Solar cells and photovoltaic modules

Abstract

This application relates to the photovoltaic field, providing a solar cell and a photovoltaic module. The solar cell includes: a substrate, the surface of which has a first region and a second region arranged at intervals, at least one of the first regions comprising a first part and a second part; a doped layer located within the substrate adjacent to the surface of the first part, the doping concentration of the doped layer being greater than the doping concentration of the substrate; a conductive layer located on the surface of the first region; a passivation layer located on the surfaces of the conductive layer and the second region; and a plurality of electrodes arranged at intervals along a first direction, the electrodes extending along a second direction, each electrode facing the second part, the electrodes being disposed on the side of the conductive layer away from the substrate and electrically connected to the conductive layer. The solar cell and photovoltaic module provided by this application can at least improve the photoelectric conversion efficiency.

Description

Technical Field

[0001] This application relates to the photovoltaic field, and in particular to a solar cell and a photovoltaic module. Background Technology

[0002] Factors affecting the performance of solar cells (such as photoelectric conversion efficiency) include optical losses and electrical losses. Optical losses include reflection losses from the front surface of the cell, shading losses from the contact grid lines, and non-absorption losses in the long wavelength range. Electrical losses include photogenerated carrier recombination on the semiconductor surface and within the cell, contact resistance between the semiconductor and metal grid lines, and contact resistance between the metal and semiconductor.

[0003] To reduce electrical and optical losses in solar cells, a polishing process is generally required on the back side of the cell. Back-side polishing primarily utilizes wet chemical methods to polish the boron-doped pyramidal textured surface structure on the back side, increasing internal light reflection, reducing the carrier surface recombination rate, and improving the cell's photoelectric conversion efficiency. In the back-side polishing process, the morphology of the polished back surface of crystalline silicon cells is beneficial for back reflection of long-wavelength light and the uniformity of subsequent back-side film formation, playing a crucial role in improving solar cell efficiency. While back-side polishing can optimize solar cell performance, many factors still influence the performance of this type of solar cell; therefore, developing high-efficiency passivated contact solar cells is of great significance. Summary of the Invention

[0004] This application provides a solar cell and a photovoltaic module, which at least helps to improve the photoelectric conversion efficiency of the solar cell.

[0005] According to some embodiments of this application, one aspect of this application provides a solar cell, comprising: a substrate, the surface of which has a first region and a second region arranged at intervals, at least one of the first regions comprising: a first part and a second part; a doped layer, the doped layer being located within the substrate adjacent to the surface of the first part, the doping concentration of the doped layer being greater than the doping concentration of the substrate; a conductive layer, the conductive layer being located on the surface of the first region; a passivation layer, the passivation layer being located on the surface of the conductive layer and the second region; and a plurality of electrodes arranged at intervals along a first direction, the electrodes extending along a second direction, each of the electrodes being directly opposite the second part, the electrodes being disposed on the side of the conductive layer away from the substrate, and electrically connected to the conductive layer.

[0006] In some embodiments, the conductivity type of the conductive layer is the same as that of the substrate; the solar cell further includes a tunneling dielectric layer located between the substrate and the conductive layer, and between the doped layer and the conductive layer.

[0007] In some embodiments, the tunneling dielectric layer has a heavily doped portion that is directly opposite the first portion.

[0008] In some embodiments, the doping concentration of the heavily doped portion is less than or equal to the doping concentration of the doped layer.

[0009] In some embodiments, the substrate is doped with either an N-type dopant or a P-type dopant, and the conductive layer is doped with either an N-type dopant or a P-type dopant.

[0010] In some embodiments, the material of the conductive layer is the same as the material of the substrate.

[0011] In some embodiments, the doping concentration of the conductive layer is less than the doping concentration of the doped layer.

[0012] In some embodiments, the doping concentration of the doped layer is 1E. 20 ~5E 21 cm -3 .

[0013] In some embodiments, the first region includes two first portions, with the second portion located between adjacent first portions.

[0014] In some embodiments, the widths of the two first portions are equal along the first direction.

[0015] In some embodiments, along the first direction, the size of the first spacing between the side of the doped layer facing the electrode and the side of the adjacent electrode facing the doped layer is proportional to the width of the contact surface between the electrode and the conductive layer.

[0016] In some embodiments, the first spacing is less than or equal to 1 / 10 of the width of the contact surface between the electrode and the conductive layer.

[0017] In some embodiments, along the first direction, the difference between the width of the conductive layer and the width of the contact surface between the conductive layer and the electrode is a preset value; the ratio of the width of the first part to the preset value ranges from 0.1 to 0.9.

[0018] In some embodiments, the width of the first part ranges from 20 μm to 500 μm.

[0019] In some embodiments, the substrate includes a first surface and a second surface facing each other, and the doped layer is located within the first surface and / or the second surface.

[0020] In some embodiments, along a direction perpendicular to the substrate surface, the top surface of the second region away from the substrate is lower than the top surface of the first region.

[0021] In some embodiments, the height difference between the top surface of the first region and the top surface of the second region ranges from 1 to 20 μm.

[0022] In some embodiments, the first region has a first texture structure, the first texture structure including at least one first protrusion structure; the second region has a second texture structure, the second texture structure including at least one second protrusion structure; the one-dimensional dimension of the top surface of the first protrusion structure is smaller than the one-dimensional dimension of the top surface of the second protrusion structure; or, per unit area, the number of the first protrusion structures is greater than or equal to the number of the second protrusion structures.

[0023] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: a battery string, the battery string being formed by connecting a plurality of solar cells as described in any of the above embodiments; an encapsulation layer for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulation layer away from the battery string.

[0024] The technical solution provided in this application has at least the following advantages:

[0025] In the technical solution provided by this application embodiment, by setting a doped layer in the first part, and the doping concentration of the doped layer is higher than that of the substrate, compared with setting a doped layer in the entire area aligned with the electrode (i.e., the area directly opposite the electrode also has a doped layer), the saturation current density in the second part is reduced, thereby increasing the open-circuit voltage. The high concentration of the doped layer can enhance the ability to collect current from the substrate, thereby offsetting the problem of poor current transmission caused by path growth. In addition, this application embodiment does not set a doped part in the second part region, but sets a doped part in the first part, which can avoid the problem that the bandgap of the substrate may shrink or even the open-circuit voltage of the solar cell may decrease when the concentration of doped elements below the electrode is too high, effectively avoiding the phenomenon of electric field decay. The low doping concentration in the electrode region aligned with the second part can avoid the high doping effect (such as recombination current caused by tunneling effect) caused by excessive doping concentration of the conductive layer or the doped layer. Attached Figure Description

[0026] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a first partial cross-sectional structure of a solar cell provided in some embodiments of this application;

[0028] Figure 2 This is a first example of a first region in a solar cell provided in some embodiments of this application;

[0029] Figure 3 This is a second example of the first region in a solar cell provided in some embodiments of this application;

[0030] Figure 4 This application provides schematic diagrams of carrier transport in solar cells according to some embodiments;

[0031] Figure 5 This is a schematic diagram of a second partial cross-sectional structure of a solar cell provided in some embodiments of this application;

[0032] Figure 6 This is a schematic diagram of a third partial cross-sectional structure of a solar cell provided in some embodiments of this application;

[0033] Figure 7 This is a schematic diagram of a fourth partial cross-sectional structure of a solar cell provided in some embodiments of this application;

[0034] Figure 8 This is a schematic diagram of a first structure of the first texture structure in a solar cell provided in some embodiments of this application;

[0035] Figure 9 This is a schematic diagram of a second structure of the first textured structure in a solar cell provided in some embodiments of this application;

[0036] Figure 10 This is a schematic diagram of a first structure of the second texture structure in a solar cell provided in some embodiments of this application;

[0037] Figure 11 This is a schematic diagram of a second structure of the second texture structure in a solar cell provided in some embodiments of this application;

[0038] Figure 12 Scanning electron microscope (SEM) images of the first surface of a solar cell provided in some embodiments of this application;

[0039] Figure 13 A fifth partial cross-sectional structural schematic diagram of a solar cell provided in some embodiments of this application;

[0040] Figure 14 This application provides a third example of the first region in a solar cell according to some embodiments;

[0041] Figure 15 A fourth example of the first region in a solar cell provided in some embodiments of this application;

[0042] Figure 16 A sixth partial cross-sectional structural schematic diagram of a solar cell provided in some embodiments of this application;

[0043] Figure 17 A seventh partial cross-sectional structural schematic diagram of a solar cell provided in some embodiments of this application;

[0044] Figure 18 This is a schematic diagram of a photovoltaic module provided in some embodiments of this application. Detailed Implementation

[0045] As can be seen from the background technology, the photoelectric conversion efficiency of solar cells in related technologies is poor.

[0046] Analysis revealed that one reason for the poor photoelectric conversion efficiency is that, to avoid misalignment between the electrodes and the conductive layer, conventional batteries typically set the width of the conductive layer to be larger than the width of the electrode, making the area in contact with the electrode a doped region and reducing contact resistance. However, on the side of the metal electrode close to the substrate, charge carriers or current can be directly transported longitudinally from the substrate side to the metal electrode side, resulting in smoother current transmission. But on the left and right sides of the metal electrode, in the areas covered by the conductive layer, the current needs to be transported laterally through the conductive layer to the metal electrode, increasing the path length and causing poor current transmission.

[0047] This application provides a solar cell where a doped layer is located in the first part, and the doping concentration of the doped layer is higher than that of the substrate. Compared to having a doped layer in the entire area aligned with the electrode (i.e., the area directly opposite the electrode also has a doped layer), this reduces the saturation current density in the second part, thereby increasing the open-circuit voltage. The high concentration of the doped layer enhances the ability to collect current from the substrate, thus offsetting the problem of poor current transmission caused by path growth. Furthermore, this application does not have a doped portion in the second part; instead, it has a doped portion in the first part. This avoids the problem of excessive doping concentration below the electrode, which could lead to a contraction of the substrate's bandgap and even a decrease in the open-circuit voltage of the solar cell, effectively preventing electric field degradation. The lower doping concentration in the electrode area aligned with the second part avoids the high doping effect caused by excessive doping concentration in the conductive layer or the doped layer itself.

[0048] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0049] Figure 1 This is a schematic diagram of a first partial cross-sectional structure of a solar cell provided in some embodiments of this application; Figure 2 This is a first example of a first region in a solar cell provided in some embodiments of this application; Figure 3 This is a second example of the first region in a solar cell provided in some embodiments of this application; Figure 4 This is a schematic diagram of carrier transport in a solar cell provided in some embodiments of this application.

[0050] According to some embodiments of this application, reference is made to Figures 1 to 4 One embodiment of this application provides a solar cell, including: a substrate 100, the surface of which has a first region 110 and a second region 120 arranged at intervals, at least one first region 110 including: a first part 111 and a second part 112; a doped layer 103 located within the substrate 100 adjacent to the surface of the first part 111, the doping concentration of the doped layer 103 being greater than the doping concentration of the substrate 100; a conductive layer 104 located on the surface of the first region 110; a passivation layer 105 located on the surfaces of the conductive layer 104 and the second region 120; and a plurality of electrodes 141 arranged at intervals along a first direction X, the electrodes 141 extending along a second direction, each electrode 141 facing the second part 112, the electrodes 141 being disposed on the side of the conductive layer 104 away from the substrate 100 and electrically connected to the conductive layer 104.

[0051] The substrate 100 is a region that absorbs incident photons to generate photogenerated carriers. In some embodiments, the substrate 100 is a silicon substrate, which may include one or more of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In some embodiments, the material of the substrate 100 may also be silicon carbide, organic materials, or multi-component compounds. Multi-component compounds may include, but are not limited to, materials such as perovskite, gallium arsenide, cadmium telluride, and copper indium selenide. Exemplarily, in this application, the substrate 100 is a monocrystalline silicon substrate.

[0052] In some embodiments, the front side of the substrate 100 is a light-receiving surface that absorbs incident light, and the back side of the substrate 100 is a backlighting surface, which is disposed opposite to the light-receiving surface. The substrate 100 contains doped elements, which are either N-type or P-type. N-type elements can be group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As), while P-type elements can be group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In). For example, when the substrate 100 is a P-type substrate, its internal doped element type is P-type. As another example, when the substrate 100 is an N-type substrate, its internal doped element type is N-type.

[0053] In some embodiments, the substrate 100 includes a first surface 101 (e.g., a backlight surface) and a second surface 102 (e.g., a light-receiving surface) facing each other. Taking a doped layer 103 located within the first surface 101 as an example, the second surface 102 of the substrate 100 has an emitter 108, which has a different doping element type than the substrate 100. Furthermore, the surface of the emitter 108 may have a textured structure to reduce the reflectivity of the second surface 102 of the substrate 100 to incident light, thereby maximizing light absorption and utilization.

[0054] In some embodiments, the position of the first region 110 corresponds to the position of the orthographic projection of the electrode 141 onto the substrate 100, and the area of ​​the first region 110 is greater than or equal to the area of ​​the electrode 141 to ensure alignment between the electrode 141 and the first region 110. The conductive layer 104 on the first region 110 can be a heavily doped region, meaning that due to ion diffusion, the doping concentration of the substrate 100 in the first region 110 can be greater than the doping concentration of the substrate 100 in the second region 120. Thus, the region directly opposite the electrode 141 is a heavily doped region, reducing the contact resistance between the electrode 141 and the conductive layer 104. The doped ions can act as charge carriers, thereby increasing the number of charge carriers and their mobility, which is beneficial for improving the photoelectric conversion efficiency of the solar cell. The substrate 100 where the second region 120 is located is a lightly doped region, reducing the recombination rate on the surface of the substrate 100 and improving the photoelectric conversion efficiency of the cell.

[0055] Understandably, the width of the substrate 100 in the first region 110 should not be too large. An excessively large width of the substrate 100 in the first region 110 may affect the integrity and uniformity of the film on the surface of the substrate 100 in the second region 120, reduce internal light reflection, and thus be detrimental to improving the surface recombination rate of charge carriers and the photoelectric conversion efficiency of the solar cell.

[0056] In some embodiments, along the first direction X, the width of the first region 110 is 1 to 3 times the width of the contact surface between the electrode 141 and the conductive layer 104. By controlling the range of the width of the first region 110, it is ensured that the surface in contact with the electrode 141 is a highly doped conductive layer 104, reducing the contact resistance between the electrode 141 and the conductive layer 104 and improving the conductivity transport rate of the electrode 141. The film layer on the second region 120 is intact, reducing recombination centers and improving the internal reflection of light and the passivation effect of the film layer. The width of the substrate 100 of the first region 110 is 20 μm to 50 μm; the width of the first region 110 can also be 20 μm to 40 μm, 30 μm to 50 μm, 20 μm to 47 μm, or 25 μm to 40 μm. For example, the width of the first region 110 can be 20.3 μm, 33 μm, 35 μm, 45 μm, or 49 μm.

[0057] In some embodiments, such as Figure 1 As shown, the planes of the first zone 110 and the second zone 120 are polished surfaces, meaning they are formed into a complete plane through solution polishing or laser polishing. Here, "plane" refers to a plane with low roughness, or a roughness less than or equal to 0.4. It should be noted that roughness can be surface roughness or roughness Ra. Surface roughness refers to the small spacing (less than 1 mm) and minute peak-valley unevenness of a machined surface. Surface roughness belongs to microscopic geometric shape errors. Roughness Ra refers to the arithmetic mean of the absolute values ​​of the Z-axis deviations relative to the mean line over a sampling length. Roughness can be measured using methods such as comparison, optical sectioning, interferometry, and stylus tracing.

[0058] In some embodiments, to ensure that the areas contacted by the electrode 141 are all heavily doped regions, the width of the first region 110 is typically set to be greater than the width of the electrode 141. Thus, the first region 110 may include a first part 111 and a second part 112. The first part 111 is the area where the electrode is not directly opposite, but it has a tunneling dielectric layer 107 and a conductive layer 104. The second part 112 is the area where the electrode 141 is directly opposite. It is worth noting that "directly opposite" here means that the orthographic projection of the electrode 141 onto the substrate 100 substantially coincides with or deviates from the outline or area of ​​the second part 112 by less than 20%.

[0059] In some embodiments, along the first direction X, the ratio of the range of the first part 111 to the range of the second part 112 can be set according to the actual arrangement of the solar cell. The ratio of the range of the first part 111 to the range of the second part 112 is used to ensure that the width of the electrode 141 is set appropriately, the current collection capability is strong and the electrical loss is small; it is also used to ensure that the range of the second region 120 is appropriate, the integrity of the film layer deposited on the conductive layer 104 and the second region 120 is good, and it has a high passivation effect.

[0060] In some embodiments, along the first direction X, the width of the first portion 111 ranges from 20 μm to 500 μm. This width range can serve as a lateral deviation value from the width of a conventional electrode. This range ensures that there can be some deviation during electrode alignment, and that the areas directly opposite the electrode 141 can all be highly doped regions, reducing the contact resistance of the electrode 141. This range ensures that the overall width or proportion of the first region 110 is not too large, the area of ​​carrier recombination centers on the substrate surface is not too large, and the integrity and density of the film layer formed on the substrate 100 surface are good, improving the passivation effect of the solar cell. Finally, this range ensures that the width of the doped layer 103 located thereon can be set to be larger, the area of ​​the transport channel is larger, and the carrier transport rate is increased to improve cell efficiency.

[0061] In some embodiments, along the first direction X, the width of the first portion 111 ranges from 20 μm to 400 μm, 20 μm to 250 μm, or 20 μm to 100 μm. This range shortens the proportion of the first region 110 and reduces optical loss. The high-concentration doped layer 103 located in the first portion 111 can enhance the ability to collect current from the substrate 100, thereby offsetting the problem of poor current transmission caused by path growth. The width of the first portion 111 can be 20 μm, 48 μm, 69 μm, 98 μm, 138 μm, or 209 μm.

[0062] In some embodiments, along the first direction X, the size of the first spacing L between the side of the doped layer 103 facing the electrode 141 and the side of the adjacent electrode 141 facing the doped layer 103 is proportional to the width of the contact surface between the electrode 141 and the conductive layer 104. That is, the wider the contact surface between the electrode 141 and the conductive layer 104, the larger the area of ​​the eddies generated by the electrode 141 absorbing current within the conductive layer 104. A higher doping concentration in the doped layer 103, and a larger overlap between the doped layer 103 and the eddy region, can affect the open-circuit voltage of the solar cell, leading to electric field degradation. Conversely, the first spacing L is proportional to the width of the contact surface between the electrode 141 and the conductive layer 104. When the width of the contact surface is larger, the first spacing L is also larger, reducing the overlap or overlapping area between the eddies and the doped layer 103 to ensure the open-circuit voltage remains within a larger range.

[0063] In some embodiments, the first spacing L is less than or equal to 1 / 10 of the width of the contact surface between the electrode 141 and the conductive layer 104. In this way, the area of ​​the doped layer 103 located in the first part 111 can be ensured to be appropriate within a limited first region, that is, the area of ​​the carrier transport path. The larger the area of ​​the carrier transport path, the greater the photoelectric conversion efficiency of the solar cell.

[0064] In some embodiments, along the first direction X, the difference between the width of the conductive layer 104 and the width of the contact surface between the conductive layer 104 and the electrode 141 is a preset value; the ratio of the width of the first portion 111 to the preset value ranges from 0.1 to 0.9. Along the first direction X, the electrode 141 is flush with the side surface of the conductive layer 104 to minimize material waste in the conductive layer 104. However, in actual operation, such as... Figure 3 As shown, the electrode 141 is not completely flush with the side of the conductive layer 104. The electrode 141 is slightly offset from the central axis of the conductive layer 104, resulting in a region that does not belong to either the first part 111 or the second part 112. The ratio of the width of the first part 111 to the preset value ensures the alignment of the electrode 141 and the conductive layer 104, preventing any misalignment.

[0065] In some embodiments, the doping concentration of the doped layer 103 is 1E. 20 ~5E 21 cm -3 The doping concentration of doped layer 103 can also be 3E. 20 ~5E 21 cm -3 1E 20 ~1E 21 cm -3 8E 20 ~5E 21 cm -3 Or 3E 20 ~3E 21 cm -3 The doping concentration of the doped layer 103 can be 1.5E. 20 cm -3 3.8E 20 cm -3 8.3E 21 cm -3 3E 21 cm -3 Or 5E 21 cm -3This concentration range ensures that the doping concentration of the doped layer 103 is greater than both the doping concentration of the substrate 100 and the doping concentration of the conductive layer 104, preventing the substrate bandgap from shrinking due to excessive doping concentration of the substrate 100 and ensuring the stability of the open-circuit voltage. When the doping concentration of the doped layer 103 is greater than that of the substrate 100, a high-low junction is formed between the doped layer 103 and the substrate 100, thereby creating a built-in electric field between them. A positive space charge forms on the surface of the more doped layer 103, while a negative space charge forms on the surface of the less doped substrate 100. This facilitates the drift of majority carriers from the substrate 100 to the more doped layer 103, which is beneficial for increasing the battery's output current. Simultaneously, due to the presence of the built-in electric field, a potential barrier exists between the substrate 100 and the doped layer 103, preventing the drift of more doped majority carriers to the less doped substrate 100.

[0066] In some embodiments, when the doping concentration of the doped layer 103 is greater than that of the conductive layer 104, the dopants in the doped layer 103 migrate to the tunneling dielectric layer 107 and the conductive layer 104, establishing a carrier transport channel and increasing the carrier transport rate. When the doping concentration of the doped layer 103 is 1E... 20 ~5E 21 cm -3 At that time, the doping concentration range of conductive layer 104 is 5E. 19 ~1E 21 cm -3 For example, the doping concentration of doped layer 103 is 3E. 20 ~5E 21 cm -3 At that time, the doping concentration range of conductive layer 104 is 8E. 19 ~8E 20 cm -3 The doping concentration of doped layer 103 is 1E. 20 ~2E 21 cm -3 At that time, the doping concentration range of conductive layer 104 is 5E. 19 ~4E 20 cm -3 .

[0067] In some embodiments, when the material of the doped layer 103 is the same as the material of the substrate 100, the doped layer 103 and the substrate 100 can be regarded as the same original substrate. The doped layer 103 is located in the region of the original substrate adjacent to the first surface 101. The fact that the material of the doped layer 103 is the same as the material of the substrate 100 can avoid the consumption of photogenerated carriers due to the conductivity of different materials. There are no interface state defects between the doped layer 103 and the substrate 100, which would lead to partial carrier recombination and reduce battery efficiency.

[0068] In some embodiments, the conductivity type of the conductive layer 104 is the same as that of the substrate 100. The solar cell further includes a tunneling dielectric layer 107, which is located between the substrate 100 and the conductive layer 104, and between the doped layer 103 and the conductive layer 104. The solar cell forms a passivated contact structure through the tunneling dielectric layer 107 and the conductive layer 104, thus the solar cell is a tunnel oxide passivated contact (TOPCon) solar cell, which may include a double-sided tunnel oxide passivated contact (both the first and second surfaces have a tunneling dielectric layer and a conductive layer) or a single-sided tunnel oxide passivated contact (either the first or second surface has a tunneling dielectric layer and a conductive layer). For example, the solar cell is a single-sided tunnel oxide passivated contact, and the back surface (first surface 101) of the solar cell has a tunnel oxide passivated layer.

[0069] In some embodiments, the material of the tunneling dielectric layer 107 may include, but is not limited to, dielectric materials with tunneling properties such as alumina, silicon oxide, silicon nitride, silicon oxynitride, intrinsic amorphous silicon, and intrinsic polycrystalline silicon. The thickness of the tunneling dielectric layer 107 may be 0.5 nm to 2.5 nm, optionally 0.5 nm to 2 nm, and preferably 0.5 nm to 1.2 nm. The material of the conductive layer 104 may be at least one of polycrystalline semiconductor, amorphous semiconductor, or microcrystalline semiconductor, preferably at least one of polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The thickness of the conductive layer 104 ranges from 40 nm to 150 nm, optionally 60 nm to 90 nm. This thickness range ensures minimal optical loss in the conductive layer 104 and good interface passivation of the tunneling dielectric layer 107, thereby improving battery efficiency. For example, in this embodiment, the material of the conductive layer 104 is polycrystalline silicon, and the thickness of the conductive layer 104 is 80 nm.

[0070] Figure 5 This is a schematic diagram of a second partial cross-sectional structure of a solar cell provided in some embodiments of this application.

[0071] like Figure 5 As shown, in some embodiments, the first region 110 further includes a doped portion 106 formed by the diffusion of the conductive layer 104 to the surface of the substrate 100. The doping concentration of the doped portion 106 is greater than that of the substrate 100, which is beneficial for improving carrier transport efficiency, open-circuit voltage, and current transmission efficiency, thereby improving the photoelectric conversion efficiency of the solar cell. The doping concentration of the doped portion 106 is 2E. 20 cm -3~2E 21 cm -3 The doping concentration of doped portion 106 can also be 2E. 20 ~1E 21 cm -3 5E 20 ~2E 21 cm -3 3.8E 20 ~1E 21 cm -3 Or 2E 20 ~9E 20 cm -3 The doping concentration of the doped portion 106 can be 2E. 20 cm -3 4.8E 20 cm -3 6.3E 20 cm -3 9.8E 20 cm -3 Or 2E 21 cm -3 .

[0072] In some embodiments, the doped portion 106 is also a diffusion layer, which can be formed by a separate diffusion process (direct doping on the surface of the doped portion 106), or by the doping element of the diffusion process during the formation of the conductive layer 104 or the doped layer 103 penetrating into the substrate to form a doped portion with a higher doping concentration than the substrate 100, or by a combination of both.

[0073] Figure 6 This is a schematic diagram of a third partial cross-sectional structure of a solar cell provided in some embodiments of this application.

[0074] like Figure 6 As shown, in some embodiments, the tunneling dielectric layer 107 has a heavily doped region 121, which is directly opposite the first region 111. The heavily doped region 121 is a region formed by the diffusion of the doped layer 103 into the tunneling dielectric layer 107. The doping concentration of the heavily doped region 121 is greater than the doping concentration of the tunneling dielectric layer 107 excluding the heavily doped region 121. This improves the transport efficiency of charge carriers from the substrate 100 to the doped layer 103, then to the heavily doped region 121, and finally to the electrode 141. This is beneficial for improving the open-circuit voltage and current transmission efficiency, thereby improving the photoelectric conversion efficiency of the solar cell. For example, if the doping element is phosphorus, the phosphorus content in the tunneling dielectric layer 107 increases. As phosphorus diffuses back into the tunneling dielectric layer 107, the ability of the tunneling dielectric layer 107 to block majority carriers decreases, thus enhancing the majority carrier current transmission capability.

[0075] Figure 7 This is a schematic diagram of a fourth partial cross-sectional structure of a solar cell provided in some embodiments of this application; Figure 8 This is a schematic diagram of a first structure of the first texture structure in a solar cell provided in some embodiments of this application; Figure 9 This is a schematic diagram of a second structure of the first textured structure in a solar cell provided in some embodiments of this application; Figure 10 This is a schematic diagram of a first structure of the second texture structure in a solar cell provided in some embodiments of this application; Figure 11 This is a schematic diagram of a second structure of the second texture structure in a solar cell provided in some embodiments of this application; Figure 12 Scanning electron microscope (SEM) images of the first surface of a solar cell provided in some embodiments of this application.

[0076] like Figures 7 to 12 As shown, in some embodiments, along a direction perpendicular to the surface of the substrate 100, the top surface of the second region 120, away from the substrate 100, is lower than the top surface of the first region 110. The height difference between the top surfaces of the first region 110 and the second region 120 is designed so that the first region 110 serves as the basis for aligning the electrode 141, and the sidewalls of the height difference can increase the reflective surface of the first surface 101, thereby improving the optical internal reflection effect on the back of the solar cell. Here, the top surface of the first region 110 refers to the bottom surface of the first textured structure or the surface of the first textured structure in contact with the substrate 100, and the top surface of the second region 120 refers to the bottom surface of the second textured structure or the surface of the second textured structure in contact with the substrate 100.

[0077] In some embodiments, the height difference h between the top surface of the first region 110 and the top surface of the second region 120 ranges from 1 μm to 20 μm. Preferably, the height difference h ranges from 1 μm to 10 μm, 1 μm to 15 μm, 5 μm to 20 μm, or 5 μm to 15 μm. Thus, the height difference h range can serve as a basis for optical identification of the alignment of the first region 110, the second region 120, and the electrode 141. Furthermore, the sidewalls of the height difference can increase the reflective surface of the first surface 101, thereby improving the optical internal reflection effect on the back of the solar cell. However, a large height difference can increase the overall thickness of the cell, which is detrimental to improving the integration density of the solar cell. Alternatively, if the polishing of the second region 120 is too excessive, the thickness of the substrate 100 of the solar cell may be too thin, potentially causing carriers to tunnel from the first surface 101 to the second surface 102.

[0078] In some embodiments, the second region 120 includes two first sub-regions 131 and a second sub-region 132 located between the first sub-regions 131. The extending direction of the first sub-regions 131 intersects the first direction X, and the extending direction of the second sub-region 132 is parallel to the first direction X. The first sub-regions 131 are located between the first region 110 and the second sub-region 132. That is, the second region 120 can be regarded as a groove or trench recessed towards the second surface of the substrate 100 with the surface of the first region 110 as a reference plane, including an inner wall surface (first sub-region 131) and a bottom (second sub-region 132). Thus, the increased first sub-regions 131 increase the surface area of ​​the substrate 100, resulting in a larger area of ​​the passivation film formed on the surface of the substrate 100 and a better passivation effect. Further, the angle α between the extending direction of the first sub-region 131 and the first direction X is an acute angle or an obtuse angle. That is, the surface of the first sub-region 131 is inclined relative to the surface of the second sub-region 132. The inclined surface or groove can promote the better density of the passivation layer 105 formed on the second region 120, improve the passivation effect, and the inclined surface increases the internal reflection of light, thereby improving the battery efficiency.

[0079] In some embodiments, the first region 110 has a first texture structure, which is a velvety structure. The sloping surface of the velvety structure can increase the internal reflection of incident light, so that the incident light is reflected multiple times in the velvety structure and finally absorbed by the substrate, thereby improving the photoelectric conversion efficiency. The first texture structure can be any morphological structure different from the flat surface, such as a texture structure composed of multiple grooves, a structure composed of multiple protrusions, or a texture structure composed of both grooves and protrusions.

[0080] In some embodiments, the first textured structure includes at least one first protrusion structure 123. Along a direction perpendicular to the first surface 101, the first thickness h1 of the top surface of the first protrusion structure 123 away from the first surface 101 and the bottom surface near the first surface 101 is greater than or equal to 2 μm. The height of the first protrusion structure 123 is relatively high. On the one hand, with a fixed bottom area (the area where the first protrusion structure 123 contacts the first surface 101 of the substrate 100), the increase in height can increase the slope area, and the contact area between the electrode 141 and the conductive layer 104 is also increased. The increase in slope area can also increase the internal reflectivity of incident light, reduce optical loss, and improve photoelectric conversion efficiency.

[0081] In some embodiments, the first protrusion structure 123 refers to a platform protrusion structure with a polygonal top surface, or it can be considered as a pyramid structure with a portion of its thickness removed from the top, thus forming a platform protrusion structure with a polygonal top surface. It is understood that the first protrusion structure 123 can be formed whether the direction of the removal from the top of the pyramid structure is parallel or not parallel to the substrate surface. The platform protrusion structure, compared to a conventional pyramid structure or a polished back surface, has a larger top surface area than the pyramid structure, which facilitates the deposition of subsequent film layers and improves the passivation effect. Compared to a polished surface, the platform protrusion structure, with its sloping surface, increases the internal reflectivity of light and reduces the contact resistance between the substrate and the electrode, thereby improving battery efficiency. The sides of the platform protrusion structure form an angle with the substrate surface, allowing incident light to be reflected from one platform protrusion structure to another. This results in a better anti-reflection effect on the textured surface formed by the platform protrusion structure, reducing light reflectivity and increasing the short-circuit current Isc, thereby improving the photoelectric conversion efficiency of the cell. The top surface of the platform protrusion structure is a polygonal plane, which facilitates the deposition of subsequent film layers, resulting in fewer defects in the formed film layers and improving the passivation effect of the solar cell. In some embodiments, the first protrusion structure 123 includes a platform-like protrusion structure or other protrusion structures with inclined surfaces and a top surface. The polygonal plane can be a quadrilateral plane, a pentagonal plane, or a plane of any shape, and can be a regular or irregular shape.

[0082] In some embodiments, the average one-dimensional dimension W1 of the top surface of the first protrusion structure 123 refers to the average value of the top surface one-dimensional dimensions of each of the first protrusion structures 123 within a randomly selected area of ​​the first region 110. Therefore, it can be understood that the average one-dimensional dimension W1 of the top surface of the first protrusion structure 123 refers to the range of average values ​​for a region, not the entire range of the top surface one-dimensional dimensions of all the first protrusion structures 123 within the first region 110, and the entire range of the top surface one-dimensional dimensions of all the first protrusion structures within the first region 110 is generally larger than the range of the average value. (For illustrative purposes only.) Figure 8 and Figure 9 The first protrusion structure 123 in each of the middle has the same shape, and its one-dimensional size is equal to the average one-dimensional size W1.

[0083] It is worth noting that one-dimensional dimension refers to, for example, Figure 12 As shown, this is the distance between two diagonals in the top surface pattern of the first protrusion structure 123. In some embodiments, the one-dimensional dimension can also be the distance between two sides of the top surface pattern.

[0084] In some embodiments, the average one-dimensional dimension W1 of the top surface of the first protrusion structure 123 ranges from 0.5 μm to 20 μm. Preferably, W1 ranges from 5 μm to 20 μm, 0.5 μm to 15 μm, 1 μm to 18 μm, or 10 μm to 20 μm. For example, W1 can be 1 μm, 3.8 μm, 7.3 μm, 10.6 μm, or 15 μm.

[0085] like Figure 9 As shown, in some embodiments, the surface of the first textured structure has a third textured structure, which includes at least one third protrusion 124 located on the surface of the first protrusion 123. The morphology of the third protrusion 124 can be a pyramid structure, a pyramid-like structure, a platform protrusion structure, or other protrusion structures with slopes. The third protrusion 124 can be prepared on the surface of the first textured structure using laser technology, increasing the composite center and roughness of the first textured structure, thereby increasing the contact surface between the conductive layer 104 and the electrode 141, reducing the contact resistance between the electrode 141 and the conductive layer 104, and improving battery efficiency.

[0086] In some embodiments, at least two third protrusions 124 are stacked on the surface of a first protrusion structure 123 to increase the contact area between the first region 110 and the electrode 141, and further increase the roughness of the first region 110 to improve battery efficiency. Furthermore, the average one-dimensional dimension W1 of the top surface of the first protrusion structure 123 is greater than the average one-dimensional dimension W3 of the top surface of the third protrusion structure 124.

[0087] In some embodiments, the height h3 between the top and bottom surfaces of the third protrusion structure 124 is less than or equal to 2 μm; the average one-dimensional dimension W3 of the top surface of the third protrusion structure 124 ranges from 0.01 μm to 5 μm, preferably, the average one-dimensional dimension W3 of the top surface of the third protrusion structure 124 is 0.01 μm to 3 μm, 0.1 μm to 5 μm, 0.1 μm to 4 μm, or 0.01 μm to 3 μm. For example, the average one-dimensional dimension W3 of the top surface of the third protrusion structure 124 is 0.02 μm, 0.13 μm, 0.59 μm, 1.3 μm, or 5 μm. The average one-dimensional dimension of the bottom surface of the third protrusion structure 124 ranges from 5μm to 60μm. Preferably, the average one-dimensional dimension of the bottom surface of the third protrusion structure 124 ranges from 5μm to 55μm, 10μm to 60μm, 30μm to 40μm, or 30μm to 60μm. For example, the average one-dimensional dimension of the bottom surface of the third protrusion structure 124 ranges from 5μm, 18μm, 31μm, 43μm, or 52μm.

[0088] In some embodiments, such as Figure 10 and Figure 11As shown, the second region 120 has a second texture structure, which includes at least one second protrusion structure 125. The average one-dimensional dimension W2 of the top surface of the second protrusion structure 125 ranges from 5μm to 50μm. Preferably, W2 ranges from 20μm to 50μm, 5μm to 40μm, 10μm to 40μm, or 30μm to 50μm. For example, W2 can be 6μm, 13.8μm, 27.6μm, 30.9μm, or 45μm.

[0089] The second protrusion structure 125 is designed in the same way or similarly to the first protrusion structure 123, that is, the second protrusion structure 125 is a platform protrusion structure with a polygonal top surface. In some embodiments, the second protrusion structure may also include a platform-like protrusion structure or other protrusion structures with slopes and a top surface.

[0090] In some embodiments, the definition of the average one-dimensional dimension W2 of the top surface of the second protrusion structure 125 is the same as or similar to the definition of the average one-dimensional dimension W1 of the top surface of the first protrusion structure 123, and will not be elaborated further here.

[0091] In some embodiments, the surface of the second protrusion structure 125 has a fourth texture structure, which includes at least one fourth protrusion structure 126 located on the surface of the second protrusion structure 125. The morphology of the fourth protrusion structure 126 can be a pyramid structure, a pyramid-like structure, a platform protrusion structure, or other protrusion structures with slopes. The fourth protrusion structure 126 can be prepared on the surface of the second texture structure using laser technology, increasing the roughness of the second texture structure and increasing the internal reflectivity of the second region 120 to improve battery efficiency.

[0092] In some embodiments, at least two fourth protrusions 126 are stacked on the surface of a second protrusion 125 to increase the internal reflectivity of the second region 120. The average one-dimensional dimension W2 of the top surface of the second protrusion 125 is greater than the average one-dimensional dimension of the top surface of the fourth protrusion 126.

[0093] In some embodiments, the height between the top and bottom surfaces of the fourth protrusion structure 126 is less than or equal to 2 μm; the average one-dimensional dimension of the top surface of the fourth protrusion structure 126 ranges from 0.01 μm to 5 μm, preferably, the average one-dimensional dimension of the top surface of the fourth protrusion structure 126 is 0.01 μm to 3 μm, 0.1 μm to 5 μm, 0.1 μm to 4 μm, or 0.01 μm to 3 μm. For example, the average one-dimensional dimension of the top surface of the fourth protrusion structure 126 is 0.02 μm, 0.13 μm, 0.59 μm, 1.3 μm, or 5 μm.

[0094] In some embodiments, along a direction perpendicular to the first surface 101, the first protrusion 123 is away from the first thickness h1 (reference) between the top and bottom surfaces of the substrate 100. Figure 8 The second thickness h2 between the top and bottom surfaces of the second protrusion 125, which is farther from the base 100, is greater than the second thickness h2 (reference). Figure 10 The roughness of the first texture structure in the first region 110 is greater than the roughness of the second texture structure in the second region 120. It is worth noting that the average one-dimensional dimension of the bottom surface of the first protrusion structure 123 in contact with the substrate 100 is equal to the average one-dimensional dimension of the bottom surface of the second protrusion structure 125 in contact with the substrate 100. The first protrusion structure 123 and the second protrusion structure 125 can be prepared from the same initial texture structure, and the polishing degree of the first protrusion structure 123 is weaker than that of the second protrusion structure 125.

[0095] In some embodiments, the top surface one-dimensional dimension of the first protrusion structure 123 is smaller than the top surface one-dimensional dimension of the second protrusion structure 125. The two are different in optical recognition, thereby enabling the self-alignment of the electrode 141 through the difference, avoiding the electrode 141 from shifting, and thus avoiding the shifting of the subsequent solder strip, thereby improving battery performance.

[0096] In some embodiments, the number of first protrusion structures 123 per unit area is greater than or equal to the number of second protrusion structures 125. Since the polishing degree of the second region 120 is greater than that of the first region 110, part of the initial texture structure located in the second region 120 is etched away. Therefore, the number of second protrusion structures 125 is less than the number of first protrusion structures 123.

[0097] Figure 13 A fifth partial cross-sectional structural schematic diagram of a solar cell provided in some embodiments of this application; Figure 14 This application provides a third example of the first region in a solar cell according to some embodiments; Figure 15 This is a fourth example of the first region in a solar cell provided in some embodiments of this application.

[0098] In some embodiments, reference Figures 13-15 The first region 110 includes two first portions 111, with a second portion 112 located between adjacent first portions 111. The electrode 141 is located in the central region of the first region 110 (the region where the axis lies). The electrode 141 and the conductive layer 104 can be perfectly aligned, avoiding electrical losses caused by electrode misalignment. Furthermore, the two first portions mean that two doped layers 103 can be disposed in the two first portions 111, establishing two carrier transport channels. This reduces the transport paths of carriers not located near the doped layer 103, reducing electrical losses and thus improving battery efficiency.

[0099] In some embodiments, the widths of the two first portions 111 are equal along the first direction X. On the one hand, the size of the doped layer 103 on the two first portions 111 can be set to be the same, thereby simplifying the process steps for preparing the doped layer 103; two carrier transport channels can be established in the substrate on both sides of the electrode 141, reducing the carrier transport path between the second region 120 and the second portion 112, reducing electrical losses, and thus improving battery efficiency.

[0100] It is understandable that the “equal” in the above statement “the widths of the two first parts are equal” refers to being substantially equal, which includes being completely equal as well as fluctuating within 20% (i.e., deviating).

[0101] In some embodiments, when the first surface 101 is a backlight surface, the passivation layer 105 can be regarded as a post-passivation layer. The passivation layer 105 can be a single-layer structure or a stacked structure, and the material of the passivation layer 105 can be one or more of the following materials: silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0102] In some embodiments, the passivation layer 105 includes at least one of an aluminum oxide layer, a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer. The solar cell also includes an antireflection layer 122 (see reference) stacked on the surface of the passivation layer 105. Figure 7 Antireflective layer 122 (reference) Figure 7 The materials used include silicon nitride or silicon oxynitride. The high refractive index of silicon nitride or silicon oxynitride reduces the reflection of incident light.

[0103] Electrode 141 extends along a second direction and serves as the grid line of a solar cell, used to collect and summarize the current from the solar cell. Electrode 141 may be formed by sintering a burn-through paste. The material of electrode 141 may be one or more of aluminum, silver, gold, nickel, molybdenum, or copper. In some cases, electrode 141 refers to fine grid lines or finger grid lines to distinguish it from main grid lines or busbars. Electrode 141 is either a back electrode or a bottom electrode. Electrode 141 is either a positive electrode or a negative electrode.

[0104] In some embodiments, the solar cell further includes: a first passivation layer 109, the first passivation layer 109 being located on the surface of the emitter 108 away from the substrate 100, and when the second surface 102 is the light-receiving surface, the first passivation layer 109 is regarded as the front passivation layer; a plurality of spaced first electrodes 142, the first electrodes 142 penetrating the first passivation layer 109 and contacting the emitter 108.

[0105] In some embodiments, the first passivation layer 109 may be a single-layer structure or a stacked structure, and the material of the first passivation layer 109 may be one or more of the following materials: silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0106] The first electrode 142 may be sintered from a burn-through slurry. The contact between the first electrode 142 and the emitter 108 may be localized or complete. The material of the first electrode 142 may be one or more of aluminum, silver, nickel, gold, molybdenum, or copper. In some embodiments, the first electrode 142 may be an upper electrode or a front electrode, or a positive electrode or a negative electrode. In some cases, the first electrode 142 refers to a fine grid line or finger grid line, to distinguish it from a main grid line or busbar.

[0107] Furthermore, the first direction X and the second direction can be perpendicular to each other, or they can have an angle of less than 90 degrees, such as 60 degrees, 45 degrees, 30 degrees, etc., as long as the first direction X and the second direction are not the same direction. For ease of explanation and understanding, this embodiment uses the example of the first direction X and the second direction being perpendicular. In specific applications, the angle between the first direction X and the second direction can be adjusted according to actual needs and application scenarios; this embodiment does not impose any limitations on this.

[0108] This application provides a solar cell. By setting a doped layer 103 in the first part 111 and having a higher doping concentration than the substrate 100, the saturation current density of the second part 112 is reduced compared to setting a doped layer in the entire area aligned with the electrode 141, i.e., the area directly opposite the electrode 141 also has a doped layer 103, thereby increasing the open-circuit voltage. The high concentration of the doped layer 103 can enhance the ability to collect current from the substrate 100, thereby offsetting the problem of poor current transmission caused by path growth.

[0109] Figure 16 A sixth partial cross-sectional structural schematic diagram of a solar cell provided in some embodiments of this application;

[0110] The above embodiments are described with the doped layer located within a first surface. Some embodiments of this application also provide a solar cell with the doped layer located within a second surface, which will be referred to below. Figure 16 The following detailed description will be provided, and the same components as those in the above embodiments will not be repeated here.

[0111] refer to Figure 16The solar cell includes: a substrate 200, the surface of which has a first region 210 and a second region 220 spaced apart, at least one first region 210 including: a first part 211 and a second part 212; a doped layer 203 located within the substrate 200 adjacent to the second surface 202 of the substrate 200, the doping concentration of the doped layer 203 being greater than the doping concentration of the substrate 200; a conductive layer 204 located on the surface of the first region 210; a passivation layer 205 located on the surfaces of the conductive layer 204 and the second region 220; and a plurality of electrodes 242 spaced apart along a first direction X, the electrodes 242 extending along a second direction, each electrode 242 facing the second part 212, the electrodes 242 being disposed on the side of the conductive layer 204 away from the substrate 200 and electrically connected to the conductive layer 204.

[0112] In some embodiments, the doped layer 203 is located within the second surface 202. As part of the emitter 208, the doped layer 203 reduces the saturation current density of the second part 212, thereby increasing the open-circuit voltage, compared to having a doped layer in the entire region aligned with the electrode 242, i.e., the region directly opposite the electrode 242 also has a doped layer 203. The high concentration of the doped layer 203 can enhance the ability to collect current from the substrate 200, thereby offsetting the problem of poor current transport caused by path growth.

[0113] In some embodiments, the conductive layer 204 is made of the same material as the substrate 200. The conductive layer 204 is located within the substrate 200 near the second surface 202. The conductive layer 204 is part of the emitter 208. The doping concentration of the conductive layer 204 is greater than that of the emitter 208, resulting in a heavily doped region aligned with the electrode 242, which reduces the contact resistance of the electrode 242. The lower doping concentration of the emitter 208 reduces the surface recombination rate of the substrate, thereby improving battery efficiency.

[0114] In some embodiments, the substrate 200 is doped with either an N-type or a P-type dopant, and the conductive layer 204 is doped with either an N-type or a P-type dopant. The conductive layer 204 serves as part of the emitter 208, which forms a PN junction with the substrate 200. When illuminated, both intrinsic and extrinsic absorption of photons by the substrate 200 generate photogenerated carriers. Photogenerated electrons in the P-region, photogenerated holes in the N-region, and electron-hole pairs (minority carriers) in the junction region diffuse to the vicinity of the junction electric field and drift across the junction under the influence of the built-in electric field. Photogenerated electrons are pulled towards the N-region, and photogenerated holes are pulled towards the P-region, thereby generating a current.

[0115] In some embodiments, such as Figure 16As shown, the first surface 201 of the solar cell has a tunneling dielectric layer 207 located on the first surface 201 of the first region 210; a doped conductive layer 214 located on the surface of the tunneling dielectric layer 207 away from the first surface 201, and the conductivity type of the doped conductive layer 214 is the same as that of the substrate 200; a second passivation layer 213 located on the doped conductive layer 214 and the first surface 201 of the second region 220; and a second electrode 241 penetrating the second passivation layer 213 and contacting the doped conductive layer 214.

[0116] It is understood that the passivation layer 205 is disposed in relation to the first passivation layer 109 of the above embodiment (see reference). Figure 1 The configuration of electrode 242 is the same as or similar to that of the first electrode 142 in the above embodiment (reference). Figure 1 The settings of the second passivation layer 213 are the same or similar to those of the passivation layer 105 in the above embodiment (see reference). Figure 1 The configuration of the second electrode 241 is the same as or similar to that of the electrode 141 in the above embodiment (reference). Figure 1 The settings are the same or similar; I won't go into too much detail here.

[0117] Furthermore, the doped layer, first part, second part, and conductive layer in the above embodiments also have the same design concept in the embodiments of this application. For example, the first region may have two first parts.

[0118] Figure 17 This is a seventh partial cross-sectional structural diagram of a solar cell provided in some embodiments of this application.

[0119] Accordingly, some embodiments of this application also provide a solar cell including a doped layer located within a first surface and a second surface, which will be referred to below. Figure 17 The following detailed description will be provided, and the same components as those in the above embodiments will not be repeated here.

[0120] refer to Figure 17The solar cell includes: a substrate 300, the surface of which has a first region 310 and a second region 320 spaced apart, at least one first region 310 including a first portion 311 and a second portion 312; a first doped layer 303 located within the substrate 300 adjacent to a first surface 301 of the first portion 311, the doping concentration of the first doped layer 303 being greater than the doping concentration of the substrate 300; a first conductive layer 304 located on the surface of the first region 310; a third passivation layer 305 located on the surfaces of the first conductive layer 304 and the second region 320; and a plurality of third electrodes 341 spaced apart along a first direction X, the third electrodes 341 extending along a second direction, each third electrode 341 facing the second portion 312. A first conductive layer 304 is disposed on the side away from the substrate 300 and electrically connected to the first conductive layer 304; a second doped layer 313 is located in the substrate 300 adjacent to the second surface 302 of the substrate 300, and the doping concentration of the second doped layer 313 is greater than the doping concentration of the substrate 300; a second conductive layer 314 is located on the surface of the first region 310; a fourth passivation layer 315 is located on the surfaces of the second conductive layer 314 and the second region 320; a plurality of fourth electrodes 342 are arranged at intervals along the first direction X, the fourth electrodes 342 extend along the second direction, each fourth electrode 342 is directly opposite the second part 312, the fourth electrode 342 is disposed on the side of the second conductive layer 314 away from the substrate 300 and electrically connected to the second conductive layer 314.

[0121] In some embodiments, the solar cell further includes a doped portion 306, which is the same as the doped portion 106 in the above embodiments (see reference). Figure 5 The doped portion 306 has the same configuration as the first conductive layer 304, for example, the doped portion 306 is formed by diffusion of the first conductive layer 304; the tunneling dielectric layer 307 is located between the first surface 301 and the first conductive layer 304, and the tunneling dielectric layer 307 has the same configuration as the tunneling dielectric layer 107 in the above embodiment (see reference). Figure 6 The same configuration, for example, tunneling dielectric layer 307 has a heavily doped portion 121 (reference). Figure 6 ).

[0122] It is understood that the arrangement of the reflector 308 is similar to that of the emitter 108 in the above embodiment (see reference). Figure 1 The settings of the fourth passivation layer 315 are the same or similar to those of the first passivation layer 109 in the above embodiment (see reference). Figure 1 The configuration of the fourth electrode 342 is the same as or similar to that of the first electrode 142 in the above embodiment (reference). Figure 1The settings of the third passivation layer 305 are the same or similar to those of the passivation layer 105 in the above embodiment (see reference). Figure 1 The configuration of the third electrode 341 is the same as or similar to that of the electrode 141 in the above embodiment (reference). Figure 1 The settings are the same or similar; I won't go into too much detail here.

[0123] Furthermore, the doped layer, first part, second part, and conductive layer in the above embodiments also have the same design concept in the first doped layer, second doped part, first part, second part, second conductive layer, and first conductive layer in the embodiments of this application. For example, the first region may have two first parts.

[0124] Figure 18 This is a schematic diagram of a photovoltaic module provided in some embodiments of this application.

[0125] Accordingly, embodiments of this application also provide a photovoltaic module, referencing Figure 18 The photovoltaic module includes: a cell string, which is formed by connecting multiple solar cells 40 provided in the above embodiments; an encapsulation layer 41 for covering the surface of the cell string; and a cover plate 42 for covering the surface of the encapsulation layer 41 away from the cell string. The solar cells 40 are electrically connected in a whole or in multiple segments to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel.

[0126] Specifically, in some embodiments, multiple battery strings can be electrically connected. The encapsulation layer 41 includes a first encapsulation layer 411 and a second encapsulation layer 412. The first encapsulation layer 411 covers one of the front or back sides of the solar cell 40, and the second encapsulation layer covers the other of the front or back sides of the solar cell 40. Specifically, at least one of the first encapsulation layer 411 or the second encapsulation layer 412 can be an organic encapsulation film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other light-transmitting cover plate. Specifically, the surface of the cover plate 42 facing the encapsulation layer 41 can be an uneven surface, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate 421 and a second cover plate 422. The first cover plate 421 is opposite to the first encapsulation layer 411, and the second cover plate 422 is opposite to the second encapsulation layer 412.

[0127] While this application discloses preferred embodiments as described above, it is not intended to limit the scope of the claims. Any person skilled in the art can make various possible variations and modifications without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims. Furthermore, the embodiments and accompanying drawings in this specification are merely illustrative and do not represent the full scope of protection of the claims.

[0128] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A solar cell, characterized in that, include: A substrate, the surface of which has a first region and a second region arranged at intervals, at least one of the first regions comprising: a first part and a second part; A doped layer is located only within the substrate of the first portion adjacent to the surface of the substrate; the concentration of the doped layer is higher than the concentration of the substrate. A conductive layer is located on the surface of the first region; the substrate is doped with either an N-type dopant or a P-type dopant, and the conductive layer is doped with either an N-type dopant or a P-type dopant. A passivation layer is located on the surface of the conductive layer and the second region; Multiple electrodes are spaced apart along a first direction and extend along a second direction. Each electrode is directly opposite to the second part and not directly opposite to the first part. The electrodes are disposed on the side of the conductive layer away from the substrate and are electrically connected to the conductive layer. The first region corresponds to the orthographic projection of the electrode onto the substrate, while the second region does not correspond to the orthographic projection of the electrode onto the substrate.

2. The solar cell according to claim 1, characterized in that, The doping concentration of the conductive layer is lower than that of the doped layer.

3. The solar cell according to claim 1, characterized in that, The doping concentration of the doped layer is 1E20~5E21cm. -3 .

4. The solar cell according to claim 1, characterized in that, The first region includes two first parts, with the second part located between adjacent first parts.

5. The solar cell according to claim 4, characterized in that, Along the first direction, the widths of the two first parts are equal.

6. The solar cell according to claim 1, characterized in that, Along the first direction, the size of the first spacing between the side of the doped layer facing the electrode and the side of the adjacent electrode facing the doped layer is proportional to the width of the contact surface between the electrode and the conductive layer.

7. The solar cell according to claim 6, characterized in that, The first spacing is less than or equal to 1 / 10 of the width of the contact surface between the electrode and the conductive layer.

8. The solar cell according to claim 1, characterized in that, Along the first direction, the difference between the width of the conductive layer and the width of the contact surface between the conductive layer and the electrode is a preset value; the ratio of the width of the first part to the preset value is in the range of 0.1 to 0.

9.

9. The solar cell according to claim 8, characterized in that, The width of the first part ranges from 20μm to 500μm.

10. The solar cell according to claim 1, characterized in that, The substrate includes a first surface and a second surface facing each other, and the doped layer is located within the first surface and / or the second surface.

11. The solar cell according to claim 1, characterized in that, Along a direction perpendicular to the surface of the substrate, the top surface of the second region, away from the substrate, is lower than the top surface of the first region.

12. The solar cell according to claim 11, characterized in that, The height difference between the top surface of the first region and the top surface of the second region ranges from 1 to 20 μm.

13. The solar cell according to claim 1, characterized in that, The first region has a first texture structure, which includes at least one first raised structure; the second region has a second texture structure, which includes at least one second raised structure. The one-dimensional dimension of the top surface of the first protrusion structure is smaller than the one-dimensional dimension of the top surface of the second protrusion structure; Alternatively, within a unit area, the number of the first protrusion structure is greater than or equal to the number of the second protrusion structure.

14. The solar cell according to claim 13, characterized in that, The first textured structure surface has a third textured structure, the third textured structure including at least one third protrusion structure located on the surface of the first protrusion structure.

15. The solar cell according to claim 14, characterized in that, The height between the top and bottom surfaces of the third protrusion is less than or equal to 2 μm.

16. A photovoltaic module, characterized in that, include: A battery string, wherein the battery string is formed by connecting a plurality of solar cells as described in any one of claims 1 to 15; Encapsulation layer, the encapsulation layer being used to cover the surface of the battery string; A cover plate for covering the surface of the encapsulation layer away from the battery string.

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