Solar cells and solar modules

Abstract

This improves the light confinement effect on at least one surface of the solar cell and further improves the bifacial coefficient of the solar cell. [Solution] The solar cell includes a semiconductor substrate, a tunnel oxide layer located on at least one surface of the semiconductor substrate, and a doped polycrystalline silicon layer located on a surface of the tunnel oxide layer away from the semiconductor substrate, wherein at least a portion of the surface of the doped polycrystalline silicon layer away from the tunnel oxide layer has silicon-containing protruding particles. The solar module includes the above-described solar cell. Silicon-containing protruding particles are formed on at least a portion of the surface of the doped polycrystalline silicon layer away from the tunnel oxide layer.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application is filed on September 13, 2024, with application number 202411287736.1, and the title of the invention is solar cell and solar module. and an application with a filing date of October 31, 2024, application number 202411546430.3, and a title of invention of solar cell and solar module. Claiming priority, Rera All the contents described in the prior application are incorporated into this application by reference.

[0002] At least one embodiment of this application relates to a solar cell, and more particularly to a solar cell and a solar module. [Background technology]

[0003] The tunnel oxide passivation contact structure (TOPCon structure) consists of an ultrathin tunnel oxide layer and a doped polycrystalline silicon layer. This structure can be applied to various types of batteries, and different types of batteries can be formed, such as TOPCon solar cells, localized TOPCon solar cells, tunnel back-contact solar cells (TBC solar cells), or back-contact solar cells (BC solar cells) having a TOPCon structure in one region.

[0004] Before performing the high-temperature thin-film deposition process, the surface of the silicon substrate is polished using an etching process. During polishing, a rough, uneven structure is formed on the surface of the silicon substrate. While this uneven structure is advantageous for forming good tunnel passivation contacts after depositing the tunnel oxide layer and the polycrystalline silicon thin film, it reduces the light confinement effect on the cell surface, resulting in a lower bifacial coefficient for the solar cell. [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of this, this application provides a solar cell and a solar module in order to improve the bifacial coefficient of a solar cell. [Means for solving the problem]

[0006] According to an embodiment of one aspect of this application, a solar cell is provided comprising a semiconductor substrate, a tunnel oxide layer located on at least one surface of the semiconductor substrate, and a doped polycrystalline silicon layer located on a surface of the tunnel oxide layer away from the semiconductor substrate, wherein at least a portion of the surface of the doped polycrystalline silicon layer away from the tunnel oxide layer has silicon-containing protruding particles.

[0007] According to the embodiments of this application, silicon-containing protruding particles are provided on the surface of a doped polycrystalline silicon layer located near at least one corner or one side of the semiconductor substrate.

[0008] According to the embodiments of this application, the surface of the doped polycrystalline silicon layer, away from the tunnel oxide layer, further has a plurality of undulating structures, and the height of the silicon-containing protrusions is greater than the height of the undulating structures.

[0009] According to embodiments of this application, the doped polycrystalline silicon layer comprises a plurality of first doped polycrystalline silicon layers and a plurality of second doped polycrystalline silicon layers distributed alternately at intervals in a first direction, wherein one of the first doped polycrystalline silicon layers and the second doped polycrystalline silicon layer is N-type and the other of the first doped polycrystalline silicon layer and the second doped polycrystalline silicon layer is P-type, and silicon-containing protruding particles are present on the surface of the first doped polycrystalline silicon layer and / or the second doped polycrystalline silicon layer.

[0010] According to embodiments of this application, at least one surface of a semiconductor substrate has a non-pyramidal texture structure, the non-pyramidal texture structure comprises a plurality of substructures, the doped polycrystalline silicon layer on the apex of the substructure has silicon-containing protruding particles, the distribution density of silicon-containing protruding particles in the N-type doped polycrystalline silicon layer located on the apex of the substructure is greater than the distribution density of silicon-containing protruding particles in the P-type doped polycrystalline silicon layer located on the apex of the substructure.

[0011] According to embodiments of this application, at least one surface of a semiconductor substrate has a non-pyramidal texture structure, the non-pyramidal texture structure comprises a plurality of substructures, the doped polycrystalline silicon layer on the top surface of the substructure has silicon-containing protruding particles, and the distribution density of the silicon-containing protruding particles in the doped polycrystalline silicon layer on the top surface of at least one substructure is 0.1 to 0.5 particles / μm 2 That is the case.

[0012] According to the embodiments of this application, for the same cross-sectional length, the number of protruding particles is smaller than the number of undulating structures.

[0013] According to the embodiments of this application, the above-mentioned solar cell is The doped polycrystalline silicon layer further comprises a passivation anti-reflective layer located on the surface away from the semiconductor substrate, wherein the height of the silicon-containing protrusions is greater than the thickness of the passivation anti-reflective layer, and / or the height of the silicon-containing protrusions is less than three times the thickness of the passivation anti-reflective layer.

[0014] In some embodiments, the doped polycrystalline silicon layer comprises a plurality of first doped polycrystalline silicon layers and a plurality of second doped polycrystalline silicon layers distributed alternately in a first direction, wherein one of the first doped polycrystalline silicon layers and the second doped polycrystalline silicon layer is N-type, and the other of the first doped polycrystalline silicon layer and the second doped polycrystalline silicon layer is P-type. The N-type doped polycrystalline silicon layer has a plurality of depression structures on at least a portion of its surface away from the tunnel oxide layer, and / or the P-type doped polycrystalline silicon layer has a plurality of depression structures on at least a portion of its surface away from the tunnel oxide layer.

[0015] In some embodiments, at least one surface of the semiconductor substrate has a non-pyramidal texture structure, the non-pyramidal texture structure comprises multiple substructures, the doped polycrystalline silicon layer on the apex of the substructures has multiple depression structures, and the distribution density of depression structures located on the apex of the substructures is 50,000 / mm². 2 ~300000 pieces / mm 2 That is the case.

[0016] In some embodiments, at least one surface of the semiconductor substrate has a non-pyramidal texture structure, and the non-pyramidal texture structure includes a plurality of sub-structures. It has a plurality of recessed structures on the surface away from the tunnel oxide layer of the N-type doped polycrystalline silicon layer on the top surface of at least some of the sub-structures, and has a plurality of recessed structures on the surface away from the tunnel oxide layer of the P-type doped polycrystalline silicon layer on the top surface of at least some of the sub-structures. The distribution density of the recessed structures of the N-type doped polycrystalline silicon layer located on the top surface of the sub-structure is greater than the distribution density of the recessed structures of the P-type doped polycrystalline silicon layer located on the top surface of the sub-structure.

[0017] In some embodiments, the above solar cell further includes a passivation antireflection layer located on the surface away from the semiconductor substrate of the doped polycrystalline silicon layer. The passivation antireflection layer is filled in the recessed structure.

[0018] According to the embodiments of the present application, the silicon-containing protrusion particles include at least one of C element, N element and O element.

[0019] According to the embodiments of the present application, the silicon-containing protrusion particles include an element of Group III and / or an element of Group V.

[0020] According to the embodiments of the present application, the height of the silicon-containing protrusion particles is in the range of 150 nm to 450 nm. The length of the undulating structure in the direction parallel to the surface of the semiconductor substrate 1 is 70 nm to 500 nm. The height of the undulating structure is 20 nm to 60 nm.

[0021] According to the embodiments of another aspect of the present application, a solar module including the above solar cell is provided.

[0022] According to an embodiment of the present application, the solar module includes ribbons for electrically connecting two adjacent solar cells, and there is a gap between the ribbons and a doped polycrystalline silicon layer having silicon-containing protrusion particles in the planar direction of at least one surface of the semiconductor substrate.

[0023] According to the solar cell provided in the above embodiment of the present application, silicon-containing protrusion particles are formed on at least a part of the surface of the doped polycrystalline silicon layer away from the tunnel oxide layer, thereby improving the light confinement effect on at least one surface of the solar cell and further improving the bifaciality coefficient of the solar cell.

Brief Description of Drawings

[0024] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments are briefly introduced below. Of course, the drawings in the following description relate only to some embodiments of the present application and do not limit the present application.

[0025] [Figure 1] It is a cross-sectional schematic view of a back-contact solar cell according to an embodiment of the present application. [Figure 2] It is a scanning electron microscope image of the surface of a doped polycrystalline silicon layer close to the edge of a semiconductor substrate according to an embodiment of the present application. [Figure 3] It is another scanning electron microscope image of the surface of a doped polycrystalline silicon layer close to the edge of a semiconductor substrate according to an embodiment of the present application. [Figure 4A] It is yet another scanning electron microscope image of the surface of a doped polycrystalline silicon layer close to the edge of a semiconductor substrate according to an embodiment of the present application. [Figure 4B] It is a test diagram of the height of the surface of the doped polycrystalline silicon layer in FIG. 4A provided in an embodiment of the present application. [Figure 5] It is yet another scanning electron microscope image of the surface of a doped polycrystalline silicon layer close to the edge of a semiconductor substrate according to an embodiment of the present application. [Figure 6] It is a scanning electron microscope image in side view of the surface of a doped polycrystalline silicon layer close to the edge of a semiconductor substrate according to an embodiment of the present application. [Figure 7] This is a schematic cross-sectional view of the TOPCon solar cell according to an embodiment of this application. [Figure 8] This is yet another scanning electron microscope image of the surface of the doped polycrystalline silicon layer adjacent to the edge of the semiconductor substrate in the embodiment of this application. [Figure 9A] This is a scanning electron microscope image of a portion of the area shown in Figure 8. [Figure 9B] This is a diagram showing the results of one EDS test in Figure 9A. [Modes for carrying out the invention]

[0026] To further clarify the purpose, technical solutions, and merits of this application, the application will be described in more detail below with reference to the drawings in conjunction with specific embodiments. However, this application can be implemented in different forms and should not be construed as being limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to make this application thorough and comprehensive and to fully communicate its scope to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions and relative dimensions may be exaggerated, and the same reference numerals in the drawings represent the same elements from beginning to end.

[0027] The terms used herein are for illustrative purposes only and are not intended to limit this application. Terms such as “includes” and “contains” as used herein indicate the presence of such features, steps, operations and / or components, but do not preclude the presence or addition of one or more other features, steps, operations or components.

[0028] In related technologies, we approach the improvement of the bifacial coefficient of solar cells from two angles: surface topography optimization and grid line design. From the perspective of surface topography optimization, we primarily control the polishing effect to create finer surface topography with greater height differences between adjacent layers on the semiconductor substrate (silicon substrate). While this method can improve the light confinement effect on the battery surface, finer surface topography with greater height differences tends to reduce the uniformity of the subsequent deposited thin films (tunnel oxide layer and polycrystalline silicon layer), further causing tunneling, passivation, and contact problems. From the perspective of grid line design, we primarily narrow the width of the busbars and fingers. While this method can improve light absorption, the increased aspect ratio of the grid lines places greater demands on paste moldability. At the same time, finer grid lines also increase the contact resistance of the battery cells.

[0029] In light of this, there is a need to provide solar cells and solar modules to address the technical problem of the urgent need for improved bifacial coefficients in related technologies for solar cells.

[0030] Figure 1 is a schematic cross-sectional view of a back-contact solar cell provided in an embodiment of this application.

[0031] According to one exemplary embodiment of this application, as shown in Figure 1 or Figure 5, Semiconductor substrate 1, A tunnel oxide layer 2 located on at least one surface of a semiconductor substrate 1, The present invention provides a solar cell comprising a doped polycrystalline silicon layer 3 located on a surface of the tunnel oxide layer 2 away from the semiconductor substrate 1, wherein at least a portion of the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2 has silicon-containing protruding particles.

[0032] According to the embodiment of this application, as shown in Figure 1, the solar cell is, for example, a back-contact solar cell. The semiconductor substrate 1 has opposite first and second surfaces, and the tunnel oxide layer 2 is located on the second surface of the semiconductor substrate 1, and in this embodiment, the second surface is the back surface of the back-contact solar cell.

[0033] In some embodiments, the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2 further has multiple undulating structures, and the height of the silicon-containing protrusions is greater than the height of the undulating structures.

[0034] In some embodiments, the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2 further has multiple undulating structures, and the width of the silicon-containing protruding particles is smaller than the width of the undulating structures.

[0035] According to the embodiments of this application, the undulating structure may be, for example, silicon crystal particles. The length of the undulating structure in the direction parallel to the surface of the semiconductor substrate 1 is 70 nm to 500 nm, for example, 70 nm, 100 nm, 150 nm, 200 nm, and 500 nm. The height of the undulating structure is 20 nm to 60 nm, for example, 20 nm, 30 nm, 40 nm, 50 nm, and 60 nm.

[0036] According to the embodiments of this application, the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2 has multiple undulation structures, and the height of the undulation structures is generally small, that is, the degree of undulation of the undulation structures is too gentle, making it difficult to improve the light confinement effect with the undulation structures, and the contribution of the undulation structures to the bifacial coefficient of the battery is limited.

[0037] According to the embodiments of this application, the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2 has multiple undulation structures, and the width of the undulation structures is generally wide, i.e., the degree of undulation of the undulation structures is too gentle, making it difficult to improve the light confinement effect by the undulation structures, and the contribution of the undulation structures to the bifacial coefficient of the battery is limited. This application improves the light confinement effect of the doped polycrystalline silicon layer and improves the bifacial coefficient of the battery by using silicon-containing protrusions that are taller and / or narrower in width, without destroying the tunnel passivation effect of the doped polycrystalline silicon layer, and improves the photoelectric conversion effect of the battery.

[0038] The black dots in Figure 3 and the white particles in Figure 6 represent silicon-containing protrusions. These silicon-containing protrusions have a partially spherical structure, such as a hemisphere. The height of the silicon-containing protrusions (approximately the radius of the silicon-containing protrusions) is between 150 nm and 450 nm, and may be, for example, 150 nm, 200 nm, 300 nm, 400 nm, or 450 nm, but is not limited to these values.

[0039] According to the embodiments of this application, a good light confinement effect can be achieved by setting the height of the silicon-containing protrusion particles to 150 nm to 450 nm. If the height of the silicon-containing protrusion particles is too small, for example, less than 150 nm, sunlight cannot be refracted multiple times by the silicon-containing protrusion particles and the uneven sidewalls, making it difficult to achieve a light confinement effect. If the silicon-containing protrusion particles are too large, it degrades the film deposition quality of the doped polycrystalline silicon, which is unfavorable for the photoelectric conversion efficiency of the battery.

[0040] According to the embodiment of this application, at least a portion of the surface of the doped polycrystalline silicon layer 3 of the solar cell, away from the tunnel oxide layer 2, has silicon-containing protruding particles. As shown in Figure 4B, there are two high protrusions on the surface of the doped polycrystalline silicon layer (regions indicated by arrows in Figure 4B), which correspond to the two silicon-containing protruding particles on the surface of the doped polycrystalline silicon layer in Figure 4A (two black dots indicated by arrows in Figure 4A). This indicates that the doped polycrystalline silicon layer has silicon-containing protruding particles on the surface away from the tunnel oxide layer. As shown in Figure 6, the white dots are silicon-containing protruding particles. The height of the silicon-containing protruding particles is greater than the height of the undulation structure, and the height of the silicon-containing protruding particles is close to the height of the pyramidal structure (the height of the pyramidal structure for light confinement is generally less than 1 μm). The incident sunlight is refracted multiple times by the silicon-containing protruding particles, allowing more sunlight to enter the semiconductor substrate 1, increasing the light confinement effect on at least one of the surfaces of the solar cell and further improving the bifacial coefficient of the solar cell.

[0041] According to the embodiments of this application, silicon-containing protruding particles are provided on the surface of the doped polycrystalline silicon layer 3 located near at least one corner or one side of the semiconductor substrate 1.

[0042] According to the embodiments of this application, the distance from the silicon-containing protruding particles to the edge of the semiconductor substrate 1 is less than 3 mm, and may be, for example, 1 mm, 2 mm, or 3 mm, but is not limited to the values ​​given.

[0043] As shown in Figure 2, the second surface of the semiconductor substrate 1 has a non-pyramidal texture structure, which includes multiple substructures (shown as rectangles in Figure 2), and the tunnel oxide layer 2 and the doped polycrystalline silicon layer 3 are deposited sequentially on the second surface of the semiconductor substrate 1. Multiple silicon-containing protrusions (shown as black dots in Figure 2) are formed on the surface of the doped polycrystalline silicon layer 3 adjacent to the edge of the semiconductor substrate 1.

[0044] The point to explain is that the refractive index of incident light changes due to the silicon-containing protrusions, and if there are too many silicon-containing protrusions in a large area, color unevenness in the battery cell can occur. Specifically, the silicon-containing protrusions increase the surface roughness of the doped polycrystalline silicon layer, causing differences in the reflection of light of different wavelengths by the doped polycrystalline silicon layer, resulting in color unevenness in the battery cell. Therefore, by controlling the silicon-containing protrusions to an appropriate range (silicon-containing protrusions within 3 mm from the edge of the semiconductor substrate 1), the light confinement effect on the battery surface can be increased, improving the bifacial coefficient of the battery, and avoiding problems such as the removal of battery cells during the manufacturing process due to color unevenness and appearance defects in the final battery product.

[0045] According to an embodiment of this application, as shown in Figure 1, the back-contact solar cell includes two non-electrode collection regions 4 located on the second surface of the semiconductor substrate 1 and an electrode collection region located between the two non-electrode collection regions 4. The electrode collection region includes a plurality of minority carrier regions 31 and a plurality of majority carrier regions 32 alternately distributed along a first direction, with an isolation region 33 between the minority carrier regions 31 and the majority carrier regions 32.

[0046] According to the embodiment of this application, the doped polycrystalline silicon layer 3 includes a first doped polycrystalline silicon layer 34 and a second doped polycrystalline silicon layer 35, where the first doped polycrystalline silicon layer 34 for collecting and extracting minority carriers is located in a minority carrier region 31, and the second doped polycrystalline silicon layer 35 for collecting and extracting majority carriers is located in a majority carrier region 32. Here, the conductivity types of the first doped polycrystalline silicon layer 34 and the second doped polycrystalline silicon layer 35 are opposite, with one of the first doped polycrystalline silicon layer 34 and the second doped polycrystalline silicon layer 35 being N-type and the other being P-type. For example, the conductivity type of the first doped polycrystalline silicon layer 34 may be N-type, in which case the conductivity type of the second doped polycrystalline silicon layer 35 is P-type. Alternatively, the conductivity type of the first doped polycrystalline silicon layer 34 may be P-type, in which case the conductivity type of the second doped polycrystalline silicon layer 35 is N-type.

[0047] According to the embodiments of this application, the semiconductor substrate 1 may be an N-type semiconductor substrate or a P-type semiconductor substrate. The conductivity type of the semiconductor substrate 1 is the same as that of the second doped polycrystalline silicon layer 35.

[0048] In the embodiments of this application, we will explain using the example that the semiconductor substrate 1 is N-type, the first doped polycrystalline silicon layer 34 is P-type, and the second doped semiconductor layer 35 is N-type.

[0049] According to the embodiments of this application, silicon-containing protruding particles are present on the surface of the first doped polycrystalline silicon layer 34 and / or the second doped polycrystalline silicon layer 35.

[0050] According to the embodiments of this application, the surface of the first doped polycrystalline silicon layer 34 has silicon-containing protruding particles.

[0051] According to the embodiments of this application, the second doped polycrystalline silicon layer 35 has silicon-containing protruding particles on its surface.

[0052] According to the embodiments of this application, the first doped polycrystalline silicon layer 34 and the second doped polycrystalline silicon layer 35 each have silicon-containing protruding particles on their surfaces.

[0053] In some embodiments, the N-type doped polycrystalline silicon layer has multiple protrusion structures on at least a portion of its surface away from the tunnel oxide layer. These protrusion structures increase the effective light absorption of the N-type doped polycrystalline silicon layer, improving the bifacial coefficient of the solar cell. They also increase the contact area between the N-type doped polycrystalline silicon layer and the metal electrode, contributing to a reduction in contact resistance. Furthermore, the P-type doped polycrystalline silicon layer lacks protrusion structures on its surface away from the tunnel oxide layer, resulting in a flatter surface and contributing to the realization of a more favorable tunnel passivation effect.

[0054] In some embodiments, the N-type doped polycrystalline silicon layer can be configured to have no protrusions on its surface, while the P-type doped polycrystalline silicon layer has multiple protrusions on at least a portion of its surface away from the tunnel oxide layer 2, in accordance with the actual performance requirements of the solar cell. In the N-type substrate, the P-type doped polycrystalline silicon layer is used as the emitter region and has multiple protrusions on its surface, thereby increasing the light absorption of the P-type region, exciting more carriers, improving the bifacial coefficient, and further reducing the contact resistance of the P-type region.

[0055] According to the embodiments of this application, at least two first doped polycrystalline silicon layers 34 have silicon-containing protruding particles on their surfaces.

[0056] According to the embodiments of this application, at least two second doped polycrystalline silicon layers 35 have silicon-containing protruding particles on their surfaces.

[0057] According to the embodiments of this application, silicon-containing protruding particles are present on the surface of the first doped polycrystalline silicon layer 34 and / or the second doped polycrystalline silicon layer 35, and incident light is refracted multiple times by the silicon-containing protruding particles, allowing even more light to enter the surface of the semiconductor substrate 1. Therefore, the more doped polycrystalline silicon layers with silicon-containing protruding particles there are, the greater the light confinement effect on the second surface of the battery and the higher the bifacial coefficient of the battery.

[0058] According to embodiments of this application, at least one surface of the semiconductor substrate 1 has a non-pyramidal texture structure, the non-pyramidal texture structure comprises a plurality of substructures, the doped polycrystalline silicon layer on the apex of the substructure has silicon-containing protruding particles, the distribution density of silicon-containing protruding particles in the N-type doped polycrystalline silicon layer located on the apex of the substructure is greater than the distribution density of silicon-containing protruding particles in the P-type doped polycrystalline silicon layer located on the apex of the substructure.

[0059] According to the embodiments of this application, in the manufacturing process of back-contact solar cells, the doping concentration of the N-type region-doped polycrystalline silicon layer is usually higher than that of the P-type region-doped polycrystalline silicon layer, leading to more severe Auger recombination in the N-type region. Therefore, by controlling the distribution density of silicon-containing protrusions in the N-type doped polycrystalline silicon layer to be greater than that of silicon-containing protrusions in the P-type doped polycrystalline silicon layer, the photoconfinement effect of the N-type region can be increased, compensating for the loss of Auger recombination in the N-type region and reducing the difference in photoconfinement effects between the N-type and P-type regions. This helps to improve the carrier collection quantity in the N-type region and further improves the photoelectric conversion efficiency of the back-contact solar cell.

[0060] According to the embodiments of the present application, at least one surface of the semiconductor substrate 1 has a non-pyramidal texture structure, the non-pyramidal texture structure includes a plurality of sub-structures, the doped polycrystalline silicon layer on the top surface of the sub-structure has silicon-containing protrusion particles, and the distribution density of the silicon-containing protrusion particles in the doped polycrystalline silicon layer on the top surface of at least one sub-structure is 0.1 to 0.5 particles / μm 2 That is. For example, 0.1 particles / μm 2 , 0.2 particles / μm 2 , 0.3 particles / μm 2 , 0.4 particles / μm 2 , 0.5 particles / μm 2 It may be, but is not limited to the values listed. The top surface refers to a complete polygonal or complete arc-shaped structure that can be observed in the top view of the battery product, and corresponds to the surface of the silicon substrate that is recessed into the silicon substrate.

[0061] According to the embodiments of the present application, at the same cross-sectional length, the number of distributed protrusion particles is smaller than the number of distributed undulating structures. For example, as shown in FIG. 5, at the same magnification and the same window length, the number of distributed undulating structures is larger than the number of distributed silicon-containing protrusion particles.

[0062] It should be noted that the silicon-containing protrusion particles may be distributed on any of the doped polycrystalline silicon layers on the bottom surface, top surface and side surface of the sub-structure of the non-pyramidal texture structure. For the convenience of characterization, the present application selects the top surface of the sub-structure to quantify the distribution density of the silicon-containing protrusion particles.

[0063] According to the embodiments of the present application, the back surface of the solar cell has an uneven structure and silicon-containing protrusion particles. Since the incident sunlight is refracted multiple times by the silicon-containing protrusion particles and the uneven side walls, more sunlight is incident on the surface of the semiconductor substrate. Therefore, the doped polycrystalline silicon layer with more densely distributed silicon-containing protrusion particles further increases the light confinement effect on the back surface of the battery and improves the bifaciality coefficient of the solar cell.

[0064] In some embodiments, the doped polycrystalline silicon layer 3 has multiple depression structures on at least a portion of the surface away from the tunnel oxide layer 2, thereby improving the light confinement effect of at least one of the solar cells and further improving the bifacial coefficient of the solar cell.

[0065] Here, the N-type doped polycrystalline silicon layer and / or the P-type doped polycrystalline silicon layer have multiple depression structures on at least a portion of their surfaces. That is, the N-type doped polycrystalline silicon layer has multiple depression structures on at least a portion of its surface away from the tunnel oxide layer 2, and the P-type doped polycrystalline silicon layer does not have depression structures on its surface away from the tunnel oxide layer 2. Or, the N-type doped polycrystalline silicon layer does not have depression structures on its surface away from the tunnel oxide layer 2, and the P-type doped polycrystalline silicon layer has depression structures on at least a portion of its surface away from the tunnel oxide layer 2. Or, the N-type doped polycrystalline silicon layer and the P-type doped polycrystalline silicon layer each have multiple depression structures on at least a portion of their surfaces away from the tunnel oxide layer 2, and the distribution density of the depression structures contained in them is different.

[0066] In some embodiments, the depth of the recess structure is 80 nm to 150 nm, and may be, for example, 80 nm, 100 nm, 120 nm, 130 nm, or 150 nm, but is not limited to the values ​​listed above.

[0067] In some embodiments, as shown in Figure 5, the surface of the doped polycrystalline silicon layer adjacent to the edge of the semiconductor substrate has a dot-like or linear depression structure, where the depth of the depression structure is less than the thickness of the doped polycrystalline silicon layer.

[0068] In some embodiments, the recessed structure has a length of 150 nm to 630 nm in the direction parallel to the surface of the semiconductor substrate 1, and may be, for example, 150 nm, 200 nm, 300 nm, 500 nm, or 630 nm, but is not limited to the values ​​listed above.

[0069] According to the embodiments of this application, the depth of the recessed structure is greater than the height of the undulating structure, that is, the degree of undulation of the recessed structure is greater than that of the undulating structure, and the recessed structure is closer to the height of the pyramid (the height of the pyramidal structure for light confinement is generally less than 1 μm), further improving the light confinement effect and improving the bifacial coefficient.

[0070] In some embodiments, the N-type doped polycrystalline silicon layer has multiple depression structures on at least a portion of its surface away from the tunnel oxide layer 2, where the depth of the depression structures is greater than the height of the relief structures. In other embodiments, the P-type doped polycrystalline silicon layer does not have depression structures on its surface away from the tunnel oxide layer 2.

[0071] In the embodiments of this application, the surface of the N-type doped polycrystalline silicon layer away from the tunnel oxide layer has a plurality of depression structures. These depression structures increase the effective light absorption of the N-type doped polycrystalline silicon layer, improving the bifacial coefficient of the solar cell. They also increase the contact area between the N-type doped polycrystalline silicon layer and the metal electrode, contributing to a reduction in contact resistance. Furthermore, the surface of the P-type doped polycrystalline silicon layer away from the tunnel oxide layer lacks depression structures, resulting in a flatter surface and contributing to the realization of a more favorable tunnel passivation effect.

[0072] For the sake of characterization, this application selects the apex of the substructure of the non-pyramidal texture structure and quantifies the distribution density of the depression structure.

[0073] In some examples, the distribution density of depressions on the top surface of the substructure was 50,000 / mm². 2 ~300000 pieces / mm 2Therefore, the distribution density of the recess structure in the N-type doped polycrystalline silicon layer or the recess structure in the P-type doped polycrystalline silicon layer can be selected from the above ranges. It should be explained that if the distribution density of the recess structure is too high, it reduces the tunnel passivation effect of the passivation contact structure (the passivation contact structure includes a tunnel oxide layer and a doped polycrystalline silicon layer), and if the distribution density of the recess structure is too low, a sufficient light confinement effect cannot be achieved. In this application, a recess structure having a specific distribution density achieves a light confinement effect without significantly reducing the tunnel passivation effect of the passivation contact structure.

[0074] In some embodiments, to meet the actual performance requirements of the solar cell, the N-type doped polycrystalline silicon layer can be configured to have no depressions on its surface, while the P-type doped polycrystalline silicon layer has multiple depressions on at least a portion of its surface away from the tunnel oxide layer 2, where the depth of the depressions in the P-type doped polycrystalline silicon layer is greater than the height of the undulations.

[0075] According to the embodiments of this application, in the N-type substrate, P-type doped polycrystalline silicon is used as the emitter region, and the surface thereof has multiple depression structures, thereby increasing the light absorption of the P-type region, exciting more carriers, improving the bifacial coefficient, and further reducing the contact resistance of the P-type region.

[0076] In some embodiments, the N-type doped polycrystalline silicon layer has a plurality of depression structures on at least a portion of its surface away from the tunnel oxide layer 2, and the P-type doped polycrystalline silicon layer also has a plurality of depression structures on at least a portion of its surface away from the tunnel oxide layer 2. In other words, the surface of the N-type doped polycrystalline silicon layer on the top surface of at least some of the substructures has a plurality of depression structures, and the surface of the P-type doped polycrystalline silicon layer on the top surface of at least some of the substructures has a plurality of depression structures, where the distribution density of the depression structures in the N-type doped polycrystalline silicon layer on the top surface of the substructure is greater than the distribution density of the depression structures in the P-type doped polycrystalline silicon layer on the top surface of the substructure.

[0077] In the embodiments of this application, the doping concentration of the N-type region-doped polycrystalline silicon layer is usually higher than that of the P-type region-doped polycrystalline silicon layer, leading to more severe Auger recombination in the N-type region. Therefore, by controlling the distribution density of depression structures in the N-type region-doped polycrystalline silicon layer to be greater than that of depression structures located in the P-type region-doped polycrystalline silicon layer, the photoconfinement effect of the N-type region can be increased, compensating for the loss of Auger recombination in the N-type region and reducing the difference in photoconfinement effects between the N-type and P-type regions. This helps to improve the amount of carriers collected in the N-type region and further improves the photoelectric conversion efficiency of the back-contact solar cell.

[0078] In some embodiments, the solar cell further includes a passivation anti-reflective layer located on the surface of the doped polycrystalline silicon layer 3 away from the semiconductor substrate 1, wherein the height of the silicon-containing protrusions is greater than the thickness of the passivation anti-reflective layer, and / or the height of the silicon-containing protrusions is less than three times the thickness of the passivation anti-reflective layer.

[0079] According to the embodiments of this application, after depositing a passivation anti-reflective layer on a doped polycrystalline silicon layer 3, silicon-containing protruding particles are present on at least a portion of the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2. Therefore, protruding particles are also formed on at least a portion of the surface of the deposited passivation anti-reflective layer.

[0080] According to the embodiments of this application, the silicon-containing protruding particles have a certain height, increasing the contact area with the passivation anti-reflective layer, further increasing the area of ​​the passivation anti-reflective layer, and improving light absorption. Furthermore, the height of the protruding particles should be less than three times the thickness of the passivation anti-reflective layer, and the protruding particles should not be too tall. If they are too tall, it will affect the uniformity of the passivation anti-reflective layer and reduce the passivation effect.

[0081] According to embodiments of this application, the passivation anti-reflective layer comprises a laminate of aluminum oxide and one or more of silicon nitride, silicon oxide, or silicon oxynitride, and the thickness of the passivation anti-reflective layer refers to the total thickness of the laminate.

[0082] For example, the thickness of the aluminum oxide / silicon nitride layer is 100 nm, where the thickness of the aluminum oxide is 5 nm and the thickness of the silicon nitride is 95 nm. The particle size of the protrusions is approximately 300-400 nm, and the height of the protrusions is 150-200 nm.

[0083] According to the embodiments of this application, by depositing a passivation anti-reflective layer on a doped polycrystalline silicon layer, the passivation layer is filled into the recessed structure of the doped polycrystalline silicon layer, and the surface of the passivation layer also has a recessed structure. This increases the surface area of ​​the passivation layer and further improves the passivation effect of the passivation layer. For example, a passivation anti-reflective layer such as an aluminum oxide / silicon nitride laminate is filled into the recessed structure of the doped polycrystalline silicon layer.

[0084] According to the embodiments of this application, the silicon-containing protruding particles contain at least one of the elements C, N, and O.

[0085] According to the embodiments of this application, the silicon-containing protruding particles in the doped polycrystalline silicon layer have C and / or N elements, which can improve the flexibility of the solar cell.

[0086] According to the embodiments of this application, the silicon-containing protruding particles in the doped polycrystalline silicon layer have element O, which can improve the conductivity of the doped polycrystalline silicon layer and further reduce the contact resistance.

[0087] According to the embodiments of this application, the silicon-containing protruding particles contain elements of Group 3 and / or Group 5, wherein the content of Group 3 and / or Group 5 elements in the silicon-containing protruding particles is greater than the content of Group 3 and / or Group 5 elements in the corresponding tunnel oxide layer located in the same doped region, and the content of Group 3 and / or Group 5 elements in the corresponding tunnel oxide layer in the same doped region is greater than the content of Group 3 and / or Group 5 elements in the corresponding semiconductor substrate in the same doped region, thereby further reducing contact resistance, forming tunnel passivation characteristics in the doped polycrystalline silicon layer and the tunnel oxide layer, and reducing the recombination of photogenerated carriers in the semiconductor substrate.

[0088] According to the embodiments of this application, the content of doped elements O, N, C, Group 3 elements, and / or Group 5 elements is lower than the content of silicon. By controlling the doped elements to be lower than the content of silicon, it is possible to avoid the recombination of photogenerated carriers due to defects caused by excessive doping of the elements, thereby reducing the minority carrier lifetime.

[0089] According to the embodiments of this application, the silicon-containing protruding particles include, for example, Si, N, C, O, and P elements, where the Si content is 53.11 at.%, the C content is 17.93 at.%, the N content is 22.26 at.%, the O content is 6.3 at.%, and the P content is 0.4 at.%.

[0090] According to the embodiments of this application, by incorporating elements C, O, and IIIA / VA into silicon-containing protruding particles, the phototrapping effect of the silicon-containing protruding particles can be increased, while the contact resistance can be reduced, thereby improving the photoelectric conversion efficiency of the solar cell.

[0091] According to the embodiments of this application, the front and back isolation regions 33 of the back-contact solar cell have a pyramidal structure. The height of the silicon-containing protruding particles is smaller than the height of the pyramidal structure in the back isolation region 33 of the back-contact solar cell, and is also smaller than the height of the pyramidal structure on the front of the back-contact solar cell.

[0092] According to the embodiments of this application, the silicon-containing protruding particles have a rough surface, which further increases the photoconfinement effect on the surface of the doped polycrystalline silicon layer having the silicon-containing protruding particles, thereby improving the bifacial coefficient of the battery.

[0093] According to the embodiment of this application, the solar cell further includes a first electrode 10 located on a surface of the first doped polycrystalline silicon layer 34 away from the semiconductor substrate 1, and a second electrode 20 located on a surface of the second doped polycrystalline silicon layer 35 away from the semiconductor substrate 1.

[0094] According to the embodiments of this application, silicon-containing protrusions are formed on at least a portion of the surface of the doped polycrystalline silicon layer of the BC solar cell while maintaining the original surface irregularities and the geometric size of the grid lines. During the light incidence process, the incident light is refracted multiple times between the silicon-containing protrusions and the irregularities, allowing more incident light to reach the semiconductor substrate. This increases the light confinement effect on the back surface of the BC solar cell and further improves the bifacial coefficient of the BC solar cell. By maintaining the characteristics of the original irregularities and grid lines, the passivation and contact effects of the cell can be maintained, and in combination with the silicon-containing protrusions on the surface of the doped polycrystalline silicon layer, good passivation, contact, and light confinement effects of the BC solar cell can be simultaneously achieved.

[0095] As shown in Figure 7, according to the embodiment of this application, the solar cell may be a double-sided contact solar cell, for example, a TOPCon solar cell.

[0096] According to embodiments of this application, a tunnel oxide passivation contact structure consisting of a tunnel oxide layer 2 and a doped polycrystalline silicon layer 3 can be formed on at least one surface of a semiconductor substrate 1. For example, the tunnel oxide passivation contact structure can be formed on one or two surfaces of the semiconductor substrate 1, or it can be formed in a local region on at least one surface of the semiconductor substrate 1. In other words, this application can also be applied to local TOPCon solar cells, TBC solar cells, or BC batteries having a TOPCon structure in one region, as long as the TOPCon structure is included.

[0097] According to the embodiment of this application, as shown in Figure 7, the semiconductor substrate 1 has opposite first and second surfaces, and the tunnel oxide passivation contact structure, consisting of a tunnel oxide layer 2 and a doped polycrystalline silicon layer 3, is formed on the second surface of the semiconductor substrate 1.

[0098] According to the embodiment of this application, the TOPCon solar cell further includes an emitter 5 and a first passivation layer 6 located on the first surface of the semiconductor substrate 1, and a second passivation layer 7 located on the second surface of the semiconductor substrate 1. Here, the first passivation layer 6 and the second passivation layer 7 realize a passivation reflection prevention function.

[0099] According to the embodiments of this application, the TOPCon solar cell further includes a third electrode 30 located on the first surface of the semiconductor substrate 1 and a fourth electrode 40 located on the second surface of the semiconductor substrate 1.

[0100] The electrodes and passivation layer of the solar cell are cleaned and removed to expose the doped polycrystalline silicon layer beneath the electrodes. As shown in Figure 8, the surface of the exposed doped polycrystalline silicon layer has silicon-containing protruding particles (indicated by white dots in Figure 8).

[0101] As shown in Figures 8 and 9A to 9B, the electrodes and passivation layer of the solar cell were cleaned and removed, and it was observed that silicon-containing protruding particles remained on the surface of the doped polycrystalline silicon layer beneath the electrodes. An EDS test was performed on an arbitrary location in the doped polycrystalline silicon layer, and the EDS test results indicated that the silicon-containing protruding particles were composed of silicon.

[0102] According to one exemplary embodiment of this application, the application provides a method for manufacturing a solar cell, comprising operations S01 to S03.

[0103] In operation S01, the semiconductor substrate 1 is polished to obtain a semiconductor substrate 1 having an uneven surface on both the first and second surfaces.

[0104] According to the embodiment of this application, an initial silicon wafer cut with a diamond wire is polished to obtain a semiconductor substrate 1 having an uneven structure on both the first and second surfaces.

[0105] According to the embodiments of this application, the width of the uneven structure is 5 μm to 50 μm, and may be, for example, 5 μm, 10 μm, 20 μm, 40 μm, or 50 μm, but is not limited to the values ​​listed. The difference in height between adjacent uneven surfaces is 0.2 μm to 8 μm, and may be, for example, 0.2 μm, 1 μm, 2 μm, 4 μm, 5 μm, 6 μm, or 8 μm, but is not limited to the values ​​listed.

[0106] In operation S02, a tunnel oxide layer 2 is deposited on at least one surface of the semiconductor substrate 1.

[0107] According to the embodiments of this application, the tunnel oxide layer 2 is SiO2 with a thickness of 1 to 5 nm.

[0108] In operation S03, a doped polycrystalline silicon layer 3 is deposited on the surface of the tunnel oxide layer 2 away from the semiconductor substrate 1, and at least a portion of the surface of the doped polycrystalline silicon layer 3 away from the tunnel oxide layer 2 has silicon-containing protruding particles.

[0109] According to the embodiment of this application, a doped polycrystalline silicon layer 3 is deposited using the Low Pressure Chemical Vapor Deposition (LPCVD) method. Specifically, after depositing a tunnel oxide layer 2, a semiconductor substrate 1 having an uneven surface structure is sent into a tubular furnace to deposit a thin film, and a doped polycrystalline silicon layer 3 having silicon-containing protruding particles on its surface is obtained under conditions of high source volume, high temperature, and high pressure.

[0110] According to the embodiments of this application, the silane flow rate is 100 sccm to 1000 sccm, and may be, for example, 100 sccm, 200 sccm, 500 sccm, 800 sccm, or 1000 sccm, but is not limited to the values ​​listed.

[0111] According to the embodiments of this application, the deposition temperature for high-temperature thin film deposition is 500°C to 700°C, and may be, for example, 500°C, 550°C, 600°C, 650°C, or 700°C, but is not limited to the values ​​listed.

[0112] According to the embodiments of this application, the high-pressure thin film deposition pressure is 50 to 400 mTorr, and may be, for example, 50 mTorr, 100 mTorr, 200 mTorr, 300 mTorr, or 400 mTorr, but is not limited to the values ​​listed above.

[0113] According to the embodiments of this application, when the amount of silane is sufficient, the deposition temperature is high, and the deposition pressure is high in the thin film deposition process, the deposition rate is high, so the silane cannot instantaneously complete the decomposition and reaction, reducing the continuity and uniformity of thin film deposition and growth, and silicon-containing particles are present in the doped polycrystalline silicon layer after deposition.

[0114] According to the embodiments of this application, in the process of depositing a doped polycrystalline silicon layer, the deposition temperature and silane gas flow rate are increased in the doped polycrystalline silicon layer near the edge of the semiconductor substrate, thereby providing silicon-containing protruding particles on the surface of the doped polycrystalline silicon layer located near one corner or one side of the semiconductor substrate.

[0115] According to one exemplary embodiment of this application, this application provides a solar module including the above-mentioned solar cell.

[0116] According to the embodiments of this application, silicon-containing protruding particles are formed on at least a portion of the surface of the doped polycrystalline silicon layer, away from the tunnel oxide layer, thereby improving the surface light confinement effect of the solar cell. By forming a solar module with this solar cell that improves the surface light confinement effect, the bifacial coefficient of the solar module is improved.

[0117] According to embodiments of this application, at least a portion of the surface of the doped polycrystalline silicon layer in a solar module opposite to the tunnel oxide layer has silicon-containing protruding particles.

[0118] According to embodiments of this application, at least a portion of the surface of the doped polycrystalline silicon layer in the solar module opposite to the tunnel oxide layer has silicon-containing protruding particles.

[0119] According to the embodiment of this application, the solar module includes a ribbon for electrically connecting two adjacent solar cells, and on the second surface of the semiconductor substrate 1, there is a gap between the ribbon and a doped polycrystalline silicon layer 3 having silicon-containing protruding particles.

[0120] According to the embodiments of this application, the ribbon may be parallel or perpendicular to the direction of extension of the doped polycrystalline silicon layer, and the ribbon does not obstruct the doped polycrystalline silicon layer having silicon-containing protruding particles, and does not affect the improvement of the bifacial coefficient of the solar cell.

[0121] The ordinal terms such as "first," "second," and "third" used in the specification and claims modify the corresponding elements and do not in themselves imply that the elements have any ordinal number, nor do they indicate the order of one element to another or the order of a manufacturing method. These ordinal numbers are used simply to clearly distinguish one element having a certain name from another element having the same name.

[0122] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this application. It should be understood that the above are merely specific embodiments of this application and are not intended to limit it. Any modifications, equivalent substitutions, improvements, etc., made insofar as they do not deviate from the spirit and principles of this application will all be included within the scope of protection of this application. [Explanation of Symbols]

[0123] 1. Semiconductor substrate 2. Tunnel oxide layer 3. Doped polycrystalline silicon layer 31. Minority Career Areas 32 Multiple Career Areas 33 Quarantine area 34. First doped polycrystalline silicon layer 35. Second doped polycrystalline silicon layer 4. Non-electrode collection area 10 1st electrode 20 2nd electrode 5 Emitter 6. First Passivation Layer 7. Second Passivation Layer 30 3rd electrode 40 4th electrode

Claims

1. It is a solar cell, Semiconductor substrate (1), A tunnel oxide layer (2) located on at least one surface of the semiconductor substrate (1), The tunnel oxide layer (2) includes a doped polycrystalline silicon layer (3) located on a surface of the tunnel oxide layer (2) away from the semiconductor substrate (1), At least a portion of the surface of the doped polycrystalline silicon layer (3) that is away from the tunnel oxide layer (2) has silicon-containing protruding particles. The solar cell further includes a passivation anti-reflective layer located on the surface of the doped polycrystalline silicon layer (3) away from the semiconductor substrate (1), The height of the silicon-containing protruding particles is greater than the thickness of the passivation anti-reflective layer, and the height of the silicon-containing protruding particles is less than three times the thickness of the passivation anti-reflective layer. A solar cell characterized in that the solar cell is a back-contact solar cell, the front surface of the back-contact solar cell includes a pyramidal structure, the front surface is positioned opposite to at least one of the surfaces, and the height of the silicon-containing protruding particles is smaller than the height of the pyramidal structure on the front surface of the solar cell.

2. The solar cell according to claim 1, characterized in that the surface of the doped polycrystalline silicon layer (3) located at least in close proximity to one corner or one side of the semiconductor substrate (1) has silicon-containing protruding particles, and the aforementioned close proximity is within 3 mm or less from the edge of the semiconductor substrate 1.

3. The surface of the doped polycrystalline silicon layer (3) away from the tunnel oxide layer (2) further has a plurality of undulating structures, The solar cell according to claim 1, characterized in that the height of the silicon-containing protruding particles is greater than the height of the undulating structure.

4. The doped polycrystalline silicon layer (3) includes a plurality of first doped polycrystalline silicon layers (34) and a plurality of second doped polycrystalline silicon layers (35) distributed alternately at intervals in a first direction, wherein one of the first doped polycrystalline silicon layer (34) and the second doped polycrystalline silicon layer (35) is N-type, and the other of the first doped polycrystalline silicon layer (34) and the second doped polycrystalline silicon layer (35) is P-type. The first doped polycrystalline silicon layer (34) and / or the second doped polycrystalline silicon layer The solar cell according to claim 1, characterized in that the surface of (35) has silicon-containing protruding particles.

5. The semiconductor substrate (1) has at least one surface having a non-pyramidal texture structure, the non-pyramidal texture structure includes a plurality of substructures, and the doped polycrystalline silicon layer on the top surface of the substructure has silicon-containing protruding particles. The solar cell according to claim 4, characterized in that the distribution density of silicon-containing protrusion particles in the N-type doped polycrystalline silicon layer located on the apex of the substructure is greater than the distribution density of silicon-containing protrusion particles in the P-type doped polycrystalline silicon layer located on the apex of the substructure, the non-pyramidal texture structure is an uneven structure, and the substructure is one of the uneven structures.

6. The semiconductor substrate (1) has at least one surface having a non-pyramidal texture structure, the non-pyramidal texture structure includes a plurality of substructures, and the doped polycrystalline silicon layer on the top surface of the substructure has silicon-containing protruding particles. The distribution density of silicon-containing protrusion particles in the doped polycrystalline silicon layer on the top surface of at least one of the substructures is 0.1 to 0.5 particles / μm ２ The solar cell according to claim 1, wherein the non-pyramidal texture structure is an uneven structure, and the substructure is one of the uneven structures.

7. The solar cell according to claim 3, characterized in that, for the same cross-sectional length, the number of distributed protruding particles is smaller than the number of distributed undulating structures.

8. The doped polycrystalline silicon layer (3) includes a plurality of first doped polycrystalline silicon layers and a plurality of second doped polycrystalline silicon layers distributed alternately at intervals in a first direction, wherein one of the first doped polycrystalline silicon layers and the second doped polycrystalline silicon layer is N-type, and the other of the first doped polycrystalline silicon layer and the second doped polycrystalline silicon layer is P-type. The solar cell according to claim 1, characterized in that at least a portion of the surface of the N-type doped polycrystalline silicon layer away from the tunnel oxide layer (2) has a plurality of recessed structures, and / or at least a portion of the surface of the P-type doped polycrystalline silicon layer away from the tunnel oxide layer (2) has a plurality of recessed structures.

9. The semiconductor substrate (1) has at least one surface having a non-pyramidal texture structure, the non-pyramidal texture structure includes a plurality of substructures, and the doped polycrystalline silicon layer on the top surface of the substructure has a plurality of depression structures. The distribution density of the depressions located on the apex of the aforementioned substructure is 50,000 per mm². ２ ~300000 pieces / mm ２ The solar cell according to claim 8, wherein the non-pyramidal texture structure is an uneven structure, and the substructure is one of the uneven structures.

10. The semiconductor substrate (1) has at least one surface which has a non-pyramidal texture structure which includes a plurality of substructures. At least some of the substructures have a plurality of depression structures on the surface of the N-type doped polycrystalline silicon layer away from the tunnel oxide layer (2) on the top surface of the substructure, and at least some of the substructures have a plurality of depression structures on the surface of the P-type doped polycrystalline silicon layer away from the tunnel oxide layer (2) on the top surface of the substructure, The solar cell according to claim 8, characterized in that the distribution density of the depression structure of the N-type doped polycrystalline silicon layer located on the apex of the substructure is greater than the distribution density of the depression structure of the P-type doped polycrystalline silicon layer located on the apex of the substructure, the non-pyramidal texture structure is an uneven structure, and the substructure is one of the uneven structures.

11. The doped polycrystalline silicon layer (3) further includes a passivation anti-reflective layer located on the surface away from the semiconductor substrate (1), The solar cell according to claim 8, characterized in that the passivation anti-reflective layer is filled in the recessed structure.

12. The solar cell according to claim 1, characterized in that the silicon-containing protruding particles contain at least one of C, N, and O elements.

13. The solar cell according to claim 1, characterized in that the silicon-containing protruding particles contain elements of Group 3 and / or Group 5.

14. The height of the silicon-containing protruding particles is in the range of 150 nm to 450 nm. The aforementioned undulation structure has a length of 70 nm to 500 nm in the direction parallel to the surface of the semiconductor substrate (1). The solar cell according to claim 3, characterized in that the height of the undulating structure is 5 nm to 60 nm.

15. A solar module characterized by including a solar cell according to any one of claims 1 to 14.

16. Includes a ribbon for electrically connecting two adjacent solar cells. The solar module according to claim 15, characterized in that there is a gap between the ribbon and the doped polycrystalline silicon layer (3) having silicon-containing protruding particles in the planar direction of at least one surface of the semiconductor substrate (1).

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