A photovoltaic cell and a photovoltaic module

Abstract

The embodiment of the present application provides a photovoltaic cell and a photovoltaic module. The photovoltaic cell comprises a silicon substrate, the silicon substrate comprises a first surface and a second surface arranged away along a first direction, and a side surface connecting the first surface and the second surface, the side surface comprises a cutting surface; wherein the cutting surface comprises a cutting edge adjacent to the first surface, a fracture edge adjacent to the second surface, and a corrugated area arranged between the cutting edge and the fracture edge, a surface of the corrugated area has a plurality of convex structures continuously distributed along the first direction, each of the convex structures extends along a second direction, and the first direction is perpendicular to the second direction; and a passivation layer is arranged on the cutting surface. In the embodiment of the present application, the convex structures formed on the cutting surface can not only provide more refraction surfaces for incident light and improve the light trapping effect of the cutting surface, but also provide a better deposition surface basis for the passivation process, which is beneficial to improving the passivation effect of the passivation layer.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic processing technology, specifically relating to a photovoltaic cell and a photovoltaic module. Background Technology

[0002] As a key component of photovoltaic modules, the manufacturing process of photovoltaic cells directly affects the performance and cost of solar cells. Multi-cell photovoltaic cells, as a common type of photovoltaic cell, have the advantages of low power loss, high output power, and high power generation.

[0003] Currently, laser cutting is commonly used to cut a single solar cell into multiple cells, which are then packaged into photovoltaic modules. However, during the laser cutting process, the cut surfaces are typically exposed silicon substrates. Compared to the original sides of the photovoltaic cell, these surfaces are irregular and uneven, resulting in relatively poor passivation and light-trapping performance. Therefore, improving the passivation and light-trapping effects on the cut surfaces is a pressing technical challenge. Summary of the Invention

[0004] This application aims to provide a photovoltaic cell and a photovoltaic module to solve the problem of poor passivation effect of the cut surface of existing photovoltaic cells.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, this application discloses a photovoltaic cell, the photovoltaic cell comprising: a silicon substrate; the silicon substrate including a first surface and a second surface disposed opposite to each other along a first direction, and a side surface connecting the first surface and the second surface, the side surface including a cut surface; wherein,

[0007] The cutting surface includes: a cutting edge adjacent to the first surface, a fracture edge adjacent to the second surface, and a corrugated area disposed between the cutting edge and the fracture edge. The surface of the corrugated area has a plurality of protrusions continuously distributed along a first direction, each of the protrusions extending along a second direction, wherein the first direction is perpendicular to the second direction.

[0008] A passivation layer is provided on the cut surface.

[0009] Optionally, the protrusion structure is triangular, semi-circular, or trapezoidal.

[0010] Optionally, along the second direction, the length of the corrugated region accounts for 1% to 90% of the total length of the cut surface;

[0011] Along the first direction, the width of the corrugated area accounts for 5% to 80% of the total width of the cut surface.

[0012] Optionally, along the second direction, the length of the corrugated area is 5 mm to 160 mm;

[0013] Along the first direction, the width of the corrugated region is 10 micrometers to 120 micrometers.

[0014] Optionally, in the first direction, the density of the protrusion structure is 1 to 5 per 1 μm.

[0015] Optionally, the cutting surface includes a first edge region along the first direction near the cutting edge, a second edge region near the break edge, and an intermediate region located between the first edge region and the second edge region; wherein,

[0016] The corrugated area is located in the middle region.

[0017] Optionally, there may be multiple corrugated areas, and the multiple corrugated areas may be arranged non-aligned at their top ends along the first direction.

[0018] Optionally, the width of the protrusion structure is W, which satisfies: 0.4 micrometers ≤ W ≤ 3 micrometers.

[0019] Optionally, the height of the protrusion structure is H, which satisfies: 0.05 micrometers ≤ H ≤ 1 micrometer.

[0020] Optionally, the surface of the corrugated region is a third surface, and the surface of the passivation layer away from the silicon substrate is a fourth surface; the height of each position of the fourth surface increases with the increase of the height of the corresponding position of the third surface, and the height of each position of the fourth surface decreases with the decrease of the height of the corresponding position of the third surface.

[0021] The height refers to the distance from the third or fourth surface to the surface of the cut surface.

[0022] Optionally, the passivation layer has a first thickness in the corrugated region, which ranges from 45 nanometers to 75 nanometers.

[0023] Optionally, the area outside the corrugated area on the cut surface is a non-corrugated area, the thickness of the passivation layer in the corrugated area is a first thickness, the thickness of the passivation layer in the non-corrugated area is a second thickness, and the first thickness is less than the second thickness.

[0024] Optionally, the difference between the first thickness and the second thickness is 5 nanometers to 10 nanometers.

[0025] Optionally, the cut surface further includes a crack structure, wherein the extension direction of the crack structure and the extension direction of the protrusion structure form an angle.

[0026] Secondly, this application also discloses a photovoltaic module, the photovoltaic module comprising: a plurality of battery strings, the battery strings comprising a plurality of photovoltaic cells and interconnects as described in any one of the above claims;

[0027] The photovoltaic cells are electrically connected to the interconnecting components.

[0028] In this embodiment, the side surface of the silicon substrate of the photovoltaic cell may include a cut surface, which can be formed during the process of cutting a full cell into half cells. A corrugated region exists between the cut edge and the break edge of the cut surface. The surface of the corrugated region has multiple continuously distributed protrusions along a first direction, and each protrusion extends along a second direction. The protrusions formed on the cut surface not only provide more refractive surfaces for incident light, improving the light-trapping effect of the cut surface, but also, because the protrusions are continuously distributed and extend in the second direction, they are smoother and more even than randomly distributed textured structures. Therefore, the corrugated region provides a better deposition surface for the passivation process, which is beneficial to improving the passivation effect of the passivation layer.

[0029] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0031] Figure 1 This is a schematic diagram of the structure of a photovoltaic cell according to an embodiment of this application;

[0032] Figure 2 yes Figure 1 One of the schematic diagrams of the cross-sectional structure of a photovoltaic cell (before the passivation layer is applied);

[0033] Figure 3 yes Figure 1 The second schematic diagram of the cross-sectional structure of a photovoltaic cell (after the passivation layer is applied);

[0034] Figure 4 This is a schematic diagram of another photovoltaic cell structure described in an embodiment of this application;

[0035] Figure 5 This is a schematic diagram of another type of photovoltaic cell described in the embodiments of this application;

[0036] Figure 6This is an enlarged structural schematic diagram of a protrusion structure described in an embodiment of this application;

[0037] Reference numerals: 10-cut surface, 100-corrugated area, 101-cut edge, 102-fracture edge, 103-protruding structure, 104-passivation layer, 105-first edge region, 106-second edge region, 107-middle region, 108-non-corrugated area, 11-first surface, 12-second surface, x-first direction, y-second direction. Detailed Implementation

[0038] Embodiments of the present invention will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0039] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0040] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] This application provides a photovoltaic cell, which can be formed using a cutting process. The photovoltaic cell can be a half-cell or a multi-cell cell. This application only uses a half-cell photovoltaic cell as an example for illustration; other types of photovoltaic cells can be described by analogy. Specifically, when the photovoltaic cell is a half-cell, it can be cut from a full-cell cell. Therefore, one side surface of the photovoltaic cell is a cutting surface, which is formed during the process of cutting the full-cell cell into a half-cell cell.

[0043] Reference Figure 1 The diagram shows a structural schematic of a photovoltaic cell according to an embodiment of this application. Figure 2 , showed Figure 1 One of the schematic diagrams of the cross-sectional structure of a photovoltaic cell (before the passivation layer is applied) is shown below. Figure 3 , showed Figure 1 The second schematic diagram shows the cross-sectional structure of a photovoltaic cell (after the passivation layer is applied).

[0044] like Figures 1 to 3 As shown, the photovoltaic cell may specifically include: a silicon substrate, the silicon substrate including a first surface 11 and a second surface 12 disposed opposite to each other along a first direction x, and a side surface connecting the first surface 11 and the second surface 12, the side surface including a cut surface 10; wherein, the cut surface 10 may include: a cut edge 101 adjacent to the first surface 11, a fracture edge 102 adjacent to the second surface 12, and a corrugated region 100 disposed between the cut edge 101 and the fracture edge 102, the surface of the corrugated region 100 having a plurality of protrusions 103 continuously distributed along the first direction x, each protrusion 103 extending along the second direction y, the first direction x being perpendicular to the second direction y; a passivation layer 104 is disposed on the cut surface 10.

[0045] In this embodiment, the side surface of the photovoltaic cell may include a cutting surface 10, which may be formed during the process of cutting a full cell into half cells. A corrugated region 100 is present between the cutting edge 101 and the break edge 102 of the cutting surface 10. The surface of the corrugated region 100 has a plurality of protrusions 103 continuously distributed along a first direction x, and each protrusion 103 extends along a second direction y.

[0046] A continuous distribution of raised structures 103 is formed on the cut surface 10. Compared with spaced raised structures or groove structures, this provides more refractive surfaces for incident light in a limited area, improving the light-trapping effect of the cut surface 10. Moreover, since the raised structures 103 are continuously distributed and extend in the second direction y, they are flatter and smoother than randomly distributed texture structures. Therefore, the corrugated area 100 can provide a better deposition surface for the passivation process, which is beneficial to improving the passivation effect of the passivation layer 104.

[0047] Furthermore, the improved light trapping effect and passivation performance on the cut surface can reduce the performance gap between the cut surface and the original side surface to a certain extent, improve the consistency of side surface performance on the same cell, and prevent current loss caused by excessive composite at the cut edge, which would ultimately limit the improvement of battery efficiency.

[0048] Specifically, the first surface 11 of the photovoltaic cell can be either the front or the back, and the second surface 12 can be either the front or the back; this embodiment does not limit this. The cutting surface 10 between the first surface 11 and the second surface 12 can be formed during the process of cutting a full cell into half cells.

[0049] In practical applications, during the process of cutting the full-size solar cell into half-size solar cells, a laser can be used to cut a notch approximately 5 mm long at the edge of the first surface 11 of the full-size solar cell. Then, laser heating is applied along the notch to form a cutting line on the first surface 11. Subsequently, cold water is sprayed onto the first surface 11 of the full-size solar cell. Due to rapid cooling, the full-size solar cell will crack along the cutting line. In this way, the full-size solar cell can be divided into two half-size solar cells (i.e., the photovoltaic solar cell described in this application embodiment). Furthermore, in the photovoltaic solar cell, the side surface formed by the laser cutting and cracking method is the cutting surface 10, and within the cutting surface 10, the edge formed by laser cutting and close to the first surface 11 is the cutting edge 101, and the edge formed by silicon wafer cracking and close to the second surface 12 is the fracture edge 102.

[0050] like Figure 1 As shown, on the cut surface 10 of the photovoltaic cell described in this embodiment, there is a corrugated area 100 between the cut edge 101 and the break edge 102. Figure 2 As shown, the corrugated region 100 is provided with a plurality of protrusions 103 continuously distributed along the first direction x, and each protrusion 103 extends along the second direction y. Compared with the randomly distributed texture structure, it is flatter and smoother. Therefore, the corrugated region 100 can provide a better deposition surface basis for the passivation process, which is beneficial to improving the passivation effect of the passivation layer 104.

[0051] In specific applications, by controlling the process parameters such as the laser action time, speed, and laser energy during laser grooving and laser cutting to form the cutting line, and / or by controlling the process parameters such as the action of cold water and the time, speed, or magnitude of the force during cold water spraying and breaking, the texture of the corrugated area 100 can be controlled. By reasonably combining the above process parameters, the micromorphology of the corrugated area 100 can be controlled to form the above-mentioned protrusion structure 103 in the corrugated area 100.

[0052] In practical applications, the protruding structure 103 can also provide more refracting surfaces for incident light, increase the light trapping effect of the cut surface 10, thereby improving the light absorption efficiency of the photovoltaic cell.

[0053] In some optional embodiments of this application, the protrusion structure 103 may be triangular, semi-circular, or trapezoidal, that is, the cross-sectional shape of the protrusion structure 103 may be triangular, semi-circular, or trapezoidal, etc. The embodiments of this application do not specifically limit the cross-sectional shape of the protrusion structure 103.

[0054] In practical applications, when the cross-sectional shape of the protrusion structure 103 is triangular, semi-circular, or trapezoidal, the protrusion structure 103 is relatively easy to form on the cutting surface 10, and the processing is simple. For example, during the cutting process, the protrusion structure 103 can be formed by fracture along a certain crystal orientation. Moreover, the protrusion structure 103 can provide more refractive surfaces for incident light, and the light-trapping effect of the photovoltaic cell is correspondingly better.

[0055] It should be noted that the accompanying drawings of this application only show the case where the cross-section of the protruding structure 103 is triangular. The case where the cross-section of the protruding structure 103 is semi-circular or trapezoidal can be referred to accordingly.

[0056] In some optional embodiments of this application, along the second direction y, the length of the corrugated region 100 accounts for 1% to 90% of the total length of the cut surface 10, and along the first direction x, the width of the corrugated region 100 accounts for 5% to 80% of the total width of the cut surface 10. That is, it is not necessary for the corrugated region 100 to penetrate the cut surface 10 along the second direction y, and it is not necessary for the corrugated region 100 to penetrate the cut surface 10 along the first direction x. In this way, the corrugated region 100 can be more easily processed and formed, and the quality of the protrusion structure 103 of the corrugated region 100 is easier to control.

[0057] In practical applications, the larger the proportion of the length of the corrugated area 100 to the total length of the cut surface 10, and the larger the proportion of the width of the corrugated area 100 to the total width of the cut surface 10, the more difficult it is to form the protruding structure 103 on the corrugated area 100, and the more difficult it is to control the processing quality. Simultaneously, the larger the proportion of the length of the corrugated area 100 to the total length of the cut surface 10, and the larger the proportion of the width of the corrugated area 100 to the total width of the cut surface 10, the better the overall smoothness and flatness of the cut surface 10, and the better the passivation effect of the passivation layer 104 formed on the cut surface 10. Therefore, in practical applications, it is necessary to control the length and width proportions of the corrugated area 100 within a reasonable range to balance the difficulty and quality of forming the protruding structure 103, as well as the overall smoothness and flatness of the cut surface 10.

[0058] For example, to achieve better overall smoothness and flatness of the cut surface 10, the length and width proportions of the corrugated area 100 on the cut surface 10 can be 90% and 80%, respectively. Alternatively, if the machinability of the corrugated area 100 is a primary consideration, the length and width proportions of the corrugated area 100 on the cut surface 10 can be 50% and 40%, respectively. This application does not specifically limit the length and width proportions of the corrugated area 100 on the cut surface 10 in this embodiment.

[0059] Optionally, since the length of the cut surface 10 of the photovoltaic cell along the second direction y is usually between 160 mm and 180 mm, in order to control the length of the corrugated area 100 along the second direction y to be between 1% and 90% of the length of the cut surface 10, while taking into account the machinability and overall smoothness of the corrugated area 100, the length of the corrugated area 100 along the second direction y can be between 5 mm and 160 mm.

[0060] Similarly, since the width of the cut surface 10 of the photovoltaic cell along the first direction x is usually between 160 micrometers and 180 micrometers, in order to control the proportion of the width of the corrugated area 100 along the first direction x to the width of the cut surface 10 to between 5% and 80%, while taking into account the machinability and overall smoothness of the corrugated area 100, the width of the corrugated area 100 along the first direction x is 10 micrometers to 120 micrometers.

[0061] For example, the length of the corrugated area 100 along the second direction y can be 5 mm, 30 mm, 55 mm, 120 mm or 160 mm, etc., and the width of the corrugated area 100 along the first direction x can be 10 micrometers, 40 micrometers, 55 micrometers, 82 micrometers or 120 micrometers, etc. In this embodiment of the application, the length of the corrugated area 100 along the second direction y and the width along the first direction x are not specifically limited.

[0062] In some optional embodiments of this application, the density of the protrusion structure 103 in the first direction x is 1 to 5 per 1 μm, so as to control the density of the protrusion structure 103 within a reasonable range, improve the processability and overall smoothness, and improve the quality of the passivation layer 104 attached to the protrusion structure 103.

[0063] like Figure 2 As shown, the cutting surface 10 may specifically include a first edge region 105 along the first direction x near the cutting edge 101, a second edge region 106 near the fracture edge 102, and an intermediate region 107 located between the first edge region 105 and the second edge region 106. A corrugated region 100 is disposed in the intermediate region 107 so that the protruding structure 103 of the corrugated region 100 maintains a reasonable gap with both the cutting edge 101 and the fracture edge 102. This ensures that the protruding structure 103 of the corrugated region 100 is not affected by the laser from the cutting edge 101, nor by the fracture stress of the fracture edge 102, resulting in good structural integrity. Simultaneously, since the intermediate region 107 experiences the greatest stress, and the corrugated region 100, due to the relatively regular shape of its protruding structure 103, can withstand greater stress without deformation or other defects, by placing the corrugated region 100 in the intermediate region 107, the protruding structure 103 of the corrugated region 100 can also withstand greater stress, thereby maintaining the structural integrity of the cutting surface 10.

[0064] In some optional embodiments of this application, the corrugated area may be located in the middle of the central region, or slightly above or below it. The random distribution of the corrugated area helps to disperse the stress generated during the formation of the cutting surface, ensuring the structural integrity of the cutting surface 10.

[0065] Reference Figure 4 This shows a schematic diagram of another photovoltaic cell structure according to an embodiment of this application, with reference to... Figure 5 This illustration shows a structural schematic diagram of another photovoltaic cell according to an embodiment of this application. Figure 4 and Figure 5 As shown, there are multiple corrugated regions 100, and the top edges of these corrugated regions 100 are not aligned along the first direction x. This allows for flexible arrangement of the corrugated regions 100 on the cutting surface 10, reducing the difficulty of forming them. Furthermore, by positioning the top edges of the multiple corrugated regions 100 at different heights along the first direction x, it also allows the corrugated regions 100 to provide more refracting surfaces for incident light at different heights on the cutting surface 10, improving the light-trapping effect of the cutting surface 10.

[0066] In some optional embodiments of this application, the angle between the cut surface and the first surface is an acute angle, and the angle between the cut surface and the second surface is an obtuse angle, or the angle between the cut surface and the first surface is an obtuse angle, and the angle between the cut surface and the second surface is an acute angle. That is, the cut surface of the photovoltaic cell is an inclined plane. Compared with a vertical plane, the inclined plane has a larger surface area, and the distribution of multiple corrugated areas 100 at different positions on the cut surface can disperse the stress generated during the formation of the cut surface to a large extent, and can improve the light trapping performance by utilizing different positions on the cut surface.

[0067] It should be noted that the tops of the multiple corrugated areas on the cut surface 10 along the first direction x can be as follows: Figure 4 As shown, the settings can be decreased sequentially according to a certain pattern, or as follows: Figure 5 As shown, the arrangement is staggered, but this application embodiment does not impose specific limitations on it.

[0068] Reference Figure 6 The diagram shows an enlarged schematic of a protrusion structure according to an embodiment of this application, as shown below. Figure 6 As shown, the width of the protrusion structure 103 is W, which satisfies: 0.4 micrometers ≤ W ≤ 3 micrometers. By controlling the width of the protrusion structure 103 within a reasonable range, the protrusion structure 103 can have a certain light-trapping area and a low degree of undulation, which is conducive to depositing a passivation layer 104 on the cut surface 10 with the protrusion structure 103, and the passivation effect of the passivation layer 104 is good.

[0069] For example, the width W of the protrusion structure 103 can be 0.4 micrometers, 0.8 micrometers, 1.2 micrometers, 2.5 micrometers or 3 micrometers, etc. In this embodiment of the application, the width W of the protrusion structure 103 is not specifically limited.

[0070] like Figure 4 As shown, the height of the protrusion structure 103 is H, satisfying: 0.05 μm ≤ H ≤ 1 μm. This further reduces the surface roughness of the cut surface 10 and increases the passivation performance of the passivation layer 104 on the cut surface 10. During the deposition of the passivation layer 104, the smaller roughness of the protrusion structure 103 can reduce the increased surface area due to surface unevenness, ensuring the coating thickness of the passivation layer 104.

[0071] For example, the height H of the protrusion structure 103 can be 0.05 micrometers, 0.2 micrometers, 0.35 micrometers, 0.7 micrometers or 1 micrometer, etc. The embodiments of this application do not specifically limit the height H of the protrusion structure 103.

[0072] Optionally, the surface of the corrugated region 100 is a third surface, and the surface of the passivation layer 104 away from the silicon substrate is a fourth surface; the height of each position on the fourth surface increases with the increase of the height of the corresponding position on the third surface, and decreases with the decrease of the height of the corresponding position on the third surface; the height refers to the distance from the third or fourth surface to the surface of the cut surface 10, so that the morphology of the passivation layer 104 matches the surface morphology of the corrugated region 100. Figure 3 As shown, when the third surface of the protrusion structure 103 in the corrugated region 100 is serrated, the fourth surface of the passivation layer 104 can be serrated accordingly.

[0073] In practical applications, the regularly undulating sides of the protruding structure 103 provide a relatively smooth surface for the passivation layer 104. Controlling the growth of the passivation layer 104 onto the surface of the protruding structure 103 during deposition allows for better utilization of the protruding structure 103 to generate the passivation layer 104. This increases the area of ​​the passivation layer without increasing its thickness, thus meeting the passivation performance requirements. Furthermore, compared to filling the protruding structure 103 with the passivation layer 104 during deposition, the corrugated structure allows for better light trapping and reduces production costs.

[0074] In practical applications, due to the relatively regular undulating structure provided by the protrusion structure 103, when the passivation layer 104 is formed on the surface of the protrusion structure 103, it can provide good passivation performance and take into account the process time and cost of coating.

[0075] like Figure 3 As shown, the area outside the corrugated area 100 on the cut surface 10 is the non-corrugated area 108, and the thickness of the passivation layer 104 in the corrugated area 100 is the first thickness, which ranges from 45 nanometers to 75 nanometers.

[0076] The side of the protrusion 103 in the corrugated region 100 has a relatively smooth surface, so a thickness range of 45 nanometers to 75 nanometers in the corrugated region is sufficient to meet the passivation requirements of the corrugated region.

[0077] like Figure 3 As shown, the area outside the corrugated area 100 on the cut surface 10 is the non-corrugated area 108. The thickness of the passivation layer 104 in the corrugated area 100 is the first thickness, and the thickness of the passivation layer 104 in the non-corrugated area 108 is the second thickness. The first thickness is less than the second thickness.

[0078] Typically, the passivation layer 104 can be formed using a deposition process. For the same deposition thickness, the larger the surface area, the smaller the thickness of the passivation layer 104. Specifically, on the cut surface 10 described in this embodiment, the corrugated region 100 has a relatively regular surface undulation with a larger surface area, while the non-corrugated region 108 has a relatively smaller surface area. Therefore, when the first thickness of the passivation layer 104 in the corrugated region 100 is less than the second thickness of the passivation layer 104 in the non-corrugated region 108, the same deposition thickness can be used to form passivation layers 104 of different thicknesses in the corrugated region 100 and the non-corrugated region 108, simplifying the processing method.

[0079] For example, when the passivation layer 104 has a deposition thickness of 80 nanometers, since the surface area of ​​the corrugated region 100 is larger and the surface area of ​​the non-corrugated region 108 is relatively smaller, after deposition is completed, the thickness of the passivation layer 104 formed in the non-corrugated region 108 is usually close to 80 nanometers, while the thickness of the passivation layer 104 formed in the corrugated region 100 is usually less than 80 nanometers.

[0080] Optionally, the difference between the first thickness and the second thickness is 5 nanometers to 10 nanometers. This ensures that the passivation layer 104 formed in both the corrugated region 100 and the non-corrugated region 108 has a good passivation effect. At the same time, the passivation layer 104 in both the corrugated region 100 and the non-corrugated region 108 can be formed simultaneously through a single deposition of the same thickness, thus taking into account processability.

[0081] In some alternative embodiments of this application, the second thickness of the passivation layer 104 formed in the non-corrugated region 108 is typically 70-90 nanometers.

[0082] In some optional embodiments of this application, the cut surface 10 also includes a crack structure, which is generated during the formation of the cut surface and is difficult to avoid due to stress issues. The depth of the crack structure is greater than 1 micrometer, and the deep undulations are not conducive to the deposition of the passivation layer. Therefore, it is necessary to simultaneously provide the crack structure and the raised structure 103 of the ripple area on the cut surface to reduce the undulations on the cut surface caused by the deep crack structure and improve the coating quality of the subsequent passivation layer.

[0083] In some optional embodiments of this application, the cut surface 10 further includes a crack structure, the extension direction of which forms an angle with the extension direction of the protrusion structure 103. That is, compared with the relatively regular shape of the protrusion structure 103, the crack structure can be a diagonal or molten texture structure. An angle A is formed between the extension direction of the crack structure and the extension direction of the protrusion structure 103. The presence of angle A can guide a more uniform distribution of crack depth and width. Angle A is preferably greater than or equal to 45° and less than 90°. For example, angle A can be 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or 89°, etc.

[0084] In some alternative embodiments of this application, the crack structure extends from the first edge region to the second edge region, and the continuous crack structure is more conducive to controlling the morphology of the cut surface.

[0085] On the surface where the cracked area and the protruding structure 103 are located, there is no significant height difference between the two structures in the overall width direction of the cut surface.

[0086] In summary, the photovoltaic cells described in the embodiments of this application have at least the following advantages:

[0087] In this embodiment, the side surface of the silicon substrate of the photovoltaic cell may include a cut surface, which can be formed during the process of cutting a full cell into half cells. A corrugated region exists between the cut edge and the break edge of the cut surface. The surface of the corrugated region has multiple continuously distributed protrusions along a first direction, and each protrusion extends along a second direction. The protrusions formed on the cut surface not only provide more refractive surfaces for incident light, improving the light-trapping effect of the cut surface, but also, because the protrusions are continuously distributed and extend in the second direction, they are smoother and more even than randomly distributed textured structures. Therefore, the corrugated region provides a better deposition surface for the passivation process, which is beneficial to improving the passivation effect of the passivation layer.

[0088] This application also provides a photovoltaic module, which specifically includes: multiple cell strings, each cell string comprising multiple photovoltaic cells as described in any of the above embodiments and multiple interconnecting components; the photovoltaic cells and the interconnecting components are electrically connected. Specifically, the interconnecting components can be conductive parts such as photovoltaic solder ribbons.

[0089] The improved consistency of light trapping and passivation effects on different sides of photovoltaic cells has two advantages. First, when connecting modules in series, it is not necessary to distinguish between the cut edges and the original sides, reducing the difficulty of module arrangement. Second, it reduces the probability of photovoltaic cell efficiency reduction due to premature degradation on the cut surfaces, thereby improving the reliability and lifespan of the modules.

[0090] It should be noted that in the embodiments of this application, the structure of the photovoltaic cell in the photovoltaic module is the same as that of the photovoltaic cell described in any of the above embodiments, and its beneficial effects are similar, so it is not limited here.

[0091] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0092] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A photovoltaic cell, characterized by, The photovoltaic cell piece comprises a silicon substrate; The silicon substrate comprises a first surface and a second surface arranged away along a first direction, and a side surface connecting the first surface and the second surface, the side surface comprising a cutting surface; wherein, The cutting surface comprises a cutting edge adjacent to the first surface, a fracture edge adjacent to the second surface, and a corrugated region arranged between the cutting edge and the fracture edge, a surface of the corrugated region having a plurality of convex structures continuously distributed along the first direction, each of the convex structures extending along a second direction, the first direction being perpendicular to the second direction; A passivation layer is arranged on the cutting surface; The surface of the corrugated region is a third surface, and a side surface of the passivation layer away from the silicon substrate is a fourth surface; a height of each position of the fourth surface increases with an increase of a height of a corresponding position of the third surface, and a height of each position of the fourth surface decreases with a decrease of the corresponding position of the third surface; The height refers to a distance from the third surface or the fourth surface to a surface of the cutting surface; Along the second direction, a length of the corrugated region is 5 mm-160 mm.

2. The photovoltaic cell of claim 1, wherein, The convex structure is in a triangular structure, a semicircular structure, or a trapezoidal structure.

3. The photovoltaic cell of claim 1, wherein, Along the second direction, a length of the corrugated region accounts for 1%-90% in a total length of the cutting surface; Along the first direction, a width of the corrugated region accounts for 5%-80% in a total width of the cutting surface.

4. The photovoltaic cell of claim 3, wherein, Along the first direction, the width of the corrugated region is 10 microns-120 microns.

5. The photovoltaic cell of claim 1, wherein, In the first direction, a density of the convex structure is 1 / 1 micrometer-5 / 1 micrometer.

6. The photovoltaic cell of claim 1, wherein, The cutting surface comprises a first edge region close to the cutting edge along the first direction, a second edge region close to the fracture edge, and an intermediate region between the first edge region and the second edge region; wherein, The corrugated region is arranged in the intermediate region.

7. The photovoltaic cell of claim 6, wherein, The number of the corrugated regions is a plurality, and the plurality of corrugated regions are arranged in a non-aligned manner at top ends along the first direction.

8. The photovoltaic cell of claim 1, wherein, The width W of the convex structure satisfies: 0.4 microns≤W≤3 microns.

9. The photovoltaic cell of claim 1, wherein, The height H of the convex structure satisfies: 0.05 microns≤H≤1 microns.

10. The photovoltaic cell of claim 1, wherein, The thickness of the passivation layer in the corrugated region is a first thickness, and the first thickness ranges from 45 nanometers to 75 nanometers.

11. The photovoltaic cell of claim 10, wherein, An area of the cutting surface other than the corrugated region is a non-corrugated region, the thickness of the passivation layer in the corrugated region is a first thickness, the thickness of the passivation layer in the non-corrugated region is a second thickness, and the first thickness is less than the second thickness.

12. The photovoltaic cell of claim 11, wherein, The difference between the first thickness and the second thickness is 5 nanometers-10 nanometers.

13. The photovoltaic cell of claim 1, wherein, The cutting surface further comprises a crack structure, and an extension direction of the crack structure and an extension direction of the convex structure form an included angle.

14. A photovoltaic module, characterized by The photovoltaic assembly comprises a plurality of cell strings; The cell string comprises a plurality of photovoltaic cell pieces according to any one of claims 1-13 and a plurality of interconnectors; The photovoltaic cell pieces are electrically connected through the interconnectors.

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