Photovoltaic cell and photovoltaic module

Abstract

Photovoltaic cell, comprehensive: a substrate having a first surface and a second surface opposite each other, the first surface having first regions and second regions arranged alternately in a first direction; and Grooves arranged in the substrate at the second regions and embedded in the substrate, wherein a single groove of the grooves has a bottom surface and an inclined surface connecting the bottom surface to a first region adjacent to the bottom surface, the inclined surface being inclined in the direction of the first region; where the ground surface is provided as a first textured surface with several first pyramids, and the first region is provided as a third textured surface with several third pyramids.

Description

TECHNICAL AREA

[0001] The present disclosure relates to the field of photovoltaic technology, in particular to a photovoltaic cell, a method for manufacturing the photovoltaic cell and a photovoltaic module. BACKGROUND

[0002] With the gradual depletion of fossil fuels, photovoltaic cells are increasingly being used as a new energy alternative, converting sunlight into electrical energy. Photovoltaic cells utilize the photovoltaic principle to generate charge carriers and then employ electrodes to dissipate these charge carriers, thus facilitating the efficient use of electrical energy. SUMMARY

[0003] Embodiments of the present disclosure provide a photovoltaic cell, a method for manufacturing the photovoltaic cell and a photovoltaic module which are at least advantageous in improving the overall flatness of the second regions while improving the light-capturing effect of the entire first surface.

[0004] According to some embodiments of the present disclosure, a photovoltaic cell is provided. The photovoltaic cell comprises a substrate with a first surface and a second surface facing each other, the first surface having first regions and second regions arranged alternately in a first direction; grooves arranged in the substrate at the second regions and recessed into the substrate, each groove comprising a bottom surface and an inclined surface connecting the bottom surface to a first region adjacent to the bottom surface; the inclined surface being a smooth inclined surface and inclined in the direction of the first region.The ground surface is designed as a first textured surface with several first pyramids, and the first region is designed as a third textured surface with several third pyramids.

[0005] In some embodiments, in the same groove along the first direction, a length of the bottom surface is the first length and a length of the inclined surface is the second length, and a ratio of the second length to the first length is in the range of 0.001 to 0.005.

[0006] In some embodiments, the depth of the groove along the second direction, which is a thickness direction of the substrate, is in the range of 2 µm to 4 µm.

[0007] In some embodiments, the angle of inclination of the surface inclined towards the first region is between 40° and 55°.

[0008] In some embodiments, the photovoltaic cell also includes a first protective layer that covers the ground surface and the inclined surface.

[0009] In some embodiments, the first protective layer consists of a semiconductor material doped with a doping element, silicon oxide, phosphosilicate glass or borosilicate glass.

[0010] In some embodiments, a single groove comprises at least two inclined surfaces and a stepped surface connecting two adjacent inclined surfaces; the bottom surface, the at least two inclined surfaces, and the stepped surface together form the groove; and the stepped surface is provided as a second textured surface containing multiple second pyramids, wherein a base size of a single first pyramid is larger than a base size of a single second pyramid and a height of a single first pyramid is greater than a height of a single second pyramid.

[0011] In some embodiments, several inclined surfaces and stepped surfaces connecting adjacent inclined surfaces in the same groove jointly form a slope, wherein an orthographic projection surface of the slope on the floor surface is a first surface, a surface of the floor surface is a second surface, and a ratio of the first surface to the second surface is in the range of 0.005 to 0.02.

[0012] In some embodiments, the substrate arranged in the second region comprises two inclined surfaces and a stepped surface connecting two adjacent inclined surfaces; wherein, along a second direction, which is a thickness direction of the substrate, a distance between the stepped surface and the first region is a first distance, and a distance between the stepped surface and the ground surface is a second distance, and the ratio between the first distance and the second distance is in the range of 0.6 to 1.3.

[0013] In some embodiments, the first pyramids and the third pyramids satisfy any or any combination of the following relationships: The base size of a single third pyramid is smaller than the base size of a single first pyramid; The height of a single third pyramid is less than the height of a single first pyramid; The reflectivity of the third textured surface is lower than the reflectivity of the first textured surface; and The vertex angles of the first and third pyramids lie in a range of 65° to 80°.

[0014] In some embodiments, the photovoltaic cell further comprises: electrodes arranged at least on the first surface, wherein the electrodes are used to extract the photogenerated charge carriers generated in the substrate, wherein the first regions include at least regions where the orthographic projections of the electrodes are arranged on the substrate.

[0015] In some embodiments, the photovoltaic cell further comprises: a tunneling layer that is arranged on the second surface; a first doped semiconductor layer, which is doped with a first doping element and is located on a side of the tunneling layer away from the second surface; a second doped semiconductor layer doped with a second doping element and arranged on the first regions, wherein a conductivity type of the first doping element differs from a conductivity type of the second doping element; a first passivation layer located on a side of the first doped semiconductor layer away from the tunneling layer; a second passivation layer, which is arranged on a side of the second doped semiconductor layer away from the substrate and is located on the second regions; first electrodes that are in ohmic contact with the first doped semiconductor layer; and second electrodes that are embedded in the second passivation layer and are in ohmic contact with the second doped semiconductor layer.

[0016] In some embodiments, the photovoltaic cell further comprises: a tunneling layer that is arranged on the second surface; a first doped semiconductor layer, which is doped with a first doping element and is located on a side of the tunneling layer away from the second surface; a second doped semiconductor layer doped with a second doping element and arranged on the first regions, wherein a conductivity type of the first doping element differs from a conductivity type of the second doping element; a first protective layer that is arranged on the second regions; a first passivation layer located on a side of the first doped semiconductor layer away from the tunneling layer; a second passivation layer located on the side of the second doped semiconductor layer furthest from the substrate and positioned on the second regions; first electrodes embedded in the first passivation layer and in ohmic contact with the first doped semiconductor layer; and second electrodes that are in ohmic contact with the second doped semiconductor layer.

[0017] According to some embodiments of this disclosure, the present disclosure comprises: Providing an initial substrate, wherein the initial substrate has an initial first surface and an initial second surface opposite each other, the initial first surface having initial first regions and initial second regions arranged alternately along a first direction; Irradiating the initial second regions using a laser spot with a gradual change in energy to convert a section of the thickness of the initial substrate located in the initial second regions into a damage layer, wherein the change in energy of the laser spot in a direction from the center of the laser spot to the edge comprises at least a first stage I, a second stage II and a third stage III in a sequential manner, wherein the energy of the laser spot in the first stage I is at a first preset value, the energy of the laser spot in the second stage II gradually increases from the first preset value to a second preset value, and the energy of the laser spot in the third stage III gradually decreases from the second preset value to zero; wherein each initial second region is subjected to a first textured process to remove at least the damage layer and form a groove in the second region, wherein the remaining initial substrate is the substrate, the initial first region is converted into the first region of the substrate, and the initial second region is converted into the second region of the substrate, and the substrate has a bottom surface recessed towards the interior of the substrate in the second region, and a smooth inclined surface connecting the bottom surface and the first region, wherein the smooth inclined surface is inclined towards the first region, and the bottom surface and the smooth inclined surface enclose the groove; where the ground surface is provided as a first textured surface with several first pyramids, and the region is provided as a third textured surface with several third pyramids.

[0018] In some embodiments, the energy of the laser spot is the irradiance of the laser spot, wherein the irradiance of the laser spot decreases by 0.016 J / mm² along the direction from the center to the edge of the laser spot. 2 down to 0.095 J / mm 2 The irradiance of the laser spot is increased by 0.01 J / mm² per 1 µm distance in the second stage II. 2 up to 0.04 J / mm 2 per 1 µm distance in the third stage III is reduced; and / or the first preset value is in the range of 0.01J / mm 2 down to 0.02 J / mm 2 lies, and the second preset value is in the range of J / mm 2 up to 0.2 J / mm 2 lies.

[0019] In some embodiments, the first etching solution used in the first texturing treatment contains potassium hydroxide and water, and the ratio of potassium hydroxide to water is in the range of 0.002:1 to 0.01:1; and / or the treatment duration of the first texturing treatment is in the range of 100 s to 200 s; and / or the process temperature of the first texturing treatment is 65°C to 75°C.

[0020] In some embodiments, the present disclosure further includes: Performing a high-temperature treatment or high-temperature doping treatment on the grooves to form a first protective layer covering the bottom surface and the smooth inclined surface; Forming a first doped semiconductor layer on the second surface, wherein the first doped semiconductor layer is also arranged on a section of the first surface; and Performing an etching process on the first doped semiconductor layer located on the first surface, with the first protective layer acting as the etch barrier layer.

[0021] In some embodiments, the process temperature of the high-temperature treatment or the high-temperature doping treatment is in the range of 900°C to 1050°C and the treatment duration is in the range of 2000 s to 5000 s.

[0022] In some embodiments, the present disclosure further comprises, after the provision of the initial substrate and before the irradiation of the initial second region with a laser spot with a gradual energy change: Performing a second texturing treatment on the first surface, such that the first surface has multiple third pyramids; and Performing a doping treatment on the first surface to convert a section of the thickness of the first substrate into the second doped semiconductor layer, and forming a second protective layer on a side of the second doped semiconductor layer away from the first substrate; when performing the first texturing treatment on the initial second regions, retaining the second doped semiconductor layer arranged in the initial first regions, with the second protective layer acting as the etch barrier layer, and forming a third textured surface that has multiple third pyramids through the initial first regions.

[0023] According to some embodiments of the present disclosure, a further aspect of the embodiments of the present disclosure further provides a photovoltaic module comprising: at least one cell string, each formed by connecting several photovoltaic cells as described above, at least one encapsulation adhesive film configured to cover a surface of the at least one cell string, and at least one cover plate configured to cover a surface of the at least one encapsulation adhesive film facing away from the at least one cell string.

[0024] The technical solutions in this disclosure have at least the following advantages.

[0025] To prevent the entire second region from having a pyramid-shaped surface, the transition area between the ground surface and the first region is designed as a smooth, sloping surface. On the one hand, a difference in elevation between the ground surface and the first region is advantageous because the smooth, sloping surface allows for the efficient reflection of light not absorbed by the ground surface. This ensures that the light is ultimately reflected and absorbed by the first region, or the ground surface, and utilized. This maximizes light utilization and reduces overall light reflection loss in the first region.On the other hand, light incident obliquely to the first direction onto the second region can change its angle through reflection from the smooth, inclined surface and is more likely to be absorbed by the base surface designated as the first textured surface, or more likely by the first region designated as the second textured surface. In this case, the first surface as a whole can receive light at more angles of incidence, thus reducing light emission. This further reduces the reflection loss of light on the first surface and improves the photoelectric conversion efficiency of the photovoltaic cell under weak or oblique lighting conditions. Furthermore, the smooth, inclined surface is advantageous for improving the overall flatness of the second region.When a film layer forms on the first surface, the smooth, inclined surface allows it to transition gently from the first region to the bottom surface, which is advantageous for forming a film layer of uniform thickness on the first surface. The smooth, inclined surface can reduce the degree of stress concentration during film deposition, thereby reducing the risk of film cracking or delamination. Furthermore, the smooth, inclined surface allows photogenerated charge carriers in the second region to migrate quickly to the nearest first region, thus reducing the lateral transfer distance of the photogenerated charge carriers and consequently decreasing the probability of their recombination.Furthermore, it is advantageous to use the smooth inclined surface as a channel for guiding the photogenerated charge carriers, thus avoiding the problem of local concentration of photogenerated charge carriers caused by the conventionally textured surface, thereby improving the fill factor of the photovoltaic cell and improving the photoelectric conversion efficiency of the photovoltaic cell.

[0026] Furthermore, the groove arranged in the second region helps to increase the number of reflections and / or scatterings of light in the second region and to increase the surface area of ​​the second region for light absorption, thus further enhancing the light-capturing effect of the second region on the light. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] One or more embodiments are described by way of example with reference to the corresponding figures in the accompanying drawings, and this exemplary description is not to be understood as limiting the embodiments. Elements in the accompanying drawings that have the same reference numerals are represented as similar elements, and unless expressly stated otherwise, the figures in the accompanying drawings are not drawn to scale. In order to describe the technical solutions of the embodiments of this disclosure or of the relevant prior art more clearly, the accompanying drawings that must be used for the embodiments are briefly described below. Obviously, the accompanying drawings described below represent only some embodiments of this disclosure.Experts can also obtain other drawings from the attached drawings without any creative effort. Fig. Figure 1 is a schematic diagram showing a first partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 2 is a schematic diagram showing a first enlarged view of a substrate in which the Fig. 1 shows the dashed box C. Fig. Figure 3 is a schematic diagram of a three-dimensional scanning electron microscopy (SEM) image of a substrate in a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 4 is a schematic diagram showing a second partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 5 is a schematic diagram showing a third partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 6 is a schematic diagram showing a partial sectional view of an initial substrate provided in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 7 is a schematic diagram showing a partial cross-section of a damage layer formed in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 8 is a curve diagram representing the energy gradient of a laser spot in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 9 is a schematic diagram showing a partial sectional view of the formation of a first doped semiconductor layer on a substrate. Fig. The structure shown in section 4 is shown. Fig. Figure 10 is a schematic diagram showing a partial sectional view of the execution of an etching process on a surface in Fig. The structure shown in 9 is shown. Fig. Figure 11 is a schematic diagram showing a partial sectional view of the formation of a second doped semiconductor layer and a second protective layer on an initial substrate in a method for producing a photovoltaic cell according to a further embodiment of the present disclosure. Fig. Figure 12 is a schematic diagram showing a perspective partial view of a photovoltaic module according to a further embodiment of the present disclosure. Fig. Figure 13 is a schematic diagram showing a structural cross-sectional view of the photovoltaic module along line MM1 in Fig. 12 shows. Fig. Figure 14 is a schematic diagram showing a fourth partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 15 is a schematic diagram showing a fifth partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 16 is a schematic diagram showing a sixth partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 17 is a schematic diagram showing a first enlarged view of the substrate in which Fig. The dashed box B shown in 16 is shown. Fig. Figure 18 is a schematic diagram showing a second enlarged view of the substrate in which the Fig. The dashed box B shown in 16 is shown. Fig. Figure 19 is another schematic diagram of a three-dimensional scanning electron microscopy (SEM) of a substrate in a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 20 is a schematic diagram showing a seventh partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF EXECUTION FORMS

[0028] As is known from the background, the light absorption efficiency and the photoelectric conversion efficiency of photovoltaic cells need to be improved.

[0029] The photovoltaic cell, the method for manufacturing the photovoltaic cell, and the photovoltaic module are provided in the embodiments of the present disclosure. In the photovoltaic cell, the transition area between the ground surface and the first region is designed as a smooth, inclined surface to avoid the entire second region having a pyramid-shaped surface. On the one hand, a height difference between the ground surface and the first region is advantageous in order to utilize the smooth, inclined surface to efficiently reflect the light that was not absorbed by the ground surface, so that the light is ultimately reflected to the first region or the ground surface, where it is absorbed and utilized. This is advantageous in reducing the overall reflection loss of the light in the first region.On the other hand, light striking the second region at an angle to the first can change its angle through reflection from the smooth, inclined surface and is more readily absorbed by the ground surface or the first region. This allows the first surface as a whole to receive light at more angles of incidence, thus reducing light emission and further decreasing light reflection loss on the first surface. Furthermore, the smooth, inclined surface improves the overall flatness of the second region. If a film layer is then formed on the first surface, the smooth, inclined surface allows the film layer to transition smoothly from the first region to the ground surface, which is beneficial for the formation of a film layer of uniform thickness on the first surface.The smooth, inclined surface can reduce the degree of stress during film deposition, thereby reducing the risk of film tears or delamination. Furthermore, it is advantageous that the photogenerated charge carriers in the second region can migrate rapidly to the nearest first region via the smooth, inclined surface, thus reducing the lateral transmission distance of the photogenerated charge carriers and consequently decreasing the recombination probability. Additionally, using the smooth, inclined surface as a channel for guiding the photogenerated charge carriers is advantageous, thus avoiding the problem of local charge carrier concentration caused by conventionally textured surfaces. This improves the fill factor and photoelectric conversion efficiency of the photovoltaic cell.Furthermore, the groove arranged in the second region helps to increase the number of reflections and / or scatterings of light in the second region and to increase the surface area of ​​the second region for the absorption of light, thus further improving the light-capturing effect of the second region.

[0030] In the description of embodiments of this disclosure, the technical terms "first" and "second" are used only to distinguish between different objects and cannot be understood as indicating a relative meaning or implicitly indicating or implying the number, specific order, or primary-secondary relationship of the specified technical features. In the description of embodiments of this disclosure, "several" means two or more, unless expressly stated otherwise.

[0031] The reference to “embodiments” in this document means that certain features, structures, or properties described in connection with embodiments may be included in at least one embodiment of the present disclosure. The presence of the term in different places in the description does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that excludes other embodiments. A person skilled in the art understands, both explicitly and implicitly, that the embodiments described in this document may be combined with other embodiments.

[0032] In the description of the embodiments of the present disclosure, the term "and / or" is merely an associative relationship that describes the associated objects, meaning that there can be three relationships. For example, A and / or B, which can mean that there are three situations: the presence of A, the presence of A and B, and the presence of B. Furthermore, the symbol " / " generally indicates an "or" relationship between the associated objects.

[0033] In the description of the embodiments of the present disclosure, the term "multiple" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups) and "multiple layers" refers to two or more layers (including two layers).

[0034] In the description of embodiments of the present disclosure, the technical terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upwards”, “downwards”, “front”, “backwards”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, and the like are denoting orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings and serve only to facilitate and simplify the description of the embodiments of the present disclosure, and are not intended to indicate or imply that the device or element in question must have a particular orientation, be constructed and operated with a particular orientation.and therefore cannot be understood as a limitation of the embodiments of the present disclosure.

[0035] In the description of the embodiments of this disclosure, unless otherwise specified and limited, technical terms such as "installation," "connection," and "fixation" are to be understood broadly. For example, they may refer to a permanent connection, a detachable connection, or a one-piece connection. They may also refer to a mechanical connection or an electrical connection. They may refer to a direct connection, an indirect connection via an intermediate medium, internal communication between two elements, or an interaction between two elements. For the person skilled in the art, the specific meanings of the aforementioned terms in the embodiments of this disclosure are to be understood as situation-dependent.

[0036] In the drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are shown enlarged for better understanding and description. When it is described that a component (such as a layer, film, region, or substrate) is located on top of another component or on the surface of another component, the component may be located "directly" on the surface of the other component, or a third component may be located between the two components. Conversely, when it is described that a component is located on the surface of another component, or that another component is formed or provided on the surface of a component, this means that no third component is located between the two components.Furthermore, if it is described that a component is formed “essentially” on another component, this means that the component is formed neither on the entire surface (or the front surface) of another component nor on part of the edge of the entire surface.

[0037] In the description of the embodiments of the present disclosure, it is understood that if a component "contains" or "has" another component, unless otherwise specified, other components are not excluded and other components may also be included. Furthermore, if a component such as a layer, film, region, or plate is described as being arranged "on / at" another component, it may be located "directly on" another component (i.e., there is no other component between the two components on the surface of another component), or another component may be located between the two components.Furthermore, if a component such as a layer, film, region or plate is placed "directly on" another component, or if a component such as a layer, film, region or plate is placed on the surface of another component, this means that there is no other component between the two components.

[0038] The terms used in the description of various embodiments in this document serve only to describe specific embodiments and are not to be construed as limitations. As used in the description of the various embodiments and the accompanying claims, "the component" is intended to include the plural form unless otherwise specified. Components include the layer, the film, the region, or the plate.

[0039] The various embodiments of the present disclosure are described in more detail below in conjunction with the accompanying drawings. However, the person skilled in the art will understand that many technical details are included in the various embodiments of the present disclosure to facilitate the reader's understanding of these embodiments. But even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0040] One embodiment of the present disclosure provides a photovoltaic cell. The photovoltaic cell in one embodiment of the present disclosure is described in more detail below with reference to the accompanying drawings.

[0041] As in Fig. 1, Fig. 2 to Fig. As shown in Figure 3, the photovoltaic cell comprises a substrate 100 having a first surface 101 and a second surface 102 facing each other. The first surface 101 has first regions 111 and second regions 121 arranged alternately in a first direction X. The substrate 100 has a bottom surface 131 embedded in the second regions 121 and a smooth inclined surface 181 connecting the bottom surface 131 and the first region 111. The smooth inclined surface 181 and the bottom surface 131 enclose a groove 151. The smooth inclined surface 181 is inclined towards the first region 111. The bottom surface 131 is designed as a first textured surface with several first pyramidal elements 131a. The first region 111 is designed as a second textured surface with several second pyramidal elements 111a.

[0042] Fig. Figure 1 is a schematic diagram showing a first partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 2 is a schematic diagram showing an enlarged view of a substrate in which Fig. 1 shows the dashed box C. Fig. Figure 3 is a schematic diagram of a three-dimensional scanning electron microscopy (SEM) image of a substrate in a photovoltaic cell according to an embodiment of the present disclosure.

[0043] It should be noted that not only are the grooves 151 designed on the first surface 101, but also the transition area between the base surface 131 and the first region 111 is designed as a smooth, inclined surface 181 to prevent the entire second region 121 from being a pyramid-shaped surface. On the one hand, a height difference between the base surface 131 and the first region 111 is advantageous in order to utilize the smooth, inclined surface 181 to efficiently reflect the light that was not absorbed by the base surface 131, so that the light is ultimately reflected and absorbed by the first region 111 or the base surface 131 and utilized. This is advantageous for achieving extensive use of the light and reducing the overall reflection loss of the light on the first surface 101.On the other hand, the light incident obliquely to the first direction X onto the second region 121 can change its angle through reflection from the smooth inclined surface 181 and is more readily absorbed by the base surface 131, which is provided as the first textured surface with several first pyramids 131a, or more readily by the first region 111, which is provided as the second textured surface with several second pyramids 111a. Then the first surface 101 as a whole can receive light at more angles of incidence, thus reducing light emission, which further decreases the reflection loss of light on the first surface 101 and improves the photoelectric conversion efficiency of the photovoltaic cell under weak or oblique lighting conditions. Furthermore, the smooth inclined surface 181 is advantageous for improving the overall flatness of the second region 121.When a film layer is formed on the first surface 101, the smooth inclined surface 181 allows the film layer to transition smoothly from the first region 111 to the bottom surface 131, which is advantageous for the formation of a film layer of uniform thickness on the first surface 101. The smooth inclined surface 181 can reduce the degree of stress concentration during film deposition, thereby reducing the risk of film cracking or delamination. Furthermore, it is advantageous for the photogenerated charge carriers in the second region 121 to migrate rapidly to the nearest first region 111 with the aid of the smooth inclined surface 181, thus reducing the lateral transfer distance of the photogenerated charge carriers and thereby decreasing the recombination probability of the photogenerated charge carriers.Furthermore, it is advantageous to use the smooth inclined surface 181 as a channel for guiding the photogenerated charge carriers, thus avoiding the problem of local concentration of the photogenerated charge carriers caused by the conventionally textured surface, thereby improving the fill factor of the photovoltaic cell and improving the photoelectric conversion efficiency of the photovoltaic cell.

[0044] Furthermore, the groove 151 arranged in the second region 121 contributes to increasing the number of reflections and / or scatterings of light in the second region 121 and increasing the surface area of ​​the second region 121 for the absorption of light, thus further enhancing the light-capturing effect of the second region 121.

[0045] It should be noted that the smooth inclined surface 181 is smoother than the ground surface 131 with the first pyramids 131a. Due to the influence of the shaping process, the surface of the smooth inclined surface 181 is not necessarily as smooth as a polished surface, and it may also have tiny bumps or depressions without exhibiting a typical pyramidal structure. The overall smoothness, i.e., the flatness, is much higher than the flatness of the ground surface 131.

[0046] In some cases, based on the design of the surface morphology of the bottom surface 131 and the smooth inclined surface 181 enclosing the groove 151, it is advantageous to reduce the overall reflection of the second region 121 for light.

[0047] It should be noted that the photovoltaic cell also comprises electrodes arranged at least on the first surface 101, and that the electrodes serve to extract the photogenerated charge carriers produced in the substrate 100. Based on this, and to facilitate the description by a person skilled in the art of the specific orientation of the first pyramids 131a and the second pyramids 171a on the first surface 101, the first surface 101 can be subdivided into first regions 111 and second regions 121. The first regions 111 include at least the regions in which the orthographic projection of the electrodes is arranged on the substrate 100, and the regions on the first surface 101 that do not belong to the first regions 111 are the second regions 121.To ensure that the film layer in contact with the electrodes has a high doping concentration, or that the regions in contact with the electrodes are highly concentrated regions in order to reduce contact resistance, the orthographic projection area of ​​the first region 111 is generally set to be larger than or equal to the orthographic projection area of ​​the corresponding electrode. In other words, the orthographic projection area of ​​the electrode on the substrate 100 is smaller than the area of ​​the first region 111, and the orthographic projection position is necessarily located within the first region 111. It should be noted that both the number of first regions 111 and the number of second regions 121 can be multiple, and the first regions 111 and the second regions 121 are arranged alternately in the first direction X.In other words, the first region 111 can be located in an interval between adjacent second regions 121, and the second region 121 can also be located in an interval between adjacent first regions 111.

[0048] To further clarify the difference between the first pyramids 131a and the smooth inclined surface 181, the second region 121 can be subdivided into a transition region 122, a second subregion 123, and another transition region 122, arranged sequentially along the first direction X. A transition region 122 is defined as the region occupied by a smooth inclined surface 181 within the second region 121, and a second subregion 123 is defined as the region occupied by a ground surface 131 within the second region 121. In other words, the first pyramids 131a are located in the second subregion 123, and the smooth inclined surface 181 is located in the transition region 122. Furthermore, each of the two first regions 111 is connected to a corresponding transition region 122 along the first direction X on two opposite sides of the same second region 121.

[0049] The embodiments of the present disclosure are described in more detail below with reference to the accompanying drawings.

[0050] In some embodiments, such as in Fig. 1 or Fig. As shown in Figure 2, the reflectance of the first region 111, which is provided as the second textured surface, can be greater than the reflectance of the ground surface 131, which is provided as the first textured surface. In other embodiments, the reflectance of the first region, which is provided as the second textured surface, can be almost the same as the reflectance of the ground surface, which is provided as the first textured surface.

[0051] In some embodiments, the reflectance of the first region 111 is in the range of 10.5 to 11.5 and can be, for example, 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3, or 11.4, etc. The reflectance of the ground surface 131 is in the range of 10.5 to 11 and can be, for example, 10.55, 10.6, 10.65, 10.7, 10.75, 10.8, 10.85, 10.9, or 10.95, etc.

[0052] In some embodiments, such as in Fig. 2 or Fig. 3. The bases of both the first pyramid 131a and the second pyramid 111a lie in the range of 1 µm to 2 µm and can be, for example, 1.1 µm, 1.2 µm, 1.3 µm, 1.4 µm, 1.5 µm, 1.6 µm, 1.7 µm, 1.8 µm, or 1.9 µm, etc. It should be noted that while the range of values ​​for the base areas of the first pyramid 131a and the second pyramid 111a may be the same, the actual values ​​of the base areas of the first pyramid 131a and the second pyramid 111a may be either the same or different.

[0053] It should be noted that, since the bases of both the first pyramids 131a and the second pyramids 111a are relatively small, the arrangement numbers of both the first pyramids 131a and the second pyramids 111a are relatively low within the same arrangement area. On the one hand, it is advantageous to increase the surface area and specific surface area of ​​the ground surface 131 and the first region 111, so that the ground surface 131 and the first region 111 have more surfaces for receiving incident light, thereby improving the ability to receive the light reflected from the smooth inclined surface 181, and it is advantageous that more light can be absorbed and utilized by the ground surface 131 and the first region 111.On the other hand, it is advantageous to reduce the gaps between adjacent first pyramids 131a and the gaps between adjacent second pyramids 111a, so that the soil surface 131 and the first region 111 can absorb incident light more effectively, thereby reducing the likelihood of light escaping between adjacent first pyramids 131a or adjacent second pyramids 111a. Furthermore, a greater number of first pyramids 131a and a greater number of second pyramids 111a can be arranged to scatter the incident light more evenly, allowing it to easily penetrate the substrate 100 to be absorbed and utilized.On the other hand, it is advantageous to reduce the sensitivity of the ground surface 131 and the first region 111 to the angle of incidence of the incident light, so that the ground surface 131 and the first region 111 can maintain a relatively high absorption rate for light under different illumination angles.

[0054] For example, the bases of both the first pyramid 131a and the second pyramid 111a can be quadrilaterals with a size of 1.5 µm × 1.5 µm.

[0055] It should be noted that the base of the pyramid structure comprises the length, width, or diagonal of the orthogonal projection pattern of the base surface of the pyramid structure onto the second surface 102. For example, the base of the pyramid structure is either the length, width, or diagonal of the regular quadrilateral if the orthogonal projection pattern of the base surface of the pyramid structure onto the second surface 102 is a regular quadrilateral. Furthermore, the pyramid structures mentioned here include the first pyramids 131a, the second pyramids 111a, and a third pyramid described below.

[0056] In practical applications, the orthogonal projection pattern of the base of the pyramidal structure on the second surface can also be an irregular polygon. In this case, the length, width, or diagonal of the orthogonal projection pattern of the base of the pyramidal structure on the second surface is not absolute but is artificially defined to characterize the base of the pyramidal structure. For example, if the orthogonal projection pattern of the base of the pyramidal structure on the second surface is an irregular quadrilateral, the length of the base of the pyramidal structure can be defined as the side length of the longest side of the irregular quadrilateral, the width of the base of the pyramidal structure as the side length of the shortest side of the irregular quadrilateral, and the diagonal of the base of the pyramidal structure as the length of the longest diagonal of the irregular quadrilateral.It is understood that the above is only an exemplary description and can be flexibly defined in practice according to actual requirements. Furthermore, the orthogonal projection pattern of the base of the pyramidal structure onto the second surface can be not only an irregular quadrilateral, but also other irregular polygons, a circle, or an irregular, circle-like shape. In this case, the base of the pyramidal structure is obtained by selecting several different regions with a specific area at the base of the pyramidal structure. These regions with a specific area can be flexibly defined according to actual requirements in order to calculate average values ​​of the lengths, widths, diagonals, or diameters of the several different regions with a specific area.

[0057] In some embodiments, such as in Fig. 2 or Fig. 3. The heights of the first pyramid 131a and the second pyramid 111a can range from 1.5 µm to 2.5 µm and may be, for example, 1.6 µm, 1.7 µm, 1.8 µm, 1.9 µm, 2 µm, 2.1 µm, 2.2 µm, 2.3 µm, or 2.4 µm, etc. It should be noted that while the range of values ​​for the heights of the first pyramid 131a and the second pyramid 111a may be the same, the actual values ​​of the heights of the first pyramid 131a and the second pyramid 111a may be either the same or different.

[0058] It should be noted that the height of the pyramid refers to the distance between the apex and the base of the pyramid in the second direction Y. The second direction Y is the direction in which the second surface 102 points towards the first surface 101; in other words, the second direction Y is the direction of the thickness of the substrate 100.

[0059] In some embodiments, such as in Fig. 2 or Fig. 3. The vertex angles of the first pyramid 131a and the second pyramid 111a can be in a range of 65° to 80° and may be, for example, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, or 79°, etc. In this way, it is advantageous to capture incident light more efficiently, for example, by means of a pyramid-shaped structure with a smaller vertex angle, so that light from a greater number of angles of incidence can be completely reflected into the first surface 101 to increase the total amount of light entering the first surface 101.

[0060] It should be noted that the angle formed by the two opposite edges of the pyramid can be considered the apex angle of the pyramid.

[0061] In some cases, such as in Fig. As shown in Figure 2, in the same groove 151 along the first direction X, a length of the bottom surface 131 is the first length L1 and a length of the smooth inclined surface 181 is the second length L2. The ratio of the second length L2 to the first length L1 is in the range of 0.001 to 0.005. It can be, for example, 0.0015, 0.002, 0.0025, 0.003, 0.0035, 0.004, or 0.0045, etc.

[0062] It should be noted that both the first region 111 and the second region 121 extend along a third direction. Therefore, the groove 151 can be considered an elongated trench extending along this third direction, with the bottom surface 131 and the smooth, sloping surface 181 having identical dimensions in this third direction. The surface areas of the bottom surface 131 and the smooth, sloping surface 181 depend primarily on their respective lengths in the first direction X. Thus, by designing the ratio of the second length L2 to the first length L1 in the range of 0.001 to 0.01, the surface area of ​​the groove 151 is mainly determined by the area of ​​the bottom surface 131.The design of the first pyramidal structures 131a contained on the base surface 131 with a greater height is advantageous in order to provide a larger surface area and more attachment points, so that the film layer subsequently applied to the surface of the groove 151 can be better attached and the surface of the groove 151 can be covered more uniformly, i.e., it is advantageous to allow the deposited film layer, such as a passivation layer, an inverse reduction layer or a transparent conductive layer, to cover the surface of the groove 151 more uniformly, which has a positive effect on the reduction of defects and pores in the film layer as well as on improving the quality and performance of the film layer.

[0063] In some cases, such as in Fig. As shown in Figure 2, the first length L1 of the soil surface 131 along the first direction X lies in the range of 200 µm to 800 µm. For example, the first length L1 can be 250 µm, 300 µm, 350 µm, 400 µm, 450 µm, 500 µm, 550 µm, 600 µm, 650 µm, 700 µm or 750 µm, etc.

[0064] In some cases, such as in Fig. As shown in Figure 2, the depth H3 of the groove 151 lies in the range of 2 µm to 4 µm along the second direction Y, which represents a thickness direction of the substrate 100. In this way, the depth of the groove 151 is no more than 4 µm, and it is a groove 151 with a relatively shallow depth.

[0065] On the one hand, the penetration depth of short-wavelength light is low, and the relatively shallow depth of the groove 151 is advantageous for improving the absorption and utilization rate for short-wavelength light. On the other hand, the relatively shallow depth of the groove 151 is advantageous for reducing the path length of the photogenerated charge carriers in the second region 121 migrating to the first region 111, and for reducing the recombination probability of the photogenerated charge carriers. This increases the open-circuit voltage of the photovoltaic cell and improves the collection efficiency of the electrode located in the first region 111 for the photogenerated charge carriers. Furthermore, the relatively shallow depth of the groove 151 is advantageous for improving the overall flatness of the first surface 101, which in turn is advantageous for subsequently forming a film layer of uniform thickness on the first surface 101.

[0066] It should be noted that along the second direction Y, the plane on which the vertices of most of the first pyramids 131a are located is taken as the first plane, and the plane on which the vertices of most of the third pyramids 111a are located is taken as the second plane. Along the second direction Y, the depth H3 of the groove 151 refers to a distance between the first plane and the second plane. Furthermore, the vertices of all the first pyramids 131a contained on the ground surface 131 may be located in different planes; however, more than half of the vertices of the first pyramids 131a lie almost in the same plane, which can serve as the first plane.The vertices of all third pyramids 111a contained in the first region 111 may lie in different planes, but more than half of the vertices of the third pyramids 111a lie almost in the same plane, which can serve as the second plane.

[0067] For example, the depth H3 of the groove 151 along the second direction Y can be 2.1 µm, 2.2 µm, 2.3 µm, 2.4 µm, 2.5 µm, 2.6 µm, 2.7 µm, 2.8 µm, 2.9 µm, 3 µm, 3.1 µm, 3.2 µm, 3.3 µm, 3.4 µm, 3.5 µm, 3.6 µm, 3.7 µm, 3.8 µm or 3.9 µm, etc.

[0068] In some cases, as in Fig. Figure 2 shows that the plane on which the bases of most of the second pyramids 111a contained in the first region 111 are arranged is taken as the third reference plane, and the plane on which the bases of most of the first pyramids 131a contained on the ground surface 131 are arranged is taken as the second reference plane. Based on this value, the distance H4 along the second direction Y between the third reference plane of the first region 111 and the second reference plane of the ground surface 131 lies in the range of 2.5 µm to 4.5 µm. For example, it can be 2.6 µm, 2.7 µm, 2.8 µm, 2.9 µm, 3 µm, 3.1 µm, 3.2 µm, 3.3 µm, 3.4 µm, 3.5 µm, 3.6 µm, 3.7 µm, 3.8 µm, 3.9 µm, 4 µm, 4.1 µm, 4.2 µm, 4.3 µm or 4.4 µm etc.

[0069] It should be noted that in the above-mentioned different embodiments in Fig. 2 the second reference plane of the ground surface 131 and the third reference plane of the first region 111 are shown by densely dotted lines.

[0070] Furthermore, the ground surface of the first pyramid 131a is a plane on which the base of the first pyramid 131a is arranged. The orthogonal projection pattern of the base of the first pyramid 131a on the substrate 100 can be a regular quadrilateral or an irregular polygon. It should be noted that the ground surfaces of all first pyramids 131a contained in the ground surface 131 may lie in different planes, but more than half of the first pyramids 131a have ground surfaces that lie almost in the same plane, which can serve as the reference plane of the ground surface 131.

[0071] The ground surface of the second pyramid 111a is a plane in which the base of the second pyramid 111a is located. The orthogonal projection pattern of the base of the second pyramid 111a on the substrate 100 can be a regular quadrilateral or an irregular polygon. It should be noted that the ground surfaces of all second pyramids 111a contained in the first region 111 may lie in different planes; however, more than half of the second pyramids 111a have ground surfaces that lie almost in the same plane, which can serve as the reference plane for the first region 111.

[0072] In some embodiments, such as in Fig. As shown in Figure 2, the angle of inclination γ of the smooth inclined surface 181 in the direction of the second region near the first region 111 lies in the range of 40° to 55°. For example, the angle of inclination γ can be 40.5°, 41°, 41.5°, 42°, 42.5°, 43°, 43.5°, 44°, 44.5°, 45°, 45.5°, 46°, 46.5°, 47°, 47.5°, 48°, 48.5°, 49°, 49.5°, 50°, 50.5°, 51°, 51.5°, 52°, 52.5°, 53°, 53.5°, 54°, or 54.5°, etc. It should be noted that the inclination angle γ of different smooth surfaces 181 inclined towards the first region 111 may either be identical or exhibit slight variations. However, the numerical range of the inclination angle γ for each smooth surface 181 inclined towards the first region 111 can be set in the range of 40° to 55°.

[0073] It should be noted that by designing the angle of inclination γ, the smooth portion of the slope 181 inclined towards the first region 111 can be designed with an angle of 40° to 55° to avoid excessive steepness of the smooth surface 181. As a transition region between the ground surface 131 and the first region 111, the smooth inclined surface 181 reduces abrupt differences in elevation between adjacent regions of the smooth inclined surface 181. In other words, with the second surface 102 as the reference plane, this design minimizes differences in elevation between adjacent regions along the first direction X across the smooth inclined surface 181, thus enabling a gradual morphological transition from the elevated first region 111 to the lower-lying ground surface 131 on the first surface 101.This smooth transition is advantageous for achieving a uniform layer thickness (e.g., passivation layers) on the first surface 101, thereby improving the passivation effectiveness.

[0074] Furthermore, if the inclination angle γ of the smooth surface 181 inclined towards the first region 111 is set to less than 40°, compared to an inclination angle γ of greater than or equal to 40°, the size of the transition region 122 in the first direction X is increased, while the area of ​​the smooth inclined surface 181 remains constant, and thus the number of first regions 111 that can be arranged on the entire first surface 101 is reduced. Therefore, it is advantageous to dimension the inclination angle γ of the smooth surface 181 inclined towards the first region 111 to a value of at least 40° to ensure that the smooth inclined surface 181 has a certain area, while simultaneously reducing the overall size of the smooth inclined surface 181 in the first direction X.the proportion of transition region 122 that is occupied by transition region 122 over the entire first surface 101 is reduced.

[0075] It should be noted that with regard to Fig. 2. The plane on which a large part of the ground surfaces of the first pyramids 131a contained in the ground surface 131 lies is used as the reference surface of the ground surface 131. Based on this, the angle of inclination γ of the smooth surface 181 inclined towards the first region 111 refers to an acute angle formed between the smooth inclined surface 181 and the reference plane of the ground surface 131.

[0076] In some embodiments, such as in Fig. 4 shown, shows Fig. 4 a schematic diagram showing a second partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure, wherein the photovoltaic cell further comprises a first protective layer 103 covering the bottom surface 131 and the smooth inclined surface 181.

[0077] It should be noted that with regard to Fig. 2, Fig. 3 to Fig. 4 On the one hand, the first protective layer 103 helps to protect the morphology of the first pyramids 131a, for example when other film layers are subsequently formed on the second regions 121 and structuring is carried out, wherein the first protective layer 103 can serve as an etching barrier to prevent damage to the first pyramids 131a and the smooth inclined surface 181 by the structuring process, thus advantageously ensuring that the second regions 121 have a relatively lower reflectivity.

[0078] On the other hand, the first protective layer 103 facilitates the improvement of the optical properties of the second regions 121 in order to further reduce the reflection loss of the second regions 121, for example to reduce the reflectivity of the entire photovoltaic cell on the surface of the second regions 121 and ultimately to improve the absorption and utilization rate of the second regions 121 for light, thereby increasing the photoelectric conversion efficiency of the photovoltaic cell.

[0079] In some cases, after the first protective layer 103 has been formed by an oxygen-free high-temperature process, the reflectivity of the entire surface of the photovoltaic cell located in the second region 121 can be reduced by approximately 0.1 to 0.3 compared to the initial value. In other cases, after the first protective layer 103 has been formed by an oxygen-containing high-temperature process, the reflectivity of the entire surface of the photovoltaic cell located in the second region 121 can be reduced by approximately 0.5 to 1 compared to the initial value. In still other cases, after the first protective layer 103 has been formed by an in-situ doping oxidation process, the reflectivity of the entire surface of the photovoltaic cell located in the second region 121 can be reduced by approximately 0.5 to 1 compared to the initial state.The oxygen-free high-temperature process, the oxygen-containing high-temperature process, and the in-situ doped oxidation process will be described in more detail later.

[0080] In some embodiments, such as in Fig. As shown in Figure 4, the first protective layer 103 can consist of a semiconductor material doped with a doping element, silicon oxide, phosphosilicate glass or borosilicate glass.

[0081] In some cases, the semiconductor material contained in the first protective layer 103 is an elemental semiconductor material. More precisely, the elemental semiconductor material consists of a single element. For example, it could be silicon or germanium. The elemental semiconductor material can be in a single-crystal state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state that exhibits both a single-crystal and an amorphous state is called a microcrystalline state). For example, silicon can be at least one of single-crystal silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In other cases, the semiconductor material contained in the first protective layer 103 is a compound semiconductor material.Common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallide, perovskite, cadmium telluride or copper indium selenide and other materials.

[0082] In some cases, the dopant element contained in the first protective layer 103 can be an N-type or a P-type dopant element. The N-type dopant element can be at least one of the elements in Group V, such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type dopant element can be at least one of the elements in Group III, such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0083] In some embodiments, the substrate 100 can consist of an elemental semiconductor material or a compound semiconductor material.

[0084] In some cases, substrate 100 can be an N-type semiconductor substrate doped with an N-type doping element. In some other cases, substrate 100 can be a P-type semiconductor substrate doped with a P-type doping element.

[0085] In some embodiments, such as in Fig. Figure 5, which is a schematic diagram showing a third partial sectional view of a photovoltaic cell provided in an embodiment of the present disclosure, further comprises: a tunneling layer 108 arranged on the second surface 102, a first doped semiconductor layer 105 doped with a first dopant and arranged remotely from the second surface 102, and a second doped semiconductor layer 106 doped with a second dopant and arranged on the first regions 111. The conductivity type of the first dopant differs from the conductivity type of the second dopant.The photovoltaic cell further comprises a first passivation layer 118, which is located on a side of the first doped semiconductor layer 105 away from the tunneling layer 108, a second passivation layer 128, which is located on a side of the second doped semiconductor layer 106 away from the substrate 100 and is arranged on the second regions 121, first electrodes 109, which are embedded in the first passivation layer 118 and are in ohmic contact with the first doped semiconductor layer 105, and second electrodes 119, which are embedded in the second passivation layer 128 and are in ohmic contact with the second doped semiconductor layer 106.

[0086] It should be noted that the second doped semiconductor layer 106, as a selective emitter structure on the first surface 101, helps to ensure that the second electrodes 119 based on the second doped semiconductor layer 106 have a good current collection efficiency, while at the same time preventing the second regions 121 from being covered by the second doped semiconductor layer 106, thus avoiding the parasitic absorption of the second doped semiconductor layer 106 for the light incident on the second regions 121 and improving the utilization of the first surface 101 for the incident light, thereby increasing the photoelectric conversion efficiency of the photovoltaic cell.

[0087] Furthermore, the tunneling layer 108 and the first doped semiconductor layer 105 together form a passivated contact structure. The tunneling layer 108 chemically passivates the second surface 102, saturates the free bonds of the second surface 102, reduces the defect density of the second surface 102, and reduces the recombination probability of charge carriers on the second surface 102. The first doped semiconductor layer 105 field-passivates the second surface 102, thereby reducing the concentration of minority charge carriers and thus the recombination probability of charge carriers on the second surface 102, thereby improving the photoelectric conversion efficiency of the photovoltaic cell.Furthermore, the first passivation layer 118 can further passivate the second surface 102 and serve as an optical optimization layer for the second surface 102 to improve the absorption and utilization rate of the second surface 102 for light. The second passivation layer 128 can passivate the first surface 101 to reduce the defect density of the first surface 101 and serve as an optical optimization layer for the first surface 101 to improve the absorption and utilization rate of the first surface 101 for light.

[0088] In some cases, the second doped semiconductor layer 106, doped with the second doping element, is formed in an initial state of the substrate 100. In other words, there is no obvious boundary line between the second doped semiconductor layer 106 and the substrate 100, which is located in the first region 111. Fig. 5. To simplify the description, different filling methods are used to represent the substrate 100 and the second doped semiconductor layer 106 in one drawing. On this basis, the smooth inclined surface 181 of the groove 151, which is formed by the substrate 100 arranged in the second region 121 and is recessed in the direction of the second surface 102, can be considered to be formed jointly by the second doped semiconductor layer 106 and the substrate 100 arranged in the first region 111.

[0089] In some cases, the tunneling layer 108 material may comprise at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or magnesium fluoride, and the first doped semiconductor layer 105 material may comprise at least one of amorphous silicon, polycrystalline silicon, or silicon carbide. Both the first doped semiconductor layer 105 and the substrate 100 may be doped with the first dopant.

[0090] In some cases, both the second passivation layer 128 and the first passivation layer 118 can have either a single-layer or a multi-layer structure. Furthermore, the materials of both the second passivation layer 128 and the first passivation layer 118 can comprise at least one of aluminum oxide, silicon oxide, silicon nitride, or silicon oxynitride.

[0091] In some cases, the substrate 100 can be an N-type semiconductor substrate doped with an N-type dopant, wherein the first dopant in the first doped semiconductor layer 105 is an N-type dopant and the second dopant in the second doped semiconductor layer 106 is a P-type dopant. In some other cases, the substrate 100 can be a P-type semiconductor substrate doped with a P-type dopant, wherein the first dopant in the first doped semiconductor layer 105 is a P-type dopant and the second dopant in the second doped semiconductor layer 106 is an N-type dopant.

[0092] In summary, to avoid the entire second region 121 having a pyramid-shaped surface, the transition region between the ground surface 131 and the first region 111 is designed as a smooth, sloping surface 181. On the one hand, a height difference between the ground surface 131 and the first region 111 is advantageous in order to utilize the smooth, sloping surface 181 to efficiently reflect the light not absorbed by the ground surface 131, so that the light is ultimately reflected to the first region 111 to be absorbed and utilized there. This is advantageous for achieving controlled light utilization and reducing the overall reflection loss of light at the first surface 101.On the other hand, light incident obliquely relative to the first direction X onto the second region 121 can change its angle through reflection at the smooth inclined surface 181 and is more likely to be received by the base surface 131, which is designed as the first structured surface with several first pyramids 131a, or by the first region 111, which is designed as the second structured surface with several second pyramids 111a. Then the first surface 101 as a whole can receive light at more angles of incidence, thus reducing light emission, which further reduces the reflection loss of light on the first surface 101 and improves the photoelectric conversion efficiency of the photovoltaic cell under low-light or oblique lighting conditions. Furthermore, it is advantageous to improve the overall flatness of the second region 121 with the help of the smooth inclined surface 181.If a film layer is subsequently formed on the first surface 101, the smooth inclined surface 181 allows the film layer to transition smoothly from the first region 111 to the bottom surface 131, which is advantageous for the formation of a film layer of uniform thickness on the first surface 101. The smooth inclined surface 181 can reduce the degree of stress concentration during film deposition and thus reduce the risk of film cracking or delamination. Furthermore, it is advantageous that the photogenerated charge carriers in the second region 121 migrate rapidly to the nearest first region 111 with the aid of the smooth inclined surface 181, thus reducing the lateral transfer distance of the photogenerated charge carriers and consequently reducing the recombination probability of the photogenerated charge carriers.Furthermore, it is advantageous to use the smooth inclined surface 181 as a channel for guiding the photogenerated charge carriers, thus avoiding the problem of local concentration of photogenerated charge carriers caused by the conventional structured surface. This improves the fill factor of the photovoltaic cell and increases its photoelectric conversion efficiency. Additionally, the groove 151 arranged in the second region 121 is advantageous for increasing the number of light reflections and / or scatterings in the second region 121 and for increasing the surface area of ​​the second region 121 for light absorption, thus further enhancing the light-trapping effect of the second region 121.

[0093] Another embodiment of the present disclosure further provides a method for manufacturing a photovoltaic cell, configured to form the photovoltaic cell provided in the preceding embodiments. The method for manufacturing the photovoltaic cell provided in another embodiment of the present disclosure with reference to the drawings is described in more detail below. Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. Figure 11 are schematic diagrams of partial cross-sectional structures corresponding to the individual steps of the method for manufacturing the photovoltaic cell provided in a further embodiment of the present disclosure. It should be noted that identical or corresponding parts as in the preceding embodiments are not described here in more detail.

[0094] With reference to Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 as well Fig. 1, Fig. 2 to Fig. 3. The process for manufacturing the photovoltaic cell may include at least the following steps.

[0095] S1: With reference to Fig. 6 shows Fig. 6 A schematic partial sectional view of an initial substrate provided in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure; an initial substrate 110 is provided, wherein the initial substrate 110 has an initial first surface 120 and an initial second surface 130, which are opposite each other. The initial first surface 120 has initial first regions 140 and initial second regions 150, which are arranged alternately along the first direction X.

[0096] It should be noted that the initial first surface 120 corresponds to the later formed first surface, the initial first regions 140 correspond to the first regions of the later formed first surface, the initial second regions 150 correspond to the second regions of the later formed first surface, and the initial second surface 130 corresponds to the later formed second surface.

[0097] S2: With reference to Fig. 6, Fig. 7 to Fig. 8 The initial second regions 150 are irradiated using a laser spot with a gradual change in energy to convert a section of the thickness of the initial substrate 110, which is arranged in the initial second regions 150, into a damage layer 104, and the change in energy of the laser spot in the direction from the center of the laser spot to the edge comprises successively at least a first stage I, a second stage II and a third stage III, wherein the energy of the laser spot in the first stage I is at a first preset value, the energy of the laser spot in the second stage II gradually increases from the first preset value to a second preset value and the energy of the laser spot in the third stage III gradually decreases from the second preset value to zero.In other words, in the direction from the center of the laser spot to the edge, the energy of the laser spot initially remains unchanged, then gradually increases and finally gradually decreases to zero.

[0098] It should be noted that Fig. 7 is a schematic diagram showing a partial cross-section of a damage layer formed in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 8 is a diagram corresponding to the energy gradient of a laser spot in a method for manufacturing a photovoltaic cell according to an embodiment of the present disclosure. Furthermore, the center of the laser spot is shown in Fig. 8 is assumed to be point 0.

[0099] S3: With reference to Fig. 7 and Fig. 1, Fig. 2 to Fig. 3 Each initial second region 150 is subjected to a first texturing process to remove at least the damage layer 104 and to form a groove 151 in the second region 121, wherein the remaining initial substrate 110 is the substrate 100, wherein the initial first region 140 is converted into the first region 111 of the substrate 100 and the initial second region 150 is converted into the second region 121 of the substrate 100, and wherein the substrate 100 has a ground surface 131 recessed towards the interior of the substrate 100, and a smooth inclined surface 181 connecting the ground surface 131 and the first region 111, wherein the smooth inclined surface 181 is inclined towards the first region 111 and the ground surface 131 and the smooth inclined surface 181 enclose the groove 151.

[0100] The ground surface 131 is formed as the first structured surface, comprising several first pyramids 131a, and the region 111 is formed as the second structured surface, comprising several second pyramids 111a.

[0101] It should be noted that during the process of irradiating the initial second region 150 with the laser spot during gradual energy changes in step S2, only the damage layer 104 is formed in the initial second region 150, and no stepped structure with a height difference between the initial first region 140 and the initial second region 150 is created. Based on this, in step S3, the initial second region 150 is transformed into the second region 121 with the groove 151 by means of the difference in the etch rates of the damage layer 104 in the initial second region 150 and in the initial first region 140 during the first texturing treatment.

[0102] Furthermore, this is based on the design in step S2, according to which, along the direction from the center to the edge of the laser spot, the energy of the laser spot initially remains unchanged, then gradually increases, and finally gradually decreases to zero. This is advantageous for the formation of the damage layer 104 with varying thicknesses in different regions in step S2. Generally speaking, the section of the initial substrate 110 irradiated by the higher-energy section of the laser spot exhibits a greater degree of laser-induced damage, and the resulting damage layer 104 has a greater thickness or its interior is more completely destroyed. For example, in a direction from the center of the initial second region 150 to the initial first region 140, the thickness of the damage layer 104 initially remains unchanged, then gradually increases, and finally gradually decreases to zero.Based on this, in step S3, the etch rates of different regions of the damage layer 104 differ during the first texturing treatment, and the times required for the first texturing treatment to remove damage layer 104 of varying thicknesses also differ. Therefore, the first texturing treatment exposes the initial substrate 110, which is covered by different sections of the damage layer 104, at different times in order to achieve texturing only on the remaining initial substrate 110. Consequently, it is advantageous to form the groove 151, which is jointly surrounded by the bottom surface 131 and the smooth inclined surface 181, and to form the bottom surface, which is intended as the first textured surface 131 and comprises several first pyramids 131a.

[0103] In other words, through the interaction of the irradiation of the initial second region 150 with the laser spot, the energy of which gradually changes in step S2, and the first texturing treatment in step S3, the inflection points of the etch rates of different regions of the film layer, which is jointly formed from the damaged layer 104 and the remaining initial substrate 110, differ during the first texturing treatment along the direction from the center of the initial second region 150 to the initial first region 140. Furthermore, the average etch rate of the first texturing treatment at different regions of the film layer, which jointly comprises the damaged layer 104 and the remaining initial substrate 110, is additionally designed to change gradually, for example, initially remaining unchanged and then gradually decreasing to zero, thereby favoring the eventual formation of the smooth inclined surface 181.

[0104] In some embodiments, such as in Fig. 8 and Fig. Figure 2 shows that the position with the maximum energy of the laser spot, i.e., the second preset value, irradiates the ground surface 131 of the groove 151 and irradiates the region of the ground surface 131 near the smooth inclined surface 181. It should be noted that the energy of a single laser spot reaches the second preset value in two different regions, and the two second preset values ​​each irradiate the regions of the ground surface 131 near two different smooth inclined surfaces 181.

[0105] In some cases, along the first direction X, an irradiation position of the ground surface 131 corresponding to the second preset value and a junction of the smooth inclined surface 181 and the ground surface 131 are spaced apart by a preset distance D, and the ratio of the preset distance D to the first length L1 of the ground surface 131 is in the range of 0.0025 to 0.05. For example, the ratio can be 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, or 0.045, etc.

[0106] It should be noted that the first length L1 of the smooth inclined surface 181 is formed by several laser lines that open the film, and that the surface of the groove 151 is primarily determined by the first length L1 of the ground surface 131. The range of values ​​for the first length L1 is relatively large. Based on this value, the range of values ​​for the ratio of the preset distance D to the first length L1 of the ground surface 131 is also relatively large. However, compared to the first length L1 of the ground surface 131, the preset distance D between the irradiation position of the ground surface 131, corresponding to the second preset value, and the junction of the smooth inclined surface 181 and the ground surface 131 is relatively small. In other words, the position irradiated by the inflection point of the laser spot's energy decay is very close to the ultimately formed smooth inclined surface 181.

[0107] For example, the preset distance D between the irradiation position of the ground surface 131, which corresponds to the second preset value, and the junction of the smooth inclined surface 181 and the ground surface 131 is in the range of 5 µm to 10 µm. For example, the preset distance D can be 5.2 µm, 5.5 µm, 5.8 µm, 6 µm, 6.3 µm, 6.5 µm, 6.6 µm, 6.8 µm, 7 µm, 7.3 µm, 7.5 µm, 7.7 µm, 8 µm, 8.2 µm, 8.5 µm, 8.8 µm, 9 µm, 9.3 µm or 9.5 µm etc.

[0108] In some examples, the overall size of the laser spot ranges from 50 µm to 200 µm. In other words, the diameter of the laser spot ranges from 50 µm to 200 µm. For example, the diameter of the laser spot can be 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 110 µm, 120 µm, 130 µm, 140 µm, 150 µm, 160 µm, 170 µm, 180 µm, or 190 µm, etc.

[0109] In some embodiments, which relate to Fig. 7 and Fig. Referring to 8, a single laser spot at the center is divided into two symmetrical sections. Along the first direction X lies the width of the irradiation area of ​​one of the two sections of the laser spot, corresponding to the first stage I on the initial second region 150, for example in the range of 20 µm to 50 µm, and can be 21 µm, 22 µm, 23 µm, 24 µm, 25 µm, 26 µm, 27 µm, 28 µm, 29 µm, 30 µm, 31 µm, 32 µm, 33 µm, 34 µm, 35 µm, 36 µm, 37 µm, 38 µm, 39 µm, 40 µm, 41 µm, 42 µm, 43 The width of the irradiation area of ​​one of the two sections of the laser spot corresponding to the second stage II on the initial region 150 is, for example, in the range of 2 µm to 5 µm, and can be 2.2 µm, 2.5 µm, 2.6 µm, 3 µm, 3.2 µm, 3.5 µm, 3.8 µm, 4 µm, 4.2 µm, 4.5 µm, or 4.8 µm, etc.The width of the irradiation area of ​​one of the two sections of the laser spot, corresponding to the third stage III on the initial second region 150, is, for example, in the range of 5 µm to 10 µm, and can be 5.2 µm, 5.5 µm, 5.6 µm, 5.8 µm, 6 µm, 6.2 µm, 6.5 µm, 6.6 µm, 7 µm, 7.2 µm, 7.5 µm, 7.8 µm, 8 µm, 8.2 µm, 8.5 µm, 8.8 µm, 9 µm, 9.2 µm, 9.5 µm or 9.8 µm, etc.

[0110] It should be noted that the width of the irradiation area of ​​the laser spot corresponding to the second stage II on the initial second region 150 is in the range between 2 µm and 5 µm, and the width of the irradiation area of ​​the laser spot corresponding to the third stage III on the initial second region 150 is designed to be in the range of 5 µm to 10 µm by increasing the irradiation area of ​​the laser spots corresponding to the second stage II on the initial second region 150, which is advantageous for controlling the relatively low degree of damage within the damage layer 104, which corresponds to the finally formed smooth inclined surface 181, in order to reduce the degree of etching of the damage layer 104 and the initial substrate 110, which correspond to the inclined surface 141 finally formed during the first texturing treatment.as well as for promoting the formation of the smooth inclined surface 181 after the first texturing treatment.

[0111] In some embodiments, such as in Fig. As shown in Figure 8, the energy of the laser spot is the irradiance of the laser spot. Along the direction from the center to the edge of the laser spot, the irradiance of the laser spot is increased by 0.016 J / mm² in the second stage II. 2 per 1 µm distance to 0.095 J / mm 2 in the second stage II, the irradiance of the laser spot is increased by 0.01 J / mm² in the third stage III. 2 per 1 µm distance to 0.04 J / mm 2 reduced.

[0112] It should be noted that it is advantageous to set the growth rate of the laser spot irradiance in the second stage II to be greater than the decrease rate of the laser spot irradiance in the third stage III in order to ultimately form a ground surface 131 with a greater length in the first direction X and a smooth, less steeply inclined surface 181. Furthermore, it is advantageous to set the growth rate of the laser spot irradiance moderately in the second stage II so that the first texturing treatment forms the smooth inclined surface 181 and creates the first pyramidal structures 131a on the ground surface 131.

[0113] In some examples, the radiation intensity of the laser spot along the direction from the center to the edge of the laser spot can be increased by 0.017 J / mm² per 1 µm distance in the second stage II. 2 , 0.02 J / mm 2 , 0.025 J / mm 2 , 0.03 J / mm 2 , 0.035 J / mm 2, 0.04 J / mm 2 , 0.045 J / mm 2 , 0.05 J / mm 2 , 0.055 J / mm 2 , 0.06 J / mm 2 , 0.065 J / mm 2 , 0.07 J / mm 2 , 0.075 J / mm 2 , 0.08 J / mm 2 , 0.085 J / mm 2 or 0.09 J / mm 2 etc. increase.

[0114] In some examples, the irradiance of the laser spot along the direction from the center to the edge of the laser spot can be increased by 0.011 J / mm² per 1 µm distance in the third stage III. 2 , 0.012 J / mm 2 , 0.013 J / mm 2 , 0.014 J / mm 2 , 0.015 J / mm 2 , 0.016 J / mm 2 , 0.017 J / mm 2 , 0.018 J / mm 2 , 0.019 J / mm 2 , 0.02 J / mm 2 , 0.021 J / mm 2 , 0.022 J / mm 2 , 0.023 J / mm 2 , 0.024 J / mm 2 , 0.025 J / mm 2 , 0.026 J / mm², 0.027 J / mm² 2 , 0.028 J / mm 2 , 0.029 J / mm 2 , 0.03 J / mm 2 , 0.031 J / mm 2, 0.032 J / mm 2 , 0.033 J / mm 2 , 0.034 J / mm 2 , 0.035 J / mm 2 , 0.036 J / mm 2 , 0.037 J / mm 2 , 0.038 J / mm 2 or 0.039 J / mm 2 etc. decrease.

[0115] It should be noted that irradiance indicates the amount of radiant energy that strikes the surface irradiated by the radiant energy per unit area and per unit time, i.e., the radiant flux density on the irradiated surface.

[0116] In some embodiments, such as in Fig. As shown in Figure 8, the first preset value can be in the range of 0.01 J / mm² to 0.02 J / mm² and can, for example, be 0.011 J / mm². 2 , 0.012 J / mm2, 0.013 J / mm2, 0.014 J / mm, 0.015 J / mm 2 , 0.016 J / mm 2 , 0.017 J / mm 2 , 0.018 J / mm 2 or 0.019 J / mm 2 etc. The second preset value can range from 0.1 J / mm² to 0. 2J / mm2 and can, for example, be 0.11 J / mm 2 , 0.12 J / mm 2 , 0.13 J / mm 2 , 0.14 J / mm 2 , 0.15 J / mm 2 , 0.16 J / mm², 0.17 J / mm² 2 , 0.18 J / mm 2 or 0.19 J / mm 2 etc.

[0117] In some embodiments, such as in Fig. 7 and Fig. 1, Fig. 2 to Fig. As shown in Figure 3, the first structuring treatment uses a first etching solution containing potassium hydroxide and water, wherein the ratio of potassium hydroxide to water is in the range of 0.002:1 to 0.01:1 and may be, for example, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008 or 0.009 etc.

[0118] In some embodiments, the treatment duration of the first texturing treatment is in the range of 100 s to 200 s and can be, for example, 105 s, 110 s, 115 s, 120 s, 125 s, 130 s, 135 s, 140 s, 145 s, 150 s, 155 s, 160 s, 165 s, 170 s, 175 s, 180 s, 185 s, 190 s or 195 s, etc.It should be noted that the irradiation area of ​​the laser spot, corresponding to the second stage II on the initial region 150, is increased to control a higher degree of damage within the damage layer 104, which corresponds to the finally formed smooth inclined surface 181, to improve the etching degree of the first texturing treatment on the damage layer 104, which corresponds to the finally formed slope 141, and on the initial substrate 110, as well as to shorten the process duration of the first texturing treatment so that the smooth inclined surface 181 can be formed in a short time and the depth of the formed groove 151 can be reduced.

[0119] In some embodiments, the process temperature of the first texturing treatment is in the range of 65 °C to 75 °C and can be, for example, 66 °C, 67 °C, 68 °C, 69 °C, 70 °C, 71 °C, 72 °C, 73 °C or 74 °C, etc.

[0120] In some embodiments, the method for manufacturing the photovoltaic cell includes, with reference to Fig. 1, Fig. 4, Fig. 9 and Fig. 10 furthermore: as in Fig. 1 and Fig. Figure 4 shows the application of a high-temperature treatment or a high-temperature doping treatment to the grooves 151 to form a first protective layer 103 covering the bottom surface 131 and the smooth inclined surface 181, as in Fig. 4 and Fig. Figure 9 shows the formation of a first doped semiconductor layer 105 on the second surface 102, wherein the first doped semiconductor layer 105 is also arranged on a section of the first surface 101, and as in on Fig. 9 and Fig. Figure 10 shows the execution of an etching process on the first doped semiconductor layer 105, which is arranged on the first surface 101, wherein the first protective layer 103 serves as an etching barrier.

[0121] Fig. Figure 9 is a schematic representation showing a partial sectional view of the formation of a first doped semiconductor layer on a substrate. Fig. The structure shown in section 4 is shown. Fig. Figure 10 is a schematic representation showing a partial sectional view of the execution of an etching process on a [material / structure] in [location] Fig. The structure shown in 9 is shown.

[0122] It should be noted that during the formation of the first doped semiconductor layer 105 on the second surface 102, a winding-cladding phenomenon can occur, so that the first doped semiconductor layer 105 can also form on some regions of the first surface 101. Subsequently, an etching process must be carried out on the first doped semiconductor layer 105 located on the first surface 101. During the etching process, the first protective layer 103 can serve as an etching barrier to prevent damage to the surface of the first pyramidal structures 131a and the smooth inclined surfaces 181 by the etching process, which contributes to the second region 121 having a relatively low reflectivity. Furthermore, the first protective layer 103 helps to improve the optical performance of the second region 121 in order to further reduce the reflection loss of the second region 121.For example, the first protective layer 103 can reduce the reflectivity of the entire surface of the photovoltaic cell arranged in the second regions 121 in order to improve the absorption and utilization rate of the second region 121 of the first surface 101 for light and thereby increase the photoelectric conversion efficiency of the photovoltaic cell.

[0123] In some cases, the process temperature of the high-temperature treatment or high-temperature doping treatment is in the range of 900 °C to 1050 °C, and the treatment duration is 2000 s to 5000 s.

[0124] In some examples, the process temperature of the high-temperature treatment or high-temperature doping treatment can be 910 °C, 920 °C, 930 °C, 940 °C, 950 °C, 960 °C, 970 °C, 980 °C, 990 °C, 1000 °C, 1010 °C, 1020 °C, 1030 °C or 1040 °C, etc.

[0125] In some examples, the treatment duration of the high-temperature treatment or the high-temperature doping treatment can be 2100 s, 2200 s, 2300 s, 2400 s, 2500 s, 2600 s, 2700 s, 2800 s, 2900 s, 3000 s, 3100 s, 3200 s, 3300 s, 3400 s, 3500 s, 3600 s, 3700 s, 3800 s, 3900 s, 4000 s, 4100 s, 4200 s, 4300 s, 4400 s, 4500 s, 4600 s, 4700 s, 4800 s or 4900 s etc.

[0126] In some cases, the high-temperature treatment can be an oxygen-free high-temperature process. By directly performing a high-temperature treatment at the groove 151, a section of the substrate 100 corresponding to the groove 151 can be transformed into the first protective layer 103. In some examples, the substrate 100 is a semiconductor material doped with a dopant. Based on the oxygen-free high-temperature process, it is advantageous to increase the concentration of the dopant in a section of the substrate 100 near the groove 151, thereby forming the first protective layer 103 with a different dopant concentration than the dopant concentration in the rest of the substrate 100. The material of the first protective layer 103 is also a semiconductor material containing a dopant.It should be noted that after the formation of the first protective layer 103 by the oxygen-free high-temperature process, the reflectivity of the entire surface of the photovoltaic cell, which is located in the second region 121, can be reduced by about 0.1 to 0.3 compared to the initial state.

[0127] In some other cases, the high-temperature treatment can be an oxygen-containing high-temperature process. When a high-temperature treatment is performed on the groove 151, an oxidation treatment is also performed on the groove 151, whereby a section of the thickness of the substrate 100 corresponding to the groove 151 can be oxidized to form the first protective layer 103. In some examples, the substrate 100 can contain a silicon material, and the first protective layer 103, which contains silicon oxide, is formed based on the oxygen-containing high-temperature process. It should be noted that after the formation of the first protective layer 103 by the oxygen-containing high-temperature process, the reflectivity of the entire surface of the photovoltaic cell arranged in the second regions 121 can be reduced by about 0.5 to 1 compared to the initial state.

[0128] In other cases, the high-temperature doping treatment can be an in-situ doping oxidation process. When a high-temperature treatment is performed on the groove 151, a doping treatment and an oxidation treatment are also carried out on the groove 151, such that a section of the thickness of the substrate 100 corresponding to the groove 151 is converted into the first protective layer 103, and the first protective layer 103 contains an oxidized material doped with a dopant. In some embodiments, the substrate 100 can comprise a silicon material, and the first protective layer 103, which contains phosphosilicate glass or borosilicate glass, is formed based on the in-situ doping oxidation process.

[0129] It should be noted that after the formation of the first protective layer 103 by the source-pass high-temperature process, the reflectivity of the entire surface of the photovoltaic cell located in the second regions 121 can be reduced by approximately 0.5 to 1 compared to the initial state. Furthermore, phosphosilicate glass or borosilicate glass are two examples of the first protective layer 103 formed based on the in-situ doping oxidation process. In practical applications, the doping source provided in the in-situ doping oxidation process can include other elements of group V or other elements of group III.

[0130] In other embodiments, no additional layer may be formed when performing the high-temperature treatment on the groove 151, and the high temperature provided by the high-temperature treatment merely repairs the laser damage to reduce the defect density on the surface of the groove 151, thereby reducing the center of charge carrier recombination at the groove 151 and improving the photovoltaic conversion efficiency of the photovoltaic cell.

[0131] In some cases, during the formation of the first doped semiconductor layer 105, a first dielectric layer (not shown in the drawings) is formed on a side of the first doped semiconductor layer 105 facing away from the second surface 102. For example, the substrate 100 is an N-type semiconductor substrate, the first doped semiconductor layer 105 is polysilicon doped with N-type dopants, and the material of the first dielectric layer can be phosphor silicon glass.

[0132] Based on this, the process of carrying out the etching process on the first doped semiconductor layer 105 arranged on the first surface 101 can include: removing the first dielectric layer arranged on the first surface 101 using a chain hydrofluoric acid process and removing the first doped semiconductor layer 105 not covered by the first dielectric layer using an alkaline polishing process, so that the first doped semiconductor layer 105 arranged on the first surface 101 is preserved.

[0133] In some cases, such as in Fig. As shown in Figure 5, the fabrication process prior to the formation of the first doped semiconductor layer 105 can further comprise: forming a tunneling layer 108 on the second surface 102. Subsequently, the first doped semiconductor layer 105 is formed on a side of the tunneling layer 108 that is remote from the substrate 100. It should be noted that there is no restriction regarding the method for forming the tunneling layer 108 in the fabrication process.

[0134] In some embodiments, such as in Fig. 6 and Fig. As shown in Figure 11, the method for producing the photovoltaic cell after providing the initial substrate 110 and before irradiating the initial second surface 150 with the laser spot with gradual energy change may further comprise: as in Fig. 6 and Fig. Figure 11 shows the application of a second texturing treatment to the initial first surface 120, such that the initial first surface 120 has several second pyramids 111a, and what next in Fig. Figure 11 shows the performance of a doping treatment on the initial first surface 120 to convert a section of the thickness of the initial substrate 110 into the second doped semiconductor layer 106, and the formation of a second protective layer 107 on a side of the second doped semiconductor layer 106 that is away from the initial substrate 110. As in Fig. 11 and Fig. As shown in Figure 2, when the first texturing treatment is carried out on the initial second region 150, the second doped semiconductor layer 106 arranged in the initial first regions 140 is preserved by the second protective layer 107 as an etch barrier layer, and the initial first regions 140 are provided as a second textured surface with several second pyramids 111a.

[0135] Fig. Figure 11 is a schematic diagram showing a partial sectional view of the formation of a second doped semiconductor layer and a second protective layer on an initial substrate in a method for producing a photovoltaic cell according to a further embodiment of the present disclosure.

[0136] It should be noted that the initial first surface 120 has several second pyramids 111a, which is advantageous for the subsequent formation of the first region 111 as a second structured surface with several second pyramids 111a. Furthermore, different structuring methods are used to form the initial first surface 120 with several second pyramids 111a and the grooves 151.

[0137] As also in Fig. 11 and Fig. As shown in Figure 7, during the process of irradiating the initial second region 150 with the laser spot, with gradual energy change in step S2, both the second protective layer 107 and the second doped semiconductor layer 106, which are arranged on the initial second region 150, are transformed into the damage layer 104. As shown in Fig. 11 and Fig. As shown in Figure 2, the second protective layer 107, which is arranged on the initial first region 140 that is not irradiated by the laser spot, can be used in step S3 as an etch barrier layer to ensure that only the first regions 111 remain as the second structured surface with multiple second pyramids 111a. As shown in Fig. As shown in Figure 5, the remaining second doped semiconductor layer 106 is arranged only on the first regions 111 in order to be used as a selective emitter structure on the first surface 101, which is advantageous to reduce the contact resistance between the subsequently formed second electrodes and the second doped semiconductor layer 106 and to reduce the recombination probability of charge carriers in other regions of the first surface 101, thus improving the photoelectric conversion efficiency of the finally formed photovoltaic cell.

[0138] In one example, the substrate 100 is an N-type semiconductor substrate, the second doped semiconductor layer 106 is a semiconductor material doped with a P-type doping element, such as a boron diffusion layer, and the material of the second protective layer 107 can be borosilicate glass.

[0139] It should be noted that the dimensional ratio between the first pyramid 131a and the second pyramid 111a is the same as in the preceding embodiments and is not repeated here.

[0140] In some cases, such as in Fig. 9 and Fig. As shown in Figure 10, after the alkaline polishing process, which serves to remove the first doped semiconductor layer 105 that is not covered by the first dielectric layer in order to obtain the first doped semiconductor layer 105 arranged on the second surface 101, the manufacturing process may further comprise: as shown in Fig. 11 and Fig. Figure 2 shows the removal of the remaining second protective layer 107, which is arranged on the initial first regions 140, using the acid cleaning process. It should be noted that by controlling the process parameters of the acid cleaning process, such as the process duration, the second protective layer 107 is removed by the acid cleaning process and the first protective layer 103 is retained, or both the second protective layer 107 and the first protective layer 103 are removed by the acid cleaning process.

[0141] In some cases, such as in Fig. As shown in Figure 5, the manufacturing process after forming the first doped semiconductor layer 105 and the second doped semiconductor layer 106 can further comprise: forming a first passivation layer 118 located on a side of the first doped semiconductor layer 105 away from the tunneling layer 108, forming a second passivation layer 128 located on a side of the second doped semiconductor layer 106 away from the substrate 100 and on the second regions 121, forming first electrodes 109 embedded in the first passivation layer 118 and in ohmic contact with the first doped semiconductor layer 105, and forming second electrodes 119 embedded in the second passivation layer 128 and in ohmic contact with the second doped semiconductor layer 106.

[0142] For example, the first passivation layer 118 and the second passivation layer 128 can be formed using an atomic layer deposition process and / or a plasma-enhanced chemical vapor deposition process. It should be noted that the second passivation layer 128, which is located on the first surface 101, and the first passivation layer 118 on the second surface 102 can be formed simultaneously.

[0143] In some embodiments, the steps for forming the first electrodes 109 may include: printing a metal paste onto the surface of a section of the first passivation layer 118, which is separated from the second surface 102, using a screen-printing process, and performing a sintering process on the metal paste. In some embodiments, the metal paste contains highly corrosive materials, such as glass. Thus, during the sintering process, the corrosive components can corrode at least the first passivation layer 118, allowing the metal paste to penetrate from the first passivation layer 118 into the first doped semiconductor layer 105, thereby forming the first electrodes 109. It should be noted that the steps for forming the second electrodes 119 are similar to those for forming the first electrode 109, and reference can be made to the above description of the steps for forming the first electrodes 109.

[0144] For example, the metal paste may contain at least one of silver, aluminum, copper, tin, gold, lead or nickel.

[0145] It should be noted that there is no restriction regarding the formation process of the first passivation layer 118, the second passivation layer 128, the first electrodes 109 and the second electrodes 119 in the manufacturing process provided in the embodiment of the present disclosure and different formation processes can be selected depending on the requirements in practical application.

[0146] In summary, based on the sequence described in step S2, in which the energy of the laser spot initially remains unchanged along the direction from the center to the edge, then gradually increases, and finally gradually decreases to zero, the formation of the damage layer 104 with varying thicknesses in different regions or with varying degrees of internal destruction is favored in step S2. Consequently, in step S3, the time required for the first texturing treatment to remove the varying thicknesses of the damage layer 104 varies. This is because the first texturing treatment exposes the initial substrate 110, which is covered by different sections of the damage layer 104, at different times, thus ensuring that the texturing treatment is performed on some regions of the remaining initial substrate 110.Thus, it is advantageous to form the groove 151, which is jointly enclosed by the bottom surface 131 and the smooth inclined surface 181, and the bottom surface 131 is formed as the first texturing surface, which includes several first pyramids 131a.

[0147] Another embodiment of the present disclosure further provides a photovoltaic module configured to convert received light energy into electrical energy. The photovoltaic module provided in another embodiment of the present disclosure is described in more detail with reference to the accompanying drawings. It should be noted that identical or corresponding parts as in the preceding embodiments are not described again here.

[0148] As in Fig. 1, Fig. 2, Fig. 3 to Fig. 4 as well as in Fig. 12 and Fig. As shown in Figure 13, the photovoltaic module comprises: at least one cell string, each formed by connecting several photovoltaic cells 40 provided in the embodiments described above, or by connecting several photovoltaic cells 40 formed by the photovoltaic cell manufacturing method provided in the embodiments described above; at least one encapsulation adhesive film 41 configured to cover a surface of the at least one cell string; and at least one cover plate 42 configured to cover a surface of the at least one encapsulation adhesive film 41 located away from the at least one cell string. The photovoltaic cells 40 are electrically connected in the form of a whole layer or multiple layers to form the at least one cell string, and the at least one cell string is electrically connected in series and / or parallel.

[0149] Fig. Figure 12 is a schematic representation showing a perspective partial view of a photovoltaic module according to a further embodiment of the present disclosure. Fig. Figure 13 is a schematic representation showing a cross-sectional view of the photovoltaic module along line MM1 in Fig. 12 shows.

[0150] In some embodiments, the photovoltaic cell 40 comprises, among other things, one or any combination of a PERC cell (Passivated Emitter Rear Cell), an IBC cell (Interdigitated Back Contact), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Heterojunction Technology), a thin-film solar cell, and a tandem cell. The thin-film solar cell includes, but is not limited to, a perovskite thin-film solar cell, a copper indium gallium selenide thin-film solar cell, a gallium arsenide thin-film solar cell, and a cadmium sulfide thin-film solar cell. The tandem cell includes, but is not limited to, 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.

[0151] In some embodiments, the photovoltaic cell 40 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component composite solar cell. More specifically, the multi-component composite solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium gallium selenide solar cell, or a perovskite solar cell. Furthermore, the photovoltaic cell 40 can be a whole cell or a sectional cell. A sectional cell is a cell formed by cutting a complete whole cell using a cutting process.

[0152] In some embodiments, such as in Fig. 13, several cell strands can be electrically connected via a conductive strip 402. Fig. Figure 13 shows only one positional relationship between photovoltaic cells, i.e., the electrodes of the same polarity of the photovoltaic cells are arranged in the same direction, or in other words, the electrodes with positive polarity of each photovoltaic cell are all arranged on the same side, so that the conductive strip connects the opposite sides of any two adjacent photovoltaic cells. In some embodiments, the photovoltaic cells can also be arranged such that the electrodes with opposite polarities point towards the same side, i.e., the electrodes of several adjacent photovoltaic cells are arranged sequentially in the order of first polarity, second polarity, and first polarity, with the conductive strip connecting two adjacent photovoltaic cells on the same side.

[0153] In some embodiments, there is no space between the photovoltaic cells, i.e., the adjacent photovoltaic cells overlap each other.

[0154] In some embodiments, the at least one encapsulation adhesive film 41 comprises a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers either the front or the back of the photovoltaic cell 40, and the second encapsulation layer covers the opposite side of the photovoltaic cell 40. More precisely, at least one of the first encapsulation layer and the second encapsulation layer can be an organic encapsulation adhesive film, such as a polyvinyl butyral (PVB) adhesive film, an ethylene vinyl acetate (EVA) adhesive film, a polyolefin elastomer (POE) adhesive film, or a polyethylene terephthalate (PET) adhesive film, or at least one of the first and second encapsulation layers can also be an adhesive film such as an EP adhesive film, an EPE adhesive film, or a PVP adhesive film.EP adhesive film refers to a co-extruded adhesive film consisting of an EVA adhesive film and a POE adhesive film layered on top of each other. EPE adhesive film refers to a co-extruded adhesive film formed using an EVA adhesive film, a POE adhesive film, and another EVA adhesive film layered sequentially. PVP adhesive film refers to a co-extruded adhesive film formed by layering a POE adhesive film, an EVA adhesive film, and another POE adhesive film. The manufacturing process for co-extruded adhesive films can involve extruding one or more raw materials sequentially onto an already manufactured adhesive film during processing, or bonding together previously manufactured adhesive films of different types.

[0155] In some cases, a separation boundary exists between the first and second encapsulation layers before lamination. After the lamination process, once the photovoltaic module is formed, the concepts of the first and second encapsulation layers no longer exist; that is, the first and second encapsulation layers have merged to form the entire encapsulation adhesive film 41.

[0156] In some embodiments, the at least one cover plate 42 can be a glass cover plate, a plastic cover plate, or any other cover plate with a translucent function. More precisely, the surface of the cover plate 42 facing the encapsulation adhesive film 41 can be a concave-convex surface or a structured surface with several protruding structures, thus increasing the utilization rate of the incident light. The at least one cover plate 42 comprises a first cover plate and a second cover plate. The first cover plate faces the first encapsulation layer, and the second cover plate faces the second encapsulation layer.

[0157] In some embodiments, the photovoltaic cell 40 can be a cell with busbars or a cell without busbars.

[0158] The embodiments of the present disclosure further provide a photovoltaic cell. In the photovoltaic cell described above, the morphology of the grooves and the first pyramidal structures contribute to enhancing the light-capturing effect in the second regions. On this basis, in order to ensure the enhancing effect of the grooves and the first pyramids on the light-capturing effect in the second regions, a first protective layer is designed to cover at least the first pyramids in order to protect the morphology of the first pyramids by means of the first protective layer.For example, if subsequent film layers are formed on the second regions and a structuring process is performed, the first protective layer can act as an etch barrier to prevent the structuring process from damaging the first pyramids. This avoids a reduction in the light absorption and utilization rate due to deformation of the first pyramids' surface, thus contributing to the second regions exhibiting a high light absorption and utilization rate. Furthermore, the first protective layer helps improve the optical performance of the second regions to further reduce reflection loss in these regions.For example, it can reduce the reflectivity of the entire surface of the photovoltaic cell located in the second region, thus ultimately improving the absorption and utilization rate of the second regions for light and thereby increasing the photoelectric conversion efficiency of the photovoltaic cell.

[0159] Fig. Figure 14 is a schematic representation showing a fourth partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. As in Fig. As shown in Figure 14, the photovoltaic cell comprises a substrate 100 having a first surface 101 and a second surface 102 facing each other. The first surface 101 has first regions 111 and second regions 121 arranged alternately in a first direction X. The substrate 100 has grooves 151 embedded in the second regions 121. Each groove 151 comprises a bottom surface 131, which is provided as a first structured surface with several first pyramids 131a. The photovoltaic cell includes a first protective layer 103 that covers at least the surfaces of the first pyramids 131a. The groove 151 embedded in the substrate 100 contributes to increasing the number of light reflections and / or scatterings in the second region 121 and increasing the surface area of ​​the second region 121 for light absorption, thereby facilitating the use of the groove 151 to increase the light-capturing effect of the second region 121 on light.Furthermore, the design of the floor surface 131 of the groove 151 as the first structured surface, which includes several first pyramids 131a, is also advantageous in order to improve the light-capturing effect of the floor surface 131 on light by means of the first pyramids 131a.

[0160] Based on this, to ensure the reinforcing effect of the groove 151 and the first pyramids 131a on the light-trapping effect of the second region, a first protective layer 103 is formed such that it covers at least the first pyramids 131a, thus protecting their morphology. If, for example, other film layers are subsequently formed on the second region 121 and a structuring process is carried out, the first protective layer 103 can serve as an etching barrier to prevent the structuring process from damaging the first pyramids 131a, thereby avoiding a reduction in the light absorption and utilization rate caused by deformation of the surface of the first pyramids 131a. This contributes to the second region 121 exhibiting a high light absorption and utilization rate.Furthermore, the first protective layer 103 contributes to improving the optical performance of the second region 121, thus further reducing the reflection loss in the second region 121. For example, the first protective layer 103 can reduce the reflectivity of the entire surface of the photovoltaic cell located in the second region 121, ultimately improving the absorption and utilization rate of light in region 121 and thereby increasing the photoelectric conversion efficiency of the photovoltaic cell.

[0161] In some cases, the first protective layer 103 can conformally cover the ground surface 131 and the slope 141, then the surface morphology of the section of the first protective layer 103 that is aligned with the ground surface 131 also has a structured morphology like the ground surface 131, and the surface morphology of the section of the first protective layer 103 that is aligned with the slope 141 also has a structured morphology like the slope 141.

[0162] In some cases, such as in Fig. As shown in Figure 14, the first protective layer 103 covers at least the surfaces of the first pyramids 131a, i.e., at least the surface morphology of a section of the first protective layer 103 that is oriented towards the ground surface 131 has a structured surface morphology similar to the structured surface morphology of the ground surface 131.

[0163] In some cases, the first protective layer 103 can cover the entire surface of the groove 151; that is, in addition to covering the surfaces of the first pyramids 131a, the first protective layer 103 also covers a transition surface in the groove 151 that connects a first region 111 with the bottom surface 131. The case in which the first protective layer 103 covers the entire surface of the groove 151 will be described in more detail later by way of example.

[0164] Some embodiments are in Fig. Figure 15, a schematic diagram showing a fifth partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure, further comprises: a tunneling layer 108 arranged on the second surface 102; a first doped semiconductor layer 105 doped with a first dopant and arranged remotely from the second surface 102; and a second doped semiconductor layer 106 doped with a second dopant and arranged on the first regions 111. The conductivity type of the first dopant differs from the conductivity type of the second dopant. The photovoltaic cell further comprises a first protective layer arranged on the second regions 121.The photovoltaic cell further comprises a first passivation layer 118, which is arranged on a side of the first doped semiconductor layer 105 away from the tunneling layer 108, a second passivation layer 128, which is arranged on a side of the second doped semiconductor layer 106 away from the substrate 100 and is located on the second regions 121, first electrodes 109, which are embedded in the first passivation layer 118 and are in ohmic contact with the first doped semiconductor layer 105, and second electrodes 119, which are embedded in the second passivation layer 128 and are in ohmic contact with the second doped semiconductor layer 106.

[0165] Furthermore, the morphology of the groove 151 and the first pyramid-shaped pyramids 131a contributes to enhancing the light-capturing effect in the second regions. Based on this, the first protective layer 103 is designed to cover at least the first pyramids 131a, thereby protecting their morphology and ensuring the enhancing effect of the grooves 151 and the first pyramids 131a on the light-capturing effect in the second regions.For example, when other film layers are subsequently formed on the second regions 121 and a structuring process is performed, the first protective layer 103 is used as an etch barrier to prevent the structuring process from damaging the first pyramids 131a. This avoids a reduction in the light absorption and utilization rate caused by deformation of the surface of the first pyramids 131a, thus contributing to the high light absorption and utilization rate of the second regions 121. Furthermore, the first protective layer 103 helps to improve the optical performance of the second regions 121, further reducing reflection loss in the second regions 121.For example, it can reduce the reflectivity of the entire surface of the photovoltaic cell arranged in the second regions 121, so that ultimately the absorption and utilization rate of the second regions 121 for light is improved and thereby the photoelectric conversion efficiency of the photovoltaic cell is increased.

[0166] The embodiments of the present disclosure further provide a photovoltaic cell, a method for manufacturing the photovoltaic cell, and a photovoltaic module. In the photovoltaic cell, the surface formed jointly by several inclined surfaces and the stepped surface connecting two adjacent inclined surfaces in the same groove is considered a slope. The groove with this slope can be viewed as a multi-layered stepped structure. On the one hand, it is advantageous to form a stepped light path in the groove so that the light incident on the groove is reflected multiple times between the inclined surfaces and the stepped surface and can finally be absorbed and utilized by the second region. On the other hand, the stepped light path is advantageous for widening and thus improving the absorption and utilization rate of the slope for long-wavelength light, such as infrared light.On the other hand, both the base area and the height of the secondary pyramids contained in the stepped surface are smaller compared to the primary pyramids contained in the ground surface. Firstly, it is advantageous to distribute the light incident on the slope more evenly with the help of the smaller secondary pyramids, thus improving the overall light absorption and utilization rate of the slope and reducing light leakage, thereby further reducing the reflection loss of light on the slope. Secondly, it is advantageous to enhance light scattering on the slope, thus improving the absorption rate of the slope for short-wavelength light, such as blue and ultraviolet light.In this way, the combined effect of several aspects achieves a multi-stage light-trapping effect macroscopically, and microscopically reduces light reflection loss at the groove. This allows more light to be received and utilized at various angles of incidence from the macro to the micro level, improving the light-trapping effect of the second region and thus increasing the photoelectric conversion efficiency of the photovoltaic cell. Furthermore, the slope, acting as a transition region between the base surface and the first region, divides the transition region into at least two regions with differences in elevation, based on the design of the stepped surface. On the one hand, it improves the overall flatness of the second region, which is advantageous for the subsequent formation of a film layer of uniform thickness on the first surface.Furthermore, both the stepped surface and the transition with multiple levels of small height differences can reduce the degree of stress concentration during film deposition, thereby reducing the risk of film tears or delamination. On the other hand, it is advantageous that the photogenerated charge carriers in the second region migrate rapidly to the nearest first region, thus shortening the lateral transfer distance of the photogenerated charge carriers and reducing the recombination probability of the photogenerated charge carriers.On the other hand, the stepped surface can avoid excessively high or low local light intensity in the slope, and the slope as a whole can distribute the density of photogenerated charge carriers, thus avoiding an excessive density of photogenerated charge carriers near the electrode located in the first region, thereby reducing the risk of a local hot-spot effect occurring in the photovoltaic cell.

[0167] How Fig. 16, Fig. 17, Fig. 18 to Fig. As shown in Figure 19, the photovoltaic cell comprises a substrate 100 with a first surface 101 and a second surface 102, which face each other. The first surface 101 has first regions 111 and second regions 121, which are arranged alternately in a first direction X. The substrate 100 has a base surface 131 embedded in the second regions 121, at least two inclined surfaces 161 connecting the base surface 131 and the first region 111, and a stepped surface 171 connecting two adjacent inclined surfaces 161. The base surface 131, the inclined surface 161, and the stepped surface 171 enclose a groove 151. The at least two inclined surfaces 161 are inclined towards the first region 111.The ground surface 131 is designated as the first structured surface, encompassing several first pyramids 131a; the stepped surface 171 is designated as the second structured surface, encompassing several second pyramids 171a. The base of a first pyramid 131a is larger than the base of a second pyramid 171a, and the height of a first pyramid 131a is greater than the height of a fourth pyramid 171a.

[0168] Fig. Figure 16 is a diagram showing a sixth partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure. Fig. Figure 17 is a diagram showing a first enlarged view of the substrate in which Fig. The dashed box B shown in 16 is shown. Fig. Figure 18 is a diagram showing a second enlarged view of the substrate in which the Fig. The dashed box B shown in 16 is shown. Fig. Figure 19 is another schematic diagram of a three-dimensional scanning electron microscopy (SEM) of a substrate in a photovoltaic cell according to an embodiment of the present disclosure.

[0169] It should be noted that an individual groove 151 comprises at least two inclined surfaces 161 and at least one stepped surface 171 and can be considered a multi-layered stepped structure. A surface formed jointly by several inclined surfaces 161 and the stepped surface 171, which connects two adjacent inclined surfaces 161 in the same groove 151, is considered a slope 141. On the one hand, it is advantageous to use the slope 141 to form a stepped light propagation path in the groove 151, so that the light incident on the groove 151 is reflected multiple times between the inclined surfaces 161 and the stepped surface 171 and can finally be absorbed and utilized by the second region 121.On the other hand, the stepped light propagation path is advantageous because it widens the optical path, thus improving the absorption and utilization rate of the slope 141 for long-wavelength light, such as infrared light. Furthermore, the stepped surface 171 is designed as a second structured surface comprising several second pyramids 171a, and compared to the first pyramids 131a contained in the base surface 131, both the base and height of the second pyramids 171a are smaller.First, it is advantageous to distribute the light incident on the slope 141 more evenly with the help of the smaller second pyramids 171a, thus avoiding excessively high or low local light intensity on the slope 141, improving the overall light absorption and utilization of the slope 141, and reducing light emission. This further reduces the reflection loss of light at the slope 141 and improves the photoelectric conversion efficiency of the photovoltaic cell under low light conditions or at oblique incidence. Second, it is advantageous to enhance the light scattering at the slope 141, thus improving the absorption rate of the slope 141 for short-wavelength light, such as blue and ultraviolet light.In this way, the combined effect of several aspects can macroscopically achieve a multi-stage light-capturing effect by means of the multi-layered step structure, which is jointly formed by the inclined surfaces 161 and the step surface 171, and the reflection loss of light at the groove 151 can be reduced microscopically by means of the step surface 171, which includes several second pyramids 171a, and more light at different angles of incidence can be received and used from the macro to the micro level, so that the light-capturing effect of the second region 121 is improved, thereby increasing the short-circuit current of the photovoltaic cell and improving the photoelectric conversion efficiency of the photovoltaic cell.

[0170] Furthermore, the slope 141, as a transition region between the ground surface 131 and the first region 111, subdivides the transition region into at least two regions with differences in elevation based on the design of the stepped surface 171. On the one hand, it is advantageous to reduce the steepness of the slope 141, i.e., it improves the overall flatness of the second region 121, which is beneficial for the subsequent formation of a film layer of uniform thickness on the first surface 101. Moreover, both the stepped surface 171 and the transition with multiple levels of small differences in elevation can reduce the degree of stress concentration during film deposition and thereby reduce the risk of film cracking or delamination.On the other hand, it is advantageous that the photogenerated charge carriers in the second region 121 migrate rapidly to the nearest first region 111, and that the lateral transfer distance of the photogenerated charge carriers is reduced, thus reducing the recombination probability of the photogenerated charge carriers and thereby improving the photoelectric conversion efficiency of the photovoltaic cell. Furthermore, the stepped surface 171 can prevent excessively high or low local light intensity in the slope 141, and the slope 141 as a whole can distribute the density of the photogenerated charge carriers, thus avoiding an excessive density of photogenerated charge carriers near the electrode located in the first region 111, thereby reducing the risk of a local hot-spot effect occurring in the photovoltaic cell.

[0171] It should be noted that in some cases not all inclined surfaces 161 exhibit pyramids. Only the stepped surface 171 includes several second pyramids 171a, while the inclined surfaces 161 are smooth surfaces to further improve the overall flatness of the second region 121, thus optimizing the thickness uniformity of the film layer subsequently formed on the second region 121. It should be noted that the inclined surfaces 161 are smooth surfaces compared to the stepped surface 171, which has the second pyramidal structures 171a. Due to the influence of the formation process, the surface of the inclined surface 161 is not necessarily as smooth as a polished surface, and minute elevations or depressions may be present without a typical pyramidal structure, although the overall flatness is significantly higher than that of the stepped surface 171.

[0172] To make the difference between the first pyramids 131a and the second pyramids 171a even clearer to the expert, the second region 121 can be subdivided into a transition region 122, a second subregion 123, and another transition region 122, arranged sequentially along the first direction X. A transition region 122 is defined as the region occupied by a slope 141 within the second region 121, and a second subregion 123 is defined as the region occupied by a ground surface 131 within the second region 121. In other words, the first pyramids 131a are located in the second subregion 123, and the second pyramids 171a are located in the transition region 122. Furthermore, each of the two first regions 111 is connected to a corresponding transition region 122 on two opposite sides of the same second region 121 along the first direction X.

[0173] The embodiments of the present disclosure are described in more detail below with reference to the accompanying drawings.

[0174] As in Fig. 17 or Fig. As shown in Figure 18, the number of first pyramids 131a is lower than the number of second pyramids 171a within the same arrangement area because the base of the first pyramids 131a is larger than that of the second pyramids 171a. In other words, compared to the distribution density of the first pyramids 131a on the ground surface 131, the second pyramids 171a on the stepped surface 171 have a higher distribution density. On the one hand, it is advantageous to increase the surface area and specific surface area of ​​the stepped surface 171 so that the stepped surface 171 has more surfaces for receiving incident light, which helps to ensure that more light can be reflected, refracted, or absorbed by the stepped surface 171 and utilized.On the other hand, it is advantageous to reduce the gap between adjacent second pyramids 171a so that the stepped surface 171 can absorb the incident light more efficiently, thus reducing the probability of light escaping from the space between adjacent second pyramids 171a. Furthermore, a greater number of second pyramids 171a allows the incident light to be scattered more evenly, increasing the likelihood that the incident light enters the substrate 100 and is then absorbed and utilized. It is also advantageous to reduce the sensitivity of the stepped surface 171 to the angle of incidence of the light, enabling the stepped surface 171 to maintain a higher absorption rate of light at different angles of incidence.

[0175] In some embodiments, the base of the second pyramid 171a can be in the range of 0.5 µm to 1.5 µm and may, for example, be 0.6 µm, 0.7 µm, 0.8 µm, 0.9 µm, 1 µm, 1.1 µm, 1.2 µm, 1.3 µm, or 1.4 µm, etc. The base of the first pyramid 131a can be in the range of 2 µm to 3 µm and may, for example, be 2.1 µm, 2.2 µm, 2.3 µm, 2.4 µm, 2.5 µm, 2.6 µm, 2.7 µm, 2.8 µm, or 2.9 µm, etc.

[0176] For example, the base of the second pyramid 171a can be a quadrilateral with a size of 1 µm × 1 µm, and the base of the first pyramid 131a can be a quadrilateral with a size of 2.5 µm × 2.5 µm.

[0177] As in Fig. 17 or Fig. As shown in Figure 18, the height of the first pyramid 131a is designed to be greater than the height of the second pyramid 171a. In this way, the second pyramid 171a, with its lower height compared to the first pyramid 131a, also facilitates the reduction of the propagation distance of the photogenerated charge carriers on the surface 171, thereby reducing the recombination probability of the charge carriers in order to improve the photoelectric conversion efficiency of the photovoltaic cell.

[0178] In some embodiments, the height of the fourth pyramid 171a can be in the range of 0.5 µm to 1.5 µm and may be, for example, 0.6 µm, 0.7 µm, 0.8 µm, 0.9 µm, 1 µm, 1.1 µm, 1.2 µm, 1.3 µm, or 1.4 µm, etc. The height of the first pyramid 131a can be in the range of 2 µm to 3 µm and may be, for example, 2.1 µm, 2.2 µm, 2.3 µm, 2.4 µm, 2.5 µm, 2.6 µm, 2.7 µm, 2.8 µm, or 2.9 µm, etc.

[0179] In some embodiments, the reflectance of the stepped surface 171 can be in the range of 10 to 11 and may be, for example, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, or 10.9, etc. The reflectance of the base surface 131 can be in the range of 12 to 13 and may be, for example, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, or 12.9, etc.

[0180] In some embodiments, such as in Fig. 16, Fig. 17 to Fig. As shown in Figure 18, several inclined surfaces 161 and stepped surfaces 171, which connect adjacent inclined surfaces 161, together form a slope 141 in the same groove 151, wherein an orthogonal projection surface of the slope 141 onto the ground surface 131 is a first surface and a surface of the ground surface 131 is a second surface. The ratio of the first surface to the second surface can be in the range of 0.005 to 0.02. For example, it can be 0.006, 0.007, 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, or 0.019, etc. In this way, the surface area of ​​the groove 151 is mainly determined by the area of ​​the bottom surface 131.The design of the first pyramidal structures 131a contained on the base surface 131 with a greater height is advantageous in order to provide a larger surface area and more attachment points, so that the film layer subsequently applied to the surface of the groove 151 is better attached and the surface of the groove 151 can be covered more evenly, which in turn is advantageous in order to reduce defects and pores in the film layer and to improve the quality and performance of the film layer.

[0181] It should be noted that both the first region 111 and the second region 121 extend along a third direction. Therefore, the groove 151 can be considered an elongated trench extending along the third direction, with the ground surface 131, the inclined surfaces 161, and the stepped surfaces 171 having identical dimensions in the third direction. The area sizes of the orthogonal projections of the ground surface 131 and the slope 141 onto the ground surface 131 depend primarily on their respective lengths in the first direction X.In this way, by taking the length of the base surface 131 in the first direction X as the first length L1 and the length of the orthogonal projection of the slope 141 onto the base surface 131 in the first direction X as the second length L2, and by setting the ratio of the first area to the second area to between 0.005 and 0.02, i.e., by setting the ratio of the second length L2 to the first length L1 in the range of 0.005 to 0.02, the surface area of ​​the groove 151 is determined primarily by the area of ​​the base surface 131. Designing the first pyramidal structures 131a on the base surface 131 with a greater height is advantageous, as it provides a larger surface area and more attachment points, thus allowing the film layer subsequently applied to the surface of the groove 151 to adhere better and to cover the surface of the groove 151 more uniformly.It is advantageous to allow the deposited film layer, such as a passivation layer, an inverse reduction layer or a transparent conductive layer, to cover the surface of the groove 151 more uniformly, which has a positive effect on reducing defects and pores in the film layer and on improving the quality and performance of the film layer.

[0182] In some cases, such as in Fig. 17 or Fig. As shown in Figure 18, the first length L1 of the soil surface 131 along the first direction X lies in the range of 200 µm to 800 µm. For example, the first length L1 can be 250 µm, 300 µm, 350 µm, 400 µm, 450 µm, 500 µm, 550 µm, 600 µm, 650 µm, 700 µm or 750 µm, etc.

[0183] In some embodiments, such as in Fig. 17 or Fig. As shown in Figure 18, the substrate 100 arranged in the second region 121 can comprise two inclined surfaces 161 and a stepped surface 171 connecting two adjacent inclined surfaces 161. Along the second direction Y, the distance between the stepped surface 171 and the first region 111 is a first distance H5, and the distance between the stepped surface 171 and the ground surface 131 is a second distance H6. The ratio of the first distance H5 to the second distance H6 can be in the range of 0.6 to 1.3. The second direction Y is the direction of the thickness of the substrate 100. Furthermore, the depth of the groove 151 can be the sum of the first distance H5 and the second distance H6.

[0184] It should be noted that a plane in which the bases of most of the second pyramids 171a arranged in the stepped surface 171 lie is taken as the fourth reference plane, and a plane in which the bases of most of the first pyramids 131a arranged in the ground surface 131 lie is taken as the second reference plane. Along the second direction Y, the first distance H5 between the stepped surface 171 and the first region 111 refers to the distance between the fourth reference plane and the reference plane on which the first region 111 is arranged, and the second distance H6 between the stepped surface 171 and the ground surface 131 refers to the distance between the fourth reference plane and the second reference plane.

[0185] Furthermore, the base surface of the second pyramid 171a is a plane in which the base of the second pyramid 171a is arranged. The orthogonal projection pattern of the base of the second pyramid 171a on the substrate 100 can be a regular quadrilateral or an irregular polygon. It should be noted that the base surfaces of all second pyramids 171a contained in the stepped surface 171 may lie in different planes, but more than half of the second pyramids 171a have base surfaces that lie almost in the same plane, which can serve as the reference plane of the stepped surface 171. The base surface of the first pyramid 131a is a plane in which the base of the first pyramid 131a is arranged. The orthogonal projection pattern of the base of the first pyramid 131a on the substrate 100 can be a regular quadrilateral or an irregular polygon.It should be noted that the ground surfaces of all first pyramids 131a contained in the ground area 131 may lie in different planes, but more than half of the number of first pyramids 131a have ground surfaces that lie almost in the same plane, which can serve as the reference plane of the ground area 131.

[0186] Furthermore, in practical applications, the substrate arranged in the second region can be designed to include (N+1) inclined surfaces and N stepped surfaces, each connecting adjacent inclined surfaces. N can be any positive integer besides 1. For example, N can be 2, 3, or 4, etc.

[0187] In some cases, such as in Fig. As shown in Figure 18, the first region 111 is designated as the third structured surface, comprising several third pyramids 111a. The ground surfaces of all third pyramids 111a contained in the first region 111 may lie in different planes; however, more than half of the third pyramids 111a have ground surfaces that lie almost in the same plane, which can serve as the third reference plane. Based on this value, the first distance H5 is the distance between the fourth reference plane, in which the stepped surface 171 is arranged, and the third reference plane, in which the first region 111 is arranged.

[0188] It should be noted that the fourth reference plane of the stepped surface 171 and the second reference plane of the ground surface 131 in Fig. 17 or Fig. 18 are shown with denser dashed lines, and the third reference plane of the first region 111 in Fig. 18 is shown with denser dashed lines.

[0189] In some embodiments, such as in Fig. 17 or Fig. As shown in Figure 18, along the second direction Y the ratio of the first distance H5 to the second distance H6 can be 0.7, 0.8, 0.9, 1, 1.1 or 1.2 etc.

[0190] For example, the first distance H5 between the stepped surface 171 and the first region 111 along the second direction Y lies in the range of 5 µm to 7 µm. For example, it can be 5.1 µm, 5.2 µm, 5.3 µm, 5.4 µm, 5.5 µm, 5.6 µm, 5.7 µm, 5.8 µm, 5.9 µm, 6 µm, 6.1 µm, 6.2 µm, 6.3 µm, 6.4 µm, 6.5 µm, 6.6 µm, 6.7 µm, 6.8 µm, or 6.9 µm, etc.

[0191] In some embodiments, the second distance H6 between the stepped surface 171 and the bottom surface 131 along the second direction Y lies in the range of 5.5 µm to 7.5 µm. It can be, for example, 5.6 µm, 5.7 µm, 5.8 µm, 5.9 µm, 6 µm, 6.1 µm, 6.2 µm, 6.3 µm, 6.4 µm, 6.5 µm, 6.6 µm, 6.7 µm, 6.8 µm, 6.9 µm, 7 µm, 7.1 µm, 7.2 µm, 7.3 µm, or 7.4 µm, etc.

[0192] In some embodiments, such as in Fig. 17 or Fig. As shown in Figure 18, the inclination angle β of the surface 161, which is inclined towards the second region 121 and is located near the first region 111, lies in the range of 40° to 55°. For example, the inclination angle β can be 40.5°, 41°, 41.5°, 42°, 42.5°, 43°, 43.5°, 44°, 44.5°, 45°, 45.5°, 46°, 46.5°, 47°, 47.5°, 48°, 48.5°, 49°, 49.5°, 50°, 50.5°, 51°, 51.5°, 52°, 52.5°, 53°, 53.5°, 54°, or 54.5°, etc. It should be noted that the inclination angles β of the various surfaces 161 inclined towards the first region 111 may either be identical or exhibit slight variations. However, the numerical range of the inclination angle β for each surface 161 inclined towards the first region 111 can be set to 40° to 55°.

[0193] It should be noted that by designing the inclination angle β of the surface 161, which is inclined towards the first region 111, within 40° to 55°, excessive steepness of the inclined surface 161 can be avoided. As a transition region between the ground surface 131 and the first region 111, the inclined surface 161 reduces abrupt differences in elevation between adjacent regions of the slope. In other words, with the second surface 102 as the reference plane, this design minimizes differences in elevation between adjacent regions along the first direction X across the inclined surface 161, thus enabling a gradual morphological transition from the elevated first region 111 to the lower-lying ground surface 131 on the first surface 101.This smooth transition is advantageous for achieving a uniform layer thickness (for example, of passivation layers) on the first surface 101, thereby improving the passivation effectiveness.

[0194] Furthermore, if the inclination angle β of the surface 161 inclined towards the first region 111 is set to less than 40°, compared to an inclination angle β of greater than or equal to 40°, with a constant area of ​​the inclined surface 161, the size of the transition region 122 in the first direction X is increased, thus reducing the number of first regions 111 that can be arranged on the entire first surface 101. Therefore, it is advantageous to dimension the inclination angle β of the surface 161 inclined towards the first region 111 to a value of at least 40° to ensure that the inclined surface 161 has a certain area, while simultaneously reducing the overall size of the inclined surface 161 in the first direction X, i.e., reducing the proportion of the transition region 122 occupied by the transition region 122 over the entire first surface 101.

[0195] It should be noted that with regard to Fig. 17 or Fig. 18 The plane on which a large part of the ground surfaces of the first pyramids 131a contained in the ground surface 131 lies is used as the reference surface of the ground surface 131. Based on this factor, the angle of inclination β of the surface 161 inclined towards the first region 111 refers to an acute angle formed between the reference plane of the inclined surface 161 and the reference plane of the ground surface 131.

[0196] In some embodiments, as in Fig. Figure 18 shows the first region 111 as the third structured surface, comprising several third pyramids 111a. The dimensional relationships between the first pyramids 131a, the second pyramids 171a, and the third pyramids 111a are described in more detail below.

[0197] In some cases, such as in Fig. As shown in Figure 18, the third pyramid, 111a, has a larger base than the second pyramid, 171a, and a smaller base than the first pyramid, 131a. That is, the second pyramid, 171a, has the smallest base, and the first pyramid, 131a, has the largest base.

[0198] In some examples, the base of the third pyramid 111a can be in the range of 1 µm to 2 µm and, for example, be 1.1 µm, 1.2 µm, 1.3 µm, 1.4 µm, 1.5 µm, 1.6 µm, 1.7 µm, 1.8 µm, or 1.9 µm, etc. The base of the second pyramid 171a can be in the range of 0.5 µm to 1.5 µm, and the base of the first pyramid 131a can be in the range of 2 µm to 3 µm.

[0199] In some cases, such as in Fig. As shown in Figure 18, the height of the third pyramid 111a is greater than the height of the second pyramid 171a and less than the height of the first pyramid 131a. That is, the second pyramid 171a has the smallest height, and the first pyramid 131a has the greatest height.

[0200] In some examples, the height of the third pyramid-shaped pyramid 111a ranges from 1.5 µm to 2.5 µm and can be, for example, 1.6 µm, 1.7 µm, 1.8 µm, 1.9 µm, 2 µm, 2.1 µm, 2.2 µm, 2.3 µm, or 2.4 µm, etc. The height of the second pyramid 171a ranges from 0.5 µm to 1.5 µm, and the height of the first pyramid 131a ranges from 2 µm to 3 µm.

[0201] In some cases, such as in Fig. As shown in Figure 18, the third structured surface has a lower reflectivity than the first structured surface. That is, the stepped surface 171 has the lowest reflectivity, and the ground surface 131 has the highest reflectivity.

[0202] In some embodiments, the reflectance of the third structured surface of the first region 111 is in the range of 10.5 to 11.5 and can be, for example, 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3, or 11.4, etc. The reflectance of the stepped surface 171 is in the range of 10 to 11, and the reflectance of the bottom surface 131 is in the range of 12 to 13.

[0203] It should be noted that for the first surface 101, the three examples mentioned above can be present simultaneously, or that one of them can be selected, or that two of them can be selected.

[0204] In some embodiments, such as in Fig. As shown in Figure 18, the vertex angles of the first pyramid 131a, the second pyramid 171a, and the third pyramid 111a can lie in a range of 65° to 80° and may be, for example, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, or 79°, etc. In this way, it is advantageous to capture incident light more efficiently, for example, by means of a pyramid-shaped pyramid with a smaller vertex angle, so that light from a greater number of angles of incidence can be completely reflected into the first surface 101, thus increasing the total amount of light entering the first surface 101.

[0205] It should be noted that the angle formed by the two opposite edges of the pyramid can be considered the apex angle of the pyramid.

[0206] Some embodiments are in Fig. Figure 20, which is a schematic diagram showing a seventh partial sectional view of a photovoltaic cell according to an embodiment of the present disclosure, wherein the photovoltaic cell further comprises a first protective layer 103 covering the bottom surface 131, the inclined surfaces 161 and the stepped surfaces 171.

[0207] In some cases, the first protective layer 103 can cover the ground surface 131, the inclined surfaces 161, and the stepped surfaces 171. In such cases, the surface morphology of the section of the first protective layer 103 facing the ground surface 131 also exhibits a structured morphology similar to that of the ground surface 131, and the surface morphology of the section of the first protective layer 103 facing the stepped surfaces 171 also exhibits a structured morphology similar to that of the stepped surfaces 171. It should be noted that with regard to Fig. 17, Fig. 18, Fig. 19 to Fig.20 On the one hand, the first protective layer 103 helps to protect the morphology of the first pyramids 131a and the second pyramids 171a when, for example, other film layers are subsequently formed on the second regions 121 and structuring is carried out, and the first protective layer 103 can serve as an etching barrier to prevent damage to the first pyramids 131a and the second pyramids 171a from the structuring process, thus advantageously ensuring that the second regions 121 have a relatively lower reflectivity.On the other hand, the first protective layer 103 facilitates the improvement of the optical properties of the second regions 121 in order to further reduce the reflection loss of the second regions 121, for example to reduce the reflectivity of the entire surface of the photovoltaic cell arranged on the second regions 121 and ultimately to improve the absorption and utilization rate of the second regions 121 for light, thereby increasing the photoelectric conversion efficiency of the photovoltaic cell.

[0208] A surface formed jointly by several inclined surfaces 161 and the stepped surface 171, which connects two adjacent inclined surfaces 161 in the same groove 151, is considered a slope 141, and the groove 151 including the slope 141 can be regarded as a multi-layered stepped structure. On the one hand, it is advantageous to form a stepped light propagation path in the groove 151 so that the light incident on the groove 151 is reflected multiple times between the inclined surfaces 161 and the stepped surface 171 and can finally be absorbed and utilized by the second region 121. On the other hand, the stepped light path is advantageous because the optical path widens, thus improving the absorption and utilization rate of the slope 141 for long-wavelength light, such as infrared light.On the other hand, compared to the first pyramids 131a contained on the ground surface 131, both the base and the height of the second pyramids 171a contained on the stepped surface 171 are smaller. Firstly, it is advantageous to distribute the light incident on the slope 141 more evenly with the help of the smaller second pyramids 171a, so that excessively high or low local light intensity on the slope 141 is avoided, the overall light absorption and utilization of the slope 141 is improved, and light emission is reduced, thereby further reducing the reflection loss of light on the slope 141. Secondly, it is advantageous to enhance the light scattering on the slope 141, thus improving the absorption rate of the slope 141 for short-wavelength light, such as blue and ultraviolet light.In this way, the comprehensive effect of several aspects can achieve a multi-stage light-capturing effect macroscopically, and microscopically the reflection loss of light at the groove 151 can be reduced, and more light at different angles of incidence can be received and used from the macro to the micro level to improve the light-capturing effect of the second region 121 and thus increase the photoelectric conversion efficiency of the photovoltaic cell.

[0209] Furthermore, the slope 141, as a transition region between the ground surface 131 and the first region 111, subdivides the transition region into at least two regions with differences in elevation based on the design of the stepped surface 171. On the one hand, this contributes to improving the overall flatness of the second region 121, which is advantageous for the subsequent formation of a film layer of uniform thickness on the first surface 101. In addition, both the stepped surface 171 and the transition with multiple levels of small elevation differences can reduce the stress concentration during film deposition and thereby reduce the risk of film cracking or delamination.On the other hand, it is advantageous that the photogenerated charge carriers in the second region 121 migrate rapidly to the nearest first region 111, thus reducing the lateral transfer distance of the photogenerated charge carriers and thereby reducing the recombination probability of the photogenerated charge carriers. Furthermore, the stepped surface 171 can prevent excessively high or low local light intensity in the slope 141, and the slope 141 as a whole can distribute the density of the photogenerated charge carriers, thus preventing an excessive density of photogenerated charge carriers near the electrode located in the first region 111 and reducing the risk of a local hot-spot effect occurring in the photovoltaic cell.

[0210] Experts in this field will understand that the above-mentioned various embodiments are specific examples of implementing the present disclosure. In practical applications, various changes to the form and details can be made without deviating from the core and scope of the embodiments of the present disclosure. Any person skilled in this field can make various modifications and changes without deviating from the core and scope of the embodiments of the present disclosure. Therefore, the scope of protection of the embodiments of the present disclosure should correspond to the scope defined by the claims.

Claims

[1] Photovoltaic cell, comprising: a substrate having a first surface and a second surface opposite each other, the first surface having first regions and second regions arranged alternately in a first direction; and Grooves arranged in the substrate at the second regions and embedded in the substrate, wherein a single groove of the grooves has a bottom surface and an inclined surface connecting the bottom surface to a first region adjacent to the bottom surface, the inclined surface being inclined in the direction of the first region; where the ground surface is provided as a first textured surface with several first pyramids, and the first region is provided as a third textured surface with several third pyramids. [2] Photovoltaic cell according to claim 1, wherein in the same groove along the first direction a length of the bottom surface is the first length and a length of the inclined surface is the second length, and a ratio of the second length to the first length is in the range of 0.001 to 0.

005. [3] Photovoltaic cell according to claim 1, wherein along the second direction, which is a thickness direction of the substrate, the depth of the groove is in the range of 2 µm to 4 µm. [4] Photovoltaic cell according to claim 1, wherein the inclination angle of the surface inclined towards the first region is in the range of 40° to 55°. [5] Photovoltaic cell according to claim 1, further comprising a first protective layer covering the ground surface and the inclined surface. [6] Photovoltaic cell according to claim 5, wherein the first protective layer is made of a semiconductor material doped with a doping element, silicon oxide, phosphosilicate glass or borosilicate glass. [7] Photovoltaic cell according to claim 1, wherein a single groove comprises at least two inclined surfaces and a stepped surface connecting two adjacent inclined surfaces; the bottom surface, the at least two inclined surfaces and the stepped surface together form the groove; and the stepped surface is provided as a second textured surface containing multiple second pyramids, wherein a base size of a single first pyramid is larger than a base size of a single second pyramid, and a height of a single first pyramid is greater than a height of a single second pyramid. [8] Photovoltaic cell according to claim 7, wherein in the same groove several inclined surfaces and stepped surfaces connecting adjacent inclined surfaces together form a slope, wherein an orthographic projection surface of the slope on the ground surface is a first surface, a surface of the ground surface is a second surface and a ratio of the first surface to the second surface is in the range of 0.005 to 0.

02. [9] Photovoltaic cell according to claim 7, wherein the substrate arranged in the second region comprises two inclined surfaces and a stepped surface connecting two adjacent inclined surfaces; along a second direction, which is a thickness direction of the substrate, a distance between the stepped surface and the first region is a first distance, and a distance between the stepped surface and the ground surface is a second distance, and a ratio of the first distance to the second distance is in the range of 0.6 to 1.

3. [10] Photovoltaic cell according to claim 1, wherein the first pyramids and the third pyramids satisfy any or any combination of the following relationships: The base size of a single third pyramid is smaller than the base size of a single first pyramid; The height of a single third pyramid is less than the height of a single first pyramid; The reflectivity of the third textured surface is lower than the reflectivity of the first textured surface; and The vertex angles of the first and third pyramids lie in a range of 65° to 80°. [11] Photovoltaic cell according to claim 1, further comprising: electrodes arranged at least on the first surface, wherein the electrodes are used to extract the photogenerated charge carriers generated in the substrate, wherein the first regions include at least regions where the orthographic projections of the electrodes are arranged on the substrate. [12] Photovoltaic cell according to claim 1, further comprising: a tunneling layer that is arranged on the second surface; a first doped semiconductor layer, which is doped with a first doping element and is located on a side of the tunneling layer away from the second surface; a second doped semiconductor layer doped with a second doping element and arranged on the first regions, wherein a conductivity type of the first doping element differs from a conductivity type of the second doping element; a first passivation layer located on a side of the first doped semiconductor layer away from the tunneling layer; a second passivation layer, which is located on a side of the second doped semiconductor layer away from the substrate and is located on the second regions; first electrodes that are in ohmic contact with the first doped semiconductor layer; and second electrodes that are embedded in the second passivation layer and are in ohmic contact with the second doped semiconductor layer. [13] Photovoltaic cell according to claim 1, further comprising: a tunneling layer that is arranged on the second surface; a first doped semiconductor layer, which is doped with a first doping element and is located on a side of the tunneling layer away from the second surface; a second doped semiconductor layer doped with a second doping element and arranged on the first regions, wherein a conductivity type of the first doping element differs from a conductivity type of the second doping element; a first protective layer that is arranged on the second regions; a first passivation layer located on a side of the first doped semiconductor layer away from the tunneling layer; a second passivation layer, which is located on a side of the second doped semiconductor layer away from the substrate and is located on the second regions; first electrodes embedded in the first passivation layer and in ohmic contact with the first doped semiconductor layer; and second electrodes that are in ohmic contact with the second doped semiconductor layer. [14] Photovoltaic module, comprising: at least one cell string, each formed by connecting several photovoltaic cells according to claim 1; at least one encapsulation adhesive film configured to cover one surface of the at least one cell strand; and at least one cover plate configured to cover a surface of the at least one encapsulation adhesive film that is remote from the at least one cell strand.

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