Back contact solar cell and photovoltaic module
By not installing doped layers in the perimeter area around the back surface of the silicon substrate in which the back contact solar cells are in the back contact solar cells, and doping layers and dielectric layers are interlaced, the leakage risk of back contact solar cells is solved, and the reliability and photoelectric conversion efficiency of the battery are improved.
Patent Information
- Application Number
- CN202422490848.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-15
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2034-10-15
AI Technical Summary
Existing back contact solar cells have a risk of leakage in the area around the back surface of the silicon substrate, resulting in safety hazards and performance attenuation.
No doped layers are provided in the perimeter area of the back surface of the silicon substrate, only undoped regions are retained, and the first and second doped layers are arranged interlaced between the doped layers, combining the dielectric layer and the electrode structure to form an effective current collection path.
It reduces leakage at the edge of the battery, improves the long-term reliability and photoelectric conversion rate of the battery, and reduces the carrier recombination loss.
Smart Images
Figure CN223219421U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cells, and in particular to a back-contact solar cell and a photovoltaic module. Background Art
[0002] BC (Back Contact) solar cells are a high-efficiency photovoltaic cell technology with the following advantages: No front-side shading, thus increasing short-circuit current; no front-side metal contact composite, which helps to increase open-circuit voltage and output power; and strong compatibility, allowing them to be combined with other high-efficiency photovoltaic technologies to enhance cell performance. With technological advancements and cost reductions, BC solar cells are expected to occupy a more important position in the solar cell market, promoting the development and application of solar technology.
[0003] Currently, BC solar cells have an N-type doped layer and a P-type doped layer on the back. The N-type doped layer and the P-type doped layer are located around the cell, which poses a greater risk of defects and leakage. Utility Model Content
[0004] This application provides a back-contact solar cell and photovoltaic module to solve or alleviate the technical problems mentioned above. The back-contact solar cell in the technical solution of this application does not have a doping layer in the peripheral area of the back side of the silicon substrate, which can reduce the risk of leakage and alleviate safety hazards.
[0005] In a first aspect, an embodiment of the present application provides a back-contact solar cell, comprising:
[0006] A silicon substrate, the silicon substrate comprising a front surface and a back surface arranged opposite to each other;
[0007] The back side of the silicon substrate has a doped region and an undoped region, and the undoped region is located in a peripheral region of the back side of the silicon substrate;
[0008] The doping region includes a first doping layer and a second doping layer that are alternately arranged, and the doping type of the first doping layer is opposite to the doping type of the second doping layer.
[0009] Optionally, the width of the undoped region is 1×10 -6 -1.5cm.
[0010] Optionally, the back-contact solar cell further includes:
[0011] a dielectric layer located on the first doped layer and the second doped layer; wherein the dielectric layer comprises a passivation layer and an anti-reflection layer stacked in sequence in a direction away from the substrate;
[0012] a first electrode penetrating the dielectric layer and contacting the first doped layer; and
[0013] A second electrode penetrates the dielectric layer and contacts the second doped layer.
[0014] Optionally, the second doping layer and the adjacent first doping layer are in contact with each other only at side surfaces.
[0015] Optionally, there is a gap between the second doping layer and the adjacent first doping layer, and the width of the gap is 0.1-500 μm.
[0016] Optionally, the second doping layer and the adjacent first doping layer are in contact with each other at side surfaces, and a portion of the second doping layer is located above the adjacent first doping layer and exposes at least a portion of the adjacent first doping layer.
[0017] Optionally, the first doped layer includes a first silicon oxide layer and a first doped polysilicon layer stacked in sequence, wherein the first silicon oxide layer is close to the silicon substrate, and the first doped polysilicon layer is far away from the silicon substrate;
[0018] or
[0019] The first doped layer includes a first intrinsic amorphous silicon layer and a first doped amorphous silicon layer stacked in sequence, wherein the first intrinsic amorphous silicon layer is close to the silicon substrate, and the first doped amorphous silicon layer is far away from the silicon substrate.
[0020] Optionally, the second doped layer includes a second silicon oxide layer and a second doped polysilicon layer stacked in sequence, wherein the second silicon oxide layer is close to the silicon substrate, and the second doped polysilicon layer is far away from the silicon substrate;
[0021] or
[0022] The second doped layer includes a second intrinsic amorphous silicon layer and a second doped amorphous silicon layer stacked in sequence, wherein the second intrinsic amorphous silicon layer is close to the silicon substrate, and the second doped amorphous silicon layer is far away from the silicon substrate.
[0023] Optionally, a surface of the first doped layer close to the silicon substrate is not flush with a surface of the second doped layer close to the silicon substrate.
[0024] In a second aspect, an embodiment of the present application provides a photovoltaic module comprising the back-contact solar cell described in any one of the above embodiments.
[0025] The above technical solution adopted in the embodiments of the present application may have the following advantages:
[0026] Back-contact solar cells have an undoped region located in the peripheral area of the back side of the silicon substrate. That is, the peripheral area of the back side of the silicon substrate does not have a doped layer. By removing the doped layer in the peripheral area of the back side of the silicon substrate to obtain the undoped region, leakage at the edge of the cell can be reduced. At the same time, the performance degradation caused by edge leakage can be reduced, thereby improving the long-term reliability of the cell. In addition, since the peripheral area of the cell is usually not covered with metal electrodes, if the peripheral area of the back side of the silicon substrate has a doped layer, the carriers are easily recombined and cannot be collected. However, if the peripheral area of the back side of the silicon substrate does not have a doped layer, more carriers can be collected, improving the photoelectric conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.
[0028] Figure 1 Schematic diagram of the structure of the doped region and the undoped region of the back contact solar cell of Example 1 of the present application;
[0029] Figure 2 1 is a schematic structural diagram of a back-contact solar cell according to Example 1 of the present application;
[0030] Figure 3 2 is a schematic structural diagram of a back-contact solar cell according to Example 2 of the present application;
[0031] Figure 4 It is a schematic structural diagram of the back-contact solar cell of Example 3 of the present application.
[0032] Description of reference numerals:
[0033] 100. Silicon substrate;
[0034] 200, doped region; 210, first doped layer; 211, first silicon oxide layer; 212, first doped polysilicon layer; 220, second doped layer; 221, second silicon oxide layer; 222, second doped polysilicon layer;
[0035] 300, undoped region; W1, width of the undoped region;
[0036] 400, dielectric layer; 410, passivation layer; 420, anti-reflection layer;
[0037] 510, first electrode; 520, second electrode. DETAILED DESCRIPTION
[0038] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, the sizes of layers, regions, and elements and their relative sizes may be exaggerated for clarity. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other unless there is a conflict.
[0039] like Figures 1 to 4 As shown, an embodiment of the present application provides a back-contact solar cell, comprising:
[0040] A silicon substrate 100, wherein the silicon substrate 100 includes a front surface and a back surface that are oppositely disposed;
[0041] The back side of the silicon substrate 100 has a doped region 200 and an undoped region 300 , wherein the undoped region 300 is located in a peripheral region of the back side of the silicon substrate 100 ;
[0042] The doping region 200 includes first doping layers 210 and second doping layers 220 that are alternately arranged. The doping type of the first doping layer 210 is opposite to that of the second doping layer 220 .
[0043] Back-contact solar cells can maximize the use of the surface area of the silicon substrate to absorb sunlight by staggering the first doping layer and the second doping layer on the back side to form different doping type structures, more efficiently collect the current generated by photogenerated carriers, and help form a good current collection path.
[0044] In the embodiment of the present application, the back-contact solar cell has an undoped region located in the peripheral area of the back side of the silicon substrate, that is, the peripheral area of the back side of the silicon substrate does not have a doped layer. By removing the doped layer in the peripheral area of the back side of the silicon substrate to obtain the undoped region, leakage at the edge of the cell can be reduced, and at the same time, performance degradation caused by edge leakage can be reduced, thereby improving the long-term reliability of the cell. In addition, since the peripheral area of the cell is usually not covered with a metal electrode, if the peripheral area of the back side of the silicon substrate has a doped layer, carriers are easily recombined and cannot be collected. However, if the peripheral area of the back side of the silicon substrate does not have a doped layer, more carriers can be collected, thereby improving the photoelectric conversion rate.
[0045] It should be noted that, in the present application, the doping type of the first doping layer and the doping type of the second doping layer are opposite, that is, when the first doping layer is an N-type doping layer, the second doping layer is a P-type doping layer; or, when the first doping layer is a P-type doping layer, the second doping layer is an N-type doping layer.
[0046] When removing the doping layer in the peripheral area of the back side of the silicon substrate, the doping layer on the side of the silicon substrate can also be removed at the same time, thereby ensuring that there is no doping layer on the side of the silicon substrate. This can further reduce leakage at the edge of the battery and improve the long-term reliability of the battery.
[0047] like Figure 1 As shown, in some embodiments, the width W1 of the undoped region is 1×10 -6 -1.5cm. If the width of the undoped area is too small, the risk of leakage will increase; if the width of the undoped area is too large, the doped area will be smaller, the effective power generation area will be reduced, and the power generation efficiency will be affected. Specifically, the width of the undoped area can be 1×10 -6 cm, 1×10 -5 cm, 1×10 -4 cm, 1×10 -3 cm, 1×10 -2 cm, 0.1cm, 0.2cm, 0.5cm, 0.8cm, 1cm, 1.3cm or 1.5cm.
[0048] like Figures 2 to 4 As shown, in some embodiments, the back contact solar cell further includes:
[0049] A dielectric layer 400 is located on the surface of the first doped layer 210 and the surface of the second doped layer 220; wherein the dielectric layer 400 includes a passivation layer 410 and an anti-reflection layer 420 stacked in sequence in a direction away from the substrate;
[0050] a first electrode 510 penetrating the dielectric layer 400 and contacting the first doping layer 210 ; and
[0051] The second electrode 520 penetrates the dielectric layer 400 and contacts the second doping layer 220 .
[0052] In the embodiments of the present application, the dielectric layer and electrodes ensure the integrity of the battery structure. The dielectric layer on the back side of the silicon substrate has excellent insulation properties, preventing direct electrical contact between the electrodes and the silicon substrate, thereby avoiding short circuits and extending the battery's service life. In some embodiments, a dielectric layer can also be provided on the front side of the silicon substrate to further improve battery performance.
[0053] like Figure 2As shown, in some embodiments, the second doped layer 220 and the adjacent first doped layer 210 only contact each other on the side surface. When the second doped layer 220 and the adjacent first doped layer 210 only contact each other on the side surface, the first doped layer 210 and the second doped layer 220 are both completely in contact with the subsequently formed dielectric layer 400, providing contact surfaces for the subsequent formation of the first electrode 510 and the second electrode 520, respectively; the first electrode 510 penetrates the dielectric layer 400 and contacts the first doped layer 210, and the second electrode 520 penetrates the dielectric layer 400 and contacts the second doped layer 220. When the second doped layer and the adjacent first doped layer only contact each other on the side surface, the surface height of the first doped layer and the surface height of the second doped layer can be the same or different, and are not specifically limited here.
[0054] like Figure 3 As shown, in some embodiments, there is a gap between the second doping layer 220 and the adjacent first doping layer 210, and the width of the gap is 0.1-500μm. The adjacent first doping layer does not contact the second doping layer, and there is a gap between the second doping layer and the adjacent first doping layer. The existence of the gap can reduce the surface recombination of carriers in the electrode contact area, thereby improving the open circuit voltage and overall performance of the battery. However, if the gap is too large, it will increase the series resistance of the battery, affect the current collection efficiency, thereby reducing the overall performance of the battery, and affect the battery's utilization of sunlight and affect the optical performance of the battery. Specifically, the width of the gap can be 0.1μm, 0.5μm, 1μm, 5μm, 10μm, 30μm, 50μm, 100μm, 200μm, 300μm, 400μm or 500μm. When adjacent first doped layers 210 and second doped layers 220 are not in contact, the first doped layers 210 and the second doped layers 220 are completely in contact with the subsequently formed dielectric layer 400, providing contact surfaces for the subsequent formation of the first electrode 510 and the second electrode 520, respectively. The first electrode 510 penetrates the dielectric layer 400 and contacts the first doped layer 210, while the second electrode 520 penetrates the dielectric layer 400 and contacts the second doped layer 220. When a second doped layer is spaced apart from an adjacent first doped layer, the surface height of the first doped layer and the surface height of the second doped layer may be the same or different, and is not specifically limited herein.
[0055] like Figure 4 As shown, in some embodiments, the second doping layer 220 contacts the adjacent first doping layer 210 at the side surface, and a portion of the second doping layer 220 is located above the adjacent first doping layer 210 and exposes at least a portion of the adjacent first doping layer 210 .
[0056] In the embodiment of the present application, since a portion of the second doping layer 220 is located above the adjacent first doping layer 210, the surface height of this portion of the second doping layer 220 is higher than the surface height of the first doping layer 210. The surface height of the remaining portion of the second doping layer 220 may be the same as or different from the surface height of the first doping layer 210, and is not specifically limited herein. The second doping layer 220 located around the first doping layer 210 does not completely cover the first doping layer 210, but at least partially exposes the first doping layer 210, so that the exposed portion of the first doping layer 210 can contact the subsequently formed electrode. When a portion of the second doped layer 220 is located above the adjacent first doped layer 210, a dielectric layer 400 is formed on the second doped layer 220 and the exposed first doped layer 210, and a second electrode 520 is formed on the dielectric layer 400 located on the second doped layer 220. The second electrode 520 penetrates the dielectric layer 400 and contacts the second doped layer 220. A first electrode 510 is formed on the dielectric layer 400 located on the exposed first doped layer 210. The first electrode 510 penetrates the dielectric layer 400 and contacts the exposed portion of the first doped layer 210.
[0057] like Figures 2 to 4 As shown, in some embodiments, the first doped layer 210 includes a first silicon oxide layer 211 and a first doped polysilicon layer 212 stacked in sequence, wherein the first silicon oxide layer 211 is close to the silicon substrate 100, and the first doped polysilicon layer 212 is far away from the silicon substrate 100;
[0058] or
[0059] The first doped layer includes a first intrinsic amorphous silicon layer and a first doped amorphous silicon layer stacked in sequence, wherein the first intrinsic amorphous silicon layer is close to the silicon substrate, and the first doped amorphous silicon layer is far away from the silicon substrate.
[0060] like Figures 2 to 4 As shown, in some embodiments, the second doped layer 220 includes a second silicon oxide layer 221 and a second doped polysilicon layer 222 stacked in sequence, wherein the second silicon oxide layer 221 is close to the silicon substrate 100, and the second doped polysilicon layer 222 is far away from the silicon substrate 100;
[0061] or
[0062] The second doped layer includes a second intrinsic amorphous silicon layer and a second doped amorphous silicon layer stacked in sequence, wherein the second intrinsic amorphous silicon layer is close to the silicon substrate, and the second doped amorphous silicon layer is far away from the silicon substrate.
[0063] In the present application, the doping type of the first doped polysilicon layer and the doping type of the second doped polysilicon layer are opposite, that is, when the first doped polysilicon layer is an N-type doped polysilicon layer, the second doped polysilicon layer is a P-type doped polysilicon layer; or, when the first doped polysilicon layer is a P-type doped polysilicon layer, the second doped polysilicon layer is an N-type doped polysilicon layer.
[0064] In the present application, the doping type of the first doped amorphous silicon layer and the doping type of the second doped amorphous silicon layer are opposite, that is, when the first doped amorphous silicon layer is an N-type doped amorphous silicon layer, the second doped amorphous silicon layer is a P-type doped amorphous silicon layer; or, when the first doped amorphous silicon layer is a P-type doped amorphous silicon layer, the second doped amorphous silicon layer is an N-type doped amorphous silicon layer.
[0065] In some embodiments, the surface of the first doped layer near the silicon substrate is not flush with the surface of the second doped layer near the silicon substrate. There is a height difference between the surface of the first doped layer near the silicon substrate and the surface of the second doped layer near the silicon substrate, and the height difference can be 0.1-5μm (for example, 0.1μm, 0.2μm, 0.3μm, 0.5μm, 0.8μm, 1μm, 2μm, 3μm, 4μm or 5μm). During the preparation of a back-contact solar cell, a fully covered initial first doped layer can be formed on the back of the silicon substrate, and then a portion of the initial first doped layer is removed, and the retained portion of the initial first doped layer forms the first doped layer; during the removal process, a portion of the thickness of the silicon substrate in the removed area can also be removed to ensure that no first doped layer remains in the removed area. Finally, a second doped layer is formed in the removed area, thereby effectively avoiding short circuits and reducing recombination losses.
[0066] In the embodiment of the present application, the surface of the silicon substrate may or may not have a velvet structure, which is not specifically limited here.
[0067] The following specific examples further illustrate the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and substance of the present invention, modifications or replacements made to the structure of the present invention are within the scope of the present invention.
[0068] Example 1
[0069] like Figure 1 and Figure 2 As shown, the back contact solar cell of Example 1 includes:
[0070] A silicon substrate 100, wherein the silicon substrate 100 includes a front surface and a back surface that are oppositely disposed;
[0071] The back side of the silicon substrate 100 has a doped region 200 and an undoped region 300 . The undoped region 300 is located in the peripheral area of the back side of the silicon substrate 100 . The width of the undoped region 300 is 1 cm.
[0072] The doping region 200 includes a first doping layer 210 and a second doping layer 220 that are alternately arranged. The doping type of the first doping layer 210 is opposite to that of the second doping layer 220.
[0073] The adjacent first doped layer 210 and the second doped layer 220 are in contact with each other only on their side surfaces; the first doped layer 210 includes a first silicon oxide layer 211 and a first doped polysilicon layer 212 stacked in sequence in a direction away from the substrate, and the second doped layer 220 includes a second silicon oxide layer 221 and a second doped polysilicon layer 222 stacked in sequence in a direction away from the substrate;
[0074] A dielectric layer 400 is located on the surface of the first doped layer 210 and the surface of the second doped layer 220; wherein the dielectric layer 400 includes a passivation layer 410 and an anti-reflection layer 420 stacked in sequence in a direction away from the substrate;
[0075] a first electrode 510 penetrating the dielectric layer 400 and contacting the first doping layer 210;
[0076] The second electrode 520 penetrates the dielectric layer 400 and contacts the second doping layer 220 .
[0077] Example 2
[0078] like Figure 3 As shown, the back contact solar cell of Example 2 includes:
[0079] A silicon substrate 100, wherein the silicon substrate 100 includes a front surface and a back surface that are oppositely disposed;
[0080] The back side of the silicon substrate 100 has a doped region 200 and an undoped region 300 . The undoped region 300 is located in the peripheral area of the back side of the silicon substrate 100 . The width of the undoped region 300 is 1.2 cm.
[0081] The doping region 200 includes a first doping layer 210 and a second doping layer 220 that are alternately arranged. The doping type of the first doping layer 210 is opposite to that of the second doping layer 220.
[0082] There is a 10 μm gap between adjacent first doped layers 210 and second doped layers 220; the first doped layer 210 includes a first silicon oxide layer 211 and a first doped polysilicon layer 212 stacked in a direction away from the substrate, and the second doped layer 220 includes a second silicon oxide layer 221 and a second doped polysilicon layer 222 stacked in a direction away from the substrate;
[0083] A dielectric layer 400 located on the surface of the first doped layer 210 and the surface of the second doped layer 220, wherein the dielectric layer 400 includes a passivation layer 410 and an anti-reflection layer 420 stacked in sequence in a direction away from the substrate;
[0084] a first electrode 510 penetrating the dielectric layer 400 and contacting the first doping layer 210;
[0085] The second electrode 520 penetrates the dielectric layer 400 and contacts the second doping layer 220 .
[0086] Example 3
[0087] like Figure 4 As shown, the back contact solar cell of Example 3 includes:
[0088] A silicon substrate 100, wherein the silicon substrate 100 includes a front surface and a back surface that are oppositely disposed;
[0089] The back side of the silicon substrate 100 has a doped region 200 and an undoped region 300 . The undoped region 300 is located in the peripheral region of the back side of the silicon substrate 100 . The width of the undoped region 300 is 0.8 cm.
[0090] The doping region 200 includes a first doping layer 210 and a second doping layer 220 that are alternately arranged. The doping type of the first doping layer 210 is opposite to that of the second doping layer 220.
[0091] Part of the second doped layer 220 is located above the adjacent first doped layer 210, and the first doped layer 210 is not completely covered; the first doped layer 210 includes a first silicon oxide layer 211 and a first doped polysilicon layer 212 stacked in sequence in a direction away from the substrate, and the second doped layer 220 includes a second silicon oxide layer 221 and a second doped polysilicon layer 222 stacked in sequence in a direction away from the substrate;
[0092] A dielectric layer 400 located on the surface of the first doped layer 210 and the surface of the second doped layer 220, wherein the dielectric layer 400 includes a passivation layer 410 and an anti-reflection layer 420 stacked in sequence in a direction away from the substrate;
[0093] a first electrode 510 penetrating the dielectric layer 400 and contacting the first doping layer 210;
[0094] The second electrode 520 penetrates the dielectric layer 400 and contacts the second doping layer 220 .
[0095] In order to more clearly illustrate the technical effects of the embodiments of the present application, the present application also provides a comparative example 1. The structure of the back-contact solar cell of comparative example 1 is similar to the structure of the back-contact solar cell of embodiment 1, and the only difference is that there is a doping layer in the peripheral area on the back side of the silicon substrate.
[0096] The back-contact solar cells of Examples 1 to 3 of the present application and Comparative Example 1 are prepared into corresponding solar cell modules, and the performance of the corresponding solar cell modules is tested to obtain the short-circuit current density Jsc, open-circuit voltage Voc, fill factor FF, and photoelectric conversion efficiency PCE of the corresponding solar cell modules. The test results are shown in Table 1.
[0097] Table 1
[0098]
[0099] It can be seen from the data in Table 1 that compared with the solar cell module of Comparative Example 1, the open circuit voltage and short circuit current density of the solar cell modules of Examples 1 to 3 of the present application are slightly improved, but the fill factor and photoelectric conversion efficiency are greatly improved. This is because Examples 1 to 3 of the present application do not have a doping layer in the peripheral area on the back side of the silicon substrate when preparing the back-contact solar cells, which reduces leakage at the edge of the battery and improves the long-term reliability of the battery.
[0100] In summary, in the embodiment of the present application, the back-contact solar cell has an undoped region located in the peripheral area of the back side of the silicon substrate, that is, the peripheral area of the back side of the silicon substrate does not have a doping layer. By removing the doping layer in the peripheral area of the back side of the silicon substrate to obtain the undoped region, the leakage phenomenon at the edge of the battery can be reduced, and at the same time, the performance degradation caused by edge leakage can be reduced, thereby improving the long-term reliability of the battery. In addition, since the peripheral area of the battery is usually not covered with a metal electrode, if there is a doping layer in the peripheral area of the back side of the silicon substrate, the carriers are easily recombined and cannot be collected. However, if there is no doping layer in the peripheral area of the back side of the silicon substrate, more carriers can be collected, thereby improving the photoelectric conversion rate.
[0101] The present invention also provides a photovoltaic module (not shown) comprising the back-contact solar cell described in any of the above embodiments. The photovoltaic module of the present invention can reduce the risk of electrical leakage and alleviate potential safety hazards.
[0102] The embodiments of the present application can provide a photovoltaic system, including the photovoltaic components in the above embodiments. The advantages of the above photovoltaic components are also possessed by the photovoltaic system, which will not be repeated here. The application field of the above photovoltaic system is wide, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water surface power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it is understandable that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to convert it into the alternating current required by the mains power grid and then connects to the mains power network to achieve solar power supply.
[0103] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting this application. The directional words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.
[0104] It should be noted that the terms "first", "second", "front", "back", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0105] It should also be noted that references to "one embodiment," "another embodiment," "an embodiment," etc., in this application refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also fall within the scope of this application.
[0106] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0107] It should also be noted that the above are only preferred embodiments of the present application and do not limit the scope of patent protection of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present application.
Claims
1. A back contact solar cell, characterized in that: include: A silicon substrate, the silicon substrate comprising a front surface and a back surface arranged opposite to each other; The back side of the silicon substrate has a doped region and an undoped region, and the undoped region is located in a peripheral region of the back side of the silicon substrate; The doping region includes a first doping layer and a second doping layer that are alternately arranged, and the doping type of the first doping layer is opposite to the doping type of the second doping layer.
2. The back contact solar cell according to claim 1, wherein: The width of the undoped region is 1×10 -6 -1.5cm.
3. The back contact solar cell according to claim 1, wherein: The back contact solar cell further comprises: a dielectric layer located on the first doped layer and the second doped layer; wherein the dielectric layer comprises a passivation layer and an anti-reflection layer stacked in sequence in a direction away from the substrate; a first electrode penetrating the dielectric layer and contacting the first doped layer; and A second electrode penetrates the dielectric layer and contacts the second doped layer.
4. The back contact solar cell according to claim 1, wherein: The second doping layer and the adjacent first doping layer are in contact with each other only at side surfaces.
5. The back contact solar cell according to claim 1, wherein: There is a gap between the second doping layer and the adjacent first doping layer, and the width of the gap is 0.1-500 μm.
6. The back contact solar cell according to claim 1, wherein: The second doping layer and the adjacent first doping layer are in contact with each other at side surfaces, and a portion of the second doping layer is located above the adjacent first doping layer and exposes at least a portion of the adjacent first doping layer.
7. The back contact solar cell according to claim 1, wherein: The first doped layer includes a first silicon oxide layer and a first doped polysilicon layer stacked in sequence, wherein the first silicon oxide layer is close to the silicon substrate, and the first doped polysilicon layer is far away from the silicon substrate; or The first doped layer includes a first intrinsic amorphous silicon layer and a first doped amorphous silicon layer stacked in sequence, wherein the first intrinsic amorphous silicon layer is close to the silicon substrate, and the first doped amorphous silicon layer is far away from the silicon substrate.
8. The back contact solar cell according to claim 1, wherein: The second doped layer includes a second silicon oxide layer and a second doped polysilicon layer stacked in sequence, wherein the second silicon oxide layer is close to the silicon substrate, and the second doped polysilicon layer is far away from the silicon substrate; or The second doped layer includes a second intrinsic amorphous silicon layer and a second doped amorphous silicon layer stacked in sequence, wherein the second intrinsic amorphous silicon layer is close to the silicon substrate, and the second doped amorphous silicon layer is far away from the silicon substrate.
9. The back contact solar cell according to claim 1, wherein: A surface of the first doped layer close to the silicon substrate is not flush with a surface of the second doped layer close to the silicon substrate.
10. A photovoltaic module, characterized in that: Comprising a back-contact solar cell as claimed in any one of claims 1 to 9.