Solar cells and photovoltaic modules

Abstract

This will further improve the electrical performance of solar cells, such as their photoelectric conversion efficiency. [Solution] The solar cell has a base layer having a first face and a second face adjacent to each other, and at least one of the first face and the second face being a side surface of the base layer, and further a multi-pyramid common body having a common face is provided on the base layer at a common edge and / or common angle where the first face and the second face are adjacent to each other, and when viewed toward the first face, the multi-pyramid common body includes a first pyramidal structure formed by being enclosed by a plurality of first triangular planes and a plurality of third triangular planes, and when viewed toward the second face, the multi-pyramid common body includes a second pyramidal structure formed by being enclosed by a plurality of second triangular planes and a plurality of third triangular planes, the third triangular plane being a common face, and the triangular planes among the first triangular plane, the second triangular plane and the third triangular plane are triangles or quasi-triangulars.

Description

Technical Field

[0001] This application relates to the technical field of solar cells, and particularly to solar cells and photovoltaic modules.

Background Art

[0002] The base layer of a solar cell is a core component of the solar cell. However, in current solar cells, problems such as intractable defect states and impurity contamination that cannot be completely removed still exist at some positions of the base layer. These problems will limit the further improvement of the photoelectric conversion efficiency of the solar cell.

Summary of the Invention

[0003] In order to solve the above technical problems, this application discloses a solar cell and a photovoltaic module.

[0004] In a first aspect, this application provides a solar cell, which includes a base layer having a first surface and a second surface adjacent to each other, and at least one of the first surface and the second surface is a side surface of the base layer, at a common ridge line and / or a common angle where the first surface and the second surface are adjacent to each other, a multi-pyramid common body having a common surface with the base layer is further provided, when viewed towards the first surface, the multi-pyramid common body includes a first pyramid configuration surrounded by a plurality of first triangular planes and a plurality of third triangular planes; when viewed towards the second surface, the multi-pyramid common body includes a second pyramid configuration surrounded by a plurality of second triangular planes and a plurality of the third triangular planes; the third triangular plane is the common surface; and the triangular planes among the first triangular plane, the second triangular plane, and the third triangular plane are triangles or quasi-triangles.

[0005] Furthermore, the multi-pyramid common body is a double-pyramid common body. The first surface is the first side surface of the base layer, the second surface includes the first sub-surface, the first sub-surface is either the light-receiving surface, the non-light-receiving surface, or the second side surface of the base layer, and the double pyramid common body is provided on the common ridge line located adjacent to the first surface and the first sub-surface.

[0006] Furthermore, the aforementioned multi-pyramid common body is a triple-pyramid common body, The first surface is the first side surface of the base layer, the second surface includes a first sub-surface and a second sub-surface, the first sub-surface being a light-receiving surface or a non-light-receiving surface of the base layer, and the second sub-surface being a second side surface adjacent to the first side surface, and the triple pyramid common body is provided at the common angle located adjacent to the first surface, the first sub-surface and the second sub-surface.

[0007] Furthermore, the solar cell is a slice cell, the base layer has a cut surface, the surface of the base layer includes the cut surface, and / or The first surface and the second surface are perpendicular to each other.

[0008] Furthermore, in the orthographic projection of the first surface, the first pyramidal structure has a first diagonal length L1, where 0.1 μm ≤ L1 ≤ 7 μm. In the orthographic projection of the second surface, the second pyramidal structure has a second diagonal length L2, where 0.1 μm ≤ L2 ≤ 7 μm. In any of the aforementioned multi-pyramid commonalities, 0.5 ≤ L1 / L2 ≤ 2.

[0009] Furthermore, in a direction perpendicular to the first surface, the first pyramidal structure has a first height H1, where 0.1 μm ≤ H1 ≤ 3 μm. In a direction perpendicular to the second surface, the second pyramidal structure has a second height H2, where 0.1 μm ≤ H2 ≤ 3 μm. In all of the aforementioned multi-pyramid commonalities, 0.5 ≤ H1 / H2 ≤ 2.

[0010] Furthermore, the common elements of the multi-pyramid are arranged along the length direction of the common ridge, The common ridge has a central region and edge regions located on both sides of the central region, the length of the diagonal of the multi-pyramid common body located in the central region is less than the length of the diagonal of the multi-pyramid common body located in the edge region, the height of the multi-pyramid common body located in the central region is less than the height of the multi-pyramid common body located in the edge region, and / or, there is one or more multi-pyramid common bodies corresponding to a 100 μm length region of the common ridge.

[0011] Furthermore, the number of the multiple pyramidal common bodies is at least 10, corresponding to a region of 100 μm in length along the common ridge.

[0012] Furthermore, the first face has a plurality of third pyramidal structures, and the second face has a plurality of fourth pyramidal structures.

[0013] Furthermore, in the orthographic projection of the first surface, the first pyramidal structure has a first diagonal length L1, where 0.1 μm ≤ L1 ≤ 7 μm, and the third pyramidal structure has a third diagonal length L3, where 0.1 μm ≤ L3 ≤ 7 μm and 0.5 ≤ L3 / L1 ≤ 2. In the orthographic projection of the second surface, the second pyramidal structure has a second diagonal length L2 such that 0.1 μm ≤ L2 ≤ 7 μm, and the fourth pyramidal structure has a fourth diagonal length L4 such that 0.1 μm ≤ L4 ≤ 7 μm and 0.5 ≤ L4 / L2 ≤ 2.

[0014] Furthermore, in a direction perpendicular to the first surface, the first pyramidal structure has a first height H1, where 0.1 μm ≤ H1 ≤ 3 μm, and the third pyramidal structure has a third height H3, where 0.1 μm ≤ H3 ≤ 5 μm and 0.5 ≤ H3 / H1 ≤ 2. In a direction perpendicular to the second surface, the second pyramidal structure has a second height H2, where 0.1 μm ≤ H2 ≤ 3 μm, and the fourth pyramidal structure has a fourth height H4, where 0.1 μm ≤ H4 ≤ 5 μm and 0.5 ≤ H4 / H2 ≤ 2.

[0015] Furthermore, the solar cell is A semiconductor layer located on the light-receiving surface and / or non-light-receiving surface of the base layer, A passivation layer located on the side of the semiconductor layer opposite to the base layer and on the side of the base layer, It further includes electrodes.

[0016] Furthermore, the solar cell is The aforementioned base layer, A first semiconductor layer and a first electrode are sequentially placed in the P-type conductive region of the non-light-receiving surface of the base layer, The system includes a second semiconductor layer and a second electrode, which are sequentially placed in the N-type conductive region of the non-light-receiving surface of the base layer, The first semiconductor layer and the second semiconductor layer are arranged alternately in a cross-finger shape, and there is an isolation region between the first semiconductor layer and the second semiconductor layer.

[0017] Furthermore, the solar cell is A first passivation layer provided on the side of the first semiconductor layer opposite to the non-light-receiving surface, A second passivation layer provided on the side of the second semiconductor layer opposite to the non-light-receiving surface, A third passivation layer provided on the light-receiving surface of the base layer, The system further includes a fourth passivation layer provided on the side surface of the base layer.

[0018] Furthermore, a first medium layer is provided between the base layer and the first semiconductor layer, and a second medium layer is provided between the base layer and the second semiconductor layer.

[0019] Furthermore, the first semiconductor layer is a first doped polysilicon layer or a first doped amorphous silicon layer deposited on the light-receiving surface of the base layer, the second semiconductor layer is a second doped polysilicon layer or a second doped amorphous silicon layer deposited on the medium layer, and / or The first passivation layer is one or more layers selected from an aluminum oxide layer, a silicon oxide layer, a silicon oxynitride layer, or a silicon nitride layer; the second passivation layer is one or more layers selected from an aluminum oxide layer, a silicon oxide layer, a silicon oxynitride layer, or a silicon nitride layer; the third passivation layer is one or more layers selected from an aluminum oxide layer, a silicon oxide layer, a silicon oxynitride layer, or a silicon nitride layer; the fourth passivation layer is one or more layers selected from an aluminum oxide layer, a silicon oxide layer, a silicon oxynitride layer, or a silicon nitride layer; and / or The first medium layer is at least one layer selected from a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, or a silicon nitride layer; the second medium layer is at least one layer selected from a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, or a silicon nitride layer.

[0020] Furthermore, the solar cell comprises the base layer and a first semiconductor layer and a first electrode sequentially provided on the light-receiving surface of the base layer and a medium layer, a second semiconductor layer, and a second electrode sequentially provided on the non-light-receiving surface of the base layer. The first semiconductor layer has a conductivity type different from that of the base layer.

[0021] Furthermore, the solar cell further comprises a fifth passivation layer provided on a surface of the first semiconductor layer opposite to the light-receiving surface and a sixth passivation layer provided on a surface of the second semiconductor layer opposite to the non-light-receiving surface and a seventh passivation layer provided on a side surface of the base layer.

[0022] Furthermore, the first semiconductor layer is formed by thermally diffusing a dopant element into the substrate layer, or the first semiconductor layer is a first doped polysilicon layer or a first doped amorphous silicon layer deposited on the light-receiving surface of the substrate layer, and the second semiconductor layer is a second doped polysilicon layer or a second doped amorphous silicon layer deposited on the medium layer, and / or The fifth passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the sixth passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the seventh passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers, and / or The media layer is at least one of the following layers: a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, and a silicon carbide layer.

[0023] In a second embodiment, the present application provides a photovoltaic module including the solar cell described in the first embodiment.

[0024] Compared to the prior art, this invention has at least the following beneficial effects.

[0025] In the solar cell of the present embodiment, the above-mentioned multi-pyramid common body is provided at the common edge and / or common angle where the first and second surfaces of the base layer are adjacent to each other. This is advantageous in reducing the defect state on the surface of the base layer, further improving the cleanliness of the base layer, and reducing the impact of impurity contamination in subsequent processes, and therefore contributes to further improving the photoelectric conversion efficiency of the solar cell.

[0026] To more clearly explain the technical modes in the embodiments of this application, the accompanying drawings used in the embodiments are briefly introduced below. However, the accompanying drawings in the following description represent only a portion of the embodiments of this application, and it will be apparent to those skilled in the art that other accompanying drawings can be obtained from these drawings without expending any creative effort. [Brief explanation of the drawing]

[0027] [Figure 1] This is a schematic diagram of the structure of the base layer of the solar cell according to the present embodiment. [Figure 2] This is an enlarged schematic diagram of the structure of part A in Figure 1. [Figure 3] This is a schematic diagram of the configuration of the common multi-pyramid structure in the embodiment of the present invention, viewed from a different direction. [Figure 4] This is a schematic diagram of the deformed triangular plane configuration in the embodiment of the present invention. [Figure 5] This is a schematic diagram of another multi-pyramid common structure in the embodiment of the present invention, viewed from a different direction. [Figure 6] This is a schematic diagram of the pyramidal structure of the first and second surfaces in the embodiment of the present invention. [Figure 7] This is a schematic diagram of the configuration of a back-contact type solar cell in an embodiment of the present invention. [Figure 8] This is a SEM view of the common multi-pyramid structure in the central region of the common ridge line in the embodiment of the present invention. [Figure 9] This is a SEM view of the common pyramidal structure in the edge region of the common ridge in the embodiment of the present invention. [Modes for carrying out the invention]

[0028] The technical modes of the embodiments of this application will be described clearly and completely below with reference to the accompanying drawings of the embodiments of this application, but it is clear that the embodiments described are only a part of the embodiments of this application and not all of them. Other embodiments that can be obtained by a person skilled in the art without expending any creative effort based on the embodiments of this application are also all within the scope of protection of this application.

[0029] In this application, terms such as “up,” “down,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inside,” “outside,” “vertical,” “horizontal,” “sideways,” and “vertical” indicate orientation or positional relationships based on those shown in the accompanying drawings. These terms are used primarily to better describe this application and its embodiments and are not intended to limit the shown devices, elements, or components to having a particular orientation or to being configured and operated in a particular orientation.

[0030] Furthermore, the terms described above can be used to indicate meanings other than orientation or positional relationships; for example, the term "above" can, in some cases, be used to indicate a specific dependency or connection. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0031] Furthermore, terms such as “attached,” “installed,” “provided,” “connected,” and “contact” should be understood in a broad sense. For example, they may be fixed connections, removable connections, or integrated configurations; they may be mechanical or electrical connections; they may be direct connections or indirect connections via an intermediate medium; and they may be internal connections between two devices, elements, or components. Those skilled in the art will be able to understand the specific meaning of the above terms in this application depending on the specific situation.

[0032] Furthermore, terms such as "first," "second," etc., are used primarily to distinguish between different devices, elements, or components (whether identical or different in specific type and configuration), and are not intended to express or suggest the relative importance or number of the devices, elements, or components shown. Unless otherwise specified, the term "plural" means two or more.

[0033] This invention provides a solar cell and a photovoltaic module, thereby improving the defect state of the solar cell's base layer and reducing the degree of impurity contamination, thereby further improving the electrical performance of the solar cell, such as its photoelectric conversion efficiency.

[0034] In a first embodiment, the present application provides a solar cell, as shown in Figures 1 to 3. Figure 1 is a schematic diagram of the structure of the base layer 1 of the solar cell according to an embodiment of the present application, Figure 2 is an enlarged schematic diagram of the structure of part A in Figure 1, and Figure 3 is a schematic diagram of the structure of the multi-pyramid common body 11 in the embodiment of the present application viewed from a different direction. In order to clearly show the structural characteristics of the multi-pyramid common body 11, Figure 2 simply illustrates one multi-pyramid common body 11 located at a common edge c and a common angle d, but the number of multi-pyramid common bodies 11 in the solar cell of the present application is not limited to the examples in Figure 2.

[0035] The solar cell of the present embodiment is The base layer 1 has a first surface a and a second surface b adjacent to each other, and at least one of the first surface a and the second surface b is a side surface of the base layer 1, A common multi-pyramid common body 11 having a common face is further provided at the common ridge c and / or common angle d where the first face a and the second face b of the base layer 1 are adjacent to each other.

[0036] As shown in Figures 2 and 3, when viewed toward the first face a (i.e., when viewed toward the first face a along the z-axis direction in Figure 2), the multi-pyramid common body 11 includes a first pyramidal configuration 111 formed by being enclosed by a plurality of first triangular planes 11a and a plurality of third triangular planes 11c. When viewed toward the second face b (i.e., when viewed toward the second face b along the x-axis direction in Figure 2, and / or when viewed toward the second face b along the y-axis direction in Figure 2), the multi-pyramid common body 11 includes a second pyramidal configuration 112 formed by being enclosed by a plurality of second triangular planes 11b and a plurality of third triangular planes 11c. The third triangular plane 11c is a common plane, and the triangular planes among the first triangular plane 11a, the second triangular plane 11b, and the third triangular plane 11c are triangles or quasi-triangular planes.

[0037] In other words, the multi-pyramid common body 11 of this application means that at the point where the first face a and the second face b are adjacent to each other, there exist polyhedral configurations that have corresponding pyramidal configurations when viewed from different viewpoints. As a result, the polyhedral configurations utilize a portion of the triangular planes of the different pyramidal configurations as common planes, and the common body is enclosed by the common planes and other triangular planes. Because the common body shares a portion of the faces of the different pyramidal configurations, it becomes a multi-pyramid common body 11. For example, if two pyramidal configurations are seen from two different viewpoints, and the common body obtained by utilizing the common planes of these two pyramidal configurations is called a double pyramidal common body, and if three pyramidal configurations are seen from three different viewpoints, and the common body obtained by utilizing the common planes of these three pyramidal configurations is called a triple pyramidal common body.

[0038] The pyramidal configurations viewed from each perspective are all formed by being enclosed by multiple triangular planes. These triangular planes may be standard triangles or sub-triangles. A sub-triangle is one whose overall shape approximates a standard triangle, and because some pyramidal configurations may have defects such as minute pits on their surface, the triangular planes enclosing the pyramidal configuration may be the aforementioned sub-triangles. For example, Figure 4 shows several selective triangular planes, where the angles of the triangles may be acute, fillets, or small pits may be present at the angles or sides of the triangles, but the overall shape remains triangular. The overall shape of the pyramidal configuration formed by being enclosed by these triangular planes should be broadly understood to have a standard pyramidal shape or a contour that approximates a pyramidal shape.

[0039] The fact that a pyramid structure is formed by being enclosed by multiple triangular planes means that the outer surface of the pyramid structure is formed by being enclosed by these triangular planes. Regarding the base of the pyramid structure, although there is no substantial constituent surface of the base, it can be understood as the orthographic projection plane of the pyramid structure on the plane corresponding to the base. Taking the first pyramid structure 111 as an example, when viewed toward the first plane a (i.e., along the z-axis direction in Figure 2 toward the first plane a), only the first triangular plane 11a and the third triangular plane 11c of the outer surface that encloses the first pyramid structure 111 are visible, and the base of the first pyramid structure 111 is not practically visible. However, the shape and dimensions of the base of the first pyramid structure 111 can be determined by the orthographic projection of the shape formed by being enclosed by the first triangular plane 11a and the third triangular plane 11c on the first plane a.

[0040] Furthermore, since the term "pyramid configuration" means having a configuration identical or similar to the shape of a pyramid, the pyramid configuration of this application is a three-dimensional configuration, not a two-dimensional one. For example, the first pyramid configuration 111 is visible in the direction toward the first face a, and scanning electron microscope images also confirm that the first triangular plane 11a and the third triangular plane 11c that surround the first pyramid configuration 111 have a common center point. Thus, the first pyramid configuration 111 is practically a three-dimensional configuration, not a two-dimensional one.

[0041] Furthermore, the first triangular plane 11a in this application refers to the triangular plane located on the first surface a, the second triangular plane 11b refers to the triangular plane located on the second surface b, and since the third triangular plane 11c is located on both the extending surface of the first surface a and the extending surface of the second surface b, the third triangular plane 11c is a common surface. This also shows that the distinction between the first triangular plane 11a, the second triangular plane 11b, and the third triangular plane 11c in this application is that they are located on different surfaces.

[0042] In the solar cell of this embodiment, the first surface a and the second surface b of the base layer 1 have the multi-pyramid common body 11 described above on a common ridge line c and / or common angle d adjacent to each other. This is advantageous in reducing the defect state on the surface of the base layer 1, improving the cleanliness of the base layer 1, and reducing the impact of impurity contamination on subsequent processes, thereby contributing to further improving the photoelectric conversion efficiency of the solar cell.

[0043] First, if the pyramidal structure is only present on the first surface a or the second surface b, and no multi-pyramid common structure 11 is formed at adjacent locations, the defect state at the adjacent locations of the two adjacent surfaces of the base layer 1 will increase, and a certain amount of dangling bonds will be present, making recombination more likely. However, in this invention, the presence of a multi-pyramid common structure 11 at adjacent locations reduces the defect state at those locations and reduces the presence of dangling bonds, thereby reducing recombination. Not only that, the presence of the multi-pyramid common structure 11 is also advantageous in increasing the stability of the mechanical structure of the base layer 1 at the common ridge c, making the common ridge c less susceptible to physical damage during the processing of the solar cell, thereby improving the durability and reliability of the solar cell.

[0044] Furthermore, the presence of common surfaces in the multi-pyramid common body 11 reduces the overall surface area, which is advantageous for improving the cleanliness of the base layer 1. Specifically, taking the example of the multi-pyramid common body 11 being a double pyramid common body, compared to the total surface area of ​​the eight triangular planes of two separate pyramids, the double pyramid common body has only six triangular planes, and since two triangular planes are eliminated, it has a smaller surface area. The characteristic of the multi-pyramid common body 11 having a small total surface area contributes to reducing the possibility of impurities and contaminants accumulating on the surface of the base layer 1, especially in gaps and corners near the common ridge c, while ensuring efficient use of light.

[0045] As can be seen from the above, by installing the multi-pyramid common body 11 at the location where the first surface a and the second surface b are adjacent to each other, the present invention can bring advantages to the solar cell base layer 1 such as a reduction in defect conditions, an improvement in structural stability, and an improvement in cleanliness. As a result, the adhesion of functional layers such as the passivation layer and anti-reflective layer that are subsequently fabricated on the base layer 1 can be improved, which is advantageous in further improving the passivation capability of the solar cell and optimizing the performance of the solar cell.

[0046] As an optional embodiment, referring again to Figures 2 and 3, the multi-pyramid common body 11 is a double pyramidal common body. In this embodiment, the double pyramidal common body can be formed by two adjacent faces and their common ridge c. The first face a is the first side surface of the base layer 1, and the second face b includes the first sub-face b1, which is either a light-receiving surface, a non-light-receiving surface, or the second side surface of the base layer 1, and the double pyramidal common body is located on the common ridge c where the first face a and the first sub-face b1 are adjacent to each other. The characteristic of this configuration, in which the double pyramidal common body is formed on two adjacent surfaces, contributes to optimizing the reflection path of light, effectively directing more light to the body of the base layer 1 and ensuring light utilization.

[0047] For example, if the first sub-surface b1 is a light-receiving or non-light-receiving surface of the base layer 1, the above-described double pyramidal common body is formed on the common ridge line c where the first side surface and the light-receiving (or non-light-receiving) surface are adjacent to each other. Such a configuration has the following advantages: Although the side surface of a solar cell is generally not directly exposed to sunlight, forming the above-described double pyramidal common body between the side surface and the light-receiving (or non-light-receiving) surface is equivalent to forming an additional light-absorbing region on the side surface of the base layer 1, which is advantageous in increasing light scattering, decreasing light reflection, improving the utilization of reflected light from the side surface, and further increasing the light utilization rate.

[0048] When the first sub-surface b1 is the second side surface of the base layer 1, the double pyramidal common body described above is formed on the common ridge c where the first and second side surfaces are adjacent to each other. This configuration returns light reflected from the side surface to the light-receiving surface, reduces light leakage from the side, and ensures that more light is absorbed and utilized by the battery. Furthermore, compared to the case where the multi-pyramidal common body 11 is not provided on the common ridge c, the double pyramidal common body located on the common ridge c is also advantageous in improving the structural stability of the base layer 1 and has better resistance to mechanical stress in the solar cell manufacturing process.

[0049] As another optional embodiment, as shown in Figure 2, the multi-pyramid common body 11 is a triple-pyramid common body. In this embodiment, the triple-pyramid common body can be formed by three adjacent surfaces and their common angle d. The first surface a is the first side surface of the base layer 1, the second surface b includes the first sub-surface b1 and the second sub-surface b2, the first sub-surface b1 being a light-receiving or non-light-receiving surface of the base layer 1, and the second sub-surface b2 being the second side surface adjacent to the first surface, and the triple-pyramid common body is located at the common angle d where the first surface a, the first sub-surface b1 and the second sub-surface b2 are adjacent to each other. The triple-pyramid common body, i.e., the three pyramidal configurations viewed from three different viewpoints, becomes a common body due to the presence of a partially shared triangular surface.

[0050] The following describes the structure of the common elements of the triple pyramid, with further reference to Figures 2 and 5. When viewed in the direction toward the first face a (i.e., along the z-axis direction in Figure 2, toward the first face a), the triple pyramid common body includes a first pyramid structure 111 formed by being enclosed by a first triangular plane 11a and a plurality of third triangular planes 11c; when viewed in the direction toward the light-receiving surface (i.e., along the y-axis direction in Figure 2, toward the light-receiving surface), the triple pyramid common body includes a first type second pyramid 1121 formed by being enclosed by a first type second triangular plane 11b1 and a plurality of third triangular planes 11c; and when viewed in the direction toward the second side (i.e., along the x-axis direction in Figure 2, toward the second side), the triple pyramid common body includes a second type second pyramid 1122 formed by being enclosed by a plurality of second type second triangular planes 11b2 and a plurality of third triangular planes 11c. The first triangular plane 11a means a triangular plane located on the first face a, the first type of second triangular plane 11b1 means a triangular plane located on the first sub-face b1 of the second face b, the second type of second triangular plane 11b2 means a triangular plane located on the second sub-face b2 of the second face b, and the third triangular plane 11c means a triangular plane located on the extended surface of the first face a, the extended surface of the first sub-face b1, and the extended surface of the second sub-face b2, respectively. Therefore, the third triangular plane 11c is a common surface.

[0051] Compared to a configuration of three separate pyramids, a triple pyramid common structure, where the three surfaces are adjacent to each other, has more common surfaces, resulting in a smaller surface area. This is more advantageous in reducing defects in base layer 1 and improving the cleanliness of the base layer 1 surface.

[0052] Furthermore, the solar cell may be a single solar cell or a sliced ​​cell. In the case of a sliced ​​cell, the base layer 1 has a cut surface due to the slicing operation of the solar cell. The side surface of the base layer 1 includes the cut surface. It should be understood that the side surface of the base layer 1 may include the cut surface or other sides. The multi-pyramid common body 11 may be located at a common edge c and / or common angle d shared by the cut surface and the light-receiving surface, non-light-receiving surface or other side surface adjacent to it. Furthermore, after the slicing operation of the solar cell, post-processing such as texturing may be performed on the side surface of the cut area to form the multi-pyramid common body 11 where the cut surface and its adjacent surface are adjacent to each other.

[0053] After slicing a single solar cell, some damage occurs at the cut surface, resulting in more defects and dangling bonds, which tends to exacerbate the problem of recombination at the cut surface. By having a multi-pyramid common body 11 at the common edge c and / or common angle d shared by the cut surface and adjacent surfaces, the problem of increased defects at the cut surface due to the slicing process can be solved more effectively.

[0054] Furthermore, the first face a and the second face b are perpendicular to each other.

[0055] The following is an interpretation and explanation of the composition of each pyramid.

[0056] In the orthographic projection of the first face a, the first pyramidal structure 111 has a first diagonal length L1 such that 0.1 μm ≤ L1 ≤ 7 μm, and in the orthographic projection of the second face b, the second pyramidal structure 112 has a second diagonal length L2 such that 0.1 μm ≤ L2 ≤ 7 μm, and in each multi-pyramid common body 11, 0.5 ≤ L1 / L2 ≤ 2.

[0057] The first diagonal length L1 refers to the average length of the diagonals of the base of the first pyramid configuration 111. For example, if the base of the first pyramid configuration 111 is a rectangle containing two diagonals, the first diagonal length L1 refers to the average length of the two diagonals. Illustratively, L1 is 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 5 μm, or 7 μm. The second diagonal length L2 refers to the average length of the diagonals of the base of the second pyramid configuration 112. Illustratively, L2 is 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 5 μm, or 7 μm. Illustratively, L1 / L2 is 0.5, 0.8, 0.9, 1, 1.1, 1.2, 1.5, or 2.

[0058] When the lengths of the diagonals of the pyramidal structure in two directions are within the range described above, and the ratio between the two is controlled to be within the range described above, the variation in the overall size of the single multi-pyramid common body 11 is reduced. In particular, when the ratio of L1 / L2 is close to 1 (for example, when L1 / L2 is 0.8 to 1.2), it is shown that the uniformity of the overall size of the single multi-pyramid common body 11 is good. This is advantageous for further improving the light utilization rate and is also advantageous for subsequently depositing functional layers such as passivation layers with better adhesion on the base layer 1.

[0059] In a direction perpendicular to the first face a, the first pyramidal structure 111 has a first height H1 such that 0.1 μm ≤ H1 ≤ 3 μm, and in a direction perpendicular to the second face b, the second pyramidal structure 112 has a second height H2 such that 0.1 μm ≤ H2 ≤ 3 μm, and in each multi-pyramid common body 11, 0.5 ≤ H1 / H2 ≤ 2. Exemplarily, H1 is 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, or 3 μm. Exemplarily, H2 is 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, or 3 μm. Exemplarily, H1 / H2 is 0.5, 0.8, 0.9, 1, 1.1, 1.2, 1.5, or 2.

[0060] When the heights of the pyramidal structures in two directions are within the above-mentioned range, and the proportion between them is controlled to be within the above-mentioned range, the variation in the overall height of a single multi-pyramid common structure 11 is reduced. In particular, when the H1 / H2 ratio is close to 1 (for example, when H1 / H2 is between 0.8 and 1.2), it is shown that the uniformity of the overall height of a single multi-pyramid common structure 11 is good. This characteristic of good uniformity of height in different directions and small variation is advantageous in ensuring film deposition quality when a functional layer such as a passivation layer is subsequently deposited on the base layer 1, and in reducing the probability of the functional layer rupturing due to excessive variation in the height of the multi-pyramid common structure 11 in different directions.

[0061] Furthermore, the multi-pyramid common bodies 11 are arranged along the length direction of the common ridge c. The common ridge c has a central region and edge regions located on both sides of the central region. The length of the diagonal of the multi-pyramid common body 11 located in the central region is shorter than the length of the diagonal of the multi-pyramid common body 11 located in the edge regions, and the height of the multi-pyramid common body 11 located in the central region is shorter than the height of the multi-pyramid common body 11 located in the edge regions.

[0062] The multi-pyramid common structure 11 on the common ridge c has the characteristic that the size and height of the part located in the central region are relatively small, while the size and height of the part located in the peripheral region are relatively large. The base layer 1 in the peripheral region is more prone to absorbing dirt than the central region, making it more difficult to solve the cleaning problem. Since the size and height of the multi-pyramid common structure 11 located in the peripheral region are relatively large, it is advantageous to solve the dirt problem of the base layer 1 in the peripheral region and improve the cleanliness.

[0063] For a 100 μm length region of the common ridge c, there is one multiple pyramidal common body 11. Preferably, for a 100 μm length region of the common ridge c, there is at least 10 multiple pyramidal common bodies 11, and preferably 10 to 20.

[0064] The following interpretation and explanation of the pyramidal structure of the first face a and the second face b.

[0065] Referring to Figure 6, the present invention has a multi-pyramid common body 11 at a position where the first face a and the second face b are adjacent to each other, and further has a plurality of third pyramid structures 12 on the first face a and a plurality of fourth pyramid structures 13 on the second face b.

[0066] Since at least one of the first surface a and the second surface b is a side surface of the base layer 1, the presence of the pyramid structure on this surface is advantageous in increasing the efficiency of light absorption and utilization. Furthermore, the placement of the pyramid structure on this surface can work in cooperation with the multi-pyramid common body 11 to improve adhesion when a functional layer (e.g., a passivation layer) is placed on the base layer 1, thereby further enhancing the effectiveness of the functional layer.

[0067] Furthermore, in the orthographic projection of the first surface a, the first pyramidal structure 111 has a first diagonal length L1 such that 0.1 μm ≤ L1 ≤ 7 μm, and the third pyramidal structure 12 has a third diagonal length L3 such that 0.1 μm ≤ L3 ≤ 7 μm and 0.5 ≤ L3 / L1 ≤ 2. The third diagonal length L3 refers to the average value of the diagonal lengths of the base of the third pyramidal structure 12. Exemplarily, L3 is 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 5 μm, or 7 μm. Exemplarily, L3 / L1 is 0.5, 0.8, 0.9, 1, 1.1, 1.2, 1.5, or 2.

[0068] In the orthographic projection of the second face b, the second pyramidal structure 112 has a second diagonal length L2 such that 0.1 μm ≤ L2 ≤ 7 μm, and the fourth pyramidal structure 13 has a fourth diagonal length L4 such that 0.1 μm ≤ L4 ≤ 7 μm and 0.5 ≤ L4 / L2 ≤ 2. The fourth diagonal length L4 refers to the average value of the diagonal lengths of the base face of the fourth pyramidal structure 13. Exemplarily, L4 is 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 5 μm, or 7 μm. Exemplarily, L4 / L2 is 0.5, 0.8, 0.9, 1, 1.1, 1.2, 1.5, or 2.

[0069] When the diagonal lengths and proportions of the first pyramidal structure 111 and the third pyramidal structure 12 are within the above-described range, and the diagonal lengths and proportions of the second pyramidal structure 112 and the fourth pyramidal structure 13 are within the above-described range, the variation in the overall size of the pyramidal structure on the first surface a, on the second surface b, and where the first surface a and the second surface b are adjacent to each other becomes relatively small, demonstrating good uniformity in the overall size of the pyramidal structure at different locations. This reduces the problem of many groove defects occurring between pyramidal structures due to excessive size variation, thereby reducing the risk of increased defects and contamination by impurities.

[0070] Furthermore, in a direction perpendicular to the first surface a, the first pyramidal structure 111 has a first height H1 such that 0.1 μm ≤ H1 ≤ 3 μm, and the third pyramidal structure 12 has a third height H3 such that 0.1 μm ≤ H3 ≤ 5 μm and 0.5 ≤ H3 / H1 ≤ 2. Exemplarily, H3 is 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 3 μm, 4 μm, or 5 μm. Exemplarily, H3 / H1 is 0.5, 0.8, 0.9, 1, 1.1, 1.2, 1.5, or 2.

[0071] In a direction perpendicular to the second face b, the second pyramidal structure 112 has a second height H2 such that 0.1 μm ≤ H2 ≤ 3 μm, and the fourth pyramidal structure 13 has a fourth height H4 such that 0.1 μm ≤ H4 ≤ 5 μm and 0.5 ≤ H4 / H2 ≤ 2. Exemplarily, H4 is 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 3 μm, 4 μm, or 5 μm. Exemplarily, H4 / H2 is 0.5, 0.8, 0.9, 1, 1.1, 1.2, 1.5, or 2.

[0072] When the heights and proportions of the first pyramid configuration 111 and the third pyramid configuration 12 are within the above-mentioned range, and the heights and proportions of the second pyramid configuration 112 and the fourth pyramid configuration 13 are within the above-mentioned range, the variation in the overall height of the pyramid configuration on the first surface a, on the second surface b, and at the points where the first surface a and the second surface b are adjacent to each other becomes relatively small, demonstrating good uniformity in the overall height of the pyramid configuration at different locations.

[0073] The following describes and explains the other configurations of the solar cell of this embodiment.

[0074] The solar cell of the present embodiment is A semiconductor layer located on the light-receiving surface and / or non-light-receiving surface of base layer 1, A passivation layer located on the side opposite to the base layer 1 of the semiconductor layer, and located on the side of the base layer 1, Includes electrodes.

[0075] The electrodes can penetrate the passivation layer and make ohmic contact with the semiconductor layer.

[0076] As a selective embodiment, as shown in Figure 7, the solar cell is a back-contact solar cell. Base layer 1 and A first semiconductor layer 21 and a first electrode 31 are sequentially placed in the P-type conductive region of the non-light-receiving surface of the base layer 1, It includes a second semiconductor layer 22 and a second electrode 32 that are sequentially placed in the N-type conductive region of the non-light-receiving surface of the base layer 1, The first semiconductor layer 21 and the second semiconductor layer 22 are arranged alternately in a cross-finger shape, and there is an isolation region 4 between the first semiconductor layer 21 and the second semiconductor layer 22.

[0077] Furthermore, solar cells, A first passivation layer 51 is provided on the side of the first semiconductor layer 21 opposite to the non-light-receiving surface, A second passivation layer 52 is provided on the side of the second semiconductor layer 22 opposite to the non-light-receiving surface, A third passivation layer 53 is provided on the light-receiving surface of the base layer 1, The present invention further includes a fourth passivation layer 54 provided on the side surface of the base layer 1.

[0078] Since the first semiconductor layer 21 and the second semiconductor layer 22 are each installed on the non-light-receiving side of the base layer 1, it should be understood that the first passivation layer 51 and the second passivation layer 52 may be installed on the first semiconductor layer 21 and the second semiconductor layer 22, respectively, or they may be installed as an integrated passivation layer covering the entire non-light-receiving surface so as to cover the first semiconductor layer 21, the second semiconductor layer 22 and the base layer 1 of the isolation region 4.

[0079] The common ridge line c and / or common angle d of the light-receiving surface and side of the base layer 1 are provided with the multi-pyramid common body 11 having a common surface, and a third pyramid structure 12 is provided on the side, which is advantageous in improving the adhesion effect between the fourth passivation layer 54 installed on the side and the base layer 1, and consequently improving the passivation performance of the fourth passivation layer 54.

[0080] Furthermore, a first medium layer 61 is provided between the base layer 1 and the first semiconductor layer 21, and a second medium layer 62 is provided between the base layer 1 and the second semiconductor layer 22.

[0081] Selectively, the first semiconductor layer 21 is a first doped polysilicon layer or a first doped amorphous silicon layer deposited on the light-receiving surface of the base layer 1, and the second semiconductor layer 22 is a second doped polysilicon layer or a second doped amorphous silicon layer deposited on the medium layer.

[0082] Selectively, the first passivation layer 51 is one or more of an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer; the second passivation layer 52 is one or more of an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer; the third passivation layer 53 is one or more of an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer; and the fourth passivation layer 54 is one or more of an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer.

[0083] Selectively, the first media layer 61 is at least one of a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, and a silicon carbide layer, and the second media layer 62 is at least one of a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, and a silicon carbide layer.

[0084] In another optional embodiment, the solar cell is a passivation contact solar cell. The solar cell is Base layer 1 and A first semiconductor layer 21 and a first electrode 31 are sequentially provided on the light-receiving surface of the base layer 1, It includes a medium layer, a second semiconductor layer 22, and a second electrode 32, which are sequentially provided on the non-light-receiving surface of the base layer 1. The first semiconductor layer 21 and the base layer 1 have different conductivity types.

[0085] The first electrode 31 and the first semiconductor layer 21 are in ohmic contact, and the second electrode 32 and the second semiconductor layer 22 are in ohmic contact.

[0086] Furthermore, solar cells, A fifth passivation layer is provided on the side of the first semiconductor layer 21 opposite to the light-receiving surface, A sixth passivation layer is provided on the side of the second semiconductor layer 22 opposite to the non-light-receiving surface, The present invention further includes a seventh passivation layer provided on the side surface of the base layer 1.

[0087] The common ridge line c and / or common angle d between the light-receiving surface (or non-light-receiving surface) and the side surface of the base layer 1 is provided with the multi-pyramid common body 11 having a common surface, and a third pyramidal structure 12 is provided on the side surface. This is advantageous for improving the adhesion effect between the seventh passivation layer installed on the side surface and the base layer 1, and consequently improves the passivation performance of the seventh passivation layer.

[0088] Selectively, the first semiconductor layer 21 is formed by thermally diffusing a dopant element into the base layer 1, or is a first doped polysilicon layer or a first doped amorphous silicon layer deposited on the light-receiving surface of the base layer 1, and the second semiconductor layer 22 is a second doped polysilicon layer or a second doped amorphous silicon layer deposited on the medium layer.

[0089] Selectively, the fifth passivation layer is one or more of the following: an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer; the sixth passivation layer is one or more of the following: an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer; and the seventh passivation layer is one or more of the following: an aluminum oxide layer, a silicon oxide layer, a silicon oxide nitride layer, or a silicon nitride layer.

[0090] Selectively, the media layer is at least one of the following: a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, or a silicon carbide layer.

[0091] The embodiments of this application further provide the method for manufacturing the solar cell described above. It should be understood that the solar cell of the embodiments of this application can also be obtained by other manufacturing methods, and this application is not limited thereto.

[0092] The following description will be based on the example of fabricating a back-contact solar cell having the above-described base layer. This embodiment provides a method for fabricating a back-contact solar cell, and includes the following steps.

[0093] First polishing session The silicon substrate is pre-treated with a mixed solution of alkali and additives to remove surface line marks and oil stains. The alkaline solution contains 0.6% wt to 4.8% wt of NaOH or KOH and 0.9% wt to 1.1% wt of additives, with a polishing temperature of 50 to 90°C and a polishing time of 400 to 900 seconds. After polishing, deep cleaning is performed with a mixed solution of hydrofluoric acid and hydrochloric acid, followed by thorough rinsing with deionized water, and finally a drying treatment is carried out.

[0094] First deposition At a deposition temperature of 540°C to 660°C, a silicon oxide layer with a thickness of 0.6 nm to 2.8 nm, which serves as the first medium layer, and an intrinsic amorphous silicon layer with a thickness of 120 nm to 280 nm are sequentially deposited on the non-light-receiving surface of the substrate layer by LPCVD, preferably a 2 nm silicon oxide layer and a 250 nm intrinsic amorphous silicon layer are deposited.

[0095] The intrinsic amorphous silicon layer is doped using a thermal diffusion method, converting it into a first doped crystalline silicon layer. The doping type is the opposite of the doping type of the silicon substrate. For example, if the silicon substrate is an N-type silicon substrate, the intrinsic amorphous silicon layer is doped with a boron source using the thermal diffusion method, thereby obtaining a boron-doped crystalline silicon layer as the first doped crystalline silicon layer. After doping is complete, a first doped silicon oxide mask is formed on the surface of the first doped crystalline silicon layer, with a thickness of 18-62 nm.

[0096] First pattern The first doped silicon oxide mask is opened by laser etching until the first doped crystalline silicon layer is exposed on the non-light-receiving side of the silicon substrate, thereby obtaining a patterned first doped silicon oxide mask. The conditions for laser etching are: (1) the type of laser includes at least one of nanosecond, picosecond, or femtosecond wavelengths; (2) the wavelength of the laser is selected from infrared, visible light, or ultraviolet lasers; and (3) the laser energy is 30-3000 mJ / cm². 2 (4) The wavelength range is 700 to 1000 nm, and (5) The shape of the laser spot includes circular, square, rectangular, and elliptical shapes.

[0097] Second polishing Etching with an alkaline solution removes the first doped crystalline silicon layer and the first medium layer corresponding to the laser irradiation area until the silicon substrate is exposed (in this process, the underlying film layer is preserved by the protection of a patterned doped silicon oxide mask). The alkaline solution contains 0.5% wt to 5% wt of NaOH or KOH and 0.9% wt to 1.1% wt of additives mainly consisting of sodium gluconate, a protective agent, and a brightener. The processing temperature is 65 to 85°C, and the polishing time is 300 to 800 seconds. After the second polishing is complete, alkaline cleaning with the alkaline solution and water cleaning are performed sequentially, followed by acid cleaning with the acid solution, water cleaning, and drying.

[0098] Second deposition Using the PECVD method, a second medium layer with a thickness of 1.5 nm, a second doped amorphous silicon layer with a thickness of 200 nm, and a second doped silicon oxide mask are sequentially deposited on a non-photosensitive surface. Through annealing, the second doped amorphous silicon layer is converted into a second doped polysilicon layer. The thickness of the second doped silicon oxide mask is 20 nm to 60 nm.

[0099] Patterning for the second time On the non-light-receiving side, the majority of the second doped silicon oxide mask is removed by laser etching until the second doped polysilicon layer is exposed (the removal area includes the area corresponding to the first doped crystalline silicon layer and the area for forming the groove region). The conditions for laser etching are: (1) the laser type includes at least one of nanosecond, picosecond, or femtosecond lasers; (2) the laser wavelength is selected from infrared, visible light, or ultraviolet lasers; and (3) the laser energy is 30-3000 mJ / cm². 2 This includes (4) being controlled internally, and (5) having a wavelength range of 700 to 1000 nm, and (6) having laser spot dimensions of (20 to 400) μm * (20 to 400) μm.

[0100] Acid polishing and texturing The light-receiving surface is polished with acid. A chain-type machine is used as the acid polishing machine station, and a mixed acid solution of hydrofluoric acid, nitric acid, and sulfuric acid is used to corrode and remove the mask layer of the light-receiving surface. In addition, the sides of the silicon wafer may corrode as the chemical solution rises and reacts with the mask layer due to the capillary adsorption effect during acid polishing. Therefore, acid polishing removes all of the plating layer and doped silicon oxide mask from the light-receiving surface and sides, exposing the base layer of the light-receiving surface and sides. In this process, before acid polishing, a water film is sprayed onto the non-light-receiving surface to protect the film layer on the non-light-receiving surface from corrosion during the acid polishing process of the light-receiving surface and sides.

[0101] Texturing In the texturing process, due to the difference in corrosion rates by the alkaline solution between the surface of the silicon wafer (100) and the surface of the first pyramidal structure (111), a third pyramidal structure and a fourth pyramidal structure are formed on the side surface and the light-receiving surface, respectively, and a multi-pyramid common structure is formed where the light-receiving surface and the side surface are adjacent to each other. In texturing, an alkaline solution and a texturing additive are used. The alkaline aqueous solution is KOH or NaOH, and its concentration is controlled within the range of 1 to 5 wt%. The texturing additive has a concentration of 0.5 to 2 wt% and its main components include carboxymethylcellulose, sodium ligninsulfonate, and an antifoaming agent. In the texturing additive, carboxymethylcellulose is 1 wt%, sodium ligninsulfonate is 1 wt%, and the antifoaming agent is 0.5 wt%. The texturing operation temperature is set to 60 to 85°C, and the texturing time is set to 300 to 800 seconds.

[0102] Alkaline cleaning, water cleaning, acid cleaning, water cleaning, drying After texturing is complete, the silicon wafer is cleaned by alkaline cleaning with a mixed solution of KOH and H2O2 or a mixed solution of NaOH and H2O2 to remove any additives remaining from the texturing process. In acid cleaning, the first doped silicon oxide mask and the second doped silicon oxide mask on the non-photosensitive surface are removed with an HF solution.

[0103] Third deposition Using PECVD, aluminum oxide layers are deposited to a thickness of 4 nm on the light-receiving surface, side surfaces, and non-light-receiving surfaces, and then a silicon nitride layer is deposited to serve the purpose of passivation and anti-reflection. The silicon nitride layer on the light-receiving surface is 75 nm thick, the silicon nitride layer on the non-light-receiving surface is 92 nm thick, and the silicon nitride layer on the side surfaces is 167 nm thick.

[0104] Electrodes are formed by screen printing and sintering.

[0105] In the solar cell obtained by the method described above, the light-receiving surface of the base layer has multiple fourth pyramidal structures, the side surface has multiple third pyramidal structures, and the common ridge line where the light-receiving surface and the side surface are adjacent to each other has multiple multi-pyramidal commonalities. From the scanning electron microscope images in Figures 8 and 9, these multi-pyramidal commonalities can be seen, specifically at an angle toward the cross-section side surface. Figure 8 shows the central region of the common ridge line from the viewpoint of the cross-section side surface, and Figure 9 shows the edge region of the common ridge line from the viewpoint of the cross-section side surface.

[0106] Furthermore, in the manufacturing method of the embodiment of the present invention, slicing of the semi-finished solar cell may be performed before the texturing step, and then texturing and subsequent operations may be carried out. Exemplarily, in combination with the manufacturing method described above, slicing may be performed after acid polishing of the light-receiving surface and before texturing, or slicing may be performed after the second patterning step and before the step of acid polishing of the light-receiving surface. By slicing the manufactured semi-finished solar cell, at least one side of the base layer can be made into a cut surface. In the final solar cell, there are multiple multi-pyramid commons on the common ridges where the light-receiving surface and the side are adjacent to each other, there are also multiple multi-pyramid commons on the common ridges of adjacent side surfaces, and there are triple pyramid commons at the common angles where the light-receiving surface and two adjacent side surfaces are adjacent to each other.

[0107] In a second embodiment, the present invention further provides a photovoltaic module including the solar cell described in the first embodiment.

[0108] The following will provide a more detailed explanation based on specific examples and test data.

[0109] Example 1 This embodiment provides a solar cell, N-type silicon substrate and A first medium layer, a boron-doped polysilicon layer, a first semiconductor layer, and a first electrode are sequentially placed in the N-type conductive region of the non-photosensitive surface of the base layer. A second medium layer, a phosphorus-doped polysilicon layer, a second semiconductor layer, and a second electrode are sequentially placed in the P-type conductive region of the non-photosensitive surface of the base layer. A first passivation layer is provided on the side of the first semiconductor layer opposite to the non-light-receiving surface, A second passivation layer is provided on the side of the second semiconductor layer opposite to the non-light-receiving surface, A third passivation layer is provided on the light-receiving surface of the base layer, It includes a fourth passivation layer provided on the side of the base layer, The first semiconductor layer and the second semiconductor layer are arranged alternately in a cross-finger pattern, and there is an isolated region between the first semiconductor layer and the second semiconductor layer. The first passivation layer and the second passivation layer are full-layer structures, with the first electrode penetrating the first passivation layer and making ohmic contact with the first semiconductor layer, and the second electrode penetrating the second passivation layer and making ohmic contact with the second semiconductor layer.

[0110] The base layer has adjacent light-receiving surfaces and sides, the sides have multiple third pyramidal structures, the light-receiving surfaces have multiple fourth pyramidal structures, and along the common ridges where the light-receiving surfaces and sides of the base are adjacent to each other, a multi-pyramid common body having a common surface is further provided.

[0111] When viewed from the side, the multi-pyramid common body has a first pyramidal configuration formed by being enclosed by a plurality of first triangular planes and a plurality of third triangular planes. When viewed towards the light-receiving surface, the multi-pyramid common body has a second pyramidal configuration formed by being enclosed by a plurality of second triangular planes and a plurality of the aforementioned third triangular planes. The third triangular plane is a common plane and is a triangular plane, triangle, or quasi-triangular plane among the first, second, and third triangular planes.

[0112] In the orthographic projection of the side, the first pyramidal structure has a first diagonal length L1, where L1 is between 0.1 μm and 7 μm. In the orthographic projection of the light-receiving surface, the second pyramidal structure has a second diagonal length L2, where L2 is between 0.1 μm and 7 μm. In each common pyramidal structure, 0.5 ≤ L1 / L2 ≤ 2.

[0113] In the direction perpendicular to the side, the first pyramidal structure has a first height H1, where H1 is between 0.1 μm and 3 μm. In the direction perpendicular to the light-receiving surface, the second pyramidal structure has a second height H2, where H2 is between 0.1 μm and 3 μm. In each common pyramidal structure, 0.5 ≤ H1 / H2 ≤ 2.

[0114] In the region corresponding to a common ridge length of 100 μm, the number of multi-pyramid commonalities is one or more.

[0115] In the orthographic projection of the side, the third pyramidal structure has a third diagonal length L3, where L3 is between 0.1 μm and 7 μm, and 0.5 ≤ L3 / L1 ≤ 2. In the orthographic projection of the light-receiving surface, the fourth pyramidal structure has a fourth diagonal length L4, where L4 is between 0.1 μm and 7 μm, and 0.5 ≤ L4 / L2 ≤ 2.

[0116] In the direction perpendicular to the side, the third pyramidal structure has a third height H3, where H3 is between 0.1 μm and 3 μm, and 0.5 ≤ H3 / H1 ≤ 2. In the direction perpendicular to the light-receiving surface, the fourth pyramidal structure has a fourth height H4, where H4 is between 0.1 μm and 3 μm, and 0.5 ≤ H4 / H2 ≤ 2.

[0117] Example 2 The difference between this embodiment and Embodiment 1 is that the solar cell is a slice solar cell, and a cut surface is formed at the cutting position.

[0118] In addition to the common ridges between the cut surfaces and the light-receiving surfaces, the common ridges between the cut surfaces and their adjacent surfaces, and the base layer, which are provided with a double pyramidal common body having a common surface, a triple pyramidal common body having a common surface is further provided at the common angles between the cut surfaces, the light-receiving surfaces, and the surfaces adjacent to the cut surfaces of the base layer.

[0119] Comparative Example 1 The difference between this comparative example and Example 1 is that the solar cell has a fourth pyramidal structure only on its light-receiving surface, and does not have a third pyramidal structure or a common multi-pyramid structure on its sides.

[0120] Comparative Example 2 The difference between this comparative example and Example 1 is that the solar cell has a third pyramidal structure only on its side surface and a fourth pyramidal structure on its light-receiving surface, but does not have a common structure for multiple pyramidal structures.

[0121] Performance testing The HALM test sorting system is used to perform performance tests such as open-circuit voltage, fill factor, and photoelectric conversion efficiency. The HALM system is a solar simulation system that works in conjunction with electronic loads, data acquisition, and calculation equipment to measure the electrical performance of photovoltaic elements (including solar cells). The silicon wafers for solar cells under test are controlled to size 182, and the calibration light intensity is set to 1000 ± 5 W / m2.

[0122] The test results are shown in Table 1 below. Table 1 Test results for Examples 1-2 and Comparative Examples 1-2 TIFF2026053248000002.tif44140

[0123] Comparing the test results of Example 1 and Comparative Examples 1 and 2, it can be seen that when a pyramidal structure is provided on adjacent surfaces of the base layer, and a multi-pyramid common body with a common surface is provided on the common ridge of the adjacent surfaces, the photoelectric conversion efficiency of the solar cell is improved by 0.1% or more. In the field of solar cell technology, an improvement of 0.1% or more means that the solar cell has greater practical value when assembled and used in a photovoltaic module. As can be seen from the above, the solar cell of the present embodiment is advantageous for further improvement of battery performance due to the presence of the multi-pyramid common body.

[0124] Furthermore, comparing Example 1 and Example 2, the multi-pyramid common structure formed at the cutting position after slicing the battery includes both double-pyramid common structures and triple-pyramid common structures, and the characteristics of this configuration are advantageous for further improving the performance of the solar cell.

[0125] The technical modes disclosed in the present invention have been described in detail above, and the principles and embodiments of the present invention have been explained by applying specific examples. However, the above description of the examples is merely intended to facilitate understanding of the technical modes and the core of the invention of the present invention. Furthermore, those skilled in the art can modify the specific embodiments and scope of application in accordance with the spirit of the present invention, and therefore, the contents of this specification should not be interpreted as limitations of the present invention.

[0126] Explanation of the symbols 1 Base layer, a First face, b Second face, b1 First sub-face, b2 Second sub-face, c Common ridge, d Common angle, 11 Multiple pyramid common body, 111 First pyramid configuration, 112 Second pyramid configuration, 1121 First type of second pyramid, 1122 Second type of second pyramid, 12 Third pyramid configuration, 13 Fourth pyramid configuration, 11a First triangular plane, 11b Second triangular plane, 11b1 First type of second triangular plane, 11b2 Second type of second triangular plane, 11c Third triangular plane 21 First semiconductor layer, 22 Second semiconductor layer, 31 First electrode, 32 Second electrode, 4 Isolation region, 51 First passivation layer, 52 Second passivation layer, 53 Third passivation layer, 54 Fourth passivation layer, 61 First medium layer, 62 Second medium layer.

Claims

1. It is a solar cell, The base layer includes a base layer having a first surface and a second surface adjacent to each other, and at least one of the first surface and the second surface being a side surface of the base layer. At the common ridge and / or common angle where the first face and the second face are adjacent to each other, a multi-pyramid common body having a common face is provided in the base layer. A solar cell characterized in that, when viewed toward the first face, the multi-pyramid common body includes a first pyramidal structure formed by being enclosed by a plurality of first triangular planes and a plurality of third triangular planes, and when viewed toward the second face, the multi-pyramid common body includes a second pyramidal structure formed by being enclosed by a plurality of second triangular planes and a plurality of the third triangular planes, the third triangular plane being the common face, and the triangular planes among the first triangular plane, the second triangular plane, and the third triangular plane being triangles or quasi-triangulars.

2. The aforementioned multi-pyramid common body is a double pyramid common body, The solar cell according to claim 1, characterized in that the first surface is a first side surface of the base layer, the second surface includes a first sub-surface, the first sub-surface is either a light-receiving surface, a non-light-receiving surface, or a second side surface of the base layer, and the double pyramidal common body is provided on the common ridge line located adjacent to the first surface and the first sub-surface.

3. The aforementioned multi-pyramid commonality is a triple-pyramid commonality, The solar cell according to claim 1, characterized in that the first surface is a first side surface of the base layer, the second surface includes a first sub-surface and a second sub-surface, the first sub-surface being a light-receiving surface or a non-light-receiving surface of the base layer, the second sub-surface being a second side surface adjacent to the first side surface, and the triple pyramid common body is provided at the common angle located adjacent to the first surface, the first sub-surface and the second sub-surface.

4. The solar cell is a slice cell, the base layer has a cut surface, the surface of the base layer includes the cut surface, and / or The solar cell according to claim 1, characterized in that the first surface and the second surface are perpendicular to each other.

5. In the orthographic projection of the first surface, the first pyramidal structure has a first diagonal length L1, where 0.1 μm ≤ L1 ≤ 7 μm. In the orthographic projection of the second surface, the second pyramidal structure has a second diagonal length L2, where 0.1 μm ≤ L2 ≤ 7 μm. The solar cell according to claim 1, characterized in that in any of the multiple pyramidal common bodies, 0.5 ≤ L1 / L2 ≤ 2.

6. In a direction perpendicular to the first surface, the first pyramidal structure has a first height H1, where 0.1 μm ≤ H1 ≤ 3 μm. In a direction perpendicular to the second surface, the second pyramidal structure has a second height H2, where 0.1 μm ≤ H2 ≤ 3 μm. The solar cell according to claim 1, characterized in that in any of the multiple pyramidal common bodies, 0.5 ≤ H1 / H2 ≤ 2.

7. The aforementioned multi-pyramid common elements are arranged along the longitudinal direction of the common ridge line, The solar cell according to claim 1, characterized in that the common ridge has a central region and edge regions located on both sides of the central region, the length of the diagonal of the multi-pyramid common body located in the central region is smaller than the length of the diagonal of the multi-pyramid common body located in the edge region, the height of the multi-pyramid common body located in the central region is smaller than the height of the multi-pyramid common body located in the edge region, and / or the number of multi-pyramid common bodies is one or more corresponding to a 100 μm length region of the common ridge.

8. The solar cell according to claim 7, characterized in that the number of the multiple pyramidal common bodies is at least 10, corresponding to a region of 100 μm in length along the common ridge.

9. The solar cell according to any one of claims 1 to 8, characterized in that the first surface has a plurality of third pyramidal structures, and the second surface has a plurality of fourth pyramidal structures.

10. In the orthographic projection of the first surface, the first pyramidal structure has a first diagonal length L1 such that 0.1 μm ≤ L1 ≤ 7 μm, and the third pyramidal structure has a third diagonal length L3 such that 0.1 μm ≤ L3 ≤ 7 μm and 0.5 ≤ L3 / L1 ≤ 2. The solar cell according to claim 9, characterized in that, in the orthographic projection of the second surface, the second pyramidal structure has a second diagonal length L2 such that 0.1 μm ≤ L2 ≤ 7 μm, and the fourth pyramidal structure has a fourth diagonal length L4 such that 0.1 μm ≤ L4 ≤ 7 μm and 0.5 ≤ L4 / L2 ≤ 2.

11. In a direction perpendicular to the first surface, the first pyramidal structure has a first height H1 such that 0.1 μm ≤ H1 ≤ 3 μm, and the third pyramidal structure has a third height H3 such that 0.1 μm ≤ H3 ≤ 5 μm and 0.5 ≤ H3 / H1 ≤ 2. The solar cell according to claim 9, characterized in that, in a direction perpendicular to the second surface, the second pyramidal structure has a second height H2, wherein 0.1 μm ≤ H2 ≤ 3 μm, and the fourth pyramidal structure has a fourth height H4, wherein 0.1 μm ≤ H4 ≤ 5 μm and 0.5 ≤ H4 / H2 ≤ 2.

12. The aforementioned solar cell is A semiconductor layer located on the light-receiving surface and / or non-light-receiving surface of the base layer, A passivation layer located on the side of the semiconductor layer opposite to the base layer and on the side of the base layer, A solar cell according to any one of claims 1 to 8, 10 to 11, further comprising electrodes.

13. The aforementioned solar cell is The aforementioned base layer, A first semiconductor layer and a first electrode are sequentially placed in the P-type conductive region of the non-light-receiving surface of the base layer, The substrate includes a second semiconductor layer and a second electrode, which are sequentially placed in the N-type conductive region of the non-light-receiving surface of the substrate. The solar cell according to claim 12, characterized in that the first semiconductor layer and the second semiconductor layer are arranged alternately in a cross-finger shape, and there is an isolation region between the first semiconductor layer and the second semiconductor layer.

14. The aforementioned solar cell is A first passivation layer provided on the side of the first semiconductor layer opposite to the substrate layer, A second passivation layer provided on the side of the second semiconductor layer opposite to the substrate layer, A third passivation layer provided on the light-receiving surface of the base layer, The solar cell according to claim 13, further comprising a fourth passivation layer provided on the side surface of the base layer.

15. The solar cell according to claim 14, characterized in that a first medium layer is further provided between the base layer and the first semiconductor layer, and a second medium layer is further provided between the base layer and the second semiconductor layer.

16. The first semiconductor layer is a first doped polysilicon layer or a first doped amorphous silicon layer deposited on the non-photosensitive surface of the substrate layer, and the second semiconductor layer is a second doped polysilicon layer or a second doped amorphous silicon layer deposited on the second medium layer, and / or The first passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the second passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the third passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the fourth passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; and / or The first media layer is at least one layer selected from a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, and a silicon nitride layer, and the second media layer is at least one layer selected from a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, and a silicon nitride layer. The solar cell according to claim 15, characterized in that

17. The aforementioned solar cell is The aforementioned base layer, A first semiconductor layer and a first electrode are sequentially provided on the light-receiving surface of the base layer, The material includes a medium layer, a second semiconductor layer, and a second electrode, which are sequentially provided on the non-light-receiving surface of the base layer. The solar cell according to claim 12, characterized in that the first semiconductor layer has a different conductivity type than the substrate layer.

18. The aforementioned solar cell is A fifth passivation layer provided on the side of the first semiconductor layer opposite to the substrate layer, A sixth passivation layer provided on the side of the second semiconductor layer opposite to the substrate layer, The solar cell according to claim 17, further comprising a seventh passivation layer provided on the side surface of the base layer.

19. The first semiconductor layer is formed by thermally diffusing a dopant element into the substrate layer, or the first semiconductor layer is a first doped polysilicon layer or a first doped amorphous silicon layer deposited on the light-receiving surface of the substrate layer, and / or the second semiconductor layer is a second doped polysilicon layer or a second doped amorphous silicon layer deposited on the medium layer, and / or The fifth passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the sixth passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers; the seventh passivation layer is one or more layers selected from aluminum oxide layers, silicon oxide layers, silicon oxide nitride layers, or silicon nitride layers, and / or The solar cell according to claim 18, characterized in that the media layer is at least one layer selected from a silicon oxide layer, an amorphous silicon layer, a polysilicon layer, and a silicon carbide layer.

20. A photovoltaic module characterized by including a solar cell according to any one of claims 1 to 8.

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