Solar cell and photovoltaic module

Abstract

The present application relates to the technical field of photovoltaics. Disclosed are a solar cell and a photovoltaic module. By rationally setting a ratio relationship between a transmission resistance heating power (P1) corresponding to all conductive semiconductor portions included in the solar cell and a reverse electric-leakage power (P2) corresponding to the solar cell, a reverse breakdown voltage and a hot spot risk of the solar cell are effectively reduced. Each conductive semiconductor portion in the solar cell is at least partially located between a first doped semiconductor portion and a second doped semiconductor portion, and only part of the first doped semiconductor portion is electrically connected to part of the second doped semiconductor portion by means of at least one conductive semiconductor portion. The conductivity type of different regions of each conductive semiconductor portion in the lengthwise direction thereof is opposite to the conductivity type of one of the first doped semiconductor portion and the second doped semiconductor portion. The ratio A of P1 to P2 is greater than or equal to 2%, but less than or equal to 50%.

Description

Solar cell and photovoltaic module

[0001] Cross-reference to related applications

[0002] The present application claims priority to Chinese Patent Application No. 202410794820.6, filed on June 19, 2024, entitled “Solar cell and photovoltaic module”, and the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. BACKGROUND

[0004] A solar cell is a device capable of converting the light energy of the sun into electrical energy. Specifically, when the solar cell is in a working state, sunlight shines on the semiconductor p-n junction of the solar cell, forming new hole-electron pairs. Under the action of the built-in electric field in the p-n junction, the photo-generated holes flow to the p region, and the photo-generated electrons flow to the n region. After connecting the circuit, an electric current can be generated.

[0005] From the perspective of the solar cell, the two doped semiconductor parts with opposite conduction types included in the solar cell need to be spaced apart to suppress forward leakage, so that the solar cell has a higher photoelectric conversion efficiency in the forward voltage region. From the perspective of the photovoltaic module, when the solar cells included in the photovoltaic module have two doped semiconductor parts with opposite conduction types spaced apart, the resistance between them is large, and the corresponding reverse breakdown voltage is large, resulting in a higher risk of hot spot for the solar cell. In the above case, in the existing solar cell, by locally electrically connecting the two doped semiconductor parts with opposite conduction types, the risk of hot spot of the solar cell is reduced to a certain extent.

[0006] However, the existing solar cell has a poor degree of reduction in the risk of hot spot. SUMMARY

[0007] The present application aims to provide a solar cell and a photovoltaic module, so that only part of the first doped semiconductor part and only part of the second doped semiconductor part with opposite conduction types are electrically connected through the conductive semiconductor part, and the ratio between the transmission resistance heating power corresponding to all conductive semiconductor parts included in the solar cell and the reverse leakage power corresponding to the solar cell is reasonably set. On the one hand, the leakage loss of the solar cell is effectively controlled, and on the other hand, the reverse breakdown voltage and the risk of hot spot of the solar cell are effectively reduced, so that the solar cell has a higher anti-burning ability under reverse leakage.

[0008] To achieve the above object, in a first aspect, the present application provides a solar cell, comprising: a semiconductor substrate, a first doped semiconductor part, a second doped semiconductor part, and at least one conductive semiconductor part. The first doped semiconductor part is disposed in or on the semiconductor substrate. The second doped semiconductor part is disposed in or on the semiconductor substrate. The conductive type of the second doped semiconductor part is opposite to that of the first doped semiconductor part. Each conductive semiconductor part is at least partially located between the first doped semiconductor part and the second doped semiconductor part, and only a partial region of the first doped semiconductor part and only a partial region of the second doped semiconductor part are electrically connected by the at least one conductive semiconductor part. Wherein, the corresponding transmission resistance heat power of all the conductive semiconductor parts included in the solar cell is P1, the corresponding reverse leakage power of the solar cell is P2, and the ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 50%.

[0009] In the case of the above technical solution, the conductive type of the first doped semiconductor part and the second doped semiconductor part in the solar cell provided by the present application is opposite. Moreover, each conductive semiconductor part included in the solar cell is at least partially located between the first doped semiconductor part and the second doped semiconductor part, and only a partial region of the first doped semiconductor part and only a partial region of the second doped semiconductor part are electrically connected by the at least one conductive semiconductor part. Based on this, the region between the first doped semiconductor part and the second doped semiconductor part, in which the at least one conductive semiconductor part is not disposed, can be separated by a physical interval such as an insulating groove, or a non-conductive structure such as a chemical film layer made of an insulating material or an intrinsic semiconductor material, thereby preventing the working efficiency of the solar cell from being low due to the large leakage current of the solar cell in the normal working condition caused by the fact that all the regions between the first doped semiconductor part and the second doped semiconductor part are provided with conductive semiconductor parts.

[0010] Secondly, it can be understood that the resistance corresponding to the region where the conductive semiconductor part is not arranged between the first doped semiconductor part and the second doped semiconductor part is relatively large. The conductive semiconductor part has relatively good conductivity, and can electrically connect the first doped semiconductor part and the second doped semiconductor part by manufacturing a local leakage point to form a built-in diode with a relatively low reverse breakdown voltage. Therefore, the resistance corresponding to the region where the conductive semiconductor part is arranged between the first doped semiconductor part and the second doped semiconductor part is relatively small. Therefore, in the case where the solar cell is shaded, the reverse leakage current will flow from one of the first doped semiconductor part and the second doped semiconductor part to the other through the region where the conductive semiconductor part is arranged. In the above case, when the ratio A between the transmission resistance heat power P1 corresponding to all the conductive semiconductor parts included in the solar cell and the reverse leakage power P2 corresponding to the solar cell is greater than or equal to 2% and less than or equal to 50%, the heat generated by the conductive semiconductor part itself during the reverse leakage process is relatively low, which prevents the local area of the solar cell from having a small heat reduction amplitude when a reverse bias is applied due to the serious heat generated by the conductive semiconductor part itself during the reverse leakage process, effectively reduces the reverse breakdown voltage and the risk of hot spots of the solar cell, and makes the solar cell have a high anti-burning capacity under the condition of reverse leakage.

[0011] As a possible implementation, the ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 30%.

[0012] In the case of adopting the above technical solution, the ratio A between the transmission resistance heat power P1 corresponding to all the conductive semiconductor parts included in the solar cell and the reverse leakage power P2 corresponding to the solar cell is within the above range, which is beneficial to prevent the transmission capacity requirement of the reverse leakage current of the conductive semiconductor part from being too high due to the small value of the ratio A, and is beneficial to reduce the design difficulty of the solar cell. In addition, when the ratio A is less than 30%, the transmission resistance heat power of all the conductive semiconductor parts included in the solar cell is relatively small, which can further reduce the heat reduction amplitude of the local area of the solar cell when a reverse bias is applied, and further improve the anti-burning capacity of the solar cell under the condition of reverse leakage.

[0013] As a possible implementation, the part of the conductive semiconductor part between the first doped semiconductor part and the second doped semiconductor part has B regions along the length direction of the conductive semiconductor part, and the conductive type of different regions of the conductive semiconductor part along the length direction thereof is opposite to the conductive type of one of the first doped semiconductor part and the second doped semiconductor part. B is a positive integer greater than or equal to 1. In the case where the structures of different conductive semiconductor parts included in the solar cell are the same, the ratio A between P1 and P2 satisfies the formula: wherein I mR is the maximum power point current of the solar cell. sq1 To R sqB L1 to L2 are the sheet resistances of the respective regions of a single conductive semiconductor section. B V represents the effective current transport length of each region in a single conductive semiconductor section. r The reverse breakdown voltage of the solar cell is given by N, where N is the total number of conductive semiconductor parts included in the solar cell, and a1 to a... B These represent the average width of each corresponding region of a single conductive semiconductor section.

[0014] By adopting the above technical solution, a quantitative characterization of the ratio A between the transmission resistance heating power P1 corresponding to all conductive semiconductor parts of the solar cell and the reverse leakage power P2 corresponding to the solar cell is achieved. As can be seen from the formula for the ratio A, given a fixed maximum power point current and reverse breakdown voltage of the solar cell, the sheet resistance, effective current transmission length, and average width of the corresponding region of the conductive semiconductor part, as well as the total number of conductive semiconductor parts included in the solar cell, all affect the magnitude of the ratio A. By adjusting these parameters, the transmission resistance heating power P1 corresponding to all conductive semiconductor parts of the solar cell can be controlled, ensuring that the solar cell has high resistance to burnout under reverse leakage conditions while improving the applicability of the solar cell provided in this application in different application scenarios.

[0015] As one possible implementation, the aforementioned solar cell also includes connecting electrodes. Different regions of the connecting electrodes, distributed continuously along their length, have the same conductivity type and are spaced apart from adjacent structures with opposite conductivity types.

[0016] With the above technical solution, the connecting electrode has a lower transmission resistance compared to the conductive semiconductor part. Therefore, when the solar cell is shaded, the reverse leakage current flowing to the conductive semiconductor part will preferentially flow through the connecting electrode, rather than the portion of the conductive semiconductor part covered by the connecting electrode. This further reduces the value of the ratio A between P1 and P2, i.e., reduces the heat generated by the conductive semiconductor part during reverse leakage, further improving the solar cell's resistance to burn-out under reverse leakage conditions. Furthermore, the connecting electrode has the same conductivity type in different regions continuously distributed along its length, and is spaced apart from adjacent structures with opposite conductivity types. This prevents short circuits caused by heterogeneous overlap between different regions of the connecting electrode along its length, ensuring high electrical reliability of the solar cell.

[0017] As a possible implementation, in the case that the solar cell further comprises the connection electrode, the ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 45%. In this case, the upper limit of the ratio A between P1 and P2 can be further reduced, the maximum heat generated by the conductive semiconductor part itself during the reverse leakage process is reduced, and the burnout resistance of the solar cell under the reverse leakage condition is further improved.

[0018] As a possible implementation, the conductive semiconductor part has B regions along the length direction of the conductive semiconductor part, and the conductive type of different regions of the conductive semiconductor part along the length direction of the conductive semiconductor part is opposite to the conductive type of one of the first doped semiconductor part and the second doped semiconductor part; B is a positive integer greater than or equal to 1. In the case that the solar cell comprises different conductive semiconductor parts with the same structure, the ratio A between P1 and P2 satisfies the formula: m I is the maximum power point current of the solar cell, R sq1 to R sqB are the square resistances of the respective regions of the single conductive semiconductor part, L'1 to L' B are the effective current transmission lengths of the parts of the respective regions of the single conductive semiconductor part that do not correspond to the connection electrode, V r is the reverse breakdown voltage of the solar cell, N is the total number of the conductive semiconductor parts included in the solar cell, a'1 to a' B are the average widths of the parts of the respective regions of the single conductive semiconductor part that do not correspond to the connection electrode, and Re is the equivalent resistance of the transmission resistance of the connection electrode, the contact resistance corresponding to the connection electrode, and the transmission resistance of the structure contacted by the connection electrode.

[0019] In the case of adopting the above technical solution, the quantitative characterization of the ratio A between the transmission resistance heat power P1 corresponding to all the conductive semiconductor parts included in the solar cell and the reverse leakage power P2 corresponding to the solar cell is realized in the case that the solar cell comprises the connection electrode. As can be seen from the formula of the ratio A, in the case that the maximum power point current and the reverse breakdown voltage of the solar cell are determined, not only the square resistance, the effective current transmission length and the average width of the respective regions of the conductive semiconductor part, but also the total number of the conductive semiconductor parts included in the solar cell will affect the size of the ratio A, and the above resistance R e ​The size of the contrast value A is also affected, and the transmission resistance heating power P1 of all the conductive semiconductor parts included in the solar cell can be comprehensively and accurately regulated by adjusting the above parameters, thereby improving the applicability of the solar cell provided by the application in different application scenarios while ensuring that the solar cell has high anti-burning capacity in the case of reverse leakage.

[0020] As a possible implementation, the at least one conductive semiconductor part itself has a butt joint, or a butt joint is formed between one of the first doped semiconductor part and the second doped semiconductor part and the at least one conductive semiconductor part. The butt joint includes an N-type doped part and a P-type doped part in electrical contact with the N-type doped part. The product of the carrier concentration in the N-type doped part and the carrier concentration in the P-type doped part is greater than or equal to 1×10 37 cm -6 and less than or equal to 1×10 42 cm -6 ; and / or the carrier concentration in the N-type doped part is greater than or equal to 1×10 19 cm -3 and less than or equal to 1×10 21 cm -3 ; and / or the carrier concentration in the P-type doped part is greater than or equal to 1×10 18 cm -3 and less than or equal to 1×10 21 cm -3 .

[0021] In the case of the above technical solution, the carrier concentration in the N-type doped part and the P-type doped part is proportional to the conductive capacity of itself. Based on this, the product of the carrier concentration in the N-type doped part and the P-type doped part in the butt joint is within the above range, the carrier concentration in at least one of the N-type doped part and the P-type doped part is high, which is conducive to changing the I-V characteristic of the butt joint composed of the N-type doped part and the P-type doped part, and conducive to making the output voltage of the solar cell lower than the opening voltage of the butt joint. In other words, in the case that the solar cell is in normal working condition, the above butt joint has a small normal recombination current itself at a voltage lower than the opening voltage, ensuring that the solar cell has a high forward working efficiency. At the same time, the carrier concentration in at least one of the N-type doped part and the P-type doped part is high, which is conducive to making the reverse current of the butt joint greatly increase with the increase of the reverse voltage in the case of applying a reverse voltage, reducing the transmission resistance of the butt joint in the case of reverse leakage, and further reducing the breakdown risk of the solar cell. Secondly, the carrier concentration in the N-type doped part is greater than or equal to 1×10 19 cm -3 and less than or equal to 1×10 21 cm -3and the carrier concentration in the P-type doped portion is greater than or equal to 1 x 10 18 cm -3 and less than or equal to 1 x 10 21 cm -3 The beneficial effects of the above can be referred to the foregoing, and will not be repeated here.

[0022] As a possible implementation, the doping element concentration in the N-type doped portion is greater than or equal to 6 x 10 20 cm -3 and less than or equal to 3.8 x 10 22 cm -3 In this case, the doping element concentration in the N-type doped portion is relatively high, which is conducive to increasing the carrier doping concentration in the N-type doped portion. The beneficial effects of the relatively high carrier doping concentration in the N-type doped portion can be referred to the foregoing, and will not be repeated here.

[0023] As a possible implementation, the doping element concentration in the P-type doped portion is greater than or equal to 6 x 10 19 cm -3 and less than or equal to 1.3 x 10 23 cm -3 In this case, the doping element concentration in the P-type doped portion is relatively high, which is conducive to increasing the carrier doping concentration in the P-type doped portion. The beneficial effects of the relatively high carrier doping concentration in the P-type doped portion can be referred to the foregoing, and will not be repeated here.

[0024] As a possible implementation, in the case where the first doped semiconductor portion and the second doped semiconductor portion are located on the same surface of the semiconductor substrate, when the carrier concentration in the N-type doped portion is greater than or equal to 3 x 10 20 cm -3 and the carrier concentration in the P-type doped portion is greater than or equal to 2 x 10 19 cm -3 , the ratio of the sum of the contact areas of all the contact junctions along the thickness direction of the semiconductor substrate to the area of the back surface of the solar cell is greater than or equal to 1 x 10 -10 : 1 and less than or equal to 5 x 10 -4 : 1.

[0025] In the above technical solution, it can be understood that the carrier concentration in the N-type doped portion and the P-type doped portion is related to the sheet resistance of the conductive semiconductor portion. Specifically, within a certain range, when the carrier concentration in the N-type doped portion and / or the P-type doped portion is relatively high, the sheet resistance of the conductive semiconductor portion is relatively small, and therefore, the ratio of the sum of the contact areas of the contact junctions along the thickness direction of the semiconductor substrate to the area of the back surface of the solar cell is set to be greater than or equal to 1×10 -10 :1 and less than or equal to 5×10 -4 :1. After ensuring that the reverse breakdown voltage of the solar cell is reduced to an appropriate range, the area of the contact junctions can be appropriately reduced, thereby reducing the size of the forward recombination current caused by the presence of the contact junctions, further improving the working efficiency of the solar cell in the forward voltage region, and facilitating the balance between the reverse breakdown voltage and the working efficiency of the solar cell.

[0026] As a possible implementation, when the carrier concentration in the N-type doped portion is less than 3×10 20 cm -3 and / or the carrier concentration in the P-type doped portion is less than 2×10 19 cm -3 , and the first doped semiconductor portion and the second doped semiconductor portion are located on the same surface of the semiconductor substrate, the ratio of the sum of the contact areas of the contact junctions along the thickness direction of the semiconductor substrate to the area of the back surface of the solar cell is greater than 5×10 -4 :1 and less than or equal to 1×10 -2 :1.

[0027] In the above technical solution, when the carrier concentration in the N-type doped portion is less than 3×10 20 cm -3 and / or the carrier concentration in the P-type doped portion is less than 2×10 19 cm -3 , the sheet resistance of the conductive semiconductor portion is relatively large, and the ratio of the sum of the contact areas of the contact junctions along the thickness direction of the semiconductor substrate to the area of the back surface of the solar cell is set to be greater than 5×10 -4 :1 and less than or equal to 1×10 -2 :1. Under the premise of ensuring that the size of the forward recombination current caused by the presence of the contact junctions can be reduced, the area of the contact junctions is appropriately increased to ensure that the reverse breakdown voltage of the solar cell is reduced to an appropriate range, which facilitates the balance between the reverse breakdown voltage and the working efficiency of the solar cell.

[0028] As a possible implementation, the at least one conductive semiconductor portion is located only between the first doped semiconductor portion and the second doped semiconductor portion. Alternatively, at least one of the first doped semiconductor portion and the second doped semiconductor portion is a doped semiconductor layer formed on the semiconductor substrate, and the at least one conductive semiconductor portion is located between the first doped semiconductor portion and the second doped semiconductor portion and extends to between the doped semiconductor layer and the semiconductor substrate. Alternatively, the at least one conductive semiconductor portion is a conductive semiconductor layer formed on the semiconductor substrate, and the conductive semiconductor layer is located between the first doped semiconductor portion and the second doped semiconductor portion and extends above a portion of at least one of the first doped semiconductor portion and the second doped semiconductor portion away from the semiconductor substrate.

[0029] With the above technical solution, the conductive semiconductor portion has multiple optional implementation schemes, which facilitates to determine a suitable scheme according to different application scenarios and actual manufacturing precision, and improves the applicability of the solar cell provided by the present application in different application scenarios.

[0030] In a second aspect, the present application provides a photovoltaic module, which comprises the solar cell provided by the first aspect and various implementation manners thereof.

[0031] The beneficial effects of the second aspect and various implementation manners thereof in the present application can be analyzed with reference to the beneficial effects of the first aspect and various implementation manners thereof, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings, which are included to provide a further understanding of the present application, form a part of the present application and illustrate the illustrative embodiments of the present application and its description, which serve to explain the present application and do not constitute improper limitations on the present application. In the drawings:

[0033] Fig. 1 is a schematic longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0034] Fig. 2 is a schematic longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0035] Fig. 3 is a schematic longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0036] Fig. 4 is a schematic longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0037] Fig. 5 is a schematic longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0038] Fig. 6 is a schematic longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0039] FIG. 7 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0040] FIG. 8 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0041] FIG. 9 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0042] FIG. 10 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0043] FIG. 11 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0044] FIG. 12 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0045] FIG. 13 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0046] FIG. 14 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0047] FIG. 15 is a longitudinal sectional view of a structure of a solar cell according to an embodiment of the present application;

[0048] FIG. 16 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0049] FIG. 17 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0050] FIG. 18 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0051] FIG. 19 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0052] FIG. 20 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0053] FIG. 21 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0054] FIG. 22 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0055] FIG. 23 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0056] FIG. 24 is a plan view of a partial structure of a solar cell according to an embodiment of the present application;

[0057] FIG. 25 is a graph of a rectification characteristic I-V curve of a typical diode;

[0058] FIG. 26 is a graph of an I-V curve in a case where a P-type doped portion and an N-type doped portion in a junction are heavily doped and not simultaneously degenerated;

[0059] FIG. 27 is a graph of an I-V curve in a case where a P-type doped portion and an N-type doped portion in a junction are heavily doped and simultaneously degenerated.

[0060] Reference numerals: 11 is a semiconductor substrate, 12 is a first doped semiconductor portion, 13 is a second doped semiconductor portion, 14 is a conductive semiconductor portion, 15 is a first electrode, 16 is a second electrode, 17 is a connecting electrode, 18 is a first interface passivation layer, and 19 is a second interface passivation layer. DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It should be understood, however, that the description is merely exemplary of the present application, but not intended to limit the scope of the present application. Furthermore, in the following description, well-known functions or constructions are not described in detail since they would obscure the application in unnecessary detail.

[0062] In the drawings, various structural diagrams according to embodiments of the present application are shown. These diagrams are not drawn to scale in which certain details are exaggerated for the purpose of clarity and can omit certain details. The shapes of various regions, layers, and the relative sizes and positional relationships among them shown in the diagrams are merely exemplary, and in actuality, they can deviate due to manufacturing tolerances or technical limitations, and a person skilled in the art can additionally design regions / layers having different shapes, sizes, and relative positions as needed.

[0063] In the context of the present application, when a layer / element is said to be "on" another layer / element, the layer / element can be directly on the other layer / element, or an intervening layer / element can be present therebetween. In addition, if a layer / element is "on" another layer / element in one orientation, it can be "under" the other layer / element when the orientation is reversed. In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present application and not to limit the present application.

[0064] In addition, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as implying or suggesting relative importance or an indicated number of the technical features indicated. Thus, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited. The meaning of "several" is one or more, unless otherwise explicitly specified and limited.

[0065] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0066] A solar cell is a device capable of converting solar light energy into electrical energy. Specifically, when the solar cell is in working condition, sunlight shines on the semiconductor p-n junction of the solar cell, forming new hole-electron pairs. Under the action of the built-in electric field in the p-n junction, the photo-generated holes flow to the p region, and the photo-generated electrons flow to the n region. After connecting the circuit, current can be generated.

[0067] From the perspective of the solar cell, the two doped semiconductor parts with opposite conduction types included in the solar cell need to be spaced apart to suppress forward leakage, so that the solar cell has high photoelectric conversion efficiency in the forward voltage region. From the perspective of the photovoltaic module, when the solar cells in the photovoltaic module include two doped semiconductor parts with opposite conduction types spaced apart, the resistance between them is large, and the corresponding reverse breakdown voltage is large, resulting in a high risk of hot spot for the solar cell. In the above case, in the existing solar cell, by locally electrically connecting the two doped semiconductor parts with opposite conduction types, the working efficiency of the solar cell in the forward voltage region is less affected, and the hot spot risk of the solar cell is reduced to some extent.

[0068] However, the proportion relationship between the transmission resistance heating power corresponding to the conductive semiconductor part for locally electrically connecting the two doped semiconductor parts with opposite conduction types in the existing solar cell and the reverse leakage power corresponding to the solar cell is not reasonable, resulting in poor reduction of the hot spot risk of the solar cell.

[0069] To solve the above technical problems, in a first aspect, an embodiment of the present application provides a solar cell. As shown in FIG. 1 and FIG. 2, the solar cell provided by the embodiment of the present application comprises a semiconductor substrate 11, a first doped semiconductor part 12, a second doped semiconductor part 13, and at least one conductive semiconductor part 14. The first doped semiconductor part 12 is arranged in or on the semiconductor substrate 11. The second doped semiconductor part 13 is arranged in or on the semiconductor substrate 11. The conductive type of the second doped semiconductor part 13 is opposite to that of the first doped semiconductor part 12. Each conductive semiconductor part 14 is at least partially located between the first doped semiconductor part 12 and the second doped semiconductor part 13, and only a partial region of the first doped semiconductor part 12 and only a partial region of the second doped semiconductor part 13 are electrically connected by the at least one conductive semiconductor part 14. Wherein, the corresponding transmission resistance heat power of all the conductive semiconductor parts 14 of the solar cell is P1, the corresponding reverse leakage power of the solar cell is P2, and the ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 50%.

[0070] As shown in FIG. 1 and FIG. 2, the conductive type of the first doped semiconductor part 12 and the second doped semiconductor part 13 in the solar cell provided by the embodiment of the present application is opposite. Moreover, each conductive semiconductor part 14 included in the solar cell is at least partially located between the first doped semiconductor part 12 and the second doped semiconductor part 13, and only partial areas of the first doped semiconductor part 12 and the second doped semiconductor part 13 are electrically connected by the at least one conductive semiconductor part 14. The areas between the first doped semiconductor part 12 and the second doped semiconductor part 13, which are not provided with the conductive semiconductor part 14, can be separated by a physical interval such as an insulating groove, or a non-conductive structure such as a chemical film layer made of an insulating material or an intrinsic semiconductor material, to prevent the working efficiency of the solar cell from being low due to the large leakage current when the solar cell is in the normal working condition because the areas between the first doped semiconductor part 12 and the second doped semiconductor part 13 are all provided with the conductive semiconductor part 14. Secondly, it can be understood that the resistance corresponding to the areas between the first doped semiconductor part 12 and the second doped semiconductor part 13, which are not provided with the conductive semiconductor part 14, is relatively large. Because the conductive semiconductor part 14 has relatively good conductivity, the first doped semiconductor part 12 and the second doped semiconductor part 13 can be electrically connected by manufacturing local leakage points to form a built-in diode with a relatively low reverse breakdown voltage, so the resistance corresponding to the areas between the first doped semiconductor part 12 and the second doped semiconductor part 13, which are provided with the conductive semiconductor part 14, is relatively small. Therefore, in the case of shading of the solar cell, the reverse leakage current will flow from one of the first doped semiconductor part 12 and the second doped semiconductor part 13 to the other through the areas where the conductive semiconductor part 14 is located. When the ratio A between the transmission resistance heat power P1 corresponding to all the conductive semiconductor parts 14 included in the solar cell in the embodiment of the present application and the reverse leakage power P2 corresponding to the solar cell is greater than or equal to 2% and less than or equal to 50%, the heat generated by the conductive semiconductor part 14 itself during the reverse leakage process is relatively low, which prevents the local area of the solar cell from having a small decrease in heat when a reverse bias is applied due to the serious heat generated by the conductive semiconductor part 14 itself during the reverse leakage process, effectively reduces the reverse breakdown voltage and the risk of hot spots of the solar cell, and makes the solar cell have a high anti-burning capacity in the case of reverse leakage.

[0071] In actual application, the type of the solar cell provided by the embodiment of the present application is not specifically limited. Specifically, the solar cell provided by the embodiment of the present application can be a double-sided contact cell, that is, the positive electrode and the negative electrode of the solar cell are respectively arranged on opposite surfaces of the solar cell. Alternatively, the solar cell provided by the embodiment of the present application can also be a back contact cell, that is, the positive electrode and the negative electrode of the solar cell are arranged at intervals on the same surface of the solar cell.

[0072] For the semiconductor substrate, the embodiments of the present application do not make specific limitation on the structure, material and conductive type of the semiconductor substrate. The semiconductor substrate can be a semiconductor substrate on which no structure is formed, or the semiconductor substrate can also be a semiconductor substrate on which some structures are formed. When the semiconductor substrate is a semiconductor substrate on which some structures are formed, the structures formed on the semiconductor substrate can be set according to actual needs, which are not specifically limited here. For example, the semiconductor substrate can include a semiconductor substrate and a surface passivation layer formed on the semiconductor substrate.

[0073] As for the material of the semiconductor substrate, the material of the semiconductor substrate can include any one of semiconductor materials such as silicon, silicon-germanium, germanium or gallium arsenide. Secondly, the semiconductor substrate can be a P-type semiconductor substrate, an N-type semiconductor substrate or an intrinsic semiconductor substrate.

[0074] As for the first doped semiconductor part, from the aspect of the forming position, the first doped semiconductor part can be determined according to the type of the solar cell. When the solar cell is a double-sided contact cell, the first doped semiconductor part can be arranged on the side corresponding to the front surface of the solar cell of the semiconductor substrate, or can be arranged on the side corresponding to the back surface of the solar cell of the semiconductor substrate. Secondly, as shown in FIG. 2 and FIG. 3, when the solar cell is a double-sided contact cell, the first doped semiconductor part 12 can be arranged only in a partial region of the corresponding surface of the semiconductor substrate 11, or can be arranged in the whole region of the corresponding surface of the semiconductor substrate 11. As shown in FIG. 1, when the solar cell is a back contact cell, the first doped semiconductor part 12 is arranged in a partial region of the side corresponding to the back surface of the solar cell of the semiconductor substrate 11.

[0075] Specifically, the first doped semiconductor part can be a doped semiconductor region arranged in the corresponding region of the semiconductor substrate, or can be a doped semiconductor layer arranged on the corresponding region of the semiconductor substrate. When the first doped semiconductor part is a doped semiconductor layer arranged on the corresponding region of the semiconductor substrate, the material of the first doped semiconductor part can include any one of semiconductor materials such as silicon, silicon-germanium, germanium or gallium arsenide. From the aspect of the arrangement form of the material, the crystal phase of the first doped semiconductor part can be amorphous, microcrystalline, nanocrystalline, single crystal or polycrystalline, etc.

[0076] Secondly, as shown in FIG. 1 to FIG. 3, when the first doped semiconductor part 12 is a doped semiconductor layer arranged on the corresponding region of the semiconductor substrate 11, the first doped semiconductor part 12 can be directly formed on the corresponding region of the semiconductor substrate 11. Alternatively, as shown in FIG. 4, the solar cell can further include a first interface passivation layer 18 between the semiconductor substrate 11 and the first doped semiconductor part 12. The material and thickness of the first interface passivation layer 18 can be set according to the material of the first doped semiconductor part 12 and actual requirements, and are not specifically limited here. For example, when the first doped semiconductor part is a doped polysilicon layer, the first interface passivation layer 18 is a tunneling passivation layer. For another example, when the first doped semiconductor part 12 is a doped amorphous silicon layer, the first interface passivation layer 18 is an intrinsic amorphous silicon layer.

[0077] In addition, the carrier concentration and the doping element concentration in the first doped semiconductor part 12 are not specifically limited in the embodiments of the present application, and can be applied to the solar cell provided by the embodiments of the present application.

[0078] For the second doped semiconductor part 13, from the aspect of the conduction type, the conduction type of the second doped semiconductor part 13 is not specifically limited in the embodiments of the present application, and the conduction type of the second doped semiconductor part 13 can be opposite to that of the first doped semiconductor part 12. Specifically, the conduction type of the second doped semiconductor part 13 can be N type, and the conduction type of the first doped semiconductor part 12 is P type. Alternatively, the conduction type of the second doped semiconductor part 13 can also be P type, and the conduction type of the first doped semiconductor part 12 is N type.

[0079] The second doped semiconductor part 13 can be a doped semiconductor region arranged in the corresponding region of the semiconductor substrate 11, or a doped semiconductor layer arranged on the corresponding region of the semiconductor substrate 11. The specific formation position of the second doped semiconductor part 13 on the semiconductor substrate can be determined according to the type of the solar cell. In the case of a double-sided contact solar cell, the second doped semiconductor part 13 and the first doped semiconductor part 12 are arranged on the opposite two surfaces of the semiconductor substrate 11, as shown in FIGS. 2 and 3. The second doped semiconductor part 13 can be arranged on the front side of the semiconductor substrate 11 corresponding to the solar cell, and the first doped semiconductor part 12 can be arranged on the back side of the semiconductor substrate 11 corresponding to the solar cell. Alternatively, the second doped semiconductor part 13 can be arranged on the back side of the semiconductor substrate 11 corresponding to the solar cell, and the first doped semiconductor part 12 can be arranged on the front side of the semiconductor substrate 11. In addition, as shown in FIGS. 2, 3 and 5, when the solar cell is a double-sided contact solar cell, the second doped semiconductor part 13 can be arranged only in a partial region of the corresponding surface of the semiconductor substrate 11, or can be arranged in the entire region of the corresponding surface of the semiconductor substrate 11. In the case of a back contact solar cell, the second doped semiconductor part 13 and the first doped semiconductor part 12 are arranged on the back side of the semiconductor substrate 11 corresponding to the solar cell.

[0080] Specifically, when the solar cell provided by the embodiment of the present application is a double-sided contact solar cell, the region between the first doped semiconductor part 12 and the second doped semiconductor part 13 that does not correspond to the conductive semiconductor part can be separated by at least part of the side surface of the semiconductor substrate.

[0081] When the solar cell provided by the embodiment of the present application is a back contact solar cell, the surface of the semiconductor substrate 11 corresponding to the back side of the solar cell is defined as the first surface, and the surface of the semiconductor substrate 11 corresponding to the front side of the solar cell is defined as the second surface. Based on this, the distribution between the first doped semiconductor part 12 and the second doped semiconductor part 13 can be at least divided into the following two types:

[0082] The first type is shown in FIG. 1. The first doped semiconductor part 12 and the second doped semiconductor part 13 can be distributed in parallel to the first surface. At least part of each conductive semiconductor part 14 is located between only part of the first doped semiconductor part 12 and only part of the second doped semiconductor part 13 in parallel to the first surface. The region between the first doped semiconductor part 12 and the second doped semiconductor part 13 that does not correspond to the conductive semiconductor part 14 can be separated by a physical interval such as an insulating groove, or a non-conductive structure such as a chemical film layer made of insulating material or intrinsic semiconductor material.

[0083] In the second case, where the second doped semiconductor portion 13 is a doped semiconductor layer formed on the semiconductor substrate 11, the second doped semiconductor portion 13 covers the portion of the first doped semiconductor portion 12 on the side away from the semiconductor substrate 11, and at this time, at least part of each conductive semiconductor portion 14 is located between only part of the first doped semiconductor portion 12 and only part of the second doped semiconductor portion 13 in a direction parallel to the semiconductor substrate 11, and the region between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 that does not correspond to the conductive semiconductor portion 14 can be separated by a non-conductive structure such as an insulating material or a chemical film layer made of an intrinsic semiconductor material (such as a doped silicon glass layer and / or an insulating mask layer, etc.).

[0084] In terms of material, when the second doped semiconductor portion 13 is a doped semiconductor layer arranged on the corresponding region of the semiconductor substrate 11, the material of the second doped semiconductor portion 13 can include any one of a semiconductor material such as silicon, silicon-germanium, germanium, or gallium arsenide. In terms of the arrangement form of the substance, the crystal phase of the second doped semiconductor portion 13 can be amorphous, microcrystalline, nanocrystalline, single crystal, or polycrystalline, etc.

[0085] Secondly, as shown in FIG. 5, when the second doped semiconductor portion 13 is a doped semiconductor layer arranged on the corresponding region of the semiconductor substrate 11, the second doped semiconductor portion 13 can be directly formed on the corresponding region of the semiconductor substrate 11. Alternatively, as shown in FIG. 6, the solar cell can further include a second interface passivation layer 19 located between the semiconductor substrate 11 and the second doped semiconductor portion 13. The material and thickness of the second interface passivation layer 19 can be set according to the material of the second doped semiconductor portion 13 and actual needs, and are not specifically limited here. For example, when the second doped semiconductor portion 13 is a doped polysilicon layer, the second interface passivation layer 19 is a tunnel passivation layer. For another example, when the second doped semiconductor portion 13 is a doped amorphous silicon layer, the second interface passivation layer 19 is an intrinsic amorphous silicon layer.

[0086] In addition, the carrier concentration and the doping element concentration in the second doped semiconductor portion 13 are not specifically limited in the embodiments of the present application, and can be applied to the solar cell provided by the embodiments of the present application.

[0087] For the conductive semiconductor portion 14, the "between" in the above description that each conductive semiconductor portion 14 is at least partially located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 is in a broad sense. Specifically, in the case where the solar cell provided by the embodiments of the present application is a dual-sided contact solar cell, each conductive semiconductor portion 14 being at least partially located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 can mean that, as shown in FIGS. 2 and 3, the orthographic projection of each conductive semiconductor portion 14 on the side of the solar cell is at least partially between the orthographic projection of the first doped semiconductor portion 12 on the side of the solar cell and the orthographic projection of the second doped semiconductor portion 13 on the side of the solar cell. As shown in FIGS. 1 and 4, in the case where the solar cell provided by the embodiments of the present application is a back contact solar cell, each conductive semiconductor portion 14 being at least partially located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 can mean that the orthographic projection of each conductive semiconductor portion 14 on the side of the semiconductor substrate 11 corresponding to the back side of the solar cell is at least partially between the orthographic projection of the first doped semiconductor portion 12 on the side of the semiconductor substrate 11 corresponding to the back side of the solar cell and the orthographic projection of the second doped semiconductor portion 13 on the side of the semiconductor substrate 11 corresponding to the back side of the solar cell.

[0088] From the aspect of the formation position, in the solar cell provided by the embodiments of the present application, the conductive semiconductor portion 14 can be located at at least one of the following positions:

[0089] Firstly, as shown in FIG. 7, at least one conductive semiconductor portion 14 can be located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13. In this case, the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are both doped semiconductor regions formed in the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is a conductive semiconductor region formed in the semiconductor substrate 11; or the first doped semiconductor portion 12, the second doped semiconductor portion 13 and the at least one conductive semiconductor portion 14 can all be doped semiconductor layers formed on the semiconductor substrate 11. In addition, as shown in FIG. 7, the at least one conductive semiconductor portion 14 can be located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 along a direction parallel to the surface of the semiconductor substrate 11 on which the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are formed. Alternatively, as shown in FIGS. 2, 3 and 5, the at least one conductive semiconductor portion 14 can also be located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 along a direction parallel to the thickness direction of the semiconductor substrate 11.

[0090] Second, as shown in Figs. 8 to 11, at least one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 is a doped semiconductor layer formed on the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends between the doped semiconductor layer and the semiconductor substrate 11. In this case, as shown in Fig. 8, it can be that, of the first doped semiconductor portion 12 and the second doped semiconductor portion 13, only the first doped semiconductor portion 12 is a doped semiconductor layer on the semiconductor substrate 11. The at least one conductive semiconductor portion 14 is a conductive semiconductor region formed in the semiconductor substrate 11, and the second doped semiconductor portion 13 is a doped semiconductor region formed in the semiconductor substrate 11; and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends between the first doped semiconductor portion 12 and the semiconductor substrate 11. Alternatively, as shown in Fig. 9, it can be that, of the first doped semiconductor portion 12 and the second doped semiconductor portion 13, only the second doped semiconductor portion 13 is a doped semiconductor layer on the semiconductor substrate 11. The at least one conductive semiconductor portion 14 is a conductive semiconductor region formed in the semiconductor substrate 11, and the first doped semiconductor portion 12 is a doped semiconductor region formed in the semiconductor substrate 11; and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends between the second doped semiconductor portion 13 and the semiconductor substrate 11. Further alternatively, as shown in Fig. 10, it can be that the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are each a doped semiconductor layer formed on the semiconductor substrate 11, the at least one conductive semiconductor portion 14 is a conductive semiconductor region formed in the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends between the semiconductor substrate 11 and between the first doped semiconductor portion 12 and the second doped semiconductor portion 13. Still further alternatively, as shown in Fig. 11, it can be that the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are each a doped semiconductor layer formed on the semiconductor substrate 11, the at least one conductive semiconductor portion 14 is a conductive semiconductor layer formed in the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends between the semiconductor substrate 11 and between the semiconductor substrate 11 and the first doped semiconductor portion 12 and / or between the semiconductor substrate 11 and the second doped semiconductor portion 13.

[0091] Third, as shown in FIGS. 12-15, the at least one conductive semiconductor portion 14 is a conductive semiconductor layer formed on the semiconductor substrate 11, and the conductive semiconductor layer is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends over at least one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 away from the semiconductor substrate 11. In this case, as shown in FIG. 12, the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are both doped semiconductor regions formed in the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends over the first doped semiconductor portion 12 and the second doped semiconductor portion 13, respectively, away from the semiconductor substrate 11. Alternatively, as shown in FIGS. 13 and 14, one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 is a doped semiconductor region formed in the semiconductor substrate 11, and the other is a doped semiconductor layer formed on the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends over at least the doped semiconductor layer away from the semiconductor substrate 11. Alternatively, as shown in FIG. 15, the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are both doped semiconductor layers formed on the semiconductor substrate 11, and the at least one conductive semiconductor portion 14 is located between the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and extends over at least one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 away from the semiconductor substrate 11.

[0092] As can be seen from the above, the conductive semiconductor portion 14 has multiple optional schemes for setting, which facilitates determining a suitable scheme according to different application scenarios and actual manufacturing precision, and improves the applicability of the solar cell provided by the embodiments of the present application in different application scenarios.

[0093] In terms of the conductive type, the conductive type of different regions of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 is opposite to the conductive type of one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13. In the length direction of the conductive semiconductor portion 14, the conductive semiconductor portion 14 is regionally divided according to the carrier concentration and / or the doping type of the conductive semiconductor portion 14. In the length direction of the conductive semiconductor portion 14, the conductive semiconductor portion 14 can include only one region; in this case, in the length direction of the conductive semiconductor portion 14, both the carrier concentration and the doping type of the conductive semiconductor portion 14 are the same, i.e., no change. Alternatively, in the length direction of the conductive semiconductor portion 14, the conductive semiconductor portion 14 can include multiple regions; in this case, in the length direction of the conductive semiconductor portion 14, one or both of the carrier concentration and the doping type of the conductive semiconductor portion 14 changes, and two adjacent regions of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 have different carrier concentrations and / or different doping types. As shown in FIG. 16, when both the carrier concentration and the doping type of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 are the same, the conductive semiconductor portion 14 includes only one region. As shown in FIGS. 17-19, when at least one of the carrier concentration and the doping type of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 is different, the conductive semiconductor portion 14 includes multiple regions. For any region of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14, the region has a length along the length direction of the conductive semiconductor portion and a width along a direction perpendicular to the length direction of the conductive semiconductor portion. The embodiments of the present application do not specifically limit the conductive type of different regions of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14, as long as only part of the regions of the first doped semiconductor portion 12 and only part of the regions of the second doped semiconductor portion 13 can be electrically connected through the at least one conductive semiconductor portion 14.

[0094] Specifically, as shown in FIG. 16, the conductive type of different regions of the at least one conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 can be the same, in which case the conductive type of the conductive semiconductor portion 14 can be opposite to the conductive type of the first doped semiconductor portion 12 or the conductive type of the second doped semiconductor portion 13, and the one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 opposite to the conductive type of the conductive semiconductor portion 14 forms an ohmic junction with the conductive semiconductor portion 14.

[0095] Alternatively, as shown in FIGS. 17-19, the conductivity types of at least one pair of regions in different regions along the length of the at least one conductive semiconductor portion 14 can be opposite, each pair of regions being two regions adjacent along the length of the same conductive semiconductor portion 14. At this time, the pair of regions in the conductive semiconductor portion 14 whose conductivity types are opposite form a junction, and the regions in the first doped semiconductor portion 12 and the second doped semiconductor portion 13 that are in contact with the conductive semiconductor portion 14 also form a junction with the regions in the conductive semiconductor portion 14 whose conductivity types are opposite.

[0096] In actual applications, the at least one conductive semiconductor portion 14 can be integrally continuous with the first doped semiconductor portion 12 or the second doped semiconductor portion 13, i.e., the first doped semiconductor portion 12 and the at least one conductive semiconductor portion 14 can be formed simultaneously based on the same material and by the same manufacturing process (at this time, the material, the type of doping element, the carrier doping concentration, and the doping element concentration of the first doped semiconductor portion and the at least one conductive semiconductor portion are the same), or the second doped semiconductor portion 13 and the at least one conductive semiconductor portion 14 can be formed simultaneously based on the same material and by the same manufacturing process (at this time, the material, the type of doping element, the carrier doping concentration, and the doping element concentration of the second doped semiconductor portion and the at least one conductive semiconductor portion are the same).

[0097] Of course, the at least one conductive semiconductor portion 14 can also be formed separately from the first doped semiconductor portion 12 and the second doped semiconductor portion 13 on the semiconductor substrate 11, at which time the material, the type of doping element, the carrier doping concentration, and the doping element concentration of the conductive semiconductor portion 14 can be set according to actual requirements, which are not specifically limited here.

[0098] In addition, the number of conductive semiconductor portions 14 included in the solar cell according to the embodiments of the present application is not specifically limited, as long as the ratio A of the transmission resistance heating power P1 corresponding to all the conductive semiconductor portions included in the solar cell to the reverse leakage power P2 corresponding to the solar cell is greater than or equal to 2% and less than or equal to 50%. Specifically, the ratio A between P1 and P2 can be any value greater than or equal to 2% and less than or equal to 50%. For example, the ratio A between P1 and P2 can be 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, etc.

[0099] It can be understood that the smaller the value of the ratio A between P1 and P2, the lower the risk of hot spot of the solar cell, but the higher the requirement for the electrical conduction performance of the conductive semiconductor part 14, resulting in a greater difficulty in designing the solar cell. In addition, the value of the ratio A between P1 and P2 is also related to the specific structure of the solar cell. Therefore, the value of the ratio A between P1 and P2 can be determined according to the specific structure of the solar cell, as well as the actual demand and actual manufacturing process, which is not limited here.

[0100] For example, the ratio A between P1 and P2 can be greater than or equal to 2% and less than or equal to 30%. In this case, the ratio A between the transmission resistance heating power P1 corresponding to all conductive semiconductor parts 14 included in the solar cell and the reverse leakage power P2 corresponding to the solar cell is within the above range, which is beneficial to prevent the transmission capacity requirement of the reverse leakage current of the conductive semiconductor part from being too high due to the small value of the ratio A, and is beneficial to reduce the design difficulty of the solar cell. In addition, when the ratio A is less than 30%, the transmission resistance heating power of all conductive semiconductor parts 14 included in the solar cell is relatively small, which can further reduce the local area heat reduction amplitude of the solar cell when a reverse bias is applied, and further improve the anti-burning capacity of the solar cell under the condition of reverse leakage.

[0101] For example, as shown in FIGS. 20-22, the above-mentioned solar cell can further include a connecting electrode 17. The connecting electrode 17 is formed on at least one side of the conductive semiconductor part 14 away from the semiconductor substrate 11. The conductive type of different regions of the connecting electrode 17 continuously distributed along the length direction of the connecting electrode 17 is the same, and is spaced apart from the adjacent structure with opposite conductive type. In this case, compared with the conductive semiconductor part 14, the connecting electrode 17 has a lower transmission resistance. Based on this, in the case of shading of the solar cell, the reverse leakage current flowing to the conductive semiconductor part 14 will preferentially flow through the connecting electrode 17, rather than the part of the conductive semiconductor part 14 covered by the connecting electrode 17, at this time the size of the ratio A between P1 and P2 can be further reduced, that is, the heat generation of the conductive semiconductor part 14 itself during the reverse leakage process is further reduced, and the anti-burning capacity of the solar cell under the condition of reverse leakage is further improved. In addition, the conductive type of different regions of the connecting electrode 17 continuously distributed along the length direction of the connecting electrode 17 is the same, and is spaced apart from the adjacent structure with opposite conductive type, which prevents short circuit caused by different regions of the connecting electrode 17 continuously distributed along the length direction of the connecting electrode 17 from being abutted, and ensures that the solar cell has high electrical reliability.

[0102] Specifically, the part of the connecting electrode 17 formed on the two regions adjacent to each other and having the same conductive type in the same conductive semiconductor part 14 can be continuously arranged or discontinuously arranged. Secondly, the connecting electrode 17 and the adjacent structure having the opposite conductive type to itself can be spaced apart from each other as follows: as shown in FIG. 20, the connecting electrode 17 and the different region of the same conductive semiconductor part 14 having the opposite conductive type to itself are spaced apart from each other; or as shown in FIG. 21, the connecting electrode 17 and the first doped semiconductor part 12 or the second doped semiconductor part 13 having the opposite conductive type to itself can be spaced apart from each other. The length of the spacing can be determined according to the actual application scenario, as long as it can prevent the short circuit caused by the different regions of the connecting electrode 17 continuously distributed along the length direction of itself and the opposite conductive type lapping.

[0103] In addition, along the length direction of the conductive semiconductor part 14, the end of the connecting electrode 17 can extend to the first doped semiconductor part 12 or the second doped semiconductor part 13 having the same conductive type as itself; or as shown in FIG. 22, along the length direction of the conductive semiconductor part 14, the end of the connecting electrode 17 can also be electrically connected to the electrode having the same conductive type as itself. Of course, the connecting electrode can also be arranged only on part of the region along the length direction of the conductive semiconductor part 14.

[0104] For example, as shown in FIGS. 20-22, in the case where the solar cell further comprises the connecting electrode 17, the ratio A between P1 and P2 can be greater than or equal to 2% and less than or equal to 45%. For example, in this case, the ratio A between P1 and P2 can be 2%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40% or 45%, etc. In this case, the upper limit of the ratio A between P1 and P2 can be further reduced, the maximum heat generation of the conductive semiconductor part 14 itself during reverse leakage can be reduced, and the anti-burning ability of the solar cell under reverse leakage can be further improved.

[0105] Preferably, regardless of whether the solar cell includes the connecting electrode 17, in the solar cell provided by the embodiments of the present application, the ratio A between P1 and P2 can be preferably set in a range greater than or equal to 10% and less than or equal to 30% (for example, the ratio A between P1 and P2 can be 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28% or 30, etc.), so as to have a lower hot spot risk while having a higher working efficiency of the solar cell. In this case, the corresponding reverse breakdown voltage of the solar cell provided by the embodiments of the present application can be greater than or equal to 2V and less than or equal to 9V (for example, it can be 2V, 3V, 4V, 5V, 6V, 7V, 8V or 9V, etc.). In some examples, by adjusting the ratio A between P1 and P2 to 15% to 25%, the corresponding reverse breakdown voltage of the solar cell provided by the embodiments of the present application can be reduced to 5V to 8V.

[0106] In addition, the embodiments of the present application also provide a calculation method of the ratio A between P1 and P2, so as to realize the quantitative characterization of the ratio A between the transmission resistance heating power P1 of all the conductive semiconductor parts 14 included in the solar cell and the corresponding reverse leakage power P2 of the solar cell.

[0107] For example, the part of the conductive semiconductor part 14 between the first doped semiconductor part 12 and the second doped semiconductor part 13 has B regions along the length direction thereof, B being a positive integer greater than or equal to 1. And in the case that the structures of different conductive semiconductor parts 14 included in the solar cell are the same, the ratio A between P1 and P2 satisfies the formula: Wherein, I m is the maximum power point current of the solar cell, R sq1 to R sqB are the respective sheet resistances of the respective regions of the single conductive semiconductor part 14, L1 to L B are the effective current transmission lengths of the respective regions of the single conductive semiconductor part 14, V r is the reverse breakdown voltage of the solar cell, N is the total number of the conductive semiconductor parts 14 included in the solar cell, a1 to a Brespectively, are average widths of the respective regions of the single conductive semiconductor portion. For any region of a conductive semiconductor portion along a length direction of the conductive semiconductor portion, the region has a length along the length direction of the conductive semiconductor portion and a width along a direction perpendicular to the length direction of the conductive semiconductor portion. In this case, as can be seen from the formula of the ratio A above, when the maximum power point current and the reverse breakdown voltage of the solar cell are determined, the sheet resistance, the effective current transmission length, and the average width of the respective regions of the conductive semiconductor portion, and the total number of the conductive semiconductor portions 14 included in the solar cell all affect the size of the ratio A, and the transmission resistance heating power PI of all the conductive semiconductor portions 14 included in the solar cell can be regulated by adjusting the above parameters, thereby ensuring that the solar cell has a high anti-burning capacity under reverse leakage conditions while improving the applicability of the solar cell provided in the embodiments of the present application in different application scenarios.

[0108] The same structure of the different conductive semiconductor portions 14 in the embodiments of the present application means that the number of regions of the different conductive semiconductor portions 14 along the length direction of the conductive semiconductor portions is the same, and the carrier concentration, the doping type, the length, and the width of the corresponding regions are all the same.

[0109] Specifically, the maximum power point current I m of the solar cell and the reverse breakdown voltage V r of the solar cell can be obtained by electrical testing of the solar cell. sq1 to R sqB can be determined by measurement and / or calculation. B to L B can be obtained by measurement. As shown in FIGS. 16 to 19, in the case where the solar cell does not include the above-mentioned connecting electrode 17, different regions of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 are divided according to the difference in the carrier concentration and / or the doping type of the different regions. As shown in FIG. 16, when the carrier concentration and the doping type of the different regions of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 are all the same, the conductive semiconductor portion 14 includes only one region. As shown in FIGS. 17 to 19, when at least one of the carrier concentration and the doping type of the different regions of the conductive semiconductor portion 14 along the length direction of the conductive semiconductor portion 14 is different, the conductive semiconductor portion 14 includes a plurality of regions. In the above case, as shown in FIGS. 16 to 19, L B respectively, are effective current transmission lengths of the respective regions of the conductive semiconductor portion 14, i.e., the effective transmission length of the carriers of the region when transmitting the leakage current. B respectively, are average widths of the respective regions of the conductive semiconductor portion 14, i.e., the average width of the region along the direction parallel to the direction of the butt joint when transmitting the leakage current.

[0110] For example, in the case that the solar cell further comprises the connection electrode 17 and the conductive semiconductor part 14 has B regions along the length direction of itself between the first doped semiconductor part 12 and the second doped semiconductor part 13, and B is a positive integer greater than or equal to 1, when the solar cell comprises different conductive semiconductor parts with the same structure, the ratio A between P1 and P2 satisfies the formula: wherein I m is the maximum power point current of the solar cell, R sq1 to R sqB are the square resistance of the respective regions of the single conductive semiconductor part, respectively, L'1 to L' B are the effective current transmission length of the part of the respective regions of the single conductive semiconductor part 14 that does not correspond to the connection electrode 17, V r is the reverse breakdown voltage of the solar cell, N is the total number of the conductive semiconductor parts included in the solar cell, a'1 to a' B are the average width of the part of the respective regions of the single conductive semiconductor part 14 that does not correspond to the connection electrode, and Re is the equivalent resistance of the transmission resistance of the connection electrode 17, the contact resistance corresponding to the connection electrode 17, and the transmission resistance of the structure contacted by the connection electrode 17. In this case, when the maximum power point current and the reverse breakdown voltage of the solar cell are determined, not only the square resistance, the effective current transmission length and the average width of the respective regions of the conductive semiconductor part 14, and the total number of the conductive semiconductor parts 14 included in the solar cell, but also the above-mentioned resistance R e will affect the size of the ratio A. By adjusting the above-mentioned parameters, the transmission resistance heating power P1 corresponding to all the conductive semiconductor parts included in the solar cell can be comprehensively and accurately controlled, while ensuring that the solar cell has high anti-burning capacity under reverse leakage condition, the applicability of the solar cell provided by the present application in different application scenarios is improved.

[0111] Specifically, the maximum power point current I m of the above-mentioned solar cell, and the reverse breakdown voltage V r of the solar cell can be obtained by electrical testing of the solar cell. R sq1 to R sqB can be determined by measurement and / or calculation. The resistance R e can be determined by measurement and / or calculation. L'1 to L' B , and a'1 to a' Bmay be obtained by measurement. As shown in FIGS. 23 and 24, in the case where the solar cell includes the above-mentioned connecting electrode 17, different regions of the conductive semiconductor portion 14 are divided in accordance with differences in carrier concentration and / or doping type of the different regions along the length direction of the conductive semiconductor portion 14. Among them, as shown in FIG. 21, when the carrier concentration and the doping type of the different regions along the length direction of the conductive semiconductor portion 14 are both the same, the conductive semiconductor portion 14 includes only one region. As shown in FIG. 20, and FIGS. 22 to 24, when at least one of the carrier concentration and the doping type of the different regions along the length direction of the conductive semiconductor portion 14 is different, the conductive semiconductor portion 14 includes a plurality of regions. In the above-mentioned cases, as shown in FIGS. 23 and 24, L'1 to L'4 B respectively are the effective current transmission lengths of the portions of the respective regions of the conductive semiconductor portion 14 that do not correspond to the connecting electrode 17, i.e. the effective transmission lengths of the portions of the regions that do not have the connecting electrode 17 formed thereon along the length direction of the conductive semiconductor portion 14 when transmitting the leakage current. B respectively are the average widths of the portions of the respective regions of the conductive semiconductor portion 14 that do not correspond to the connecting electrode 17, i.e. the average widths of the portions of the regions that do not have the connecting electrode 17 formed thereon along the direction parallel to the butt joint when transmitting the leakage current.

[0112] As can be seen from the above, regardless of whether the solar cell includes the connecting electrode 17, the specific conductive type, carrier doping concentration, doping element concentration and size of the different regions of the conductive semiconductor portion 14 along the length direction thereof will all affect the ratio A between P1 and P2. Based on this, the requirements for the transmission resistance heat power of all the conductive semiconductor portions in the solar cell in the actual application scenario, and the requirements for reducing the hot spot risk of the solar cell can be determined, which are not specifically limited here.

[0113] For example, as shown in the foregoing, in the case where the at least one conductive semiconductor portion 14 itself has a butt joint, or a butt joint is formed between one of the first doped semiconductor portion 12 and the second doped semiconductor portion 13 and the at least one conductive semiconductor portion 14, the butt joint includes an N-type doped portion, and a P-type doped portion in electrical contact with the N-type doped portion. In the above-mentioned case, the product of the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion can be greater than or equal to 1 x 10 37 cm -6 , and less than or equal to 1 x 10 42 cm -6 . For example: the product of the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion can be 1 x 10 37 cm -6 , 5 x 10 37 cm -6 , 1 x 1038 cm -6 , 5 x 10 38 cm -6 , 1 x 10 39 cm -6 , 5 x 10 39 cm -6 , 1 x 10 40 cm -6 , 5 x 10 40 cm -6 , 1 x 10 41 cm -6 , 5 x 10 41 cm -6 , 1 x 10 42 cm -6 , etc. In this case, the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion are proportional to their own conductive ability. Based on this, as shown in FIG. 26 and FIG. 27, when the product of the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion in the butt joint is within the above range, the carrier concentration in at least one of the N-type doped portion and the P-type doped portion is high, which is conducive to changing the I-V characteristic of the butt joint formed by the N-type doped portion and the P-type doped portion, and conducive to making the output voltage of the solar cell lower than the turn-on voltage of the butt joint, thereby solving the problem of high leakage loss caused by the rapid increase of the forward current of the butt joint after turning on when the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion are low, as shown in FIG. 25. In other words, when the solar cell is in normal working condition, the above-mentioned butt joint has a small normal recombination current corresponding to itself at a voltage lower than the turn-on voltage, which ensures that the solar cell has a high forward working efficiency. At the same time, the carrier concentration in at least one of the N-type doped portion and the P-type doped portion is high, which is conducive to making the reverse current of the butt joint increase rapidly with the increase of the reverse voltage, reducing the transmission resistance of the butt joint in the reverse leakage, and further reducing the breakdown risk of the solar cell.

[0114] For example, the carrier concentration in the N-type doped portion in the above-mentioned butt joint can be greater than or equal to 1 x 10 19 cm -3 and less than or equal to 1 x 10 21 cm -3 . For example, the carrier concentration in the N-type doped portion can be 1 x 10 19 cm -3 , 3 x 10 19 cm -3 , 5 x 10 19 cm -3 , 8 x 10 19 cm -3 , 1 x 10 20cm -3 , 5 x 10 20 cm -3 , 8 x 10 20 cm -3 , 1 x 10 20 cm -3 , or 3 x 10 21 cm -3 , etc. The beneficial effects in this case can be referred to the beneficial effect analysis of the product of the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion being greater than or equal to 1 x 10 37 cm -6 and less than or equal to 1 x 10 42 cm -6 , which is not repeated here.

[0115] Exemplarily, the carrier concentration in the P-type doped portion in the butt joint described above can be greater than or equal to 1 x 10 18 cm -3 and less than or equal to 1 x 10 21 cm -3 . For example: the carrier concentration in the P-type doped portion can be 1 x 10 18 cm -3 , 5 x 10 18 cm -3 , 1 x 10 19 cm -3 , 3 x 10 19 cm -3 , 5 x 10 19 cm -3 , 8 x 10 19 cm -3 , 1 x 10 20 cm -3 , 3 x 10 20 cm -3 , 5 x 10 20 cm -3 , 8 x 10 20 cm -3 , or 1 x 10 21 cm -3 , etc. The beneficial effects in this case can be referred to the beneficial effect analysis of the product of the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion being greater than or equal to 1 x 10 37 cm -6 and less than or equal to 1 x 10 42 cm -6 , which is not repeated here.

[0116] Exemplarily, the concentration of the doped element in the N-type doped portion described above can be greater than or equal to 6 x 10 20 cm-3 And less than or equal to 3.8 × 10 22 cm -3 For example, the dopant concentration in the N-type doped region can be 6 × 10⁻⁶. 20 cm -3 8×10 20 cm -3 1×10 21 cm -3 3×10 21 cm -3 5×10 21 cm -3 8×10 21 cm -3 1×10 22 cm -3 3×10 22 cm -3 Or 3.8×10 22 cm -3 In this case, the concentration of dopant elements in the N-type doped region is relatively high, which is beneficial for increasing the carrier doping concentration in the N-type doped region. The beneficial effects of a higher carrier doping concentration in the N-type doped region can be referred to the previous text, and will not be repeated here.

[0117] For example, the concentration of doped elements in the aforementioned P-type doped region can be greater than or equal to 6 × 10⁻⁶. 19 cm -3 And less than or equal to 1.3 × 10 23 cm -3 For example, the dopant concentration in the P-type doped region can be 6 × 10⁻⁶. 19 cm -3 1×10 20 cm -3 6×10 20 cm -3 8×10 20 cm -3 1×10 21 cm -3 3×10 21 cm -3 5×10 21 cm -3 8×10 21 cm -3 1×10 22 cm -3 3×10 22 cm -3 5×10 22 cm -3 Or 1.3×10 23 cm -3etc. In this case, the doping element concentration in the P-type doped part is relatively high, which is conducive to increasing the carrier doping concentration in the P-type doped part. The beneficial effects of the high carrier doping concentration in the P-type doped part can be referred to the foregoing, and will not be described here.

[0118] As for the size of the conductive semiconductor part 14, the size of the conductive semiconductor part 14 is related to the butt joint area of the butt joint along the thickness direction of the semiconductor substrate 11 corresponding to the conductive semiconductor part 14, and the size of the butt joint area along the thickness direction of the semiconductor substrate 11 directly affects the transmission resistance heat power of the conductive semiconductor part 14. Therefore, by comprehensively adjusting the carrier concentration in the N-type doped part, the carrier concentration in the P-type doped part, and the butt joint area along the thickness direction of the semiconductor substrate in the butt joint, the transmission resistance heat power of the conductive semiconductor part can be accurately controlled to meet the requirements of anti-hot spot of the solar cell in actual application scenarios.

[0119] For example, in the case where the first doped semiconductor part 12 and the second doped semiconductor part 13 are located on the same surface of the semiconductor substrate 11, when the carrier concentration in the N-type doped part is greater than or equal to 3×10 20 cm -3 , and the carrier concentration in the P-type doped part is greater than or equal to 2×10 19 cm -3 , the ratio of the sum of the butt joint areas along the thickness direction of the semiconductor substrate 11 of all the conductive semiconductor parts 14 included in the solar cell to the area of the back surface of the solar cell can be greater than or equal to 1×10 -10 :1 and less than or equal to 5×10 -4 :1. For example: in the case where the first doped semiconductor part 12 and the second doped semiconductor part 13 are located on the same surface of the semiconductor substrate 11, when the carrier concentration in the N-type doped part is 3×10 20 cm -3 , 5×10 20 cm -3 , 8×10 20 cm -3 , or 1×10 21 cm -3 , etc., and the carrier concentration in the P-type doped part is 2×10 19 cm -3 , 3×10 19 cm -3 , 5×10 19 cm -3 , 8×10 19 cm -3 , 1×10 20 cm -3 , or 3×10 20 cm-3 The ratio of the sum of the contact areas of the contact junctions of all the conductive semiconductor portions 14 included in the solar cell along the thickness direction of the semiconductor substrate 11 to the area of the back surface of the solar cell can be 1 x 10 -10 :1, 5 x 10 -10 :1, 1 x 10 -9 :1, 5 x 10 -9 :1, 1 x 10 -8 :1, 5 x 10 -8 :1, 1 x 10 -7 :1, 5 x 10 -7 :1, 1 x 10 -6 :1, 1 x 10 -5 :1, 1 x 10 -4 :1, or 5 x 10 -4 :1. In this case, it can be understood that the carrier concentration in the N-type doped portion and the carrier concentration in the P-type doped portion are related to the sheet resistance of the conductive semiconductor portion 14. Specifically, within a certain range, when the carrier concentration in the N-type doped portion and / or the carrier concentration in the P-type doped portion is higher, the sheet resistance of the conductive semiconductor portion is relatively smaller, and thus the ratio of the sum of the contact areas of the contact junctions of all the conductive semiconductor portions 14 included in the solar cell along the thickness direction of the semiconductor substrate 11 to the area of the back surface of the solar cell is set to be greater than or equal to 1 x 10 -10 :1 and less than or equal to 5 x 10 -4 :1. After ensuring that the reverse breakdown voltage of the solar cell is reduced to an appropriate range, the area of the contact junction can be appropriately reduced, thereby reducing the size of the forward recombination current generated due to the presence of the contact junction, further improving the high work efficiency of the solar cell in the forward voltage region, and facilitating the balance between the reverse breakdown voltage and the work efficiency of the solar cell.

[0120] For example, in the case where the first doped semiconductor portion and the second doped semiconductor portion are located on the same surface of the semiconductor substrate, when the carrier concentration in the N-type doped portion is less than 3 x 10 20 cm -3 and / or the carrier concentration in the P-type doped portion is less than 2 x 10 19 cm -3 , the ratio of the sum of the contact areas of the contact junctions of all the conductive semiconductor portions 14 included in the solar cell along the thickness direction of the semiconductor substrate 11 to the area of the back surface of the solar cell can be greater than 5 x 10 -4 :1 and less than or equal to 1 x 10 -2 :1. For example: in the case where the first doped semiconductor portion 12 and the second doped semiconductor portion 13 are located on the same surface of the semiconductor substrate 11, when the carrier concentration in the N-type doped portion is 1 x 1019 cm -3 , 3 x 10 19 cm -3 , 5 x 10 19 cm -3 , 8 x 10 19 cm -3 or 3 x 10 20 cm -3 and / or the carrier concentration in the P-type doped portion is 1 x 10 18 cm -3 , 5 x 10 18 cm -3 , 1 x 10 19 cm -3 or 2 x 10 19 cm -3 , the ratio of the sum of the contact areas of the contact junctions of all the conductive semiconductor portions 14 along the thickness direction of the semiconductor substrate 11 to the area of the back surface of the solar cell can be 6 x 10 -4 : 1, 8 x 10 -4 : 1, 1 x 10 -3 : 1, 3 x 10 -3 : 1, 5 x 10 -3 : 1, 8 x 10 -3 : 1 or 1 x 10 -2 : 1, etc. In this case, when the carrier concentration in the N-type doped portion is less than 3 x 10 20 cm -3 and / or the carrier concentration in the P-type doped portion is less than 2 x 10 19 cm -3 , the sheet resistance of the conductive semiconductor portion is relatively large, the ratio of the sum of the contact areas of the contact junctions of all the conductive semiconductor portions 14 along the thickness direction of the semiconductor substrate 11 to the area of the back surface of the solar cell is set to be greater than 5 x 10 -4 : 1 and less than or equal to 1 x 10 -2 : 1, and by appropriately increasing the area of the contact junctions, the reverse breakdown voltage of the solar cell is ensured to be reduced to an appropriate range, which is conducive to balancing the reverse breakdown voltage and the working efficiency of the solar cell.

[0121] In some cases, as shown in FIGS. 20-22, the solar cell can further include a first electrode 15 and a second electrode 16. The first electrode 15 is disposed on the side of the first doped semiconductor portion 12 facing away from the semiconductor substrate 11 and is in ohmic contact with the first doped semiconductor portion 12. The second electrode 16 is disposed on the side of the second doped semiconductor portion 13 facing away from the semiconductor substrate 11 and is in ohmic contact with the second doped semiconductor portion 13. The first electrode 15 and the second electrode 16 are physically insulated. Based on this, the carriers of the corresponding conductivity type are guided out through the first electrode 15 and the second electrode 16, which is conducive to the formation of a photocurrent. The above-mentioned physical insulation refers to no contact, i.e., the first electrode 15 and the second electrode 16 do not contact each other. The embodiments of the present application do not make specific limitations on the materials of the first electrode 15 and the second electrode 16.

[0122] In a second aspect, the embodiments of the present application provide a photovoltaic module, which includes the solar cell provided in the above first aspect and various implementation manners thereof.

[0123] The beneficial effects of the second aspect and various implementation manners thereof in the embodiments of the present application can be analyzed with reference to the beneficial effects in the first aspect and various implementation manners thereof, which will not be described herein again.

[0124] In the above description, the technical details such as the patterning of each layer, etching, etc. are not described in detail. However, those skilled in the art should understand that the layers, regions, etc. of the required shape can be formed by various technical means. In addition, those skilled in the art can also design methods that are not exactly the same as the methods described above in order to form the same structure. In addition, although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination.

[0125] The embodiments of the present application are described above. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents. Unless there is a technical obstacle or contradiction, various technical features disclosed in the present application can be freely combined to form additional embodiments, which are all within the scope of protection of the present application. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present application, and these substitutions and modifications should all fall within the scope of the present application.

Claims

1. A solar cell, comprising: Semiconductor substrate, A first doped semiconductor portion is disposed within or on the semiconductor substrate; A second doped semiconductor portion is disposed within or on the semiconductor substrate; the second doped semiconductor portion and the first doped semiconductor portion have opposite conductivity types. And at least one conductive semiconductor portion, each of the conductive semiconductor portions being at least partially located between the first doped semiconductor portion and the second doped semiconductor portion, and only a portion of the first doped semiconductor portion and only a portion of the second doped semiconductor portion being electrically connected through the at least one conductive semiconductor portion; wherein... The heat generation power corresponding to the transmission resistance of all the conductive semiconductor parts included in the solar cell is P1, the reverse leakage power corresponding to the solar cell is P2, and the ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 50%.

2. The solar cell according to claim 1, wherein, The ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 30%.

3. The solar cell according to claim 1, wherein, The portion of the conductive semiconductor portion located between the first doped semiconductor portion and the second doped semiconductor portion has B regions along its own length direction. The conductivity type of the different regions of the conductive semiconductor portion along its own length direction is opposite to the conductivity type of either the first doped semiconductor portion or the second doped semiconductor portion; B is a positive integer greater than or equal to 1. When the different conductive semiconductor portions included in the solar cell have the same structure, the ratio A between P1 and P2 satisfies the formula: in, I m R is the maximum power point current of the solar cell. sq1 To R sqB L1 to L2 are the sheet resistances of the respective regions of each of the individual conductive semiconductor portions. B V represents the effective current transport length of each corresponding region of a single conductive semiconductor portion. r The reverse breakdown voltage of the solar cell is given by N, where N is the total number of conductive semiconductor portions included in the solar cell, and a1 to a... B These are the average widths of the respective regions of a single conductive semiconductor portion.

4. The solar cell according to claim 1, wherein, The solar cell further includes a connecting electrode; the connecting electrode is formed at least on the side of the conductive semiconductor portion away from the semiconductor substrate; different regions of the connecting electrode are continuously distributed along their own length direction with the same conductivity type and are spaced apart from adjacent structures with the opposite conductivity type.

5. The solar cell according to claim 4, wherein, The ratio A between P1 and P2 is greater than or equal to 2% and less than or equal to 45%.

6. The solar cell according to claim 4, wherein, The portion of the conductive semiconductor portion located between the first doped semiconductor portion and the second doped semiconductor portion has B regions along its own length direction. The conductivity type of the different regions of the conductive semiconductor portion along its own length direction is opposite to the conductivity type of either the first doped semiconductor portion or the second doped semiconductor portion; B is a positive integer greater than or equal to 1. When the different conductive semiconductor portions included in the solar cell have the same structure, the ratio A between P1 and P2 satisfies the formula: in, I m R is the maximum power point current of the solar cell. sq1 To R sqB The sheet resistances of the respective regions of each of the individual conductive semiconductor portions, L′1 to L′, are respectively. B V represents the effective current transmission length of the portion of each region of a single conductive semiconductor portion that does not correspond to the connecting electrode. r The reverse breakdown voltage of the solar cell is given by N, where N is the total number of conductive semiconductor portions included in the solar cell, and a′1 to a′ B Re represents the average width of the portion of each region of a single conductive semiconductor that does not correspond to the connecting electrode, and Re is the equivalent resistance of the transmission resistance of the connecting electrode, the contact resistance corresponding to the connecting electrode, and the transmission resistance of the structure in contact with the connecting electrode.

7. The solar cell according to claim 1, wherein, At least one of the conductive semiconductor portions has a mating junction, or one of the first doped semiconductor portion and the second doped semiconductor portion forms a mating junction with at least one of the conductive semiconductor portions; the mating junction includes an N-type doped portion and a P-type doped portion electrically in contact with the N-type doped portion; wherein... The product of the carrier concentration in the N-type doped region and the carrier concentration in the P-type doped region is greater than or equal to 1 × 10⁻⁶. 37 cm -6 And less than or equal to 1×10 42 cm -6 ; and / or, The carrier concentration within the N-type doped region is greater than or equal to 1 × 10⁻⁶. 19 cm -3 And less than or equal to 1×10 21 cm -3 ; and / or, The carrier concentration within the P-type doped region is greater than or equal to 1 × 10⁻⁶. 18 cm -3 And less than or equal to 1×10 21 cm -3 .

8. The solar cell according to claim 7, wherein, When the first doped semiconductor portion and the second doped semiconductor portion are located on the same side of the semiconductor substrate, and the carrier concentration in the N-type doped portion is greater than or equal to 3 × 10⁻⁶, 20 cm -3 Furthermore, the carrier concentration within the P-type doped region is greater than or equal to 2 × 10⁻⁶. 19 cm -3 When the sum of the docking areas of all the conductive semiconductor portions of the solar cell along the thickness direction of the semiconductor substrate is greater than or equal to the area of ​​the back surface of the solar cell, the ratio of such ratio is greater than or equal to 1 × 10⁻⁶. -10 1. And less than or equal to 5 × 10 -4 :

1.

9. The solar cell according to claim 7, wherein, When the first doped semiconductor portion and the second doped semiconductor portion are located on the same side of the semiconductor substrate, and the carrier concentration in the N-type doped portion is less than 3 × 10⁻⁶, 20 cm -3 And / or the carrier concentration within the P-type doped region is less than 2 × 10⁻⁶. 19 cm -3 When the sum of the docking areas of all the conductive semiconductor portions of the solar cell along the thickness direction of the semiconductor substrate is greater than 5 × 10⁻⁶, the ratio of this sum to the area of ​​the back surface of the solar cell is greater than 5 × 10⁻⁶. -4 1. And less than or equal to 1×10 -2 :

1.

10. The solar cell according to any one of claims 1 to 9, wherein, At least one of the conductive semiconductor portions is located only between the first doped semiconductor portion and the second doped semiconductor portion; Alternatively, at least one of the first doped semiconductor portion and the second doped semiconductor portion is a doped semiconductor layer formed on the semiconductor substrate, and at least one of the conductive semiconductor portions is located between the first doped semiconductor portion and the second doped semiconductor portion and extends to the space between the doped semiconductor layer and the semiconductor substrate; Alternatively, at least one of the conductive semiconductor portions is a conductive semiconductor layer formed on the semiconductor substrate, and the conductive semiconductor layer is located between the first doped semiconductor portion and the second doped semiconductor portion, and extends over a portion of at least one of the first doped semiconductor portion and the second doped semiconductor portion that is away from the semiconductor substrate.

11. A photovoltaic module, comprising: The solar cell according to any one of claims 1 to 10.

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