Solar cell and photovoltaic module

Abstract

The utility model provides a solar cell and a photovoltaic assembly, the solar cell is provided with at least one first side surface and a second side surface adjacent to the first side surface, the first side surface is in lap joint with a welding strip, and the second side surface is a near light surface; a plurality of first sunken parts are distributed on the first side surface, a plurality of second sunken parts are distributed on the second side surface, and the first sunken parts and the second sunken parts are independently sunken towards the interior of the solar cell; and the ratio of the area ratio of the plurality of first concave parts distributed in the first side surface to the area ratio of the plurality of second concave parts distributed in the second side surface is (1.5-7.5): 1. According to the utility model, the tower footing-shaped structures with different shapes and sizes are introduced into the side wall surface of the solar cell, so that the cell is ensured to have high light absorption capacity and good passivation effect.

Description

TECHNICAL FIELD

[0001] The utility model belongs to solar cell field relates to a solar cell piece and photovoltaic module. BACKGROUND

[0002] Solar cell adopts semiconductor material, through the photon energy of incident light absorption, makes semiconductor electron - hole pair, establishes electric field in PN junction, makes electron and hole forcibly separate, makes carrier directional movement, is collected by metal electrode and produces voltage, and then realizes photoelectric conversion. The incident light reaches the front area of cell piece and is absorbed to produce electric current, and the side area of cell piece refracts the incident light and enhances the absorption of light. Therefore, the surface structure of cell piece plays a key role in the light absorption capacity of cell piece.

[0003] In the packaging of photovoltaic module, usually after printing metal grid line on the surface of cell piece, laying welding strip carries out laser welding, completes the precise electrical and structural interconnection, realizes current collection and circuit series connection. This forms part of the cell piece surface shielding, thereby reducing the use area of cell surface, and the cell piece also reflects part of the incident light, so that it cannot pass through the cell piece, causing the conversion efficiency of cell piece to be reduced. During the lapping of cell piece and welding strip, due to the defects of cell piece surface structure, edge leakage is also prone to occur, which can significantly reduce the voltage and conversion efficiency of the cell, and the cell piece needs to be insulated to prevent current from flowing out.

[0004] Therefore, how to accurately control the surface structure of solar cell piece to avoid the risk of battery leakage while ensuring the light absorption rate is a technical problem to be solved. Utility model content

[0005] In view of the deficiency of prior art, the utility model aims at providing a solar cell piece and photovoltaic module, introducing tower base structure with different shapes and sizes on the side wall surface of solar cell piece, forming rough surface, ensuring high light absorption and good passivation effect.

[0006] In order to achieve this purpose, the utility model adopts the following technical scheme:

[0007] The utility model provides a kind of solar cell piece, and the solar cell piece has at least one first side face, and the second side face being adjacent to the first side face is arranged, the first side face is overlapped with solder strip, and the second side face is near light surface;The first side face is distributed with several first recess, and the second side face is distributed with several second recess, and the first recess and the second recess independently recess towards the inside of the solar cell piece;The area ratio of the proportion of the area ratio of the several first recess distributed in the first side face and the several second recess distributed in the second side face is (1.5~7.5):1.

[0008] The ratio can be 1.5:1, 1.6:1, 2.0:1, 2.5:1, 3.0:1, 3.5:1, 4.0:1, 4.5:1, 5.0:1, 5.5:1, 6.0:1, 6.5:1, 7.0:1 or 7.5:1, but not limited to the listed values, other unlisted values within the range are also applicable.

[0009] The utility model designs the first side face and the second side face of battery piece as having different recess structure, increases the light reflection and refraction path in battery piece, effectively improves light absorption rate, compared to the structure of the first recess distributed in the first side face, the structure and size of the second recess distributed in the second side face present higher uniformity, ensure the passivation protection effect when being overlapped with photovoltaic solder strip.

[0010] It should be noted that the area ratio of the several first recess distributed in the first side face refers to the ratio of the total area of all first recesses in the first side face; The area ratio of the several second recess distributed in the second side face refers to the ratio of the total area of all second recesses in the second side face.

[0011] In the utility model, the first side face is the side surface overlapped with photovoltaic solder strip when encapsulating to form photovoltaic module, and the second side face intersects with the first side face.

[0012] As a preferred technical scheme of the utility model, the total area of the several first recesses is 40%~80% of the area of the first side face, for example, it can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 80%, but not limited to the listed values, other unlisted values within the range are also applicable.

[0013] The total area of the several first recesses refers to the total area of all first recesses.

[0014] As an optimal technical scheme of the utility model, the total area of the plurality of second recessed parts is 10% to 50% of the area of the second side face, for example, can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0015] The total area of the plurality of second recessed parts refers to the total area of all second recessed parts.

[0016] As an optimal technical scheme of the utility model, the plurality of first recessed parts comprises a plurality of first tower base structures and a plurality of first stacked tower bases, and the second stacked tower base is formed by stacking at least two first tower base structures in the direction of the solar cell piece interior. The plurality of second recessed parts comprises a plurality of second tower base structures and a plurality of second stacked tower bases, and the second stacked tower base is formed by stacking at least two second tower base structures in the direction of the solar cell piece interior. The average recess depth of the plurality of first stacked tower bases distributed on the first side face is less than the average recess depth of the plurality of second stacked tower bases distributed on the second side face.

[0017] In the utility model, the first side face and the light receiving side face of the solar cell piece are both distributed with single tower base structures and stacked tower base structures, and the surface roughness increases with the increase of the stacking rate of the tower base structure. By increasing the roughness of the second side face, the reflection and refraction path of incident light on the side face is greatly increased, effectively improving the light absorption amount. At the same time, by reducing the roughness of the first side face, a passivation protection effect is achieved during the lapping process with the photovoltaic welding strip, avoiding the occurrence of electric leakage problems.

[0018] As an optimal technical scheme of the utility model, the total area of the plurality of first tower base structures is 20% to 70% of the area of the first side face, for example, can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% or 70%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0019] The total area of the plurality of second tower base structures is 5% to 35% of the area of the second side face, for example, can be 5%, 10%, 15%, 20%, 25%, 30% or 35%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0020] As an optimal technical scheme of the utility model, the average tower base area of the first tower base structure is 150 to 550 μm 2 , for example, can be 150 μm 2 , 200 μm 2, 250 μm 2 , 300 μm 2 , 350 μm 2 , 400 μm 2 , 450 μm 2 , 500 μm 2 or 550 μm 2 but not limited to the listed values, other unlisted values within the range are also applicable.

[0021] The average tower base area of the second tower base structure is 200-500 μm 2 , for example, can be 200 μm 2 , 250 μm 2 , 300 μm 2 , 350 μm 2 , 400 μm 2 , 450 μm 2 or 500 μm 2 but not limited to the listed values, other unlisted values within the range are also applicable.

[0022] As a preferred technical scheme of the present application, the tower base area ratio of the plurality of first stacked tower bases distributed in the first side is less than the tower base area ratio of the plurality of second stacked tower bases distributed in the second side.

[0023] As a preferred technical scheme of the present application, the number of first tower base structures or second tower base structures stacked in a unit area is referred to as a stacking rate; the stacking rate of the first tower base structures in the first side is less than the stacking rate of the second tower base structures in the second side.

[0024] As a preferred technical scheme of the present application, the stacking rate of the first tower base structures in the first side is 30%-80%, for example, can be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 80% but not limited to the listed values, other unlisted values within the range are also applicable.

[0025] The stacking rate of the second tower base structures in the second side is 65%-95%, for example, can be 65%, 70%, 75%, 80%, 85% or 95% but not limited to the listed values, other unlisted values within the range are also applicable.

[0026] The present application controls the stacking rate of the tower base structures in the first side and the second side within the above range, ensures the light absorption rate of the side of the battery sheet, at the same time increases the passivation protection effect of the first side, and reduces the risk of electric leakage when packaging the photovoltaic module.

[0027] As one preferred technical scheme of the utility model, the first side is provided with a first step part, the first step part is arranged close to the light receiving surface side of the solar cell piece and extends along a first direction.

[0028] The second side is provided with a second step part, the second step part is arranged close to the light receiving surface side of the solar cell piece and extends along a second direction.

[0029] The first direction is perpendicular to the second direction.

[0030] The utility model discloses a step structure is arranged on the side wall surface of solar cell piece close to the light receiving surface side, can avoid that the side surface recess part is destroyed by outside, guarantees the side surface roughness.

[0031] As one preferred technical scheme of the utility model, in the third direction, the average width of the first step part is 1%~25% of the width of the first side, for example, can be 1%, 2%, 5%, 10%, 12%, 15%, 18%, 20%, 22% or 25%, but is not only limited to the enumerated numerical value, and other unenumerated numerical value in the numerical range is applicable.

[0032] In the third direction, the average width of the second step part is 1%~25% of the width of the second side, for example, can be 1%, 2%, 5%, 10%, 12%, 15%, 18%, 20%, 22% or 25%, but is not only limited to the enumerated numerical value, and other unenumerated numerical value in the numerical range is applicable.

[0033] The first direction, the second direction and the third direction are perpendicular to each other.

[0034] The third direction is the thickness direction of the solar cell piece.

[0035] As one preferred technical scheme of the utility model, the first side is also distributed with a plurality of first bosses, and the second side is also distributed with a plurality of second bosses, the density of the first boss distributed in the first side is less than the density of the second boss distributed in the second side, and the first boss and the second boss are all spherical structures.

[0036] The utility model introduces boss structure in the second side and the first side, further increases surface roughness, also reduces the reflection of incident light, strengthens light refraction effect, and enhances light absorption rate.

[0037] As one preferred technical scheme of the utility model, the first side is also distributed with a plurality of first bosses, and the second side is also distributed with a plurality of second bosses, the density of the first boss distributed in the first side is less than the density of the second boss distributed in the second side, and the first boss and the second boss are all spherical structures.

[0038] The utility model provides a kind of photovoltaic module, the photovoltaic module includes the solar cell piece of the first aspect.

[0039] Compared with prior art, the utility model has the beneficial effects that:

[0040] The solar cell piece and photovoltaic module provided by the utility model can strengthen the refraction of incident light on the side surface, reduce light reflection, increase light absorption amount, effectively improve cell piece light conversion effect, simultaneously increase the passivation protection effect of the first side surface of the lap photovoltaic welding band, avoid the leakage problem in the process of encapsulating photovoltaic module, improve the quality of module. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The structure diagram of the solar cell piece provided for embodiment 1.

[0042] Figure 2 The scanning electron microscope representation diagram of the first side surface of the solar cell piece provided for embodiment 1 under 500 times magnification.

[0043] Figure 3 The scanning electron microscope representation diagram of the second side surface of the solar cell piece provided for embodiment 1 under 500 times magnification.

[0044] Figure 4 The scanning electron microscope representation diagram of the first side surface of the solar cell piece provided for embodiment 2 under 500 times magnification.

[0045] Figure 5 The scanning electron microscope representation diagram of the second side surface of the solar cell piece provided for embodiment 2 under 500 times magnification.

[0046] Wherein, 100-light receiving surface;200-backlight surface;300-first side surface;400-second side surface;11-first tower base structure;12-first stacked tower base;13-first step portion;14-first boss;21-second tower base structure;22-second stacked tower base;23-second step portion;24-second boss. DETAILED DESCRIPTION

[0047] It should be understood that, in the description of the present application, the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" 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 present application and simplifying the description, and therefore cannot be understood as indicating or implying 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 limiting the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" and the like can be explicitly or implicitly included one or more features. In the description of the present application, "a plurality of", "several" means two or more, unless otherwise specified.

[0048] The technical solutions of the present application will be further illustrated below in conjunction with the drawings and through specific embodiments.

[0049] In one embodiment, the present application provides a solar cell having a light-receiving surface and a back surface arranged opposite to each other, and a side wall surface located between the light-receiving surface and the back surface, and the side wall surface is connected to the light-receiving surface and the back surface respectively. The side wall surface includes at least one first side surface and a second side surface arranged adjacent to the first side surface, the first side surface is overlapped with the solder strip, and the second side surface is a near-light surface. Sunlight enters the cell from the light-receiving surface, and the second side surface can refract light to increase the light absorption amount of the cell. The second side surface is distributed with a plurality of second recesses, the first recesses and the second recesses are independently recessed towards the inside of the solar cell; the area ratio of the plurality of first recesses distributed in the first side surface to the area ratio of the plurality of second recesses distributed in the second side surface is (1.5~7.5):1.

[0050] It should be noted that the present application does not make specific limitations on the shape, size, area and the like of the first side surface and the second side surface. In addition, the shape of the solar cell includes but is not limited to a cuboid or a cube, and the present application does not make any specific limitation on this. Taking the solar cell with a cuboid structure as an example, the first side surface can be a side surface in the width direction of the cell (i.e. a short side), or a side surface in the length direction of the cell (i.e. a long side), and at the same time, the second side surface can be a side surface in the length direction of the cell (i.e. a long side), or a side surface in the width direction of the cell (i.e. a short side).

[0051] Specifically, the total area of the plurality of first recesses is 40%~80% of the area of the first side surface.

[0052] Specifically, the total area of the plurality of second recesses is 10% to 50% of the area of the second side surface.

[0053] The plurality of first recesses includes a plurality of first tower base structures and a plurality of first stacked tower bases, and the first stacked tower bases are formed by stacking at least two first tower base structures in the direction of the interior of the solar cell wafer. The first tower base structure has a quadrilateral-like projection on the first side surface, and the first stacked tower base includes at least two first tower base structures, so that the projection on the first side surface is an irregular polygon, and the recess depth is greater than that of the first tower base structure. There are both single first tower base structure topography and stacked topography formed by at least two first tower base structures in the first side surface, so as to form a rough surface. The first tower base structure of each layer in the first stacked tower base is stacked at a certain angle with the first tower base structure of the adjacent layer, or is stacked at the same angle, so as to form a polygonal structure. The number of stacked first tower base structures in the first stacked tower base includes but is not limited to 2, 3, 4, 5, 6, 8, 10 or 12, etc., to form irregular triangles, quadrilaterals, pentagons, hexagons, octagons, decagons, dodecagons, and other polygons.

[0054] Similarly, the plurality of second recesses includes a plurality of second tower base structures and a plurality of second stacked tower bases, and the second stacked tower bases are formed by stacking at least two second tower base structures in the direction of the interior of the solar cell wafer. The second tower base structure has a quadrilateral-like projection on the second side surface, and the second stacked tower base includes at least two second tower base structures, so that the projection on the second side surface is an irregular polygon, and the recess depth is greater than that of the second tower base structure. There are both single second tower base structure topography and stacked topography formed by at least two second tower base structures in the second side surface, so as to form a rough surface. The second tower base structure of each layer in the second stacked tower base is stacked at a certain angle with the second tower base structure of the adjacent layer, or is stacked at the same angle, so as to form a polygonal structure. The number of stacked second tower base structures in the second stacked tower base includes but is not limited to 2, 3, 4, 5, 6, 8, 10 or 12, etc., to form irregular triangles, quadrilaterals, pentagons, hexagons, octagons, decagons, dodecagons, and other polygons.

[0055] The proportion of the first tower base structure distributed in the first side surface is also different from the proportion of the second tower base structure distributed in the second side surface. The total area of the plurality of first tower base structures is 20% to 70% of the area of the first side surface, and the total area of the plurality of second tower base structures is 5% to 35% of the area of the second side surface.

[0056] Specifically, the average base area of ​​the first tower base structure is 150~550 μm. 2 The average base area of ​​the second tower base structure is 200~500μm. 2 .

[0057] The proportion of the base area of ​​the plurality of first stacked tower bases distributed within the first side is smaller than the proportion of the base area of ​​the plurality of second stacked tower bases distributed within the second side. That is, the proportion of the total base area of ​​all first stacked tower bases in the area of ​​the first side is smaller than the proportion of the total base area of ​​all second stacked tower bases in the area of ​​the second side. Compared to the first side, the proportion of the second towers with near-quadrilateral shapes on the second side is smaller, resulting in a relatively uneven size distribution and irregular structure. This increases the roughness of the second side, which is beneficial for increasing the light refraction path.

[0058] The number of the first tower base structure or the second tower base structure stacked within a unit area is recorded as the stacking rate. The stacking rate of the first tower base structure in the first side is less than the stacking rate of the second tower base structure in the second side. On the one hand, this avoids too few stacked morphologies in the second side, which would reduce the light absorption capacity of the solar cells. On the other hand, it prevents too many stacked morphologies in the first side, which would worsen the passivation effect.

[0059] Specifically, the stacking rate of the first tower base structure in the first side is 30%~80%, and the stacking rate of the second tower base structure in the second side is 65%~95%, in order to balance the light absorption effect and passivation performance of the second side of the solar cell.

[0060] In some embodiments, the first side has a first stepped portion, which is located near the light-receiving surface of the solar cell and extends along a first direction. The second side has a second stepped portion, which is located near the light-receiving surface of the solar cell and extends along a second direction. The first direction is perpendicular to the second direction. Both the second and first sides of this invention have stepped portions to form a blocking structure, preventing the tower-like structure on the sides from being cleaned or damaged during the cell manufacturing process or application.

[0061] Specifically, in the third direction, the average width of the first step is 1% to 25% of the width of the first side, and the average width of the second step is 1% to 25% of the width of the second side. The first direction, the second direction, and the third direction are mutually perpendicular. The third direction is the thickness direction of the solar cell.

[0062] Further, the first side surface is also distributed with a plurality of first protrusions, and the second side surface is also distributed with a plurality of second protrusions. Specifically, the first protrusions and the second protrusions are both in a pyramid shape. The introduction of the protrusion structure in the first side surface and the second side surface can further improve the surface roughness, strengthen the refraction of the incident light by the side surface, and increase the amount of light absorption.

[0063] Further, the first side surface is also distributed with a plurality of first protrusions, and the second side surface is also distributed with a plurality of second protrusions. Specifically, the first protrusions and the second protrusions are both in a pyramid shape. The introduction of the protrusion structure in the first side surface and the second side surface can further improve the surface roughness, strengthen the refraction of the incident light by the side surface, and increase the amount of light absorption.

[0064] In another specific embodiment, the utility model provides a photovoltaic module, the photovoltaic module includes the solar cell piece in one specific embodiment.

[0065] The photovoltaic module also includes a plurality of photovoltaic welding strips, which can lap the first side surface of the solar cell piece in the packaging process to lead out and collect current.

[0066] Embodiment 1

[0067] The embodiment provides a solar cell piece, which comprises a light-receiving surface and a back surface arranged oppositely, and a side wall surface between the light-receiving surface and the back surface. Figure 1 As shown in the figure, the side wall surface has a first side surface and a second side surface arranged adjacent to the first side surface, and the first side surface is lapped with a photovoltaic welding strip of a photovoltaic module.

[0068] As shown in the figure, the first side surface is distributed with a plurality of first recesses, and the total area of all the first recesses is 50% of the area of the first side surface. Figure 2 As shown in the figure, the first side surface is distributed with a plurality of first recesses, and the total area of all the first recesses is 50% of the area of the first side surface. 2The first stacked tower base 12 has an irregular polygonal orthographic projection on the first side 300. The number of first tower base structures 11 stacked per unit area is denoted as the stacking rate. The stacking rate of the first stacked tower bases 12 distributed on the first side 300 is 30%.

[0069] like Figure 3 As shown, the second side surface 400 has multiple second recesses, the total area of ​​which is 20% of the area of ​​the second side surface 400. Some of the second recesses are formed by a single second base structure 21, while others are formed by stacking at least two second base structures 21 towards the interior of the solar cell, creating a second stacked base 22. The second base structures 21 are approximately quadrilateral in shape and recessed towards the interior of the solar cell. The total base area of ​​all the second base structures 21 is 25% of the area of ​​the second side surface 400. The average base area of ​​a single second base structure 21 in the multiple second recesses of the second side surface 400 is 370 μm². 2 The second stacked tower base 22 has an irregular polygonal orthographic projection on the second side 400. The number of second stacked tower base structures 21 stacked per unit area is denoted as the stacking rate; the stacking rate of the second stacked tower bases 22 distributed on the second side 400 is 30%. The area ratio of all first stacked tower bases 12 distributed within the first side 300 is less than the area ratio of all second stacked tower bases 22 distributed within the second side 400.

[0070] The first side surface 300 is further provided with a first step portion 13, which is located near the light-receiving surface 100 of the solar cell and extends along the first direction X. The second side surface 400 is provided with a second step portion 23, which is located near the light-receiving surface 100 of the solar cell and extends along the second direction Y. In the third direction Z, the average width of the first step portion 13 is 15% of the width of the first side surface 300, and the average width of the second step portion 23 is 15% of the width of the second side surface 400. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other, and the third direction Z is the thickness direction of the solar cell.

[0071] Example 2

[0072] This embodiment provides a solar cell, which differs from Embodiment 1 in that: Figure 4 and Figure 5 As shown, the first side 300 is also provided with a plurality of first protrusions 14 in a spherical structure, and the second side 400 is also provided with a plurality of second protrusions 24 in a spherical structure. The density of the first protrusions 14 distributed in the first side 300 is less than the density of the second protrusions 24 distributed in the second side 400. The rest of the structure is the same as in Embodiment 1.

[0073] Example 3

[0074] This embodiment provides a solar cell, which is different from the embodiment 2 in that the first side surface is further provided with a plurality of first protrusions in the shape of pyramid, and the second side surface is further provided with a plurality of second protrusions in the shape of pyramid, and the rest of the structure is the same as the embodiment 2.

[0075] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by any person skilled in the art, and all of them fall within the protection scope and disclosure scope of the present application.

Claims

1. A solar cell, characterized by, The solar cell has at least one first side surface and a second side surface adjacent to the first side surface, the first side surface is overlapped with the solder strip, and the second side surface is a near-light surface; the first side surface is distributed with a plurality of first recesses, the second side surface is distributed with a plurality of second recesses, and the first recesses and the second recesses are independently recessed towards the inside of the solar cell; The area ratio of the plurality of first recesses distributed in the first side surface to the plurality of second recesses distributed in the second side surface is (1.5-7.5):

1.

2. The solar cell according to claim 1, wherein The total area of the plurality of first recesses is 40%-80% of the area of the first side surface.

3. The solar cell according to claim 1 or 2, characterized in that, The total area of the plurality of second recesses is 10%-50% of the area of the second side surface.

4. The solar cell of claim 1, wherein, The plurality of first recesses includes a plurality of first tower base structures and a plurality of first stacked tower bases, and the first stacked tower bases are formed by stacking at least two first tower base structures towards the inside of the solar cell; The plurality of second recesses includes a plurality of second tower base structures and a plurality of second stacked tower bases, and the second stacked tower bases are formed by stacking at least two second tower base structures towards the inside of the solar cell; The average recess depth of the plurality of first stacked tower bases distributed in the first side surface is less than the average recess depth of the plurality of second stacked tower bases distributed in the second side surface.

5. The solar cell of claim 4, wherein, The total tower area of the plurality of first tower base structures is 20%-70% of the area of the first side surface. The total tower area of the plurality of second tower base structures is 5%-35% of the area of the second side surface.

6. The solar cell according to claim 4 or 5, characterized in that, The average footing area of the first footing structure is 150-550 μm 2 ; The average footing area of the second footing structure is 200-500 μm 2 .

7. The solar cell of claim 4, wherein, The tower area ratio of the plurality of first stacked tower bases distributed in the first side surface is less than the tower area ratio of the plurality of second stacked tower bases distributed in the second side surface.

8. The solar cell of claim 4, wherein, The number of the first tower base structures or the second tower base structures stacked per unit area is referred to as a stacking rate; The stacking rate of the first tower base structures in the first side surface is less than the stacking rate of the second tower base structures in the second side surface.

9. The solar cell of claim 8, wherein, The stacking rate of the first tower base structures in the first side surface is 30%-80%; The stacking rate of the second tower base structures in the second side surface is 65%-95%.

10. The solar cell of claim 1, wherein, The first side surface is provided with a first step portion, the first step portion is arranged close to the light-receiving surface side of the solar cell and extends along a first direction; The second side surface is provided with a second step portion, the second step portion is arranged close to the light-receiving surface side of the solar cell and extends along a second direction; The first direction is perpendicular to the second direction.

11. The solar cell of claim 10, wherein, In a third direction, the average width of the first step portion is 1%-25% of the width of the first side surface; In the third direction, the average width of the second step portion is 1%-25% of the width of the second side surface; The first direction, the second direction and the third direction are perpendicular to each other.

12. The solar cell of claim 1, wherein, The first side surface is also distributed with a plurality of first bosses, and the second side surface is also distributed with a plurality of second bosses. The density of the first bosses distributed in the first side is less than the density of the second bosses distributed in the second side. The first bosses and the second bosses are spherical structures.

13. The solar cell according to claim 1 or 12, wherein The first side is further provided with a plurality of first protrusions, and the second side is further provided with a plurality of second protrusions. The first protrusions and the second protrusions are pyramid-shaped.

14. A photovoltaic module, characterized by, The photovoltaic module comprises the solar cell sheet according to any one of claims 1-13.

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