Back contact batteries and solar modules

Abstract

This application discloses a back-contact battery and a solar module, and in the field of photovoltaic technology, aims to reduce the reverse breakdown voltage of the back-contact battery and effectively suppress leakage losses of the back-contact battery. The back-contact battery includes a semiconductor substrate, a first doped region, a second doped region, and at least one conductive semiconductor structure. The first doped region and the second doped region are alternately distributed at intervals on the non-light-receiving side of the semiconductor substrate. At least a portion of each conductive semiconductor structure is located between the first doped region and the second doped region, and only a portion of the first doped region and only a portion of the second doped region are electrically in contact with at least one conductive semiconductor structure. The width of the space region located between the first doped region and the second doped region is D1. In the direction of extension of the space region, the width of the conductive semiconductor structure is W, and 0.5 × D1 ≤ W ≤ 6 × D1.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic power, and in particular to back contact batteries and solar modules.

Background Art

[0002] A back contact battery refers to a solar cell in which there are no electrodes on the light-receiving surface of the battery cell, and both the positive and negative electrodes are arranged on the non-light-receiving surface side of the battery cell. This can reduce the shielding of the battery cell by the electrodes, increase the short-circuit current of the battery cell, and improve the energy conversion efficiency of the battery cell. Specifically, in a conventional back contact battery, two doped layers that are both located on the non-light-receiving surface side and have opposite conductivity types are separated by a discontinuous space region part, thereby reducing the reverse breakdown voltage of the back contact battery and reducing the hot spot risk from the module side.

[0003] However, in a conventional back contact battery, due to inappropriate setting of the width of the non-separated part in the space region in its extending direction, from the battery side, the leakage current of the back contact battery increases and the operating efficiency of the back contact battery deteriorates.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The object of this application is to locally electrically connect the first doped region and the second doped region of opposite conductivity types by a conductive semiconductor structure, effectively reduce the reverse breakdown voltage, and reasonably set the width of the space region of each conductive semiconductor structure in its extending direction, so as to effectively suppress leakage losses and provide a back contact battery and a solar module with high operating efficiency.

Means for Solving the Problems

[0005] To achieve the above object, in a first aspect, the present application provides a back contact battery, which includes a semiconductor substrate, a first doped region, a second doped region, and at least one conductive semiconductor structure. The first doped region and the second doped region are alternately distributed at intervals on the non-light-receiving surface side of the semiconductor substrate. The conductivity types of the first doped region and the second doped region are opposite, and the conductivity type of the conductive semiconductor structure is opposite to that of one of the first doped region and the second doped region. At least a part of each of the conductive semiconductor structures is located between the first doped region and the second doped region, and only a part of the first doped region and only a part of the second doped region are each electrically connected to at least one conductive semiconductor structure. Let the width of the space region located between the first doped region and the second doped region be D1. In the extending direction of the space region, let the width of the conductive semiconductor structure be W, and 0.5×D1≦W≦6×D1.

[0006] When the above technical solution is adopted, the first doped region and the second doped region with opposite conductivity types are alternately distributed at intervals on the non-light-receiving surface side of the semiconductor substrate. Thus, when the back contact battery is in an operating state, carriers are effectively separated, which is beneficial for the formation of photocurrent. Next, the back contact battery provided in the present application further includes at least one conductive semiconductor structure at least a part of which is located between the first doped region and the second doped region. Based on this, since each conductive semiconductor structure has conductive characteristics and the conductivity type of the conductive semiconductor structure is opposite to that of one of the first doped region and the second doped region, when the conductive semiconductor structure is electrically connected to a part of the first doped region and a part of the second doped region respectively, a local leakage point is created to electrically connect the first doped region and the second doped region, and a built-in diode with a low reverse breakdown voltage can be formed, which is beneficial for reducing the reverse breakdown voltage when the back contact battery is shielded.

[0007] Furthermore, only a portion of the first doped region and only a portion of the second doped region are electrically in contact with at least one conductive semiconductor structure. In other words, a portion of the first doped region and the corresponding portion of the second doped region are electrically in contact with at least one conductive semiconductor structure, but the remaining portion of the first doped region and the corresponding portion of the second doped region are still physically separated by an insulating trench or insulating material, thereby preventing a decrease in the operating efficiency of the back-contact battery due to the large leakage current during normal operation caused by the conductive semiconductor structure being arranged throughout between each of the first and second doped regions, and ensuring that the solar module including the back-contact battery provided in this application has high photoelectric conversion efficiency in the forward voltage region. Next, in the extension direction of the space region, the width of the conductive semiconductor structure satisfies 0.5 × D1 ≤ W ≤ 6 × D1. In this case, by adjusting the value of W, the effective electrical contact area between the conductive semiconductor structure and each of the first and second doped regions, as well as the area ratio of the effective electrical contact portion between each of the first and second doped regions in the conductive semiconductor structure to the non-light-receiving surface, can be effectively adjusted. This prevents the reduction in the reverse breakdown voltage of the back contact battery due to the arrangement of the conductive semiconductor structure from becoming small, which can result from a small sum of the effective electrical contact area between a single conductive semiconductor structure and each of the first and second doped regions, as well as the area ratio of the effective electrical contact portion between each of the first and second doped regions in all conductive semiconductor structures to the non-light-receiving surface, thus preventing the back contact battery from burning out due to localized heat concentration. Within a certain range, since smaller conductive semiconductor structures require higher etching accuracy, setting W ≥ 0.5 × D1 can further reduce the manufacturing difficulty of forming the conductive semiconductor structure on the non-light-receiving surface. Furthermore, each conductive semiconductor structure can be considered as a local recombination center located between the first doped region and the second doped region.Based on this, by keeping W within the above range, it is possible to prevent the local leakage current between the first doped region and the second doped region from becoming large due to a large value of W, and to ensure that the solar module including the back contact battery provided in this application has high photoelectric conversion efficiency in the forward voltage region.

[0008] In a possible implementation, the first doped region, the second doped region, and the conductive semiconductor structure are all formed within a semiconductor substrate, and the surfaces of the first doped region, the second doped region, and the conductive semiconductor structure that are opposite the light-receiving surface of the semiconductor substrate are all flush with the surface of the corresponding non-light-receiving region of the semiconductor substrate. In this case, the contact surface between the first doped region and the second doped region that has the opposite conductivity type to the conductive semiconductor structure and the conductive semiconductor structure includes a side effective electrical contact surface, the height of which is the side effective electrical contact surface is the side effective electrical contact height Z, and the side effective electrical contact height Z is equal to the minimum of the first depth and the second depth, the first depth is the depth of the first doped region and the second doped region that has the opposite conductivity type to the conductive semiconductor structure, and the second depth is the depth of the conductive semiconductor structure.

[0009] As a possible implementation, the first doped region and the second doped region, one of which has a conductivity type opposite to that of the conductive semiconductor structure, and the conductive semiconductor structure itself, both include a doped semiconductor layer located on the non-light-receiving surface of the semiconductor substrate. The contact surface between the first doped region and the second doped region, one of which has a conductivity type opposite to that of the conductive semiconductor structure, and the conductive semiconductor structure includes a side effective electrical contact surface, and the height of this side effective electrical contact surface is denoted as the side effective electrical contact height Z. This side effective electrical contact height Z is equal to the minimum value of the first and second thicknesses. In the direction away from the non-light-receiving surface of the semiconductor substrate in the extending direction of the side effective electrical contact surface, the first thickness is the thickness corresponding to the side effective electrical contact surface of the first doped region and the second doped region, one of which has a conductivity type opposite to that of the conductive semiconductor structure, and the second thickness is the thickness corresponding to the side effective electrical contact surface of the conductive semiconductor structure.

[0010] When the above technical solution is adopted, regardless of whether the first doped region, the second doped region, and the conductive semiconductor structure are all formed within the semiconductor substrate, or whether one of the first doped region and the second doped region has a conductivity type opposite to that of the conductive semiconductor structure, and whether the conductive semiconductor structure includes a doped semiconductor layer formed on the non-light-receiving surface of the semiconductor substrate, the size of the corresponding effective electrical contact area of ​​the conductive semiconductor structure can be adjusted by adjusting the size of the first and second thicknesses, thereby adjusting the size of the leakage current of the first and second doped regions due to the conductive semiconductor structure, which is further advantageous in balancing the corresponding reverse breakdown voltage and operating efficiency of the back-contact battery.

[0011] As a possible implementation, when the first doped region, the second doped region, and the conductive semiconductor structure all include a doped semiconductor layer formed on a non-light-receiving surface, the arrangement height of the doped semiconductor layer included in the first doped region and the second doped region on the side of the semiconductor substrate closer to the non-light-receiving surface, where the conductivity type is opposite to that of the conductive semiconductor structure, is smaller than the arrangement height of the doped semiconductor layer included in the conductive semiconductor structure on the side of the semiconductor substrate closer to the non-light-receiving surface, and a part of the side surface of the doped semiconductor layer included in the first doped region and the second doped region where the conductivity type is opposite to that of the conductive semiconductor structure is in electrical contact with the semiconductor substrate, and the other side surface of the doped semiconductor layer included in the first doped region and the second doped region where the conductivity type is opposite to that of the conductive semiconductor structure When a portion is in electrical contact with a conductive semiconductor structure, the effective electrical contact height Z on the side is equal to the thickness of the conductive semiconductor structure. Alternatively, when the doped semiconductor layer included in the first doped region and the second doped region on the side of the semiconductor substrate closer to the non-light-receiving surface has a different arrangement height from the doped semiconductor layer included in the conductive semiconductor structure, and each region of the portion corresponding to the conductive semiconductor structure on the side of the doped semiconductor layer included in the first doped region and the second doped region has a different conductivity type from the conductive semiconductor structure, then the effective electrical contact height Z on the side is equal to the thickness of the first doped region and the second doped region that has a different conductivity type from the conductive semiconductor structure.

[0012] By employing the above technical solution, the corresponding effective electrical contact area of ​​the conductive semiconductor structure can be precisely adjusted according to the differences in effective electrical contact height on the sides in various cases, and the magnitude of the leakage current in the first doped region and the second doped region by the conductive semiconductor structure can be precisely adjusted, thereby improving the yield of back contact batteries.

[0013] The possible implementation is 0.00005 mm ≤ Z ≤ 0.002 mm.

[0014] When the above technical solution is adopted, in practical use, considering the carrier isolation capability and the amount of consumable material used, the first and second doped regions included in the back contact battery usually have a reasonable thickness range. Furthermore, the magnitude of the lateral effective electrical contact height Z affects the corresponding effective electrical contact area of ​​the conductive semiconductor structure, and thus affects the magnitude of the leakage current in the first and second doped regions that conduct locally through a single conductive semiconductor structure. In this case, by keeping the lateral effective electrical contact height within the above range, it is possible to prevent a deterioration in the balance between the hot spot risk of the back contact battery and the operating efficiency during normal operation, which can occur due to the corresponding effective electrical contact area of ​​the conductive semiconductor structure being too large or too small. It is also possible to prevent an increase in the amount of manufacturing material used for the conductive semiconductor structure due to a large lateral effective electrical contact height, which is advantageous in suppressing the manufacturing cost of the back contact battery.

[0015] As a possible implementation, in the non-light-receiving side of the semiconductor substrate, the height of the doped semiconductor layer included in the first doped region and the second doped region, which has a conductivity type opposite to that of the conductive semiconductor structure, is smaller than the height of the doped semiconductor layer included in the other of the first doped region and the second doped region, and a part of the side surface of the doped semiconductor layer included in the first doped region and the second doped region, which has a conductivity type opposite to that of the conductive semiconductor structure, is in electrical contact with the semiconductor substrate, and the other part of the side surface of the doped semiconductor layer included in the first doped region and the second doped region, which has a conductivity type opposite to that of the conductive semiconductor structure, is in electrical contact with the conductive semiconductor structure. In this case, in the thickness direction of the semiconductor substrate, the difference between the surface height of the region on the non-light-receiving side corresponding to the conductive semiconductor structure and the surface height of the region on the first doped region and the second doped region, which corresponds to the doped semiconductor layer included in the one of the first doped region and the second doped region, which has a conductivity type opposite to that of the conductive semiconductor structure, is 0.4 μm or more and 2 μm or less.

[0016] When the above technical solution is adopted, the case in which the conductivity type of the doped semiconductor layer included in the first doped region and the conductive semiconductor structure are opposite will be explained as an example. When forming the doped semiconductor layer included in the first doped region, the manufacturing material for the doped semiconductor layer included in the first doped region is less likely to fill the corners due to height differences. As a result, it becomes difficult for the doped semiconductor layer included in the first doped region to make complete contact with each part of the surface of the semiconductor substrate (or the semiconductor substrate and the conductive semiconductor structure) at the corners. Therefore, by keeping the difference between the surface height of the region corresponding to the non-light-receiving conductive semiconductor structure and the surface height of the region of the doped semiconductor layer whose conductivity type is opposite to that of the conductive semiconductor structure within the above range, the portion of the doped semiconductor layer included in the first doped region that is filled at the corners can be shifted away from the sidewall of the conductive semiconductor structure whose conductivity type is opposite to that of the conductive semiconductor structure itself, thereby ensuring that there is a large effective electrical contact area between the conductive semiconductor structure and the first doped region whose conductivity type is opposite to that of the conductive semiconductor structure itself. When the conductivity type of the doped semiconductor layer included in the second doped region and the conductive semiconductor structure are opposite, the corresponding beneficial effects are the same as those described above and will not be explained again here.

[0017] Possible implementations are those where 0.5 × D1 ≤ W ≤ 3 × D1.

[0018] When the above technical solution is adopted, in practical use, the width in the extending direction of the space region of the conductive semiconductor structure affects not only the effective electrical contact area between the conductive semiconductor structure and each of the first doped region and the second doped region, but the thickness of the conductive semiconductor structure (and, if the second conductive semiconductor portion of the conductive semiconductor structure is further electrically in contact with the portion of the conductive semiconductor structure located on the first doped region and / or the portion located on the second doped region, if it is located on the semiconductor substrate opposite to the first doped region) may also affect the size of the effective electrical contact area. If the placement heights of the doped semiconductor layers included in the first doped region and the second doped region are different on the semiconductor substrate, and one of them has a smaller placement height than the placement height of the conductive semiconductor structure on the semiconductor substrate, and the one of them has a conductivity type opposite to that of the conductive semiconductor structure, then it can be understood that the greater the thickness of the conductive semiconductor structure, the greater the effective electrical contact area. In this case, by keeping the width W in the extending direction of the space region of the conductive semiconductor structure within the above range, a predetermined placement space can be secured for at least the thickness range of the conductive semiconductor structure and / or the placement width range in the case of electrical contact. This prevents the effective electrical contact area from becoming large due to the thickness, width W of the conductive semiconductor structure and the placement width in the case of electrical contact being large, thereby preventing a reduction in the leakage loss of the back contact battery and ensuring that the back contact battery has relatively high operating efficiency.

[0019] In possible realizations, both the first and second doped regions contain multiple striped doped regions. The striped doped regions included in the first doped region and the striped doped regions included in the second doped region are distributed parallel to each other with spacing between them. At least a portion of the conductive semiconductor structure is located between two adjacent striped doped regions of opposite conductivity types.

[0020] In a possible implementation, when the first doped region and the second doped region are distributed alternately at intervals in a comb-like pattern, both the first and second doped regions include multiple striped doped regions and at least one connecting region, the striped doped regions included in the first doped region and the striped doped regions included in the second doped region are distributed alternately in parallel and at intervals, each connecting region is electrically connected to a corresponding striped doped region of the same conductivity type as itself, and the direction of extension of the connecting region is different from the direction of extension of the striped doped regions. At least a portion of at least one conductive semiconductor structure is located between two adjacent stripe-shaped doped regions, each belonging to a first doped region and a second doped region, and the width direction of the conductive semiconductor structure is parallel to the direction of extension of the stripe-shaped doped regions, and / or at least a portion of at least one conductive semiconductor structure is located between one stripe-shaped doped region included in one of the first doped region and the second doped region and an adjacent connecting region included in the other of the first doped region and the second doped region, and the width direction of the conductive semiconductor structure is parallel to the distribution direction of the stripe-shaped doped regions of the opposite conductivity type.

[0021] When the above technical solution is adopted, if the first doped region and the second doped region are distributed alternately with spacing between them in a comb-like pattern, there are at least three selectable configurations for the arrangement position on the non-light-receiving surface side of each conductive semiconductor structure. This makes it easier to select an appropriate configuration according to the requirements of different application scenarios, thereby improving the applicability of the back contact battery provided in this application to different application scenarios.

[0022] In a possible implementation, if at least a portion of the conductive semiconductor structure belongs to a first doped region and a second doped region, respectively, and is located between two adjacent striped doped regions, then in the first doped region, the width of the striped doped region in contact with the conductive semiconductor structure is D2, and in the second doped region, the width of the striped doped region in contact with the conductive semiconductor structure is D3. Furthermore, in the distribution direction of the striped doped regions of the opposite conductivity type, the length of the conductive semiconductor structure is D, and D1 ≤ D ≤ D1 + D2 + D3.

[0023] When the above technical solution is adopted, once the layout of the back contact battery is determined, D1, D2, and D3 become fixed values. Based on this, if at least a portion of the conductive semiconductor structure belongs to the first doped region and the second doped region respectively and is located between two adjacent striped doped regions, then if D is equal to D1, the conductive semiconductor structure of the opposite conductivity type and located between two adjacent striped doped regions can electrically contact the two adjacent striped doped regions of the opposite conductivity type in the arrangement direction of the striped doped regions of the opposite conductivity type, thereby ensuring that the first doped region and the second doped region are electrically connected via the conductive semiconductor structure. At the same time, the area of ​​the orthographic projection on the non-light-receiving side of the conductive semiconductor structure can be precisely adjusted, ensuring that the corresponding hot spot risk and operating efficiency during normal operation of the back contact battery both accurately meet the operating requirements. Next, the value of D may be greater than D1 and less than or equal to D1 + D2 + D3. In this case, the conductive semiconductor structure can be located not only between two adjacent stripe-shaped doped regions of opposite conductivity types, but also on at least one of two adjacent stripe-shaped doped regions of opposite conductivity types. This prevents the requirements for etching accuracy from becoming too strict in order to obtain a conductive semiconductor structure located only between two adjacent stripe-shaped doped regions of opposite conductivity types, thereby reducing the difficulty of etching. Furthermore, when the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, the size of the effective electrical contact area can be adjusted by adjusting the value of D. This is advantageous for balancing the reverse breakdown voltage and leakage loss of the back-contact battery, and is beneficial for the back-contact battery to have good operating performance.

[0024] Possible implementations include,

number

[0025] When the above technical solution is adopted, the carriers collected by the first doped region and the second doped region need to be guided out via an electrode structure that is in ohmic contact with itself. Based on this, in the width direction of the striped doped region, a portion of the striped doped region contained within the first doped region and the second doped region in its extending direction needs to be in direct ohmic contact with the electrode structure, and this ohmic contact region occupies a certain width. In this case,

number

[0026] In a possible implementation, when at least a portion of the conductive semiconductor structure is located between a striped doped region included in one of the first and second doped regions and an adjacent connecting region included in the other of the first and second doped regions, the width of the connecting region belonging to one of the first and second doped regions and in contact with the conductive semiconductor structure is W1, and the length of the striped doped region belonging to the other of the first and second doped regions and in contact with the conductive semiconductor structure is W2. Furthermore, in the width direction of the space region, the length of the conductive semiconductor structure is D, and D1 ≤ D ≤ D1 + W1 + W2.

[0027] When the above technical solution is adopted, once the layout of the back contact battery is determined, D1, W1, and W2 become fixed values. Based on this, if at least a portion of the conductive semiconductor structure is located between one stripe-shaped doped region included in one of the first and second doped regions and an adjacent connection region included in the other of the first and second doped regions, if D is equal to D1, it enables the conductive semiconductor structure located between the adjacent stripe-shaped doped region and connection region, which is of the opposite conductivity type, to electrically contact the adjacent stripe-shaped doped region and connection region, respectively, which are of the opposite conductivity type in the arrangement direction of the first and second doped regions, thereby ensuring that the first and second doped regions are electrically connected via the conductive semiconductor structure. At the same time, it is also possible to precisely adjust the orthographic area on the non-light-receiving side of the conductive semiconductor structure, ensuring that the corresponding hot spot risk and operating efficiency during normal operation of the back contact battery both accurately meet the operating requirements. Next, the value of D may be greater than D1 and less than or equal to D1 + W1 + W2. In this case, the conductive semiconductor structure can be located not only between adjacent stripe-doped regions and connection regions of the opposite conductivity type, but also on at least one of adjacent stripe-doped regions and connection regions of the opposite conductivity type. This prevents the requirements for etching accuracy from becoming too strict in order to obtain a conductive semiconductor structure located only between adjacent stripe-doped regions and connection regions of the opposite conductivity type, thereby reducing the difficulty of etching. Furthermore, when the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the semiconductor substrate opposite to the first doped region and / or the second doped region, the size of the effective electrical contact area can be adjusted by adjusting the value of D. This is advantageous for balancing the reverse breakdown voltage and leakage loss of the back-contact battery, and is advantageous for the back-contact battery to have good operating performance.

[0028] Possible implementations include,

number

[0029] When the above technical solution is adopted, the carriers collected by the first doped region and the second doped region need to be guided out via an electrode structure that is in ohmic contact with itself. Based on this, in the direction of extension of the striped doped region, a portion of the striped doped region contained within the first doped region and the second doped region in that direction needs to be in direct ohmic contact with the electrode structure, and this ohmic contact region occupies a certain length. In this case,

number

[0030] As a possible implementation, the area of ​​the orthographic projection on the non-photosensitive side of the portion located between the first doped region and the second doped region of at least one conductive semiconductor structure is S1, the area of ​​the non-photosensitive surface is S2, and the ratio of S1 to S2 is 8.5 × 10⁻⁶. -7 % or more 6.67 × 10 -1 It is less than %.

[0031] By adopting the above technical solution, the ratio of S1 to S2 is kept within the above range, which prevents a reduction in the reverse breakdown voltage of the back contact battery due to the arrangement of the conductive semiconductor structure caused by a small S1, prevents the back contact battery from burning out due to localized heat concentration, and effectively reduces the risk of hot spots in the solar module including the back contact battery provided in this application. It also prevents the requirements for etching accuracy from becoming too strict in order to form a small conductive semiconductor structure, and reduces the difficulty of etching. Furthermore, it prevents a large leakage current during normal operation of the back contact battery caused by a large S1, and further ensures that the solar module including the back contact battery provided in this application has high photoelectric conversion efficiency in the forward voltage region.

[0032] As a possible implementation, the back-contact battery includes a plurality of conductive semiconductor structures. Adjacent conductive semiconductor structures are spaced apart. In this case, it is possible to prevent a large local leakage current from occurring between the first doped region and the second doped region due to contact between adjacent different conductive semiconductor structures.

[0033] Possible implementations include, if the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures included in the back contact battery is between 30 and 8000, or if the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures included in the back contact battery is between 30 / N and 8000 / N, where N is a positive integer of 2 or more.

[0034] When the above technical solution is adopted, it can be understood that if the size of each conductive semiconductor structure is constant, the more conductive semiconductor structures formed on the non-light-receiving surface side there are, the larger the total area of ​​the orthographic projection of the conductive semiconductor structures on the non-light-receiving surface side will be. Next, within a certain range, as the number of conductive semiconductor structures increases, the corresponding reverse breakdown voltage of the back contact battery gradually decreases, but beyond the corresponding range, even if more conductive semiconductor structures are placed on the non-light-receiving surface side, the corresponding reverse breakdown voltage of the back contact battery changes only slightly, and eventually stops changing. When the number of conductive semiconductor structures increases to a large range, the operating efficiency of the back contact battery decreases as the leakage current increases. Based on this, if the back contact battery is an integrated back contact battery, setting the number of conductive semiconductor structures included in the back contact battery to between 30 and 8000 prevents the reduction in the corresponding reverse breakdown voltage of the back contact battery from becoming small due to the small number of conductive semiconductor structures, and ensures that the hot spot risk of the back contact battery is reduced within the range of operating requirements. Furthermore, it is possible to prevent a decrease in the operating efficiency of the solar module including the back contact battery provided in this application due to the arrangement of many conductive semiconductor structures. The beneficial effects of having 30 to 8000 conductive semiconductor structures in the back contact battery when the back contact battery is a 1 / N split back contact battery can be explained by referring to the analysis of the beneficial effects of having 30 to 8000 conductive semiconductor structures in the back contact battery when the back contact battery is an integrated back contact battery, as described above, and will not be explained again here.

[0035] As a possible implementation, the sum of the orthographic areas on the non-photosensitive side of the portion located between the first doped region and the second doped region of all conductive semiconductor structures is S3, the area of ​​the non-photosensitive surface is S2, and the ratio of S3 to S2 is between 0.002% and 20%.

[0036] By adopting the above technical solution, by keeping the ratio of S3 to S2 within the above range, it is possible to prevent the orthographic projection area on the non-light-receiving side of a single conductive semiconductor structure from becoming smaller and / or the number of conductive semiconductor structures arranged on the non-light-receiving side from becoming smaller due to a small ratio of S3 to S2, thereby ensuring that the reverse breakdown voltage of the back contact battery is reduced to a range that satisfies the operating requirements by arranging the conductive semiconductor structures in a reasonable number and with a reasonable orthographic projection area. Furthermore, it is also possible to prevent the operating efficiency of the solar module, including the back contact battery, from becoming lower in the forward voltage region due to a large ratio of S3 to S2, which results in a large orthographic projection area on the non-light-receiving side of a single conductive semiconductor structure and / or an increase in the number of conductive semiconductor structures arranged on the non-light-receiving side.

[0037] One possible implementation is that the orthographic projection areas on the non-photosensitive side of different conductive semiconductor structures are equal.

[0038] When the above technical solution is adopted, having equal orthographic projection areas on the non-light-receiving side of different conductive semiconductor structures is advantageous for making the magnitude of the corresponding leakage currents the same after the first doped region and the second doped region are electrically connected to different conductive semiconductor structures, is advantageous for making the reverse breakdown voltages of the built-in diodes located in different regions between the first doped region and the second doped region equal, prevents the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded, and further reduces the risk of hot spots in solar modules including the back contact battery provided in this application.

[0039] In a possible implementation, the different conductive semiconductor structures are uniformly distributed on the non-light-receiving side. In this case, it is advantageous to equalize the reverse breakdown voltage of the built-in diode formed after arranging the conductive semiconductor structures between different regions of the first doped region and corresponding regions of the second doped region, preventing the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded, and further reducing the risk of hot spots in solar modules including the back contact battery provided in this application.

[0040] In a possible implementation, different conductive semiconductor structures are distributed in a matrix on the non-light-receiving side. Adjacent rows of the matrix-distributed conductive semiconductor structures are either aligned or staggered. In this case, the distribution of different conductive semiconductor structures on the non-light-receiving side is regular, and there are two distribution modes between adjacent rows of the matrix-distributed conductive semiconductor structures: aligned and staggered. This is advantageous in reducing the difficulty of manufacturing the conductive semiconductor structures, while also being advantageous in uniformly distributing the conductive semiconductor structures on the non-light-receiving side, and further prevents the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded.

[0041] As a possible implementation, when adjacent rows of conductive semiconductor structures distributed in a matrix are arranged in a staggered pattern, the displacement distance between two adjacent rows of conductive semiconductor structures is equal to half the distance between the geometric centers of two adjacent conductive semiconductor structures within the same row. In this case, it is advantageous to make the distribution density between different regions of the first doped region and the corresponding regions of the second doped region of the conductive semiconductor structure approximately the same, and prevents the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded due to a long region physically separated between the first and second doped regions by an insulating trench or insulating material.

[0042] Possible implementations include the conductive semiconductor structure and the first doped region having the same conductivity type and being integrally continuous, or the conductive semiconductor structure and the second doped region having the same conductivity type and being integrally continuous.

[0043] When the above technical solution is adopted, in the actual manufacturing process, the conductive semiconductor structure can be manufactured simultaneously with the manufacturing of the first doped region or the second doped region using the same process. For example, when manufacturing the first doped region (or second doped region), the first doped region (or second doped region) and the conductive semiconductor structure can be obtained by selectively etching the doped semiconductor material layer integrally formed on the non-light-receiving surface side. Based on this, when the conductive semiconductor structure and the first doped region or second doped region are integrally continuous, the conductive semiconductor structure and the first doped region (or second doped region) can be manufactured based on the same doped semiconductor material layer. This reduces the manufacturing cost of back contact batteries, eliminates the need to separately form the conductive semiconductor structure by deposition and etching processes, simplifies the back contact battery manufacturing flow, and improves the manufacturing efficiency of back contact batteries.

[0044] In a possible implementation, at least one of the first doped region, the second doped region, and the conductive semiconductor structure includes a doped semiconductor layer located on the non-photosensitive surface of the semiconductor substrate, and the back-contact battery further includes a passivation layer located between the semiconductor substrate and the doped semiconductor layer. In this case, the passivation layer can passivate the corresponding region of the non-photosensitive surface of the semiconductor substrate, thereby reducing the carrier recombination rate.

[0045] Possible realizations include a doped semiconductor layer comprising at least one of a doped polycrystalline silicon layer, a doped single-crystal silicon layer, a doped amorphous silicon layer, a doped microcrystalline silicon layer, and a doped nanocrystalline silicon layer, and / or a passivation layer comprising a tunnel passivation layer or an intrinsic amorphous silicon layer.

[0046] In a second aspect, the present application provides a solar module including a solar cell provided in the first aspect and various realizations thereof.

[0047] The beneficial effects of the second aspect and its various implementations in this application can be found by referring to the analysis of the beneficial effects of the first aspect and its various implementations, and will not be described again here.

[0048] In a third aspect, the present application further provides a method for manufacturing a back-contact battery, the method for manufacturing a back-contact battery comprising the following steps: First, a semiconductor substrate is provided. Next, a first doped region and a second doped region are formed on the non-light-receiving side of the semiconductor substrate, the first doped region and the second doped region are alternately distributed at intervals on the non-light-receiving side of the semiconductor substrate, and the conductivity types of the first doped region and the second doped region are opposite. Next, at least one conductive semiconductor structure is formed on the non-light-receiving side of the semiconductor substrate, the conductivity type of the conductive semiconductor structure is opposite to the conductivity type of one of the first doped region and the second doped region, at least a portion of each conductive semiconductor structure is located between the first doped region and the second doped region, only a portion of the first doped region and only a portion of the second doped region are electrically in contact with at least one conductive semiconductor structure, the width of the space region located between the first doped region and the second doped region is D1, the width of the conductive semiconductor structure in the direction of extension of the space region is W, and 0.5 × D1 ≤ W ≤ 6 × D1.

[0049] In a possible implementation, the non-light-receiving surface of the semiconductor substrate has a first region and a second region distributed alternately at intervals, and a space region located between the first region and the adjacent second region. In this case, forming the first doped region, the second doped region and the conductive semiconductor structure on the non-light-receiving surface side of the semiconductor substrate includes the following steps: Forming the first doped region in the first region. Next, forming a doped semiconductor material layer integrally in the first doped region, the space region and the second region. Next, selectively etching the doped semiconductor material layer to remove portions of the doped semiconductor material layer corresponding to a part of the first doped region and a part of the space region. The selectively etched doped semiconductor material layer forms a second doped region located in the second region and at least one conductive semiconductor structure.

[0050] In a possible implementation, the non-light-receiving surface of the semiconductor substrate has a first region and a second region distributed alternately at intervals, and a space region located between the first region and the adjacent second region. In this case, forming the first doped region, the second doped region and the conductive semiconductor structure on the non-light-receiving surface side of the semiconductor substrate includes the following steps: Forming the second doped region in the first region. Next, forming a doped semiconductor material layer integrally in the second doped region, the space region and the second region. Next, selectively etching the doped semiconductor material layer to remove portions of the doped semiconductor material layer corresponding to a part of the second doped region and a part of the space region. The selectively etched doped semiconductor material layer forms the first doped region and the conductive semiconductor structure located in the second region.

[0051] The beneficial effects of the third aspect of this application and its various implementations can be found by referring to the analysis of the beneficial effects of the corresponding implementations in the first aspect, and will not be repeated here. [Brief explanation of the drawing]

[0052] The drawings described herein are provided for further understanding of this application and constitute part of this application. The schematic embodiments and descriptions herein are for interpretive purposes only and do not unduly limit this application.

[0053] [Figure 1] This diagram shows a schematic representation of the area range of selective etching in related technologies, and a schematic representation of the distribution of the selectively etched first doped region and second doped region on the non-light-receiving surface side. [Figure 2] This is a schematic diagram of the distribution relationship between the first doped region and the second doped region on the non-light-receiving surface side in the back-contact battery provided in the embodiment of this application. [Figure 3] This is a schematic diagram of the first distribution of conductive semiconductor structures between two adjacent stripe-shaped doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 4] This is a schematic diagram of the first distribution of conductive semiconductor structures between adjacent stripe-doped regions and connection regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 5] This is a first longitudinal schematic view of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 6] This is a second schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 7] This is a schematic diagram of a second distribution of conductive semiconductor structures between two adjacent stripe-shaped doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 8] This is a schematic diagram of a third distribution of conductive semiconductor structure between two adjacent stripe-doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 9]This is a schematic diagram of a fourth distribution of conductive semiconductor structures between two adjacent stripe-shaped doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 10] This is a schematic diagram of a second distribution of conductive semiconductor structures between adjacent stripe-doped regions and connection regions, which have opposite conductivity types, in a back-contact battery provided in an embodiment of this application. [Figure 11] This is a schematic diagram of the selective etching region range and the distribution of the selectively etched first doped region, second doped region, and conductive semiconductor structure on the non-light-receiving surface side in the embodiment of this application. [Figure 12] This is a third schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 13] This is a fourth schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 14] This is a fifth schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 15] This is a sixth schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 16] This is a seventh schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 17] This is an eighth schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 18] This is a ninth schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 19] This is a schematic longitudinal section of a tenth substructure of a back-contact battery provided in an embodiment of this application. [Figure 20] This is a schematic longitudinal section of an eleventh substructure of a back-contact battery provided in an embodiment of this application. [Figure 21]This is a twelfth schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 22] This is a schematic longitudinal section of a thirteenth substructure of a back-contact battery provided in an embodiment of this application. [Figure 23] This is a schematic longitudinal section of a 14th substructure of a back-contact battery provided in an embodiment of this application. [Figure 24] This is a schematic longitudinal section of a 15th substructure of a back-contact battery provided in an embodiment of this application. [Figure 25] This is a schematic longitudinal section of a 16th substructure of a back-contact battery provided in an embodiment of this application. [Figure 26] This is a schematic longitudinal section of the 17th substructure of a back-contact battery provided in an embodiment of this application. [Figure 27] This is a schematic longitudinal section of a substructure of a back-contact battery provided in an embodiment of this application. [Figure 28] This is a schematic longitudinal section of a 19th substructure of a back-contact battery provided in an embodiment of this application. [Figure 29] This is a 20th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 30] This is a schematic longitudinal section of a 21st substructure of a back-contact battery provided in an embodiment of this application. [Figure 31] This is a 22nd schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 32] This is a 23rd schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 33] This is a 24th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 34] This is a 25th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 35] This is a 26th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 36] This is a schematic longitudinal section of the 27th substructure of a back-contact battery provided in an embodiment of this application. [Figure 37] This is a 28th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 38] This is a 29th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 39] This is a 30th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 40] This is a schematic longitudinal section of a 31st substructure of a back-contact battery provided in an embodiment of this application. [Figure 41] This is a 32nd schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 42] This is a schematic longitudinal section of a 33rd substructure of a back-contact battery provided in an embodiment of this application. [Figure 43] This is a 34th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 44] This is a 35th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 45] This is a 36th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 46] This is a schematic longitudinal section of the 37th substructure of a back-contact battery provided in an embodiment of this application. [Figure 47] This is a schematic longitudinal section of the 38th substructure of a back-contact battery provided in an embodiment of this application. [Figure 48] This is a schematic longitudinal section of the 39th substructure of a back-contact battery provided in an embodiment of this application. [Figure 49] This is a 40th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 50] This is a schematic diagram of the first distribution of the conductive semiconductor structure on the non-light-receiving surface side in the back-contact battery provided in the embodiment of this application. [Figure 51] This is a schematic diagram of the second distribution of the conductive semiconductor structure on the non-light-receiving surface side in the back-contact battery provided in the embodiment of this application. [Figure 52] This diagram shows the relationship between the number of conductive semiconductor structures and the leakage current, hot spot temperature, and reverse breakdown voltage in the back contact battery provided in the embodiment of this application, where W is 200 μm and D1 is 100 μm. [Figure 53] This diagram shows the relationship between the number of conductive semiconductor structures and the change in operating efficiency in the back-contact battery provided in the embodiment of this application, where W is 200 μm and D1 is 100 μm. [Figure 54] This diagram shows the relationship between the number of conductive semiconductor structures and the leakage current, hot spot temperature, and reverse breakdown voltage when W is 680 μm and D1 is 100 μm. [Figure 55] This diagram shows the relationship between the number of conductive semiconductor structures and the change in operating efficiency when W is 680 μm and D1 is 100 μm. [Figure 56] This is a graph showing the relationship between reverse current and reverse voltage corresponding to Examples 1 to 4 in the embodiments of this application. [Figure 57] This is a schematic diagram of a fifth distribution of conductive semiconductor structure between two adjacent stripe-shaped doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 58] This is a schematic diagram of a sixth distribution of conductive semiconductor structure between two adjacent stripe-doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 59]This is a schematic diagram of a seventh distribution of conductive semiconductor structures between two adjacent stripe-doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 60] This is a schematic diagram of an eighth distribution of conductive semiconductor structures between two adjacent stripe-doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 61] This is a schematic diagram of the ninth distribution of the conductive semiconductor structure between two adjacent stripe-doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 62] This is a schematic diagram of a tenth distribution of conductive semiconductor structures between two adjacent stripe-doped regions of opposite conductivity types in a back-contact battery provided in an embodiment of this application. [Figure 63] This is a schematic longitudinal section of the 41st substructure of a back-contact battery provided in an embodiment of this application. [Figure 64] This is a 42nd schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 65] This is a schematic longitudinal section of the 43rd substructure of a back-contact battery provided in an embodiment of this application. [Figure 66] This is a 44th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 67] This is a 45th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Figure 68] This is a 46th schematic longitudinal section of a substructure in a back-contact battery provided in an embodiment of this application. [Modes for carrying out the invention]

[0054] Examples of the present disclosure will be described below with reference to the drawings. However, it should be understood that these descriptions are illustrative only and are not intended to limit the scope of the present disclosure. Furthermore, in order to avoid unnecessary confusion of the concepts of the present disclosure, descriptions of known structures and technologies will be omitted in the following description.

[0055] The drawings show schematic diagrams of various structures according to embodiments of the present disclosure. These drawings are not drawn to scale, and some details may be enlarged or omitted for clarity. The shapes of the various regions and layers shown in the drawings, and their relative sizes and positions, are illustrative only, and in practice, variations may occur due to manufacturing tolerances or technical limitations, and those skilled in the art may design regions / layers with different shapes, sizes, and relative positions according to actual requirements.

[0056] In the context of this disclosure, when a layer / element is said to be located "on top of" another layer / element, this layer / element may be located directly on top of this other layer / element, or an intermediate layer / element may exist between them. Also, if a layer / element is located "on top of" another layer / element in a certain orientation, reversing the orientation may cause this layer / element to be located "below" this other layer / element. To make the technical problem, technical solution and beneficial effects that this application seeks to solve clearer and easier to understand, this application will be described in more detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are for interpretation purposes only and are not intended to limit this application.

[0057] Furthermore, the terms “first” and “second” are merely descriptive and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features being described. Therefore, features designated as “first” and “second” may include one or more such features explicitly or implicitly. In this description, “multiple” means two or more unless explicitly and specifically limited. “Several” means one or more unless explicitly and specifically limited.

[0058] In the description of this application, unless otherwise explicitly stated and limited, the terms “attachment,” “connection,” and “connection” should be understood broadly, for example, that connections may be fixed, detachable, or integral. Connections may also be mechanical or electrical. Connections may be direct, indirect via an intermediate medium, internal communication between two elements, or a mutual interaction between two elements. Those skilled in the art will understand the specific meaning of these terms in this application depending on the specific context.

[0059] The hot spot effect refers to a localized temperature rise in a solar module caused by quality issues such as damage to solar cells, microcracks, or faulty soldering, or by obstructions such as shadows, bird droppings, or dust on the solar cells. These problems cause the affected solar cells to act as a load, consuming energy from other solar cells connected in series with it. Within a certain range, the higher the reverse breakdown voltage of the solar cell, the higher the temperature that occurs after a hot spot problem occurs.

[0060] As shown in Figure 1, in conventional back-contact batteries, two doped regions, both located on the non-light-receiving side and with opposite conductivity types, are completely separated by a space region. This reduces leakage from the battery side and increases the operating efficiency of a single back-contact battery. However, from the module side, because the two doped layers with opposite conductivity types are completely separated, the back-contact battery has a high reverse breakdown voltage. As a result, solar modules containing conventional back-contact batteries have a higher risk of hot spots during actual operation.

[0061] To address the above technical challenges, a person skilled in the art can change the continuous insulating trench located in the space region of the original back-contact battery to a discontinuous insulating trench, thereby electrically connecting two doped layers of opposite conductivity through the separation of the insulating trenches, and consequently reducing the reverse breakdown voltage of the back-contact battery and the risk of hot spots during actual operation of a solar module including a conventional back-contact battery.

[0062] However, in conventional back-contact batteries, the width setting of the unseparated portion within the space region in its extension direction is inappropriate. From the battery's perspective, this results in a large leakage current in the back-contact battery and poor operating efficiency.

[0063] To solve the above technical problems, in the first aspect, the embodiment of this application provides a back contact battery. This back contact battery may be an integrated back contact battery or a 1 / N divided back contact battery. By dividing an integrated back contact battery by a division ratio N, N 1 / N divided back contact batteries can be obtained. The division ratio N of the divided back contact battery may be any positive integer of 2 or more.

[0064] Specifically, as shown in Figures 2 to 4, the back-contact battery provided in the embodiment of this application includes a semiconductor substrate (not shown), a first doped region 11, a second doped region 12, and at least one conductive semiconductor structure 13. The first doped region 11 and the second doped region 12 are alternately distributed at intervals on the non-light-receiving side of the semiconductor substrate. The conductivity types of the first doped region 11 and the second doped region 12 are opposite, and the conductivity type of the conductive semiconductor structure 13 is opposite to the conductivity type of one of the first doped region 11 and the second doped region 12. At least a portion of each conductive semiconductor structure is located between the first doped region 11 and the second doped region 12, and only a portion of the first doped region 11 and only a portion of the second doped region 12 are electrically in contact with at least one conductive semiconductor structure 13. The width of the space region located between the first doped region 11 and the second doped region 12 is D1. In the extension direction of the space region, the width of the conductive semiconductor structure 13 is W, and 0.5 × D1 ≤ W ≤ 6 × D1.

[0065] It should be explained that the extension direction of the space region is the direction parallel to the non-photosensitive surface of the semiconductor substrate and perpendicular to the width of the space region.

[0066] When the above technical solution is adopted, as shown in Figure 2, the first doped region 11 and the second doped region 12 of opposite conductivity types are alternately distributed with a gap between them on the non-photoreceiving side of the semiconductor substrate, thereby effectively separating carriers when the back contact battery is in operation, which is advantageous for the formation of photocurrent. Next, as shown in Figures 3 and 4, the back contact battery provided in the embodiment of this application further includes at least one conductive semiconductor structure 13, at least a portion of which is located between the first doped region and the second doped region. Based on this, each conductive semiconductor structure 13 has conductive properties, and the conductivity type of the conductive semiconductor structure 13 is opposite to the conductivity type of one of the first doped region 11 and the second doped region 12. Therefore, when the conductive semiconductor structure 13 is in electrical contact with a part of the first doped region and a part of the second doped region, respectively, it is possible to create a localized leak point that electrically connects the first doped region and the second doped region, forming a built-in diode with a low reverse breakdown voltage, which is advantageous in that the reverse breakdown voltage is low when the back contact battery is shielded. In addition, only a part of the first doped region and only a part of the second doped region are in electrical contact with at least one conductive semiconductor structure 13. In other words, a portion of the first doped region and a corresponding portion of the second doped region are electrically in contact with at least one conductive semiconductor structure 13, but the remaining portion of the first doped region and the corresponding portion of the second doped region are still physically separated by an insulating trench or insulating material, thereby preventing a decrease in the operating efficiency of the back-contact battery due to the large leakage current during normal operation of the back-contact battery caused by the conductive semiconductor structure 13 being arranged throughout between each of the first and second doped regions, and ensuring that the solar module including the back-contact battery provided in the embodiment of this application has a high photoelectric conversion efficiency in the forward voltage region.Furthermore, in the extension direction of the space region, the width of the conductive semiconductor structure 13 satisfies 0.5 × D1 ≤ W ≤ 6 × D1. In this case, by adjusting the value of W, the effective electrical contact area between the conductive semiconductor structure 13 and each of the first doped region and the second doped region, as well as the area ratio of the effective contact portion between each of the first doped region and the second doped region in the conductive semiconductor structure 13 to the non-light-receiving surface side, can be effectively adjusted. This prevents the reduction in the reverse breakdown voltage of the back contact battery due to the arrangement of the conductive semiconductor structure 13 from becoming small due to a small effective electrical contact area between a single conductive semiconductor structure 13 and each of the first doped region and the second doped region, and a small total area ratio of the effective contact portions between each of the first doped region and the second doped region in all conductive semiconductor structures 13 to the non-light-receiving surface side, thereby preventing the back contact battery from burning out due to localized heat concentration. Within a certain range, the smaller the size of the conductive semiconductor structure 13, the higher the etching accuracy required. Therefore, by setting W ≥ 0.5 × D1, the manufacturing difficulty of forming the conductive semiconductor structure 13 on the non-light-receiving surface side can be further reduced. In addition, each conductive semiconductor structure 13 can be considered as a local recombination center located between the first doped region and the second doped region. Based on this, by keeping W within the above range, it is possible to prevent the local leakage current between the first doped region and the second doped region from becoming large due to a large value of W, and to ensure that the solar module including the back contact battery provided in the embodiment of this application has a high photoelectric conversion efficiency in the forward voltage region.

[0067] In practical applications, the semiconductor substrate may be a substrate made of any of the following semiconductor materials: a silicon substrate, a germanium silicon substrate, a germanium substrate, or a gallium arsenide substrate.

[0068] With respect to the first and second doped regions, from the viewpoint of conductivity type, the first doped region may be an N-type doped region, in which case the second doped region is a P-type doped region. Alternatively, the first doped region may be a P-type doped region, in which case the second doped region is an N-type doped region. Next, the embodiments of this application do not specifically limit the thickness (or depth) H1 of the first doped region and the thickness (or depth) H2 of the second doped region, as long as they are applicable to the back contact battery provided in the embodiments of this application.

[0069] Furthermore, from the viewpoint of formation location, both the first doped region and the second doped region may be formed within the non-light-receiving surface of the semiconductor substrate. In this case, the surface of the semiconductor substrate opposite to the light-receiving surface of the first doped region and the surface of the semiconductor substrate opposite to the light-receiving surface of the second doped region may be flush with the non-light-receiving surface of the semiconductor substrate, or there may be a difference in height between them. The depth of the first doped region and the second doped region refers to the doping depth corresponding to them. Next, the material of both the first doped region and the second doped region is the same as the material of the semiconductor substrate.

[0070] Alternatively, the first doped region and / or the second doped region may both include a doped semiconductor layer formed on the non-light-receiving surface of the semiconductor substrate. In this case, the material of the doped semiconductor layer may be any semiconductor material such as silicon, germanium silicon, germanium, or gallium arsenide. From the viewpoint of material arrangement, the crystalline phase of the doped semiconductor layer may be amorphous, microcrystalline, nanocrystalline, single crystal, or polycrystalline. Specifically, the materials of the doped semiconductor layer included in the first doped region and the doped semiconductor layer included in the second doped region may be the same or different.

[0071] Here, if the first doped region includes a doped semiconductor layer located on the non-photosensitive surface of the semiconductor substrate, the doped semiconductor layer included in the first doped region may be formed directly on a portion of the non-photosensitive surface of the semiconductor substrate. Alternatively, the back-contact battery provided in the embodiments of this application further includes a passivation layer located between the doped semiconductor layer included in the first doped region and the semiconductor substrate. The material of this passivation layer can be determined according to the material of the doped semiconductor layer included in the first doped region and the actual application scenario, and is not specifically limited here. For example, if the doped semiconductor layer included in the first doped region is a doped polycrystalline silicon layer, the passivation layer is a tunnel passivation layer. Also, for example, if the doped semiconductor layer included in the first doped region includes a doped amorphous silicon layer and / or a doped microcrystalline silicon layer, the passivation layer is an intrinsic amorphous silicon layer.

[0072] Next, if the doped semiconductor layer included in the first doped region is located on a non-photosensitive surface of the semiconductor substrate, the first doped region may further include a sub-doped region formed by diffusion within the corresponding region of the semiconductor substrate. Here, if there is a passivation layer between the doped semiconductor layer included in the first doped region and the semiconductor substrate, the first doped region may also include a sub-doped region formed by diffusion within the corresponding region of the passivation layer.

[0073] If the doped semiconductor layer included in the second doped region is located on a non-light-receiving surface of the semiconductor substrate, the doped semiconductor layer included in the second doped region may be formed directly on a portion of the non-light-receiving surface of the semiconductor substrate. Alternatively, the back-contact battery provided in the embodiments of this application further includes a passivation layer located between the doped semiconductor layer included in the second doped region and the semiconductor substrate. The material of this passivation layer can be determined according to the material of the doped semiconductor layer included in the second doped region and the actual application scenario, and is not specifically limited here. For example, if the doped semiconductor layer included in the second doped region is a doped amorphous silicon layer and / or a doped microcrystalline silicon layer, the passivation layer may be an intrinsic amorphous silicon layer. Also, for example, if the doped semiconductor layer included in the second doped region is a doped polycrystalline silicon layer, the passivation layer is a tunnel passivation layer.

[0074] Next, if the second doped region is located in a doped semiconductor layer on a non-photosensitive surface of the semiconductor substrate, the second doped region may further include a sub-doped region formed by diffusion within a corresponding region of the semiconductor substrate. Here, if there is a passivation layer between the doped semiconductor layer included in the second doped region and the semiconductor substrate, the second doped region may also include a sub-doped region formed by diffusion within a corresponding region of the passivation layer.

[0075] Specifically, if there are passivation layers between the doped semiconductor layer in the first doped region and the semiconductor substrate, and between the doped semiconductor layer in the second doped region and the semiconductor substrate, the materials and / or thicknesses of the two passivation layers may be the same or different.

[0076] Exemplary, in the back-contact battery provided in the embodiment of this application, the semiconductor substrate is a P-type semiconductor substrate, and both the first doped region and the second doped region include a doped semiconductor layer formed on the non-light-receiving surface of the semiconductor substrate. Both the doped semiconductor layer included in the first doped region and the doped semiconductor layer included in the second doped region are doped polycrystalline silicon layers, and a tunnel passivation layer is formed between each of the doped semiconductor layers included in the first doped region and the doped semiconductor layer included in the second doped region and the semiconductor substrate.

[0077] From a morphological standpoint, the embodiments of this application do not specifically limit the shapes of the first doped region and the second doped region, as long as it is ensured that the first doped region and the second doped region are alternately distributed with a gap between them on the non-light-receiving surface side.

[0078] For example, the first doped region and the second doped region may be distributed alternately at intervals to form a striped pattern. In this case, the striped doped regions included in the first doped region and the striped doped regions included in the second doped region are distributed parallel to each other at intervals. The conductive semiconductor structure may also be such that at least a portion of it is of the opposite conductivity type and is located between two adjacent striped doped regions.

[0079] Alternatively, as shown in Figure 2, the first doped region 11 and the second doped region 12 may be distributed alternately at intervals in a comb-like pattern. In this case, both the first doped region 11 and the second doped region 12 include a plurality of stripe-shaped doped regions 14 and at least one connection region 15. The stripe-shaped doped regions 14 included in the first doped region 11 and the stripe-shaped doped regions 14 included in the second doped region 12 are distributed alternately in parallel and at intervals, and each connection region 15 is electrically connected to a corresponding stripe-shaped doped region 14 of the same conductivity type as itself, and the direction of extension of the connection region 15 is different from the direction of extension of the stripe-shaped doped regions 14.

[0080] Regarding the conductive semiconductor structure, the embodiments of this application do not specifically limit the form of the conductive semiconductor structure. For example, the orthographic projection on the non-light-receiving side of each conductive semiconductor structure may be rectangular, trapezoidal, hexagonal, or bead-shaped. Furthermore, the embodiments of this application do not specifically limit the conductivity type and impurity doping concentration of the conductive semiconductor structure, as long as the first doped region and the second doped region can be electrically connected.

[0081] From an actual manufacturing standpoint, the conductive semiconductor structure may be fabricated separately from the first and second doped regions so as to be formed on the non-light-receiving side of the semiconductor substrate; in other words, the conductive semiconductor structure is not integrally continuous with either the first or second doped region. In this case, the material of the conductive semiconductor structure may be the same as or different from the material of the first or second doped region. The impurity doping concentration in the conductive semiconductor structure may be greater than, equal to, or less than the impurity doping concentration in either the first or second doped region. Furthermore, in this case, if the conductive semiconductor structure is formed on a semiconductor substrate, at least a portion of the conductive semiconductor structure may be directly located on the semiconductor substrate, or a passivation layer may be formed between it and the semiconductor substrate. The material of this passivation layer can be determined according to the material of the conductive semiconductor structure. For example, if the conductive semiconductor structure is a doped amorphous silicon layer and / or a doped microcrystalline silicon layer, the passivation layer may be an intrinsic amorphous silicon layer. Furthermore, for example, if the conductive semiconductor structure is a doped polycrystalline silicon layer, the passivation layer is a tunnel passivation layer. Specifically, if there are passivation layers between the first doped region and / or the second doped region and the semiconductor substrate, and between the conductive semiconductor structure and the semiconductor substrate, the material and / or thickness of at least two of the passivation layers may be the same or different.

[0082] As shown in Figure 5, the conductive semiconductor structure 13 may have the same conductivity type as the first doped region 11 and be integrally continuous with the first doped region 11. In this case, the material and impurity dope concentrations of the conductive semiconductor structure 13 are the same as those of the first doped region 11 (Figure 5 is a schematic longitudinal cross-sectional view in the A-A' direction of Figure 3). Alternatively, as shown in Figure 6, the conductive semiconductor structure 13 may have the same conductivity type as the second doped region 12 and be integrally continuous with the second doped region 12. In this case, the material and impurity dope concentrations of the conductive semiconductor structure 13 are the same as those of the second doped region 12.

[0083] If the conductive semiconductor structure includes a doped semiconductor layer located on the non-photosensitive surface of the semiconductor substrate, the region corresponding to the conductive semiconductor structure may include the region where the doped semiconductor layer is located, and may further include a sub-doped region formed by diffusion within the corresponding region of the semiconductor substrate. Here, if there is a passivation layer between the doped semiconductor layer included in the conductive semiconductor structure and the semiconductor substrate, the region corresponding to the conductive semiconductor structure may also include a sub-doped region formed by diffusion within the corresponding region of the passivation layer.

[0084] It is important to note that in actual manufacturing processes, the conductive semiconductor structure can be manufactured simultaneously with the first or second doped region using the same process. For example, if the first or second doped region and the conductive semiconductor structure are integrally continuous, the first or second doped region, located only on a localized area of ​​the non-light-receiving surface, can be obtained by selectively etching the doped semiconductor material layer integrally formed on the non-light-receiving surface. Based on this, if the conductive semiconductor structure and the first doped region (or second doped region) are integrally continuous, the conductive semiconductor structure and the first doped region (or second doped region) can be manufactured based on the same doped semiconductor material layer. This reduces the manufacturing cost of back-contact batteries, eliminates the need to separately form the conductive semiconductor structure through deposition and etching processes, simplifies the back-contact battery manufacturing flow, and improves the manufacturing efficiency of back-contact batteries. When the conductive semiconductor structure is not integrally continuous with either the first doped region or the second doped region, it is possible to form a conductive semiconductor structure that satisfies the requirements of the corresponding material and dope concentration according to the needs of the actual application, without the need to make the material and dope concentration of the conductive semiconductor structure the same as the integrally continuous first doped region or second doped region, as is the case when the conductive semiconductor structure is integrally continuous with either the first or second doped region, thereby improving the applicability of the back contact battery provided in the embodiments of this application to different application scenarios.

[0085] From the standpoint of setting relative heights, the non-light-receiving surface of the semiconductor substrate may be planar, in which case the surfaces corresponding to the non-light-receiving side of the first doped region, the second doped region, and the conductive semiconductor structure are flush.

[0086] Alternatively, there is a height difference greater than zero between the surfaces corresponding to the non-photosensitive sides of the semiconductor substrates in the first doped region and the second doped region. In this case, the smaller of the two surfaces corresponding to the non-photosensitive sides of the semiconductor substrate in the first doped region and the non-photosensitive side of the semiconductor substrate in the second doped region may be at the same height as the surface corresponding to the non-photosensitive side of the conductive semiconductor structure. The larger of the two surfaces corresponding to the non-photosensitive sides of the semiconductor substrate in the first doped region and the non-photosensitive side of the semiconductor substrate in the second doped region may be at the same height as the surface corresponding to the non-photosensitive side of the conductive semiconductor structure. The height of the surface corresponding to the non-photosensitive side of the conductive semiconductor structure may be between the height of the surface corresponding to the non-photosensitive side of the semiconductor substrate in the first doped region and the height of the surface corresponding to the non-photosensitive side of the semiconductor substrate in the second doped region.

[0087] Furthermore, the specific formation location of the portion located between the first doped region and the second doped region of each conductive semiconductor structure can be determined according to the morphology of the first and second doped regions and the actual application scenario, as long as the first doped region and the second doped region can be electrically connected via the conductive semiconductor structure.

[0088] For example, if the first doped region and the second doped region are distributed alternately at intervals so as to form stripes, at least a portion of at least one conductive semiconductor structure is located between two adjacent striped doped regions of opposite conductivity types.

[0089] For example, when the first doped region and the second doped region are distributed alternately at intervals in a comb-like pattern, as shown in Figures 2 and 3, at least one conductive semiconductor structure 13 may be located between two adjacent striped doped regions 14, each belonging at least part to the first doped region 11 and the second doped region 12, respectively. In this case, the width direction of the conductive semiconductor structure 13 is parallel to the direction of extension of the striped doped region 14. And / or, as shown in Figures 2 and 4, at least one conductive semiconductor structure 13 may be located between one striped doped region 14, each belonging at least part to one of the first doped region 11 and the second doped region 12, and an adjacent connecting region 15, each belonging to the other of the first doped region 11 and the second doped region 12. In this case, the width direction of the conductive semiconductor structure 13 is parallel to the distribution direction of the striped doped region 14 of the opposite conductivity type. In this case, there are at least three selectable configurations for the arrangement position of each conductive semiconductor structure 13 on the non-light-receiving surface side, which makes it easier to select an appropriate configuration according to the requirements of different application scenarios and improves the applicability of the back contact battery provided in the embodiment of this application to different application scenarios.

[0090] Specifically, as shown in Figures 3 to 6, the conductive semiconductor structure 13 may be located only between the first doped region 11 and the second doped region 12.

[0091] Alternatively, as shown in Figures 7 to 9, the conductive semiconductor structure 13 may include an electrically contacting first conductive semiconductor portion 17 and a second conductive semiconductor portion 18. The first conductive semiconductor portion is located in the space region, and the second conductive semiconductor portion 18 is positioned above the portion of the first doped region and / or the second doped region opposite to the semiconductor substrate.

[0092] Here, from the viewpoint of placement, as shown in Figure 7, the second conductive semiconductor portion 18 may be placed only on the first doped region. As shown in Figure 8, the second conductive semiconductor portion 18 may be placed only on the second doped region. As shown in Figure 9, the second conductive semiconductor portion 18 may be placed on both the first doped region and the second doped region. In this case, there are multiple selectable configurations for the formation range of the conductive semiconductor structure 13, thereby preventing the requirements for etching accuracy from becoming too strict in order to obtain a conductive semiconductor structure 13 located only between the first doped region and the second doped region, and reducing the difficulty of etching. At the same time, it is also possible to ensure that the first doped region is electrically connected locally through the conductive semiconductor structure 13.

[0093] From the viewpoint of arrangement direction, if the first doped region and the second doped region are distributed alternately with spacing between them so as to form a stripe shape, the second conductive semiconductor portion may be positioned above the portion of the corresponding striped doped region that is opposite to the semiconductor substrate in the width direction of the striped doped region. In this case, the arrangement width of the portion of the second conductive semiconductor portion that is positioned on the corresponding striped doped region in the width direction of the striped doped region is defined as X1.

[0094] Alternatively, as shown in Figure 2, if the first doped region 11 and the second doped region 12 are alternately distributed in a comb-like pattern, the second conductive semiconductor portion 18 may be arranged on the striped doped region 14 included in the first doped region and / or the striped doped region 14 included in the second doped region in the width direction of the striped doped region 14, as shown in Figures 7 to 9. In this case, the arrangement width of the portion of the second conductive semiconductor portion 18 arranged on the corresponding striped doped region 14 in the width direction of the striped doped region 14 is defined as X1. Alternatively, as shown in Figure 10, the second conductive semiconductor portion 18 may be arranged on the striped doped region 14 included in the first doped region and / or the striped doped region 14 included in the second doped region in the extending direction of the striped doped region 14, as shown in Figure 7 to 9. Alternatively, as shown in Figure 10, the second conductive semiconductor portion 18 may be arranged on the connection region 15 included in the first doped region and / or the connection region 15 included in the second doped region in the extending direction of the stripe-shaped doped region 14. In this case, the arrangement width of the portion of the second conductive semiconductor portion that is arranged on the corresponding connection region 15 in the extending direction of the stripe-shaped doped region 14 is defined as X3.

[0095] From the viewpoint of arrangement distribution, if the conductive semiconductor structure includes a first conductive semiconductor portion and a second conductive semiconductor portion, the second conductive semiconductor portion 18 may be arranged above one side in the width direction of the first doped region and / or the second doped region, as shown in Figures 7 to 9. Alternatively, as shown in Figure 11, the second conductive semiconductor portion 18 may be arranged above both sides in the width direction of the first doped region 11 and / or the second doped region 12.

[0096] From the viewpoint of arrangement, as shown in Figures 12 to 13, the second conductive semiconductor portion 18 may be in direct contact with the first doped region 11 and / or the second doped region 12. In this case, not only are the side walls of the conductive semiconductor structure 13 electrically in contact with the first doped region 11 and the second doped region 12, respectively, but the portion of the conductive semiconductor structure 13 placed on the first doped region 11 and / or the portion placed on the second doped region 12 are also electrically in contact with the first doped region 11 and / or the second doped region 12.

[0097] Alternatively, in the actual manufacturing process, as shown in Figure 14, corresponding physical space layers 16 may be formed on the first doped region 11 and the second doped region 12, respectively. These physical space layers 16 may be formed when the first doped region 11 and the second doped region 12 are manufactured by a diffusion process, and may be formed in such a way that the formed first doped region 11 and the second doped region 12 are not affected by subsequent processes (for example, when manufacturing the second doped region 12 on the non-photosensitive side after the formation of the first doped region 11, the physical space layer 16 may be formed on the surface of the first doped region 11 so that the formed first doped region 11 does not invert). Based on this, the physical space layer 16 may be a conductive layer, in which case the corresponding portion of the conductive semiconductor structure 13 is in electrical contact with the first doped region 11 and / or the second doped region 12, and the corresponding electrical contact situation of the conductive semiconductor structure 13 can refer to the corresponding electrical contact situation in the case of direct contact described above. Alternatively, the physical space layer 16 may be a non-conductive insulating layer, in which case, regardless of whether the conductive semiconductor structure 13 is positioned on at least one of the first doped region 11 and the second doped region 12, the conductive semiconductor structure 13 is electrically in contact only with the sides of the first doped region 11 and the second doped region 12, respectively, that is, the electrical contact situation when the conductive semiconductor structure 13 is located only between the first doped region 11 and the second doped region 12 can be referenced.

[0098] From the viewpoint of arrangement structure, the contact surface between the conductive semiconductor structure and the first doped region and the second doped region, which has a conductivity type opposite to that of the conductive semiconductor structure, includes a lateral effective electrical contact surface. This lateral effective electrical contact surface may be parallel to the thickness direction of the semiconductor substrate, or it may have a certain angle with respect to the thickness direction of the semiconductor substrate. The embodiments of this application do not specifically limit the magnitude of this angle.

[0099] The specific structure of the conductive semiconductor structure can be determined according to the formation positions of the first doped region and the second doped region on the non-photosensitive side of the semiconductor substrate. Specifically, this can be explained by dividing it into the following four cases.

[0100] Case 1: As shown in Figure 67, if one of the first doped region 11 and the second doped region 12 includes a doped semiconductor layer located on the non-light-receiving surface of the semiconductor substrate, and the other of the first doped region 11 and the second doped region 12 is located within the semiconductor substrate, the conductive semiconductor structure 13 may include a first conductive semiconductor portion 17 and a second conductive semiconductor portion 18. The second conductive semiconductor portion 18 is positioned above the portion of the first doped region 11 and the second doped region 12 that is located within the semiconductor substrate, on the side opposite to the semiconductor substrate.

[0101] Case 2: As shown in Figure 68, the conductive semiconductor structure 13 further includes a doped semiconductor layer in which one of the first doped region 11 and the second doped region 12 is located on the non-light-receiving surface of the semiconductor substrate, and the other of the first doped region 11 and the second doped region 12 is located within the semiconductor substrate. The conductive semiconductor structure 13 further includes a third conductive semiconductor portion 21 that is in electrical contact with the first conductive semiconductor portion 17. The third conductive semiconductor portion 21 is positioned above the portion of the doped semiconductor layer opposite to the semiconductor substrate.

[0102] Case 3: As shown in Figure 63, when both the first doped region 11 and the second doped region 12 include a doped semiconductor layer located on the non-light-receiving surface of the semiconductor substrate, the conductive semiconductor structure includes the first conductive semiconductor portion and the second conductive semiconductor portion.

[0103] Case 4: As shown in Figure 65, when both the first doped region 11 and the second doped region 12 are formed within a semiconductor substrate, the conductive semiconductor structure 13 further includes a third conductive semiconductor portion 21 that electrically contacts the first conductive semiconductor portion 17. The second conductive semiconductor portion 18 is positioned above the portion of one of the first doped region 11 and the second doped region 12 that is opposite to the semiconductor substrate, and the third conductive semiconductor portion 21 is positioned above the portion of the other of the first doped region 11 and the second doped region 12 that is opposite to the semiconductor substrate.

[0104] From the perspective of surface height differences, the ratio of the height from the upper surface of the second conductive semiconductor portion to the upper surface of the first doped region or second doped region located directly below it, in the thickness direction of the semiconductor substrate, to the thickness of the first doped region or second doped region located directly below the same second conductive semiconductor portion, may be 0.5 or more and 1.5 or less. In this case, it is possible to prevent the thickness of the first doped region or second doped region from becoming smaller due to a large ratio, thereby preventing a deterioration in their corresponding field passivation capability. Conversely, it is also possible to prevent the thickness of the first doped region or second doped region from becoming larger due to a small ratio, thereby preventing a corresponding increase in parasitic absorption and ensuring that the back contact battery has high operating efficiency.

[0105] For example, in the thickness direction of the semiconductor substrate, the height from the top surface of the second conductive semiconductor portion to the top surface of the first doped region or the second doped region located directly below it may be 50 nm or more and 2 μm or less. For instance, in the thickness direction of the semiconductor substrate, the height from the top surface of the second conductive semiconductor portion to the top surface of the first doped region or the second doped region located directly below it may be 50 nm, 100 nm, 300 nm, 600 nm, 900 nm, 1.2 μm, 1.5 μm, or 2 μm, etc.

[0106] Furthermore, if the first doped region, the second doped region, and the conductive semiconductor structure all include a doped semiconductor layer, as shown in Figures 18, 19, 24, and 34, the surface height of the region corresponding to the non-light-receiving conductive semiconductor structure 13 may be greater than or equal to the surface height of the region corresponding to the first doped region 11 (or second doped region 12) which has the opposite conductivity type to the non-light-receiving conductive semiconductor structure 13. Alternatively, as shown in Figures 20, 25, and 36, the surface height of the region corresponding to the non-light-receiving conductive semiconductor structure 13 may be less than the surface height of the region corresponding to the first doped region 11 (or second doped region 12) which has the opposite conductivity type to the non-light-receiving conductive semiconductor structure 13. In this case, during the actual manufacturing process, when forming the conductive semiconductor structure 13, the manufacturing material for the doped semiconductor layer included in the conductive semiconductor structure 13 is less likely to fill the corners due to height differences, and as a result, it tends to be difficult for the doped semiconductor layer included in the conductive semiconductor structure 13 to make complete contact with each part of the surface of the corresponding structure at the corners. Therefore, compared to the case where the surface height of the region corresponding to the non-light-receiving conductive semiconductor structure 13 may be smaller than the surface height of the region corresponding to the first doped region 11 (or second doped region 12) which has the opposite conductivity type to the non-light-receiving conductive semiconductor structure 13, if the surface height of the region corresponding to the non-light-receiving conductive semiconductor structure 13 may be greater than or equal to the surface height of the region corresponding to the first doped region 11 (or second doped region 12) which has the opposite conductivity type to the non-light-receiving conductive semiconductor structure 13, the portion filled in the corners of the doped semiconductor layer included in the conductive semiconductor structure 13 can be shifted from the sidewall of the doped semiconductor layer included in the first doped region 11 (or doped semiconductor layer included in the second doped region 12) which has the opposite conductivity type to itself, thereby ensuring that there is a large effective electrical contact area on the side between the conductive semiconductor structure 13 and the first doped region 11 (or second doped region 12) which has the opposite conductivity type to itself.

[0107] Specifically, if the placement height of a doped semiconductor layer included in a conductive semiconductor structure on the non-photosensitive side is smaller than the placement height of a doped semiconductor layer (or a doped semiconductor layer included in a second doped region) included in a first doped region with the opposite conductivity type to the conductive semiconductor structure on the non-photosensitive side, the magnitude of this height difference can be determined according to the manufacturing process of the conductive semiconductor structure in the actual application. For example, the difference between the surface height of the region corresponding to the doped semiconductor layer included in the conductive semiconductor structure on the non-photosensitive side and the surface height of the region corresponding to the doped semiconductor layer included in one of the first and second doped regions on the non-photosensitive side that has the opposite conductivity type to the conductive semiconductor structure may be -2 μm or more and -0.4 μm or less. For example, this height difference may be -2 μm, -1.8 μm, -1.5 μm, -1.2 μm, -1 μm, -0.8 μm, or -0.4 μm, etc.

[0108] The type of physical space layer formed on the first and second doped regions can be determined according to the conductive properties of the physical space layer and the actual application scenario. For example, the physical space layer may include a transparent conductive layer to improve carrier transmission efficiency. Alternatively, the physical space layer may include a surface passivation layer of a material such as silicon nitride, aluminum oxide, or titanium oxide to passivate surface defects on the side of the first and second doped regions away from the semiconductor substrate. Alternatively, the physical space layer may include a doped silicon glass layer (this doped silicon glass layer may be a phosphate glass layer or a borosilicate glass layer, etc.) formed when doping the first and / or second doped regions of the silicon material by a diffusion process. The doped silicon glass layer may be a conductive layer or an insulating layer. Specifically, the doped silicon glass layer may be an insulating layer when its thickness is large, and a conductive layer with a constant electrical conductivity when its thickness is small. In this application, a doped silicon glass layer having a certain electrical conductivity is referred to as a conductive doped silicon glass layer, and in this application, "doped silicon glass layer" refers to an insulating doped silicon glass layer unless otherwise specified.

[0109] In practical applications, the height of the lateral effective electrical contact surface is defined as the lateral effective electrical contact height Z. The following explanation will be divided into at least two cases based on the formation positions of the first and second doped regions on the non-light-receiving surface side.

[0110] Case 1: As shown in Figures 64 and 66, the first doped region 11, the second doped region 12, and at least a portion of the conductive semiconductor structure 13 are all formed within a semiconductor substrate, and the surfaces of the first doped region 11, the second doped region 12, and the conductive semiconductor structure 13 that are opposite to the light-receiving surface of the semiconductor substrate are all flush with the surface of the corresponding non-light-receiving region of the semiconductor substrate. In this case, the contact surface between the conductive semiconductor structure 13 and the one of the first doped region 11 and the second doped region 12 that has the opposite conductivity type to the conductive semiconductor structure includes a side effective electrical contact surface, the height of which is the side effective electrical contact height Z, and the side effective electrical contact height Z is equal to the minimum of the first depth and the second depth, the first depth being the depth of the one of the first doped region 11 and the second doped region 12 that has the opposite conductivity type to the conductive semiconductor structure 13, and the second depth being the depth of the portion of the conductive semiconductor structure 13 within the semiconductor substrate. For example, if, among the first doped region 11 and the second doped region 12, the depth of one of the regions with the opposite conductivity type to the conductive semiconductor structure 13 is the depth H1 of the first doped region 11, and the depth H of the conductive semiconductor structure 13 is greater than H1, then the effective electrical contact height Z of the side surface is equal to H1.

[0111] Case 2: Of the first doped region and the second doped region, the one with the opposite conductivity type to the conductive semiconductor structure, and the conductive semiconductor structure both include a doped semiconductor layer formed on the non-light-receiving surface of the semiconductor substrate. The contact surface between the one of the first and second doped regions with the opposite conductivity type to the conductive semiconductor structure and the conductive semiconductor structure includes a side effective electrical contact surface, and the height of this side effective electrical contact surface is denoted as the side effective electrical contact height Z. This side effective electrical contact height Z is equal to the minimum value of the first and second thicknesses. In the direction of extension of the side effective electrical contact surface, the first thickness is the thickness corresponding to the side effective electrical contact surface of the one of the first and second doped regions with the opposite conductivity type to the conductive semiconductor structure, and the second thickness is the thickness corresponding to the side effective electrical contact surface of the conductive semiconductor structure. For example, in the extending direction of the side effective electrical contact surface, if the thickness of the side effective electrical contact surface corresponding to one of the first and second doped regions, which has a conductivity type opposite to that of the conductive semiconductor structure, is H2, and the thickness H of the conductive semiconductor structure is greater than H2, then the side effective electrical contact height Z is equal to H2.

[0112] Specifically, in Case 2, where the first doped region, the second doped region, and the conductive semiconductor structure all include a doped semiconductor layer formed on a non-light-receiving surface, the relationship between the conductivity type of the conductive semiconductor structure and each of the first and second doped regions, the placement height of the doped semiconductor layer included in the first and second doped regions on the semiconductor substrate, and the formation status of the conductive semiconductor structure are considered, and the lateral effective electrical contact height Z and the corresponding effective electrical contact area of ​​the conductive semiconductor structure are described.

[0113] Case 1: The conductive semiconductor structure is integrally continuous with the first doped region, and in this case, the conductive semiconductor structure has the opposite conductivity type to the second doped region. In this case, if the conductive semiconductor structure is located only between the first doped region and the second doped region, as shown in Figure 15, if the semiconductor substrate is planar, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H2 × W, and the side effective electrical contact height Z is H2, where H2 is the thickness of the second doped region. As shown in Figure 16, if the placement height of the doped semiconductor layer included in the first doped region and the conductive semiconductor structure on the semiconductor substrate is greater than the placement height of the second doped region, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H × W, and the side effective electrical contact height Z is H, where H is the thickness of the conductive semiconductor structure. As shown in Figure 17, if the placement height of the doped semiconductor layer in the first doped region and the conductive semiconductor structure on the semiconductor substrate is smaller than the placement height of the doped semiconductor layer in the second doped region, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H2 × W, and the lateral effective electrical contact height Z is H2.

[0114] In Case 1, when the conductive semiconductor structure includes a first conductive semiconductor portion and a second conductive semiconductor portion, as shown in Figures 18 to 20, regardless of whether the placement heights of the doped semiconductor layers included in the first doped region and the second doped region are the same on the semiconductor substrate, if the corresponding placement method of the second conductive semiconductor portion 18 is electrical contact, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H2 × W + W × X, and the side effective electrical contact height Z is H2. If the corresponding placement method of the second conductive semiconductor portion 18 is insulating, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H2 × W, and the side effective electrical contact height Z is H2. However, X is one of X1, X2, or X3.

[0115] Case 2: The conductive semiconductor structure is integrally continuous with the second doped region, and in this case, the conductive semiconductor structure has the opposite conductivity type to the first doped region. In this case, if the conductive semiconductor structure is located only between the first doped region and the second doped region, as shown in Figure 21, if the semiconductor substrate is planar, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H1 × W, and the side effective electrical contact height Z is H1, where H1 is the thickness of the first doped region. As shown in Figure 22, if the placement height of the doped semiconductor layer included in the second doped region and the conductive semiconductor structure on the semiconductor substrate is smaller than the placement height of the doped semiconductor layer included in the first doped region, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H1 × W, and the side effective electrical contact height Z is H1. As shown in Figure 23, if the placement height of the doped semiconductor layer included in the second doped region and the conductive semiconductor structure on the semiconductor substrate is larger than the placement height of the doped semiconductor layer included in the first doped region, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H × W, and the side effective electrical contact height Z is H.

[0116] In Case 2, when the conductive semiconductor structure includes a first conductive semiconductor portion and a second conductive semiconductor portion, as shown in Figures 24 to 26, regardless of whether the placement heights of the doped semiconductor layers included in the first doped region and the second doped region are the same on the semiconductor substrate, if the corresponding arrangement method of the second conductive semiconductor portion 18 is electrical contact, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H1 × W + W × X and the side effective electrical contact height Z is H1. If the corresponding arrangement method of the second conductive semiconductor portion 18 is insulating, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H1 × W and the side effective electrical contact height Z is H1.

[0117] Case 3: The conductive semiconductor structure is not integrally continuous with either the first doped region or the second doped region, and the conductive semiconductor structure has a conductivity type opposite to that of the first doped region. In this case, as shown in Figure 33, if the placement height on the semiconductor substrate of both the second doped region and the doped semiconductor layer included in the conductive semiconductor structure is greater than the placement height of the doped semiconductor layer included in the first doped region, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H × W, and the side effective electrical contact height Z is H. As shown in Figures 27 to 32 and Figures 34 to 39, in the case of other distributions, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H1 × W, and the side effective electrical contact height Z is H1.

[0118] Case 4: The conductive semiconductor structure is not integrally continuous with either the first doped region or the second doped region, and the conductive semiconductor structure has a conductivity type opposite to that of the second doped region. In this case, as shown in Figures 43 and 44, if the placement height on the semiconductor substrate of both the first doped region and the doped semiconductor layer included in the conductive semiconductor structure is greater than the placement height of the doped semiconductor layer included in the second doped region, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H × W, and the side effective electrical contact height Z is H. As shown in Figures 40 to 42 and Figures 45 to 49, in the case of other distributions, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is H² × W, and the side effective electrical contact height Z is H².

[0119] It should be noted that, as can be seen from Cases 1 to 4 above, the effective electrical contact height on the side when the first doped region and the second doped region are electrically coupled via the conductive semiconductor structure is Z. Here, as shown in Figures 15, 18, 21, 27 to 29, 34 and 35, and 40 and 42, when the non-light-receiving surface of the semiconductor substrate is planar, the effective electrical contact height on the side is equal to the thickness of one of the first doped region 11 and the second doped region 12 that has a conductivity type opposite to that of the conductive semiconductor structure 13 (i.e., H1 or H2).

[0120] Alternatively, as shown in Figures 16, 23, 33, 43, and 44, if the arrangement height of the doped semiconductor layer included in the first doped region 11 and the second doped region 12 on the non-light-receiving side of the semiconductor substrate, where the conductivity type is opposite to that of the conductive semiconductor structure 13, is smaller than the arrangement height of the doped semiconductor layer included in the conductive semiconductor structure 13 on the non-light-receiving side of the semiconductor substrate, and a portion of the side surface of the doped semiconductor layer included in the first doped region 11 and the second doped region 12, where the conductivity type is opposite to that of the conductive semiconductor structure 13, is in electrical contact with the semiconductor substrate, and a portion of the side surface of the doped semiconductor layer included in the first doped region 11 and the second doped region 12, where the conductivity type is opposite to that of the conductive semiconductor structure 13, is in electrical contact with the conductive semiconductor structure 13, then the effective electrical contact height Z of the side surface is equal to the thickness (i.e., H) of the conductive semiconductor structure 13.

[0121] Alternatively, as shown in Figures 17, 19, 20, 22, 24-26, 30-32, and 37-39, if the arrangement heights of the doped semiconductor layers included in the first doped region 11 and the second doped region 12 on the non-light-receiving side of the semiconductor substrate are different, and each region of the doped semiconductor layer on the side surface corresponding to the conductive semiconductor structure is in electrical contact with the conductive semiconductor structure, then the effective electrical contact height Z on the side surface is equal to the thickness of the one of the first doped region 11 and the second doped region 12 that has a conductivity type opposite to that of the conductive semiconductor structure 13.

[0122] Furthermore, as can be seen from the above, if, among the first and second doped regions on the side of the semiconductor substrate closer to the light-receiving surface, the arrangement height of the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure is smaller than the arrangement height of the doped semiconductor layer included in the other of the first and second doped regions on the side of the semiconductor substrate closer to the light-receiving surface, and a part of the side surface of the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure is electrically in contact with the semiconductor substrate, and the other part of the side surface of the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure is electrically in contact with the conductive semiconductor structure, then a part of the side surface of the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure is electrically in contact with the semiconductor substrate, and as a result, only a part of the side surface of the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure is electrically in contact with the conductive semiconductor structure. In this case, the range of the difference between the surface height of the region corresponding to the conductive semiconductor structure on the non-light-receiving surface and the surface height of the region corresponding to the one of the first and second doped regions of the non-light-receiving surface whose conductivity type is opposite to that of the conductive semiconductor structure can be determined according to the manufacturing process of the first and second doped regions in the actual application. For example, in this case, in the thickness direction of the semiconductor substrate, the difference between the surface height of the region on the non-light-receiving surface corresponding to the conductive semiconductor structure and the surface height of the region corresponding to the doped semiconductor layer included in the one of the first and second doped regions whose conductivity type is opposite to that of the conductive semiconductor structure may be 0.4 μm or more and 2 μm or less. For example, in this case, the difference between the surface height of the region corresponding to the conductive semiconductor structure on the non-light-receiving surface and the surface height of the region corresponding to the one of the first and second doped regions of the non-light-receiving surface whose conductivity type is opposite to that of the conductive semiconductor structure may be 0.4 μm, 0.6 μm, 0.8 μm, 1 μm, 1.5 μm, 1.8 μm, or 2 μm, etc.In this case, we will explain using the example of the case where the conductivity type of the first doped region and the conductive semiconductor structure are opposite. When forming the doped semiconductor layer included in the first doped region, the manufacturing material for the doped semiconductor layer included in the first doped region is less likely to fill the corners due to height differences. As a result, it becomes difficult for the doped semiconductor layer included in the first doped region to make complete contact with each part of the surface of the semiconductor substrate (or the semiconductor substrate and the conductive semiconductor structure) at the corners. Therefore, by keeping the difference between the surface height of the region corresponding to the conductive semiconductor structure on the non-light-receiving surface and the surface height of the region corresponding to one of the first and second doped regions on the non-light-receiving surface that has a conductivity type opposite to that of the conductive semiconductor structure within the above range, the portion of the doped semiconductor layer filled at the corners of the first doped region can be shifted away from the sidewall of the conductive semiconductor structure whose conductivity type is opposite to its own, ensuring that there is a large effective electrical contact area between the conductive semiconductor structure and the first doped region whose conductivity type is opposite to its own. When the conductivity types of the second doped region and the conductive semiconductor structure are opposite, the corresponding beneficial effects are the same as those described above and will not be explained again here.

[0123] The corresponding effective electrical contact surface of each conductive semiconductor structure includes the side effective electrical contact surface and / or the top effective electrical contact surface. Specifically, the effective electrical contact area S is equal to α × W × X + β × Z × W, where α and β are constants between 0 and 1. Here, the specific values ​​of α and β can be determined according to the formation position of the conductive semiconductor structure, the conductive performance of the physical space layer, and the specific structure of the back contact battery.

[0124] For example, if the conductive semiconductor structure does not include a second conductive semiconductor portion located above the portion of the semiconductor substrate opposite to the first doped region and / or the second doped region, or if the corresponding arrangement of the second conductive semiconductor portion included in the conductive semiconductor structure is insulating, then α is equal to 0. In this case, β is greater than 0 and less than or equal to 1, and the effective electrical contact area is equal to β × Z × W.

[0125] For example, if both the first and second doped regions are formed within the semiconductor substrate and the conductive semiconductor structure is formed only on the semiconductor substrate, or if one of the first and second doped regions, the one with the opposite conductivity type to the conductive semiconductor structure, is located within the semiconductor substrate and the conductive semiconductor structure is positioned only above the portion of the first and second doped region that has the opposite conductivity type to the conductive semiconductor structure, on the side opposite to the semiconductor substrate, then β is equal to 0. The effective electrical contact area is the top surface effective electrical contact area. Next, in this case, α is greater than 0 and less than or equal to 1. The effective electrical contact area is equal to α × W × X.

[0126] For example, if the corresponding arrangement of the second conductive semiconductor portion included in the conductive semiconductor structure is electrical contact, and the effective electrical contact surface between the first doped region and the conductive semiconductor structure (one of the first and second doped regions having opposite conductivity types) and the conductive semiconductor structure includes the lateral effective electrical contact surface, then α is greater than 0 and less than or equal to 1, and β is between 0 and 1. It can be understood that the effective electrical contact area S is equal to α × W × X + β × Z × W.

[0127] Here, if α is greater than 0, the specific value of α can be determined according to the electrical conductivity between the second conductive semiconductor portion and the top effective electrical contact surface of the first doped region and the second doped region that has a conductivity type opposite to that of the conductive semiconductor structure. For example, if the second conductive semiconductor portion is formed directly above the portion of the first doped region and the second doped region that has a conductivity type opposite to that of the conductive semiconductor structure and is opposite to that of the semiconductor substrate, α may be equal to 1. Alternatively, if a physical space layer with good conductivity, such as a transparent conductive layer, is formed between the second conductive semiconductor portion and the first doped region and the second doped region that has a conductivity type opposite to that of the conductive semiconductor structure, α may also be equal to 1. Alternatively, if a physical space layer with low conductivity, such as a conductive doped silicon glass layer, is formed between the second conductive semiconductor portion and the first doped region and the second doped region that has a conductivity type opposite to that of the conductive semiconductor structure, α may be less than 1.

[0128] If β is greater than 0, the specific value of β can be determined according to the electrical conductivity between the conductive semiconductor structure and one of the first and second doped regions, which has a conductivity type opposite to that of the conductive semiconductor structure. For example, if the conductive semiconductor structure, the first doped region, and the second doped region all contain doped semiconductor layers, and the doped semiconductor layer included in the conductive semiconductor structure is in direct contact with the side of the doped semiconductor layer included in the first and second doped regions, which has a conductivity type opposite to that of the conductive semiconductor structure, then β may be equal to 1. Also, β may be greater than or equal to α.

[0129] In the above case, the effective electrical contact area can be adjusted by adjusting the sizes of α and β, thereby obtaining an appropriate effective electrical contact surface area and achieving optimal design of the product configuration.

[0130] Next, in practical applications, the orthographic area on the non-light-receiving side of a conductive semiconductor structure affects the corresponding effective electrical contact area of ​​the conductive semiconductor structure, which in turn affects the magnitude of the leakage current in the first and second doped regions of the conductive semiconductor structure, and may affect the reverse breakdown voltage and operating efficiency of the back-contact battery under normal operating conditions. Based on this, the ratio of the orthographic area on the non-light-receiving side of each conductive semiconductor structure to the area of ​​the non-light-receiving surface, as well as the placement range of the conductive semiconductor structure on the first and / or second doped regions, can be determined according to the requirements for the reverse breakdown voltage and operating efficiency of the back-contact battery in actual application scenarios, and the actual precision of the manufacturing equipment used to produce the back-contact battery.

[0131] For example, let S1 be the area of ​​the orthographic projection on the non-photosensitive side of the portion located between the first doped region and the second doped region of at least one conductive semiconductor structure, and let S2 be the area of ​​the non-photosensitive surface. The ratio of S1 to S2 is 8.5 × 10⁻⁶. -7 % or more 6.67 × 10 -1 It may be less than %. For example, the ratio of the orthographic area on the non-photosensitive side of at least one conductive semiconductor structure to the area of ​​the non-photosensitive surface is 8.5 × 10-7 %, 1×10 -6 %, 1×10 -5 %, 1×10 -4 %, 1×10 -3 %, 1×10 -2 %, 1×10 -1 % or 6.67×10 -1 % or the like may be used. In this case, it is possible to prevent a decrease in the reduction amplitude of the reverse breakdown voltage of the back contact battery due to the arrangement of the conductive semiconductor structure caused by a small S1, prevent the back contact battery from being burned out due to local heat concentration, and effectively reduce the hot spot risk of the solar module including the back contact battery provided in the embodiment of the present application. It is also possible to prevent the requirement for etching accuracy from becoming strict in order to form a conductive semiconductor structure with a small size, and reduce the difficulty of etching. Further, it is possible to prevent the leakage current during normal operation of the back contact battery from increasing due to a large S1, and further ensure that the solar module including the back contact battery provided in the embodiment of the present application has a high photoelectric conversion efficiency in the forward voltage region.

[0132] The specific value of the area of the orthographic projection on the non-light-receiving surface side of the portion located between the first doped region and the second doped region of each conductive semiconductor structure can be determined according to the ratio and the specific size of the semiconductor substrate used in the actual application scenario. For example, when the area of the non-light-receiving surface of the semiconductor substrate is 359.0364 cm 2 the area of the orthographic projection on the non-light-receiving surface side of the portion located between the first doped region and the second doped region of at least one conductive semiconductor structure may be any value of 300 μm 2 or more and 2.4 cm 2 [[ID=二十五]]or less.

[0133] Preferably, the ratio of S1 to S2 may be 7.2×10 -6 % or more and 4.​​​​​​-4 %, 1 × 10 -3 % or 4.6 × 10 -3 It may also be a percentage, etc. The preferred range of the orthographic area on the non-light-receiving side of the portion located between the first doped region and the second doped region of the conductive semiconductor structure can be determined according to the ratio and the specific size of the semiconductor substrate used in the actual application. For example, if the area of ​​the non-light-receiving surface of the semiconductor substrate is 34944 mm² 2 In this case, the orthographic area on the non-photosensitive side of the portion located between the first doped region and the second doped region of at least one conductive semiconductor structure is 0.0025 mm². 2 1.6mm 2 The following values ​​may also be used. In this case, the ratio of S1 to S2 has a large range of selectable options, allowing for the selection of an appropriate form according to the requirements of the back-contact battery layout, leakage prevention, and reduction of hot spot risk in actual application scenarios, which is advantageous in improving the applicability of the back-contact battery provided in this application to different application scenarios. It is also possible to prevent the corresponding effective electrical contact area of ​​a single conductive semiconductor structure from being too small or too large, and this effect can be seen in the preamble and will not be repeated here.

[0134] When the conductive semiconductor structure includes a first conductive semiconductor portion and a second conductive semiconductor portion, the area ratio of the orthographic projection area S4 on the non-light-receiving surface side of the second conductive semiconductor portion to the non-light-receiving surface side can be determined according to the requirements for the reverse breakdown voltage and operating efficiency of the back contact battery in the actual application scenario, as well as the actual precision of the manufacturing equipment used to manufacture the back contact battery, and is not specifically limited here.

[0135] For example, the ratio of S4 to S2 is greater than 0, which is 4.6 × 10⁻⁶. -3 It may be less than or equal to a percent. For example, the ratio of S4 to S2 is 0.1 × 10⁻⁶. -3 %, 0.5 × 10 -3 %, 1.0 × 10 -3 %, 1.5 × 10 -3 %, 2 × 10 -3 %, 2.5 × 10-3 %, 3 × 10 -3 %, 4×10 -3 % or 4.6 × 10 -3 It may also be a percentage, etc. The preferred range of the orthographic area on the non-light-receiving side of the second conductive semiconductor portion can be determined according to the ratio and the specific size of the semiconductor substrate used in the actual application. For example, if the area of ​​the non-light-receiving surface of the semiconductor substrate is 34944 mm² 2 In this case, the orthographic area on the non-light-receiving side of the second conductive semiconductor portion is greater than 0, which is 1.6 mm². 2 Any of the following values ​​may be used. In this case, the large ratio of S4 to S2 results in a larger arrangement width of the second conductive semiconductor portion on the first doped region and / or the second doped region, which can prevent it from affecting the formation of the electrode structure. This reduces the difficulty of manufacturing the electrode structure while ensuring good contact performance between the electrode structure and the corresponding doped region, as well as good transmission performance of the electrode structure itself.

[0136] The specific size of the corresponding effective electrical contact area of ​​each conductive semiconductor structure can be determined according to the formation range of the conductive semiconductor structure, the requirements for the reverse breakdown voltage and operating efficiency of the back-contact battery in the actual application scenario, the requirements for the layout size of the back-contact battery in the actual application scenario, and the actual precision of the manufacturing equipment used to produce the back-contact battery.

[0137] Here, when the conductive semiconductor structure includes a second conductive semiconductor portion, the specific size of the effective electrical contact area will be explained by dividing it into the following two cases depending on the arrangement method of the conductive semiconductor structure.

[0138] For example, if the second conductive semiconductor portion of a conductive semiconductor structure is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, the corresponding effective electrical contact area of ​​at least one conductive semiconductor structure is 0.000025 mm². 2 The above is 0.016mm 2The following may also apply: For example, in this case, the corresponding effective electrical contact area of ​​at least one conductive semiconductor structure is 0.000025 mm². 2 , 0.0001mm 2 , 0.0012mm 2 , 0.0015mm 2 , 0.0018mm 2 , 0.002mm 2 , 0.0022mm 2 , 0.0025mm 2 , 0.005mm 2 , 0.01mm 2 or 0.016mm 2 The following may also be used. In this case, by keeping the corresponding effective electrical contact area of ​​at least one conductive semiconductor structure within the above range, it is possible to prevent the reduction in the reverse breakdown voltage of the back contact battery due to the arrangement of the conductive semiconductor structure from becoming small due to a small corresponding effective electrical contact area of ​​the conductive semiconductor structure, prevent the back contact battery from burning out due to localized heat concentration, and effectively reduce the risk of hot spots in the solar module including the back contact battery provided in the embodiment of this application. It is also possible to prevent the requirements for etching accuracy from becoming too strict in order to form a small-sized conductive semiconductor structure and reduce the difficulty of etching. Furthermore, it is possible to prevent the leakage current of the back contact battery during normal operation from becoming large due to a large corresponding effective electrical contact area of ​​the conductive semiconductor structure and further ensure that the solar module including the back contact battery provided in the embodiment of this application has high photoelectric conversion efficiency in the forward voltage region. It is also possible to prevent the applicable size range of the back contact battery provided in the embodiment of this application from being limited due to increasing the values ​​of W and / or Z in order to increase the corresponding effective electrical contact area of ​​the conductive semiconductor structure and further expand the applicable range of the back contact battery provided in the embodiment of this application.

[0139] For example, if the corresponding arrangement of conductive semiconductor structures is electrical contact, the corresponding effective electrical contact area of ​​at least one conductive semiconductor structure is 0.000175 mm². 2The above is 1.616mm. 2 The following may also apply: For example, in this case, the corresponding effective electrical contact area of ​​at least one conductive semiconductor structure is 0.000175 mm². 2 , 0.001mm 2 , 0.005mm 2 , 0.01mm 2 , 0.02mm 2 , 0.04mm 2 , 0.06mm 2 , 0.08mm 2 , 0.1mm 2 , 0.2mm 2 , 0.6mm 2 , 1mm 2 , 1.2mm 2 or 1.616 mm 2 The following may also be the case. The beneficial effect in this case is that when the second conductive semiconductor portion of the conductive semiconductor structure is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, the corresponding effective electrical contact area of ​​at least one conductive semiconductor structure is 0.000025 mm². 2 The above is 0.016mm 2 The beneficial effects of the following are similar and will not be explained again here.

[0140] When the conductive semiconductor structure is located only between the first doped region and the second doped region, only the sidewalls of the conductive semiconductor structure are in contact with the first doped region and the second doped region, respectively. In this case, the corresponding effective electrical contact area of ​​the conductive semiconductor structure can refer to the corresponding effective electrical contact area when the second conductive semiconductor portion of the conductive semiconductor structure described above is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, which will not be explained again here.

[0141] The specific size of each conductive semiconductor structure can be determined according to the specific formation location of the portion located between the first and second doped regions of each conductive semiconductor structure, the placement range on the first and / or second doped regions of the conductive semiconductor structure, and the actual application scenario, provided that 0.5 × D1 ≤ W ≤ 6 × D1 is satisfied. Specifically, W may be any value between 0.5 × D1 and 6 × D1. For example, the value of W may be equal to 0.5 × D1, D1, 2 × D1, 3 × D1, 4 × D1, 5 × D1, or 6 × D1, etc.

[0142] Preferably, W may be any value between 0.5 × D1 and 3 × D1. For example, the value of W may be equal to 0.5 × D1, 0.8 × D1, D1, 1.5 × D1, 2 × D1, 2.5 × D1, or 3 × D1, etc. In this case, in practice, the width in the extending direction of the space region of the conductive semiconductor structure affects not only the effective electrical contact area between the conductive semiconductor structure and each of the first doped region and the second doped region, but the thickness of the conductive semiconductor structure (and, if the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the conductive semiconductor structure opposite to the semiconductor substrate in the first doped region and / or the second doped region, the width of the portion of the conductive semiconductor structure located on the first doped region and / or the portion located on the second doped region, or the doping concentration of impurities in the conductive semiconductor structure, etc.) may affect the size of the effective electrical contact area. For example, if the placement heights of the doped semiconductor layers included in the first doped region and the second doped region are different on the semiconductor substrate, and one of the two with the smaller placement height is smaller than the placement height of the doped semiconductor layer included in the conductive semiconductor structure on the semiconductor substrate, and the one of the two with the smaller placement height has a conductivity type opposite to that of the conductive semiconductor structure, then the larger the thickness of the doped semiconductor layer included in the conductive semiconductor structure, the larger the effective electrical contact area. In this case, by keeping the width W in the extending direction of the space region of the conductive semiconductor structure within the above range, a predetermined placement space can be secured for at least the thickness range of the conductive semiconductor structure and / or the placement width range in the case of electrical contact, thereby preventing the reduction of leakage loss of the back contact battery from becoming large due to the large thickness, width W of the conductive semiconductor structure and the placement width in the case of electrical contact, and ensuring that the back contact battery has relatively high operating efficiency.

[0143] The width of the conductive semiconductor structure can be determined according to the orthographic area on the non-light-receiving side of the conductive semiconductor structure, and the arrangement range on the first doped region and / or second doped region of the conductive semiconductor structure.

[0144] For example, as shown in Figure 3, when at least a portion of the conductive semiconductor structure 13 belongs to a first doped region and a second doped region, respectively, and is located between two adjacent striped doped regions 14, the width of the striped doped region 14 in contact with the conductive semiconductor structure 13 in the first doped region is defined as D2, the width of the striped doped region 14 in contact with the conductive semiconductor structure 13 in the second doped region is defined as D3, and the length of the conductive semiconductor structure 13 in the distribution direction of the striped doped regions 14 of the opposite conductivity type is defined as D, where D1 ≤ D ≤ D1 + D2 + D3. In this case, as shown in Figure 3, once the layout of the back contact battery is determined, D1, D2 and D3 become fixed values. Based on this, if at least a portion of the conductive semiconductor structure 13 belongs to the first doped region and the second doped region, respectively, and is located between two adjacent striped doped regions 14, then if D is equal to D1, the conductive semiconductor structure 13 located between two adjacent striped doped regions 14 of the opposite conductivity type can be electrically contacted by the two adjacent striped doped regions 14 of the opposite conductivity type in the arrangement direction of the striped doped regions 14 of the opposite conductivity type, ensuring that the first doped region 11 and the second doped region are electrically connected via the conductive semiconductor structure 13. At the same time, the area of ​​the orthographic projection on the non-light-receiving side of the conductive semiconductor structure 13 can be precisely adjusted, ensuring that the corresponding hot spot risk and operating efficiency during normal operation of the back-contact battery both precisely meet the operating requirements. Next, as shown in Figures 7 to 9, the value of D may be greater than D1 and less than or equal to D1 + D2 + D3. In this case, the conductive semiconductor structure 13 can be located not only between two adjacent stripe-shaped doped regions 14 of opposite conductivity types, but also on at least one of two adjacent stripe-shaped doped regions 14 of opposite conductivity types. This prevents the requirements for etching accuracy from becoming too strict in order to obtain a conductive semiconductor structure 13 located only between two adjacent stripe-shaped doped regions 14 of opposite conductivity types, and reduces the difficulty of etching.Furthermore, when the second conductive semiconductor portion of the conductive semiconductor structure 13 is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, the size of the effective electrical contact area can be adjusted by adjusting the value of D. This is advantageous for balancing the reverse breakdown voltage and leakage loss of the back-contact battery, and is beneficial for the back-contact battery to have good operating performance.

[0145] Preferably, the value of D is

number

number

[0146] For example, as shown in Figure 4, when at least a portion of the conductive semiconductor structure 13 is located between a striped doped region 14 included in one of the first and second doped regions and an adjacent connection region 15 included in the other of the first and second doped regions, the width of the connection region 15 belonging to one of the first and second doped regions and in contact with the conductive semiconductor structure 13 is defined as W1, and the length of the striped doped region 14 belonging to the other of the first and second doped regions and in contact with the conductive semiconductor structure 13 is defined as W2. In addition, in the width direction of the space region, the length of the conductive semiconductor structure 13 is D, where D1 ≤ D ≤ D1 + W1 + W2. In this case, once the layout of the back contact battery is determined, D1, W1 and W2 become fixed values. Based on this, if at least a portion of the conductive semiconductor structure 13 is located between a striped doped region 14 included in one of the first doped region and the second doped region and an adjacent connection region 15 included in the other of the first doped region and the second doped region, then if D is equal to D1, the conductive semiconductor structure 13 located between the adjacent striped doped region 14 and the connection region 15, which are of the opposite conductivity type, can be electrically contacted with the adjacent striped doped region 14 and connection region 15, respectively, in the arrangement direction of the first doped region and the second doped region, ensuring that the first doped region and the second doped region are electrically connected via the conductive semiconductor structure 13. At the same time, the area of ​​the orthographic projection on the non-light-receiving side of the conductive semiconductor structure 13 can be precisely adjusted, ensuring that the corresponding hot spot risk and operating efficiency during normal operation of the back-contact battery both precisely meet the operating requirements.Next, as shown in Figure 10, the value of D may be greater than D1 and less than or equal to W1 + W2 + D1. In this case, the conductive semiconductor structure 13 can be located not only between adjacent stripe-shaped doped regions 14 and connection regions 15 of the opposite conductivity type, but also on at least one of adjacent stripe-shaped doped regions 14 and connection regions 15 of the opposite conductivity type. This prevents the requirements for etching accuracy from becoming too strict in order to obtain a conductive semiconductor structure 13 located only between adjacent stripe-shaped doped regions 14 and connection regions 15 of the opposite conductivity type, thereby reducing the difficulty of etching. Furthermore, when the second conductive semiconductor portion of the conductive semiconductor structure 13 is electrically in contact with the portion of the first doped region and / or the second doped region opposite to the semiconductor substrate, the size of the effective electrical contact area can be adjusted by adjusting the value of D, which is advantageous for balancing the reverse breakdown voltage and leakage loss of the back-contact battery, and is advantageous for the back-contact battery to have good operating performance.

[0147] Preferably,

number

number

[0148] The corresponding D and W values ​​of the conductive semiconductor structure can be determined according to the layout and size relationship of the back contact battery in the actual application scenario, and are not specifically limited here.

[0149] Specifically, as an example, if the second conductive semiconductor portion is positioned above the portion of the striped dope region opposite to the semiconductor substrate in the width direction of the corresponding striped dope region, the arrangement width of the second conductive semiconductor portion in the width direction of the striped dope region may be 1 / 10 or more of the width of the corresponding striped dope region and less than 1 / 2 of the width of the corresponding striped dope region. In this case, the carriers collected by the first dope region need to be guided out via an electrode structure that is in ohmic contact with itself. Based on this, in the width direction of the striped dope region, a portion of the striped dope region included in the first dope region in its extending direction needs to be in direct ohmic contact with the electrode structure, and this ohmic contact region occupies a certain width. In this case, if the arrangement width of the second conductive semiconductor portion is 1 / 10 or more of the width of the corresponding striped dope region and less than 1 / 2 of the width of the corresponding striped dope region, it is possible to prevent the requirements for etching accuracy from becoming stricter in order to form a second conductive semiconductor portion with a small arrangement width due to the small arrangement width X1 of the second conductive semiconductor portion, and to reduce the difficulty of etching. At the same time, if the corresponding arrangement method for the second conductive semiconductor portion is electrical contact, the corresponding effective electrical contact area of ​​the conductive semiconductor structure becomes smaller due to the small arrangement width X1, which prevents a decrease in the effect of reducing the risk of hot spots due to the arrangement of the conductive semiconductor structure in a back-contact battery. Furthermore, it is possible to prevent the electrode structure from being unable to make ohmic contact with the stripe-shaped doped region included in the first doped region due to the large arrangement width X1 of the second conductive semiconductor portion, and to ensure that the current collected by the first doped region is led out through the electrode structure, which is advantageous for the formation of photocurrent.

[0150] Next, if the first doped region and the second doped region are distributed alternately with spacing between them, as shown in Figures 7 to 9, if the value of D of the conductive semiconductor structure 13 is greater than D1, or as shown in Figure 10, if the value of W is greater than D2 + 2 × D1 or if the value of W is greater than D3 + 2 × D1, the conductive semiconductor structure 13 is further positioned above the portion of the first doped region and / or the second doped region opposite to the semiconductor substrate. In this case, it may affect the size of the corresponding effective electrical contact area of ​​the conductive semiconductor structure 13. Therefore, the position of the conductive semiconductor structure 13 and the ratio and specific size of the position size, width W, and side effective electrical contact height Z of the conductive semiconductor structure 13 can be determined according to the requirements for the size of the effective electrical contact area in the actual application scenario, and are not specifically limited here.

[0151] For example, when the second conductive semiconductor portion is arranged on a corresponding striped doped region in the width direction of the striped doped region, as shown in Figures 7 to 9, if the second conductive semiconductor portion 18 is arranged on a striped doped region 14 included in the first doped region, then 0.1 × D2 ≤ X1 < 0.5 × D2, and / or, if the second conductive semiconductor portion 18 is arranged on a striped doped region 14 included in the second doped region, then 0.1 × D3 ≤ X1 < 0.5 × D3. For example, if the second conductive semiconductor portion 18 is arranged on a striped doped region 14 included in the first doped region, X1 may be equal to 0.1 × D2, 0.2 × D2, 0.25 × D2, 0.3 × D2, 0.35 × D2, or 0.4 × D2, etc. For example, when the second conductive semiconductor portion 18 is placed on a striped doped region 14 included in the second doped region, X1 may be equal to 0.1 × D3, 0.2 × D3, 0.25 × D3, 0.3 × D3, 0.35 × D3, or 0.4 × D3, etc. In this case, the example will be described when the conductive semiconductor structure 13 is placed on a striped doped region 14 included in the first doped region in the width direction of the striped doped region 14, and the carriers collected by the first doped region need to be guided out via an electrode structure that is in ohmic contact with itself. Based on this, in the width direction of the striped doped region 14, a portion of the striped doped region 14 included in the first doped region in its extending direction needs to be in direct ohmic contact with the electrode structure, and this ohmic contact region occupies a certain width. In this case, if 0.1 × D2 ≤ X1 < 0.5 × D2, the small placement width X1 of the second conductive semiconductor portion 18 prevents the requirements for etching accuracy from becoming too stringent in order to form a second conductive semiconductor portion 18 with a small placement width, thereby reducing the difficulty of etching. At the same time, if the corresponding placement method of the second conductive semiconductor portion 18 is electrical contact, the small placement width X1 also reduces the corresponding effective electrical contact area of ​​the conductive semiconductor structure, which prevents a decrease in the effect of reducing the risk of hot spots due to the placement of the conductive semiconductor structure in a back-contact battery.Furthermore, the large arrangement width X1 of the second conductive semiconductor portion 18 prevents the electrode structure from being unable to make ohmic contact with the stripe-shaped doped region 14 included in the first doped region, and ensures that the current collected by the first doped region is led out through the electrode structure, which is advantageous for the formation of photocurrent. Also, the beneficial effect of 0.1×D3≦X1<0.5×D3 is similar to the beneficial effect of 0.1×D2≦X1<0.5×D2, and will not be explained again here.

[0152] For example, when the corresponding arrangement of the second conductive semiconductor portion is an electrical contact, X1 ≤ W ≤ 40 × X1, and / or, when the first doped region and the second doped region are electrically coupled via the conductive semiconductor structure, the effective electrical contact height on the side is Z, where 1 / 1500 of X1 ≤ Z ≤ 1 / 400 of X1. For example, when the corresponding arrangement of the second conductive semiconductor portion is an electrical contact, W may be equal to X1, 5 × X1, 10 × X1, 15 × X1, 20 × X1, 30 × X1, or 40 × X1, etc. For example, when the corresponding arrangement of the second conductive semiconductor portion is an electrical contact, Z may be equal to 1 / 1500 of X1, 1 / 1000 of X1, 1 / 800 of X1, 1 / 600 of X1, or 1 / 400 of X1. In this case, if the corresponding arrangement of the second conductive semiconductor portion is an electrical contact, the effective electrical contact area between the conductive semiconductor structure and each of the first and second doped regions includes not only the contact area between the sidewall of the conductive semiconductor structure and the first or second doped region, but also the contact area between the second conductive semiconductor portion and the corresponding stripe-shaped doped region. Based on this, the size of the effective electrical contact area can be adjusted by adjusting at least one value of X1, W, and Z, which affects the corresponding reverse breakdown voltage and the leakage current in the normal operating state of the back-contact battery. In this case, if X1 ≤ W ≤ 40 × X1, the width W of the conductive semiconductor structure has a large selectable range, and the corresponding reverse breakdown voltage and the leakage current in the normal operating state of the back-contact battery can be adjusted by adjusting the width W of the conductive semiconductor structure, which is advantageous for improving the applicability of the back-contact battery provided in the embodiment of this application to different application scenarios. Furthermore, by keeping W within the above range, it is possible to prevent the requirement for high manufacturing precision of the conductive semiconductor structure from increasing due to a small W, which is advantageous for reducing the difficulty of manufacturing the back-contact battery. Furthermore, because W is small, the setting values ​​of X1 and / or Z can be increased to reduce the corresponding reverse breakdown voltage of the back contact battery within the operating requirements, thereby preventing an impact on the formation quality of the electrode structure, etc., and improving the yield of the back contact battery.At the same time, it is possible to prevent the corresponding leakage current of a single conductive semiconductor structure from becoming large due to a large W, and to ensure that the back-contact battery has high operating performance during normal operation. Furthermore, the beneficial effect of X1 1 / 1500 ≤ Z ≤ X1 1 / 400 is similar to the beneficial effect of X1 ≤ W ≤ 40 × X1, and will not be explained again here.

[0153] For example, when the corresponding arrangement of the second conductive semiconductor part is an electrical contact, 0.03 mm ≤ X1 ≤ 0.2 mm and / or 0.03 mm ≤ W ≤ 8 mm. For example, when the corresponding arrangement of the second conductive semiconductor part is an electrical contact, X1 may be equal to 0.03 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.18 mm, or 0.2 mm, etc. For example, when the corresponding arrangement of the second conductive semiconductor part is an electrical contact, W may be equal to 0.03 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm, etc. In this case, by keeping X1 within the above range, it is possible to prevent the manufacturing precision requirements from increasing due to a small X1, and to reduce the difficulty of manufacturing back-contact batteries. It is also possible to prevent the effective electrical contact area of ​​the conductive semiconductor structure from decreasing due to a small X1, thus preventing a reduction in the hot spot risk reduction effect of the arrangement of the conductive semiconductor structure in back-contact batteries. Furthermore, because X1 is large, the width of the portion reserved for ohmic contact with the electrode structure in the width direction of the stripe-shaped doped region becomes smaller, increasing the difficulty of manufacturing the electrode structure and / or preventing increased contact resistance between the electrode structure and the stripe-shaped doped region, which is advantageous for improving the yield of back-contact batteries and the contact performance between the electrode structure and the stripe-shaped doped region. The beneficial effects of W being within the above range can be found in the preceding paragraph and will not be explained again here.

[0154] For example, if the corresponding arrangement of the second conductive semiconductor portion is insulating, then W 1 / 160000 ≤ Z ≤ W 1 / 25. For instance, in this case, the lateral effective electrical contact height Z may be equal to W 1 / 160000, W 1 / 15000, W 1 / 12000, W 1 / 10000, or W 1 / 25, etc. In this case, regardless of whether the conductive semiconductor structure is positioned on at least one of the first doped region and the second doped region, the effective electrical contact area between the conductive semiconductor structure and each of the first and second doped regions is only the effective electrical contact area between the lateral surfaces of each of the first and second doped regions and the conductive semiconductor structure, i.e., the product of W and Z. In this case, by adjusting the values ​​of W and Z, the reverse breakdown voltage and leakage current during normal operation of the back-contact battery can be adjusted, which is advantageous for improving the applicability of the back-contact battery provided in the embodiments of this application to different application scenarios. In other words, if W and Z satisfy the above-mentioned range of magnitude relationships, it is possible to prevent the effective electrical contact area from becoming large due to an inappropriate setting of the ratio relationship between W and Z, thereby preventing the leakage current in the normal operating state of the back-contact battery from becoming large and ensuring that the back-contact battery has high operating performance. It is also possible to prevent the effective electrical contact area from becoming small due to an inappropriate setting of the ratio relationship between W and Z, thereby preventing a small reduction in the reverse breakdown voltage of the back-contact battery and ensuring a low risk of hot spots in the back-contact battery.

[0155] For example, the lateral effective electrical contact height Z may satisfy the condition 0.00005 mm ≤ Z ≤ 0.002 mm. For instance, the lateral effective electrical contact height Z may be 0.00005 mm, 0.0001 mm, 0.0002 mm, 0.0003 mm, 0.0004 mm, 0.0005 mm, 0.001 mm, or 0.002 mm. In this case, in practical use, considering the carrier isolation capability and the amount of consumable material used, the first and second doped regions included in the back contact battery usually have a reasonable range of thickness (or depth). Furthermore, the magnitude of the lateral effective electrical contact height Z affects the effective electrical contact area between the conductive semiconductor structure and each of the first and second doped regions, and affects the magnitude of the leakage current in the first and second doped regions that are locally conductive through a single conductive semiconductor structure. In this case, by keeping the lateral effective electrical contact height Z within the above range, it is possible to prevent a poor balance between the risk of hot spots in the back-contact battery and the operating efficiency during normal operation, which can occur due to the corresponding effective electrical contact area of ​​the conductive semiconductor structure being too large or too small. Furthermore, it is possible to prevent an increase in the amount of manufacturing material used for the conductive semiconductor structure due to a large lateral effective electrical contact height Z, which is advantageous in suppressing the manufacturing cost of the back-contact battery.

[0156] For example, when the second conductive semiconductor portion is located on a corresponding stripe-doped region in the extending direction of the stripe-doped region, as shown in Figure 10, if the second conductive semiconductor portion 18 is located on a stripe-doped region 14 included in the first doped region, then 0.1 × D2 ≤ X2 ≤ 1.2 × D2, and / or, if the second conductive semiconductor portion 18 is located on a stripe-doped region 14 included in the second doped region, then 0.1 × D3 ≤ X2 ≤ 1.2 × D3. For example, if the second conductive semiconductor portion 18 is located on a stripe-doped region 14 included in the first doped region, X2 may be equal to 0.1 × D2, 0.3 × D2, 0.6 × D2, 0.9 × D2, D2, or 1.2 × D2, etc. For example, when the second conductive semiconductor portion 18 is placed on a striped doped region 14 included in the second doped region, X2 may be equal to 0.1 × D3, 0.3 × D3, 0.6 × D3, 0.9 × D3, D3, or 1.2 × D3, etc. In this case, the example will be explained when the conductive semiconductor structure 13 is placed on a striped doped region 14 included in the first doped region in the extending direction of the striped doped region 14. As mentioned above, the carriers collected by the first doped region need to be guided out via an electrode structure that is in ohmic contact with itself. Furthermore, the extending length of the electrode structure on the striped doped region 14 included in the first doped region affects the contact resistance between itself and the first doped region, and whether the carriers collected by each part of the striped doped region 14 included in the first doped region can be guided out via the electrode structure in a timely manner. Based on this, if 0.1 × D2 ≤ X2 ≤ 1.2 × D2, it is possible to prevent the requirements for etching accuracy from becoming too strict in order to form a conductive semiconductor structure 13 with a small arrangement width X2 due to the small arrangement width X2 of the second conductive semiconductor part 18, which is advantageous in reducing the difficulty of manufacturing back contact batteries. At the same time, if the corresponding arrangement method of the second conductive semiconductor part 18 is electrical contact, the corresponding effective electrical contact area of ​​the conductive semiconductor structure also becomes small due to the small arrangement width X2, which prevents a decrease in the effect of reducing the risk of hot spots due to the arrangement of the conductive semiconductor structure in back contact batteries.Furthermore, due to the large arrangement width X2 of the second conductive semiconductor portion 18, the distance between the end of the electrode structure and the edge of the stripe-shaped doped region 14 increases in the extending direction of the stripe-shaped doped region 14. This prevents carriers collected by the longitudinal edge of the stripe-shaped doped region 14 from being released in a timely manner, thus ensuring that the back contact battery has good operating performance. The beneficial effects of 0.1×D3≦X2≦1.2×D3 can be seen in the analysis of the beneficial effects of 0.1×D2≦X2≦1.2×D2, and will not be explained again here.

[0157] For example, as shown in Figure 10, in the extending direction of the stripe-shaped doped region 14, the arrangement width X3 of the second conductive semiconductor portion 18 may satisfy 0.1 × W1 ≤ X3 ≤ 0.3 × W1. For example, X3 may be equal to 0.1 × W1, 0.12 × W1, 0.14 × W1, 0.16 × W1, 0.18 × W1, 0.2 × W1, 0.24 × W1, 0.28 × W1, or 0.3 × W1, etc. In this case, in practice, the electrode structure may be formed above the connection region 15, and may even be in ohmic contact with the connection region 15. Based on this, the portion of the electrode structure above the connection region 15 needs to occupy a certain width of the connection region 15. In this case, if 0.1 × W1 ≤ X3 ≤ 0.3 × W1, the small arrangement width X3 of the second conductive semiconductor portion 18 prevents the requirements for etching accuracy from becoming too strict in order to form a conductive semiconductor structure 13 with a small arrangement width, thereby reducing the difficulty of etching. At the same time, if the corresponding arrangement method of the second conductive semiconductor portion 18 is electrical contact, the small arrangement width X3 also reduces the corresponding effective electrical contact area of ​​the conductive semiconductor structure, which prevents a decrease in the effect of reducing the risk of hot spots due to the arrangement of the conductive semiconductor structure in a back-contact battery. Furthermore, a large X3 prevents the formation of an electrode structure on a small-width region exposed outside the second conductive semiconductor portion 18 of the connection region 15, thereby reducing the difficulty of manufacturing the electrode structure. It also prevents the corresponding transmission resistance of the electrode structure from becoming too high due to the small formation width of the electrode structure on the connection region 15, ensuring that the electrode structure has good transmission performance.

[0158] Regarding the thickness H of the conductive semiconductor structure, as mentioned above, the magnitude of the value of H may affect the magnitude of the effective electrical contact height Z on the side. Therefore, it can be determined according to the specific formation process of the conductive semiconductor structure and the effective electrical contact area between the conductive semiconductor structure and the first doped region and the second doped region in the actual application scenario, and is not specifically limited here. As shown in Figure 6, when the conductive semiconductor structure 13 is integrally continuous with the second doped region 12, it can be understood that the thickness of the conductive semiconductor structure 13 is equal to the thickness of the second doped region 12. As shown in Figure 5, when the conductive semiconductor structure 13 is integrally continuous with the first doped region 11, it can be understood that the thickness of the conductive semiconductor structure 13 is equal to the thickness of the first doped region 11.

[0159] From a quantitative standpoint, the back-contact battery provided in the embodiments of this application may include only one conductive semiconductor structure. Alternatively, as shown in Figures 50 and 51, the back-contact battery may include a plurality of conductive semiconductor structures 13. Furthermore, adjacent conductive semiconductor structures 13 are spaced apart. In this case, it is possible to prevent a large local leakage current from occurring between the first doped region and the second doped region due to contact between adjacent different conductive semiconductor structures 13.

[0160] Here, if the back contact battery includes multiple conductive semiconductor structures, the orthographic areas on the non-light-receiving side of the different conductive semiconductor structures may or may not be equal. Here, as shown in Figures 50 and 51, if the orthographic areas on the non-light-receiving side of the different conductive semiconductor structures 13 are equal, it is advantageous to make the magnitude of the corresponding leakage currents the same after the first doped region and the second doped region are electrically connected to the different conductive semiconductor structures 13, and is advantageous to make the reverse breakdown voltages of the built-in diodes located in different regions between the first doped region and the second doped region equal, preventing the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded, and further reducing the risk of hot spots in solar modules including the back contact battery provided in the embodiments of this application.

[0161] Furthermore, if the width W of the conductive semiconductor structure satisfies 0.5 × D1 ≤ W ≤ 6 × D1, it can be understood that the number of conductive semiconductor structures included in the back contact battery affects the sum of the orthographic areas on the non-light-receiving side of all conductive semiconductor structures, and thus affects the operating efficiency of the solar module including the back contact battery in the normal voltage range, as well as the magnitude of the reverse breakdown voltage of the back contact battery. Therefore, depending on the requirements of the two cases mentioned above in actual application scenarios, the number of conductive semiconductor structures included in the back contact battery and the area ratio of the sum of the orthographic areas on the non-light-receiving side of all conductive semiconductor structures to the non-light-receiving side can be determined.

[0162] For example, let S3 be the sum of the orthographic areas on the non-photosensitive side of the portion located between the first doped region and the second doped region of all conductive semiconductor structures, and let S2 be the area of ​​the non-photosensitive surface. The ratio of S3 to S2 may be between 0.002% and 20%. For example, the ratio of S3 to S2 may be 0.002%, 0.01%, 0.1%, 1%, 5%, 10%, 15%, or 20%, etc. In this case, a small ratio of S3 to S2 prevents the orthographic area on the non-photosensitive side of a single conductive semiconductor structure from becoming small and / or the number of conductive semiconductor structures arranged on the non-photosensitive side from becoming small. This ensures that the reverse breakdown voltage of a back-contact battery can be reduced to a range that satisfies the operating requirements by arranging conductive semiconductor structures in a reasonable number and with reasonable orthographic areas. Furthermore, the large ratio of S3 to S2 can prevent the orthographic area of ​​a single conductive semiconductor structure on the non-light-receiving side from increasing and / or the number of conductive semiconductor structures arranged on the non-light-receiving side from increasing, thus preventing a decrease in the operating efficiency of the solar module, including the back contact battery, in the forward voltage region.

[0163] Regarding the number of conductive semiconductor structures arranged on the non-light-receiving side, as shown in Figures 52 to 55, if the size of each conductive semiconductor structure 13 is constant, it can be understood that the more conductive semiconductor structures 13 formed on the non-light-receiving side there are, the larger the total area of ​​the orthographic projection of the conductive semiconductor structures 13 on the non-light-receiving side becomes. Next, within a certain range, as the number of conductive semiconductor structures 13 increases, the corresponding reverse breakdown voltage of the back contact battery gradually decreases. However, beyond the corresponding range, even if more conductive semiconductor structures 13 are arranged on the non-light-receiving side, the corresponding reverse breakdown voltage of the back contact battery changes only slightly, and eventually stops changing. When the number of conductive semiconductor structures 13 increases to a large range, the operating efficiency of the back contact battery decreases as the leakage current increases. Based on this, the number of conductive semiconductor structures can be determined according to the division of the back contact battery, the size of the conductive semiconductor structures 13, and the requirements for the reverse breakdown voltage and operating efficiency of the back contact battery in actual application scenarios.

[0164] For example, if the back contact battery is a back contact battery, the number of conductive semiconductor structures included in the back contact battery may be between 30 and 8000. For instance, if the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures included in the back contact battery may be 30, 300, 400, 450, 500, 800, 1000, 1500, 2000, 2500, 3000, or 8000. When the above technical solution is adopted, if the back contact battery is an integrated back contact battery, setting the number of conductive semiconductor structures included in the back contact battery to between 30 and 8000 prevents a reduction in the corresponding reverse breakdown voltage of the back contact battery due to a small number of conductive semiconductor structures, and ensures that the hot spot risk of the back contact battery is reduced within the range of operational requirements. Furthermore, it is possible to prevent the operational efficiency of the solar module including the back contact battery provided in the embodiment of this application from being reduced due to the arrangement of many conductive semiconductor structures.

[0165] For example, if the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures included in the back contact battery may be between 30 / N and 8000 / N, where N is a positive integer of 2 or more. For instance, if the back contact battery is a 1 / 2 split back contact battery, the number of conductive semiconductor structures included in the back contact battery may be 15, 120, 150, 175, 200, 300, 500, 800, 1000, 1200, 1500, or 1650, etc. The beneficial effects in this case can be seen in the analysis of the beneficial effects of having 30 or more and 8000 or less conductive semiconductor structures included in the back contact battery when it is an integrated back contact battery, as described above, and will not be explained again here.

[0166] Specifically, in practical applications, the number of conductive semiconductor structures included in a back contact battery can be determined according to the magnitude of the ratio of the width W of the conductive semiconductor structure to D1.

[0167] For example, if the ratio of W to D1 is 0.5 or more and 2 or less, and the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures included in the back contact battery may be 30 or more and 2000 or less. If the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures included in the back contact battery may be 30 / N or more and 2000 / N or less.

[0168] For example, if the ratio of W to D1 is greater than 2 and 3 or less, and the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures included in the back contact battery may be between 350 and 1530. If the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures included in the back contact battery may be between 350 / N and 1530 / N.

[0169] Furthermore, as mentioned above, if the second conductive semiconductor portion of the conductive semiconductor structure is further positioned above the portion of the first doped region and the portion of the second doped region opposite to the semiconductor substrate, the size of the corresponding effective electrical contact area of ​​the conductive semiconductor structure changes depending on the arrangement method of the conductive semiconductor structure. As a result, this may affect the reverse breakdown voltage and the magnitude of the leakage current during normal operation of the back-contact battery. Based on this, the number of conductive semiconductor structures positioned on the non-light-receiving side in different arrangement methods can be determined according to the requirements for the reverse breakdown voltage and the magnitude of the leakage current during normal operation of the back-contact battery in actual application scenarios, and this is not specifically limited here.

[0170] For example, if the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, and the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures arranged on the non-light-receiving surface side may be 30 or more and 4000 or less, and if the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures arranged on the non-light-receiving surface side may be 30 / N or more and 4000 / N or less, where N is a positive integer of 2 or more. For example, if the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, and the back contact battery is a 1 / 2 split back contact battery, the number of conductive semiconductor structures arranged on the non-light-receiving surface side may be 15, 100, 300, 500, 1000, 1500, or 2000, etc. In this case, all other factors being equal, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is larger when the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate than when the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate.Based on this, when the second conductive semiconductor portion of the conductive semiconductor structure is electrically in contact with the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, by keeping the number of conductive semiconductor structures arranged on the non-light-receiving surface side within the above range, it is possible to prevent the reduction in the corresponding reverse breakdown voltage of the back contact battery from becoming small due to a small number of conductive semiconductor structures, and to ensure that the risk of hot spots in the back contact battery is reduced within the range of operating requirements. Furthermore, it is also possible to prevent the operating efficiency of the solar module including the back contact battery provided in the embodiment of this application from becoming low due to the arrangement of many conductive semiconductor structures.

[0171] For example, if the second conductive semiconductor portion of the conductive semiconductor structure is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, and the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures arranged on the non-light-receiving surface side may be 5000 or more and 8000 or less, and if the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures arranged on the non-light-receiving surface side may be 5000 / N or more and 8000 / N or less, where N is a positive integer of 2 or more. For example, if the second conductive semiconductor portion of the conductive semiconductor structure is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, and the back contact battery is a 1 / 2 split back contact battery, the number of conductive semiconductor structures arranged on the non-light-receiving surface side may be 2500, 2800, 3000, 3200, 3500, 3800, or 4000, etc. In this case, all other factors being equal, the corresponding effective electrical contact area of ​​the conductive semiconductor structure is smaller when the second conductive semiconductor portion of the conductive semiconductor structure is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate than when the second conductive semiconductor portion of the conductive semiconductor structure is in electrical contact above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate. Based on this, if the second conductive semiconductor portion of the conductive semiconductor structure is insulated above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate, the reverse breakdown voltage of the back contact battery can be reduced to within the target range by rationally arranging a large number of conductive semiconductor structures on the non-light-receiving surface side.Based on this, by keeping the number of conductive semiconductor structures arranged on the non-light-receiving side within the above range, it is possible to prevent the reduction in the corresponding reverse breakdown voltage of the back contact battery from becoming small due to a small number of conductive semiconductor structures, and to ensure that the risk of hot spots in the back contact battery is reduced within the range of operational requirements. Furthermore, it is also possible to prevent the operation efficiency of the solar module including the back contact battery provided in the embodiment of this application from becoming low due to the arrangement of many conductive semiconductor structures.

[0172] Hereinafter, with reference to Figure 56 and Table 1, four specific embodiments and one comparative example of the back-contact battery provided in the embodiments of this application will be described. As shown in Figure 11, in the back-contact battery corresponding to Embodiment 1, second conductive semiconductor portions 18 are arranged on both sides in the width direction of each stripe-shaped doped region 14, with a total of 6732 second conductive semiconductor portions 18, and the sum of the corresponding effective electrical contact areas of all conductive semiconductor structures 13 on the non-light-receiving surface side is 242.4 mm². 2 That is the case.

[0173] In the back-contact battery corresponding to Example 2, the conductive semiconductor structure is arranged on both sides of the electrical connection point (where the electrode structure and a series connecting member such as a ribbon are connected) in the direction of extension of the stripe-shaped doped region, the number of second conductive semiconductor parts is 672, and the total effective electrical contact area of ​​all corresponding conductive semiconductor structures on the non-light-receiving surface side is 31.2 mm². 2 That is the case.

[0174] Example 3 is based on Example 1, with seven stripe-shaped doped regions in the width direction of the stripe-shaped doped region, followed by the next stripe-shaped doped region, and second conductive semiconductor parts are arranged on both sides in the width direction. The number of second conductive semiconductor parts is 884, and the total effective electrical contact area of ​​all conductive semiconductor structures on the non-light-receiving surface side is 31.8 mm². 2 That is the case.

[0175] Example 4 is based on Example 3, but the corresponding arrangement area of ​​the second conductive semiconductor portion is reduced. In this case, the number of arrangements of the second conductive semiconductor portion remains 884, but the sum of the corresponding effective electrical contact areas of all conductive semiconductor structures on the non-light-receiving surface side is 7.96 mm². 2 That is the case.

[0176] In the comparative example, as shown in Figure 1, the first doped region and the second doped region are completely separated.

[0177] Table 1: Comparison of parameters of back contact batteries corresponding to Examples 1-4 [Table 1]

[0178] As can be seen from the data shown in Figure 56 and Table 1, because conductive semiconductor structures are arranged, the maximum reverse voltage of the back contact batteries corresponding to Examples 1 to 4 is smaller than the maximum reverse voltage of the comparative examples. Also, because the number of conductive semiconductor structures in Example 3 is less than the number of conductive semiconductor structures arranged in Example 1, the maximum reverse voltage and hot spot temperature of the back contact battery corresponding to Example 3 are greater than the maximum reverse voltage and hot spot temperature of the back contact battery corresponding to Example 1. Furthermore, because the arrangement area of ​​conductive semiconductor structures in Example 4 is smaller than the arrangement area of ​​conductive semiconductor structures in Example 3, the maximum reverse voltage of the back contact battery corresponding to Example 4 is greater than the maximum reverse voltage of the back contact battery corresponding to Example 3.

[0179] Regarding the distribution of different conductive semiconductor structures on the non-light-receiving side, the position of each conductive semiconductor structure on the non-light-receiving side can be set randomly. Preferably, as shown in Figures 50 and 51, the different conductive semiconductor structures 13 are uniformly distributed on the non-light-receiving side. In this case, it is advantageous to equalize the reverse breakdown voltage of the built-in diode formed after arranging the conductive semiconductor structure 13 between different regions of the first doped region and corresponding regions of the second doped region, preventing the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded, and further reducing the risk of hot spots in solar modules including back contact batteries provided in embodiments of this application.

[0180] In practical applications, Figures 57 to 62 show several selectable distribution patterns of the conductive semiconductor structure 13 within different unit regions on the non-light-receiving surface. The different conductive semiconductor structures 13 can be uniformly distributed on the non-light-receiving surface in at least several configurations shown in Figures 25 to 30. The embodiments of this application do not specifically limit the distribution patterns of the different conductive semiconductor structures 13 on the non-light-receiving surface.

[0181] Exemplary, as shown in Figures 50 and 51, different conductive semiconductor structures 13 may be distributed in a matrix on the non-light-receiving surface side. Adjacent rows of the matrix-distributed conductive semiconductor structures 13 are aligned or arranged in a staggered pattern. Here, in the matrix-distributed conductive semiconductor structures 13, one conductive semiconductor structure 13 in each row and the corresponding conductive semiconductor structure 13 in the adjacent row may be aligned or arranged in a staggered pattern. In the matrix-distributed conductive semiconductor structures 13, at least two opposing conductive semiconductor structures 13 in each row and the corresponding at least two opposing conductive semiconductor structures 13 in the adjacent row may be aligned or arranged in a staggered pattern.

[0182] In this case, the distribution of the different conductive semiconductor structures 13 on the non-light-receiving side is regular, and there are two distribution forms between adjacent rows of the matrix-distributed conductive semiconductor structures 13: alignment and staggered arrangement. This is advantageous in reducing the difficulty of manufacturing the conductive semiconductor structures 13, while also being advantageous in uniformly distributing the conductive semiconductor structures 13 on the non-light-receiving side, further preventing the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded.

[0183] Here, if adjacent rows of conductive semiconductor structures distributed in a matrix are arranged in a staggered pattern, the displacement distance L between two adjacent rows of conductive semiconductor structures may be any value greater than 0 and less than the distance L1 between the geometric centers of two adjacent conductive semiconductor structures within the same row.

[0184] For example, as shown in Figure 51, when adjacent rows of conductive semiconductor structures 13 distributed in a matrix are arranged in a staggered pattern, the displacement distance L between two adjacent rows of conductive semiconductor structures 13 is equal to half the distance L1 between the geometric centers of two adjacent conductive semiconductor structures 13 within the same row. In this case, it is advantageous to make the distribution density approximately the same between different regions of the first doped region 11 and the corresponding region of the second doped region 12 of the conductive semiconductor structure 13, and prevents the possibility of battery burnout due to localized heat concentration when the back contact battery is shielded due to a long region physically separated between the first doped region 11 and the second doped region 12 by an insulating trench or insulating material.

[0185] In practical applications, as shown in Figure 63, the back-contact battery may further include a surface passivation layer 19 and an electrode structure 20. The surface passivation layer 19 is formed on at least a first doped region 11, a second doped region 12, and a conductive semiconductor structure 13. The electrode structure 20 penetrates the surface passivation layer 19 and is in ohmic contact with the first doped region 11 and the second doped region 12, respectively. The portion of the electrode structure 20 electrically coupled to the first doped region 11 and the portion of the electrode structure 20 electrically coupled to the second doped region 12 are insulated from each other.

[0186] Specifically, the embodiments of this application do not specifically limit the material and thickness of the surface passivation layer and electrode structure, as long as they are applicable to the back-contact battery provided in the embodiments of this application. Also, as shown in Figure 63, the second conductive semiconductor portion of the conductive semiconductor structure 13 may be positioned above the portion of the first doped region 11 and / or the second doped region 12 opposite to the semiconductor substrate. In this case, the second conductive semiconductor portion of the conductive semiconductor structure 13 occupies a certain area above the portion of the first doped region 11 and / or the second doped region 12 opposite to the semiconductor, which may affect the manufacturing of the electrode structure 20. Based on this, the manufacturing precision of the electrode structure 20, the contact performance of the electrode structure 20, and the corresponding effective electrical contact area of ​​the conductive semiconductor structure 13 can be determined according to the requirements of the actual application, and are not specifically limited here.

[0187] For example, the minimum distance D4 between the electrode structure and the portion of the surface passivation layer covering the conductive semiconductor structure in a direction parallel to the non-light-receiving surface may be 30 μm or more and 250 μm or less. For instance, the minimum distance D4 between the electrode structure and the portion of the surface passivation layer covering the conductive semiconductor structure in a direction parallel to the non-light-receiving surface may be 30 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 220 μm, or 250 μm, etc. In practical use, there is a certain processing error in the equipment used to manufacture the electrode structure, so a certain deviation often occurs between the target formation range and the actual formation range of the electrode structure. Based on this, by setting the minimum distance D4 between the electrode structure and the portion of the surface passivation layer covering the conductive semiconductor structure within the above range, it is possible to prevent at least a part of the electrode structure from being formed above the conductive semiconductor structure due to a small minimum distance D4, thereby preventing carriers collected by the first doped region and / or second doped region from being released in a timely manner. Furthermore, a large minimum distance D4 can prevent the width of the conductive semiconductor structure from becoming smaller due to the large width of the first and second doped regions, ensuring that each conductive semiconductor structure has a relatively large effective electrical contact area, which is advantageous for reducing the reverse breakdown voltage of the back-contact battery.

[0188] In a second aspect, embodiments of this application provide a solar module including a solar cell provided in the first aspect and various realizations thereof.

[0189] The beneficial effects of the second embodiment and its various implementations in the embodiments of this application can be found by referring to the analysis of the beneficial effects of the first embodiment and its various implementations, and will not be described again here.

[0190] In a third aspect, the embodiments of the present application further provide a method for manufacturing a back-contact battery, the method for manufacturing a back-contact battery comprising the following steps.

[0191] First, we provide semiconductor substrates.

[0192] Next, a first doped region and a second doped region are formed on the non-light-receiving side of the semiconductor substrate. The first doped region and the second doped region are alternately distributed at intervals on the non-light-receiving side of the semiconductor substrate, the conductivity types of the first doped region and the second doped region are opposite, and the region located between the first doped region and the second doped region in the arrangement direction of the first doped region and the second doped region is a space region.

[0193] Next, a conductive semiconductor structure is formed on the non-light-receiving side of the semiconductor substrate. The conductive semiconductor structure includes an electrically contacting first conductive semiconductor portion and a second conductive semiconductor portion. The first conductive semiconductor portion is located in a space region, and the conductivity type of the first conductive semiconductor portion is opposite to that of either the first doped region or the second doped region. Only a portion of the first doped region and only a portion of the second doped region are electrically connected to at least the first conductive semiconductor portion. The second conductive semiconductor portion is positioned above the portion of the first doped region and / or the portion of the second doped region opposite to the semiconductor substrate.

[0194] Specifically, the non-light-receiving surface of the semiconductor substrate may have a first region and a second region that are alternately distributed at intervals, and a space region located between the first region and the adjacent second region.

[0195] Here, the boundary between the first region, the second region, and the space region on the non-photosensitive side of the semiconductor substrate is a virtual boundary. Subsequently, a first doped region is formed in the first region, so the range of the first region on the non-photosensitive side can be determined according to the formation range of the first doped region in the actual application scenario. Subsequently, a second doped region is formed in the second region, so the range of the second region on the non-photosensitive side can be determined according to the formation range of the second doped region in the actual application scenario. With respect to the space region, once the ranges of the first and second regions are determined, the range of the space region located between the first region and the adjacent second region is determined. Here, the materials and sizes of the first doped region, the second doped region, and the conductive semiconductor structure can be found in the preceding paragraph and will not be explained again here.

[0196] In the actual manufacturing process, the manufacturing process for forming the first doped region, the second doped region, and the conductive semiconductor structure on the non-light-receiving side of the semiconductor substrate will be explained by dividing it into the following two manufacturing methods.

[0197] Manufacturing method 1: Form a first doped region in the first region.

[0198] In the actual manufacturing process, an intrinsic semiconductor layer may be integrally formed on the non-light-receiving surface side by a process such as chemical vapor deposition, and a doped semiconductor material layer may be obtained by doping the intrinsic semiconductor layer by diffusion or ion implantation. Subsequently, the doped semiconductor material layer is selectively etched by a laser etching process, or by a process such as dry etching or wet etching using the masking action of a corresponding mask plate, to remove the portion corresponding to the second region and the space region of the doped semiconductor material layer, thereby obtaining the first doped region.

[0199] Here, an intrinsic semiconductor layer is doped by a diffusion process, and if the intrinsic semiconductor layer is silicon, a doped silicon glass layer or a conductive doped silicon glass layer is further formed on the side of the first doped region opposite to the semiconductor substrate. Furthermore, if the manufactured back contact battery further includes a passivation layer located between the first doped region and the first region, a passivation material layer may be integrally formed on the non-light-receiving surface side by a process such as chemical vapor deposition before the formation of the intrinsic semiconductor layer. Subsequently, the doped semiconductor material layer is selectively etched, and at the same time, the passivation material layer is selectively etched to obtain a passivation layer located between the first doped region and the semiconductor substrate. Naturally, before the formation of the intrinsic semiconductor layer, a passivation layer may be formed only in the first region by a process such as deposition and etching.

[0200] Next, as shown in Figure 11, a doped semiconductor material layer is integrally formed in the first doped region 11, the space region, and the second region.

[0201] In actual manufacturing processes, an intrinsic semiconductor layer may be integrally formed in the first doped region, the space region, and the second region by processes such as chemical vapor deposition, and the intrinsic semiconductor layer may be doped by diffusion or ion implantation to obtain a doped semiconductor material layer.

[0202] Here, an intrinsic semiconductor layer is doped by a diffusion process, and if the intrinsic semiconductor layer is silicon, a doped silicon glass layer or a conductive doped silicon glass layer is further formed on the side of the doped semiconductor material layer opposite the semiconductor substrate.

[0203] Next, as shown in Figure 11, the doped semiconductor material layer is selectively etched to remove a portion of the doped semiconductor material layer corresponding to a part of the first doped region 11 and a portion corresponding to a part of the space region, thereby forming a second doped region 12 and at least one conductive semiconductor structure 13 with the selectively etched doped semiconductor material layer, wherein the second doped region 12 is located in the second region, the conductivity types of the second doped region 12 and the first doped region 11 are opposite, the conductivity types of the second doped region 12 and the conductive semiconductor structure 13 are the same, only a portion of the first doped region 11 and only a portion of the second doped region 12 are electrically in contact with at least one conductive semiconductor structure 13, the conductive semiconductor structure 13 includes an integrally continuous first conductive semiconductor portion 17 and a second conductive semiconductor portion 18, the first conductive semiconductor portion 17 is located between the first doped region 11 and the second doped region 12, and the second conductive semiconductor portion 18 is positioned above the portion of the first doped region 11 opposite to the semiconductor substrate.

[0204] In practical applications, the doped semiconductor material layer is selectively etched by processes such as laser etching, or dry etching or wet etching using the masking action of a corresponding mask plate, removing portions corresponding to a part of the first region and a part of the space region of the doped semiconductor material layer to obtain a second doped region and a conductive semiconductor structure. Here, the schematic diagram on the left in Figure 11 is a schematic diagram of the selectively etched region (corresponding to the region with the grid in the figure) after the formation of the doped semiconductor material layer. The schematic diagram on the right in Figure 11 is a schematic diagram after the second doped region and conductive semiconductor structure have been formed by selective etching.

[0205] In this manufacturing method, if the material of the first doped region is silicon and diffuses into the first doped region through a diffusion process, it can be understood that after the formation of the conductive semiconductor structure, there is a doped silicon glass layer or a conductive doped silicon glass layer between the second conductive semiconductor portion included in the conductive semiconductor structure and the first doped region directly beneath it. Alternatively, the doped silicon glass layer or conductive doped silicon glass layer on the first doped region may be removed before forming the intrinsic semiconductor layer for manufacturing the second doped region and the conductive semiconductor structure, thereby allowing the second conductive semiconductor portion included in the conductive semiconductor structure and the first doped region directly beneath it to come into direct contact. Alternatively, the doped silicon glass layer or conductive doped silicon glass layer on the first doped region may be removed before forming the intrinsic semiconductor layer for manufacturing the second doped region and the conductive semiconductor structure, and a film layer (e.g., a transparent conductive layer) may be formed according to the actual needs.

[0206] Furthermore, if the manufactured back contact battery further includes passivation located between the second doped region and the second region, after the formation of the first doped region and before the formation of the intrinsic semiconductor layer for manufacturing the doped semiconductor material layer, a passivation material layer may be integrally formed in the first doped region, the space region and the second region by a process such as chemical vapor deposition. Subsequently, the doped semiconductor material layer is selectively etched, and at the same time, the passivation material layer is selectively etched to obtain passivation layers located between the second doped region and the semiconductor substrate, and between the conductive semiconductor structure and the semiconductor substrate. Naturally, before the formation of the intrinsic semiconductor layer, a passivation layer may be formed only in the second region by a process such as deposition and etching.

[0207] Manufacturing method 2: A second doped region is formed in the first region. Next, a doped semiconductor material layer is integrally formed in the second doped region, the space region, and the second region. Next, the doped semiconductor material layer is selectively etched to remove portions of the doped semiconductor material layer that are in part of the second doped region and in part of the space region, thereby forming a first doped region and at least one conductive semiconductor structure with the selectively etched doped semiconductor material layer, wherein the first doped region is located in the second region, the conductivity types of the first doped region and the second doped region are opposite, the conductivity type of the first doped region and the conductive semiconductor structure are the same, only a portion of the first doped region and only a portion of the second doped region are electrically in contact with at least one conductive semiconductor structure, the conductive semiconductor structure includes an integrally continuous first conductive semiconductor portion and a second conductive semiconductor portion, the first conductive semiconductor portion is located between the first doped region and the second doped region, and the second conductive semiconductor portion is located above the portion in the second doped region opposite to the semiconductor substrate.

[0208] The specific manufacturing process of this manufacturing method 2 can be described by referring to the specific manufacturing process of manufacturing method 1 as described above. The difference between the two is that in manufacturing method 1, the conductive semiconductor structure is integrally continuous with the second doped region, whereas in manufacturing method 2, the conductive semiconductor structure is integrally continuous with the first doped region.

[0209] For the beneficial effects of the third aspect and its various implementation forms in the embodiments of this application, reference can be made to the analysis of the beneficial effects of the corresponding implementation forms in the first aspect, and thus they will not be repeatedly described here.

[0210] Also, in practice, the conductive semiconductor structure may be fabricated separately from the first doped region and the second doped region so as to be formed on the semiconductor substrate. Based on this, in the actual manufacturing process, the first doped region may be formed in the first region of the non-light-receiving surface of the semiconductor substrate, and the second doped region may be formed in the second region of the non-light-receiving surface of the semiconductor substrate by processes such as deposition and selective etching. In this case, the first doped region and the second doped region are alternately distributed at intervals. Subsequently, according to the requirements of the formation range of the conductive semiconductor structure in the actual application scenario, the conductive semiconductor structure is formed in at least a part of the space region by processes such as deposition and etching.

[0211] In the above description, the technical details such as the composition and etching of each layer are not described in detail. However, those skilled in the art should understand that layers, regions, etc. of a desired shape can be formed by various technical means. Also, those skilled in the art can design a method that is not exactly the same as the method described above to form the same structure. Also, although each embodiment has been described above, it does not mean that the means in each embodiment cannot be advantageously combined and used. 。

[0212] The embodiments of the present disclosure have been described above. However, these embodiments are merely for explanation and not for limiting the scope of the present disclosure The scope of the present disclosure is limited by the appended claims and their equivalents. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present disclosure, and all of these substitutions and modifications are considered to be included within the scope of the present disclosure.

Description of Reference Signs

[0213] 11 First doped region [[ID=2 13 Conductive Semiconductor Structures 14 Striped doped areas 15 Connection Areas 16. Physical Space Layer 17. First conductive semiconductor section 18. Second conductive semiconductor section 19 Surface passivation layer 20 Electrode structure 21. Third conductive semiconductor section.

Claims

1. The invention comprises a semiconductor substrate, a first doped region, a second doped region, and at least one conductive semiconductor structure. The first doped region and the second doped region are alternately distributed at intervals on the non-light-receiving side of the semiconductor substrate, the conductivity types of the first doped region and the second doped region are opposite, the conductivity type of the conductive semiconductor structure is opposite to the conductivity type of either the first doped region or the second doped region, at least a portion of each of the conductive semiconductor structures is located between the first doped region and the second doped region, and only a portion of the first doped region and only a portion of the second doped region are electrically in contact with at least one of the conductive semiconductor structures. A back contact battery characterized in that the width of the space region located between the first doped region and the second doped region is D1, the width of the conductive semiconductor structure in the extending direction of the space region is W, and 0.5 × D1 ≤ W ≤ 6 × D1.

2. The first doped region, the second doped region, and the conductive semiconductor structure are all formed within the semiconductor substrate, and the surfaces of the first doped region, the second doped region, and the conductive semiconductor structure opposite to the light-receiving surface of the semiconductor substrate are all flush with the surface of the corresponding non-light-receiving region of the semiconductor substrate. The back contact battery according to claim 1, characterized in that, of the first doped region and the second doped region, the contact surface between the one with the opposite conductivity type to the conductive semiconductor structure and the conductive semiconductor structure includes a side effective electrical contact surface, the height of the side effective electrical contact surface is the side effective electrical contact height Z, the side effective electrical contact height Z is equal to the minimum value of the first depth and the second depth, the first depth is the depth of the one of the first doped region and the second doped region with the opposite conductivity type to the conductive semiconductor structure, and the second depth is the depth of the conductive semiconductor structure.

3. Of the first doped region and the second doped region, the one with the opposite conductivity type to the conductive semiconductor structure, and the conductive semiconductor structure both include a doped semiconductor layer located on the non-light-receiving surface of the semiconductor substrate, and the contact surface between the one of the first doped region and the second doped region with the opposite conductivity type to the conductive semiconductor structure and the conductive semiconductor structure includes a side effective electrical contact surface, and the height of the side effective electrical contact surface is the side effective electrical contact height Z. The back contact battery according to claim 1, characterized in that the side effective electrical contact height Z is equal to the minimum of the first thickness and the second thickness, and in the direction away from the non-light-receiving surface of the semiconductor substrate in the extending direction of the side effective electrical contact surface, the first thickness is the thickness corresponding to one of the first doped region and the second doped region of the side effective electrical contact surface that has a conductivity type opposite to that of the conductive semiconductor structure, and the second thickness is the thickness corresponding to the side effective electrical contact surface of the conductive semiconductor structure.

4. When the first doped region, the second doped region, and the conductive semiconductor structure all include the doped semiconductor layer formed on the non-light-receiving surface, If, on the side of the semiconductor substrate near the non-light-receiving surface, the doped semiconductor layer included in the first doped region and the second doped region whose conductivity type is opposite to that of the conductive semiconductor structure is smaller than the doped semiconductor layer included in the conductive semiconductor structure on the side of the semiconductor substrate near the non-light-receiving surface, and a part of the side surface of the doped semiconductor layer included in the first doped region and the second doped region whose conductivity type is opposite to that of the conductive semiconductor structure is in electrical contact with the semiconductor substrate, and the other part of the side surface of the doped semiconductor layer included in the first doped region and the second doped region whose conductivity type is opposite to that of the conductive semiconductor structure is in electrical contact with the conductive semiconductor structure, then the effective electrical contact height Z of the side surface is equal to the thickness of the conductive semiconductor structure, or The back contact battery according to claim 3, characterized in that, among the first doped region and the second doped region on the side of the semiconductor substrate near the non-light-receiving surface, the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure and the doped semiconductor layer included in the conductive semiconductor structure have different arrangement heights, and when each region of the portion of the side surface of the doped semiconductor layer included in the one with the opposite conductivity type to the conductive semiconductor structure among the first doped region and the second doped region is in electrical contact with the conductive semiconductor structure, the effective electrical contact height Z of the side surface is equal to the thickness of the one with the opposite conductivity type to the conductive semiconductor structure among the first doped region and the second doped region.

5. The back contact battery according to any one of claims 2 to 4, characterized in that 0.00005 mm ≤ Z ≤ 0.002 mm.

6. In the case where, on the side of the semiconductor substrate closer to the non-light-receiving surface, the arrangement height of the doped semiconductor layer included in the one of the first and second doped regions whose conductivity type is opposite to that of the conductive semiconductor structure is smaller than the arrangement height of the doped semiconductor layer included in the other of the first and second doped regions on the side of the semiconductor substrate closer to the non-light-receiving surface, and a part of the side surface of the doped semiconductor layer included in the one of the first and second doped regions whose conductivity type is opposite to that of the conductive semiconductor structure is in electrical contact with the semiconductor substrate, and the other part of the side surface of the doped semiconductor layer included in the one of the first and second doped regions whose conductivity type is opposite to that of the conductive semiconductor structure is in electrical contact with the conductive semiconductor structure, The back contact battery according to claim 4, characterized in that, in the thickness direction of the semiconductor substrate, the difference between the surface height of the region of the non-light-receiving surface corresponding to the conductive semiconductor structure and the surface height of the region of the first doped region and the second doped region that has a conductivity type opposite to that of the conductive semiconductor structure is 0.4 μm or more and 2 μm or less.

7. The first doped region and the second doped region each include a plurality of striped doped regions, and the striped doped regions included in the first doped region and the striped doped regions included in the second doped region are distributed parallel to each other with intervals between them. The back contact battery according to claim 1, characterized in that at least a portion of the conductive semiconductor structure is located between two adjacent stripe-shaped doped regions having opposite conductivity types.

8. When the first doped region and the second doped region are distributed alternately at intervals in a comb-like manner, each of the first and second doped regions includes a plurality of striped doped regions and at least one connecting region, the striped doped regions included in the first doped region and the striped doped regions included in the second doped region are distributed alternately in parallel and at intervals, each of the connecting regions is electrically connected to a corresponding striped doped region of the same conductivity type as itself, and the direction of extension of the connecting region is different from the direction of extension of the striped doped regions. The back contact battery according to claim 1, characterized in that at least a portion of at least one of the conductive semiconductor structures is located between two adjacent stripe-shaped doped regions, each belonging to the first doped region and the second doped region, and the width direction of the conductive semiconductor structure is parallel to the direction of extension of the stripe-shaped doped regions, and / or at least a portion of at least one of the conductive semiconductor structures is located between one of the stripe-shaped doped regions included in one of the first doped region and the second doped region and an adjacent connection region included in the other of the first doped region and the second doped region, and the width direction of the conductive semiconductor structure is parallel to the distribution direction of the stripe-shaped doped regions of the opposite conductivity type.

9. If at least a portion of the conductive semiconductor structure belongs to the first doped region and the second doped region, respectively, and is located between two adjacent stripe-shaped doped regions, then in the first doped region, the width of the stripe-shaped doped region corresponding to the conductive semiconductor structure is D2, and in the second doped region, the width of the stripe-shaped doped region corresponding to the conductive semiconductor structure is D3. In the distribution direction of the stripe-shaped doped region of the opposite conductivity type, the length of the conductive semiconductor structure is D. [Math 1] The back contact battery according to claim 7 or 8, characterized in that it is the back contact battery according to claim 7 or 8.

10. When at least a portion of the conductive semiconductor structure is located between one of the stripe-shaped doped regions included in the first doped region and the second doped region and an adjacent connection region included in the other of the first doped region and the second doped region, the width of the connection region belonging to one of the first doped region and the second doped region and corresponding to the conductive semiconductor structure is W1, and the length of the stripe-shaped doped region belonging to the other of the first doped region and the second doped region and corresponding to the conductive semiconductor structure is W2. The back contact battery according to claim 8, characterized in that, in the width direction of the space region, the length of the conductive semiconductor structure is D, and D1 ≤ D ≤ D1 + W1 + W2. [Request Item 11] [Number 2] The back contact battery according to claim 10, characterized in that it is the back contact battery according to claim 10.

12. The area of ​​the orthographic projection on the non-light-receiving surface side of the portion of at least one conductive semiconductor structure located between the first doped region and the second doped region is S1, the area of ​​the non-light-receiving surface is S2, and the ratio of S1 to S2 is 8.5 × 10 －７ % or more 6.67 × 10 －１ The back contact battery according to claim 1, characterized in that it is less than or equal to %.

13. The back contact battery according to claim 1, comprising a plurality of the conductive semiconductor structures, wherein adjacent conductive semiconductor structures are arranged at intervals.

14. If the back contact battery is an integrated back contact battery, the number of conductive semiconductor structures included in the back contact battery is 30 or more and 8000 or less, or The back contact battery according to claim 13, characterized in that, when the back contact battery is a 1 / N split back contact battery, the number of conductive semiconductor structures included in the back contact battery is 30 / N or more and 8000 / N or less, where N is a positive integer of 2 or more.

15. The back contact battery according to claim 13, characterized in that the sum of the orthographic areas on the non-light-receiving surface side of the portion located between the first doped region and the second doped region of all the conductive semiconductor structures is S3, the area of ​​the non-light-receiving surface is S2, and the ratio of S3 to S2 is 0.002% or more and 20% or less.

16. The orthographic projection areas on the non-photoreceiving side of the different conductive semiconductor structures are equal, and / or The back contact battery according to claim 13, characterized in that the different conductive semiconductor structures are uniformly distributed on the non-light-receiving surface side.

17. The back contact battery according to claim 13, characterized in that the different conductive semiconductor structures are distributed in a matrix on the non-light-receiving surface side, and adjacent rows of the matrix-distributed conductive semiconductor structures are aligned or arranged in a staggered pattern.

18. The back contact battery according to claim 17, characterized in that, when adjacent rows of the conductive semiconductor structures distributed in a matrix are arranged in a staggered pattern, the displacement distance between two adjacent rows of the conductive semiconductor structures is equal to half the distance between the geometric centers of two adjacent conductive semiconductor structures within the same row.

19. The conductive semiconductor structure has the same conductivity type as the first doped region, is integrally continuous with it, or The back contact battery according to claim 1, characterized in that the conductive semiconductor structure has the same conductivity type as the second doped region and is integrally continuous.

20. The back contact battery according to claim 1, wherein at least one of the first doped region, the second doped region, and the conductive semiconductor structure includes a doped semiconductor layer located on the non-light-receiving surface of the semiconductor substrate, and the back contact battery further includes a passivation layer located between the semiconductor substrate and the doped semiconductor layer.

21. The back contact battery according to claim 20, characterized in that the doped semiconductor layer comprises at least one of a doped polycrystalline silicon layer, a doped single-crystal silicon layer, a doped amorphous silicon layer, a doped microcrystalline silicon layer, and / or the passivation layer comprises a tunnel passivation layer or an intrinsic amorphous silicon layer.

22. A solar module characterized by including a back contact battery as described in any one of claims 1 to 21.

23. The steps include providing a semiconductor substrate and A step of forming a first doped region and a second doped region on the non-light-receiving side of the semiconductor substrate, wherein the first doped region and the second doped region are alternately distributed at intervals on the non-light-receiving side of the semiconductor substrate, and the conductivity types of the first doped region and the second doped region are opposite. A method for manufacturing a back contact battery, comprising the step of forming at least one conductive semiconductor structure on the non-light-receiving side of the semiconductor substrate, wherein the conductivity type of the conductive semiconductor structure is opposite to the conductivity type of one of the first doped region and the second doped region, at least a portion of each of the conductive semiconductor structures is located between the first doped region and the second doped region, only a portion of the first doped region and only a portion of the second doped region are electrically in contact with at least one of the conductive semiconductor structures, the width of the space region located between the first doped region and the second doped region is D1, the width of the conductive semiconductor structure in the direction extending the space region is W, and 0.5 × D1 ≤ W ≤ 6 × D1.

24. The non-light-receiving surface of the semiconductor substrate has a first region and a second region that are alternately distributed at intervals, and a space region located between the first region and the adjacent second region. The steps of forming the first doped region and the second doped region on the non-light-receiving side of the semiconductor substrate, and forming at least one conductive semiconductor structure on the non-light-receiving side of the semiconductor substrate, The steps of forming the first doped region in the first region, The steps include integrally forming a doped semiconductor material layer in the first doped region, the space region, and the second region, The steps include selectively etching the doped semiconductor material layer to remove a portion of the doped semiconductor material layer corresponding to a part of the first doped region and a portion of the space region, The method for manufacturing a back contact battery according to claim 23, comprising the step of forming a second doped region located in the second region and the conductive semiconductor structure with the selectively etched doped semiconductor material layer.

25. The non-light-receiving surface of the semiconductor substrate has a first region and a second region that are alternately distributed at intervals, and a space region located between the first region and the adjacent second region. The steps of forming the first doped region and the second doped region on the non-light-receiving side of the semiconductor substrate, and forming at least one conductive semiconductor structure on the non-light-receiving side of the semiconductor substrate, The steps include forming the second doped region in the first region, The steps include forming a doped semiconductor material layer integrally in the second doped region, the space region, and the second region, The steps include selectively etching the doped semiconductor material layer to remove a portion of the doped semiconductor material layer corresponding to a part of the second doped region and a portion of the space region, The method for manufacturing a back contact battery according to claim 23, comprising the step of forming the first doped region located in the second region and the conductive semiconductor structure with the selectively etched doped semiconductor material layer.

Images