Solar cell and photovoltaic module

Abstract

The invention provides a solar cell and a photovoltaic module, and relates to the technical field of photovoltaics. The solar cell includes: a silicon substrate; the silicon substrate comprises a light facing surface and a backlight surface which are opposite; the N-type doped layer is located on the back of the silicon substrate; the N-type collector grid lines are distributed in parallel at intervals and located on the side, away from the silicon substrate, of the N-type doping layer; the distance between every two adjacent N-type collector grid lines is smaller than 1.391 mm. In the invention, the distance between the adjacent N-type collector grid lines is smaller than 1.391 mm, so that factors such as parasitic absorption, recombination current of a metal region, transverse resistance and the like can reach better balance, the performance of the solar cell is better, and the photoelectric conversion efficiency is higher.

Description

[0001] This application is a divisional application. The application date of the parent application is June 11, 2024. The application number is 202410752794.0. The name of the invention is: A solar cell and a photovoltaic module. Technical Field

[0002] The invention relates to the field of photovoltaic technology, in particular to a solar cell and a photovoltaic module. Background Art

[0003] Solar cells can convert solar energy into electrical energy. They utilize clean energy and therefore have broad application prospects.

[0004] The various factors in a solar cell need to cooperate with each other to achieve the function of converting solar energy into electrical energy. However, in existing solar cells, the cooperation between the various factors is not appropriate, resulting in poor performance of the solar cell. Summary of the invention

[0005] The present invention provides a solar cell and a photovoltaic module, aiming to solve the problem that the performance of the solar cell is poor due to inappropriate coordination between different factors in the existing solar cell.

[0006] A first aspect of the present invention provides a solar cell, comprising:

[0007] A silicon substrate; the silicon substrate comprises a light-facing surface and a backlight surface opposite to each other;

[0008] An N-type doped layer is located on the backlight surface of the silicon substrate; the thickness of the N-type doped layer is 100 nm to 140 nm;

[0009] A plurality of N-type collector gate lines that are spaced apart and distributed in parallel are located on a side of the N-type doped layer away from the silicon substrate, and a spacing between adjacent N-type collector gate lines is less than 1.391 mm;

[0010] A P-type doped layer, located on the light-facing surface of the silicon substrate;

[0011] A plurality of P-type collector gate lines that are spaced apart and distributed in parallel are located on a side of the P-type doped layer away from the silicon substrate, and the spacing between adjacent P-type collector gate lines is less than or equal to the spacing between adjacent N-type collector gate lines.

[0012] In the present application, the N-type doped layer is located on the backlight surface of the silicon substrate, and the thickness of the N-type doped layer is 100nm to 140nm, which is more favorable to the square resistance, parasitic absorption, composite current in the passivation zone, composite current in the metal zone and other factors of the N-type doped layer, so that the performance of the solar cell is better and the photoelectric conversion efficiency is higher. At the same time, the spacing between adjacent N-type collector grid lines is less than 1.391mm, so that factors such as parasitic absorption, composite current in the metal zone and lateral resistance can achieve a better balance, so that the performance of the solar cell is better and the photoelectric conversion efficiency is higher. In addition, the spacing between adjacent P-type collector grid lines is less than or equal to the spacing between adjacent N-type collector grid lines. Specifically, because it is not easy for the P-type doped layer to obtain a higher doping concentration, the spacing between adjacent P-type collector grid lines can be smaller, which can further improve the efficiency of the solar cell.

[0013] A second aspect of the present invention provides a solar cell, comprising:

[0014] A silicon substrate; the silicon substrate comprises a light-facing surface and a backlight surface opposite to each other;

[0015] The N-type doped layer is located on the backlight surface of the silicon substrate; the thickness of the N-type doped layer is 100nm to 140nm; the doping concentration of the N-type doped layer is 3E20 cm -3 to 7E20 cm -3 ;

[0016] A plurality of N-type collector gate lines that are spaced apart and distributed in parallel are located on a side of the N-type doped layer away from the silicon substrate, and a spacing between adjacent N-type collector gate lines is less than 1.391 mm.

[0017] In the present application, the N-type doping layer is located on the backlight surface of the silicon substrate, and the thickness of the N-type doping layer is 100nm to 140nm, which is more favorable to the square resistance, parasitic absorption, composite current in the passivation zone, composite current in the metal zone and other factors of the N-type doping layer, so that the performance of the solar cell is better and the photoelectric conversion efficiency is higher. At the same time, the spacing between adjacent N-type collector grid lines is less than 1.391mm, so that factors such as parasitic absorption, composite current in the metal zone and lateral resistance can achieve a better balance, so that the performance of the solar cell is better and the photoelectric conversion efficiency is higher. In addition, the doping concentration of the N-type doping layer is an important factor affecting the square resistance of the N-type doping layer. In the present application, the doping concentration of the N-type doping layer is limited to the above-mentioned more suitable range, so that the square resistance of the N-type doping layer can be located in a suitable range, so that factors such as parasitic absorption, composite current in the metal zone and lateral resistance can achieve a better balance, so that the performance of the solar cell is better and the photoelectric conversion efficiency is higher.

[0018] A third aspect of the present invention provides a solar cell, comprising:

[0019] A silicon substrate; the silicon substrate includes an opposite light-facing surface and a backlight surface;

[0020] The backlight surface includes: a first conductive region and a second conductive region that are spaced apart;

[0021] An N-type doping layer is located on the first conductive region; the sheet resistance of the N-type doping layer is greater than 14 ohms per square and less than or equal to 40 ohms per square;

[0022] A P-type doping layer is located on the second conductive region; the sheet resistance of the P-type doping layer is from 20 ohms per square to 166 ohms per square;

[0023] A plurality of N-type collector grid lines that are spaced apart and parallel are located on the side of the N-type doping layer away from the silicon substrate, and the distance between adjacent N-type collector grid lines is less than 1.391 mm.

[0024] In this application, both the N-type doping layer and the P-type doping layer are located on the backlight surface of the silicon substrate. The sheet resistance of the N-type doping layer is from 14 ohms per square to 40 ohms per square, and the distance between adjacent N-type collector grid lines is less than 1.391 mm. The sheet resistance of the N-type doping layer and the distance between adjacent N-type collector grid lines are respectively within the above ranges, so that factors such as parasitic absorption, recombination current in the metal region, and lateral resistance can reach a better balance, making the performance of the solar cell better and the photoelectric conversion efficiency higher. The sheet resistance of the P-type doping layer within this range is beneficial to improving the efficiency of the solar cell.

[0025] In the fourth aspect of the present invention, a photovoltaic module is provided, including: a plurality of back-contact solar cells according to any one of the preceding claims. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Shows a partial structural schematic diagram of a solar cell in an embodiment of the present invention;

[0028] Figure 2 Shows a graph of the influence of the sheet resistance of an N-type doping layer and the distance between adjacent N-type collector grid lines on the efficiency of a solar cell in an embodiment of the present invention;

[0029] Figure 3Shows a fitting curve graph of the sheet resistance of an N-type doping layer and the spacing between adjacent N-type collector grid lines in an embodiment of the present invention;

[0030] Figure 4 Shows a graph of the influence of the thickness of an N-type doping layer and the spacing between adjacent N-type collector grid lines on the efficiency of a solar cell in an embodiment of the present invention;

[0031] Figure 5 Shows a graph of the influence of the sheet resistance of a P-type doping layer and the spacing between adjacent P-type collector grid lines on the efficiency of a solar cell in an embodiment of the present invention.

[0032] Explanation of the drawing reference numerals:

[0033] 1 - N-type doping layer, 2 - N-type collector grid line. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0035] This application provides at least three types of solar cells. Subsequently, the above several types of solar cells will be explained mainly from the first aspect, the second aspect, and the third aspect. Among them, in the solar cell of the first aspect, the N-type doping layer is located on the backlight side of the silicon substrate, and the P-type doping layer is located on the light-facing side of the silicon substrate, which is a double-sided cell. The specific type of the solar cell of the first aspect is not limited. For example, the solar cell of the first aspect can be a double-sided TOPCON (tunnel oxide passivated contact) cell. In the solar cell of the second aspect, the N-type doping layer is located on the backlight side of the silicon substrate, and the P-type doping layer can be located on the light-facing side or the backlight side of the silicon substrate. This solar cell can be a double-sided cell or a back-contact solar cell. The specific type of the solar cell of the second aspect is not limited. For example, the solar cell of the second aspect can be a TOPCON cell. In the solar cell of the third aspect, both the N-type doping layer and the P-type doping layer are located on the backlight side of the silicon substrate, which is a back-contact solar cell. The specific type of the solar cell of the third aspect is not limited. For example, the solar cell of the third aspect can be a TBC (TOPCON and IBC combination) cell.

[0036] It should be noted that, to avoid repetition, in the solar cells of the second aspect and the third aspect, only the differences from the solar cells of the first aspect are mainly described, and the same or related parts as the solar cells of the foregoing first aspect can be referred to the relevant descriptions of the foregoing first aspect.

[0037] The solar cell of the first aspect includes: a silicon substrate, an N-type doping layer, N-type collector grid lines, a P-type doping layer, and P-type collector grid lines. The doping type, crystal type, etc. of the silicon substrate are not specifically limited. For example, the silicon substrate can be an N-type doped single crystal silicon, etc. The silicon substrate includes an opposite light-facing surface and a backlight surface. During the normal operation of the solar cell, the surface mainly receiving light is the light-facing surface, and the backlight surface is opposite to the light-facing surface.

[0038] The N-type doping layer is located on the backlight surface of the silicon substrate. The N-type doping layer and the foregoing silicon substrate can form a high-low junction or a PN junction, which is not specifically limited. The N-type doping layer can be located on the entire backlight surface of the silicon substrate. In some embodiments, the N-type doping layer can be only located on a partial area of the backlight surface of the silicon substrate. For example, the N-type doping layer can be only located on a partial area of the backlight surface of the silicon substrate in the form of a finger structure. The thickness of the N-type doping layer is 100 nm (nanometers) to 140 nm. The thickness of the N-type doping layer is more appropriate, which is more beneficial to several factors such as the sheet resistance of the N-type doping layer, parasitic absorption, recombination current in the passivation region, and recombination current in the metal region, making the performance of the solar cell better and the photoelectric conversion efficiency higher. More specifically, referring to Figure 1 , the side wall of the N-type collector grid line 2 is in contact with the N-type doping layer 1. The larger the height h and the bottom side length a of the N-type collector grid line 2, the larger the side wall area of the N-type collector grid line 2, and the larger the recombination current in the metal region. Assuming that the recombination rate of the side wall of the N-type collector grid line 2 is 10 7 cm / s, estimate the recombination current in the metal region and the recombination current in the passivation region are weighted and averaged according to the area ratio to obtain the macroscopic recombination current in the metal region. When the height h of the N-type collector grid line 2 is fixed, change the thickness of the N-type doping layer 1 to t, and estimate the recombination current in the metal region. Figure 4 It is a graph showing the influence of t (the thickness of the N-type doping layer) and d (the distance between adjacent N-type collector grid lines) on the efficiency of the solar cell. Figure 4 In it, the order of each curve from bottom to top corresponds to the distances between adjacent N-type collector grid lines being: 1.964 mm, 1.78 mm, 1.628 mm, 1.5 mm, 1.391 mm, 1.296 mm, 1.213 mm, 1.141 mm, 1.076 mm, 1.019 mm, 0.977 mm, 0.967 mm, 0.92 mm, 0.878 mm, 0.839 mm, a total of 15 distances. Figure 4Among them, a point includes data on the left and data on the right. The data on the left in this point is the thickness of the N-type doping layer, and the data on the right is the efficiency of the solar cell corresponding to this thickness. According to Figure 4 , it can be obtained that when the thickness of the N-type doping layer is 100 nm to 140 nm, especially about 120 nm, for the spacing between the above 15 adjacent N-type collector grid lines, the efficiency of the solar cell basically reaches the maximum. At the same time, when the thickness of the N-type doping layer is less than 100 nm, the efficiency of the solar cell increases with the increase of the thickness of the N-type doping layer. And when the thickness of the N-type doping layer is greater than 140 nm, the efficiency of the solar cell remains stable or tends to decrease with the increase of the thickness of the N-type doping layer. Moreover, when the thickness of the N-type doping layer is 100 nm to 140 nm, the recombination current in the metal region estimated by the foregoing method is also small. Therefore, in the present application, the thickness of the N-type doping layer is 100 nm to 140 nm, which is more favorable for several factors such as the sheet resistance of the N-type doping layer, parasitic absorption, recombination current in the passivation region, and recombination current in the metal region, making the performance of the solar cell better and the photoelectric conversion efficiency higher.

[0039] For example, the thickness of the N-type doping layer can be 100 nm, 103.2 nm, 105 nm, 109 nm, 110 nm, 115 nm, 118.3 nm, 120 nm, 125 nm, 128 nm, 130 nm, 132.3 nm, 135 nm, 137.9 nm, 140 nm.

[0040] A plurality of N-type collector grid lines that are spaced apart and distributed in parallel are located on the side of the N-type doping layer facing away from the silicon substrate, and the N-type collector grid lines are used to collect carriers. As Figure 1 In, 1 is the schematic diagram of the N-type doping layer, and 2 is the schematic diagram of the N-type collector grid line. The number of N-type collector grid lines 2 in the solar cell is not specifically limited. Figure 1 In, the silicon substrate is located on the upper side of the N-type doping layer, and the N-type collector grid line 2 is inserted into the N-type doping layer 1. The spacing between adjacent N-type collector grid lines 2 is less than 1.391 mm (millimeter). The spacing between adjacent N-type collector grid lines refers to the spacing between two adjacent N-type collector grid lines 2 arranged closely. The spacing between adjacent N-type collector grid lines is less than 1.391 mm. When the spacing between adjacent N-type collector grid lines is within the above range, factors such as parasitic absorption, recombination current in the metal region, and transverse resistance can reach a better balance, making the performance of the solar cell better and the photoelectric conversion efficiency higher.

[0041] Specifically, Figure 2 is a curve graph showing the influence of the sheet resistance of the N-type doping layer and the spacing between adjacent N-type collector grid lines on the efficiency of the solar cell. For example, refer to the following Figure 2, Figure 2 In which, the abscissa is the sheet resistance of the N-type doping layer, such as the N-type doped polysilicon layer or the phosphorus-doped polysilicon layer, Figure 2 and the ordinate in is the efficiency of the solar cell. Figure 2 In , the order of each curve from bottom to top corresponds to the distances between adjacent N-type collector grid lines as follows: 1.964mm, 1.78mm, 1.628mm, 1.5mm, 1.391mm, 1.296mm, 1.213mm, 1.141mm, 1.076mm, 1.019mm, 0.977mm, 0.967mm, 0.92mm, 0.878mm, 0.839mm, a total of 15 distances. Figure 2 In , solar cells with an efficiency greater than or equal to 26%, such as 26.0% to 26.5%, are selected as the solar cells with relatively high efficiency, that is, Figure 2 the part enclosed by the dashed square in , and the efficiencies of the solar cells corresponding to the part below the dashed square are all less than 26%. It can be obtained from Figure 2 that among the above 15 distances between adjacent N-type collector grid lines, the distances between adjacent N-type collector grid lines greater than or equal to 1.391mm, namely 1.964mm, 1.78mm, 1.628mm, 1.5mm, 1.391mm, these 5 distances, and / or, the efficiencies of the solar cells corresponding to the sheet resistance of the N-type doping layer less than 14 ohms / square or greater than 40 ohms / square are all less than 26%. This shows that when the distance between adjacent N-type collector grid lines is greater than or equal to 1.391mm, and / or, the sheet resistance of the N-type doping layer is less than 14 ohms / square or greater than 40 ohms / square, the solar cell cannot obtain better efficiency. Therefore, in this application, the distance between adjacent N-type collector grid lines less than 1.391mm is selected, and the sheet resistance of the N-type doping layer is 14 ohms / square to 40 ohms / square, which is beneficial to improving the efficiency of the solar cell. For example, Figure 2 in this application, when the distance between adjacent N-type collector grid lines less than 1.391mm is selected, and the sheet resistance of the N-type doping layer is 14 ohms / square to 40 ohms / square, the efficiency of the solar cell is greater than or equal to 26%, and even reaches 26.5% and above.

[0042] For example, the distance between adjacent N-type collector grid lines can be 1.296mm, 1.213mm, 1.141mm, 1.076mm, 1.019mm, 1mm, 0.977mm, 0.967mm, 0.92mm, 0.878mm, 0.839mm, 0.8mm.

[0043] The P-type doped layer is located on the light-facing surface of the silicon substrate, that is, the N-type doped layer of the solar cell of the first aspect is located on the backlight surface of the silicon substrate, and the P-type doped layer is located on the light-facing surface of the silicon substrate. The solar cell is a bifacial cell, and other structures of the solar cell are not limited. Here, the P-type doped layer forms a PN junction or a high-low junction with the silicon substrate. The P-type doped layer can cover the entire light-facing surface or part of the light-facing surface of the silicon substrate, and there is no limitation on this. For example, the silicon substrate can be N-type doped single crystal silicon, the N-type doped layer is an N-type doped polycrystalline silicon layer, the N-type doped polycrystalline silicon layer is located on the backlight surface of the silicon substrate, and the P-type doped layer is a P-type doped polycrystalline silicon layer, and the P-type doped polycrystalline silicon layer is located on the light-facing surface of the silicon substrate. A first tunneling oxide layer is also provided between the N-type doped layer and the silicon substrate. The solar cell may also include anti-reflection layers and other film layers, and there is no specific limitation on the other film layers included therein.

[0044] A plurality of P-type collector grid lines that are spaced apart and distributed in parallel are located on the side of the P-type doped layer away from the silicon substrate, and the P-type collector grid lines are used to collect carriers. The spacing between adjacent P-type collector grid lines is less than or equal to the spacing between adjacent N-type collector grid lines. Specifically, because it is not easy for the P-type doped layer to obtain a higher doping concentration, the spacing between adjacent P-type collector grid lines can be smaller, which can further improve the efficiency of the solar cell. In the case where the spacing between adjacent P-type collector grid lines is less than the spacing between adjacent N-type collector grid lines, the difference between the two is not specifically limited. It should be noted that there is no specific limitation on the material of the P-type collector grid line, and there is no specific limitation on whether the material of the P-type collector grid line is the same as that of the N-type collector grid line. For example, the P-type collector grid line can be a silver collector grid line, etc.

[0045] In some embodiments, from Figure 5 It can be concluded that when the spacing between adjacent P-type collector grid lines is less than 1.391 mm, the various performances of the solar cell are relatively good, and the efficiency of the solar cell is relatively high, reaching 26% or more. For example, the spacing between adjacent P-type collector grid lines can be: 1.296 mm, 1.213 mm, 1.141 mm, 1.076 mm, 1.019 mm, 0.99 mm, 0.977 mm, 0.967 mm, 0.92 mm, 0.878 mm, 0.839 mm.

[0046] In some embodiments, the P-type doped layer is a P-type polysilicon doped layer and / or a P-type doped microcrystalline silicon layer, and the P-type doped layer is flexible and diverse.

[0047] In some embodiments, the N-type doped layer includes: an N-type doped polysilicon layer and / or an N-type doped microcrystalline silicon layer.

[0048] In some embodiments, the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm.

[0049] In some embodiments, the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm. Specifically, when the spacing between adjacent N-type collector grid lines is from 1.019 mm to 1.296 mm, the efficiency of the solar cell is greater than or equal to 26.0%, and the rate of increase in efficiency is the fastest. When the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm, the efficiency of the solar cell is greater than or equal to 26.0%, and the rate of decrease in efficiency is the slowest. Therefore, in this application, the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm. By further optimizing the spacing between adjacent N-type collector grid lines, the efficiency of the solar cell is further improved. It should be noted that the material of the N-type collector grid line is not specifically limited. For example, the N-type collector grid line can be a silver collector grid line.

[0050] For example, the spacing between adjacent N-type collector grid lines can be 0.977 mm, 0.971 mm, 0.967 mm, 0.9 mm, 0.92 mm, 0.913 mm, 0.878 mm, 0.8 mm, 0.839 mm.

[0051] In some embodiments, the doping concentration of the N-type doping layer is 3E20 cm -3 to 7E20 cm -3 Specifically, the doping concentration of the N-type doping layer is an important factor affecting the sheet resistance of the N-type doping layer. In this application, the doping concentration of the N-type doping layer is limited within the above suitable range, so that the sheet resistance of the N-type doping layer is within a suitable range, enabling factors such as parasitic absorption, recombination current in the metal region, and lateral resistance to reach a better balance, resulting in better performance of the solar cell and higher photoelectric conversion efficiency.

[0052] For example, the doping concentration of the N-type doping layer can be 3E20 cm -3 、3.2E20 cm -3 、3.5E20 cm -3 、4E20cm -3 、4.3E20 cm -3 、4.7E20 cm -3 、4.21E20 cm -3 、5E20 cm -3 、5.2E20 cm -3 、5.5E20 cm -3 、6E20cm -3 、6.3E20 cm -3 、7E20 cm-3 。

[0053] In some embodiments, the sheet resistance of the N-type doped layer is greater than 20 ohms per square and less than or equal to 40 ohms per square. The sheet resistance of the N-type doped layer refers to: for a portion of the N-type doped layer with a length of l, a width of w, and a height of d (i.e., the thickness of the N-type doped layer), at this time L = l and S = w × d for this portion, so R sh = ρ×l / (w×d) = (ρ / d)×(l / w). Let l = w, then R sh = (ρ / d), where ρ is the resistivity of the N-type doped layer, and the R at this time sh is the sheet resistance of the N-type doped layer. Here, a square refers to a region in the N-type doped layer where the length and width are equal and the thickness can vary. When the length and width of the square are equal, the size of the length and width has basically no effect on the sheet resistance. For example, when the length and width of the square are equal, the length and width can both be 1 cm or 1 m, and their corresponding sheet resistances are equal, but the sheet resistance decreases as the thickness of the square increases.

[0054] Specifically, referring to Figure 2 , the sheet resistance of the N-type doped layer is 20 ohms per square, which is roughly the sheet resistance of the N-type doped layer corresponding to the inflection point of the efficiency in the part where the efficiency is greater than or equal to 26%. More specifically, when the sheet resistance of the N-type doped layer is greater than 20 ohms per square and less than or equal to 40 ohms per square, and the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm, the efficiency of the solar cell is greater than or equal to 26.0%, and the rate of efficiency decline is the slowest. Therefore, in this application, the sheet resistance of the N-type doped layer is greater than 20 ohms per square and less than or equal to 40 ohms per square, and the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm. Through further combined optimization of the sheet resistance of the N-type doped layer and the spacing between adjacent N-type collector grid lines, the efficiency of the solar cell is further improved. It should be noted that the material of the N-type collector grid line is not specifically limited. For example, the N-type collector grid line can be a silver collector grid line.

[0055] For example, the sheet resistance of the N-type doped layer can be 20.3 ohms / square, 20.7 ohms / square, 21 ohms / square, 21.3 ohms / square, 22 ohms / square, 22.5 ohms / square, 23 ohms / square, 23.5 ohms / square, 24 ohms / square, 24.5 ohms / square, 25 ohms / square, 25.6 ohms / square, 27 ohms / square, 28 ohms / square, 29.6 ohms / square, 30 ohms / square, 31.6 ohms / square, 36.2 ohms / square, 38.56 ohms / square, 40 ohms / square, and the pitch between adjacent N-type collector grid lines can be 0.977 mm, 0.971 mm, 0.967 mm, 0.9 mm, 0.92 mm, 0.913 mm, 0.878 mm, 0.8 mm, 0.839 mm.

[0056] In some embodiments, the sheet resistance of the N-type doped layer is 14 ohms / square to 20 ohms / square, and the pitch between adjacent N-type collector grid lines is 1.019 mm to 1.296 mm. Specifically, referring to Figure 2 , the sheet resistance of the N-type doped layer is 20 ohms / square, which is approximately the sheet resistance of the N-type doped layer corresponding to the inflection point of the efficiency in the part where the efficiency is greater than or equal to 26%. More specifically, when the sheet resistance of the N-type doped layer is 14 ohms / square to 20 ohms / square and the pitch between adjacent N-type collector grid lines is 1.019 mm to 1.296 mm, the efficiency of the solar cell is greater than or equal to 26.0%, and the rate of increase in efficiency is the fastest. Therefore, in the present application, when the sheet resistance of the N-type doped layer is 14 ohms / square to 20 ohms / square and the pitch between adjacent N-type collector grid lines is 1.019 mm to 1.296 mm, by further combining and optimizing the sheet resistance of the N-type doped layer and the pitch between adjacent N-type collector grid lines, the efficiency of the solar cell is further improved. It should be noted that the material of the N-type collector grid line is not specifically limited. For example, the N-type collector grid line can be a silver collector grid line.

[0057] For example, the sheet resistance of the N-type doped layer can be 14 ohms / square, 14.7 ohms / square, 15 ohms / square, 15.3 ohms / square, 16 ohms / square, 16.5 ohms / square, 17 ohms / square, 17.7 ohms / square, 18 ohms / square, 18.5 ohms / square, 19 ohms / square, 19.5 ohms / square, 20 ohms / square, and the pitch between adjacent N-type collector grid lines can be 1.019 mm, 1.05 mm, 1.076 mm, 1.112 mm, 1.141 mm, 1.173 mm, 1.213 mm, 1.25 mm, 1.296 mm.

[0058] For another example, the sheet resistance of the N-type doping layer can be 14 ohms / square, 14.7 ohms / square, 15 ohms / square, 16.8 ohms / square, 17.6 ohms / square, 18.5 ohms / square, 19.3 ohms / square, 20.4 ohms / square, 22 ohms / square, 25 ohms / square, 23.1 ohms / square, 29.5 ohms / square, 27 ohms / square, 30 ohms / square, 32.5 ohms / square, 38 ohms / square, 39.1 ohms / square, 40 ohms / square.

[0059] For another example, if the thickness of the N-type doping layer is selected to be 120 nm, the formula is used to roughly estimate the sheet resistance R of the N-type doping layer sh . The calculated sheet resistance R of the N-type doping layer sh is approximately 29.5 ohms / square, within the range of 14 ohms / square to 40 ohms / square mentioned above. In the above formula, q is the elementary charge or the fundamental charge, q = 1.6021766208×10 -19 Coulomb, μ is the migration rate (the drift rate of carriers under a unit electric field strength) which is about 35.27 cm 2 / V·s, n is the doping concentration of the N-type doping layer, which is about 5×10 20 cm -3 , and t is the thickness of the N-type doping layer, that is, 120 nm.

[0060] More specifically, in combination with the relevant data in the above Figure 2 where the efficiency of the solar cell is greater than or equal to 26.0%, such as in the case of 26.0% to 26.5%, a fitting is performed to obtain the fitting curve between the spacing y between adjacent N-type collector grid lines and the sheet resistance x of the N-type doping layer in the back contact solar cell (BC) as shown in Figure 3 , that is, y = 0.004x 4 - 0.542x 3 + 24.53x 2 - 492.4x + 4687.3. The correlation coefficient R of this fitting curve 2 = 0.998. In this fitting curve or fitting formula, the unit of y is micrometer (μm), and the unit of x is ohms / square. Figure 3 In the above, each point includes the data on the left and the data on the right. The data on the left in each point are the sheet resistance of the N-type doping layer, and the data on the right are the spacing between adjacent N-type collector grid lines corresponding to this sheet resistance. The combination of the spacing between adjacent N-type collector grid lines and the sheet resistance of the N-type doping layer obtained from this fitting curve enables factors such as parasitic absorption, recombination current in the metal region, and lateral resistance to reach a better balance, resulting in better performance of the solar cell and higher photoelectric conversion efficiency.

[0061] In some embodiments, the sheet resistance of the P-type doped layer is from 20 ohms per square to 166 ohms per square. The sheet resistance of the P-type doped layer means that for a part of the P-type doped layer with a length of l, a width of w, and a height of d (i.e., the thickness of the P-type doped layer), at this time L = l, S = w × d, so Rsh = ρ × l / (w × d) = (ρ / d) × (l / w). Let l = w, then Rsh = (ρ / d), where ρ is the resistivity of the P-type doped layer, and the Rsh at this time is the sheet resistance of the P-type doped layer. The sheet resistance of the P-type doped layer within this range is beneficial to improving the efficiency of the solar cell, such as making the efficiency of the solar cell greater than or equal to 25.99%.

[0062] For more specific reference Figure 5 , Figure 5 is a graph showing the influence of the sheet resistance of the P-type doped layer, such as a boron-doped polysilicon layer, on the efficiency of the solar cell with respect to the spacing between adjacent P-type collector grid lines. Figure 5 The abscissa of Figure 5 is the sheet resistance of the P-type doped layer, such as a P-type doped polysilicon layer or a boron-doped polysilicon layer, Figure 5 and the ordinate of Figure 5 is the efficiency of the solar cell. In Figure 5 , the order of the curves from bottom to top corresponds to the spacings between adjacent P-type collector grid lines of 1.964 mm, 1.78 mm, 1.628 mm, 1.5 mm, 1.391 mm, 1.296 mm, 1.213 mm, 1.141 mm, 1.076 mm, 1.019 mm, 0.99 mm, 0.977 mm, 0.967 mm, 0.92 mm, 0.878 mm, 0.839 mm, a total of 15 spacings. Figure 5 In Figure 5 , the data of both points include the data on the left and the data on the right. The data on the left are all the sheet resistances of the P-type doped layer, and the data on the right are all the efficiencies of the solar cells corresponding to the sheet resistances. In the present application, through the matching and limitation of factors such as the sheet resistance of the N-type doped layer and the sheet resistance of the P-type doped layer, the solar cell can appropriately select a relatively large grid line spacing, thereby reducing the single consumption of the grid lines.

[0063] For example, the sheet resistance of the P-type doped layer can be 20 ohms / square, 20.5 ohms / square, 36 ohms / square, 40 ohms / square, 50 ohms / square, 60 ohms / square, 70 ohms / square, 80 ohms / square, 90 ohms / square, 93 ohms / square, 100 ohms / square, 120 ohms / square, 130 ohms / square, 140 ohms / square, 150 ohms / square, 160 ohms / square, 165 ohms / square, 166 ohms / square.

[0064] In some embodiments, the solar cell further includes: a first tunneling oxide layer located between the N-type doped layer and the silicon substrate. The first tunneling oxide layer and the aforementioned N-type doped layer can form a passivated contact structure, further improving the efficiency of the solar cell.

[0065] In some embodiments, the solar cell may further include: a second tunneling oxide layer located between the P-type doped layer and the silicon substrate. The second tunneling oxide layer and the first tunneling oxide layer can be formed in the same process, or the second tunneling oxide layer and the first tunneling oxide layer can be formed in different processes, and no specific limitation is made thereto. In the case where the second tunneling oxide layer and the first tunneling oxide layer are formed in different processes, there is no specific limitation on whether to form the first tunneling oxide layer first or the second tunneling oxide layer first. For example, the first tunneling oxide layer can be formed first, and then the second tunneling oxide layer can be formed subsequently.

[0066] Next, the solar cell of the second aspect is introduced. For the relevant parts in the solar cell of the second aspect, all refer to the relevant records in the solar cell of the aforementioned first aspect. To avoid repetition, only the differences from the solar cell of the first aspect are introduced.

[0067] The solar cell of the second aspect includes: a silicon substrate, an N-type doped layer, and an N-type collector grid line. The silicon substrate includes an opposite light-facing surface and a backlight-facing surface; the N-type doped layer is located on the backlight-facing surface of the silicon substrate; the thickness of the N-type doped layer is 100 nm to 140 nm, which is more favorable for several factors such as the sheet resistance of the N-type doped layer, parasitic absorption, recombination current in the passivation region, and recombination current in the metal region, making the performance of the solar cell better and the photoelectric conversion efficiency higher; the doping concentration of the N-type doped layer is 3E20 cm -3 to 7E20 cm -3, so that the sheet resistance of the N-type doped layer can be within a suitable range, enabling factors such as parasitic absorption, recombination current in the metal region, and lateral resistance to achieve a better balance, resulting in better performance and higher photoelectric conversion efficiency of the solar cell; several N-type collector grid lines spaced apart and parallel to each other, located on the side of the N-type doped layer facing away from the silicon substrate; the spacing between adjacent N-type collector grid lines is less than 1.391 mm, enabling factors such as parasitic absorption, recombination current in the metal region, and lateral resistance to achieve a better balance, resulting in better performance and higher photoelectric conversion efficiency of the solar cell.

[0068] In some embodiments, the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm. Through further optimization of the spacing between adjacent N-type collector grid lines, the efficiency of the solar cell is further improved.

[0069] In some embodiments, the N-type doped layer is located in a partial region of the backlight surface of the silicon substrate.

[0070] In some embodiments, the solar cell may further include: a P-type doped layer, located on the light-facing surface of the silicon substrate. The P-type doped layer may be located on the entire light-facing surface of the silicon substrate. The sheet resistance of the P-type doped layer is from 20 ohms per square to 166 ohms per square. The sheet resistance of the P-type doped layer within this range is beneficial to improving the efficiency of the solar cell, such as making the efficiency of the solar cell greater than or equal to 25.99%.

[0071] In some embodiments, the solar cell may further include: several P-type collector grid lines spaced apart and parallel to each other, located on the side of the P-type doped layer facing away from the silicon substrate; the spacing between adjacent P-type collector grid lines is less than or equal to the spacing between adjacent N-type collector grid lines. Specifically, because it is not easy to obtain a high doping concentration in the P-type doped layer, the spacing between adjacent P-type collector grid lines can be smaller, which can further improve the efficiency of the solar cell.

[0072] In some embodiments, from Figure 5 it can be concluded that when the spacing between adjacent P-type collector grid lines is less than 1.391 mm, the various performances of the solar cell are relatively excellent, and the efficiency of the solar cell is high, reaching 26% and above. For example, the spacing between adjacent P-type collector grid lines can be: 1.296 mm, 1.213 mm, 1.141 mm, 1.076 mm, 1.019 mm, 0.99 mm, 0.977 mm, 0.967 mm, 0.92 mm, 0.878 mm, 0.839 mm.

[0073] The other film layers in the solar cell of the second aspect are not limited, and for example, the description of the other film layers in the solar cell of the first aspect can be referred to. The specific parameter ranges of the remaining layers or structures in the solar cell of the second aspect are not limited, and for example, the relevant records in the solar cell of the first aspect can be further referred to.

[0074] The third aspect of the solar cell is described below. The relevant parts of the solar cell of the third aspect refer to the relevant description of the solar cell of the first aspect. To avoid repetition, only the differences from the solar cell of the first aspect are described.

[0075] The solar cell of the third aspect includes: a silicon substrate, an N-type doped layer, a P-type doped layer and an N-type collector grid line. The silicon substrate includes a light-facing surface and a backlight surface relative to each other; the backlight surface includes: a first conductive region and a second conductive region that are spaced apart, the space between the first conductive region and the second conductive region is used to avoid leakage, and the relative size of the first conductive region and the second conductive region is not limited. The N-type doped layer is located on the first conductive region; the P-type doped layer is located on the second conductive region, then the solar cell is a back-contact solar cell, in which the light-facing surface of the silicon substrate is not blocked by an electrode and has higher efficiency. The square resistance of the P-type doped layer is 20 ohms / square to 166 ohms / square, which is beneficial to improving the efficiency of the solar cell; the square resistance of the N-type doped layer is greater than 14 ohms / square and less than or equal to 40 ohms / square; a plurality of N-type collector grid lines are spaced and distributed in parallel and are located on the side of the N-type doped layer away from the silicon substrate; the spacing between adjacent N-type collector grid lines is less than 1.391 mm, and the square resistance of the N-type doped layer and the spacing between adjacent N-type collector grid lines are respectively within the above ranges, so that factors such as parasitic absorption, composite current of the metal area and lateral resistance can achieve a better balance, so that the performance of the solar cell is better and the photoelectric conversion efficiency is higher.

[0076] For example, the square resistance of the N-type doped layer can be 14 ohms / square, 14.7 ohms / square, 15 ohms / square, 16.8 ohms / square, 17.6 ohms / square, 18.5 ohms / square, 19.3 ohms / square, 20.4 ohms / square, 22 ohms / square, 25 ohms / square, 23.1 ohms / square, 29.5 ohms / square, 27 ohms / square, 30 ohms / square, 32.5 ohms / square, 38 ohms / square, 39.1 ohms / square, 40 ohms / square, the spacing between adjacent N-type collector grid lines can be 1.296mm, 1.213mm, 1.141mm, 1.076mm, 1.019mm, 1mm, 0.977mm, 0.967mm, 0.92mm, 0.878mm, 0.839mm, 0.8mm.

[0077] More specifically,Figure 2 The influence curve graph of the sheet resistance of the N-type doping layer and the distance between adjacent N-type collector grid lines on the efficiency of the solar cell. For example, referring to the following Figure 2 , Figure 2 In which, the abscissa is the sheet resistance of the N-type doping layer such as the N-type doped polysilicon layer or the phosphorus-doped polysilicon layer, Figure 2 The ordinate in Figure 2 is the efficiency of the solar cell. The order of each curve from bottom to top in corresponds to the distances between adjacent N-type collector grid lines as follows: 1.964 mm, 1.78 mm, 1.628 mm, 1.5 mm, 1.391 mm, 1.296 mm, 1.213 mm, 1.141 mm, 1.076 mm, 1.019 mm, 0.977 mm, 0.967 mm, 0.92 mm, 0.878 mm, 0.839 mm, a total of 15 distances. Figure 2 In , solar cells with an efficiency greater than or equal to 26%, such as 26.0% to 26.5%, are selected as solar cells with relatively high efficiency, that is, Figure 2 the part enclosed by the dashed square in . The efficiencies of the solar cells corresponding to the part below the dashed square are all less than 26%. It can be obtained from Figure 2 that among the above 15 distances between adjacent N-type collector grid lines, the distances between adjacent N-type collector grid lines greater than or equal to 1.391 mm, namely 1.964 mm, 1.78 mm, 1.628 mm, 1.5 mm, 1.391 mm, these 5 distances, and / or, the efficiencies of the solar cells corresponding to the sheet resistance of the N-type doping layer less than 14 ohms per square or greater than 40 ohms per square are all less than 26%. This shows that when the distance between adjacent N-type collector grid lines is greater than or equal to 1.391 mm, and / or, the sheet resistance of the N-type doping layer is less than 14 ohms per square or greater than 40 ohms per square, the solar cell cannot obtain a better efficiency. Therefore, in this application, the distance between adjacent N-type collector grid lines less than 1.391 mm is selected, and the sheet resistance of the N-type doping layer is 14 ohms per square to 40 ohms per square, which is beneficial to improving the efficiency of the solar cell. For example, Figure 2 in , in this application, the distance between adjacent N-type collector grid lines less than 1.391 mm is selected, and the sheet resistance of the N-type doping layer is 14 ohms per square to 40 ohms per square, then the efficiency of the solar cell is greater than or equal to 26%, and even reaches 26.5% and above.

[0078] Referring to Figure 2, the sheet resistance of the N-type doping layer is 20 ohms per square, which is approximately the sheet resistance of the N-type doping layer corresponding to the inflection point of the efficiency in the part where the efficiency is greater than or equal to 26%. More specifically, when the sheet resistance of the N-type doping layer is from 14 ohms per square to 20 ohms per square, and the spacing between adjacent N-type collector grid lines is from 1.019 mm to 1.296 mm, the efficiency of the solar cell is greater than or equal to 26.0%, and the rate of increase in efficiency is the fastest. In some embodiments, when the sheet resistance of the N-type doping layer is greater than 20 ohms per square and less than or equal to 40 ohms per square, and the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm, the efficiency of the solar cell is greater than or equal to 26.0%, and the rate of decrease in efficiency is the slowest. Therefore, in this application, the sheet resistance of the N-type doping layer is from 14 ohms per square to 20 ohms per square, and the spacing between adjacent N-type collector grid lines is from 1.019 mm to 1.296 mm; or, the sheet resistance of the N-type doping layer is greater than 20 ohms per square and less than or equal to 40 ohms per square, and the spacing between adjacent N-type collector grid lines is from 0.839 mm to 0.977 mm. Through further combined optimization of the sheet resistance of the N-type doping layer and the spacing between adjacent N-type collector grid lines, the efficiency of the solar cell is further improved.

[0079] For example, the sheet resistance of the N-type doping layer can be 14 ohms per square, 14.7 ohms per square, 15 ohms per square, 15.3 ohms per square, 16 ohms per square, 16.5 ohms per square, 17 ohms per square, 17.7 ohms per square, 18 ohms per square, 18.5 ohms per square, 19 ohms per square, 19.5 ohms per square, 20 ohms per square, and the spacing between adjacent N-type collector grid lines can be 1.019 mm, 1.05 mm, 1.076 mm, 1.112 mm, 1.141 mm, 1.173 mm, 1.213 mm, 1.25 mm, 1.296 mm. Or, the sheet resistance of the N-type doping layer can be 20.3 ohms per square, 20.7 ohms per square, 21 ohms per square, 21.3 ohms per square, 22 ohms per square, 22.5 ohms per square, 23 ohms per square, 23.5 ohms per square, 24 ohms per square, 24.5 ohms per square, 25 ohms per square, 25.6 ohms per square, 27 ohms per square, 28 ohms per square, 29.6 ohms per square, 30 ohms per square, 31.6 ohms per square, 36.2 ohms per square, 38.56 ohms per square, 40 ohms per square, and the spacing between adjacent N-type collector grid lines can be 0.977 mm, 0.971 mm, 0.967 mm, 0.9 mm, 0.92 mm, 0.913 mm, 0.878 mm, 0.8 mm, 0.839 mm.

[0080] In some embodiments, the doping concentration of the N-type doping layer is 3E20 cm -3 to 7E20 cm -3 . Specifically, the doping concentration of the N-type doping layer is an important factor affecting the sheet resistance of the N-type doping layer. In this application, the doping concentration of the N-type doping layer is limited within a relatively appropriate range, so that the sheet resistance of the N-type doping layer can be within the aforementioned required range.

[0081] For example, the doping concentration of the N-type doping layer can be 3E20 cm -3 , 3.2E20 cm -3 , 3.5E20 cm -3 , 4E20cm -3 , 4.3E20 cm -3 , 4.7E20 cm -3 , 4.21E20 cm -3 , 5E20 cm -3 , 5.2E20 cm -3 , 5.5E20 cm -3 , 6E20cm -3 , 6.3E20 cm -3 , 7E20 cm -3 .

[0082] The solar cell further includes: a plurality of P-type collector grid lines that are spaced apart and distributed in parallel, located on the side of the P-type doping layer facing away from the silicon substrate; the distance between adjacent P-type collector grid lines is less than or equal to the distance between adjacent N-type collector grid lines, which can further improve the efficiency of the solar cell. For example, the distance between adjacent P-type collector grid lines is equal to the distance between adjacent N-type collector grid lines; or, the distance between adjacent P-type collector grid lines is less than the distance between adjacent N-type collector grid lines.

[0083] In some embodiments, it can be obtained from Figure 5 that when the distance between adjacent P-type collector grid lines is less than 1.391 mm, the various performances of the solar cell are relatively excellent, and the efficiency of the solar cell is relatively high, reaching 26% and above. For example, the distance between adjacent P-type collector grid lines can be: 1.296 mm, 1.213 mm, 1.141 mm, 1.076 mm, 1.019 mm, 0.99 mm, 0.977 mm, 0.967 mm, 0.92 mm, 0.878 mm, 0.839 mm.

[0084] In some embodiments, the solar cell further includes: a first tunneling oxide layer located between the N-type doped layer and the silicon substrate; a second tunneling oxide layer located between the P-type doped layer and the silicon substrate. The second tunneling oxide layer and the first tunneling oxide layer may be formed in the same process, or the second tunneling oxide layer and the first tunneling oxide layer may be formed in different processes, and no specific limitation is made thereto. In the case where the second tunneling oxide layer and the first tunneling oxide layer are formed in different processes, there is no specific limitation on whether to form the first tunneling oxide layer first or the second tunneling oxide layer first. For example, the first tunneling oxide layer may be formed first, and then the second tunneling oxide layer may be formed subsequently.

[0085] Optionally, the spacing between the first conductive region and the second conductive region is used to avoid leakage, and the relative sizes of the first conductive region and the second conductive region are not limited.

[0086] There is no limitation on other film layers in the solar cell of the third aspect. For example, the description of other film layers in the solar cell of the foregoing first aspect may be referred to. The specific parameter ranges of the remaining layers or structures in the solar cell of the second aspect are not limited. For example, the relevant records in the solar cell of the first aspect may also be further referred to.

[0087] The solar cell of the third aspect is further explained below in conjunction with specific embodiments, and these embodiments can also be used to explain the solar cells of the first aspect and the second aspect of the present application.

[0088] The solar cell is a back-contact solar cell. The silicon substrate is an N-type doped single-crystalline silicon. The backlight surface of the silicon substrate is the backlight surface, and the backlight surface includes a first conductive region and a second conductive region that are spaced apart. The spacing between the first conductive region and the second conductive region is used to avoid leakage. The N-type doped layer is an N-type doped polycrystalline silicon layer, and the P-type doped layer is a P-type doped polycrystalline silicon layer. The N-type doped polycrystalline silicon layer is located on the first conductive region, and the P-type doped polycrystalline silicon layer is located on the second conductive region. The doping element in the N-type doped polycrystalline silicon layer includes phosphorus, and the doping element in the P-type doped layer includes boron. A second tunneling oxide layer is further provided between the P-type doped polycrystalline silicon layer and the silicon substrate, and a first tunneling oxide layer is further provided between the N-type doped polycrystalline silicon layer and the silicon substrate. The sheet resistance of the N-type doped polycrystalline silicon layer is 24 ohms per square, and the sheet resistance of the P-type doped polycrystalline silicon layer is 59 ohms per square. The spacing between adjacent N-type collector grid lines is 0.9 mm, and the spacing between adjacent P-type collector grid lines is also 0.9 mm. The various cell performance parameters of this back-contact solar cell are measured, and the measurement results and the above parameters of this back-contact are shown in the following table.

[0089] Table of various parameters of the back-contact solar cell

[0090]

[0091] In the above table, Eta is the efficiency of the back-contact solar cell, Voc is the open-circuit voltage of the back-contact solar cell, Jsc is the short-circuit current density of the back-contact solar cell, and FF is the fill factor of the back-contact solar cell. The efficiency of the back-contact solar cell has reached as high as 26.5%. The main reason is that in the back-contact solar cell, through the mutual cooperation of parameters such as the sheet resistance of the N-type doped polysilicon layer, the sheet resistance of the P-type doped polysilicon layer, the distance between adjacent N-type collector grid lines, and the distance between adjacent P-type collector grid lines, parasitic absorption, recombination current in the metal region, and lateral resistance and other factors in the back-contact solar cell reach an optimal balance, resulting in better performance and higher photoelectric conversion efficiency of the solar cell.

[0092] It should be noted that the solar cells in the foregoing first aspect, second aspect, and third aspect are all at least to enable factors such as parasitic absorption, recombination current in the metal region, and lateral resistance in the solar cell to reach an optimal balance, resulting in better performance and higher photoelectric conversion efficiency of the solar cell. Therefore, they belong to the same inventive concept.

[0093] The present invention also provides a photovoltaic module, which includes several of any of the foregoing solar cells. The photovoltaic module may further include other structures. For example, the photovoltaic module may further include encapsulation adhesive films on opposite sides of the solar cell, etc. The other structures of the photovoltaic module are not specifically limited. The photovoltaic module has the same or similar beneficial effects as any of the foregoing solar cells, and will not be elaborated here to avoid repetition.

[0094] It should be noted that in this article, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including that element.

[0095] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these fall within the protection scope of the present invention.

Claims

1. A solar cell, characterized in that, Comprising: A silicon substrate; the silicon substrate includes an opposite light-facing surface and a backlight surface; An N-type doping layer located on the backlight surface of the silicon substrate; the thickness of the N-type doping layer is 100 nm to 140 nm; A plurality of N-type collector grid lines spaced and parallelly distributed, located on the side of the N-type doping layer away from the silicon substrate, and the spacing between adjacent N-type collector grid lines is less than 1.391 mm; A P-type doping layer located on the light-facing surface of the silicon substrate; A plurality of P-type collector grid lines spaced and parallelly distributed, located on the side of the P-type doping layer away from the silicon substrate, and the spacing between adjacent P-type collector grid lines is less than or equal to the spacing between adjacent N-type collector grid lines.

2. The solar cell according to claim 1, wherein The spacing between adjacent N-type collector grid lines is 0.839 mm to 0.977 mm.

3. The solar cell according to claim 1, characterized in that, The N-type doping layer is located in a partial area of the backlight surface of the silicon substrate.

4. The solar cell according to claim 1, characterized in that, The doping concentration of the N-type doping layer is 3E20 cm -3 to 7E20 cm -3 .

5. The solar cell according to any one of claims 1 to 4, wherein The sheet resistance of the N-type doping layer is greater than 20 ohms per square, less than or equal to 40 ohms per square; and / or, The sheet resistance of the P-type doping layer is 20 ohms per square to 166 ohms per square; and / or, the spacing between adjacent P-type collector grid lines is less than 1.391 mm.

6. A solar cell, characterized in that, Comprising: A silicon substrate; the silicon substrate includes an opposite light-facing surface and a backlight surface; The N-type doped layer is located on the backlight surface of the silicon substrate; the thickness of the N-type doped layer is 100 nm to 140 nm; the doping concentration of the N-type doped layer is 3E20 cm -3 to 7E20 cm -3 ; A plurality of N-type collector grid lines spaced and parallelly distributed, located on the side of the N-type doping layer away from the silicon substrate, and the spacing between adjacent N-type collector grid lines is less than 1.391 mm.

7. The solar cell according to claim 6, wherein The spacing between adjacent N-type collector grid lines is 0.839 mm to 0.977 mm.

8. The solar cell according to claim 6, characterized in that, The N-type doping layer is located in a partial area of the backlight surface of the silicon substrate.

9. The solar cell according to claim 6, characterized in that, Further comprising: A P-type doping layer located on the light-facing surface of the silicon substrate; the sheet resistance of the P-type doping layer is 20 ohms per square to 166 ohms per square.

10. The solar cell according to any one of claims 6 to 9, characterized in that, Further comprising: A plurality of P-type collector grid lines spaced and parallelly distributed, located on the side of the P-type doping layer away from the silicon substrate, and the spacing between adjacent P-type collector grid lines is less than or equal to the spacing between adjacent N-type collector grid lines; and / or, the spacing between adjacent P-type collector grid lines is less than 1.391 mm.

11. A solar cell, characterized in that, Comprising: A silicon substrate; The silicon substrate includes an opposite light-facing surface and a backlight surface; The backlight surface includes: a first conductive region and a second conductive region spaced apart; An N-type doping layer located on the first conductive region; the sheet resistance of the N-type doping layer is greater than 14 ohms per square, less than or equal to 40 ohms per square; A P-type doping layer located on the second conductive region; the sheet resistance of the P-type doping layer is 20 ohms per square to 166 ohms per square; A plurality of N-type collector grid lines spaced and parallelly distributed, located on the side of the N-type doping layer away from the silicon substrate, and the spacing between adjacent N-type collector grid lines is less than 1.391 mm.

12. The solar cell according to claim 11, wherein The sheet resistance of the N-type doped layer is greater than 20 ohms / square and less than or equal to 40 ohms / square; The spacing between adjacent N-type collector grid lines is 0.839 mm to 0.977 mm.

13. The solar cell according to claim 11, characterized in that, The doping concentration of the N-type doping layer is 3E20 cm -3 to 7E20 cm -3 .

14. The solar cell according to claim 11, characterized in that, Also includes: A plurality of spaced and parallel P-type collector gate lines are located on the side of the P-type doped layer away from the silicon substrate, and the spacing between adjacent P-type collector gate lines is less than or equal to the spacing between adjacent N-type collector gate lines; and / or the spacing between adjacent P-type collector gate lines is less than 1.391 mm.

15. The solar cell according to any one of claims 11 to 14, characterized in that, Also includes: A first tunneling oxide layer, located between the N-type doped layer and the silicon substrate; The second tunneling oxide layer is located between the P-type doping layer and the silicon substrate.

16. A photovoltaic module, characterized in that, include: A solar cell as claimed in any one of claims 1 to 15.

Images