Solar cell and its manufacturing method, photovoltaic module

Abstract

To provide, in the field of photovoltaics, a solar cell, a method for preparing the same, and a photovoltaic module.SOLUTION: A solar cell includes a substrate, a first dielectric layer located in an electrode region, and a first doped conductive layer located on the side of the first dielectric layer away from the electrode region. The substrate has first and second surfaces opposite to each other. The first surface includes: electrode regions and non-electrode regions alternately disposed with intervals; and transition regions located between the electrode regions and the non-electrode regions. The transition regions include a first surface structure, and the first surface structure includes multiple prismatic structures that are inclined toward the electrode regions. The prismatic structures are sequentially arranged at least along a first direction, and the first direction is the extension direction of the transition regions. An embodiment of the present disclosure is advantageous at least in improving the photoelectric conversion efficiency of the solar cell.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of photovoltaic power, and in particular, to solar cells and their manufacturing methods, and photovoltaic modules.

Background Art

[0002] Currently, solar cells are being used more and more widely as a new energy alternative. Solar cells utilize the principle of photovoltaic power generation to generate carriers and contribute to the effective utilization of electrical energy by extracting the carriers at the electrodes.

[0003] Currently, solar cells mainly include IBC (Interdigitated Back Contact) cells, TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated Emitter and Real Cell), and HJT (Heterojunction with Intrinsic Thinfilm) cells, etc.

[0004] However, currently, the photoelectric conversion efficiency of the designed solar cells needs to be further improved.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Embodiments of the present disclosure provide a solar cell and its manufacturing method, and a photovoltaic module that are at least advantageous for improving the photoelectric conversion efficiency of the solar cell.

Means for Solving the Problems

[0006] According to some embodiments of the present disclosure, in one embodiment of the embodiments of the present disclosure, a solar cell is provided which includes a substrate, a first dielectric layer located in an electrode region, and a first doping conductive layer located on the side of the first dielectric layer away from the electrode region, wherein the substrate has a first surface and a second surface which are opposite to each other, and the first surface includes an alternately spaced electrode region and a non-electrode region, and a transition region located between the electrode region and the non-electrode region, wherein the transition region comprises a first surface structure, and the first surface structure comprises a plurality of prismatic structures which are inclined toward the electrode region, and the plurality of prismatic structures are sequentially arranged along at least a first direction, the first direction being the direction in which the transition region extends.

[0007] In some embodiments, the prism structure includes a first prism structure and a second prism structure, wherein, along the inclination direction of the prism structure, the first length of the first prism structure is greater than the second length of the second prism structure, and at least a portion of the second prism structure is located on the side of the first prism structure away from the electrode region.

[0008] In some embodiments, multiple second prism structures are located on the side of the same first prism structure away from the electrode region, or multiple second prism structures are arranged sequentially along a direction away from the side of the first prism structure.

[0009] In some embodiments, the first surface structure further includes a first pyramidal structure, wherein at least some of the first pyramidal structures are located in a portion of the transition region that is close to the non-electrode region, and at least some of the prismatic structures are located in a portion of the transition region that is close to the electrode region.

[0010] In some embodiments, the first surface structure further comprises a plurality of micro-protrusion structures, the micro-protrusion structures comprising at least one of a second pyramidal structure or a triangular plate-like structure, wherein the one-dimensional dimension of the base of the micro-protrusion structure is smaller than the one-dimensional dimension of the base of the first pyramidal structure.

[0011] In some embodiments, the solar cell further includes a second dielectric layer covering the second surface and a second doping conductive layer covering the surface of the second dielectric layer away from the substrate, wherein the type of doping element in the first doping conductive layer is different from the type of doping element in the second doping conductive layer.

[0012] In some embodiments, the surface of the first doping conductive layer located in the electrode region comprises a second surface structure, the second surface structure comprising a plurality of third pyramidal structures, and the non-electrode region comprises a third surface structure, the third surface structure comprising a plurality of fourth pyramidal structures.

[0013] In some embodiments, the one-dimensional dimension of the base of the first pyramid structure is greater than the one-dimensional dimension of the base of the third pyramid structure, and the one-dimensional dimension of the base of the third pyramid structure is greater than the one-dimensional dimension of the base of the fourth pyramid structure.

[0014] In some embodiments, the solar cell further includes an intrinsic semiconductor layer covering the second surface, a second doping conductive layer covering the surface of the intrinsic semiconductor layer away from the substrate, and a transparent conductive layer covering the surface of the second doping conductive layer away from the intrinsic semiconductor layer, wherein the type of doping element in the first doping conductive layer is different from the type of doping element in the second doping conductive layer.

[0015] In some embodiments, the electrode region is either a positive electrode region or a negative electrode region, the first dielectric layer includes a first sub-dielectric layer located in the positive electrode region and a second sub-dielectric layer located in the negative electrode region, the first doping conductive layer includes a first sub-doping conductive layer located on the side of the first sub-dielectric layer closer to the positive electrode region and a second sub-doping conductive layer located on the side of the second sub-dielectric layer closer to the negative electrode region, and the type of doping element in the first sub-doping conductive layer is different from the type of doping element in the second sub-doping conductive layer.

[0016] In some embodiments, the electrode region comprises a fourth surface structure, the fourth surface structure comprising a plurality of platform ridge structures, the non-electrode region comprises a fifth surface structure, the fifth surface structure comprising a plurality of fifth pyramidal structures, wherein the one-dimensional dimension of the base of the first pyramidal structure is greater than the one-dimensional dimension of the base of the fifth pyramidal structure.

[0017] In some embodiments, the electrode region has a first upper surface, and the non-electrode region has a second upper surface, with respect to the second surface, the first upper surface is higher than the second upper surface, and the height difference between the first upper surface and the second upper surface is 0.5 μm to 10 μm.

[0018] According to some embodiments of the present disclosure, in one embodiment of the embodiments of the present disclosure, a method for manufacturing a solar cell is provided, the method for manufacturing a solar cell comprising providing an initial substrate, the initial substrate comprising an initial first surface and an initial second surface facing each other, the initial first surface comprising an initial electrode region and an initial non-electrode region alternately arranged at intervals, and an initial transition region located between the initial electrode region and the initial non-electrode region, forming an initial first dielectric layer covering the initial first surface, forming an initial first doping conductive layer covering the surface of the initial first dielectric layer away from the initial substrate, and the initial first dielectric layer located in the initial transition region and the initial non-electrode region in a laser process The electrolytic layer and the initial first doping conductive layer are removed to form a substrate having a first surface, wherein the initial electrode region, the initial transition region and the initial non-electrode region after processing by the laser process are, respectively, an electrode region, a transition region and a non-electrode region, the transition region comprises a first surface structure, the first surface structure includes a plurality of prismatic structures inclined toward the electrode region, the plurality of prismatic structures are sequentially arranged along at least a first direction, the first direction being the direction of extension of the transition region, the remaining initial first dielectric layer located in the electrode region is a first dielectric layer, and the remaining initial first doping conductive layer located in the electrode region is a first doping conductive layer.

[0019] In some embodiments, the step of forming the initial first dielectric layer further includes forming a second dielectric layer covering the initial second surface, and the step of forming the initial first doping conductive layer further includes forming a second doping conductive layer covering the surface of the second dielectric layer away from the initial substrate, wherein the type of doping element in the initial first doping conductive layer is different from the type of doping element in the second doping conductive layer.

[0020] In some embodiments, the process includes forming an intrinsic semiconductor layer covering the initial second surface before forming the initial first doping conductive layer, and in the step of forming the initial first doping conductive layer, the process includes forming a second doping conductive layer covering the surface of the intrinsic semiconductor layer away from the initial substrate, wherein the type of doping element in the initial first doping conductive layer is different from the type of doping element in the second doping conductive layer.

[0021] In some embodiments, the process further includes performing a first etching step on the initial first surface before forming the initial first dielectric layer to give the initial first surface a first texture structure, wherein the laser process removes the initial first dielectric layer and the initial first doping conductive layer located in the initial transition region and the initial non-electrode region, wherein the first doping conductive layer located in the initial electrode region comprises a second surface structure, the first texture structure located in the initial transition region is converted into the first surface structure, and the first texture structure located in the initial non-electrode region is converted into a third surface structure, where the second surface structure comprises a plurality of third pyramidal structures, the third surface structure comprises a plurality of fourth pyramidal structures, the one-dimensional dimension of the base of the first pyramidal structure is greater than the one-dimensional dimension of the base of the third pyramidal structure, and the one-dimensional dimension of the base of the third pyramidal structure is greater than the one-dimensional dimension of the base of the fourth pyramidal structure.

[0022] In some embodiments, the initial electrode region includes an initial positive electrode region and an initial negative electrode region, the formed first dielectric layer includes a first sub-dielectric layer and a second sub-dielectric layer, the first sub-dielectric layer is located in the positive electrode region and the second sub-dielectric layer is located in the negative electrode region, the formed first doping conductive layer includes a first sub-doping conductive layer and a second sub-doping conductive layer, the first sub-doping conductive layer is located on the side of the first sub-dielectric layer closer to the positive electrode region and the second sub-doping conductive layer is located on the side of the second sub-dielectric layer closer to the negative electrode region, and the type of doping element in the first sub-doping conductive layer is different from the type of doping element in the second sub-doping conductive layer.

[0023] According to some embodiments of the present disclosure, in one embodiment of the embodiments of the present disclosure, a photovoltaic module is provided, which includes a cell string made by connecting a plurality of the above-described solar cells or a plurality of solar cells formed by the above-described manufacturing method, a sealing adhesive film for covering the surface of the cell string, and a cover plate for covering the surface of the sealing adhesive film away from the cell string. [Effects of the Invention]

[0024] The technical solutions provided in the embodiments of this disclosure have at least the following advantages:

[0025] The first surface includes an electrode region, a transition region, and a non-electrode region. A stacked first dielectric layer and a first doped conductive layer are disposed in the electrode region, and the first dielectric layer and the first doped conductive layer constitute a passivation contact structure for the electrode region. Thus, the chemical passivation effect of the first dielectric layer on the electrode region and the field passivation effect of the first doped conductive layer on the electrode region improve the serious carrier recombination problem in the electrode region, and contribute to increasing the collection efficiency of carriers in the substrate of the electrode formed in the electrode region later. On the other hand, by forming the first dielectric layer and the first doped conductive layer only in the electrode region, it is possible to prevent the first dielectric layer and the first doped conductive layer from reducing the absorption of the non-electrode region and the transition region with respect to the incident light irradiated on the first surface 110. That is, while improving the serious carrier recombination problem in the electrode region, it contributes to ensuring a high absorption rate of the first surface with respect to incident light.

[0026] Furthermore, the transition region includes a plurality of prismatic structures inclined toward the electrode region, and the plurality of prismatic structures are sequentially arranged at least along the first direction, and the first direction is the extending direction of the transition region. That is, along the extending direction of the transition region, at least one row of prismatic structures is separated between the electrode region and the non-electrode region. By inclining this at least one row of prismatic structures toward the electrode region, the probability that the incident light incident on the transition region at different angles is absorbed by the transition region through the prismatic structures by at least one reflection becomes high, and the probability that the incident light is reflected by the prismatic structures by at least one reflection and absorbed by the non-electrode region becomes high, contributing to increasing the absorption rate of the first surface with respect to incident light.

[0027] Therefore, by improving the serious carrier recombination problem in the electrode region and increasing the absorption rate of the first surface with respect to incident light, the photoelectric conversion efficiency of the solar cell is improved.

Brief Description of the Drawings

[0028] One or more embodiments are illustrated by the figures in the corresponding accompanying drawings, but these illustrative descriptions are not limiting to the embodiments, and parts indicated by the same reference numerals in the accompanying drawings are similar parts, and unless otherwise specified, the figures in the accompanying drawings are not limited to scale. To more clearly illustrate the embodiments of this disclosure or the technical concepts in the prior art, the following drawings that may be used in the embodiments are briefly introduced below, but obviously the drawings described below represent only some embodiments of this disclosure, and those skilled in the art can derive other drawings based on these drawings without any creative work. [Figure 1] Figure 1 shows the local cross-sectional structure of a solar cell provided in one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic diagram of a local stereoelectron microscope image of a solar cell provided in one embodiment of the present disclosure. [Figure 3] Figure 3 shows local scanning electron microscope images of the electrode region, transition region, and non-electrode region of a solar cell provided in one embodiment of the present disclosure. [Figure 4] Figure 4 shows the three-dimensional structure of the prismatic structure and the micro-protrusion structure in a solar cell provided in one embodiment of the present disclosure. [Figure 5] Figure 5 shows a top view of the bottom of a micro-protrusion structure provided in one embodiment of the present disclosure. [Figure 6] Figure 6 shows another top view structure of the bottom of the micro-protrusion structure provided in one embodiment of the present disclosure. [Figure 7] Figure 7 shows one example of an arrangement of the second pyramidal structure and the first pyramidal structure provided in one embodiment of the present disclosure. [Figure 8] Figure 8 shows another example of the arrangement of the second pyramidal structure and the first pyramidal structure provided in one embodiment of the present disclosure. [Figure 9] Figure 9 shows another local cross-sectional structure of a solar cell provided in one embodiment of the present disclosure. [Figure 10] Figure 10 shows another local cross-sectional structure of a solar cell provided in one embodiment of the present disclosure. [Figure 11]Figure 11 shows another local cross-sectional structure of a solar cell provided in one embodiment of the present disclosure. [Figure 12] Figure 12 shows the local cross-sectional structure of a substrate in a solar cell provided in one embodiment of the present disclosure. [Figure 13] Figure 13 is a scanning electron microscope image of the first doped conductive layer in a solar cell provided in one embodiment of the present disclosure. [Figure 14] Figure 14 is a scanning electron microscope image of the second doped conductive layer in a solar cell provided in one embodiment of the present disclosure. [Figure 15] Figure 15 shows a local cross-sectional structure corresponding to a step in a method for manufacturing a solar cell provided in another embodiment of this disclosure. [Figure 16] Figure 16 shows a local cross-sectional structure corresponding to a step in a method for manufacturing a solar cell provided in another embodiment of this disclosure. [Figure 17] Figure 17 shows a local cross-sectional structure corresponding to a step in a method for manufacturing a solar cell provided in another embodiment of this disclosure. [Figure 18] Figure 18 shows a local cross-sectional structure corresponding to a step in a method for manufacturing a solar cell provided in another embodiment of this disclosure. [Figure 19] Figure 19 shows a local cross-sectional structure corresponding to a step in a method for manufacturing a solar cell provided in another embodiment of this disclosure. [Figure 20] Figure 20 shows a local cross-sectional structure corresponding to a step in a method for manufacturing a solar cell provided in another embodiment of the present disclosure. [Figure 21] Figure 21 shows the structure of a photovoltaic module provided in another embodiment of the present disclosure. [Modes for carrying out the invention]

[0029] From the background technology, it became clear that the photoelectric conversion efficiency of solar cells needs to be improved.

[0030] The analysis revealed that the reason for the current low photoelectric conversion efficiency of solar cells is that a diffusion process is generally used on the substrate surface to convert a portion of the substrate into an emitter. Since the emitter contains different types of doping elements than the substrate, the emitter and the substrate, where the doping elements have not diffused, form a PN junction. This can lead to excessive carrier recombination in the electrode region on the substrate surface, potentially affecting the open-circuit voltage and photoelectric conversion efficiency of the solar cell.

[0031] Embodiments of the present application provide a solar cell, a method for manufacturing the same, and a photovoltaic module. In the solar cell, a first dielectric layer and a first doping conductive layer are arranged in a stacked configuration in the electrode region. The passivation effect of the first dielectric layer and the first doping conductive layer on the electrode region improves the serious carrier recombination problem in the electrode region, thereby increasing the carrier collection efficiency of the electrodes formed on the substrate in the electrode region. On the other hand, by forming the first dielectric layer and the first doping conductive layer only in the electrode region, the first dielectric layer and the first doping conductive layer prevent the absorption of incident light irradiated onto the first surface in the non-electrode region and transient region. Furthermore, since the transient region has at least one row of prismatic structures inclined toward the electrode region, the probability that incident light incident on the transient region at different angles will be absorbed by the transient region via the prismatic structure increases, and the probability that it will be reflected by the non-electrode region via the prismatic structure and absorbed by the non-electrode region also increases, contributing to increasing the absorption rate of incident light on the first surface. Therefore, by improving the serious carrier recombination problem in the electrode region and increasing the absorption rate of the first surface for incident light, the photoelectric conversion efficiency of the solar cell is enhanced.

[0032] The embodiments of this disclosure will be described in detail below with accompanying drawings. However, as those skilled in the art will understand, numerous technical details are proposed in the embodiments of this disclosure in order to help the reader better understand the application. Nevertheless, the technical concepts for which the embodiments of this disclosure seek protection can be realized without these technical details or the various changes and modifications based on the embodiments below.

[0033] One embodiment of the present invention provides a solar cell, and the solar cell provided in one embodiment of the present invention will be described in detail below with reference to the drawings.

[0034] As shown in Figures 1 to 4, the solar cell includes a substrate 100, a first dielectric layer 104 located in an electrode region 101, and a first doping conductive layer 105 located on the side of the first dielectric layer 104 away from the electrode region 101. The substrate 100 has a first surface 110 and a second surface 120 that are placed opposite each other. The first surface 110 includes an electrode region 101 and a non-electrode region 103 that are spaced apart and alternately placed, and a transition region 102 located between the electrode region 101 and the non-electrode region 103. The transition region 102 includes a first surface structure 112, which includes a plurality of prismatic structures 122 that are inclined toward the electrode region 101. The plurality of prismatic structures 122 are arranged sequentially along at least a first direction X, where the first direction X is the direction of extension of the transition region 102.

[0035] Figure 1 shows the local cross-sectional structure of a solar cell provided in one embodiment of the present invention, Figure 2 is a schematic local stereoelectron microscope diagram of the solar cell provided in one embodiment of the present invention, Figure 3 is a magnified electron microscope image of area I in frame 2, and Figure 4 shows the three-dimensional structure of the prismatic structure and micro-protrusion structure in the solar cell provided in one embodiment of the present invention. Furthermore, in order to show the approximate locations of the electrode region 101, the transition region 102, the non-electrode region 103, the first dielectric layer 104, and the first doping conductive layer 105, the surface morphological features of the substrate 100, the first dielectric layer 104, and the first doping conductive layer 105 are not shown in Figure 1.

[0036] As shown in Figure 1, the first surface 110 includes a plurality of electrode regions 101, a plurality of transition regions 102, and a plurality of non-electrode regions 103. The stacked first dielectric layer 104 and the first doping conductive layer 105 are placed on the electrode regions 101, and the first dielectric layer 104 and the first doping conductive layer 105 constitute a passivation contact structure with respect to the electrode regions 101. This improves the serious carrier recombination problem in the electrode regions 101 through the chemical passivation effect of the first dielectric layer 104 on the electrode regions 101 and the field passivation effect of the first doping conductive layer 105 on the electrode regions 101, thereby contributing to improving the collection efficiency of the electrodes formed on the electrode regions 101 with respect to carriers in the substrate 100. On the other hand, by forming the first dielectric layer 104 and the first doping conductive layer 105 only in the electrode region 101, the first dielectric layer 104 and the first doping conductive layer 105 prevent the absorption of the non-electrode region 103 and the transition region 102 to incident light irradiated onto the first surface 110 from decreasing, thereby improving the serious carrier recombination problem in the electrode region 101 and contributing to ensuring a high absorption rate of the first surface 110 to incident light.

[0037] Furthermore, as shown in Figure 3, the first surface structure 112 comprises a plurality of prismatic structures 122 inclined toward the electrode region 101, and the plurality of prismatic structures 122 are sequentially arranged along at least a first direction X, where the first direction X is the direction of extension of the transition region 102. As a result, at least one row of prismatic structures 122 separates the electrode region 101 and the non-electrode region 103 along the first direction X, and this at least one row of prismatic structures 122 is inclined toward the electrode region 101. This increases the probability that incident light incident on the transition region 102 at different angles will be absorbed by the transition region 102 via the prismatic structures 122 by at least one reflection, and also increases the probability that it will be reflected by the non-electrode region 103 via the prismatic structures 122 and absorbed by the non-electrode region 103 by at least one reflection, thereby contributing to increasing the absorption rate of incident light on the first surface 110.

[0038] Therefore, by improving the serious carrier recombination problem in the electrode region 101 and increasing the absorption rate of the first surface 110 for incident light, the photoelectric conversion efficiency of the solar cell is improved.

[0039] In some embodiments, as shown in Figure 3, multiple rows of prismatic structures 122 are arranged along a first direction X, and along the inclination direction of the prismatic structures 122, the average inclination length of the row of prismatic structures 122 closest to the electrode region 101 is greater than the average inclination length of the other rows of prismatic structures 122, and the other rows of prismatic structures 122 are located on the sides of the row of prismatic structures 122 closest to the electrode region 101. This contributes to further increasing the probability that incident light incident on the transition region 102 is absorbed by the transition region 102 or the non-electrode region 103.

[0040] In some embodiments, the electrode region 101 refers to a region in the substrate 100 that is directly facing the electrode or the region where the orthographic projection of the electrode onto the substrate 100 is located, along the thickness direction of the substrate 100. The transition region 102 and the non-electrode region 103 refer to a region in the substrate 100 that is not directly facing the electrode or the region where the orthographic projection of a region other than the electrode onto the substrate 100 is located, and the transition region 102 is located between the electrode region 101 and the non-electrode region 103. In actual applications, the area of ​​the orthographic projection of the electrode region 101 onto the substrate 100 may be greater than or equal to the area of ​​the orthographic projection of the electrode onto the substrate 100, which contributes to ensuring that the entire area in contact between the electrode and the substrate 100 is the electrode region 101.

[0041] The electrodes described above are all electrodes that face directly toward the first surface 110 of the substrate 100, which will be described later. The definitions of the electrode region 101 and the non-electrode region 103 described above are as follows when referring to a non-IBC cell, which will be described later: the two electrodes of different polarities of the solar cell are located on two opposing sides of the substrate 100, and the electrodes described above are electrodes located on the first surface 110. When the solar cell is an IBC cell or when the two conductive electrodes of different polarities are located on the same side of the substrate 100, one electrode region 101 refers to the region that faces directly toward either of the two types of electrodes.

[0042] The embodiments of this application will be described in more detail below with reference to the drawings.

[0043] In some embodiments, as shown in Figures 3 and 4, the prismatic structure 122 includes a first prismatic structure 132 and a second prismatic structure 142, wherein, along the inclination direction of the prismatic structure 122, the first length L1 of the first prismatic structure 132 is greater than the second length L2 of the second prismatic structure 142, and at least a portion of the second prismatic structure 142 is located on the side away from the electrode region 101 of the first prismatic structure 132. This contributes to further increasing the probability that incident light incident on the transition region 102 is absorbed by the transition region 102 or the non-electrode region 103.

[0044] As shown in Figure 4, the first length L1 of the first prism structure 132 can be defined as the inclination length of the shortest of the multiple first prism structures 132, and the second length L2 of the second prism structure 142 can be defined as the inclination length of the longest of the multiple second prism structures 142. Based on this, the fact that the first length L1 of the first prism structure 132 is greater than the second length L2 of the second prism structure 142 means that the inclination length of the shortest of the multiple first prism structures 132 is greater than the inclination length of the longest of the multiple second prism structures 142.

[0045] In practical applications, the first length L1 of the first prism structure 132 can be defined as the average of the inclination lengths of multiple first prism structures 132, and the second length L2 of the second prism structure 142 can be defined as the average of the inclination lengths of multiple second prism structures 142. Based on this, the fact that the first length L1 of the first prism structure 132 is greater than the second length L2 of the second prism structure 142 means that the average of the inclination lengths of multiple first prism structures 132 is greater than the average of the inclination lengths of multiple second prism structures 142.

[0046] Furthermore, in Figure 3, the boundary line between the first prism structure 132 and the second prism structure 142 is depicted with a thicker, denser dotted line. Prism structures 122 with a slope length greater than this dotted line are the first prism structure 132, and prism structures 122 with a slope length less than this dotted line are the second prism structure 142. Note that the definition of the boundary line can be adjusted according to the actual situation.

[0047] In some embodiments, along the inclination direction of the prismatic structure 122, the first length L1 of the first prismatic structure 132 may be 1 μm to 9 μm, and the second length L2 of the second prismatic structure 142 may be 200 nm to 5 μm.

[0048] In some embodiments, as shown in Figure 3, the arrangement of the second prism structures 142 on the side of the first prism structure 132 away from the electrode region 101 includes two situations. In some situations, one second prism structure 142 is located on the side of the first prism structure 132 away from the electrode region 101. In other situations, multiple second prism structures 142 are located on the same side of the first prism structure 132 away from the electrode region 101, and each second prism structure 142 is in contact with and connected to that side.

[0049] In some other embodiments, as shown in Figure 3, a plurality of second prism structures 142 are arranged sequentially along a direction away from the side surface of the first prism structure 132. For example, of the plurality of second prism structures 142, only the second prism structure 142 closest to the side surface of the first prism structure 132 is in contact with and connected to the side surface of the first prism structure 132.

[0050] Furthermore, each of the multiple prismatic structures 122 in the same transition region 102 is at least one of the prismatic structures 122 in the two embodiments described above. That is, each of the multiple prismatic structures 122 in the same transition region 102 may have the characteristics of the prismatic structure 122 in the two embodiments described above, or it may have the characteristics of the prismatic structure 122 in any of the embodiments described above.

[0051] In some embodiments, as shown in Figures 3 and 4, the first surface structure 112 further includes a first pyramidal structure 152, where at least some of the first pyramidal structures 152 are located in a portion of the transition region 102 that is close to the non-electrode region 103. In other words, a portion of the transition region 102 that is close to the non-electrode region 103 contains a more typical first pyramidal structure 152.

[0052] In some embodiments, as shown in Figures 3 and 4, at least some of the prismatic structures 122 are located in a portion of the transition region 102 that is close to the electrode region 101. For example, the prismatic structure 122 is located between the first pyramidal structure 152 and the electrode region 101.

[0053] In some embodiments, as shown in Figures 3 and 4, the first surface structure 112 may further include a plurality of micro-protrusion structures 162, each of which includes at least one of a second pyramidal structure 172 or a triangular plate-like structure 182, where the one-dimensional dimension L3 of the base of the micro-protrusion structure 162 is smaller than the one-dimensional dimension L4 of the base of the first pyramidal structure 152.

[0054] In Figure 3, the micro-protrusion structure 162 is shown as an example in which it includes both the second pyramidal structure 172 and the triangular plate-like structure 182. However, in actual applications, for the first surface structure 112 of the same transition region 102, the micro-protrusion structure 162 may include only one of the second pyramidal structure 172 or the triangular plate-like structure 182. Furthermore, in addition to being either the second pyramidal structure 172 or the triangular plate-like structure 182, the micro-protrusion structure 162 may also be an irregular particulate structure.

[0055] As shown in Figures 4 to 6, the one-dimensional dimension L3 of the base of the micro-protrusion structure 162 is smaller than the one-dimensional dimension L4 of the base of the first pyramidal structure 152. Here, Figure 5 is a diagram showing a top view of the base of the micro-protrusion structure 162 provided in one embodiment of the present application, and Figure 6 is a diagram showing another top view of the base of the micro-protrusion structure 162 provided in one embodiment of the present application. Furthermore, in order to clearly show the features of the first prism structure 132, the second prism structure 142, the first pyramidal structure 152, the second pyramidal structure 172, and the triangular plate-like structure 182, the first prism structure 132, the second prism structure 142, the first pyramidal structure 152, the second pyramidal structure 172, and the triangular plate-like structure 182 in Figure 4 are all drawn using perspective projection.

[0056] As shown in Figure 5, the one-dimensional dimension L3 of the bottom of the micro-protrusion structure 162 includes either the length, width, or diagonal length of the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100. In Figure 5, the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 is shown as a regular rectangle, in which case the one-dimensional dimension L3 of the bottom of the micro-protrusion structure 162 is either the length, width, or diagonal length of the regular rectangle.

[0057] In actual applications, the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 may be an irregular polygon. In this case, the length, width, or diagonal length of the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 is not absolute, but an artificially defined one-dimensional dimension L3 to represent the bottom of the micro-protrusion structure 162. For example, as shown in Figure 6, the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 is an irregular rectangle. In this case, the length L31 of the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 can be defined as the length of the longest side of the irregular rectangle, the width L32 of the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 can be defined as the length of the shortest side of the irregular rectangle, and the length L33 of the diagonal of the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 can be defined as the length of the longest diagonal of the irregular rectangle. However, this is an illustrative explanation, and it can be understood that the specifics can be flexibly defined according to the actual needs.

[0058] Furthermore, the orthographic projection pattern of the bottom of the micro-protrusion structure 162 onto the substrate 100 may be an irregular rectangle, other irregular polygons, a circle, or an irregular shape similar to a circle. In this case, the one-dimensional dimension L3 of the bottom of the micro-protrusion structure 162 can be determined by selecting multiple regions of different specific areas within the bottom of the micro-protrusion structure 162, flexibly defining these specific areas according to actual needs, and then calculating the average value of the length, width, diagonal, or diameter of these different specific areas.

[0059] As shown in Figure 4, the orthographic projection pattern of the base of the first pyramidal structure 152 onto the substrate 100 is generally a regular quadrilateral. In this case, the one-dimensional dimension L4 of the base of the first pyramidal structure 152 is the length, width, or diagonal length of the regular quadrilateral. In actual applications, the orthographic projection pattern of the base of the first pyramidal structure 152 onto the substrate 100 may be an irregular quadrilateral. In this case, the definition of the one-dimensional dimension L3 is similar to that of the case where the orthographic projection pattern of the base of the micro-protrusion structure 162 onto the substrate 100 is an irregular quadrilateral, and therefore does not need to be explained again here.

[0060] Furthermore, the one-dimensional dimensions L4 of the bases of different first pyramidal structures 152 may be different or the same, but the one-dimensional dimensions L4 of the bases of the first pyramidal structures 152 are within a certain numerical range. The one-dimensional dimensions L3 of the bases of different micro-protrusion structures 162 may be different or the same, but the one-dimensional dimensions L3 of the bases of the micro-protrusion structures 162 are also within a certain numerical range. The fact that the one-dimensional dimensions L3 of the bases of the micro-protrusion structures 162 are smaller than the one-dimensional dimensions L4 of the bases of the first pyramidal structures 152 means that the average value of the one-dimensional dimensions L3 of the bases of multiple micro-protrusion structures 162 in the transition region 102 is smaller than the average value of the one-dimensional dimensions L4 of the bases of multiple first pyramidal structures 152 in the transition region 102.

[0061] The following provides a detailed explanation of the specific characteristics of the second pyramidal structure 172.

[0062] In some embodiments, as shown in Figure 7, Figure 7 is an example of an arrangement of a second pyramidal structure 172 and a first pyramidal structure 152 provided in one embodiment of the present application, where the base of the second pyramidal structure 172 is in contact with and connected to the base of the first pyramidal structure 152. In some cases, multiple second pyramidal structures 172 can surround the base of the same first pyramidal structure 152, with the base of each second pyramidal structure 172 being in contact with and connected to the base of this first pyramidal structure 152.

[0063] In some other embodiments, as shown in Figure 8, Figure 8 is another example of an arrangement of the second pyramidal structure 172 and the first pyramidal structure 152 provided in one embodiment of the present application, where at least one second pyramidal structure 172 is located between two adjacent first pyramidal structures 152. In other words, the base of the second pyramidal structure 172 is not in contact with or connected to the base of the first pyramidal structures 152.

[0064] Furthermore, the second pyramidal structure 172 present in the same transition region 102 is at least one of the second pyramidal structures 172 in the two embodiments described above. That is, multiple second pyramidal structures 172 present in the same transition region 102 may each have the characteristics of the second pyramidal structure 172 in the two embodiments described above, or they may each have the characteristics of the second pyramidal structure 172 in any one of the embodiments described above.

[0065] The specific features of the triangular plate-like structure 182 will be described in detail below.

[0066] In some embodiments, as shown in Figure 3, the triangular plate-like structures 182 are located on the sides of the first pyramidal structure 152. The arrangement of the triangular plate-like structures 182 on the sides of the first pyramidal structure 152 includes cases where one triangular plate-like structure 182 is located on the side of the first pyramidal structure 152, and cases where multiple triangular plate-like structures 182 are attached to the same side of one first pyramidal structure 152, and each triangular plate-like structure 182 is in contact with and connected to this side.

[0067] In some other embodiments, as shown in Figure 3, a plurality of triangular plate-like structures 182 are sequentially arranged along a direction away from the side of the first pyramidal structure 152. For example, of the plurality of triangular plate-like structures 182, only the triangular plate-like structure 182 closest to the side of the first pyramidal structure 152 is in contact with and connected to the side of the first pyramidal structure 152.

[0068] Furthermore, each triangular plate-like structure 182 in the same transition region 102 is at least one of the triangular plate-like structures 182 in the two embodiments described above. That is, each of the multiple triangular plate-like structures 182 in the same transition region 102 may have the characteristics of the triangular plate-like structure 182 in the two embodiments described above, or it may have the characteristics of the triangular plate-like structure 182 in any one of the embodiments described above.

[0069] In some embodiments, as shown in Figure 9, Figure 9 is a diagram showing another local cross-sectional structure of a solar cell provided in one embodiment of the present invention, the solar cell may further include a second dielectric layer 114 covering a second surface 120 and a second doping conductive layer 115 covering the surface of the second dielectric layer 114 away from the substrate 100, wherein the type of doping element in the first doping conductive layer 105 is different from the type of doping element in the second doping conductive layer 115.

[0070] As a result, both the front and back surfaces of the substrate 100 can be used to receive incident or reflected light. The first dielectric layer 104 and the first doping conductive layer 105 located on the first surface 110 are used to form a passivation contact structure on the first surface 110, and the second dielectric layer 114 and the second doping conductive layer 115 located on the second surface 120 are used to form a passivation contact structure on the second surface 120. By providing passivation contact structures on both the first surface 110 and the second surface 120, the solar cell becomes a double-sided TOPCON cell. As a result, the passivation contact structures located on the first surface 110 and the second surface 120 play a role in reducing carrier recombination on the first surface 110 and the second surface 120, respectively. Compared to forming a passivation contact structure on only one surface of the substrate 100, this significantly reduces the carrier loss of the solar cell and improves the open-circuit voltage and short-circuit current of the solar cell.

[0071] By forming a passivation contact structure, carrier recombination on the surface of the substrate 100 can be reduced, increasing the open-circuit voltage of the solar cell and improving the photoelectric conversion efficiency of the solar cell.

[0072] Note that in order to show the approximate locations of film layers such as the electrode region 101, transition region 102, non-electrode region 103, first dielectric layer 104, and first doping conductive layer 105 in the double-sided TOPCON cell, Figure 9 does not show the surface morphological features of the substrate 100, the first dielectric layer 104, and the first doping conductive layer 105.

[0073] Depending on the circumstances, the first doping conductive layer 105 and the second doping conductive layer 115 perform a field passivation effect, allowing minority carriers to escape from the interface, thereby lowering the minority carrier concentration and reducing the carrier recombination rate at the interface of the substrate 100. This increases the open-circuit voltage, short-circuit current, and backing factor of the solar cell, thereby improving the photoelectric conversion performance of the solar cell.

[0074] In some embodiments, the materials of the first doped conductive layer 105 and the second doped conductive layer 115 include at least one of silicon carbide, amorphous silicon, microcrystalline silicon, or polycrystalline silicon.

[0075] In some cases, the first dielectric layer 104 and the second dielectric layer 114 are used to achieve interfacial passivation on the surface of the substrate 100, thereby achieving a chemical passivation effect. Specifically, by saturating the dangling bonds on the surface of the substrate 100, the density of interfacial defect levels on the surface of the substrate 100 is reduced, thereby decreasing the number of recombination centers on the surface of the substrate 100.

[0076] In some embodiments, the materials of the first dielectric layer 104 and the second dielectric layer 114 may be dielectric materials, such as silicon oxide, magnesium fluoride, amorphous silicon, polysilicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide, or titanium oxide.

[0077] In some embodiments, the substrate 100 contains doping elements, the type of doping element being N-type or P-type, where the N-type element may be a Group V element such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As), and the P-type element may be a Group III element such as boron (B), aluminum (Al), gallium (Ga), or indium (In). For example, if the substrate 100 is a P-type substrate 100, the type of doping element inside it is P-type, or if the substrate 100 is an N-type substrate 100, the type of doping element inside it is N-type.

[0078] In some embodiments, when the substrate 100 is an N-type substrate 100, the types of doping elements in the first doping conductive layer 105 and the second doping conductive layer 115 include the case where the type of doping element in the first doping conductive layer 105 is N-type and the type of doping element in the second doping conductive layer 115 is P-type, and the case where the type of doping element in the first doping conductive layer 105 is P-type and the type of doping element in the second doping conductive layer 115 is N-type.

[0079] In some embodiments, when the substrate 100 is a P-type substrate 100, the types of doping elements in the first doping conductive layer 105 and the second doping conductive layer 115 also include cases where the type of doping element in the first doping conductive layer 105 is N-type and the type of doping element in the second doping conductive layer 115 is P-type, and cases where the type of doping element in the first doping conductive layer 105 is P-type and the type of doping element in the second doping conductive layer 115 is N-type.

[0080] In some embodiments, the first surface 110 of the double-sided TOPCON cell is the front surface of the substrate 100, and the second surface 120 is the back surface of the substrate 100. The passivation contact structure located on the front surface is installed only in the electrode region 101, while the passivation contact structure located on the back surface is installed across the entire surface. In the embodiments described above, if the type of doping element in the second doping conductive layer 115 differs from the type of doping element in the substrate 100, it is equivalent to having a PN junction on the back surface of the substrate 100, and carrier recombination problems are likely to occur on the back surface of the substrate 100. Therefore, in order to accommodate the installation of different passivation contact structures on the front surface and the back surface of the substrate 100, the thickness of the first dielectric layer 104 can be set to differ from the thickness of the second dielectric layer 114. For example, the thickness of the first dielectric layer 104 may be thinner than the thickness of the second dielectric layer 114. This enhances the chemical passivation effect of the second dielectric layer 114 on the back surface of the substrate 100, further saturates the dangling bonds on the back surface of the substrate 100, reduces the density of interface defect levels on the back surface of the substrate 100, and consequently improves the problem of carrier recombination occurring easily on the back surface of the substrate 100, contributing to an increase in the backing factor, short-circuit current, and open-circuit voltage.

[0081] Furthermore, the type of doping element in the first doping conductive layer 105 is the same as the type of doping element in the substrate 100. This reduces metal contact recombination between the first doping conductive layer 105 and the front electrode when the front electrode subsequently formed in the electrode region 101 comes into electrical contact with the first doping conductive layer 105 on the front surface of the substrate 100, thereby reducing carrier contact recombination and contributing to a reduction in current transmission loss.

[0082] In some embodiments, as shown in Figures 1 and 3, the surface of the first doping conductive layer 105 located in the electrode region 101 comprises a second surface structure 125, the second surface structure 125 comprising a plurality of third pyramidal structures 135.

[0083] Note that since the thickness of the first dielectric layer 104 is sufficiently small compared to the thickness of the first doping conductive layer 105, Figure 3 only shows that the first doping conductive layer 105 is located in the electrode region 101, and does not show the first dielectric layer 104 between the electrode region 101 and the first doping conductive layer 105. Furthermore, both the first dielectric layer 104 located below the first doping conductive layer 105 and the electrode region 101 have the same or similar surface morphology as the first doping conductive layer 105.

[0084] Depending on the case, as shown in Figure 3, the second surface structure 125 mainly includes a third pyramidal structure 135 and further comprises other protruding structures 145, with multiple third pyramidal structures 135 arranged alternately. In actual applications, the arrangement method of the multiple third pyramidal structures 135 is not limited.

[0085] In some embodiments, as shown in Figure 3, the non-electrode region 103 comprises a third surface structure 113, the third surface structure 113 containing a plurality of fourth pyramidal structures 123. In practical applications, the arrangement of the plurality of fourth pyramidal structures 123 is not limited.

[0086] In some embodiments, the one-dimensional dimension L4 of the base of the first pyramidal structure 152 is greater than the one-dimensional dimension of the base of the third pyramidal structure 135, and the one-dimensional dimension of the base of the third pyramidal structure 135 is greater than the one-dimensional dimension of the base of the fourth pyramidal structure 123.

[0087] Furthermore, the one-dimensional dimensions of the base of the third pyramid structure 135 and the one-dimensional dimensions of the base of the fourth pyramid structure 123 are similar to the definition for the one-dimensional dimension L4 of the base of the first pyramid structure 152 in one embodiment of the present invention, so their explanation is omitted here.

[0088] Furthermore, the one-dimensional dimensions of the bases of different third pyramidal structures 135 may be different or the same, but the one-dimensional dimensions of the bases of the third pyramidal structures 135 are within a certain numerical range, and the one-dimensional dimensions of the bases of different fourth pyramidal structures 123 may be different or the same, but the one-dimensional dimensions of the bases of the fourth pyramidal structures 123 are also within a certain numerical range. Based on this, the fact that the one-dimensional dimension L2 of the base of the first pyramidal structure 152 is larger than the one-dimensional dimension of the base of the third pyramidal structure 135 means that the average value of the one-dimensional dimensions L4 of the bases of multiple first pyramidal structures 152 in the transition region 102 is larger than the average value of the one-dimensional dimensions of the bases of multiple third pyramidal structures 135 in the first doping conductive layer 105. The fact that the one-dimensional dimension of the base of the third pyramidal structure 135 is larger than the one-dimensional dimension of the base of the fourth pyramidal structure 123 means that the average value of the one-dimensional dimensions of the bases of multiple third pyramidal structures 135 in the first doping conductive layer 105 is larger than the average value of the one-dimensional dimensions of the bases of multiple fourth pyramidal structures 123 in the non-electrode region 103.

[0089] Furthermore, in one embodiment of the present invention, the relationship between the one-dimensional dimensions of the base of the second pyramid structure 172 and the one-dimensional dimensions of the base of the third pyramid structure 135 is not limited, nor is the relationship between the one-dimensional dimensions of the base of the second pyramid structure 172 and the one-dimensional dimensions of the base of the fourth pyramid structure 123 limited.

[0090] In some embodiments, as shown in Figure 9, the solar cell may further include a front electrode 106 which is electrically connected to a first doping conductive layer 105. A PN junction formed on the back surface of the substrate 100 is used to receive incident light and generate photogenerated carriers, which are transported from the substrate 100 to the first doping conductive layer 105 and then to the front electrode 106. The front electrode 106 is used to collect the photogenerated carriers.

[0091] In some embodiments, the type of doping element in the first doped conductive layer 105 is the same as the type of doping element in the substrate 100, thereby reducing metal contact recombination loss between the front electrode 106 and the first doped conductive layer 105, and consequently lowering carrier contact recombination between the front electrode 106 and the first doped conductive layer 105, thereby improving short-circuit current and the photoelectric conversion performance of the solar cell.

[0092] In some embodiments, the surface of the first doping conductive layer 105 is provided with a second surface structure 125, which increases the contact area between the front electrode 106 and the front surface of the substrate 100, thereby contributing to a reduction in the contact resistance between the front electrode 106 and the front surface of the substrate 100. In other words, the width of the front electrode 106 can be made smaller while maintaining a constant contact resistance between the front electrode 106 and the front surface of the substrate 100, thereby reducing the shielding of the front electrode 106 from incident light and increasing the absorption capacity of the substrate 100 from incident light.

[0093] In some embodiments, as shown in Figure 9, the solar cell may include a back electrode 116, the back electrode 116 located on the back surface of the substrate 100, and the back electrode 116 is in electrical contact with the second doping conductive layer 115.

[0094] In some embodiments, as shown in Figure 9, the solar cell may further include a first passivation layer 107 that covers the surfaces of the transition region 102 and the non-electrode region 103, and also covers the surfaces of the stacked first dielectric layer 104 and the first doping conductive layer 105. The front electrode 106 penetrates the first passivation layer 107 and is in electrical contact with the first doping conductive layer 105.

[0095] In some embodiments, as shown in Figure 9, the solar cell may further include a second passivation layer 117, which covers the surface of the second doping conductive layer 115 away from the second dielectric layer 114. The back electrode 116 penetrates the second passivation layer 117 and is electrically connected to the second doping conductive layer 115.

[0096] In some embodiments, the first passivation layer 107 and the second passivation layer 117 may both be single-layer or multi-layer structures, and the material of the first passivation layer 107 and the material of the second passivation layer 117 may both be at least one of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0097] The following will explain in detail using solar cells as an example.

[0098] In some embodiments, as shown in Figure 10, the solar cell further includes an intrinsic semiconductor layer 214 covering a second surface 220, a second doping conductive layer 215 covering the surface of the intrinsic semiconductor layer 214 away from the substrate 200, and a transparent conductive layer 207 covering the surface of the second doping conductive layer 215 away from the intrinsic semiconductor layer 214, wherein the type of doping element in the first doping conductive layer 205 is different from the type of doping element in the second doping conductive layer 215.

[0099] Note that the substrate 200, first surface 210, second surface 220, electrode region 201, transition region 202, non-electrode region 203, first dielectric layer 204, first doping conductive layer 205, and front electrode 206 in Figure 10 are all similar to the corresponding configurations in the above-described embodiment, and therefore their explanation is omitted here. Furthermore, the surface morphologies of the first surface 210, second surface 220, first dielectric layer 204, and first doping conductive layer 205 are also similar to the corresponding surface morphologies in the above-described embodiment, and therefore their explanation is omitted here.

[0100] Furthermore, in order to show the approximate locations of film layers such as the electrode region 201, transition region 202, non-electrode region 203, first dielectric layer 204, and first doping conductive layer 205 in the HJT cell, Figure 10 does not show the surface morphological features of the substrate 200, the first dielectric layer 204, and the first doping conductive layer 205.

[0101] In some embodiments, the interface where the intrinsic semiconductor layer 214 contacts the substrate 200 can increase the open-circuit voltage of the solar cell while also enhancing the passivation effect on the substrate 200, thereby contributing to an increase in the photoelectric conversion efficiency of the solar cell.

[0102] In some embodiments, the material of the intrinsic semiconductor layer 214 includes intrinsic amorphous silicon, silicon oxide, silicon nitride, or silicon carbide. In some embodiments, the thickness of the intrinsic semiconductor layer is 2 μm to 10 μm, for example, the thickness of the intrinsic semiconductor layer is 5 μm.

[0103] In some embodiments, the material of the second doping conductive layer 215 includes a composite thin film layer in which one or more of the following are laminated: N-type doped or P-type doped amorphous silicon, amorphous silicon oxide, amorphous silicon carbide, microcrystalline silicon, hydrogenated microcrystalline silicon, microcrystalline silicon oxide, microcrystalline silicon carbide, or polycrystalline silicon semiconductor thin films.

[0104] In some embodiments, the thickness of the second doping conductive layer 215 is 4 nm to 500 nm. Furthermore, the thickness range of the second doping conductive layer 215 is 200 nm to 400 nm, and for example, the thickness of the second doping conductive layer 215 may be 20 nm to 103 nm, 103 nm to 139 nm, 139 nm to 161 nm, 161 nm to 218 nm, 218 nm to 298 nm, or 298 nm to 500 nm.

[0105] In some embodiments, the second doping conductive layer 215 contains hydrogenated microcrystalline silicon, which contributes to giving the second doping conductive layer 215 a larger band gap and a narrower absorption spectral range, thereby effectively increasing the photoelectric conversion efficiency of the solar cell. Furthermore, as the crystallinity is improved, the series resistance decreases and the backing factor increases, which improves the output current of the battery and effectively extends the battery life.

[0106] In some embodiments, the material of the transparent conductive layer 207 may include at least one of tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), cerium-doped indium oxide, and tungsten-doped indium oxide.

[0107] In some embodiments, a PN junction is formed between the second doping conductive layer 215 and the substrate 200. An intrinsic semiconductor layer 214 is inserted as a buffer layer between the PN junctions, and the intrinsic semiconductor layer 214 has a good passivation effect on the surface of the substrate 200, which can significantly prevent carrier recombination and contribute to improving minority carrier lifetime and the open-circuit voltage of the solar cell.

[0108] In some embodiments, as shown in Figure 10, the solar cell may further include a back electrode 216, the back electrode 216 being in electrical contact with the transparent conductive layer 207.

[0109] In some cases, the transparent conductive layer 207 is conductive, and carriers can sequentially pass through the intrinsic semiconductor layer 214, the second doping conductive layer 215, and the transparent conductive layer 207, and finally be collected on the back electrode 216.

[0110] The following will explain in detail using solar cells as an example.

[0111] In some embodiments, as shown in Figure 11, Figure 11 is a diagram showing another local cross-sectional structure of a solar cell provided in one embodiment of the present application, wherein the electrode region 301 is a positive electrode region 311 or a negative electrode region 321, the first dielectric layer 304 includes a first sub-dielectric layer 314 located in the positive electrode region 311 and a second sub-dielectric layer 324 located in the negative electrode region 321, the first doping conductive layer 305 includes a first sub-doping conductive layer 315 located on the side of the first sub-dielectric layer 314 closer to the positive electrode region 311 and a second sub-doping conductive layer 325 located on the side of the second sub-dielectric layer 324 closer to the negative electrode region 321, wherein the type of doping element in the first sub-doping conductive layer 315 is different from the type of doping element in the second sub-doping conductive layer 325.

[0112] Note that the substrate 300, first surface 310, second surface 320, transition region 302, and non-electrode region 303 in Figure 11 are all similar to the corresponding structures in the embodiments described above, so their explanation is omitted here. However, the surface morphology of the first surface 310 differs from that of the embodiments described above.

[0113] Furthermore, in order to show the approximate locations of film layers such as the electrode region 301, transition region 302, non-electrode region 303, first dielectric layer 304, and first doping conductive layer 305 in the IBC cell, Figure 11 does not show the surface morphological features of the substrate 300, the first dielectric layer 304, and the first doping conductive layer 305.

[0114] In some embodiments, the first surface 310 in the IBC cell is the back surface of the substrate 300, and the second surface 320 is the front surface of the substrate 300.

[0115] In some embodiments, the substrate 300 also contains doping elements, the type of doping element in the first sub-doping conductive layer 315 is different from the type of doping element in the substrate 300, and the type of doping element in the second sub-doping conductive layer 325 is the same as the type of doping element in the substrate 300.

[0116] In some embodiments, as shown in Figure 12, which is a diagram showing the local cross-sectional structure of a substrate 300 in a solar cell provided in one embodiment of the present invention, the electrode region 301 comprises a fourth surface structure 331, the fourth surface structure 331 comprises a plurality of platform ridge structures 341, the non-electrode region 303 comprises a fifth surface structure 313, the fifth surface structure 313 comprises a plurality of fifth pyramidal structures 323, where the one-dimensional dimension L4 (see Figure 4) of the base of the first pyramidal structure 152 (see Figure 4) is greater than the one-dimensional dimension of the base of the fifth pyramidal structure 323.

[0117] Furthermore, the surface morphology of the transition region 302 in the IBC cell shown in Figures 11 and 12 is similar to the corresponding surface morphology in the embodiment described above, so its explanation is omitted here. Also, the surface morphology of the transition region 302 is not shown in Figures 11 and 12. Therefore, the one-dimensional dimension L4 of the bottom of the first pyramidal structure 152 (see Figure 4) here adopts the notation used in the embodiment described above.

[0118] Furthermore, the one-dimensional dimension of the base of the fifth pyramidal structure 323 is similar to the definition for the one-dimensional dimension L4 of the base of the first pyramidal structure 152 in one embodiment of the present invention, so its explanation is omitted here. Also, the one-dimensional dimensions of the bases of different fifth pyramidal structures 323 may be different or the same, but the one-dimensional dimensions of the bases of the fifth pyramidal structures 323 are within a certain numerical range, and based on this, the fact that the one-dimensional dimension L4 of the base of the first pyramidal structure 152 is greater than the one-dimensional dimension of the base of the fifth pyramidal structure 323 means that the average value of the one-dimensional dimensions of the bases of multiple first pyramidal structures in the transition region 302 is greater than the average value of the one-dimensional dimensions of the bases of multiple fifth pyramidal structures 323 in the non-electrode region 303.

[0119] In some embodiments, the platform raised structure 341 is the structure remaining after removing the base portion of the pyramid structure, i.e., the tip portion of the pyramid structure. In other words, compared to a complete pyramid structure, the surface morphology of the electrode region 301 is relatively flat, and the first dielectric layer 304 and the first doping conductive layer 305 formed on the electrode region 301 also have a flat morphology, which can increase the uniformity of the formed first dielectric layer 304 and first doping conductive layer 305, improve the passivation effect of the first dielectric layer 304 and first doping conductive layer 305 on the electrode region 301, and contribute to further reducing the defect level density of the electrode region 301.

[0120] In the various embodiments described above, as shown in Figure 2, the electrode region 101 has a first upper surface, and the non-electrode region 103 has a second upper surface. With respect to the second surface 120 (see Figure 1), the first upper surface is higher than the second upper surface, and the height difference H between the first upper surface and the second upper surface is 0.5 μm to 10 μm.

[0121] The first upper surface of the electrode region 101 is composed of the tip portions of multiple third pyramidal structures 135 (see Figure 3). Based on the different dimensions of the different third pyramidal structures 135, this first upper surface is a plane composed of the tip portions of most of the third pyramidal structures 135 in the electrode region 101, and the proportion of the electrode region 101 occupied by most of the third pyramidal structures 135 can be flexibly selected depending on the actual situation. Similarly, the second upper surface of the non-electrode region 103 is composed of the tip portions of multiple fourth pyramidal structures 123 (see Figure 3).

[0122] Depending on the circumstances, the height difference H between the first upper surface and the second upper surface may be 3 μm to 4 μm, and for example, H may be 3.5 μm.

[0123] In some embodiments, Figure 13 is a scanning electron microscope image of a first doping conductive layer in a solar cell provided in one embodiment of the present invention, and Figure 14 is a scanning electron microscope image of a second doping conductive layer in a solar cell provided in one embodiment of the present invention. As shown in Figures 13 and 9, in a double-sided TOPCON cell, if the type of doping element in the first doping conductive layer 105 is N-type and the type of doping element in the second doping conductive layer 115 is P-type, the first doping conductive layer 105 comprises a plurality of first silicon crystal particles 1121, the surfaces of which have a first roughness.

[0124] In some cases, the material of the first doping conductive layer 105 is doped polycrystalline silicon. In the process of forming the first doping conductive layer 105, silicon atoms are arranged in a diamond lattice in the form of numerous crystal nuclei. These crystal nuclei grow into crystal grains with different crystal plane orientations, and these crystal grains are bonded together to crystallize as polycrystalline silicon. Here, the first silicon crystal grains refer to crystal grains with different crystal plane orientations that constitute polycrystalline silicon.

[0125] The scanning electron microscope image in Figure 13 allows for an intuitive observation of the surface morphology of the first doping conductive layer 105. The first doping conductive layer 105 is composed of a plurality of first silicon crystal particles 1121, and the irregularities of the plurality of first silicon crystal particles 1121 constitute the uneven surface of the first doping conductive layer 105, thereby giving the surface of the first doping conductive layer 105 a first roughness.

[0126] In some embodiments, the grain size range of the first silicon crystal grains 1121 is 10 nm to 300 nm. The grain size of the first silicon crystal grains 1121 may be 10 nm to 53 nm, 53 nm to 95.3 nm, 95.3 nm to 138.2 nm, 138.2 nm to 200.6 nm, 200.6 nm to 248 nm, or 248 nm to 300 nm. The grain size of the first silicon crystal grains 1121 is within the above arbitrary range so that the surface roughness of the surface composed of the first silicon crystal grains 1121 is increased. When the grain size of the first silicon crystal grains 1121 is within the above arbitrary range, the stability between adjacent first silicon crystal grains 1121 is good, and crystalline deformation of the first doping conductive layer 105 is less likely to occur. Furthermore, the grain size of the first silicon crystal grains 1121 is within the range described above, resulting in low stress on the first dielectric layer 104 by the first doping conductive layer 105, and improving the film layer performance between the first doping conductive layer 105 and the first dielectric layer 104.

[0127] In some embodiments, the shape of the first silicon crystal grains 1121 includes particulate. Compared to a bulk structure, there are fewer grain boundaries between particulate grains and larger spaces between grain boundaries, allowing the N-type doping elements in the first doping conductive layer 105 to migrate through the spaces between grain boundaries and ultimately be collected on the front electrode 106.

[0128] In some examples, particulate matter includes spherical or quasi-spherical particulate matter.

[0129] In some embodiments, the thickness of the first dielectric layer 104 is 0.5 nm to 5 nm. The thickness range of the first dielectric layer 104 is 0.5 nm to 1.3 nm, 1.3 nm to 2.6 nm, 2.6 nm to 4.1 nm, or 4.1 nm to 5 nm. When the first dielectric layer 104 is within any of the above ranges, the thickness of the first dielectric layer 104 is thin, allowing majority carriers to easily quantum tunnel through the first dielectric layer 104, while minority carriers have difficulty passing through the first dielectric layer 104, thereby achieving selective carrier transport.

[0130] In some embodiments, the thickness of the first doping conductive layer 105 is 10 nm to 300 nm. For example, the thickness of the first doping conductive layer 105 may be 10 nm to 60 nm, 60 nm to 130 nm, 130 nm to 250 nm, or 250 nm to 300 nm.

[0131] As shown in Figures 9 and 14, the second doping conductive layer 115 is doped with a P-type doping element, and the surface of the second doping conductive layer 115 away from the second dielectric layer 114 has a second roughness, which is smaller than the first roughness.

[0132] In some embodiments, the second doping conductive layer 115 includes a plurality of second silicon particles 1221, the surfaces of the plurality of second silicon particles 1221 constitute the surface of the second doping conductive layer 115 having a second roughness, and the grain size of the first silicon crystal particles 1121 is smaller than the grain size of the second silicon particles 1221.

[0133] In some cases, "roughness" in "first roughness and second roughness" refers to the arithmetic mean of the absolute values ​​of the vertical deviations of peaks and valleys with respect to the mean horizontal line, which is set along the sampled length. Roughness can be measured by comparison methods, light section methods, interferometry, and probe scanning methods.

[0134] In some embodiments, the grain size range of the second silicon particles 1221 is 100 nm to 900 nm. The grain size of the second silicon particles 1221 may be 100 nm to 250 nm, 250 nm to 360 nm, 360 nm to 490 nm, 490 nm to 584 nm, 584 nm to 610 nm, 610 nm to 790 nm, or 790 nm to 900 nm. When the grain size of the second silicon particles 1221 is within any of the above ranges, the grain boundaries between adjacent second silicon particles 1221 are small, allowing carriers to pass through the second doping conductive layer 115 relatively easily, increasing the carrier migration speed and contributing to improved battery efficiency.

[0135] In some embodiments, the shape of the second silicon particles 1221 may be sheet-like, plate-like, or particulate. The micromorphology of the second silicon particles 1221 shown in Figure 14 is sheet-like.

[0136] Figures 13 and 14 show the surface morphology of the first doping conductive layer 105 (see Figure 9) and the second doping conductive layer 115 (see Figure 9) at the same magnification. As can be seen, the surface of the first doping conductive layer 105 is rougher than the surface of the second doping conductive layer 115, i.e., the roughness of the first layer is greater than that of the second layer. As a result, based on the difference in morphology between the first doping conductive layer 105 and the second doping conductive layer 115, the surface of the first doping conductive layer 105, which has a higher roughness, can increase the internal reflection of incident light and reduce the optical loss of the solar cell. In addition, the first doping conductive layer 105 can increase the contact area between the front electrode 106 and the first doping conductive layer 105, thereby improving the contact performance and soldering tensile strength of the first doping conductive layer 105. For a second doping conductive layer 115 having low roughness, the surface of the second doping conductive layer 115 is smooth, the uniformity of the passivation layer deposited thereon is good, and the passivation performance of the passivation layer is good, which can improve recombination defects in the solar cell.

[0137] The shapes of the first silicon crystal grains 1121 and the second silicon grains 1221 are observed using a measuring means equipped with magnification, such as an electron microscope or an optical microscope. The electron microscope includes scanning electron microscopes (SEM) or atomic force microscopes (AFM), which are common measuring means. Figure 13 is a micromorphological diagram of the first silicon crystal grains 1121 obtained by scanning electron microscopy, and as can be seen, the first silicon crystal grains 1121 exhibit a particulate structure with equal lengths in the three-dimensional direction. Figure 14 is a micromorphological diagram of the second silicon grains 1221 obtained by scanning electron microscopy, and as can be seen, the second silicon grains 1221 exhibit a sheet-like structure extending in the two-dimensional direction.

[0138] In some embodiments, as shown in Figures 13 and 14, the grain size of the first silicon crystal particles 1121 is smaller than that of the second silicon particles 1221. This means that the radial one-dimensional dimension of the first silicon crystal particles 1121 is smaller than that of the second silicon particles 1221, and the height of the first silicon crystal particles 1121 is greater than that of the second silicon particles 1221. As a result, the roughness of the first doping conductive layer 105 composed of the first silicon crystal particles 1121 is greater than the roughness of the second doping conductive layer 115 composed of the second silicon particles 1221.

[0139] Depending on the context, the radial one-dimensional dimension of the first silicon crystal particle 1121 refers to the average line length (or diameter) of the first silicon crystal particle 1121, and the height of the first silicon crystal particle 1121 refers to the distance between the side of the first silicon crystal particle 1121 closer to the first dielectric layer 104 and the side of the first silicon crystal particle 1121 further away from the first dielectric layer 104.

[0140] Similarly, the radial one-dimensional dimension of the second silicon particle 1221 refers to the average line length (or diameter) of the second silicon particle 1221, and the height of the second silicon particle 1221 refers to the distance between the side of the second silicon particle 1221 that is close to the second dielectric layer 114 and the side of the second silicon particle 1221 that is far from the second dielectric layer 114.

[0141] In some embodiments, the thickness of the second dielectric layer 114 is 0.5 nm to 5 nm. The thickness range of the second dielectric layer 114 is 0.5 nm to 1.3 nm, 1.3 nm to 2.6 nm, 2.6 nm to 4.1 nm, or 4.1 nm to 5 nm. When the thickness of the second dielectric layer 114 is within any of the above ranges, the second dielectric layer 114 is thin, allowing majority carriers to easily quantum tunnel through the second dielectric layer 114, while minority carriers have difficulty passing through the second dielectric layer 114, thereby achieving selective carrier transport.

[0142] In some embodiments, the shape of the first silicon crystal grain 1121 is three-dimensionally equilateral particulate, and the height of the first silicon crystal grain 1121 is equal to the average linear length of the first silicon crystal grain 1121; the shape of the second silicon grain 1221 is two-dimensionally elongated sheet-like, and the height of the second silicon grain 1221 is less than the average linear length of the second silicon grain 1221. The height of the second silicon grain 1221 is the linear length in the non-extended plane direction.

[0143] Here, the size of the crystal grains is called grain size. Common methods of expression include the number of crystal grains per unit volume (ZV), the number of crystal grains per unit area (ZS), or the average linear length (or diameter) of the crystal grains. The average linear length of a crystal grain refers to the linear length of the extending surface in the direction of grain extension. In the embodiments of this application, the grain size may also be the average linear length of the crystal grains.

[0144] In the HJT cell shown in Figure 10, if the doping element type in the first doping conductive layer 205 is N-type and the doping element type in the second doping conductive layer 215 is P-type, then the first doping conductive layer 205 also contains a plurality of first silicon crystal particles 1121, and the surfaces of the plurality of first silicon crystal particles 1121 have a first roughness. Similarly, the second doping conductive layer 115 also contains a plurality of second silicon particles 1221, and the surfaces of the plurality of second silicon particles 1221 have a second roughness. The relationship between the second roughness and the first roughness, and the relationship between the first silicon crystal particles 1121 and the second silicon particles 1221 are similar to the corresponding features in the double-sided TOPCON cell described above, so their explanation is omitted here.

[0145] Similarly, in the IBC cell shown in Figure 11, the first doping conductive layer 305 includes a first sub-doping conductive layer 315 and a second sub-doping conductive layer 325. If one of the doping elements in the first sub-doping conductive layer 315 and the second sub-doping conductive layer 325 is N-type and the other is P-type, then based on this, the doping conductive layer doped with the N-type doping element also includes a plurality of first silicon crystal particles 1121, the surfaces of which have a first roughness, and the doping conductive layer doped with the P-type doping element also includes a plurality of second silicon particles 1221, the surfaces of which have a second roughness. The relationship between the second roughness and the first roughness, and the relationship between the first silicon crystal particles 1121 and the second silicon particles 1221 are similar to the corresponding features in the double-sided TOPCON cell described above, so a detailed explanation is omitted here.

[0146] As described above, the stacked first dielectric layer 104 and the first doping conductive layer 105 are placed in the electrode region 101, and the passivation effect of the first dielectric layer 104 and the first doping conductive layer 105 on the electrode region 101 improves the serious carrier recombination problem in the electrode region 101, thereby improving the collection efficiency of the electrodes formed in the electrode region 101 with respect to carriers in the substrate 100. On the other hand, by forming the first dielectric layer 104 and the first doping conductive layer 105 only in the electrode region 101, the first dielectric layer 104 and the first doping conductive layer 105 prevent the absorption of incident light irradiated onto the first surface 110 by the non-electrode region 103 and the transition region 102 from being reduced. Furthermore, by providing the first surface structure 112 with multiple prismatic structures 122 that are inclined toward the electrode region 101, the probability that incident light incident on the transition region 102 at different angles will be absorbed by the transition region 102 via the prismatic structures 122 through at least one reflection, and the probability that it will be reflected by the non-electrode region 103 via the prismatic structures 122 through at least one reflection and absorbed by the non-electrode region 103, is increased, contributing to an increase in the absorption rate of the first surface 110 for incident light. This improves the serious carrier recombination problem in the electrode region 101 and increases the absorption rate of the first surface 110 for incident light, thereby increasing the photoelectric conversion efficiency of the solar cell.

[0147] Another embodiment of the present application further provides a method for manufacturing a solar cell for producing the solar cell provided in the embodiment described above. The method for manufacturing a solar cell provided in the other embodiment of the present application will be described in detail below with reference to the drawings. Note that the same or corresponding parts as in the embodiment described above will not be described here.

[0148] Figures 15 to 20 show local cross-sectional structures corresponding to each step in a method for manufacturing a solar cell provided in another embodiment of the present application.

[0149] As shown in Figures 15 to 20, the method for manufacturing a solar cell includes at least the following steps.

[0150] Step S11: As shown in Figure 15, an initial substrate 130 is provided, comprising an initial first surface 140 and an initial second surface 150 which are placed opposite each other, and including an initial electrode region 191 and an initial non-electrode region 193 which are spaced apart and alternately placed on the initial first surface 140, and an initial transition region 192 located between the initial electrode region 191 and the initial non-electrode region 193.

[0151] In some embodiments, the process may further include a first etching step on the initial first surface 140 before forming the subsequent initial first dielectric layer, thereby giving the initial first surface 140 a first texture structure, i.e., the surfaces of the initial electrode region 191, initial transition region 192, and initial non-electrode region 193 all having a similar texture structure, which may be a pyramidal structure. The first etching step may include chemical etching, for example, cleaning the surface of the initial substrate 130 with a mixed solution of potassium hydroxide and hydrogen peroxide, specifically controlling the concentration ratio of potassium hydroxide and hydrogen peroxide to form an initial first surface 140 with a desired morphology. In some other embodiments, the texture formation process may be performed by methods such as laser etching, mechanical methods, or plasma etching.

[0152] Step S12: An initial first dielectric layer is formed to cover the initial first surface 140. Step S13: An initial first doping conductive layer is formed to cover the surface of the initial first dielectric layer away from the initial substrate 130. Step S14: The initial first dielectric layer and the initial first doping conductive layer located in the initial transition region 192 and initial non-electrode region 193 are removed by laser process to form a substrate 100 having a first surface 110.

[0153] Steps S12 to S14 differ to some extent in order to form different types of batteries, and these will be explained in detail below.

[0154] Here, as shown in Figures 15 and 1 to 4, the initial electrode region 191, initial transition region 192, and initial non-electrode region 193 after processing by the laser process are electrode region 101, transition region 102, and non-electrode region 103, respectively, the transition region 102 comprises a first surface structure 112, the first surface structure 112 includes a plurality of prismatic structures 122 inclined toward the electrode region 101, the plurality of prismatic structures 122 are sequentially arranged at least along a first direction X, the first direction X is the direction of extension of the transition region 102, the remaining initial first dielectric layer located in the electrode region 101 is the first dielectric layer 104, and the remaining initial first doping conductive layer located in the electrode region 101 is the first doping conductive layer 105.

[0155] The following describes steps S12 to S14 in detail, using the formation of a double-sided TOPCON cell as an example.

[0156] In step S12, an initial first dielectric layer 154 is formed to cover the initial first surface 140, as shown in Figure 16.

[0157] In some embodiments, as shown in Figure 16, the step of forming the initial first dielectric layer 154 may further include forming a second dielectric layer 114 that covers the initial second surface 150. This not only eliminates process steps by forming the initial first dielectric layer 154 and the second dielectric layer 114 in the same process step, but also reduces the number of coding removal steps compared to forming the initial first dielectric layer 154 and the second dielectric layer 114 separately.

[0158] In some cases, if the initial first dielectric layer 154 is formed on the initial first surface 140 first, it is necessary to first form a protective layer on the initial second surface 150 so that the formation step of the initial first dielectric layer 154 does not affect the initial second surface 150. Also, in the process step of forming the initial first dielectric layer 154, a coating is formed on the side surface of the initial substrate 130, and after the formation of the initial first dielectric layer 154, it is necessary to perform a first coating removal process on the side surface of the initial substrate 130. After the first coating removal process, the second dielectric layer 114 is formed on the initial second surface 150. In order to prevent the formation step of the second dielectric layer 114 from affecting the initial first surface 140, it is necessary to first form a protective layer on the initial first surface 140, and since the formation step of the second dielectric layer 114 forms a coating on the side surface of the initial substrate 130, it is necessary to perform a second coating removal process after the formation of the second dielectric layer 114.

[0159] In some cases, the coating removal step requires cleaning the coating formed on the sides of the initial substrate 130 using a wet chemical method. In other words, the coating removal step not only removes the coating but also, because it employs a wet chemical method, can damage the initial substrate 130. In one embodiment of the present invention, by simultaneously forming the initial first dielectric layer 154 and the second dielectric layer 114, the steps of forming protective layers on the initial first surface 140 and the initial second surface 150 can be omitted. Furthermore, after forming the initial first dielectric layer 154 and the second dielectric layer 114, only one coating removal step is required, significantly simplifying the process steps and increasing process efficiency. In addition, since there is no need to form protective layers on the initial first surface 140 and the initial second surface 150, there is no need to remove the protective layer later, thus avoiding process damage to the initial substrate 130 caused by the protective layer removal step and maintaining the good performance of the initial substrate 130.

[0160] In step S13, as shown in Figure 16, an initial first doping conductive layer 155 is formed that covers the surface of the initial first dielectric layer 154 on the side away from the initial substrate 130.

[0161] In some embodiments, as shown in Figure 16, the step of forming the initial first doping conductive layer 155 may further include forming a second doping conductive layer 115 that covers the surface of the second dielectric layer 114 away from the initial substrate 130, and the type of doping element in the initial first doping conductive layer 155 is different from the type of doping element in the second doping conductive layer 115. Subsequently, since the first doping conductive layer 105 (see Figure 9) is formed based on the initial first doping conductive layer 155, the type of doping element in the first doping conductive layer 105 is different from the type of doping element in the second doping conductive layer 115.

[0162] By forming the initial first doping conductive layer 155 and the second doping conductive layer 115 in the same process step, not only can process steps be eliminated, but the number of coating removal cycles can also be reduced compared to forming the initial first doping conductive layer 155 and the second doping conductive layer 115 separately.

[0163] In some embodiments, forming the initial first doping conductive layer 155 and the second doping conductive layer 115 may include the following steps:

[0164] The first deposition process is performed simultaneously on the initial first surface 140 and the initial second surface 150 so as to form a first amorphous silicon layer on the surface of the initial first dielectric layer 154 away from the initial substrate 130, and a second amorphous silicon layer on the surface of the second dielectric layer 114 away from the initial substrate 130. For example, the first amorphous silicon layer and the second amorphous silicon layer can be formed by plasma chemical vapor deposition.

[0165] The first amorphous silicon layer and the second amorphous silicon layer are simultaneously crystallized to convert the first amorphous silicon layer into a first polycrystalline silicon layer and the second amorphous silicon layer into a second polycrystalline silicon layer. In some embodiments, the crystallization process includes annealing the first amorphous silicon layer and the second amorphous silicon layer, with an annealing temperature of 800°C to 1200°C. Within this temperature range, the annealing temperature is not too low, ensuring sufficient crystallization of the first amorphous silicon layer and the second amorphous silicon layer, while the annealing temperature is not too high, preventing the problem of excessively high annealing temperatures damaging the initial substrate 130.

[0166] After forming the first polycrystalline silicon layer and the second polycrystalline silicon layer, a first doping step is performed on the first polycrystalline silicon layer to form an initial first doped conductive layer 155. In some embodiments, the doping elements in the first doping step diffuse into some of the initial substrate 130, forming a diffusion region. The concentration of the doping elements in the diffusion region becomes higher than the concentration of the doping elements in the remaining initial substrate 130. That is, the diffusion region is a high-concentration doped region compared to the remaining initial substrate 130. This high-concentration doped region forms a high-low junction with the remaining initial substrate 130. The presence of this high-low junction creates a barrier effect for carriers, increasing the transport rate and quantity of carriers in the substrate 100 to the diffusion region, allowing the later-formed first doped conductive layer to effectively collect carriers.

[0167] In some embodiments, the process may further include forming a first mask layer on the surface of the second polycrystalline silicon layer away from the initial substrate 130 before performing the first doping step, and further including removing the first mask layer before forming the second doping conductive layer. Since the first doping step and the second doping step performed later on the second polycrystalline silicon layer are performed in different process steps, forming the first mask layer on the surface of the second polycrystalline silicon layer before performing the first doping step helps to protect the second polycrystalline silicon layer from the first doping step.

[0168] In some embodiments, the first doping step may be either an ion implantation step or a source diffusion step.

[0169] In some embodiments, after forming an initial first doping conductive layer 155, the first mask layer is removed in an etching step, and the etching step includes either a dry etching step, a wet etching step, or a laser etching step.

[0170] After the first doping step, the second doping step is performed on the second polycrystalline silicon layer to form the second doped conductive layer 115. In some embodiments, the type of doping element in the second doped conductive layer 115 differs from the type of doping element in the initial substrate 130, thereby forming a PN junction between the second doped conductive layer 115 and the later-formed substrate 100 (see Figure 9), creating a back contact structure. Since the entire surface of the second doped conductive layer 115 is formed on the back surface of the substrate 100, the area of ​​the PN junction is increased, and the number of photogenerated carriers generated at the PN junction increases. At the same time, the electrostatic field formed on the second doped conductive layer 115 facing the back surface of the substrate 100 becomes larger, which is advantageous for carrier movement and can increase the open-circuit voltage and short-circuit current. Furthermore, forming the PN junction on the back surface prevents the serious carrier recombination problem in the electrode region 101 on the front surface of the substrate 100 that would occur if the PN junction were formed on the front surface of the substrate 100, and can improve the double-sided ratio.

[0171] In some embodiments, the second doping step may be either an ion implantation step or a source diffusion step.

[0172] In step S14, as shown in Figures 16 and 1, the initial first dielectric layer 154 and initial first doping conductive layer 155 in the initial transition region 192 and initial non-electrode region 193 are removed by laser process to form a substrate 100 having a first surface 110.

[0173] In some embodiments, the initial first surface 140 has a first texture structure, and in the step of removing the initial first dielectric layer 154 and initial first doping conductive layer 155 located in the initial transition region 192 and initial non-electrode region 193 by a laser process, as shown in Figures 16, 9 and 3, the first doping conductive layer 105 located in the initial electrode region 191 has a second surface structure 125, the first texture structure located in the initial transition region 192 is converted to a first surface structure 112, and the initial non-electrode region 193 is located The first texture structure is transformed into a third surface structure 113, where the first surface structure 112 includes a plurality of first pyramidal structures 152, the second surface structure 125 includes a plurality of third pyramidal structures 135, and the third surface structure 113 includes a plurality of fourth pyramidal structures 123, where the one-dimensional dimension of the base of the first pyramidal structure 152 is greater than the one-dimensional dimension of the base of the third pyramidal structure 135, and the one-dimensional dimension of the base of the third pyramidal structure 135 is greater than the one-dimensional dimension of the base of the fourth pyramidal structure 123.

[0174] Furthermore, the first surface structure 112 can be fine-tuned by adjusting the process parameters of the laser process.

[0175] Steps S12 to S14 will be explained in detail below, using the formation of an HJT cell as an example.

[0176] As shown in Figure 10, the steps for forming the substrate 200, the first dielectric layer 204, and the first doping conductive layer 205 in the HJT cell are similar to the steps for forming the substrate 100, the first dielectric layer 104, and the first doping conductive layer 105 in the double-sided TOPCON cell described above, so a detailed explanation is omitted here.

[0177] The main differences in the formation steps are as follows:

[0178] In some embodiments, as shown in Figure 17, it may further include forming an intrinsic semiconductor layer 214 covering an initial second surface 250 before forming an initial first doping conductive layer 255, and in the step of forming the initial first doping conductive layer 255, it may further include forming a second doping conductive layer 215 covering the surface of the intrinsic semiconductor layer 214 away from the initial substrate 230, wherein the type of doping element in the initial first doping conductive layer 255 is different from the type of doping element in the second doping conductive layer 215. After forming the second doping conductive layer 215, it may further include forming a transparent conductive layer 207 covering the surface of the second doping conductive layer 215 away from the intrinsic semiconductor layer 214.

[0179] In addition, in other embodiments of this application, the priority order of the intrinsic semiconductor layer 214 and the initial first dielectric layer 254 is not limited. Furthermore, the initial substrate 230, initial first surface 240, initial second surface 250, initial electrode region 291, initial transition region 292, initial non-electrode region 293, initial first dielectric layer 254, and initial first doping conductive layer 255 in Figure 17 are all similar to the corresponding configurations in the embodiments described above, and therefore their explanation is omitted here.

[0180] The following describes steps S12 to S14 in detail, using the formation of an IBC cell as an example.

[0181] In some embodiments, as shown in Figures 18 to 20, the initial electrode region 391 includes an initial positive electrode region 351 and an initial negative electrode region 361; as shown in Figure 11, the formed first dielectric layer 304 includes a first sub-dielectric layer 314 and a second sub-dielectric layer 324, where the first sub-dielectric layer 314 is located in the positive electrode region 311 and the second sub-dielectric layer 324 is located in the negative electrode region 321; the formed first doping conductive layer 305 includes a first sub-doping conductive layer 315 and a second sub-doping conductive layer 325, where the first sub-doping conductive layer 315 is located on the side of the first sub-dielectric layer 314 closer to the positive electrode region 311 and the second sub-doping conductive layer 325 is located on the side of the second sub-dielectric layer 324 closer to the negative electrode region 321; and the type of doping element in the first sub-doping conductive layer 315 is different from the type of doping element in the second sub-doping conductive layer 325.

[0182] Note that the initial substrate 330, initial first surface 340, initial second surface 350, initial electrode region 391, initial transition region 392, and initial non-electrode region 393 in Figures 18 to 20 are all similar to the corresponding structures in the embodiments described above, so their explanation is omitted here.

[0183] The following describes in detail the formation steps of the first sub-dielectric layer 314 and the second sub-dielectric layer 324.

[0184] In some embodiments, as shown in Figure 18, the step of forming an initial first dielectric layer 354 includes forming an initial first sub-dielectric layer 334 to cover an initial first surface 340, and the step of forming an initial first doping conductive layer 355 includes forming an initial first sub-doping conductive layer 335 to cover the surface of the initial first dielectric layer 354 on the side away from the initial substrate 330.

[0185] As shown in Figures 18 and 19, the step of employing a laser process involves removing the initial first subdielectric layer 334 and initial first subdoping conductive layer 335 located in the initial negative electrode region 361, initial transition region 392, and initial non-electrode region 393 in the first laser process, making the remaining initial first subdielectric layer 334 located in the initial positive electrode region 351 the first subdielectric layer 314, and making the remaining initial first subdoping conductive layer 335 located in the initial positive electrode region 351 the first subdoping conductive layer 315.

[0186] In some embodiments, as shown in Figure 20, the step of forming a second subdielectric layer 324 (see Figure 11) and a second subdoping conductive layer 325 (see Figure 11) after forming a first subdielectric layer 314 and a first subdoping conductive layer 315 may further include forming a first mask layer 308, where the first mask layer 308 is located on the side of the first subdoping conductive layer 315 away from the initial substrate 330.

[0187] As shown in Figure 20, the step of forming the initial first dielectric layer 354 includes forming an initial second sub-dielectric layer 344 that covers the initial first surface 340 and the first mask layer 308, and the step of forming the initial first doping conductive layer 355 further includes forming an initial second sub-doping conductive layer 345 that covers the surface of the initial second sub-dielectric layer 344 that is away from the initial substrate 330.

[0188] As shown in Figures 20 and 11, the step employing the laser process involves removing the initial second subdielectric layer 344 and initial second subdoping conductive layer 345 located in the initial positive electrode region 351, initial transition region 392, and initial non-electrode region 393 in the second laser process, making the remaining initial second subdielectric layer 344 located in the initial negative electrode region 361 the second subdielectric layer 324, and making the remaining initial second subdoping conductive layer 345 located in the initial negative electrode region 361 the second subdoping conductive layer 325.

[0189] As shown in Figures 20 and 11, the first mask layer 308 is removed.

[0190] In addition, the steps for forming the IBC cell differ from the steps for forming the initial first dielectric layer 354 and the initial first doping conductive layer 355 in the double-sided TOPCON cell and HJT cell of the above-described embodiment. In the steps for forming the IBC cell, the step for forming the initial first dielectric layer 354 includes two separate substeps, namely the step for forming the initial first subdivision layer 334 and the step for forming the initial second subdivision layer 344, and the step for forming the initial first doping conductive layer 355 includes two separate substeps, namely the step for forming the initial first subdoping conductive layer 335 and the step for forming the initial second subdoping conductive layer 345. The initial positive electrode region 351 and initial negative electrode region 361, which have undergone the first and second laser processes, become the positive electrode region 311 and the negative electrode region 321, respectively, and electrode region 301 becomes either the positive electrode region 311 or the negative electrode region 321. The initial transition region 392 and initial non-electrode region 393, which have undergone the first and second laser processes, become the transition region 302 and the non-electrode region 303, respectively.

[0191] As described above, in another embodiment of the present application, an initial first dielectric layer 154 and an initial first doping conductive layer 155 are formed over the entire surface, and then a transition region 102 with a first surface structure 112 is formed by laser processing, while the stacked first dielectric layer 104 and first doping conductive layer 105 are formed only in the electrode region 101. This improves the serious carrier recombination problem in the electrode region 101 through the passivation effect of the first dielectric layer 104 and first doping conductive layer 105 on the electrode region 101. On the other hand, the first dielectric layer 104 and first doping conductive layer 105 prevent the absorption of incident light irradiated onto the first surface 110 by the non-electrode region 103 and the transition region 102 from decreasing. Furthermore, the first surface structure 112 contributes to increasing the absorption rate of the first surface 110 with respect to incident light.

[0192] Another embodiment of the present application further provides a photovoltaic module comprising multiple solar cells provided in any of the embodiments described above, and used to convert the light energy received by the photovoltaic module into electrical energy. Figure 21 shows the structure of the photovoltaic module provided in another embodiment of the present application. For parts that are the same as or corresponding to the embodiments described above, the corresponding descriptions in the embodiments described above can be referred to. The following descriptions are omitted.

[0193] As shown in Figure 21, the photovoltaic module includes a cell string formed by connecting multiple solar cells 40 of any of the embodiments described above or by connecting multiple solar cells 40 formed by any of the manufacturing methods of any of the embodiments described above, a sealing adhesive film 41 for covering the surface of the cell string, and a cover plate 42 for covering the surface of the sealing adhesive film 41 away from the cell string. The solar cells 40 are electrically connected in whole or in multiple divisions to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel.

[0194] In some embodiments, multiple cell strings may be electrically connected by conduction bands 402. Figure 21 shows only the positional relationship between one type of solar cell, i.e., the arrangement direction of electrodes with the same polarity of the battery cells is the same, or the electrodes with the positive polarity of each battery cell are arranged on the same side, and the conduction bands are connected to the different sides of two adjacent battery cells, respectively. In some embodiments, the battery cells may have electrodes with different polarities facing the same side, i.e., the electrodes of multiple adjacent battery cells are arranged in the order of first polarity, second polarity, first polarity, respectively, and the conduction bands connect two adjacent battery cells on the same side.

[0195] In some embodiments, there is no spacing between the battery cells; that is, the battery cells overlap each other.

[0196] In some embodiments, the sealing adhesive film 41 includes a first sealing layer and a second sealing layer, wherein the first sealing layer covers either the front or back surface of the solar cell 40, and the second sealing layer covers the other front or back surface of the solar cell 40. Specifically, at least one of the first or second sealing layer may be an organic sealing adhesive film such as a polyvinyl butyral (PVB) adhesive film, an ethylene vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (POE) adhesive film, or a polyethylene terephthalate (PET) adhesive film.

[0197] In some cases, before lamination, there is a boundary between the first sealing layer and the second sealing layer, and after lamination, when the photovoltaic module is formed, the concepts of the first sealing layer and the second sealing layer no longer exist, that is, the first sealing layer and the second sealing layer are integrated to form a sealing adhesive film 41.

[0198] In some embodiments, the cover plate 42 may be a light-transmitting cover plate such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 42 facing the sealing adhesive film 41 may be an uneven surface, thereby increasing the utilization rate of incident light rays. The cover plate 42 comprises a first cover plate and a second cover plate, with the first cover plate facing the first sealing layer and the second cover plate facing the second sealing layer.

[0199] Those skilled in the art will understand that while the embodiments described above are specific examples of realizing the present disclosure, various modifications in form and detail are possible in practical use without departing from the spirit and scope of the embodiments of the present disclosure. Since any person skilled in the art can make changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure, the scope of protection of the embodiments of the present disclosure should be limited to the scope defined in the claims.

Claims

1. circuit board and A first dielectric layer located in the electrode region, The first dielectric layer includes a first doping conductive layer located on the side away from the electrode region of the first dielectric layer, The substrate comprises a first surface and a second surface that are positioned opposite each other, and the first surface includes electrode regions and non-electrode regions that are alternately positioned with a gap between them, and a transition region located between the electrode region and the non-electrode region. The first dielectric layer and the first doping conductive layer are formed only in the electrode region. The transition region comprises a first surface structure, the first surface structure includes a plurality of prismatic structures inclined toward the electrode region, the plurality of prismatic structures are sequentially arranged along at least a first direction, and the first direction is the direction of extension of the transition region. The prism structure includes a first prism structure and a second prism structure, wherein, along the inclination direction of the prism structure, the first length of the first prism structure is greater than the second length of the second prism structure, and at least a portion of the second prism structure is located on the side of the first prism structure away from the electrode region. The first surface structure further includes a first pyramidal structure, wherein at least a portion of the first pyramidal structure is located in a portion of the transition region close to the non-electrode region, and at least a portion of the prismatic structure is located in a portion of the transition region close to the electrode region. A solar cell characterized by the following features.

2. Multiple second prism structures are located on the side of the same first prism structure away from the electrode region, or multiple second prism structures are sequentially arranged along a direction away from the side of the first prism structure. The solar cell according to feature 1.

3. The first surface structure further comprises a plurality of micro-protrusion structures, wherein each micro-protrusion structure includes at least one of a second pyramidal structure or a triangular plate-like structure. The solar cell according to feature 1.

4. A second dielectric layer covering the aforementioned second surface, The present invention further includes a second doping conductive layer covering the surface of the second dielectric layer on the side away from the substrate, The type of doping element in the first doping conductive layer is different from the type of doping element in the second doping conductive layer. The solar cell according to feature 1.

5. The surface of the first doping conductive layer located in the electrode region comprises a second surface structure, the second surface structure comprising a plurality of third pyramidal structures, and the non-electrode region comprises a third surface structure, the third surface structure comprising a plurality of fourth pyramidal structures. The solar cell according to feature 4.

6. An intrinsic semiconductor layer covering the second surface, A second doping conductive layer covers the surface of the intrinsic semiconductor layer on the side away from the substrate, The present invention further includes a transparent conductive layer covering the surface of the second doped conductive layer away from the intrinsic semiconductor layer, The type of doping element in the first doping conductive layer is different from the type of doping element in the second doping conductive layer. The solar cell according to feature 1.

7. The electrode region has a first upper surface, and the non-electrode region has a second upper surface, with respect to the second surface, the first upper surface is higher than the second upper surface, and the height difference between the first upper surface and the second upper surface is 0.5 μm to 10 μm. The solar cell according to feature 1.

8. A cell string comprising a plurality of solar cells according to any one of claims 1 to 7, A sealing adhesive film for covering the surface of the cell string, Includes a cover plate for covering the surface of the sealing adhesive film away from the cell string, A photovoltaic module characterized by the following features.

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