is formed by the following method. Figure 5 In some embodiments, the groove 101 is formed by the following method.

[0090] In some embodiments, the groove 101 is formed by the following method. Figure 6 In some embodiments, the groove 101 is formed by the following method.

[0091] In some embodiments, the groove 101 is formed by the following method. 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.

[0092] 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.

[0093] The characteristics of the passivation layer 102 are described in detail below.

[0094] 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.

[0095] 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.

[0096] In some embodiments, reference Figure 7The material of the passivation layer 102 can include at least one of silicon nitride, silicon oxynitride, or silicon oxycarbonitride, and the number of hydrogen-nitrogen bonds in the first portion 112 can be higher than that in the second portion 122. In this way, the first portion 112 can contain more hydrogen atoms, which can provide better hydrogen passivation for the initial battery wafer 100. In addition, the portion of the initial battery wafer 100 having the groove 101 is also damaged by the slotting process, and the first portion 112 having a higher number of hydrogen-nitrogen bonds is located at the groove 101, which is conducive to better hydrogen passivation for the portion of the initial battery wafer 100 having the groove 101 to offset the damage caused by the slotting process, so as to reduce the difference in electrical performance of each region of the photovoltaic cell 103 finally formed.

[0097] The following takes silicon nitride as an example of the material of the passivation layer 102, and the steps of forming the passivation layer 102 are described in detail by using different embodiments.

[0098] In some embodiments, in combination with reference to Figure 3 and Figure 7 The step of forming the passivation layer 102 can include: placing the initial battery wafer 100 after the slotting process in a reaction chamber; and using a deposition process to form the passivation layer 102 on the first region 110 and the second region 120. The deposition process can include a first stage and a second stage connected in sequence. The pressure in the reaction chamber in the first stage is gradually increased, and the pressure in the reaction chamber in the second stage is a fixed value. In addition, 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.

[0099] It is worth noting that when the pressure in the reaction chamber is low, the free path of the molecules of the reaction gas used to form the passivation layer 102 increases, which is conducive to causing the passivation layer 102 formed at the groove 101 to form stress concentration. In addition, low pressure can promote the bombardment energy of the reaction gas to increase, so that the molecules formed at the groove 101 are more densely packed, thereby facilitating the formation of a passivation layer 102 having a higher density at the groove 101.

[0100] The surface for forming the passivation layer 102 is a rough surface with the grooves 101, and when the passivation layer 102 is formed on the surface, the passivation layer 102 formed at the grooves 101 is prone to stress concentration, i.e., prone to making the internal stress of the first part 112 higher than the internal stress of the second part 122, based on the recess at the grooves 101. On this basis, the pressure in the reaction chamber in the first stage is gradually increased, and then enters the second stage of stable pressure, which is conducive to further promoting the stress concentration degree of the passivation layer 102 at the grooves 101, i.e., the first part 112 in the first stage of low pressure, and with the gradual increase of the pressure, the internal stress of the formed passivation layer 102 shows a decreasing trend.

[0101] In some cases, the deposition process can be a PECVD (Plasma Enhanced Chemical Vapor Deposition) process. It is worth noting that in the second stage of stable pressure, the pressure in the reaction chamber can be the pressure used in the conventional PECVD process, which is conducive to ensuring that the finally formed passivation layer 102 has good passivation quality as a whole on the basis of forming a passivation layer 102 with a unique stress distribution by means of the cooperation of the first stage and the second stage. Among them, the passivation layer 102 with a unique stress distribution refers to: 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 shows a decreasing trend along the direction of the passivation layer 102 away from the initial battery piece 100. Moreover, with the help of such a passivation layer 102 with a unique stress distribution, the subsequent step S4 cutting process can use low power to realize the separation of the initial battery piece 100, so as to improve the cutting efficiency of the cutting process and reduce the damage to the initial battery piece 100.

[0102] In some cases, the pressure in the reaction chamber in the first stage can be gradually increased from 20 Pa to 150 Pa, and the pressure in the reaction chamber in the second stage is 150 Pa.

[0103] It is worth noting that, based on the requirement of the change range of the internal stress of the first part 112, the rising rate of the pressure in the reaction chamber in the first stage can be adjusted. For example, in some examples, the rising rate of the pressure in the reaction chamber in the first stage can be controlled to be 10 Pa / s-20 Pa / s, for example, it can be 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, 20 Pa / s; in other examples, the rising rate of the pressure in the reaction chamber in the first stage can be controlled to be 20 Pa / s-35 Pa / s, for example, it can be 20 Pa / s, 21 Pa / s, 22 Pa / s, 23 Pa / s, 24 Pa / s, 25 Pa / s, 26 Pa / s, 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.; in yet other examples, the rising rate of the pressure in the reaction chamber in the first stage can be controlled to be 35 Pa / s-50 Pa / s, for example, it can be 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.

[0104] In some cases, when the step of forming the passivation layer 102 includes a first stage and a second stage in sequence, the duration of the first stage can be shorter than the duration of the second stage. The first stage with shorter duration is mainly used to form a stress-guided initial layer, and the subsequent second stage can strengthen the stress difference between the first part 112 and the second part 122 under the stress guidance, and guide the internal stress in the first part 112 to show a decreasing trend; the second stage with longer duration is mainly used to efficiently and high-quality complete the deposition of the passivation layer 102; compared with the second stage, the first stage with shorter duration is beneficial to ensure that the passivation layer 102 has good passivation quality as a whole while forming a passivation layer 102 with a unique stress distribution.

[0105] In some examples, the first stage can last for 10-60 seconds, for example, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds, or 60 seconds, etc.; the second stage can last for 2-5 minutes, for example, 120 seconds, 130 seconds, 140 seconds, 150 seconds, 160 seconds, 170 seconds, 180 seconds, 190 seconds, 200 seconds, 210 seconds, 220 seconds, 230 seconds, 240 seconds, 250 seconds, 260 seconds, 270 seconds, 280 seconds, 290 seconds, or 300 seconds, etc.

[0106] In some other embodiments, in combination with reference to Figure 3 and Figure 7 The step of forming the passivation layer 102 can include forming the passivation layer 102 on the first region 110 and the second region 120 by a deposition process, in which 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 for forming the passivation layer 102 can be controlled in temperature in regions.

[0107] It is worth noting that the increase of the deposition temperature can promote the accumulation of internal stress in the formed film layer, and the temperature gradient can induce the redistribution of stress. Based on this, the design of the deposition temperature of the first region 110 being higher than that of the second region 120 can further promote the stress concentration degree of the passivation layer 102 located at the first region 110, i.e., the first part 112, and further promote the internal stress of the first part 112 to be 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 presents a decreasing trend, thereby forming a passivation layer 102 with a unique stress distribution.

[0108] In some cases, the deposition process can include at least one of a PECVD (Plasma Enhanced Chemical Vapor Deposition) process or an ALD (Atomic Layer Deposition) process.

[0109] In some cases, the deposition temperature of the second region 120 can be 200-400°C, and the deposition temperature of the first region 110 can be 50-80°C higher than that of the second region 120.

[0110] In some examples, the deposition temperature of the second region 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.

[0111] In some examples, the difference between the deposition temperature of the first region 110 and the deposition temperature of the second region 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.

[0112] The following illustrates a specific method of controlling the deposition temperature of the first region 110 and the deposition temperature of the second region 120.

[0113] In some cases, the first heating device can be used to heat the first region 110 and the second region 120 at the same time, and the second heating device can be additionally used to further heat the first region 110 alone, so as to cause the deposition temperature of the first region 110 to be higher than the deposition temperature of the second region 120. In addition, in order to control the deposition temperature of the first region 110 to gradually decrease, the heating power of the second heating device can be designed to gradually decrease, so as to reduce the heating amplitude of the first region 110.

[0114] In yet some embodiments, in combination with the reference of Figure 3 and Figure 7 The step of forming the passivation layer 102 can include: placing the initial battery piece 100 after the slotting treatment in a reaction chamber; using a deposition process to form the passivation layer 102 on the first region 110 and the second region 120, in the process of the deposition process, the first reaction gas and the second reaction gas are introduced into the reaction chamber, the deposition process includes a first stage and a second stage connected in sequence, 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 is a first ratio, 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 is a second ratio, and 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 is the second ratio; wherein the first ratio is less than the second ratio.

[0115] In some cases, the first reaction gas can be a nitrogen source gas, such as ammonia; the second reaction gas can be a silicon source gas, such as monosilane; the material of the passivation layer 102 can include at least one of silicon nitride, silicon oxynitride, or silicon oxycarbonitride; and the ratio of the flow rates of the first reaction gas and the second reaction gas can characterize a nitrogen-to-silicon ratio. Based on this, the first ratio is designed to be less than the second ratio, i.e., the nitrogen-to-silicon ratio in the first stage is less than the nitrogen-to-silicon ratio in the second stage.

[0116] Notably, when the nitrogen-to-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 forming the passivation layer 102 with a higher density, and the recessing of the surface for forming the passivation layer 102 at the groove 101 is conducive to strengthening the stress concentration of the passivation layer 102 formed at the groove 101 in the first stage, i.e., the first portion 112, and can reduce the defect density of the first portion 112 formed in the first stage. In addition, in the first stage, the flow of the surface for forming the passivation layer 102 can be controlled in a region-by-region manner to control the ratio of the flow rates of the first reaction gas and the second reaction gas into the second region 120 in the first stage to be a larger second ratio, i.e., the nitrogen-to-silicon ratio into the first region 110 is designed to be less than the nitrogen-to-silicon ratio into the second region 120 in the first stage. This not only strengthens the stress concentration of the first portion 112 by means of the smaller nitrogen-to-silicon ratio, lays the foundation for the internal stress of the first portion 112 to be higher than that of the second portion 122, but also improves the nitrogen-hydrogen bond content in the second portion 122 formed in the first stage by means of the larger nitrogen-to-silicon ratio, to improve the hydrogen passivation effect of the initial battery piece 100 in the second portion 122 formed in the first stage.

[0117] Further, the nitrogen-to-silicon ratio into the first region 110 and the second region 120 in the subsequent second stage is designed to be higher, and the nitrogen source gas is more abundant to create a nitrogen-rich environment, which not only guides the internal stress in the first portion 112 formed in the second stage to decrease based on the first portion 112 formed in the first stage, but also promotes the passivation layer 102 formed finally to have more nitrogen-hydrogen bonds based on the more abundant nitrogen source gas, to improve the hydrogen passivation effect of the initial battery piece 100 in the passivation layer 102, and to keep the passivation layer 102 as a whole to have a moderate density, to ensure that the passivation layer 102 as a whole has good toughness, to avoid the problem of breaking of the passivation layer 102 in the subsequent cutting process.

[0118] In some cases, the deposition process is a plasma enhanced chemical vapor deposition process; during the plasma enhanced chemical vapor deposition process, the plasma power corresponding to the first region 110 in the first stage is controlled to be a first power, the plasma power corresponding to the second region 120 in the first stage is controlled to be a second power, and the plasma power corresponding to the first region 110 and the second region 120 in the second stage is controlled to be the second power; wherein the first power is greater than the second power. It is worth noting that a low-power plasma can reduce the bombardment damage of high-energy particles to the film layer, and by designing the first power to be greater than the second power, the stress concentration of the passivation layer 102 formed at the groove 101 in the first stage can be promoted, and the second stage not only creates a nitrogen-rich environment, but also reduces the bombardment damage to the locally formed passivation layer 102, so as to improve the passivation effect and film layer quality of the finally formed passivation layer 102 as a whole.

[0119] In some examples, the flow rate of the second reaction gas introduced into the first region 110 can be controlled to be equal to the flow rate of the second reaction gas introduced into the second region 120, and the flow rate of the first reaction gas introduced into the first region 110 in the first stage is a first flow rate, the flow rate of the first reaction gas introduced into the second region 120 in the first stage is a second flow rate, and 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.

[0120] In one example, the second flow rate can be 4000sccm to 10000sccm, for example, it can be 4000sccm, 4500sccm, 5000sccm, 5500sccm, 6000sccm, 6500sccm, 7000sccm, 7500sccm, 8000sccm, 8500sccm, 9000sccm, 9500sccm or 10000sccm, etc.; the second power can be 10000W to 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.

[0121] In some cases, when the step of forming the passivation layer 102 comprises a first stage and a second stage in sequence, the duration of the first stage can be shorter than the duration of the second stage. The first stage with shorter duration is mainly used to lay the foundation for the internal stress of the first part 112 to be higher than the internal stress of the second part 122, and the subsequent second stage can strengthen the stress difference between the first part 112 and the second part 122 under the guidance of the stress, and guide the internal stress in the first part 112 to show a decreasing trend; the second stage with longer duration is mainly used to efficiently and high-quality complete the deposition of the passivation layer 102; compared with the second stage, the first stage with shorter duration is conducive to forming a passivation layer 102 with a unique stress distribution, and can reduce the damage caused by plasma bombardment, and ensure that the passivation layer 102 has good passivation quality as a whole.

[0122] In some examples, the duration of the first stage can be 10 seconds to 60 seconds, for example, can be 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds or 60 seconds, etc.; the duration of the second stage can be 2 minutes to 5 minutes, for example, can be 120 seconds, 130 seconds, 140 seconds, 150 seconds, 160 seconds, 170 seconds, 180 seconds, 190 seconds, 200 seconds, 210 seconds, 220 seconds, 230 seconds, 240 seconds, 250 seconds, 260 seconds, 270 seconds, 280 seconds, 290 seconds or 300 seconds, etc.

[0123] The specific method of controlling the ratio of the flow rates of the first reaction gas and the second reaction gas in the first stage is described in detail below.

[0124] In some cases, in the first stage, the initial battery piece 100 formed with the groove 101 is moving during the deposition process, and the introduction of the first reaction gas and the second reaction gas is localized in the region. Specifically, the equipment for introducing the first reaction gas and the second reaction gas into the reaction chamber can include a plurality of slit gas nozzles for spraying the first reaction gas, the second reaction gas or inert gas, respectively. The slit gas nozzle for spraying the first reaction gas can be used as the first gas nozzle, and the slit gas nozzle for spraying the second reaction gas can be used as the second gas nozzle.

[0125] By precisely controlling the moving speed of the initial battery piece 100 and synchronously specifying the flow rate of the first gas nozzle or the second gas nozzle, the low flow rate of the first gas, such as ammonia, is only allowed to pass through when the first zone 110 moves under the first gas nozzle, while the first gas nozzle is controlled to pass through the high flow rate of the first gas when the first zone 110 moves to other positions; or the high flow rate of the second gas, such as methylsilane, is only allowed to pass through when the first zone 110 moves under the second gas nozzle, while the second gas nozzle is controlled to pass through the low flow rate of the second gas when the first zone 110 moves to other positions. Both of the above-mentioned two adjustment methods can make the first ratio corresponding to the first zone 110 in the first stage smaller than the second ratio corresponding to the second zone 120.

[0126] In some other cases, in the first stage, not only the first reaction gas and the second reaction gas with fixed flow rates are simultaneously passed through the first zone 110 and the second zone 120 by using the first passing-in device, but also the first reaction gas or the second reaction gas is passed through by using the second passing-in device containing multiple gas nozzles with smaller sizes, so as to locally supplement the first reaction gas or the second reaction gas with higher flow rates.

[0127] In some examples, the second passing-in gas can be designed to pass through the first reaction gas, such as ammonia, and the second passing-in device is located above the second zone 120, so as to locally supplement the first reaction gas with higher flow rates above the second zone 120 by using the second passing-in device, so that the first ratio corresponding to the first zone 110 in the first stage is smaller than the second ratio corresponding to the second zone 120.

[0128] In some other examples, the second passing-in gas can be designed to pass through the second reaction gas, such as methylsilane, and the second passing-in device is located above the first zone 110, so as to locally supplement the second reaction gas with higher flow rates above the first zone 110 by using the second passing-in device, so that the first ratio corresponding to the first zone 110 in the first stage is smaller than the second ratio corresponding to the second zone 120.

[0129] It should be noted that in the above-mentioned three embodiments, i.e., the method of adjusting the pressure in the reaction chamber, the deposition temperature, or the flow rate ratio of the first reaction gas and the second reaction gas in the deposition process to form the passivation layer 102 with unique stress distribution, the three embodiments can exist alone, or two of them can exist together, or all of them can exist together, which can be selected according to actual needs.

[0130] In some other embodiments, in combination with the above-mentioned three embodiments, the first reaction gas and the second reaction gas can be designed to pass through the first zone 110 and the second zone 120 by using the first passing-in device, and the first reaction gas or the second reaction gas can be designed to pass through by using the second passing-in device containing multiple gas nozzles with smaller sizes, so as to locally supplement the first reaction gas or the second reaction gas with higher flow rates. 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.

[0131] 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.

[0132] 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.

[0133] In some cases, the deposition temperature of the second region 120 can be 200-400°C, and the deposition temperature of the first region 110 is 25-40°C lower than the deposition temperature of the second region 120, at least in the second stage. It is worth noting that the adjustment range of the deposition temperature of the first region 110 and the second region 120 is low, which is conducive to making the change of the pressure in the reaction chamber have a greater impact on the internal stress in the formed passivation layer 102, so as to ensure that the passivation layer 102 with a unique stress distribution is formed.

[0134] In some examples, on the basis that the pressure in the reaction chamber is gradually increased in the control first stage and the pressure in the reaction chamber is a fixed value in the second stage, the deposition temperature of the second region 120 can be 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C or 400°C, etc., at least in the second stage.

[0135] In some examples, on the basis that the pressure in the reaction chamber is gradually increased in the control first stage and the pressure in the reaction chamber is a fixed value in the second stage, the difference between the deposition temperature of the first region 110 and the deposition temperature of the second region 120 can be 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, etc., at least in the second stage.

[0136] In some cases, in addition to controlling the deposition temperature of the first region 110 to be lower than the deposition temperature of the second region 120 in the second stage, the deposition temperature of the first region 110 can also be controlled to be lower than the deposition temperature of the second region 120 in the first stage.

[0137] In still other embodiments, in combination with reference to Figure 3 and Figure 7 The step of forming the passivation layer 102 can include: placing the initial battery piece 100 after the slotting treatment in the reaction chamber; and forming the passivation layer 102 on the first region 110 and the second region 120 by using a deposition process, the deposition process including a first stage and a second stage connected in sequence, the pressure in the reaction chamber is gradually increased in the control first stage, the pressure in the reaction chamber is a fixed value in the second stage, and 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.

[0138] On the basis, in the process of the deposition process, the first reaction gas and the 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 region 110 is a third ratio, the ratio of the flow rates of the first reaction gas and the second reaction gas introduced into the second region 120 is a fourth ratio, and the third ratio is greater than the fourth ratio.

[0139] In some cases, the first reaction gas can be a nitrogen source gas, and the second reaction gas can be a silicon source gas; the third ratio is greater than the fourth ratio, that is, the nitrogen-to-silicon ratio corresponding to the first region 110 is greater than the nitrogen-to-silicon ratio corresponding to the second region 120, which can promote the formation of more hydrogen bonds in the first part 112, thereby further improving the hydrogen passivation effect of the passivation layer 102 as a whole. Based on this, on the basis of gradually increasing the pressure in the reaction chamber in the first stage and the pressure in the reaction chamber being a fixed value in the second stage, at least in the second stage, the nitrogen-to-silicon ratio corresponding to the first region 110 is controlled to be greater than the nitrogen-to-silicon ratio corresponding to the second region 120, which is beneficial to the synergistic effect of the adjustment of the pressure in the reaction chamber and the adjustment of the nitrogen-to-silicon ratio, so that the passivation layer 102 as a whole reaches a moderate density and has a good passivation effect on the basis of forming a unique stress distribution.

[0140] In some cases, in addition to controlling the third ratio corresponding to the first region 110 to be greater than the fourth ratio corresponding to the second region 120 in the second stage, the flow rate ratio of the first reaction gas and the second reaction gas introduced into the first region 110 in the first stage can be further controlled to be a third ratio, and the flow rate ratio of the first reaction gas and the second reaction gas introduced into the second region 120 can be further controlled to be a fourth ratio, and the third ratio is greater than the fourth ratio.

[0141] In some cases, the deposition process is a plasma enhanced chemical vapor deposition process; at least in the second stage, the plasma power corresponding to the first region 110 is controlled to be lower than the plasma power corresponding to the second region 120. In this way, it is beneficial to further reduce the bombardment damage suffered by the finally formed first part 112, so as to further improve the film quality of the finally formed passivation layer 102.

[0142] In some cases, in addition to controlling the plasma power corresponding to the first region 110 to be lower than the plasma power corresponding to the second region 120 in the second stage, the plasma power corresponding to the first region 110 in the first stage can be further controlled to be lower than the plasma power corresponding to the second region 120.

[0143] In some cases, the ratio of the third ratio and the fourth ratio can be 110%~115%, for example, can be 110%, 111%, 112%, 113%, 114% or 115%, etc.; at least in the second stage, the ratio of the plasma power corresponding to the first region 110 and the plasma power corresponding to the second region 120 is 90%~92.5%, for example, can be 90%, 90.5%, 91%, 91.5%, 92% or 92.5%, etc. It is worth noting that the adjustment range of the ratio of the third ratio and the fourth ratio is low, and the adjustment range of the difference between the plasma power corresponding to the first region 110 and the plasma power corresponding to the second region 120 is low, which is beneficial to make the change of the pressure in the reaction chamber have a greater impact on the internal stress in the formed passivation layer 102, so as to ensure that the passivation layer 102 with unique stress distribution is formed.

[0144] In the various embodiments described above, with reference to Figure 7 , along the third direction Z, the thickness of the finally formed passivation layer 102 can be 75nm~85nm, for example, 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 piece 100.

[0145] In the various embodiments described above, after forming the groove 101, before forming the passivation layer 102, the method for manufacturing the photovoltaic cell can further include: forming a passivation film (not shown in the figure) by ALD process, and the material of the passivation film can be aluminum oxide.

[0146] In some examples, along the third direction Z, the thickness of the aluminum oxide can be 1nm~10nm, for example, can be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm or 10nm, etc.

[0147] In the various embodiments described above, with reference to Figure 8 , after the step S4 cutting treatment, the photovoltaic cell 103 includes a cutting edge 113, and the method for manufacturing the photovoltaic cell can further include: performing laser annealing treatment on the cutting edge 113 to further reduce the damage caused by the cutting treatment to the photovoltaic cell 103, thereby improving the photoelectric conversion efficiency of the photovoltaic cell 103; or, with reference to Figure 8 and Figure 10 , Figure 10A partial enlarged sectional view of the edge passivation layer after the step S4 is provided in the manufacturing method of the photovoltaic cell according to an embodiment of the present disclosure. After the step S4, the photovoltaic cell 103 includes a cutting edge 113. The manufacturing method of the photovoltaic cell can further include: forming the edge passivation layer 104 on the cutting edge 113, and passivating the cutting edge 113 formed by the cutting process, so as to further improve the photoelectric conversion efficiency of the photovoltaic cell 103.

[0148] In summary, after the step S2, the passivation layer 102 is formed on the surface of the initial cell piece 100 with the groove 101. In this way, not only the step S2, but also the step S3, can passivate the groove 101 formed by the grooving process by means of the passivation layer 102, and can guide the initial cell piece 100 to be separated at the groove 101 in the subsequent cutting process by means of the stress distribution characteristics of the passivation layer 102 at the groove 101. Therefore, the process parameters of the subsequent cutting process can be further reduced by means of the internal stress of the passivation layer 102, so as to further reduce the damage caused by the cutting process and improve the cutting efficiency of the cutting process.

[0149] Another embodiment of the present disclosure further provides a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided by the foregoing embodiments. The photovoltaic cell provided by another embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0150] Reference Figure 8 Or Figure 10 The photovoltaic cell 103 is formed according to the manufacturing method of the photovoltaic cell according to any one of the foregoing embodiments. In this way, the photoelectric conversion efficiency of the photovoltaic cell 103 can be improved.

[0151] Still another embodiment of the present disclosure further provides a photovoltaic module including a plurality of photovoltaic cells formed by the manufacturing method of the photovoltaic cell provided by the foregoing embodiments, or a plurality of photovoltaic cells provided by the foregoing embodiments. The photovoltaic module provided by still another embodiment of the present disclosure will be described below with reference to the accompanying drawings. It should be noted that the same or corresponding parts as those of the foregoing embodiments will not be described herein.

[0152] Reference Figures 1 to 12 The photovoltaic module includes: a cell string connected by a plurality of photovoltaic cells 103 formed by the manufacturing method of the photovoltaic cell provided by the foregoing embodiments, or connected by a plurality of photovoltaic cells 103 provided by the foregoing embodiments; an encapsulation adhesive film 41 for covering the surface of the cell string; and a cover plate 42 for covering the surface of the encapsulation adhesive film 41 away from the cell string.

[0153] wherein, Figure 11 a partial perspective view of a cell string in a photovoltaic module according to yet another embodiment of the disclosure; Figure 12 a partial cross-sectional view of a photovoltaic module according to yet another embodiment of the disclosure.

[0154] In some embodiments, the photovoltaic cell 103 comprises one or any combination of a PERC (Passivated Emitter Rear Cell) cell, an IBC (Interdigitated Back Contact) cell, a TOPCon (Tunnel Oxide Passivated Contact) cell, a HIT / HJT (Heterojunction Technology) cell, a solar thin film cell, or a stacked cell. The solar thin film cell comprises one or any combination of a perovskite solar thin film cell, a copper-indium-selenium solar thin film cell, a gallium-arsenide solar thin film cell, and a cadmium-sulfide solar thin film cell. The stacked cell comprises one or any combination of a perovskite cell stacked with a crystalline silicon cell, a perovskite cell stacked with a perovskite cell, and a perovskite cell stacked with a thin film cell.

[0155] In some embodiments, the photovoltaic cell 103 can be a single-crystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-element compound solar cell, which can be a cadmium-sulfide solar cell, a gallium-arsenide solar cell, a copper-indium-selenium solar cell, or a perovskite solar cell.

[0156] In some embodiments, the photovoltaic cells 103 are electrically connected in a whole piece or multiple pieces to form a plurality of cell strings, and the plurality of cell strings are electrically connected in series and / or in parallel. The photovoltaic cell 103 can be a whole piece cell or a sliced cell, which refers to a cell formed by cutting a whole piece cell.

[0157] In some embodiments, in combination with reference to Figure 11 and Figure 12 the plurality of photovoltaic cells 103 can be electrically connected by the conductive ribbon 43. Figure 11 and Figure 12Only the positional relationship between the photovoltaic cells 103 is shown, i.e., the photovoltaic cells 103 have the same arrangement direction of electrodes of the same polarity or each photovoltaic cell 103 has electrodes of the positive polarity arranged on the same side, so that the conductive strips 43 are connected to 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, i.e., the electrodes of adjacent photovoltaic cells are sequentially arranged in the order of the first polarity, the second polarity, and the first polarity, and then the conductive strips are connected to the same side of two adjacent photovoltaic cells.

[0158] In some embodiments, no spacing can be provided between adjacent photovoltaic cells, i.e., adjacent photovoltaic cells can overlap each other.

[0159] In some embodiments, the encapsulation film 41 includes a first encapsulation layer and a second encapsulation layer, the first encapsulation layer covers one of the front surface or the back surface of the photovoltaic cell 103, and the second encapsulation layer covers the other of the front surface or the back surface of the photovoltaic cell 103. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate (EVA) film, a polyolefin elastomer (POE) film, or a polyethylene terephthalate (PET) film, or at least one of the first encapsulation layer or the second encapsulation layer can also be an EP film, an EPE film, or a PVP film. The EP film refers to a co-extrusion film formed by stacking an EVA film and a POE film, the EPE film refers to a co-extrusion film formed by stacking an EVA film, a POE film, and an EVA film in sequence, and the PVP film refers to a co-extrusion film formed by stacking a POE film, an EVA film, and a POE film in sequence. The co-extrusion film can be prepared by extruding one or more raw materials onto another film that has been prepared or by bonding different types of films to each other during the film processing.

[0160] In some cases, the first encapsulation layer and the second encapsulation layer have a boundary before lamination, and after the lamination process, the photovoltaic module is formed without the concept of the first encapsulation layer and the second encapsulation layer, i.e., the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0161] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or a cover plate having a light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 can be a concave-convex surface or a suede surface containing a plurality of convex structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate opposite the first encapsulation layer and a second cover plate opposite the second encapsulation layer.

[0162] In some embodiments, the photovoltaic cell 103 can be a with- or without- busbar cell.

[0163] It should be understood by those of ordinary skill in the art that the above-mentioned embodiments are specific embodiments for realizing the present disclosure, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the embodiments of the present disclosure, and therefore the protection scope of the embodiments of the present disclosure should be subject to the scope defined by 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; wherein the passivation layer includes a first portion located in the first region and a second portion located in the second region, the internal stress in the first portion is higher than the internal stress in the second portion, and the internal stress in the first portion tends to decrease along the direction of the passivation layer away from the initial battery cell; The first part and the initial solar cell are cut to divide the single initial solar cell into at least two photovoltaic cells.

2. 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 picosecond laser with a laser power of 5W to 30W; or, the first part and the initial battery cell are cut using a cold cutting process.

3. The method for manufacturing a photovoltaic cell according to claim 1 or 2, characterized in that, After the passivation layer is formed, and before the cutting process is performed, the method further includes: pre-cutting the first portion and the initial battery cell to form a cutting slit in the portion of the first portion and the initial battery cell that is directly opposite the groove.

4. The method for manufacturing a photovoltaic cell according to claim 3, characterized in that, The initial solar cell includes a doped semiconductor layer closest to the passivation layer; in 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%; 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 slit is also formed in the remaining doped semiconductor layer, and the ratio of the cutting slit depth in the remaining doped semiconductor layer to the reference thickness is 30% to 60%.

5. 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; and / or, the defect density of the first part is higher than that of the second part; and / or, the number of nitrogen-hydrogen bonds in the first part is lower than that in the second part.

6. 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.

7. The method for manufacturing a photovoltaic cell according to claim 6, characterized in that, The pressure in the reaction chamber during the first stage is gradually increased from 20 Pa to 150 Pa, and the pressure in the reaction chamber during the second stage is 150 Pa.

8. 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.

9. The method for manufacturing a photovoltaic cell according to claim 8, characterized in that, The deposition temperature in the second zone is 200℃~400℃, and the deposition temperature in the first zone is 50℃~80℃ higher than that in the second zone.

10. 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. During the deposition process, a first reactive gas and a second reactive gas are introduced into the reaction chamber. The deposition process includes a first stage and a second stage connected in sequence. The ratio of the flow rates of the first reactive gas and the second reactive gas introduced into the first region in the first stage is controlled to be a first ratio value. The ratio of the flow rates of the first reactive gas and the second reactive gas introduced into the second region in the first stage is controlled to be a second ratio value. The ratio of the flow rates of the first reactive gas and the second reactive gas introduced into both the first region and the second region in the second stage is the second ratio value. Wherein, the first ratio is less than the second ratio.

11. The method for manufacturing a photovoltaic cell according to claim 10, characterized in that, The deposition process is plasma-enhanced chemical vapor deposition (PECVD). During the PECVD process, the plasma power corresponding to the first region in the first stage is controlled to be a first power, the plasma power corresponding to the second region in the first stage is controlled to be a second power, and the plasma power corresponding to both the first region and the second region in the second stage is the second power. Wherein, the first power is greater than the second power.

12. The method for manufacturing a photovoltaic cell according to claim 11, characterized in that, The flow rate of the second reactive gas introduced into the first zone is controlled to be equal to the flow rate of the second reactive gas introduced into the second zone, and the flow rate of the first reactive gas introduced into the first zone in the first stage is the first flow rate, and the flow rate of the first reactive gas introduced into the second zone in the first stage is the second flow rate, with the ratio of the first flow rate to the second flow rate being 70%-80%; the ratio of the first power to the second power is 115%-120%.

13. 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, the deposition process including a first stage and a second stage connected in sequence; wherein the duration of the first stage is 10 seconds to 60 seconds, and the duration of the second stage is 2 minutes to 5 minutes.

14. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that, After the cutting process, the photovoltaic cell includes a cut edge; the method for manufacturing the photovoltaic cell further includes: The cut edge is subjected to laser annealing; or, an edge passivation layer is formed on the cut edge.

15. 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; or, multiple grooves are located in the same first area, and multiple grooves located in the same first area are arranged in an array.

16. The method for manufacturing a photovoltaic cell according to claim 15, characterized in that, The orthographic projection of the groove onto the initial battery cell is a rectangle extending along a first direction, and the width of the rectangle is 20μm~50μm along a direction perpendicular to the first direction. Alternatively, the orthographic projection of the groove onto the initial battery cell is a wavy shape extending along a first direction, and the distance between two opposite edges of the wavy shape is 20μm~50μm along a direction perpendicular to the first direction; Alternatively, multiple groove arrays located in the same first region are arranged such that the distance between the two edges of the two furthest grooves along a direction perpendicular to the first direction is 20μm to 50μm.

17. 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 16.

18. 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 16, or by connecting multiple photovoltaic cells as described in claim 17; 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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