A solar cell and a photovoltaic module

Abstract

The embodiment of the present application relates to the photovoltaic field, and provides a solar cell and a photovoltaic module, wherein the solar cell comprises: a substrate; a tunneling dielectric layer located on the surface of the substrate; a doped conductive layer located on the surface of the tunneling dielectric layer, the doped conductive layer comprising a plurality of protrusions arranged along a first direction, the protrusions extending along a second direction, the first direction being perpendicular to the second direction; a conductive connection structure located between two adjacent protrusions and in contact with the side surface of the protrusions; a passivation layer covering the surface of the doped conductive layer and the conductive connection structure; and a plurality of auxiliary grid electrodes extending along the second direction and connected with the protrusions through the passivation layer. The performance of the solar cell can be improved at least.

Description

Cross-references to related applications

[0001] This application is a divisional application of Chinese invention patent application filed on June 27, 2022, with application number 202210745275.2 and invention title "A Solar Cell and Photovoltaic Module". Technical Field

[0002] This application relates to the photovoltaic field, and in particular to a solar cell and a photovoltaic module. Background Technology

[0003] With the energy shortage situation intensifying, the development and utilization of renewable energy is urgently needed. Among the many renewable energy sources, solar energy has outstanding advantages such as no risk of depletion, safety and reliability, no noise, no pollution emissions, and its application is not limited by the geographical distribution of resources.

[0004] Solar cells are used to convert solar energy into electrical energy, and therefore have a wide range of applications. Solar cells can be divided into crystalline silicon cells and thin-film cells. Among crystalline silicon cells, tunneling oxide passivation contact structure cells are favored due to their higher theoretical efficiency. Therefore, it is necessary to study tunneling oxide passivation contact structure cells with better performance. Summary of the Invention

[0005] This application provides a solar cell and a photovoltaic module, which at least helps to improve the performance of the tunnel oxide passivated contact structure cell.

[0006] According to some embodiments of this application, one aspect of this application provides a solar cell, comprising: a substrate; a tunneling dielectric layer located on the surface of the substrate; a doped conductive layer located on the surface of the tunneling dielectric layer, the doped conductive layer including a plurality of protrusions arranged along a first direction, the protrusions extending along a second direction, the first direction being perpendicular to the second direction; a conductive connection structure located between two adjacent protrusions and in contact with the side of the protrusions; a passivation layer covering the surfaces of the doped conductive layer and the conductive connection structure; and a plurality of sub-gate electrodes extending along the second direction, the sub-gate electrodes passing through the passivation layer and connected to the protrusions.

[0007] In some embodiments, there are multiple conductive connection structures, which are spaced apart along the first direction and / or the second direction, and at least one sub-gate electrode is provided between adjacent conductive connection structures along the first direction.

[0008] In some embodiments, the conductive connection structure is present between all adjacent sub-gate electrodes.

[0009] In some embodiments, a plurality of conductive connection structures are spaced apart between adjacent sub-gate electrodes.

[0010] In some embodiments, in the plurality of spaced conductive connection structures along the second direction, the spacing between adjacent conductive connection structures is equal.

[0011] In some embodiments, the spacing between adjacent conductive connection structures along the second direction is 0.01 mm to 20 mm.

[0012] In some embodiments, the array of multiple conductive connection structures includes multiple columns of multiple conductive connection structures arranged along the first direction and multiple conductive connection structures arranged along the second direction.

[0013] In some embodiments, the system further includes a main gate electrode that extends along the first direction and is electrically connected to a plurality of sub-gate electrodes arranged along the first direction.

[0014] In some embodiments, the conductive connection structure is spaced apart from the main gate electrode.

[0015] In some embodiments, the projection of the conductive connection structure onto the substrate at least partially coincides with the projection of the main gate electrode onto the substrate.

[0016] In some embodiments, the outermost main gate electrode has at least two columns of the plurality of conductive connection structures arranged along the first direction.

[0017] In some embodiments, the width of the conductive connection structure along the second direction is 10 μm to 500 μm.

[0018] In some embodiments, in a direction perpendicular to the substrate, the top surface of the conductive connection structure is lower than or flush with the top surface of the protrusion.

[0019] In some embodiments, the material of the conductive connection structure is the same as the material of the doped conductive layer.

[0020] In some embodiments, the material of the doped conductive layer may be one of doped amorphous silicon, doped polycrystalline silicon, or doped microcrystalline silicon.

[0021] In some embodiments, the doping type of the doped conductive layer is the same as the doping type of the substrate.

[0022] In some embodiments, the substrate is an N-type substrate, and the doped conductive layer is an N-type polycrystalline silicon layer.

[0023] According to some embodiments of this application, another aspect of this application also provides a photovoltaic module, including: a battery string, the battery string being formed by connecting multiple solar cells as described above; 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: a tunneling dielectric layer and the doped conductive layer are formed on the surface of the substrate, the doped conductive layer is located on the surface of the tunneling dielectric layer, and the doped conductive layer also includes protrusions arranged along a first direction. By providing protrusions arranged along the first direction, the parasitic light absorption of the doped conductive layer can be reduced. By providing a conductive connection structure connected to the protrusions between adjacent protrusions, the lateral transmission capability of the doped conductive layer can be increased. Attached Figure Description

[0025] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures 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 technology, 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.

[0026] Figure 1 This is a schematic diagram of the structure of a solar cell provided in one embodiment of this application; Figure 2 A cross-sectional schematic diagram of a solar cell provided in an embodiment of this application; Figure 3 A top view of a first type of solar cell provided in an embodiment of this application; Figure 4 A top view of a second type of solar cell provided in an embodiment of this application; Figure 5 A top view of a third type of solar cell provided in an embodiment of this application; Figure 6 A top view of a fourth type of solar cell provided in an embodiment of this application; Figure 7 A top view of a fifth type of solar cell provided in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application. Detailed Implementation

[0027] As is known from the background art, the parasitic light absorption capacity of the doped conductive layer currently leads to a decrease in the light utilization rate of solar cells. To solve the problem of parasitic light absorption capacity of the doped conductive layer, the thickness of the doped conductive layer is usually reduced. Therefore, a doped conductive layer structure with protrusions has been proposed. By setting a thicker doped conductive layer in the region where the sub-gate electrode is located and a thinner doped conductive layer in the region between the sub-gate electrodes, the parasitic light absorption of the doped conductive layer can be reduced. However, this structure brings a new problem, namely, the doped conductive layer in the region between the sub-gate electrodes is thin, which causes a large number of charge carriers to collide and be consumed during the transmission process due to the narrow lateral transport channel, thus affecting the transport rate of charge carriers.

[0028] This application embodiment provides a conductive contact structure connected to the protrusions between the protrusions. The conductive contact structure allows charge carriers to be transported during lateral transport, thereby increasing the lateral transport capability of charge carriers. Compared to a thick doped conductive layer, the solar cell provided by this application can also reduce parasitic light absorption of the doped conductive layer.

[0029] 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.

[0030] Figures 1 to 7 This is a schematic diagram of the structure of a solar cell provided in an embodiment of this application. Figure 1 This is a schematic diagram of the structure of a solar cell provided in one embodiment of this application. Figure 2 The following is provided as an embodiment of this application: Figure 1 A cross-sectional view along the direction of the dashed line AA; Figure 3 A top view of a first type of solar cell provided in an embodiment of this application. Figure 4 This is a top view of a second type of solar cell provided in an embodiment of this application. Figure 5 This is a top view of a third type of solar cell provided in an embodiment of this application. Figure 6 This is a top view of a fourth type of solar cell provided in an embodiment of this application. Figure 7 This is a top view of a fifth type of solar cell provided in an embodiment of this application.

[0031] refer to Figures 1 to 7The solar cell includes: a substrate 100; a tunneling dielectric layer 110 located on the surface of the substrate 100; a doped conductive layer 120 located on the surface of the tunneling dielectric layer 110, the doped conductive layer 120 including a plurality of protrusions 121 arranged along a first direction X, the protrusions 121 extending along a second direction Y, the first direction X being perpendicular to the second direction Y; a conductive connection structure 130 located between two adjacent protrusions 121 and in contact with the side of the protrusions 121; a passivation layer 140 covering the surfaces of the doped conductive layer 120 and the conductive connection structure 130; and a plurality of sub-gate electrodes 150 extending along the second direction Y, the sub-gate electrodes 150 passing through the passivation layer 140 and connecting to the protrusions 121. By providing the conductive connection structure 130, charge carriers between two adjacent protrusions 121 can be transported laterally through the conductive connection structure 130, thereby improving the lateral transport capability of the solar cell.

[0032] 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 other 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.

[0033] In some embodiments, the substrate 100 contains dopant elements of 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, the internal dopant element type is P-type. Alternatively, when the substrate 100 is an N-type substrate, the internal dopant element type is N-type.

[0034] In some embodiments, the tunneling dielectric layer 110 and the doped conductive layer 120 can constitute a passivation contact structure on the surface of the substrate 100. By forming the tunneling dielectric layer 110 and the doped conductive layer 120, the recombination of charge carriers on the battery surface can be reduced, increasing the open-circuit voltage of the battery and thus improving the battery efficiency. In some embodiments, the tunneling dielectric layer 110 can be located on the first surface of the substrate 100, which is the light-receiving surface facing sunlight. In some embodiments, the tunneling dielectric layer 110 can be located on the second surface of the substrate 100, which is the backlighting surface opposite the first surface. In some embodiments, the tunneling dielectric layer 110 can be located on both the first and second surfaces of the substrate 100. Figure 1(Not shown). It is understood that other layers located above the tunneling medium layer 110 are also synchronously disposed on the first and / or second surfaces of the substrate 100.

[0035] In some embodiments, the tunneling dielectric layer 110 may also be used to reduce or prevent the diffusion of dopants from the doped conductive layer 120 into the substrate 100.

[0036] In some embodiments, the material of the tunneling dielectric layer 110 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. Specifically, the tunneling dielectric layer 110 may be formed of a silicon oxide layer including silicon oxide (SiOx), which has good passivation properties and allows charge carriers to easily tunnel through the silicon oxide layer.

[0037] In some embodiments, the thickness of the tunneling dielectric layer 110 can be 0.5 nm to 2.5 nm. Optionally, the thickness of the tunneling dielectric layer 110 is 0.5 nm to 2 nm, and further, the thickness of the tunneling dielectric layer 110 is 0.5 nm to 1.2 nm. When the thickness of the tunneling dielectric layer 110 is less than 0.5 mm, the process of forming the tunneling dielectric layer 110 is more difficult; when the thickness of the tunneling dielectric layer 110 is greater than 2.5 mm, the tunneling effect is weaker.

[0038] In some embodiments, the material of the conductive connection structure 130 is the same as the material of the doped conductive layer 120. By making the conductive connection structure 130 and the doped conductive layer 120 the same material, the number of material types in the entire production process can be reduced, which facilitates management. For example, the material of the conductive connection structure 130 includes at least one of polycrystalline silicon, amorphous silicon, and microcrystalline silicon.

[0039] In some embodiments, the conductive connection structure 130 can be formed simultaneously with the protrusion 121 of the doped conductive layer 120. That is, the protrusion 121 and the conductive connection structure 130 are formed by etching the doped conductive layer 120 in the same process step. Forming the protrusion 121 and the conductive connection structure 130 in one step ensures the reliability of the connection between the protrusion 121 and the conductive connection structure 130, and also reduces the number of production steps in the manufacturing process, thus reducing production time. In other embodiments, the protrusion and the conductive connection structure can be formed separately.

[0040] In some embodiments, the material of the doped conductive layer 120 may be one of doped amorphous silicon, doped polycrystalline silicon, or doped microcrystalline silicon. In other embodiments, the doped conductive layer 120 may be other materials, which may be selected according to the actual situation, such as silicon carbide.

[0041] In some embodiments, the doped conductive layer 120 may be formed by first forming a conductive layer on the surface of the tunneling dielectric layer 110, and then doping the conductive layer to form the doped conductive layer 120.

[0042] In some embodiments, the thickness of the doped conductive layer 120 ranges from 40 nm to 150 nm. Optionally, the thickness of the doped conductive layer 120 ranges from 60 nm to 90 nm. This thickness range ensures that the optical loss of the doped conductive layer 120 is small and the interface passivation effect of the tunneling dielectric layer 110 is good, thereby improving the battery efficiency. In the embodiments of this application, the material of the doped conductive layer can be polycrystalline silicon.

[0043] In some embodiments, the doping type of the conductive layer 120 is the same as the doping type of the substrate 100. It is understood that when the doping type of the substrate 100 is N-type and the doping type of the conductive layer 120 is P-type, the majority carriers of the substrate 100 are electrons and the majority carriers of the conductive layer 120 are holes. The two will recombine and dissolve directly, resulting in fewer charge carriers collected by the sub-gate electrode 150. Therefore, making the doping type of the conductive layer 120 the same as the doping type of the substrate 100 can prevent the sub-gate electrode 150 from collecting fewer charge carriers.

[0044] In some embodiments, the substrate 100 is an N-type substrate, and the doped conductive layer 120 is an N-type polysilicon layer; in other embodiments, the substrate may also be a P-type substrate, and the doped conductive layer may be a P-type polysilicon layer. N-type substrates and N-type polysilicon layers have high photoelectric conversion efficiency, while the formation process of P-type substrates and P-type polysilicon layers is simple and can be selected according to actual conditions. This application does not limit the substrate 100 or the doped conductive layer 120.

[0045] In some embodiments, both the conductive connection structure 130 and the protrusion 121 are formed by etching the doped conductive layer 120. The protrusion 121 and the conductive connection structure 130 can be formed in the same process step by setting the shape of the doped conductive layer 120 and then etching the doped conductive layer 120.

[0046] In some embodiments, the passivation layer 140 may be an antireflective film layer, thereby reducing the emitted light from the surface of the solar cell and increasing the light transmittance of the solar cell. The passivation layer 140 may be a single-layer structure or a multilayer structure, and the material of the passivation layer 140 may be one or more of the following: silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, titanium oxide, hafnium oxide, or aluminum oxide. In some embodiments, the passivation layer 140 may be a hydrogen-containing passivation layer, such as silicon hydroxide, silicon hydrogen nitride, or silicon hydrogen oxynitride.

[0047] In some embodiments, the sub-grid electrode 150 is used to collect and summarize the current of the solar cell. The sub-grid electrode 150 may be formed by sintering a burn-through paste. The material of the sub-grid electrode 150 may be one or more of aluminum, silver, gold, nickel, molybdenum, or copper. In some cases, the sub-grid electrode 150 refers to fine grid lines or finger grid lines to distinguish it from the main grid electrode lines or busbars.

[0048] refer to Figures 3 to 7 In some embodiments, there are multiple conductive connection structures 130, which are spaced apart along a first direction X and / or a second direction Y. Along the first direction X, there is at least one sub-gate electrode 150 between adjacent conductive connection structures 130. In other words, the multiple conductive connection structures 130 can be spaced apart along the first direction X, or spaced apart along the second direction Y, or spaced apart along both the first direction X and the second direction Y. Along the first direction X, there is at least one sub-gate electrode 150 between adjacent conductive connection structures 130. When there is one sub-gate electrode 150 between adjacent conductive connection structures 130, there is a conductive connection structure 130 between every two adjacent protrusions. When there are multiple sub-gate electrodes 150 between adjacent conductive connection structures 130, the conductive connection structures 130 can be spaced apart. For example, in the first direction, there is a conductive connection structure 130 between the first sub-gate electrode and the second sub-gate electrode, but no conductive connection structure 130 between the second sub-gate electrode and the third sub-gate electrode. By setting at least one sub-gate electrode 150 between adjacent conductive connection structures 130, the lateral transmission capability of the solar cell can be increased.

[0049] It should be noted that the first, second, and third sub-gate electrodes mentioned above are for illustrative purposes only and do not limit the sub-gate electrode 150.

[0050] refer to Figure 3 and Figure 4 In some embodiments, all adjacent sub-gate electrodes 150 are provided with a conductive connection structure 130, that is, every two sub-gate electrodes 150 are provided with a conductive connection structure 130. By providing a conductive connection structure 130 between every two sub-gate electrodes 150, the lateral transmission capability between adjacent protrusions 121 can be improved.

[0051] refer to Figure 6In some embodiments, a conductive connection structure 130 is provided between some adjacent sub-gate electrodes 150, while no conductive connection structure 130 is provided between some adjacent sub-gate electrodes 150. Furthermore, the conductive connection structures 130 can be arranged in a regular pattern in the first direction. For example, there is a conductive connection structure 130 between the first and second sub-gate electrodes, no conductive connection structure 130 between the second and third sub-gate electrodes, a conductive connection structure 130 between the third and fourth sub-gate electrodes, and so on; or there is a conductive connection structure 130 between the first and second sub-gate electrodes, a conductive connection structure 130 between the second and third sub-gate electrodes, no conductive connection structure 130 between the third and fourth sub-gate electrodes, a conductive connection structure 130 between the fourth and fifth sub-gate electrodes, and so on, in a regular pattern. Alternatively, the conductive connection structures 130 may not be arranged in a regular pattern.

[0052] It should be noted that the above rule arrangement is only an example for illustrative purposes, and other rule arrangements are also possible.

[0053] refer to Figure 3 In some embodiments, there are multiple spaced conductive connection structures 130 between adjacent sub-gate electrodes 150. That is, there are multiple conductive connection structures 130 spaced along the second direction between adjacent sub-gate electrodes 150. By providing multiple conductive connection structures 130 between adjacent sub-gate electrodes 150, the lateral transmission capability between adjacent sub-gate electrodes 150 can be increased. Moreover, compared to providing only one conductive connection structure 130 between adjacent sub-gate electrodes 150, the enhanced lateral transmission capability is stronger by providing multiple conductive connection structures 130.

[0054] In some embodiments, in a plurality of spaced conductive connection structures 130 along the second direction Y, the spacing between adjacent conductive connection structures 130 is equal. By setting the conductive connection structures 130 with equal spacing, the laser ablation process during the formation process is facilitated, that is, the spacing between adjacent conductive connection structures does not need to be adjusted, thereby facilitating production.

[0055] In some embodiments, the spacing between adjacent conductive connection structures 130 along the second direction is 0.01mm to 20mm, for example, 0.1mm, 0.5mm, or 10mm. When the spacing between conductive connection structures 130 is less than 0.01mm, the conductive connection structures 130 are too densely packed, resulting in severe light absorption and hindering the improvement of the photoelectric conversion efficiency of the solar cell. When the spacing between conductive connection structures 130 is greater than 20mm, the number of conductive connection structures 130 is too small, leading to poor improvement. In other embodiments, the spacing between adjacent conductive connection structures 130 can also be other values, which can be adjusted according to actual conditions. This application does not limit the spacing between conductive connection structures 130.

[0056] refer to Figure 3 , Figure 6 and Figure 7 In some embodiments, multiple conductive connection structures 130 are arranged in an array, including multiple columns of conductive connection structures 130 arranged along the first direction X and multiple conductive connection structures 130 arranged along the second direction Y. That is, the conductive connection structures 130 are arranged regularly in both the first direction X and the second direction Y. By arranging multiple conductive connection structures 130 in an array, the lateral transmission capability of the solar cell can be increased while the process difficulty of forming multiple conductive connection structures 130 can be reduced.

[0057] In one embodiment, taking four columns of conductive connection structures 130 arranged along the first direction X as an example, the conductive connection structures are arranged sequentially along the first direction X as a first column, a second column, a third column, and a fourth column. Each conductive connection structure in the first, second, third, and fourth columns can be arranged in the same row in the second direction. In other embodiments, the first and second columns of conductive connection structures may not be located in the same row, that is, the first and second columns of conductive connection structures may be staggered in the second direction; or some of the first and second columns of conductive connection structures may be arranged in the same row. This application does not limit the conductive connection structures 130, only requiring that the multiple conductive connection structures 130 be arranged in an array.

[0058] In some embodiments, the width of the conductive connection structure 130 along the second direction Y is 10 μm to 500 μm, for example, 50 μm, 80 μm, or 100 μm. It is understood that when the width of the conductive connection structure 130 is less than 10 μm, the lateral transmission capability of each conductive connection structure 130 is weak, resulting in poor improvement; when the width of the conductive connection structure 130 is greater than 500 μm, the conductive connection structure 130 itself may have a high parasitic light absorption capacity, which is detrimental to improving the photoelectric conversion efficiency of the solar cell. In other embodiments, the width of the conductive connection structure 130 can also be other dimensions, which can be adjusted according to actual conditions.

[0059] In some embodiments, the top surface of the conductive connection structure 130 is lower than or flush with the top surface of the protrusion 121. In other words, in the direction perpendicular to the surface of the substrate 100, the thickness of the conductive connection structure 130 is less than or equal to the thickness of the protrusion 121. When the top surface of the conductive connection structure 130 is lower than the top surface of the protrusion 121, the light absorption capacity of the conductive connection structure 130 is reduced, thereby improving the photoelectric conversion efficiency of the solar cell. When the top surface of the conductive connection structure 130 is flush with the top surface of the protrusion 121, the manufacturing process of the solar cell can be simplified, and the protrusion 121 and the conductive connection structure 130 can be formed in the same step by laser ablation. In other embodiments, the top surface of the conductive connection structure may be higher than the top surface of the protrusion, which can be adjusted according to the actual situation.

[0060] In some embodiments, in the direction perpendicular to the surface of the substrate 100, the height of the conductive connection structure 130 can be 0.5 to 1.2 times the height of the protrusion 121. When the height of the conductive connection structure 130 is less than 0.5 times the height of the protrusion 121, the thickness of the conductive connection structure 130 is relatively thin, resulting in a weak improvement in lateral transmission capability and an insignificant improvement. When the height of the conductive connection structure 130 is greater than 1.2 times the height of the protrusion 121, the thickness of the conductive connection structure 130 is relatively thick, resulting in a stronger parasitic light absorption capability of the conductive connection structure 130, which in turn affects the photoelectric conversion efficiency of the solar cell.

[0061] In some embodiments, the system further includes a main grid electrode 160, which extends along a first direction X and is electrically connected to a plurality of sub-grid electrodes 150 arranged along the first direction X. By configuring the main grid electrode 160, the current collected on the sub-grid electrodes 150 can be collected and discharged from the solar cell.

[0062] In some embodiments, the conductive connection structure 130 is spaced apart from the main gate electrode 160. It is understood that by setting the conductive connection structure 130 to be spaced apart from the main gate electrode 160, the main gate electrode 160 can be limited by the conductive connection structure 130, thereby facilitating the subsequent printing of the main gate electrode 160. Thus, the position of the main gate electrode 160 can be determined without additional positioning processing, which can facilitate the process production steps.

[0063] In some embodiments, a column of conductive connection structures 130 spaced apart along the first direction X can be provided between adjacent main gate electrodes 160. In other embodiments, multiple columns of conductive connection structures 130 spaced apart along the first direction X can also be provided between adjacent main gate electrodes 160. This application does not limit the number of conductive connection structures 130 between main gate electrodes 160, and can adjust them according to actual conditions.

[0064] In some embodiments, the projection of the conductive connection structure 130 on the substrate 100 at least partially overlaps with the projection of the main grid electrode 160 on the substrate 100. It is understood that the main grid electrode 160 is typically non-sintered and is usually used to collect photogenerated carriers collected on the sub-grid electrode 150. That is, the main grid electrode 160 does not corrode the structure located on the bottom surface of the main grid electrode 160. Therefore, providing the conductive connection structure 130 on the bottom surface of the main grid electrode 160 will not affect the conductive connection structure 130, and will not affect the lateral transport capability of the conductive connection structure 130. Furthermore, by providing the main grid electrode 160 to block at least part of the conductive connection structure 130, the parasitic light absorption capability of the conductive connection structure 130 can be reduced, thereby improving the photoelectric conversion efficiency of the solar cell.

[0065] In some embodiments, the outermost main grid electrode 160 has at least two columns of multiple conductive connection structures 130 arranged along the first direction X. In other embodiments, the conductive connection structures arranged along the first direction may not be provided on the outer side of the main grid electrode, or only one column of conductive connection structures arranged along the first direction may be provided on the outer side of the main grid electrode. By providing at least two columns of conductive connection structures 130, the number of conductive connection structures 130 can be increased, thereby improving the lateral transmission capability of the solar cell.

[0066] In some embodiments, the solar cell includes a front side and a back side, wherein the front side is a light-receiving surface that absorbs incident light, and the back side is a surface opposite to the front side. A tunneling dielectric layer 110, a doped conductive layer 120, a conductive connection structure 130, a passivation layer 140, and a sub-gate electrode 150 may be disposed on the front side and the back side of the solar cell.

[0067] In some embodiments, the doping type of the doped conductive layer 120 on the back of the solar cell is the same as the doping type of the substrate 100, and the doping type of the doped conductive layer 120 on the front of the solar cell is opposite to the doping type of the substrate 100. Taking the substrate 100 as an N-type substrate as an example, the doping type of the doped conductive layer 120 on the back of the solar cell is N-type, and the doping type of the doped conductive layer 120 on the front of the solar cell is P-type.

[0068] In this embodiment, a tunneling dielectric layer 110 and a doped conductive layer 120 are formed on the surface of a substrate 100. The doped conductive layer 120 has protrusions 121. By forming a height difference on the doped conductive layer 120, the parasitic light absorption of the doped conductive layer 120 is reduced while ensuring contact between the sub-gate electrode 150 and the doped conductive layer 120. A conductive connection structure 130 is provided between the protrusions 121 of the doped conductive layer 120 to connect two adjacent protrusions 121, thereby increasing the lateral transmission capability of the doped conductive layer 120 and improving the transmission rate of the solar cell.

[0069] Accordingly, refer to Figure 8 In another aspect, this application also provides a photovoltaic module for converting received light energy into electrical energy and transmitting it to an external load. The photovoltaic module includes: at least one cell string, the cell string consisting of multiple of the above-mentioned (e.g., Figures 1-4 The battery string is formed by connecting any one of the solar cells 10; an encapsulating film 21 is used to cover the surface of the battery string; and a cover plate 22 is used to cover the surface of the encapsulating film 21 that is away from the battery string.

[0070] The encapsulating film 21 can be an organic encapsulating film such as EVA or POE, and it covers the surface of the battery string to seal and protect it. In some embodiments, the encapsulating film 21 includes an upper encapsulating film and a lower encapsulating film respectively covering both sides of the surface of the battery string. The cover plate 22 can be a glass cover plate or a plastic cover plate, used to protect the battery string, and it covers the surface of the encapsulating film 21 facing away from the battery string. In some embodiments, the cover plate 22 is provided with a light-trapping structure to increase the utilization rate of incident light. Photovoltaic modules have high current collection capability and low carrier recombination rate, enabling high photoelectric conversion efficiency. In some embodiments, the cover plate 22 includes an upper cover plate and a lower cover plate located on both sides of the battery string.

[0071] Those skilled in the art will understand that the above-described embodiments are specific examples of implementing this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of the embodiments of this application. Any person skilled in the art can make their own modifications and alterations without departing from the spirit and scope of the embodiments of this application; therefore, the scope of protection of the embodiments of this application should be determined by the scope defined in the claims.

Claims

1. A solar cell, characterized in that, include: The substrate includes the light-receiving surface and the back-lighting surface; A tunneling dielectric layer, wherein the tunneling dielectric layer is located on at least one of the light-receiving surface and the back-lighting surface of the substrate; A doped conductive layer is located on the surface of the tunneling dielectric layer. The doped conductive layer includes a plurality of protrusions arranged along a first direction and extending along a second direction, wherein the first direction is perpendicular to the second direction. A conductive connection structure is located between two adjacent protrusions and is in contact with the side of the protrusion; A passivation layer, the passivation layer covering the surface of the doped conductive layer and the conductive connection structure; Multiple sub-gate electrodes extend along the second direction and pass through the passivation layer to connect with the protrusion.

2. The solar cell according to claim 1, characterized in that, The material of the doped conductive layer includes one of doped amorphous silicon, doped polycrystalline silicon, or doped microcrystalline silicon.

3. The solar cell according to claim 1, characterized in that, The doping type of the doped conductive layer is the same as the doping type of the substrate.

4. The solar cell according to claim 3, characterized in that, The substrate includes an N-type substrate, and the doped conductive layer includes an N-type polycrystalline silicon layer.

5. The solar cell according to any one of claims 1 to 4, characterized in that, The conductive connection structure is a plurality of such structures, which are spaced apart along the first direction and / or the second direction. Along the first direction, there is at least one sub-gate electrode between adjacent conductive connection structures.

6. The solar cell according to claim 5, characterized in that, The conductive connection structure is present between all adjacent sub-gate electrodes.

7. The solar cell according to claim 5, characterized in that, Between adjacent sub-gate electrodes, there are multiple spaced conductive connection structures.

8. The solar cell according to claim 7, characterized in that, Along the second direction, in the plurality of spaced conductive connection structures, the spacing between adjacent conductive connection structures is equal.

9. The solar cell according to claim 7, characterized in that, Along the second direction, the spacing between adjacent conductive connection structures is 0.01 mm to 20 mm.

10. The solar cell according to claim 5, characterized in that, The conductive connection structure is provided between some of the adjacent sub-gate electrodes.

11. The solar cell according to any one of claims 1 to 4, characterized in that, The array of multiple conductive connection structures includes multiple columns of multiple conductive connection structures arranged along the first direction and multiple conductive connection structures arranged along the second direction.

12. The solar cell according to claim 11, characterized in that, In the conductive connection structures of adjacent columns, at least one conductive connection structure in one column is misaligned with the corresponding conductive connection structure in the other column along the second direction.

13. The solar cell according to any one of claims 1 to 4, characterized in that, Also includes: A main gate electrode extends along the first direction and is electrically connected to a plurality of sub-gate electrodes arranged along the first direction.

14. The solar cell according to claim 13, characterized in that, The conductive connection structure is spaced apart from the main gate electrode.

15. The solar cell according to claim 13, characterized in that, The outermost main gate electrode has at least two columns of the plurality of conductive connection structures arranged along the first direction.

16. The solar cell according to any one of claims 1 to 4, characterized in that, Along the second direction, the width of the conductive connection structure is 10 μm to 500 μm.

17. The solar cell according to any one of claims 1 to 4, characterized in that, In a direction perpendicular to the substrate, the top surface of the conductive connection structure is lower than or flush with the top surface of the protrusion.

18. The solar cell according to any one of claims 1 to 4, characterized in that, The material of the conductive connection structure is the same as the material of the doped conductive layer.

19. The solar cell according to any one of claims 1 to 4, characterized in that, In the direction perpendicular to the light-receiving surface, the ratio of the height of one of the conductive connection structures to the height of one of the protrusions is 0.5 to 1.

2.

20. 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 19; 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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