Back contact solar cell, photovoltaic module and photovoltaic system

Abstract

The invention is applicable to the technical field of back contact solar cells, and provides a back contact solar cell, a photovoltaic module and a photovoltaic system.The back contact solar cell comprises a silicon substrate, a plurality of p-type doped regions and a plurality of n-type doped regions which are sequentially and alternately arranged on the back face of the silicon substrate in the first direction, and p-type fine grids electrically connected with the p-type doped regions; the n-type fine grids are electrically connected with the n-type doped regions, the isolation regions are arranged between the adjacent p-type doped regions and the n-type doped regions, and in the first direction, the ratio C1 of the width of the isolation regions to the width of the n-type doped regions is # imgabs0 #. And the photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of back-contact solar cells, and in particular relates to a back-contact solar cell, a photovoltaic module and a photovoltaic system. Background Art

[0002] Since the back-contact solar cell has no main grid line on the front, the positive and negative electrodes are arranged on the back of the battery, which reduces shading and effectively increases the short circuit of the battery, thereby improving the energy conversion efficiency of the solar cell and thus has broad application prospects.

[0003] The back contact cell forms an alternating arrangement of p-type doping area and n-type doping area on the backlight surface. Due to the different polarities of the p-type doping area and the n-type doping area, an isolation area needs to be set between the p-type doping area and the n-type doping area for isolation. A velvet structure is set in the isolation area to increase light reflection. However, due to the narrow width of the isolation area, the area of ​​the velvet structure inside the isolation area is small, the light reflectivity is low, and the photoelectric conversion efficiency of the cell is affected. Summary of the invention

[0004] The embodiment of the present invention provides a back-contact solar cell, aiming to solve the problem of low photoelectric conversion efficiency of existing back-contact solar cells.

[0005] The embodiment of the present invention is implemented as follows: a back contact solar cell, comprising:

[0006] A silicon substrate, wherein a plurality of p-type doping regions and a plurality of n-type doping regions are arranged alternately in sequence along a first direction on the back side of the substrate;

[0007] A p-type fine gate electrically connected to the p-type doped region;

[0008] An n-type fine gate electrically connected to the n-type doped region; and

[0009] An isolation region disposed between adjacent p-type doping regions and n-type doping regions;

[0010] In the first direction, the ratio of the width of the isolation region to the width of the n-type doping region is C1.

[0011] Furthermore, the ratio C1 of the width of the isolation region to the width of the n-type doping region is

[0012] Furthermore, the width of the isolation region is 200 micrometers to 300 micrometers.

[0013] Furthermore, the width of the n-type doping region is greater than or equal to the width of the p-type doping region.

[0014] Furthermore, a ratio of a width of the n-type doping region to a width of the p-type doping region is D1, and 1≤D1≤9.

[0015] Further, a ratio D1 of the width of the n-type doping region to the width of the p-type doping region is 1.5≤D1≤4.

[0016] Furthermore, the width of the p-type doping region is 100 micrometers to 900 micrometers.

[0017] Furthermore, the sum of the widths of the single p-type doping region, the single n-type doping region, and the single isolation region is 400 micrometers to 9.3 millimeters.

[0018] Furthermore, the sum of the widths of a single p-type doping region, a single n-type doping region, and a single isolation region is 450 micrometers to 4.8 millimeters.

[0019] Furthermore, the sheet resistance of the p-type doping region is greater than the sheet resistance of the n-type doping region.

[0020] Furthermore, the square resistance of the p-type doping region is 1.5 to 10 times that of the n-type doping region.

[0021] Furthermore, the back-contact solar cell also includes a passivation layer, which is arranged on the side of the n-type doped region and the p-type doped region facing away from the silicon substrate, and the passivation layer is provided with a first window and a second window, the p-type fine gate at least partially extends into the first window and contacts the p-type doped region, and the n-type fine gate at least partially extends into the second window and contacts the n-type doped region.

[0022] Further, the distance between the p-type doping region or the n-type doping region adjacent to the edge of the silicon substrate and the edge of the silicon substrate is smaller than the distance between the p-type doping region and the n-type doping region located in the middle region of the silicon substrate.

[0023] Furthermore, it also includes a main gate p-type doping region, the main gate p-type doping region is cross-connected with the p-type doping region, the n-type doping region is electrically isolated from the main gate p-type doping region, and the electrical isolation distance between the n-type doping region and the main gate p-type doping region is less than the width of the isolation region.

[0024] Further, the isolation region includes a first region, a second region and a trench;

[0025] The first region is adjacent to the p-type doping region, the second region is adjacent to the n-type doping region, and the trench is located between the first region and the second region.

[0026] Furthermore, the bottom of the groove is velvet.

[0027] Furthermore, the first area is a polished surface.

[0028] Furthermore, the second area is a polished surface.

[0029] Further, the first region is doped with a p-type dopant.

[0030] Further, the second region is doped with an n-type dopant.

[0031] Furthermore, the p-type doping region and the n-type doping region both include any one of polycrystalline silicon, amorphous silicon, microcrystalline silicon and single crystal silicon.

[0032] In a second aspect, the present application also provides a photovoltaic module, comprising the back-contact solar cell as described above.

[0033] In a third aspect, the present application also provides a photovoltaic system, comprising the photovoltaic assembly as described above.

[0034] Beneficial effects of the present application: The back-contact solar cell provided by the present application comprises a silicon substrate, wherein the back side of the silicon substrate is provided with a plurality of p-type doping regions and a plurality of n-type doping regions arranged alternately in sequence along a first direction; a p-type fine gate electrically connected to the p-type doping region; an n-type fine gate electrically connected to the n-type doping region; and an isolation region provided between adjacent p-type doping regions and n-type doping regions, wherein in the first direction, a ratio C1 of a width of the isolation region to a width of the n-type doping region is Through the above arrangement, the width of the isolation area is increased, thereby increasing the area of ​​the velvet structure in the isolation area, improving the light reflection efficiency, and improving the photoelectric conversion efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic structural diagram of an embodiment of a back contact solar cell provided by the present application;

[0036] Figure 2 is a schematic diagram of the distribution of doping regions of an embodiment of a back contact solar cell provided by the present application;

[0037] Figure 3 It is a partial structural schematic diagram of an embodiment of a back-contact solar cell provided in the present application.

[0038] Explanation of reference numerals: 100, silicon substrate; 110, p-type doped region; 120, n-type doped region; 130, isolation region; 200, passivation layer; 310, p-type fine gate; 320, n-type fine gate. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein 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 invention, and cannot be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 a limitation on the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference values ​​and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0045] The back-contact solar cell provided by the present application comprises a silicon substrate, wherein the back side of the silicon substrate is provided with a plurality of p-type doping regions and a plurality of n-type doping regions arranged alternately in sequence along a first direction; a p-type fine gate electrically connected to the p-type doping region; an n-type fine gate electrically connected to the n-type doping region; and an isolation region provided between adjacent p-type doping regions and n-type doping regions, wherein in the first direction, a ratio C1 of a width of the isolation region to a width of the n-type doping region is Through the above arrangement, the width of the isolation area is increased, thereby increasing the area of ​​the suede structure in the isolation area, improving the light reflection efficiency, and improving the photoelectric conversion efficiency of the solar cell.

[0046] Embodiment 1

[0047] like Figures 1 to 3 As shown, one embodiment of the present application provides a back contact solar cell, comprising:

[0048] A silicon substrate 100, wherein a plurality of p-type doping regions 110 and a plurality of n-type doping regions 120 are arranged alternately in sequence along a first direction on the back side of the silicon substrate 100;

[0049] A p-type fine gate 310 electrically connected to the p-type doping region 110;

[0050] An n-type fine gate 320 electrically connected to the n-type doping region 120; and

[0051] An isolation region 130 disposed between adjacent p-type doping regions 110 and n-type doping regions 120;

[0052] In the first direction, the ratio of the width of the isolation region 130 to the width of the n-type doping region 110 is

[0053] In practice, solar cells are also known as solar photovoltaics (abbreviated as PV), which are photoelectric semiconductor sheets that use sunlight to directly generate electricity. They are also called "solar chips" or "photovoltaics". As long as the solar cells are illuminated under certain illumination conditions, they can instantly output voltage and generate current in the presence of a circuit.

[0054] Back-contact solar cells refer to solar cells in which the electrode grid lines are located on the back of the cell, thereby reducing or eliminating the shading loss of the front grid lines and improving cell efficiency.

[0055] During implementation, the silicon substrate 100 can be an N-type silicon wafer or a P-type silicon wafer, wherein the N-type silicon wafer is obtained by adding pentavalent elements (such as phosphorus or arsenic) to the silicon raw material, and these pentavalent elements provide additional free electrons; the P-type silicon wafer is obtained by adding trivalent elements (such as boron or gallium) to the silicon raw material, and these trivalent elements control the diffusion of electron holes, which will not be elaborated.

[0056] The silicon substrate 100 has a front side and a back side, wherein the front side of the silicon substrate 100 corresponds to the light-receiving side of the solar cell, and similarly, the back side of the silicon substrate 100 corresponds to the backlight side of the solar cell.

[0057] Optionally, the silicon substrate 100 may be a single crystal silicon wafer, which is a single crystal formed by slowly cooling a silicon raw material after melting, and has a compact and orderly crystal structure and high conversion efficiency, stability and lifespan.

[0058] Alternatively, the silicon substrate 100 may be a polycrystalline silicon wafer, which is a form of single-substance silicon. When molten single-substance silicon solidifies under supercooling conditions, silicon atoms are arranged into many crystal nuclei in the form of diamond lattices. If these crystal nuclei grow into crystal grains with different crystal plane orientations, these crystal grains are combined to crystallize into polycrystalline silicon.

[0059] Optionally, the surface of the silicon substrate 100 can be a polished surface or a textured surface, without limitation. The textured surface is obtained by performing a texture process on the surface of the silicon substrate 100 to produce an uneven pyramid structure on the surface of the silicon substrate 100, and the light trapping effect of the uneven textured surface is utilized to increase the absorption of sunlight, reduce reflectivity, increase short-circuit current, and improve the photoelectric conversion efficiency of the solar cell.

[0060] Optionally, the texturing process includes but is not limited to acid texturing, alkali texturing, mechanical texturing, electrochemical texturing, reactive ion etching texturing, laser texturing and mask texturing, etc., which will not be elaborated herein.

[0061] The p-type doping region 110 is the positive electrode region of the solar cell, and the n-type doping region 120 is the negative electrode region of the solar cell. For example, taking an n-type silicon wafer as an example, a positive electrode region can be formed by doping a trivalent element such as boron on the n-type silicon wafer, and a negative electrode region can be formed by doping a pentavalent element such as phosphorus on the n-type silicon wafer, which will not be described in detail.

[0062] Optionally, the p-type doping region 110 and the n-type doping region 120 both include any one of polycrystalline silicon, amorphous silicon, microcrystalline silicon and single crystal silicon.

[0063] The p-type doping regions 110 and the n-type doping regions 120 are alternately distributed along the first direction on the back side of the silicon substrate 100. That is, there is an n-type doping region 120 between two p-type doping regions 110. Similarly, there is a p-type doping region 110 between two n-type doping regions 120. For ease of understanding, the present application takes the extension direction of the line segment L1 as the first direction. Figure 1 shown.

[0064] The p-type fine gate 310 and the n-type fine gate 320 are metal fine gates of the solar cell, wherein the p-type fine gate 310 is a positive metal fine gate for collecting current in the p-type doped region, and the n-type fine gate 320 is a negative metal fine gate for collecting current in the n-type doped region.

[0065] As a possible implementation, the solar cell is also provided with a main grid (not shown), including a positive main grid and a negative main grid, wherein the positive main grid is connected to multiple positive fine grids for collecting current collected by multiple positive fine grids, and the negative main grid is connected to multiple negative fine grids for collecting current collected by multiple negative fine grids.

[0066] Optionally, the main grid and the fine grid are arranged crosswise, preferably, the main grid and the fine grid are perpendicular, for example, when the main grid extends longitudinally, the fine grid extends transversely, which will not be described in detail.

[0067] Since the polarities of the p-type doping region 110 and the n-type doping region 120 are opposite, it is necessary to set electrical isolation between the p-type doping region 110 and the n-type doping region 120. For example, the present application achieves electrical isolation between the p-type doping region 110 and the n-type doping region 120 by setting an isolation region 130 between the p-type doping region 110 and the n-type doping region 120.

[0068] During implementation, the extension direction of the isolation region 130 is perpendicular or substantially perpendicular to the first direction. For example, when the first direction is horizontal, the extension direction of the isolation region 130 is vertical. Similarly, when the first direction is vertical, the extension direction of the isolation region 130 is horizontal.

[0069] A velvet structure is provided in the isolation area 130 , and the velvet structure is made by adopting the above-mentioned velvet making process. By utilizing the poor light trapping effect of the velvet structure in the isolation area 130 , the light reflection efficiency on the back of the solar cell is improved, thereby improving the photoelectric conversion efficiency of the solar cell.

[0070] In the first direction, the ratio of the width of the isolation region 130 to the width of the n-type doping region 120 is C1. For example, C1 is 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.9 or Any value from 0 to 3, without limitation.

[0071] Optionally, the width of the isolation region 130 is 200 microns to 300 microns, for example, the width of the isolation region 130 is 210 microns, 220 microns, 221 microns, 225 microns, 228 microns, 230 microns, 240 microns, 250 microns, 260 microns, 270 microns, 280 microns, 290 microns, 291 microns, 292 microns or any value between 200 microns and 300 microns, without limitation.

[0072] By increasing the width of the isolation region 130, the area of ​​the velvet structure in the isolation region 130 is increased, thereby improving the light reflection efficiency. On the other hand, when the width of the isolation region 130 increases, the widths of the p-type doping region 110 and the n-type doping region 120 are correspondingly reduced, resulting in a loss in the photoelectric conversion efficiency of the solar cell. In the present application, by designing the ratio of the width of the isolation region 130 to the width of the n-type doping region 120 to be within the above range, the improvement in the photoelectric conversion efficiency of the solar cell is greater than the loss efficiency, thereby improving the photoelectric conversion efficiency of the solar cell.

[0073] In some possible embodiments, the ratio C1 of the width of the isolation region 130 to the width of the n-type doping region 120 is: For example, C1 is 1 / 2, 3 / 4, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or Any value from 2 to 3, without limitation.

[0074] Through the above arrangement, the photoelectric conversion efficiency of the solar cell can be further improved.

[0075] In some optional embodiments, the width of the n-type doping region 120 is greater than or equal to the width of the p-type doping region 110 .

[0076] As a possible implementation, see Figure 1As shown, the n-type doping region 120 and the p-type doping region 110 are rectangular structures. Due to the high conductivity of the n-type doping region 120 compared to the p-type doping region 110, the lateral transmission capability of the n-type doping region 120 is stronger than that of the p-type doping region 110, and the transmission distance is larger. Therefore, by setting the width of the n-type doping region 120 to be greater than or equal to the width of the p-type doping region 110, according to the corresponding lateral transmission capabilities of the two, the carrier transmission distance is matched, and the current collection is balanced to obtain a smaller series resistance and a higher fill factor, thereby further improving the conversion efficiency.

[0077] As a possible implementation method, since the passivation characteristics of the highly doped n-type doping region 120 are better than those of the p-type doping region 110, the passivation contact area of ​​the n-type polysilicon material layer can be increased by reducing the width of the p-type doping region 110 and increasing the width of the n-type doping region 120, so that the overall comprehensive passivation level of the battery can be higher, the composite loss can be lower, and the conversion efficiency can be further improved.

[0078] In some optional embodiments, the ratio of the width of the n-type doping region 120 to the width of the p-type doping region 110 is D1, 1≤D1≤9. Exemplarily, D1 is 1.1, 1.5, 1.8, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9 or any value from 1 to 9, but is not limited thereto.

[0079] During implementation, if the ratio between the width of the n-type doping region 120 and the width of the p-type doping region 110 is too low, the improvement effect of the series resistance and the fill factor is poor. If the ratio between the width of the n-type doping region 120 and the width of the p-type doping region 110 is too high, the width of the p-type doping region 110 is too narrow, the short-circuit current is too low, and the conversion efficiency is affected.

[0080] Optionally, a ratio D1 of the width of the n-type doping region 120 to the width of the p-type doping region 110 is 1.5≤D1≤4. Exemplarily, D1 is 1.6, 1.7, 1.8, 2, 2.1, 2.2, 2.3, 2.5, 2.6, 2.8, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 or any value from 1.5 to 4, without specific limitation. Through the above settings, a smaller series resistance and a higher fill factor can be obtained.

[0081] In some optional embodiments, the width of the p-type doping region 110 is 100 micrometers to 900 micrometers. Exemplarily, the width of the p-type doping region 110 is 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, 150 micrometers, 180 micrometers, 200 micrometers, 210 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 550 micrometers, 600 micrometers, 650 micrometers, 700 micrometers, 750 micrometers, 800 micrometers, 850 micrometers, or any value between 100 micrometers and 900 micrometers, without specific limitation.

[0082] As a possible implementation manner, the width of the p-type doping region 110 is 200 microns to 500 microns, and the width of the p-type doping region 110 is 210 microns, 220 microns, 230 microns, 240 microns, 250 microns, 280 microns, 300 microns, 310 microns, 350 microns, 380 microns, 390 microns, 400 microns, 410 microns, 420 microns, 430 microns, 440 microns, 450 microns, 460 microns, 470 microns, 480 microns, 490 microns or any value between 200 microns and 500 microns, without specific limitation.

[0083] The present application reduces the lateral transport distance of carriers by designing the width of the p-type doping region 110 to be within the above range, thereby reducing the recombination loss during the transport process and improving the conversion efficiency.

[0084] Optionally, the sum of the widths of a single p-type doping region 110, a single n-type doping region 120, and a single isolation region 130 is 400 μm to 9.3 mm. For example, the sum of the widths of a single p-type doping region 110, a single n-type doping region 120, and a single isolation region 130 is 410 μm, 420 μm, 430 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 1000 μm, 1500 μm, 2000 μm, 2500 μm, 3000 μm, 3500 μm, 4000 μm, 5000 μm, 6000 μm, 7000 μm, 8000 μm, or any value between 400 μm and 9.3 mm without specific limitation.

[0085] The present application can maximize charge collection, shorten the lateral transport distance of carriers, reduce series resistance, improve fill factor, and effectively improve battery conversion efficiency by controlling the widths of the n-type doping region 120, the p-type doping region 110, and the isolation region 130.

[0086] Further, the sum of the widths of a single p-type doping region 110, a single n-type doping region 120, and a single isolation region 130 is 450 μm to 4.8 mm. For example, the sum of the widths of a single p-type doping region 110, a single n-type doping region 120, and a single isolation region 130 is 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, 600 μm, 700 μm, 1100 μm, 1300 μm, 2200 μm, 3600 μm, 4100 μm, 4200 μm, 4300 μm, 4400 μm, 4500 μm, 4600 μm, 4700 μm, or any value between 450 μm and 4.8 mm without specific limitation.

[0087] Through the above settings, the battery conversion efficiency is high and the preparation difficulty is relatively low, ensuring a higher production yield and better overall performance.

[0088] In some embodiments, the square resistance of the p-type doping region 110 is greater than the square resistance of the n-type doping region 120 .

[0089] Furthermore, the square resistance of the p-type doping region 110 is 1.5 times to 10 times the square resistance of the n-type doping region 120. For example, the square resistance of the p-type doping region 110 can be designed to be 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2 times, 2.2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.4 times, 5.1 times, 6.3 times, 7.8 times, 8.6 times, 9.1 times or any value from 1.5 times to 10 times the square resistance of the n-type doping region 120, without specific limitation.

[0090] Through the above arrangement, the square resistance of the n-type doping region 120 is low, and the lateral transport capability is stronger than that of the p-type doping region 110, and the width of the n-type doping region 120 is greater than that of the p-type doping region 110, thereby improving the series resistance and the fill factor while balancing the current collection, thereby improving the conversion efficiency.

[0091] In some optional embodiments, the back-contact solar cell provided in the present application further includes a passivation layer 200, which is disposed on the side of the n-type doping region 120 and the p-type doping region 110 facing away from the silicon substrate 100, and the passivation layer 200 is provided with a first window and a second window, the p-type fine gate 310 at least partially extends into the first window and contacts the p-type doping region 110, and the n-type fine gate 320 at least partially extends into the second window and contacts the n-type doping region 120.

[0092] The passivation layer 200 can effectively reduce the recombination of minority carriers and surface states on the back of the battery, which is beneficial to improving the photoelectric conversion efficiency of the battery. On the other hand, the passivation layer 200 can also improve the stability of the solar cell, reduce surface damage and oxidation reactions of the solar cell, and extend the service life of the solar cell.

[0093] In some possible embodiments, the passivation layer 200 includes silicon nitride, silicon oxynitride, titanium dioxide, aluminum oxide, ferric oxide, etc., without limitation.

[0094] As a possible implementation, the p-type fine gate 310 and the n-type fine gate 320 are made by printing silver paste and performing high-temperature sintering. The silver paste includes a glass body, and the glass body will corrode the passivation layer 200 during the high-temperature sintering process. That is, the first window and the second window on the passivation layer 200 can be generated by the glass body corroding the passivation layer 200, so that the prepared p-type fine gate 310 extends into the first window and contacts with the p-type doped region 110, and the prepared n-type fine gate 320 extends into the second window and contacts with the n-type doped region 120.

[0095] In some optional embodiments, since the p-type doping region 110 and the n-type doping region 120 are arranged alternately in sequence, the edge closest to the silicon substrate 100 may be the p-type doping region 110 or the n-type doping region 120. When the edge closest to the silicon substrate 100 is the p-type doping region 110, the distance between the p-type doping region 110 and the edge of the silicon substrate 100 is recorded as E1, and the distance between the p-type doping region 110 and the n-type doping region 120 located in the middle area of ​​the silicon substrate 100 is E2, and E1 is smaller than E2, such as Figure 2 shown.

[0096] Similarly, when the n-type doping region 120 is closest to the edge of the silicon substrate 100 , the distance between the n-type doping region 120 and the edge of the silicon substrate 100 is smaller than the distance between the p-type doping region 110 and the n-type doping region 120 located in the middle area of ​​the silicon substrate 100 .

[0097] As a possible implementation, the back-contact solar cell provided in the present application also includes a main gate p-type doping region (not shown in the figure), the main gate p-type doping region is cross-connected with the p-type doping region 110, the n-type doping region 120 is electrically isolated from the main gate p-type doping region, and the electrical isolation distance between the n-type doping region 120 and the main gate p-type doping region is less than the width of the isolation region 130.

[0098] In some possible embodiments, the isolation region 130 includes a first region 131 , a second region 131 , and a trench 133 ;

[0099] The first region 131 is adjacent to the p-type doping region 110, the second region 132 is adjacent to the n-type doping region 120, and the trench 133 is located between the first region 131 and the second region 132. Figure 3 shown.

[0100] Optionally, the bottom of the groove 133 is a velvet surface. In practice, the bottom of the groove 133 can be made into a velvet surface by the above-mentioned velvet making process, which will not be described in detail. By designing the bottom of the groove 133 as a velvet surface, the reflectivity of the light in the groove 133 can be effectively improved, thereby improving the photoelectric conversion efficiency of the solar cell.

[0101] In some possible embodiments, the first region 131 is a polished surface, and optionally, the second region 132 is also a polished surface.

[0102] As a possible implementation, the first region 131 is doped with a p-type dopant, and similarly, the second region 132 is doped with an n-type dopant, wherein the p-type dopant is the above-mentioned trivalent element, such as boron or gallium, and the n-type dopant is the above-mentioned pentavalent element, such as phosphorus or arsenic. Through the above configuration, the power and power generation of the solar cell can be improved.

[0103] Embodiment 2

[0104] In some optional embodiments, the present application provides a photovoltaic module, comprising the back-contact solar cell as described above.

[0105] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the photovoltaic assembly described above can refer to the corresponding structure and implementation principle in the aforementioned embodiment 1, and will not be repeated here.

[0106] The back-contact solar cell provided in the present application includes a silicon substrate 100, wherein the back side of the silicon substrate 100 is provided with a plurality of p-type doping regions 110 and a plurality of n-type doping regions 120 arranged alternately in sequence along a first direction, a p-type fine gate 310 electrically connected to the p-type doping region 110; an n-type fine gate 320 electrically connected to the n-type doping region 120, and an isolation region 130 arranged between adjacent p-type doping regions 110 and n-type doping regions 120, wherein in the first direction, a ratio C1 of a width of the isolation region 130 to a width of the n-type doping region 120 is Through the above arrangement, the width of the isolation region 130 is increased, thereby increasing the area of ​​the suede structure in the isolation region 130, improving the light reflection efficiency, and improving the photoelectric conversion efficiency of the solar cell.

[0107] Embodiment 3

[0108] In some optional embodiments, the present application provides a photovoltaic system, including the photovoltaic component as described above.

[0109] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the structure and implementation principle of the photovoltaic system described above can refer to the corresponding structure and implementation principle in the aforementioned embodiments one and two, and will not be repeated here.

[0110] The back-contact solar cell provided in the present application includes a silicon substrate 100, wherein the back side of the silicon substrate 100 is provided with a plurality of p-type doping regions 110 and a plurality of n-type doping regions 120 arranged alternately in sequence along a first direction, a p-type fine gate 310 electrically connected to the p-type doping region 110, an n-type fine gate 32 electrically connected to the n-type doping region 120, and an isolation region 130 arranged between adjacent p-type doping regions 110 and n-type doping regions 120, wherein in the first direction, a ratio C1 of a width of the isolation region 130 to a width of the n-type doping region 120 is Through the above arrangement, the width of the isolation region 130 is increased, thereby increasing the area of ​​the suede structure in the isolation region 130, improving the light reflection efficiency, and improving the photoelectric conversion efficiency of the solar cell.

[0111] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A back contact solar cell, characterized in that: include: A silicon substrate, wherein a plurality of p-type doping regions and a plurality of n-type doping regions are arranged alternately in sequence along a first direction on the back side of the silicon substrate; A p-type fine gate electrically connected to the p-type doped region; An n-type fine gate electrically connected to the n-type doped region; as well as An isolation region disposed between adjacent p-type doping regions and adjacent n-type doping regions; In the first direction, the ratio of the width of the isolation region to the width of the n-type doping region is C1, 2. The back contact solar cell according to claim 1, characterized in that The ratio C1 of the width of the isolation region to the width of the n-type doping region is 3. The back contact solar cell according to claim 1 or 2, characterized in that: The width of the isolation region is 200 micrometers to 300 micrometers.

4. The back contact solar cell according to claim 1, characterized in that: The width of the n-type doping region is greater than or equal to the width of the p-type doping region.

5. The back contact solar cell according to claim 4, characterized in that The ratio of the width of the n-type doping region to the width of the p-type doping region is D1, 1≤D1≤9.

6. The back contact solar cell according to claim 5, characterized in that A ratio D1 of the width of the n-type doping region to the width of the p-type doping region is 1.5≤D1≤4.

7. The back contact solar cell according to claim 2, characterized in that: The width of the p-type doping region is 100 micrometers to 900 micrometers.

8. The back contact solar cell according to claim 1, characterized in that: The sum of the widths of a single p-type doping region, a single n-type doping region, and a single isolation region is 400 micrometers to 9.3 millimeters.

9. The back contact solar cell according to claim 8, characterized in that The sum of the widths of a single p-type doping region, a single n-type doping region, and a single isolation region is 450 micrometers to 4.8 millimeters.

10. The back contact solar cell according to claim 1, wherein: The sheet resistance of the p-type doping region is greater than the sheet resistance of the n-type doping region.

11. The back contact solar cell according to claim 10, characterized in that: The square resistance of the p-type doping region is 1.5 to 10 times that of the n-type doping region.

12. The back contact solar cell according to claim 1, wherein: The back-contact solar cell also includes a passivation layer, which is arranged on the side of the n-type doping region and the p-type doping region facing away from the silicon substrate, and the passivation layer is provided with a first window and a second window, the p-type fine gate at least partially extends into the first window and contacts the p-type doping region, and the n-type fine gate at least partially extends into the second window and contacts the n-type doping region.

13. The back contact solar cell according to claim 1, wherein: The distance between the p-type doping region or the n-type doping region adjacent to the edge of the silicon substrate and the edge of the silicon substrate is smaller than the distance between the p-type doping region and the n-type doping region located in the middle area of ​​the silicon substrate.

14. The back contact solar cell according to claim 1, wherein: It also includes a main gate p-type doping region, which is cross-connected with the p-type doping region, the n-type doping region is electrically isolated from the main gate p-type doping region, and the electrical isolation distance between the n-type doping region and the main gate p-type doping region is less than the width of the isolation region.

15. The back contact solar cell according to claim 1, wherein: The isolation region includes a first region, a second region and a trench; The first region is adjacent to the p-type doping region, the second region is adjacent to the n-type doping region, and the trench is located between the first region and the second region.

16. The back contact solar cell according to claim 15, characterized in that The bottom of the groove is velvet.

17. The back contact solar cell according to claim 15 or 16, characterized in that: The first area is a polished surface.

18. The back contact solar cell according to claim 15 or 16, characterized in that: The second area is a polished surface.

19. The back contact solar cell according to claim 17, wherein: The first region is doped with a p-type dopant.

20. The back contact solar cell according to claim 18, wherein: The second region is doped with an n-type dopant.

21. The back contact solar cell according to claim 1, wherein: The p-type doping region and the n-type doping region both include any one of polycrystalline silicon, amorphous silicon, microcrystalline silicon and single crystal silicon.

22. A photovoltaic module, characterized in that: A back-contact solar cell comprising the method of any one of claims 1 to 21.

23. A photovoltaic system, characterized in that: Comprising the photovoltaic module as claimed in claim 22.

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