Solar cell and manufacturing method thereof

Abstract

The invention discloses a solar cell and a manufacturing method thereof, relates to the field of photovoltaic technology, and aims to reduce the damage degree of a first semiconductor layer and / or a semiconductor substrate positioned in a first conductive contact area and improve the yield of the solar cell in the process of manufacturing a first connecting layer for realizing electric connection. The solar cell includes a semiconductor substrate, a first semiconductor layer, a first connection layer, and a plurality of conductive electrodes. The multiple conductive electrodes are arranged on the side, away from the first semiconductor layer, of the first connecting layer. The first connection layer includes a first passivation layer disposed in the first passivation isolation region and the plurality of first conductive contact regions, and a first connection electrode disposed in the first conductive contact regions. The first passivation layer is hollowed out in the first conductive contact area, one end, in the thickness direction of the first passivation layer, of the first connection electrode is electrically connected with the first semiconductor layer, and the other end of the first connection electrode is exposed out of the first passivation layer and electrically connected with the conductive electrode.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a solar cell and a manufacturing method thereof. Background Art

[0002] A solar cell is a device that can convert sunlight into electrical energy. Specifically, when a solar cell is in operation, sunlight shines on the semiconductor pn junction of the solar cell, forming new hole-electron pairs. Under the action of the built-in electric field of the pn junction, the photogenerated holes flow to the p region, and the photogenerated electrons flow to the n region. After connecting to the external circuit through the positive and negative electrodes of the battery, current can be generated.

[0003] However, the existing manufacturing method of solar cells is likely to cause damage to the semiconductor layer and / or semiconductor substrate located below the positive and negative electrodes when manufacturing the positive and negative electrodes, thereby affecting the working performance of the solar cell. Summary of the invention

[0004] The object of the present invention is to provide a solar cell and a method for manufacturing the same, which is used to reduce the degree of damage to the first semiconductor layer and / or the semiconductor substrate located in the first conductive contact area during the process of manufacturing the first connection layer, thereby improving the yield of the solar cell. In addition, in addition to the first connection electrode, a first passivation layer is also provided in the first conductive contact area, which can reduce the recombination of the first conductive contact area.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a solar cell, which comprises: a semiconductor substrate, a first semiconductor layer, a first connection layer and a plurality of conductive electrodes. The first semiconductor layer is arranged on the semiconductor substrate. The first connection layer is arranged on the side of the first semiconductor layer away from the semiconductor substrate. A plurality of conductive electrodes are arranged on the side of the first connection layer away from the first semiconductor layer. In a thickness direction perpendicular to the first connection layer, the first connection layer has a first passivation isolation region and a first conductive contact region. Among them, the first connection layer comprises a first passivation layer arranged in the first passivation isolation region and the first conductive contact region, and a first connection electrode arranged in the first conductive contact region. The conductive electrode is electrically connected to the first connection electrode of at least one first conductive contact region. The first passivation layer is hollowed out in the first conductive contact region, one end of the first connection electrode along the thickness direction of the first passivation layer is electrically connected to the first semiconductor layer, and the other end of the first connection electrode is exposed in the first passivation layer and is electrically connected to the conductive electrode.

[0006] In the case of adopting the above technical solution, when the solar cell is in working state, the first semiconductor layer can realize the shunting and collection of carriers. In addition, the first connection layer arranged on the side of the first semiconductor layer away from the semiconductor substrate is provided with a first conductive contact area, and the first passivation layer located in the first conductive contact area is hollowed out, so that one end of the first connection electrode arranged in the first conductive contact area is electrically connected to the first semiconductor layer, and the other end is exposed in the first passivation layer and electrically connected to the conductive electrode, so as to lead out the carriers collected by the first semiconductor layer, which is conducive to forming a photocurrent and reducing the difficulty of connecting the battery to the external circuit. It is worth noting that for any conductive electrode, it is not only arranged above at least one first conductive contact area, but also arranged above part of the first passivation isolation area. In addition, the first passivation layer in the first connection layer is not only arranged in the first passivation isolation area, but also arranged in the first conductive contact area for realizing conductive contact. At this time, the first passivation layer has a large passivation contact area on the first semiconductor layer, so that the first semiconductor layer has a higher passivation effect, and the carrier recombination rate on the side of the first semiconductor layer away from the semiconductor substrate is reduced. At the same time, compared with the prior art in which a high-temperature laser is used to directly heat the semiconductor substrate (or the semiconductor substrate and the first semiconductor layer) so as to generate a large thermal stress between the semiconductor substrate and the passivation layer due to the temperature gradient, causing the passivation layer to explode in the laser irradiation area corresponding to the laser (i.e., the portion of the passivation layer located in the first conductive contact area is completely removed by the explosion), the solar cell provided by the present invention also retains a portion of the first passivation layer located in the first conductive contact area. At this time, the requirement for the etching temperature of the patterning process can be reduced, so as to reduce the degree of thermal damage to the portion of the semiconductor substrate (or the semiconductor substrate and the first semiconductor layer) located below the first passivation layer in the first conductive contact area by the patterning process, thereby improving the yield of the solar cell and facilitating the manufactured solar cell to have good working performance.

[0007] As a possible implementation scheme, the first passivation layer includes a nitrogen-containing passivation layer. In this case, the nitrogen-containing passivation layer has good adhesion and is easy to process and manufacture.

[0008] As a possible implementation scheme, the material of the first passivation layer includes at least one of silicon nitride and silicon oxynitride. In this case, silicon nitride and silicon oxynitride can not only play the role of insulation and passivation anti-reflection, but also have a good protective effect, and can well protect the first semiconductor layer located thereunder, and are insulating passivation materials with relatively comprehensive performance. Therefore, when the material of the first passivation layer includes silicon nitride and / or silicon oxynitride, it is beneficial to improve the working performance of the solar cell.

[0009] As a possible implementation solution, a nitrogen content of the first passivation layer in the first conductive contact region is smaller than a nitrogen content of the first passivation layer in the first passivation isolation region.

[0010] In the case of adopting the above technical solution, in the actual manufacturing process, the portion of the first passivation layer located in the first conductive contact area can be heat-treated by laser irradiation or the like, and the first passivation layer located in the first conductive contact area is partially removed after being heated. The specific removal method can be, for example, thermal gasification, thermal film explosion, or heating to volatilize the nitrogen element therein in the form of nitrogen gas, so that in the first passivation layer after the heat treatment, the nitrogen content of the portion located in the first conductive contact area is reduced, and a hole or the like structure may be formed in the first passivation layer, so that the first passivation layer is hollowed out in the first conductive contact area, which is beneficial to the manufacture of the first connection electrode. It can be seen that compared with the prior art of completely removing the portion of the passivation layer located in the first conductive contact area by high-temperature laser film blasting, in the solar cell provided by the present invention, only the nitrogen content of the first passivation layer in the first conductive contact area is set to be less than the nitrogen content of the first passivation layer in the first passivation isolation area, so as to reduce the degree of thermal damage caused by the patterning treatment to the portion of the semiconductor substrate (or to the semiconductor substrate and the first semiconductor layer) located below the first passivation layer in the first conductive contact area, thereby improving the yield of the solar cell and facilitating the manufactured solar cell to have good working performance.

[0011] As a possible implementation scheme, the portion of the first passivation layer located in the first conductive contact region has a plurality of holes penetrating the first passivation layer. In this case, the first connection electrode can penetrate the first passivation layer through the holes in the first passivation layer disposed in the first conductive contact region, thereby leading out the carriers collected by the first semiconductor layer and reducing the carrier recombination rate.

[0012] As a possible implementation scheme, in the first passivation layer, the area of ​​the hollow region and the area of ​​the first passivation layer account for a ratio greater than or equal to 0.1% and less than or equal to 80%. In this case, it can be prevented that the contact area between the first connection electrode and the first semiconductor layer is small due to the small area ratio of the hollow region, thereby reducing the contact resistance between the first connection electrode and the first semiconductor layer. It can also be prevented that the passivation contact area between the first passivation layer and the first semiconductor layer is small due to the large area ratio of the hollow region, which is beneficial for the first passivation layer to have a higher passivation effect on the first semiconductor layer, and reduce the carrier recombination rate of the first semiconductor layer away from the semiconductor substrate.

[0013] As a possible implementation solution, the maximum pore size of at least one hole is greater than or equal to 5 nm and less than or equal to 40 μm.

[0014] In the case of adopting the above technical solution, the formation of the hole is due to the heat treatment of the first passivation layer located in the first conductive contact area, so that the hole is formed by heat gasification, heat explosion or volatilization of heated gas. Based on this, it can be understood that the higher the temperature of the heat treatment, the larger the aperture and / or number of the holes formed in the first passivation layer. On the contrary, the lower the temperature of the heat treatment, the smaller the aperture and / or number of the holes formed in the first passivation layer. In this case, the maximum aperture of at least one hole is within the above range, which is conducive to preventing the first connection electrode from being electrically connected to the first semiconductor layer through the hole due to the maximum aperture of the hole being too small, reducing the contact resistance between the first connection electrode and the first semiconductor layer, and further reducing the carrier recombination rate of the first semiconductor layer away from the semiconductor substrate, which is conducive to improving the conversion efficiency of the solar cell. In addition, it can also prevent the heat treatment temperature of the first passivation layer from being too high due to the excessive size of the hole, further reduce the degree of thermal damage to the semiconductor substrate after patterning, improve the yield of the manufactured solar cell, and help the solar cell have good working performance.

[0015] As a possible implementation scheme, in at least one first conductive contact region, the ratio of the total area of ​​the holes in the first conductive contact region to the area of ​​the first conductive contact region is greater than or equal to 1% and less than or equal to 20%. The application principle of the beneficial effect in this case can refer to the application principle of the beneficial effect of the maximum pore size of at least one hole being greater than or equal to 5nm and less than or equal to 40μm described above, and will not be repeated here.

[0016] As a possible implementation scheme, in at least one hole, a size of a hole opening on a side away from the first semiconductor layer is smaller than a size of a hole bottom on a side close to the first semiconductor layer.

[0017] In the case of adopting the above technical solution, the size of the first connection electrode set at the bottom of the hole is relatively large, which is conducive to a larger contact area between the first connection electrode and the first semiconductor layer, reducing the contact resistance between the two. The hole opening size on the side of the hole away from the first semiconductor layer is relatively small, which is conducive to enhancing the adhesion between the first connection electrode and the first passivation layer located in the first conductive contact area, reducing the risk of the first connection electrode falling off from the first passivation layer, enhancing the contact performance and contact strength between the first connection electrode and the first semiconductor layer, and improving the yield of the solar cell.

[0018] As a possible implementation scheme, at least one hole is cylindrical, bowl-like or gourd-like. In this case, the morphology of the hole has a variety of examples, which is conducive to improving the applicability of the solar cell provided by the present invention in different practical application environments. In addition, it is also conducive to reducing the difficulty of the manufacturing process of forming the hole in the first passivation layer located in the first conductive contact area.

[0019] As a possible implementation scheme, the first passivation layer has a texture structure on a side facing away from the first semiconductor layer. In the first conductive contact region, holes are distributed at least at the ridges of the texture structure.

[0020] In the case of adopting the above technical solution, since the first passivation layer is formed on the side of the first semiconductor layer away from the semiconductor substrate by chemical vapor deposition and other processes, the surface morphology of the first passivation layer can often reflect the surface morphology of the first semiconductor layer away from the semiconductor substrate. It can be understood that compared with the interior of the texture structure, due to the undulating morphology at the ridges of the texture structure, the specific surface area at the ridges is larger, and the specific surface area of ​​the corresponding first semiconductor layer at the ridges of the texture structure corresponding to the first passivation layer is also relatively large. Based on this, when the holes are distributed at least at the ridges of the texture structure, it is beneficial to increase the contact area between the first connecting electrode and the first semiconductor layer through the holes, and further reduce the contact resistance between the two. In addition, the deposited film thickness of the first passivation layer is inversely proportional to the specific surface area of ​​the surface on which it is deposited. Therefore, the deposited film thickness of the first passivation layer at the ridges of the texture structure with a relatively large specific surface area is relatively small. Moreover, when the laser acts on the first conductive contact area, since the structure at the ridges is more prominent, the laser energy is concentrated on the ridges, which is conducive to forming a penetrating hole in the portion of the first passivation layer corresponding to the ridges, thereby reducing the process difficulty of hollowing out the first passivation layer located in the first conductive contact area, and improving the yield and working performance of solar cells.

[0021] As a possible implementation, the holes are also distributed in the texture structure. In the first conductive contact area, the distribution density of the holes at the ridges of the texture structure is greater than the distribution density of the holes in the texture structure.

[0022] When the above technical solution is adopted, the holes are distributed not only at the ridges of the texture structure, but also in the texture structure, which is conducive to increasing the number of holes in the first passivation layer located in the first conductive contact area, thereby increasing the contact area between the first connection electrode and the first semiconductor layer, and improving the contact performance between the first connection electrode and the first semiconductor layer. In addition, in the first conductive contact area, the distribution density of the holes at the ridges of the texture structure is greater, which is conducive to further increasing the contact area between the first connection electrode and the first semiconductor layer through the holes, while further reducing the process difficulty of hollowing out the first passivation layer located in the first conductive contact area, thereby improving the yield and working performance of the solar cell.

[0023] As a possible implementation solution, there is no glass body in the first conductive contact area of ​​the first connection layer, so as to prevent the glass body from affecting the conductivity of the first conductive contact area.

[0024] As a possible implementation scheme, the first passivation layer is randomly distributed in the first conductive contact area. In this case, the first passivation layer located in the first conductive contact area is irregularly distributed, which provides another example for the solar cell provided by the present invention, and improves the applicability of the solar cell provided by the present invention in different application scenarios.

[0025] As a possible implementation scheme, when the first passivation layer is randomly distributed in the first conductive contact area, in at least one first conductive contact area, the ratio of the total area of ​​the hollow area of ​​the first conductive contact area to the area of ​​the first conductive contact area is greater than or equal to 1% and less than or equal to 95%. The application principle of the beneficial effect in this case can refer to the application principle of the beneficial effect that the area of ​​the hollow area in the first passivation layer accounts for greater than or equal to 0.1% and less than or equal to 80% of the area of ​​the first passivation layer as described above, and will not be repeated here.

[0026] As a possible implementation scheme, the thickness of the first passivation layer in the first conductive contact region is less than the thickness of the first passivation layer in the first passivation isolation region. In this case, it is helpful to reduce the difficulty of hollowing out the first passivation layer in the first conductive contact region and / or the heat treatment temperature, further reduce the degree of damage to the first semiconductor layer and the semiconductor substrate after patterning, and improve the yield and working performance of the solar cell.

[0027] As a possible implementation solution, the thickness of the first passivation layer located in the first conductive contact region is less than or equal to 350 nm.

[0028] When adopting the above technical solution, the thickness of the first passivation layer in the first conductive contact area is within the above range, which is conducive to preventing the difficulty of hollowing out the first passivation layer in the first conductive contact area and / or high heat treatment temperature due to the large thickness of the first passivation layer in the first conductive contact area, further reducing the degree of damage to the first semiconductor layer and the semiconductor substrate after patterning treatment, and improving the yield and working performance of solar cells.

[0029] As a possible implementation solution, the material of the first connection electrode includes one or more of gold, silver, copper, aluminum, nickel, chromium, titanium and tin.

[0030] When the above technical solution is adopted, the material of the first connection electrode has multiple optional types. And the manufacturing processes of the first connection electrode corresponding to different material types may be different. Therefore, when the material of the first connection electrode includes the above types, multiple manufacturing processes can be used to form the first connection electrode, which is conducive to improving the applicability of the solar cell provided by the present invention in different application scenarios.

[0031] As a possible implementation scheme, the thickness of the first passivation layer is greater than or equal to 2nm and less than or equal to 350nm. The application principle of the beneficial effect in this case is similar to the application principle of the beneficial effect of the first passivation layer being located in the first conductive contact area with a thickness less than or equal to 350nm as described above, and will not be repeated here.

[0032] As a possible implementation, the refractive index of the first passivation layer is greater than or equal to 1.5 and less than or equal to 3. In this case, the refractive index of the first passivation layer is set within a reasonable range, which is conducive to reducing the reflectivity of the first passivation layer to incident light and improving the utilization rate of light by the solar cell.

[0033] As a possible implementation, the ratio between the width of the conductive electrode and the width of the first conductive contact region is greater than or equal to 0.6 and less than or equal to 2. In this case, the width range of the first conductive contact region is relatively large, which is conducive to improving the applicability of the solar cell provided by the present invention in different application scenarios.

[0034] As a possible implementation scheme, the first passivation layer located in the first passivation isolation region includes an amorphous state, and the first passivation layer located in at least a portion of the first conductive contact region includes a crystalline state.

[0035] In the case of adopting the above technical solution, the first passivation layer itself is amorphous, and the portion thereof located in at least part of the first conductive contact area is crystalline after being processed; for example, the first passivation layer located in at least part of the first conductive contact area is crystalline after being irradiated with laser. The structural stability of the first passivation layer located in at least part of the first conductive contact area can be enhanced, thereby improving the reliability of the solar cell and extending its service life. In addition, the first passivation layer located in at least part of the first conductive contact area is crystalline, which can also improve the conductivity of the first passivation layer located in at least part of the first conductive contact area, which is beneficial to reduce the contact resistance between the surface of the first passivation layer located in at least part of the first conductive contact area and the first connecting electrode and / or the conductive electrode, thereby reducing current loss.

[0036] As a possible implementation scheme, the surface of the first passivation layer located in at least part of the first conductive contact region includes an oxide layer. In this case, the performance of the oxide is more stable, and the surface of the first passivation layer located in at least part of the first conductive contact region is formed with an oxide layer, which can further improve the stability of the first passivation layer and further improve the reliability of the solar cell. In addition, the oxide layer of the insulating material (such as silicon oxide, silicon oxynitride, etc.) may have a passivation effect, which is conducive to further reducing the carrier recombination rate on the side of the first semiconductor layer away from the semiconductor substrate.

[0037] As a possible implementation scheme, the solar cell further includes a surface passivation layer disposed between the first semiconductor layer and the first connection layer. The first connection electrode penetrates the surface passivation layer and is electrically connected to the first semiconductor layer.

[0038] When the above technical solution is adopted, the surface passivation layer can passivate the side of the first semiconductor layer away from the semiconductor substrate, thereby further reducing the carrier recombination rate on the side of the first semiconductor layer away from the semiconductor substrate.

[0039] As a possible implementation scheme, the solar cell also includes a second semiconductor layer of opposite conductivity type to the first semiconductor layer. The first semiconductor layer and the second semiconductor layer are arranged on the same side of the semiconductor substrate, and at least a part of the first semiconductor layer and at least a part of the second semiconductor layer are physically insulated; the first connection layer also has a second conductive contact area; the first passivation layer is also arranged in the second conductive contact area, and the nitrogen content of the first passivation layer in the second conductive contact area is less than the nitrogen content of the first passivation layer in the first passivation isolation area; the first passivation layer is hollowed out in the second conductive contact area; the first connection layer also includes a second connection electrode arranged in the second conductive contact area; one end of the second connection electrode along the thickness direction of the first passivation layer is electrically connected to the second semiconductor layer, and the other end of the second connection electrode is exposed in the first passivation layer. Alternatively, the first semiconductor layer and the second semiconductor layer are arranged on opposite sides of the semiconductor substrate, respectively. The solar cell also includes a second connection layer; along a thickness direction perpendicular to the second connection layer, the second connection layer has a second passivation isolation region and a second conductive contact region; the second connection layer includes a second passivation layer arranged in the second passivation isolation region and the second conductive contact region, and a second connection electrode arranged in the second conductive contact region; the nitrogen content of the second passivation layer in the second conductive contact region is less than the nitrogen content of the second passivation layer in the second passivation isolation region; the second passivation layer is hollowed out in the second conductive contact region, one end of the second connection electrode along the thickness direction of the second passivation layer is electrically connected to the second semiconductor layer, and the other end of the second connection electrode is exposed in the second passivation layer.

[0040] When the above technical solution is adopted, the first passivation layer (or the second passivation layer) can have a larger passivation contact area on the second semiconductor layer, so that it has a higher passivation effect on the second semiconductor layer and reduces the carrier recombination rate on the side of the second semiconductor layer away from the semiconductor substrate.

[0041] As a possible implementation solution, the area of ​​the first conductive contact region is different from the area of ​​the second conductive contact region.

[0042] As a possible implementation solution, the total area of ​​all the first conductive contact regions in the first connection layer is different from the total area of ​​all the second conductive contact regions in the first connection layer.

[0043] As a possible implementation solution, the total area of ​​all the first conductive contact regions in the first connection layer is different from the total area of ​​all the second conductive contact regions in the second connection layer.

[0044] As a possible implementation solution, the area of ​​the hollow region of the first conductive contact region is different from the area of ​​the hollow region of the second conductive contact region.

[0045] As a possible implementation solution, the total area of ​​the hollow regions of all the first conductive contact regions in the first connection layer is different from the total area of ​​the hollow regions of all the second conductive contact regions in the first connection layer.

[0046] As a possible implementation solution, the total area of ​​the hollow regions of all the first conductive contact regions in the first connection layer is different from the total area of ​​the hollow regions of all the second conductive contact regions in the second connection layer.

[0047] As a possible implementation scheme, when the first semiconductor layer and the second semiconductor layer are arranged on the same side of the semiconductor substrate, and the first passivation layer includes a nitrogen-containing passivation layer, the nitrogen content of the first passivation layer in the second conductive contact region is less than the nitrogen content of the first passivation layer in the first passivation isolation region; or, when the first semiconductor layer and the second semiconductor layer are arranged on opposite sides of the semiconductor substrate, and the second passivation layer includes a nitrogen-containing passivation layer, the nitrogen content of the second passivation layer in the second conductive contact region is less than the nitrogen content of the second passivation layer in the second passivation isolation region. In this case, it is beneficial to reduce the degree of thermal damage to the semiconductor substrate (or to the semiconductor substrate and the second semiconductor layer) located below the second conductive contact region by patterning, improve the yield of the solar cell, and help the manufactured solar cell have good working performance.

[0048] In a second aspect, the present invention provides a method for manufacturing a solar cell, the method for manufacturing a solar cell comprising: first, providing a semiconductor substrate. Next, forming a first semiconductor layer on the semiconductor substrate. Next, forming a first connection layer on the side of the first semiconductor layer away from the semiconductor substrate. Along the thickness direction perpendicular to the first connection layer, the first connection layer has a first passivation isolation region and a first conductive contact region, wherein the first connection layer includes a first passivation layer arranged in the first passivation isolation region and the first conductive contact region, and a first connection electrode arranged in the first conductive contact region. The first passivation layer is hollowed out in the first conductive contact region, one end of the first connection electrode along the thickness direction of the first passivation layer is electrically connected to the first semiconductor layer, and the other end of the first connection electrode is exposed in the first passivation layer. Next, a plurality of conductive electrodes are formed on the side of the first connection layer away from the first semiconductor layer. The conductive electrode is electrically connected to the first connection electrode of at least one first conductive contact region.

[0049] As a possible implementation scheme, forming a first connection layer on a side of the first semiconductor layer away from the semiconductor substrate includes: forming a first passivation layer on a side of the first semiconductor layer away from the semiconductor substrate. Next, using a laser to irradiate a portion of the first passivation layer located in the first conductive contact area so that a portion of the first passivation layer located in the first conductive contact area is removed. Next, forming a first connection electrode in the first conductive contact area.

[0050] When adopting the above technical scheme, compared with the prior art in which the semiconductor substrate (or the semiconductor substrate and the first semiconductor layer) is directly heated by a high-temperature laser, thereby completely removing the first passivation layer located in the first conductive contact area by generating a huge thermal stress between the semiconductor substrate and the first passivation layer due to the temperature gradient, the manufacturing method provided by the present invention only removes part of the first passivation layer located in the first conductive contact area by the first laser, thereby reducing the degree of thermal damage caused by the patterning treatment to the portion of the semiconductor substrate (or the semiconductor substrate and the first semiconductor layer) located below the first passivation layer in the laser irradiation area, thereby improving the yield of the solar cell and facilitating the manufactured solar cell to have good working performance.

[0051] As a possible implementation scheme, after using laser to irradiate the portion of the first passivation layer located in the first conductive contact area and before forming the first connecting electrode in the first conductive contact area, the manufacturing method of the solar cell also includes: using a corrosive liquid to corrode the portion of the first passivation layer located in the first conductive contact area.

[0052] When the above technical solution is adopted, after the first passivation layer located in the first conductive contact area is irradiated by laser, the portion of the first passivation layer located in the first conductive contact area is corroded by a corrosive liquid, which is beneficial to further increase the area of ​​the hollow area of ​​the first passivation layer located in the first conductive contact area, and / or, it is beneficial to make the concave structures such as blind holes that originally did not penetrate the first passivation layer in the first conductive contact area form hollow structures such as through holes that penetrate the first passivation layer, which is beneficial to make the first connecting electrode and the first semiconductor layer have a larger contact area.

[0053] As a possible implementation scheme, forming a first passivation layer on a side of the first semiconductor layer away from the semiconductor substrate includes: sequentially forming a stacked surface passivation layer and a first passivation layer on a side of the first semiconductor layer away from the semiconductor substrate. Furthermore, after irradiating a portion of the first passivation layer located in the first conductive contact region with a laser, before forming a first connection electrode in the first conductive contact region, the method for manufacturing a solar cell further includes: selectively etching the surface passivation layer under the masking action of the first passivation layer.

[0054] As a possible implementation scheme, after providing a semiconductor substrate, the method for manufacturing a solar cell further includes: forming a second semiconductor layer of opposite conductivity type to the first semiconductor layer on the semiconductor substrate. The first semiconductor layer and the second semiconductor layer are arranged on the same side of the semiconductor substrate, and at least a portion of the first semiconductor layer is physically insulated from at least a portion of the second semiconductor layer; or the first semiconductor layer and the second semiconductor layer are respectively arranged on opposite sides of the semiconductor substrate.

[0055] The beneficial effects of the second aspect of the present invention and its various implementations can be analyzed by referring to the beneficial effects of the first aspect and its various implementations, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0057] Figure 1 A schematic diagram of the electrode structure in a solar cell provided for related technologies;

[0058] Figure 2 A schematic longitudinal cross-sectional view of a first structure of a solar cell provided by an embodiment of the present invention;

[0059] Figure 3 A schematic longitudinal cross-sectional view of a second structure of a solar cell provided by an embodiment of the present invention;

[0060] Figure 4 A SEM image of a part of the structure of the solar cell provided by an embodiment of the present invention on the side of the first connection layer away from the semiconductor substrate;

[0061] Figure 5 A schematic longitudinal cross-sectional view of a third structure of a solar cell provided by an embodiment of the present invention;

[0062] Figure 6 A schematic longitudinal cross-sectional view of a fourth structure of a solar cell provided by an embodiment of the present invention;

[0063] Figure 7 A schematic longitudinal cross-sectional view of a fifth structure of a solar cell provided by an embodiment of the present invention;

[0064] Figure 8 A schematic longitudinal cross-sectional view of a sixth structure of a solar cell provided by an embodiment of the present invention;

[0065] Fig. 9 A longitudinal cross-sectional schematic diagram of a seventh structure of a solar cell provided by an embodiment of the present invention;

[0066] Fig.10 A schematic longitudinal cross-sectional view of an eighth structure of a solar cell provided by an embodiment of the present invention;

[0067] Fig.11 A schematic longitudinal cross-sectional view of a ninth structure of a solar cell provided by an embodiment of the present invention;

[0068] Fig.12 A schematic longitudinal cross-sectional view of a tenth structure of a solar cell provided by an embodiment of the present invention;

[0069] Fig.13 SEM image of a part of the structure of the solar cell provided by an embodiment of the present invention on the side of the first passivation layer away from the semiconductor substrate Figure 1 ;

[0070] Fig.14 SEM image of a part of the structure of the solar cell provided by an embodiment of the present invention on the side of the first passivation layer away from the semiconductor substrate Figure 2 ;

[0071] Fig.15 A longitudinal cross-sectional SEM image of the structure of the solar cell provided by an embodiment of the present invention at the first passivation layer;

[0072] Fig.16 SEM image of a part of the structure of the solar cell provided by an embodiment of the present invention on the side of the first passivation layer away from the semiconductor substrate Figure 3 ;

[0073] Fig.17 A schematic longitudinal cross-sectional view of an eleventh structure of a solar cell provided by an embodiment of the present invention;

[0074] Fig.18 A schematic longitudinal cross-sectional view of a twelfth structure of a solar cell provided by an embodiment of the present invention;

[0075] Fig.19 A schematic longitudinal cross-sectional view of a twelfth structure of a solar cell provided by an embodiment of the present invention;

[0076] Fig. 20 A schematic longitudinal cross-sectional view of a thirteenth structure of a solar cell provided by an embodiment of the present invention;

[0077] Fig.21 A schematic longitudinal cross-sectional view of a fourteenth structure of a solar cell provided by an embodiment of the present invention;

[0078] Fig. 22 A schematic longitudinal cross-sectional view of a fifteenth structure of a solar cell provided by an embodiment of the present invention;

[0079] Fig.23A schematic longitudinal cross-sectional view of a sixteenth structure of a solar cell provided by an embodiment of the present invention;

[0080] Fig.24 A schematic longitudinal cross-sectional view of a seventeenth structure of a solar cell provided by an embodiment of the present invention;

[0081] Fig.25 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 1 ;

[0082] Fig.26 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 2 ;

[0083] Fig. 27 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 3 ;

[0084] Fig.28 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 4 ;

[0085] Fig.29 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 5 ;

[0086] Fig.30 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 6 ;

[0087] Fig.31 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 7 ;

[0088] Fig.32 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 8 ;

[0089] Fig.33 Schematic diagram of the results of the solar cell provided in the embodiment of the present invention during the manufacturing process Figure 9 .

[0090] Figure numerals: 11 is a semiconductor substrate, 12 is a first semiconductor layer, 13 is a first connecting layer, 14 is a first passivation isolation region, 15 is a first conductive contact region, 16 is a first passivation layer, 17 is a first connecting electrode, 18 is a hole, 19 is a texture structure, 20 is a conductive electrode, 21 is a surface passivation layer, 22 is a second semiconductor layer, 23 is a second conductive contact region, 24 is a second connecting electrode, 25 is a second connecting layer, 26 is a second passivation layer, 27 is a second passivation isolation region, 28 is a first interface passivation layer, 29 is a second interface passivation layer, 30 is an insulating layer, and 31 is a conductive window. DETAILED DESCRIPTION

[0091] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0092] Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for a clearer expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0093] In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. In addition, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "under" the other layer / element. In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0094] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0095] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] In the existing manufacturing method of solar cells, a conductive window is usually opened in a passivation layer arranged on a semiconductor layer before forming an electrode by photolithography, chemical etching, laser etching and the like. Among them, photolithography patterning is to coat a layer of photoresist on the passivation layer of the battery as a mask, and light is irradiated on the photoresist to cause a chemical reaction in the photoresist in the exposure area, and the pattern is transferred to the photoresist, and further combined with etching processes such as wet etching to transfer the pattern to the surface of the passivation layer. The above-mentioned photolithography patterning requires the addition of a layer of mask manufacturing process, and the process is relatively complicated. In addition, the cost of photoresist is also relatively high. At the same time, the photoresist component is organic matter, and the removed photoresist produces more pollutants, resulting in a decrease in the yield of the solar cell. The above-mentioned chemical etching method is to coat a chemical reagent in the patterned area, and after reacting under certain conditions, the passivation material is removed to achieve patterning, and its process is also relatively complicated.

[0097] For the above-mentioned laser etching, although its process is simple, it still needs to go through a wet etching process to remove the surface oxide after laser etching, resulting in a low increase in manufacturing efficiency. In addition, when a picosecond laser is used for laser etching, the temperature of the etching laser is relatively high, and the laser etching process is to heat the semiconductor substrate with an extremely short pulse wave, thereby generating a large temperature gradient between the semiconductor substrate and the mask layer, and then generating a large stress, causing the mask layer to explode and be removed under the action of thermal stress, or using a laser to heat a partial area of ​​the mask layer to remove it. However, both of these laser methods of removing the mask layer require a large laser energy density, which will inevitably damage the semiconductor substrate and the semiconductor layer in the edge area, affecting the working performance of the solar cell. It can be seen that when the existing manufacturing method is used to manufacture the positive and negative electrodes, it is easy to cause damage to the semiconductor layer and / or the semiconductor substrate located below the positive and negative electrodes, affecting the working performance of the solar cell.

[0098] And, if Figure 1As shown in the figure, a connection electrode for collecting carriers is provided in each conductive window 31, and each conductive window 31 corresponds to a single conductive contact area. Because the conductive window 31 completely penetrates the mask layer, and the mask layer in the conductive window is completely removed by the above process, the passivation effect at the conductive window 31 is poor, and the carrier recombination rate is high, which is not conducive to improving the conversion efficiency of solar energy.

[0099] In order to solve the above technical problems, in a first aspect, an embodiment of the present invention provides a solar cell. Figure 2 As shown, the solar cell provided by the embodiment of the present invention can be a double-sided contact cell, that is, one of the positive electrode and the negative electrode of the cell is arranged on the front side of the cell, and the other is arranged on the back side of the cell. Figure 3 As shown, the solar cell provided by the embodiment of the present invention can also be a back-contact cell, that is, the positive electrode and the negative electrode of the cell are both arranged on the back of the cell.

[0100] Specifically, if Figures 2 to 4 As shown, the solar cell provided by the embodiment of the present invention includes: a semiconductor substrate 11, a first semiconductor layer 12, a first connection layer 13 and a plurality of conductive electrodes 20. The first semiconductor layer 12 is disposed on the semiconductor substrate 11. The first connection layer 13 is disposed on a side of the first semiconductor layer 12 away from the semiconductor substrate 11. A plurality of conductive electrodes 20 are disposed on a side of the first connection layer 13 away from the first semiconductor layer 12. In a thickness direction perpendicular to the first connection layer 13, the first connection layer 13 has a first passivation isolation region 14 and a first conductive contact region 15. The first connection layer 13 includes a first passivation layer 16 disposed in the first passivation isolation region 14 and the first conductive contact region 15, and a first connection electrode 17 disposed in the first conductive contact region 15. The conductive electrode 20 is electrically connected to the first connection electrode 17 of at least one first conductive contact region 15. The first passivation layer 16 is hollowed out in the first conductive contact area 15 , and the first connection electrode 17 is arranged in the hollow area of ​​the first passivation layer 16 . One end of the first connection electrode 17 along the thickness direction of the first passivation layer 16 is electrically connected to the first semiconductor layer 12 , and the other end of the first connection electrode 17 is exposed in the first passivation layer 16 and electrically connected to the conductive electrode 20 .

[0101] Here, the conductive electrode 20 may be electrically connected to the first connection electrode 17 of a first conductive contact region 15, in which case the first conductive contact region 15 is continuously arranged along the extension direction of the conductive electrode 20; or the conductive electrode 20 may be electrically connected to the first connection electrodes 17 of multiple first conductive contact regions 15, in which case multiple first conductive contact regions 15 are arranged at intervals along the extension direction of the conductive electrode 20, and adjacent first conductive contact regions 15 are separated by the first passivation layer 16.

[0102] In addition, the conductive electrode 20 is electrically connected to the first connection electrode 17 of at least one first conductive contact region 15 . For any first conductive contact region 15 , the conductive electrode 20 may cover part of the first conductive contact region 15 or may cover the entire first conductive contact region 15 .

[0103] It should be noted that the material of the conductive electrode 20 and the material of the first connection electrode 17 may be the same or different.

[0104] When the above technical solution is adopted, when the solar cell is in working state, the first semiconductor layer can realize the shunting and collection of carriers. Figures 2 to 4 As shown, the first connection layer 13 disposed on the side of the first semiconductor layer 12 away from the semiconductor substrate 11 is provided with a first conductive contact area 15, and the first passivation layer 16 located in the first conductive contact area 15 is hollowed out, so that one end of the first connection electrode 17 disposed in the first conductive contact area 15 is electrically connected to the first semiconductor layer 12, and the other end is exposed from the first passivation layer 16 and electrically connected to the conductive electrode 20, so as to lead out the carriers collected by the first semiconductor layer 12, which is conducive to the formation of photocurrent and reduces the difficulty of connecting the battery to the external circuit. It is worth noting that the conductive electrode 20 is not only disposed above at least one first conductive contact area 15, but also disposed above part of the first passivation isolation area 14. Furthermore, the first passivation layer 16 in the first connection layer 13 is not only arranged in the first passivation isolation region 14, but also arranged in the first conductive contact region 15 for realizing conductive contact. At this time, the first passivation layer 16 has a large passivation contact area on the first semiconductor layer 12, so that the first semiconductor layer 12 has a high passivation effect, and the carrier recombination rate of the first semiconductor layer 12 on the side away from the semiconductor substrate 11 is reduced. At the same time, compared with the prior art that the nitrogen-containing mask layer is directly heated by a high-temperature laser to completely remove the laser irradiated area of ​​the nitrogen-containing mask layer, the solar cell provided by the embodiment of the present invention also retains part of the first passivation layer 16 located in the first conductive contact region 15. At this time, the requirements of the patterning process on the etching temperature can be reduced, so as to reduce the degree of thermal damage to the semiconductor substrate 11 (or the semiconductor substrate 11 and the first semiconductor layer 12) located below the first passivation layer 16 in the first conductive contact region 15 by the patterning process, thereby improving the yield of the solar cell, which is conducive to the manufactured solar cell having good working performance.

[0105] In actual application, the embodiment of the present invention does not specifically limit the material of the semiconductor substrate, and the semiconductor substrate can be a substrate of any semiconductor material such as a silicon substrate, a silicon germanium substrate, a germanium substrate, or a gallium arsenide substrate. In addition, the conductivity type of the semiconductor substrate can be N-type, P-type, or of course, intrinsic type.

[0106] For the first semiconductor layer, the material of the first semiconductor layer may include any semiconductor material such as silicon, silicon germanium, germanium or gallium arsenide. In terms of the arrangement of the material, the crystal phase of the first semiconductor layer may be amorphous, microcrystalline, nanocrystalline, single crystal or polycrystalline.

[0107] In terms of the formation position, Figure 2 and Figure 5 As shown, in the case where the solar cell provided in the embodiment of the present invention is a double-sided contact cell, the first semiconductor layer 12 can be arranged on a local area of ​​the surface of the semiconductor substrate 11, or can cover the surface of each area of ​​the surface of the semiconductor substrate 11, that is, it is arranged on the entire surface of the semiconductor substrate 11.

[0108] like Figure 3 As shown, in the case where the solar cell provided by the embodiment of the present invention is a back-contact cell, the first semiconductor layer 12 is disposed on a local area of ​​the surface of the semiconductor substrate 11 corresponding to the back side of the cell.

[0109] In addition, if Figure 5 As shown, the first semiconductor layer 12 can be directly disposed on the semiconductor substrate 11. Alternatively, as Figure 6 As shown, the solar cell may further include a first interface passivation layer 28 between the first semiconductor layer 12 and the semiconductor substrate 11. In this case, the passivation contact structure composed of the first interface passivation layer 28 and the first semiconductor layer 12 has an excellent interface passivation effect, and can realize the selective collection of carriers, reduce the carrier recombination rate at the surface of the semiconductor substrate 11 provided with the first interface passivation layer 28 and the first semiconductor layer 12, and further improve the photoelectric conversion efficiency of the solar cell. The material and thickness of the first interface passivation layer 28 can be set according to the material of the first semiconductor layer 12 and actual needs, and are not specifically limited here. For example: when the material of the first semiconductor layer is doped polycrystalline silicon, the first interface passivation layer is a tunneling oxide layer. For another example: when the material of the first semiconductor layer includes at least one of doped amorphous silicon, doped microcrystalline silicon and doped nanocrystalline silicon, the first interface passivation layer is an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, an intrinsic nanocrystalline silicon layer or a mixed layer of the above three.

[0110] In addition, the first semiconductor layer can be a semiconductor layer formed separately on the semiconductor substrate by using processes such as chemical vapor deposition, or can be formed in the semiconductor substrate by directly doping the semiconductor substrate through doping processes such as ion implantation or diffusion.

[0111] In terms of conductivity type, the conductivity type of the first semiconductor layer can be the same as that of the semiconductor substrate, or the conductivity type of the first semiconductor layer can be opposite to that of the semiconductor substrate. Specifically, the conductivity type of the first semiconductor layer can be N-type or P-type.

[0112] It should be noted that when the conductivity type of the first semiconductor layer is the same as the conductivity type of the semiconductor substrate, the solar cell provided in the embodiment of the present invention further includes a second semiconductor layer, and the conductivity type of the second semiconductor layer is opposite to the conductivity type of the first semiconductor layer. The arrangement position of the second semiconductor layer on the semiconductor substrate can be determined according to the type of solar cell.

[0113] For example: Figure 7 and Figure 8 As shown, when the solar cell provided by the embodiment of the present invention is a double-sided contact cell, the second semiconductor layer 22 is arranged on the side of the semiconductor substrate 11 away from the first semiconductor layer 12. Specifically, the second semiconductor layer 22 can be arranged on a local area of ​​the side of the semiconductor substrate 11 away from the first semiconductor layer 12, or can cover the surface of each area of ​​the side of the semiconductor substrate 11 away from the first semiconductor layer 12, that is, the second semiconductor layer 22 covers the entire surface of one side of the semiconductor substrate 11.

[0114] Another example: Figure 3 , Fig. 9 and Fig.10 As shown, when the solar cell provided by the embodiment of the present invention is a back contact cell, the second semiconductor layer 22 and the first semiconductor layer 12 are arranged on the same side of the semiconductor substrate 11. At least a portion of the first semiconductor layer 12 is physically insulated from at least a portion of the second semiconductor layer 22. Specifically, Figure 3 As shown, the first semiconductor layer 12 and the second semiconductor layer 22 may be alternately distributed on the same side of the semiconductor substrate 11; or Fig. 9 As shown, at least a portion of the sidewall of the second semiconductor layer 22 and at least a portion of the sidewall of the first semiconductor layer 12 may also be in contact; or, as shown in FIG. Fig.10 As shown, the second semiconductor layer 22 is not only disposed on the semiconductor substrate 11 , but may also extend to cover a portion of the first semiconductor layer 12 .

[0115] In addition, when the solar cell provided by the embodiment of the present invention is a back-contact cell, each region of the first semiconductor layer may be physically insulated from the second semiconductor layer. In this case, the carrier recombination rate between the first semiconductor layer and the second semiconductor layer of the back-contact cell is low, so that the back-contact cell has a higher conversion efficiency. Alternatively, at least a portion of the first semiconductor layer and at least a portion of the second semiconductor layer may be electrically connected to form a diode structure with a lower reverse breakdown voltage, thereby reducing the risk of hot spots in the back-contact cell and improving the ability of the back-contact cell to resist burning. The size of the leakage contact area between the first semiconductor layer and the second semiconductor layer can be set according to actual needs and is not specifically limited here.

[0116] In addition, if Fig.12 As shown, when the second semiconductor layer 22 is not only disposed on the semiconductor substrate 11, but also extends to cover part of the first semiconductor layer 12, an insulating layer 30 located between the first semiconductor layer 12 and the second semiconductor layer 22 may be disposed in the overlapping region of the first semiconductor layer 12 and the second semiconductor layer 22 to physically insulate the first semiconductor layer 12 from the second semiconductor layer 22. The material of the insulating layer 30 may include any insulating material such as silicon oxide, silicon nitride or silicon oxynitride. Alternatively, the first semiconductor layer and the second semiconductor layer may also be electrically connected in the overlapping region to reduce the risk of hot spots of the back contact battery.

[0117] The material of the second semiconductor layer may include any semiconductor material such as silicon, silicon germanium, germanium or gallium arsenide. In terms of the arrangement of the material, the crystal phase of the second semiconductor layer may be amorphous, microcrystalline, nanocrystalline, single crystal or polycrystalline.

[0118] In addition, if Figure 3 , Fig. 9 and Fig.10 As shown, the second semiconductor layer 22 can be directly disposed on the semiconductor substrate 11. Alternatively, as Fig.11 and Fig.12 As shown, the solar cell may further include a second interface passivation layer 29 at least located between the second semiconductor layer 22 and the semiconductor substrate 11. Fig.12As shown, when the solar cell provided by the embodiment of the present invention is a back contact cell, and the second semiconductor layer 22 also extends to cover part of the first semiconductor layer 12, the second interface passivation layer 29 also extends between the first semiconductor layer 12 and the second semiconductor layer 22. In this case, the passivation contact structure composed of the second interface passivation layer 29 and the second semiconductor layer 22 has an excellent interface passivation effect, and can realize the selective collection of carriers, reduce the carrier recombination rate at the surface of the semiconductor substrate 11 provided with the second interface passivation layer 29 and the second semiconductor layer 22, and further improve the photoelectric conversion efficiency of the solar cell. The material and thickness of the second interface passivation layer 29 can be set according to the material of the second semiconductor layer 22 and actual needs, and are not specifically limited here. For example: when the material of the second semiconductor layer is doped polycrystalline silicon, the second interface passivation layer is a tunneling oxide layer. For another example: when the material of the second semiconductor layer includes at least one of doped amorphous silicon, doped microcrystalline silicon and doped nanocrystalline silicon, the second interface passivation layer is an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, an intrinsic nanocrystalline silicon layer or a mixed layer of the above three.

[0119] It should be noted that, when the conductivity type of the first semiconductor layer is opposite to the conductivity type of the semiconductor substrate, the solar cell provided by the embodiment of the present invention may include the second semiconductor layer or may not include the second semiconductor layer.

[0120] For the first connection layer, Fig.12 As shown, along the thickness direction perpendicular to the first connection layer 13, the first connection layer 13 has a first passivation isolation region 14 and a first conductive contact region 15. The first passivation layer 16 included in the first connection layer 13 is arranged in the first passivation isolation region 14 and the first conductive contact region 15, and is used to passivate the side of the first semiconductor layer 12 away from the semiconductor substrate 11. The first connection electrode 17 included in the first connection layer 13 is arranged in the first conductive contact region 15, and is used to conduct the carriers collected by the first semiconductor layer 12.

[0121] In some embodiments, there is no glass in the first conductive contact area 15 of the first connection layer 13. Since the glass is an insulating material, and there is no glass in the first conductive contact area 15 of the first connection layer 13, the glass can be prevented from affecting the conductivity of the first conductive contact area 15.

[0122] From the material aspect, the material of the first passivation layer may include any insulating passivation material as long as it can be applied to the solar cell provided in the embodiment of the present invention.

[0123] Exemplarily, the first passivation layer may include a nitrogen-containing passivation layer. In this case, the nitrogen-containing passivation layer has good adhesion and is easy to process and manufacture. Secondly, the first passivation layer may also include an oxygen-containing passivation layer.

[0124] Exemplarily, the material of the first passivation layer includes at least one of silicon nitride and silicon oxynitride. In this case, silicon nitride and silicon oxynitride can not only play an insulating and passivation anti-reflection role, but also have a good protective effect, and can well protect the first semiconductor layer located below it. They are insulating passivation materials with relatively comprehensive performance. Therefore, when the material of the first passivation layer includes at least one of silicon nitride and silicon oxynitride, it is beneficial to improve the working performance of the manufactured solar cell. Specifically, when the first passivation layer includes multiple materials, the distribution of different materials in the first passivation layer can be determined according to the actual manufacturing process. For example: in the case where the material of the first passivation layer includes silicon nitride and silicon oxynitride, the silicon nitride material in the first passivation layer can be distributed on the side close to the first semiconductor layer, while the silicon oxynitride material is distributed on the side away from the first semiconductor layer. In addition, in this case, the nitrogen content of the first passivation layer in the first conductive contact area is less than the nitrogen content of the first passivation layer in the first passivation isolation area, which means that the nitrogen-silicon ratio of the first passivation layer in the first conductive contact area is less than the nitrogen-silicon ratio of the first passivation layer in the first passivation isolation area. Specifically, the first passivation layer may be a single-layer structure or a stacked-layer structure composed of multiple materials.

[0125] Exemplarily, in the case where the material of the first passivation layer contains nitrogen, the nitrogen content of the first passivation layer in the first conductive contact area may be less than the nitrogen content of the first passivation layer in the first passivation isolation area. In this case, in the actual manufacturing process, the portion of the first passivation layer located in the first conductive contact area may be heat-treated by laser irradiation or the like, and the first passivation layer located in the first conductive contact area is partially removed after being heated. The specific removal method may be, for example, heat vaporization, heat film explosion, or heat to volatilize the nitrogen element therein in the form of nitrogen gas, so that in the first passivation layer after heat treatment, the nitrogen content of the portion located in the first conductive contact area is reduced, and a hollow structure such as a hole may be formed in the first passivation layer, so that the first passivation layer is hollowed out in the first conductive contact area, which is beneficial to the manufacture of the first connection electrode. It can be seen that compared with the prior art in which the nitrogen-containing mask layer is directly heated by a high-temperature laser to completely remove the laser irradiated area of ​​the nitrogen-containing mask layer, in the solar cell provided by the embodiment of the present invention, only the nitrogen content of the first passivation layer in the first conductive contact area is set to be less than the nitrogen content of the first passivation layer in the first passivation isolation area, and only a portion of the first passivation layer located in the first conductive contact area is removed. Therefore, a laser with lower energy can be used to irradiate the first conductive contact area. In this way, the degree of thermal damage caused by the patterning treatment to the portion of the semiconductor substrate (or to the semiconductor substrate and the first semiconductor layer) located below the first nitrogen-containing passivation layer in the first conductive contact area can be reduced, thereby improving the yield of the solar cell and facilitating the manufactured solar cell to have good working performance.

[0126] Exemplarily, the surface of the first passivation layer located in at least part of the first conductive contact region may include an oxide layer. In this case, since the performance of the oxide is more stable, the surface of the first passivation layer located in at least part of the first conductive contact region is formed with an oxide layer, which can further improve the stability of the first passivation layer and further improve the reliability of the solar cell. The above-mentioned oxide layer may include a silicon oxide layer and / or a silicon oxynitride layer, etc.

[0127] In some embodiments, if the thickness of the oxide layer is too thick, the manufacturing difficulty is greater, and if the thickness of the oxide layer is too low, the stability of the first passivation layer is affected; therefore, in this technical solution, the thickness of the oxide layer can be 10% to 50% of the thickness of the first passivation layer, so that while ensuring the stability of the first passivation layer, the processing difficulty of the oxide layer is reduced. Exemplarily, the thickness of the oxide layer is 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48% or 50% of the thickness of the first passivation layer.

[0128] In addition, the material of the oxide layer may include silicon oxide and / or silicon oxynitride. In some examples, silicon atoms on the surface of the first passivation layer located at least in part of the first conductive contact region come into contact with oxygen and react to form an oxide layer. Alternatively, the oxide layer may be formed by a process such as chemical vapor deposition.

[0129] In some embodiments, the oxygen content in the first passivation layer located in at least part of the first conductive contact region can be gradually reduced along the direction close to the first semiconductor layer. In this way, the outer surface of the first passivation layer located in at least part of the first conductive contact region has the largest oxygen content and the most stable performance, which can further improve the stability of the first passivation layer.

[0130] As for the material of the first connecting electrode, it can include any conductive material as long as it can be applied to the solar cell provided in the embodiment of the present invention.

[0131] Exemplarily, the material of the first connection electrode may include one or more of gold, silver, copper, aluminum, nickel, chromium, titanium and tin. In this case, the material of the first connection electrode has a variety of optional types. And the manufacturing process of the first connection electrode corresponding to different material types may be different. Therefore, when the material of the first connection electrode includes the above types, a variety of manufacturing processes can be used to form the first connection electrode, which is conducive to improving the applicability of the solar cell provided by the embodiment of the present invention in different application scenarios.

[0132] As for the thickness and refractive index of the first passivation layer, they can be set according to actual needs and are not specifically limited here.

[0133] Exemplarily, the thickness of the first passivation layer may be greater than or equal to 2 nm and less than or equal to 350 nm. For example, the thickness of the first passivation layer may be 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm or 350 nm, etc.

[0134] Among them, the thickness of the parts of the first passivation layer located in different areas can be the same. For example, the thickness of the part of the first passivation layer located in the first passivation isolation area and the part of the first passivation layer located in the first conductive contact area can be the same. Alternatively, the thickness of the first passivation layer located in the first conductive contact area can also be less than the thickness of the first passivation layer located in the first passivation isolation area. In this case, it is helpful to reduce the difficulty and / or heat treatment temperature of the first passivation layer located in the first conductive contact area, further reduce the degree of damage to the first semiconductor layer and the semiconductor substrate after patterning, and improve the yield and working performance of solar cells. Specifically, the thickness difference and thickness range of the parts of the first passivation layer located in different areas can be set according to actual needs, and are not specifically limited here.

[0135] Exemplarily, the thickness of the first passivation layer in the first conductive contact area is less than or equal to 350nm. In this case, the thickness of the first passivation layer in the first conductive contact area is within the above range, which can prevent the difficulty of hollowing out the first passivation layer in the first conductive contact area due to the large thickness of the first passivation layer in the first conductive contact area and / or the high heat treatment temperature, further reducing the degree of damage to the first semiconductor layer and the semiconductor substrate after patterning; at the same time, it can also prevent the first connection electrode from being difficult to fill the hollow area of ​​the first passivation layer due to the large thickness of the first passivation layer in the first conductive contact area, ensuring that one end of the first connection electrode along the thickness of the first passivation layer can be electrically connected to the first semiconductor layer, and the other end is exposed in the first passivation layer. In addition, the large thickness of the first passivation layer in the first conductive contact area will also lead to a long time required to prepare the first connection electrode, affecting the production efficiency of solar cells.

[0136] In addition, the thickness of the first passivation layer in the first conductive contact region may be greater than 2 nm. In this case, it is helpful to prevent the first passivation layer in the first conductive contact region from having a low passivation effect due to the small thickness of the first passivation layer in the first conductive contact region, and it is helpful to reduce the carrier recombination rate on the side of the first semiconductor layer in the first conductive contact region away from the semiconductor substrate, thereby improving the conversion efficiency of the solar cell.

[0137] Specifically, the thickness of different parts of the first passivation layer located in the non-hollowed area of ​​the first conductive contact area may be the same or different. In some examples, the thickness of the part of the first passivation layer close to the edge of the hole may be greater than the thickness of the part of the first passivation layer away from the edge of the hole, so as to improve the passivation effect of the part of the first passivation layer close to the edge of the hole and reduce the risk of leakage. In addition, the part of the first passivation layer located in the first conductive contact area may be provided with a blind hole, and the thickness of the part provided with the blind hole is less than the thickness of other parts of the first passivation layer located in the non-hollowed area of ​​the first conductive contact area. In addition, it should be noted that the thickness range of the first passivation layer located in the first conductive contact area less than or equal to 350nm can be the thickness range of the first passivation layer located in the first conductive contact area when the first passivation layer is a single-layer structure, or it can be the total thickness of the first passivation layer located in the first conductive contact area when it is a stacked structure (such as a stacked structure of silicon nitride and silicon oxynitride, such as a stacked structure of silicon nitride and silicon oxide, such as a stacked structure of silicon oxynitride and silicon oxide, such as a stacked structure of silicon nitride, silicon oxynitride and silicon oxide).

[0138] Exemplarily, the refractive index of the first passivation layer may be greater than or equal to 1.5 and less than or equal to 3. In this case, the refractive index of the first passivation layer is set within a reasonable range, which is conducive to reducing the reflectivity of the first passivation layer to incident light and improving light utilization.

[0139] In the actual application process, it can be understood that in the first passivation layer, the ratio of the area of ​​the hollow region to the area of ​​the first passivation layer will affect the contact area between the first connection electrode and the first semiconductor layer, and thus affect the contact resistance between the two. Therefore, the ratio of the area of ​​the hollow region to the area of ​​the first passivation layer and the ratio of the area in the first conductive contact region can be determined according to the requirements for the contact performance between the first connection electrode and the first semiconductor layer in the actual application scenario, and no specific limitation is made here.

[0140] Exemplarily, in the first passivation layer, the area of ​​the hollow region and the area of ​​the first passivation layer account for more than or equal to 0.1% and less than or equal to 80%. For example, the area of ​​the hollow region and the area of ​​the first passivation layer may account for 0.1%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70% or 80%, etc. In this case, it is possible to prevent the contact area between the first connection electrode and the first semiconductor layer from being too small due to the hollow region accounting for too small an area, thereby reducing the contact resistance between the first connection electrode and the first semiconductor layer. It is also possible to prevent the passivation contact area between the first passivation layer and the first semiconductor layer from being too small due to the hollow region accounting for too large an area, thereby facilitating the first passivation layer to have a higher passivation effect on the first semiconductor layer, thereby reducing the carrier recombination rate on the side of the first semiconductor layer away from the semiconductor substrate.

[0141] In addition, in the actual application process, such as Figures 13 to 15 As shown, the first passivation layer 16 is hollowed out in the first conductive contact area 15, and the portion of the first passivation layer 16 located in the first conductive contact area 15 may have a plurality of holes 18 penetrating the first passivation layer 16. In this case, the first connection electrode 17 may penetrate the first passivation layer 16 through the holes 18 disposed in the first passivation layer 16 in the first conductive contact area 15, thereby leading out the carriers collected by the first semiconductor layer 12 and reducing the carrier recombination rate.

[0142] It is understandable that the size of the above-mentioned hole size will not only affect the contact area between the first connecting electrode and the first semiconductor layer. Moreover, the formation of the hole is due to the heat treatment of the first passivation layer located in the first conductive contact area, so that the hole is formed by heat gasification, heat explosion or volatilization of heated gas. Based on this, the higher the temperature of the heat treatment, the larger the pore size and / or number of the holes formed in the first passivation layer. On the contrary, the lower the temperature of the heat treatment, the smaller the pore size and / or number of the holes formed in the first passivation layer. In the above case, the size of the hole can be determined according to the requirements for the contact area between the first connecting electrode and the first semiconductor layer in the actual application scenario, and the requirements for the degree of damage to the first semiconductor layer and the semiconductor substrate in the first conductive contact area, and no specific limitation is made here.

[0143] Exemplarily, the maximum pore size of at least one hole may be greater than or equal to 5nm and less than or equal to 40μm. For example, the size of at least one hole may be 5nm, 10nm, 50nm, 100nm, 200nm, 300nm, 500nm, 600nm, 800nm, 900nm, 1μm, 5μm, 10μm, 15μm, 20μm, 30μm or 40μm, etc. In this case, the maximum pore size of at least one hole is within the above range, which is conducive to preventing the first connection electrode from being electrically connected to the first semiconductor layer through the hole due to the maximum pore size of the hole being too small, and can avoid the contact resistance between the first connection electrode and the first semiconductor layer being large, further reducing the carrier recombination rate on the side of the first semiconductor layer away from the semiconductor substrate, and helping to improve the conversion efficiency of the solar cell. In addition, it can also prevent the heat treatment temperature of the first passivation layer from being too high due to the excessive size of the hole, further reduce the degree of thermal damage to the semiconductor substrate after patterning, improve the yield of the manufactured solar cell, and help the solar cell have good working performance. It should be noted that in the actual application process, Fig.13As shown, there may be a situation where adjacent holes 18 are connected, and in this case, multiple connected holes 18 are considered to be one hole 18. Accordingly, the maximum aperture of multiple connected holes 18 is the aperture of the formed hole 18. It can be understood that when multiple holes 18 are connected to form one hole, along the direction intersecting the connection direction of the multiple holes 18, such as the direction perpendicular or approximately perpendicular to the connection direction, the size of the hole is smaller, and the size is close to the size of other single holes 18.

[0144] The apertures of different holes may be the same or different. Fig.12 As shown, along the thickness direction of the first passivation layer 16, the apertures of the various parts of at least one hole may be the same, or in at least one hole, the size of the hole opening on the side away from the first semiconductor layer 12 may be larger than the size of the hole bottom on the side close to the first semiconductor layer 12. Alternatively, as Fig.15 As shown, in at least one hole 18, the size of the hole opening on the side away from the first semiconductor layer may also be smaller than the size of the hole bottom on the side close to the first semiconductor layer.

[0145] It is worth noting that Fig.15 As shown, when the size of the hole opening on the side away from the first semiconductor layer in at least one hole 18 is smaller than the size of the hole bottom on the side close to the first semiconductor layer, the size of the first connection electrode set at the hole bottom of the hole 18 is larger, which is conducive to a larger contact area between the first connection electrode and the first semiconductor layer, and reduces the contact resistance between the two. The hole opening size of the hole 18 on the side away from the first semiconductor layer is smaller, which is conducive to enhancing the adhesion between the first connection electrode and the first passivation layer 16 located in the first conductive contact area, reducing the risk of the first connection electrode falling off from the first passivation layer 16, enhancing the contact performance and contact strength between the first connection electrode and the first semiconductor layer, and improving the yield of the solar cell.

[0146] Exemplarily, in at least one first conductive contact region, the ratio of the total area of ​​the holes in the first conductive contact region to the area of ​​the first conductive contact region is greater than or equal to 1% and less than or equal to 20%. The application principle of the beneficial effect in this case can refer to the application principle of the beneficial effect of the maximum pore size of at least one hole being greater than or equal to 5nm and less than or equal to 40μm described above, and will not be repeated here.

[0147] As for the morphology of the above-mentioned holes, it can be set according to the aperture relationship of different parts of the holes along the thickness direction of the first passivation layer and actual needs, and is not specifically limited here.

[0148] For example, at least one hole may be cylindrical, bowl-shaped or gourd-shaped. In this case, the morphology of the hole has a variety of examples, which is conducive to improving the applicability of the solar cell provided by the embodiment of the present invention in different practical application environments. In addition, it is also conducive to reducing the difficulty of the manufacturing process of forming the hole in the first passivation layer located in the first conductive contact area.

[0149] The hole may be in a relatively regular shape such as a cylindrical shape, a bowl shape or a gourd shape, or may be in an irregular shape of the hole wall.

[0150] As for the distribution of the holes in the first passivation layer located in the first conductive contact region, it can be arranged according to the surface morphology of the first passivation layer facing away from the first semiconductor layer and actual needs, and is not specifically limited here.

[0151] Exemplarily, the holes may be uniformly distributed in the first passivation layer located in the first conductive contact region.

[0152] For example, Figure 4 , Fig.13 and Fig.14 As shown, in the case where the first passivation layer 16 has a texture structure 19 on the side away from the first semiconductor layer, in the first conductive contact area, the holes 18 can be distributed at least at the ridges of the texture structure 19. In this case, because the first passivation layer 16 is formed on the side of the first semiconductor layer away from the semiconductor substrate by chemical vapor deposition and other processes, the surface morphology of the first passivation layer 16 can often reflect the surface morphology of the first semiconductor layer away from the semiconductor substrate. It can be understood that compared with the inside of the texture structure 19, due to the undulating morphology at the ridges of the texture structure 19, the specific surface area at the ridges is larger, and the specific surface area of ​​the corresponding first semiconductor layer at the ridges of the texture structure 19 corresponding to the first passivation layer 16 is also relatively large. Based on this, when the holes 18 are distributed at least at the ridges of the texture structure 19, it is beneficial to increase the contact area between the first connection electrode 17 and the first semiconductor layer through the holes 18, and further reduce the contact resistance between the two. In addition, the deposited film thickness of the first passivation layer 16 is inversely proportional to the specific surface area of ​​the surface on which it is deposited. Therefore, the deposited film thickness of the first passivation layer 16 at the ridge of the texture structure 19 with a relatively large specific surface area is relatively small. Moreover, when the laser acts on the first conductive contact area, since the structure at the ridge is more prominent, the laser energy is concentrated on the ridge position, which is conducive to forming a through hole 18 in the portion of the first passivation layer 16 corresponding to the ridge, thereby reducing the process difficulty of hollowing out the first passivation layer 16 located in the first conductive contact area, thereby improving the yield and working performance of solar cells.

[0153] In the embodiment of the present application, the texture structure may be a tower base texture structure or a texture structure of other shapes, for example, a regular or irregular texture structure composed of at least one straight ridge line and / or at least one curved ridge line. The texture structure has concave-convex changes at the ridge line.

[0154] Among them, Figure 4 and Fig.14 As shown, in the case where the first passivation layer 16 has a texture structure 19 on the side facing away from the first semiconductor layer, in the first conductive contact area, the holes 18 may be distributed only at the ridges of the texture structure 19. Alternatively, the holes 18 may be distributed at the ridges and inside the texture structure 19. In this case, the holes 18 are distributed not only at the ridges of the texture structure 19, but also inside the texture structure 19, which is beneficial to increase the number of holes 18 in the first passivation layer 16 located in the first conductive contact area, thereby increasing the contact area between the first connection electrode 17 and the first semiconductor layer 12, and improving the contact performance between the first connection electrode 17 and the first semiconductor layer.

[0155] When the holes are distributed at the ridges and inside the texture structure, in the first conductive contact region, the distribution density of the holes at the ridges of the texture structure may be equal to the distribution density of the holes inside the texture structure; or Figure 4 and Fig.15 As shown, in the first conductive contact area, the distribution density of the holes 18 at the ridges of the texture structure 19 may be greater than the distribution density of the holes 18 in the texture structure 19. In other words, in the first conductive contact area, the distribution density of the holes 18 at the ridges of the texture structure 19 is greater, which is beneficial to further increase the contact area between the first connection electrode 17 and the first semiconductor layer through the holes 18, and further reduce the process difficulty of hollowing out the first passivation layer 16 located in the first conductive contact area 15, thereby improving the yield and working performance of the solar cell.

[0156] In another example, if Fig.16 As shown, the first passivation layer is hollowed out in the first conductive contact area 15, or the first passivation layer is randomly distributed in the first conductive contact area 15. In this case, the first passivation layer in the first conductive contact area 15 is irregularly distributed. Fig.16 , the hollowed-out area of ​​the first passivation layer is irregular, rather than Fig.13 The nearly circular hole shown, or a plurality of nearly circular holes connected together, provides another example of the solar cell provided by the embodiment of the present invention, thereby improving the applicability of the solar cell provided by the embodiment of the present invention in different application scenarios.

[0157] Specifically, when the first passivation layer is randomly distributed in the first conductive contact area, the distribution, morphology and size of the hollow area of ​​the first passivation layer located in the first conductive contact area can be set according to actual needs, and are not specifically limited here. Exemplarily, in this case, the thickness of the first passivation layer located in the first conductive contact area can be less than the thickness of the first passivation layer located in the first passivation isolation area to reduce the contact resistance between the conductive electrode and the first semiconductor layer. In the actual manufacturing process, a laser can be used to partially remove part of the thickness of the first passivation layer located in the first conductive contact area.

[0158] In addition, illustratively, in the case where the first passivation layer is scattered in the first conductive contact area, in at least one first conductive contact area, the ratio of the total area of ​​the hollow area of ​​the first conductive contact area to the area of ​​the first conductive contact area can be greater than or equal to 1% and less than or equal to 95%. For example: the ratio of the total area of ​​the hollow area of ​​the first conductive contact area to the area of ​​the first conductive contact area can be 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%, etc. The application principle of the beneficial effect in this case can refer to the application principle of the beneficial effect described above that the area of ​​the hollow area in the first passivation layer accounts for greater than or equal to 0.1% and less than or equal to 80% of the area of ​​the first passivation layer, which will not be repeated here.

[0159] As for the first connecting electrode disposed in the first conductive contact region, Figures 2 to 4 As shown, one end of the first connection electrode 17 along the thickness direction of the first passivation layer 16 is electrically connected to the first semiconductor layer 12, and the other end may only expose the first passivation layer 16. At this time, the first connection electrodes 17 located in different hollow areas are not electrically connected, and the first connection electrode 17 does not completely cover the first conductive contact area 15. Or, as Fig.17 As shown, the end of the first connection electrode 17 away from the first semiconductor layer 12 may also expose the first passivation layer 16, and be disposed on at least a portion of the first passivation layer 16 located in the first conductive contact region 15. At this time, the portions of the first connection electrode 17 located in different hollowed-out regions of the same first conductive contact region 15 are electrically connected together. In this case, the first connection electrode 17 may completely cover the first conductive contact region 15, or may cover a portion of the first conductive contact region 15.

[0160] As for the conductive electrode, the material of the conductive electrode may include any conductive material such as silver, aluminum, copper, titanium or nickel, as long as it can be applied to the manufacturing method provided in the embodiment of the present invention.

[0161] The setting range of the conductive electrode on the side of the first connection layer away from the first semiconductor layer can be set according to actual needs and is not specifically limited here. In actual application, the width of the conductive electrode can be equal to the width of the first conductive contact area, or can be smaller than or larger than the width of the first conductive contact area. Specifically, the difference in width between the first conductive contact area and the conductive electrode can be determined according to the actual application scenario. Figure 3 As shown, the first conductive contact area refers to an area with a roughly regular shape and in which different first connection electrodes are electrically connected, that is, it refers to an area surrounded by the outermost first connection electrodes in the area where the first connection electrodes are formed.

[0162] Exemplarily, the ratio between the width of the conductive electrode and the width of the first conductive contact region may be greater than or equal to 0.6 and less than or equal to 2. For example, the ratio between the width of the conductive electrode and the width of the first conductive contact region may be 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.8 or 2, etc. In this case, the width range of the first conductive contact region is relatively large, which is conducive to improving the applicability of the solar cell provided by the embodiment of the present invention in different application scenarios.

[0163] In addition, in the actual application process, such as Fig.19 As shown, the first passivation layer located in the first passivation isolation region may include an amorphous state, and the first passivation layer located in at least part of the first conductive contact region may include a crystalline state. In this case, the first passivation layer itself is in an amorphous state, and the portion located in at least part of the first conductive contact region is crystalline after being processed; for example, the first passivation layer located in at least part of the first conductive contact region is crystalline after being irradiated with a laser. The structural stability of the first passivation layer located in at least part of the first conductive contact region can be enhanced, thereby improving the reliability of the solar cell and extending its service life. In addition, the first passivation layer located in at least part of the first conductive contact region appears in a crystalline state, which can also improve the conductivity of the first passivation layer located in at least part of the first conductive contact region, which is conducive to reducing the contact resistance between the surface of the first passivation layer located in at least part of the first conductive contact region and the first connecting electrode and / or the conductive electrode, and reducing current loss. Among them, the first passivation layer located in at least part of the first conductive contact region may also include an amorphous state, so as to further reduce the temperature requirement for heat treatment of the first passivation layer located in the first conductive contact region, and reduce the degree of thermal damage to the first semiconductor layer and the semiconductor substrate.

[0164] In some embodiments, the crystalline state includes one or more of crystalline silicon, crystalline silicon nitride, and crystalline silicon oxynitride. Specifically, the crystalline state formed by the first passivation layer located in at least part of the first conductive contact region may include only crystalline silicon, may include only crystalline silicon nitride, or may include only crystalline silicon oxynitride. Alternatively, the crystalline state formed by the first passivation layer located in at least part of the first conductive contact region may include any two of crystalline silicon, crystalline silicon nitride, and crystalline silicon oxynitride; or, the crystalline state includes crystalline silicon, crystalline silicon nitride, and crystalline silicon oxynitride. Among them, the size of crystalline silicon, crystalline silicon nitride, and / or crystalline silicon oxynitride is 0.01nm to 100nm, for example, the size of crystalline silicon, crystalline silicon nitride, and / or crystalline silicon oxynitride is 0.01nm, 1nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm, etc. For example, the crystalline silicon is nanocrystalline silicon.

[0165] In other embodiments, the degree of crystallization of the first passivation layer located in at least part of the first conductive contact area can be gradually reduced from the surface of the first passivation layer located in at least part of the first conductive contact area that is irradiated by the laser to the surface that is not irradiated by the laser. In this way, the degree of crystallization of the first passivation layer located in at least part of the first conductive contact area on the surface is higher, thereby making the anti-reflection effect of the first passivation layer located in at least part of the first conductive contact area near the surface better and the reliability better. In addition, the surface of the first passivation layer located in at least part of the first conductive contact area has a higher degree of crystallization, so that the conductivity of the first passivation layer located in at least part of the first conductive contact area near the surface is better, which is beneficial to reduce the contact resistance between the surface of the first passivation layer located in at least part of the first conductive contact area and the first connecting electrode and / or the conductive electrode, and reduce current loss.

[0166] In addition, in the case where the solar cell further comprises a second semiconductor layer, such as Fig. 20As shown, when the second semiconductor layer 22 and the first semiconductor layer 12 are arranged on the same side of the semiconductor substrate 11, the first connection layer 13 can be arranged only on the side of the first semiconductor layer 12 away from the semiconductor substrate 11, and not on the side of the second semiconductor layer 22 away from the semiconductor substrate 11; at this time, the solar cell may also include a passivation connection layer arranged on the side of the second semiconductor layer 22 away from the semiconductor substrate 11. The passivation connection layer has a second passivation isolation region 27 and a second conductive contact region 23. The passivation connection layer includes a passivation layer arranged in the second passivation isolation region 27, and a second connection electrode 24 arranged in the second conductive contact region 23, that is, the passivation layer is only arranged in the second passivation isolation region 27. The material of the above-mentioned passivation layer may include any insulating passivation material such as silicon oxide, silicon nitride or silicon oxynitride. The material of the second connection electrode 24 may include any conductive material such as silver, copper, aluminum or titanium, as long as it can be applied to the solar cell provided in the embodiment of the present invention. Or, as Fig.21 As shown, the first connection layer 13 may also have a second conductive contact area 23; and the first passivation layer 16 is also arranged in the second conductive contact area 23; the first passivation layer 16 is hollowed out in the second conductive contact area 23; the first connection layer 13 also includes a second connection electrode 24 arranged in the second conductive contact area 23; one end of the second connection electrode 24 along the thickness direction of the first passivation layer 16 is electrically connected to the second semiconductor layer 22, and the other end of the second connection electrode 24 is exposed from the first passivation layer 16. In this case, the specific arrangement of the first passivation layer 16 in the second conductive contact area 23 as a hollow arrangement, and the material of the second connection electrode 24, etc., can refer to the specific arrangement of the first passivation layer 16 in the first conductive contact area 15 as a hollow arrangement, and the material of the first connection electrode 17, etc., which will not be repeated here. In addition, when the first passivation layer 16 is a nitrogen-containing passivation layer, the nitrogen content of the first passivation layer 16 in the second conductive contact region 23 may be less than the nitrogen content of the first passivation layer 16 in the first passivation isolation region 14; at this time, the difference in nitrogen content of the first passivation layer 16 in the second conductive contact region 23 and the first passivation isolation region 14 and the application principle of the beneficial effect can refer to the difference in nitrogen content of the first passivation layer 16 in the first conductive contact region 15 and the first passivation isolation region 14 and the application principle of the beneficial effect, which will not be repeated here. Or, Fig. 22As shown, when the first semiconductor layer 12 and the second semiconductor layer 22 are respectively arranged on opposite sides of the semiconductor substrate 11, the solar cell may further include a passivation connection layer arranged on the side of the second semiconductor layer 22 away from the semiconductor substrate 11. The passivation connection layer has a second passivation isolation region 27 and a second conductive contact region 23. The passivation connection layer includes a passivation layer arranged in the second passivation isolation region 27, and a second connection electrode 24 arranged in the second conductive contact region 23, that is, the passivation layer is only arranged in the second passivation isolation region 27. The materials of the above-mentioned passivation layer and the second connection electrode 24 may include the above-mentioned materials, which will not be repeated here. Or, as Fig.23 As shown, the above-mentioned solar cell also includes a second connection layer 25; along the thickness direction perpendicular to the second connection layer 25, the second connection layer 25 has a second passivation isolation area 27 and a second conductive contact area 23; the second connection layer 25 includes a second passivation layer 26 arranged in the second passivation isolation area 27 and the second conductive contact area 23, and a second connection electrode 24 arranged in the second conductive contact area 23; the second passivation layer 26 is hollowed out in the second conductive contact area 23, and one end of the second connection electrode 24 along the thickness direction of the second passivation layer 26 is electrically connected to the second semiconductor layer 22, and the other end of the second connection electrode 24 is exposed from the second passivation layer 26.

[0167] In some examples, the area of ​​the first conductive contact region 15 may be the same as or different from the area of ​​the second conductive contact region 23. When the area of ​​the first conductive contact region 15 is different from the area of ​​the second conductive contact region 23, the area of ​​the first conductive contact region 15 may be greater than the area of ​​the second conductive contact region 23, or the area of ​​the first conductive contact region 15 may be less than the area of ​​the second conductive contact region 23. In some examples, the first semiconductor layer 12 is a P-type semiconductor layer, and the area of ​​the first conductive contact region 15 is greater than the area of ​​the second conductive contact region 23.

[0168] In some examples, the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 may be the same as or different from the total area of ​​all the second conductive contact regions 23 in the first connection layer 13. In the case where the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 is different from the total area of ​​all the second conductive contact regions 23 in the first connection layer 13, the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 may be greater than the total area of ​​all the second conductive contact regions 23 in the first connection layer 13, or the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 may be less than the total area of ​​all the second conductive contact regions 23 in the first connection layer 13. In some examples, the first semiconductor layer 12 is a P-type semiconductor layer, and the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 is greater than the total area of ​​all the second conductive contact regions 23 in the first connection layer 13.

[0169] As a possible implementation scheme, the area of ​​the hollow region of the first conductive contact region 15 may be different from or different from the area of ​​the hollow region of the second conductive contact region 23. In the case where the area of ​​the hollow region of the first conductive contact region 15 is different from the area of ​​the hollow region of the second conductive contact region 23, the area of ​​the hollow region of the first conductive contact region 15 may be greater than the area of ​​the hollow region of the second conductive contact region 23, or the area of ​​the hollow region of the first conductive contact region 15 may be smaller than the area of ​​the hollow region of the second conductive contact region 23. In some examples, the first semiconductor layer 12 is a P-type semiconductor layer, and the area of ​​the hollow region of the first conductive contact region 15 is greater than the area of ​​the hollow region of the second conductive contact region 23.

[0170] As a possible implementation scheme, the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 may be the same as or different from the total area of ​​all the second conductive contact regions 23 in the second connection layer 25. In the case where the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 is different from the total area of ​​all the second conductive contact regions 23 in the second connection layer 25, the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 may be greater than the total area of ​​all the second conductive contact regions 23 in the second connection layer 25, or the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 may be less than the total area of ​​all the second conductive contact regions 23 in the second connection layer 25. In some examples, the first semiconductor layer 12 is a P-type semiconductor layer, and the total area of ​​all the first conductive contact regions 15 in the first connection layer 13 is greater than the total area of ​​all the second conductive contact regions 23 in the second connection layer 25.

[0171] As a possible implementation scheme, the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 may be the same as or different from the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the first connection layer 13. In the case where the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 is different from the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the first connection layer 13, the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 may be greater than the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the first connection layer 13, or the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 may be less than the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the first connection layer 13. In some examples, the first semiconductor layer 12 is a P-type semiconductor layer, and the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 is greater than the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the first connection layer 13.

[0172] As a possible implementation scheme, the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 may be the same as or different from the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the second connection layer 25. In the case where the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 is different from the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the second connection layer 25, the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 may be greater than the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the second connection layer 25, or the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 may be less than the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the second connection layer 25. In some examples, the first semiconductor layer 12 is a P-type semiconductor layer, and the total area of ​​the hollowed-out regions of all the first conductive contact regions 15 in the first connection layer 13 is greater than the total area of ​​the hollowed-out regions of all the second conductive contact regions 23 in the second connection layer 25.

[0173] Among them, in the above-mentioned second connection layer, the specific configuration mode of the second passivation layer in the second conductive contact area being hollowed out, and the material of the second connection electrode, etc. can refer to the specific configuration mode of the first passivation layer in the first conductive contact area being hollowed out, and the material of the first connection electrode, etc., which are not repeated here. In addition, in the case where the second passivation layer is a nitrogen-containing passivation layer, the nitrogen content of the second passivation layer in the second conductive contact area can be less than the nitrogen content of the second passivation layer in the second passivation isolation area; at this time, the difference in nitrogen content of the second passivation layer in the second conductive contact area and the second passivation isolation area and the application principle of the beneficial effect can refer to the difference in nitrogen content of the first passivation layer in the first conductive contact area and the first passivation isolation area and the application principle of the beneficial effect, which are not repeated here.

[0174] It is worth noting that, as mentioned above, when the first passivation layer is also arranged in the above-mentioned second conductive contact area, or when the solar cell also includes the above-mentioned second connecting layer, the first passivation layer (or the second passivation layer) can have a larger passivation contact area on the second semiconductor layer, so that it has a higher passivation effect on the second semiconductor layer, thereby reducing the carrier recombination rate on the side of the second semiconductor layer away from the semiconductor substrate.

[0175] In one example, if Fig.24 As shown, the solar cell may further include a surface passivation layer 21 disposed between the first semiconductor layer 12 and the first connection layer 13. The first connection electrode 17 penetrates the surface passivation layer 21 and is electrically connected to the first semiconductor layer 12. In this case, the surface passivation layer 21 may passivate the side of the first semiconductor layer 12 away from the semiconductor substrate 11, further reducing the carrier recombination rate on the side of the first semiconductor layer 12 away from the semiconductor substrate 11.

[0176] The material and thickness of the surface passivation layer can be set according to actual needs and are not specifically limited here. For example, the material of the surface passivation layer can include any material with passivation effect, such as silicon oxide, aluminum oxide, intrinsic silicon, etc.

[0177] In a second aspect, an embodiment of the present invention provides a method for manufacturing a solar cell. Figures 25 to 33 The manufacturing process is described by referring to the cross-sectional view of the operation shown in FIG. 1 . Specifically, the manufacturing method of the solar cell includes the following steps:

[0178] First, a semiconductor substrate is provided. Specifically, the material and conductivity type of the semiconductor substrate can be referred to above and will not be described in detail here.

[0179] Next, if Fig.25As shown, a first semiconductor layer 12 is formed on the semiconductor substrate 11. The material, conductivity type and crystal phase of the first semiconductor layer 12 can be referred to in the above text and will not be described here. As for the manufacturing process of the first semiconductor layer 12, it can be determined according to the type of solar cell and the formation range of the first semiconductor layer 12 on the semiconductor substrate 11, and no specific limitation is made here.

[0180] Exemplarily, a process such as chemical vapor deposition can be used to form an intrinsic semiconductor layer for manufacturing the first semiconductor layer on a semiconductor substrate. Then. The intrinsic semiconductor layer is doped by diffusion, ion implantation or doping source coating to form the first semiconductor layer. Among them, if the first semiconductor layer is arranged on a local area of ​​the surface of the semiconductor substrate, it is also necessary to selectively etch the first semiconductor layer by dry etching, wet etching, laser etching or chemical slurry etching under the protection of the mask layer, and only retain the first semiconductor layer located on the partial area. Specifically, the above-mentioned mask layer may include any film layer with mask layer protection function, such as a silicon oxide layer, a doped silicon glass layer, a silicon nitride layer, a silicon oxynitride layer or an aluminum oxide layer, as long as it can be applied to the manufacturing method provided in the embodiment of the present invention. Secondly, the embodiment of the present invention does not specifically limit the formation method of the mask layer. It can be formed by using a process such as chemical vapor deposition to cover the side of the first semiconductor layer away from the semiconductor substrate. Then, a laser etching process is used to directly remove part of the mask layer; or, a laser may be first used to irradiate part of the mask layer to make the structure of the part of the mask layer irradiated by the laser loose, and then a wet etching process or the like is used to remove the part of the mask layer irradiated by the laser. Of course, other methods may also be used to form the mask layer.

[0181] In the actual manufacturing process, Fig.25 As shown, the above method can be used to directly form the first semiconductor layer 12 on the semiconductor substrate 11. Alternatively, as Fig.26 As shown, when the manufactured solar cell also includes a first interface passivation layer 28, it is also necessary to form a first interface passivation layer 28 as a whole layer on the semiconductor substrate 11 by using a process such as thermal oxidation or chemical vapor deposition before forming the intrinsic semiconductor layer. If the first semiconductor layer 12 is only provided on a local area of ​​the surface of the semiconductor substrate 11, the first interface passivation layer 28 can be selectively etched before the intrinsic semiconductor layer as a whole layer is formed; or, after the first semiconductor layer 12 as a whole layer is formed, the first semiconductor layer 12 and the first interface passivation layer 28 can be selectively etched under the protection of the same mask layer. The material and thickness of the first interface passivation layer 28 can refer to the above.

[0182] In addition, if Fig.25 and Fig.26As shown, the first semiconductor layer 12 may be formed only on the semiconductor substrate 11 (or the first semiconductor layer 12 and the first interface passivation layer 28 may be formed); or Fig. 27 As shown, the first semiconductor layer 12 and the surface passivation layer 21 may also be formed in sequence on the semiconductor substrate 11. The material of the surface passivation layer 21 may refer to the above.

[0183] Next, if Figure 28 to Figure 32 As shown, a first connection layer 13 is formed on the side of the first semiconductor layer 12 away from the semiconductor substrate 11. In the thickness direction perpendicular to the first connection layer 13, the first connection layer 13 has a first passivation isolation region 14 and a first conductive contact region 15, wherein the first connection layer 13 includes a first passivation layer 16 disposed in the first passivation isolation region 14 and the first conductive contact region 15, and a first connection electrode 17 disposed in the first conductive contact region 15. The first passivation layer 16 is hollowed out in the first conductive contact region 15, and one end of the first connection electrode 17 along the thickness direction of the first passivation layer 16 is electrically connected to the first semiconductor layer 12, and the other end of the first connection electrode 17 is exposed from the first passivation layer 16.

[0184] The materials of the first passivation layer and the first connection electrode, as well as the hollowing arrangement of the first passivation layer in the first conductive contact region, etc. can refer to the corresponding information in the solar cell provided in the first aspect above, and will not be repeated here.

[0185] For example, Fig.28 As shown, a first passivation layer 16 may be formed on the side of the first semiconductor layer 12 facing away from the semiconductor substrate 11. Fig.29 and Fig.30 As shown, the portion of the first passivation layer 16 located in the first conductive contact region 15 is irradiated with laser, so that the portion of the first passivation layer 16 located in the first conductive contact region 15 is removed. Fig.32 As shown, a first connection electrode 17 is formed in the first conductive contact area 15. In this case, compared with the prior art in which the semiconductor substrate 11 (or the semiconductor substrate 11 and the first semiconductor layer 12) is directly heated by a high-temperature laser, thereby completely removing the first passivation layer 16 located in the first conductive contact area 15 by generating a large thermal stress between the semiconductor substrate 11 and the first passivation layer 16 due to the temperature gradient, the manufacturing method provided in the embodiment of the present invention only removes part of the first passivation layer 16 located in the first conductive contact area 15 by the first laser, thereby reducing the degree of thermal damage to the semiconductor substrate 11 (or the semiconductor substrate 11 and the first semiconductor layer 12) located below the first passivation layer 16 in the laser irradiation area by the patterning process, improving the yield of the solar cell, and facilitating the manufactured solar cell to have good working performance.

[0186] In the actual manufacturing process, Fig.28 As shown, a chemical vapor deposition process or the like can be used to form a first passivation layer 16 on a side of the first semiconductor layer 12 away from the semiconductor substrate 11. Next, as shown in FIG. Fig.29 and Fig.30 As shown, the portion of the first passivation layer 16 located in the first conductive contact area 15 is irradiated with laser, so that the portion of the first passivation layer 16 located in the first conductive contact area 15 is removed. Specifically, after laser irradiation, the first passivation layer 16 located in the first conductive contact area 15 may be hollowed out; or, a blind hole or a recessed structure that is recessed into the first passivation layer 16 and does not penetrate the first passivation layer 16 may be formed. In this case, Fig.30 As shown, a corrosive liquid can be used to corrode the portion of the first passivation layer 16 located in the first conductive contact area 15, so that the recessed structure forms a hollow structure that penetrates the first passivation layer 16, ensuring that the first connection electrode 17 formed subsequently can be electrically connected to the first semiconductor layer 12 through the hollow setting of the first passivation layer 16. Alternatively, when the first passivation layer 16 located in the first conductive contact area 15 has been hollowed out after laser irradiation, a corrosive liquid can also be used to corrode the portion of the first passivation layer 16 located in the first conductive contact area 15, so as to increase the area of ​​the hollow area, increase the contact area between the first connection electrode 17 formed subsequently and the first semiconductor layer 12, and help reduce the contact resistance. Among them, the type of corrosive liquid can be determined according to the material of the first passivation layer 16, and is not specifically limited here. For example: in the case where the material of the first passivation layer 16 includes silicon nitride and / or silicon oxynitride, the corrosive liquid can be an acidic solution such as hydrofluoric acid, sulfuric acid or nitric acid. Then, as Fig.32 As shown, chemical plating, electroplating, screen printing, sputtering or evaporation processes can be used to form the first connection electrode 17 disposed in the first conductive contact area 15. In some examples, when chemical plating or electroplating is used to form the first connection electrode, the plating solution used for chemical plating or electroplating can replace the etching solution for treating the first passivation layer located in the first conductive contact area as described above. For example: if the above-mentioned etching solution is a hydrogen fluoride solution, then the plating solution used for chemical plating at this time contains hydrogen fluoride, and at this time, there is no need to use etching solution for additional treatment before forming the first connection electrode, or the time for additional treatment with etching solution before forming the first connection electrode can be shortened. Alternatively, etching solution treatment can also be used before chemical plating, and at this time, the chemical plating solution may not include a solution of the same type as the etching solution.

[0187] It should be noted that, if a surface passivation layer is formed on the side of the first semiconductor layer away from the semiconductor substrate before forming the first passivation layer, then after the laser is used to irradiate the portion of the first passivation layer located in the first conductive contact area, it is also necessary to form the first connection electrode in the first conductive contact area. Fig.31As shown, under the masking effect of the first passivation layer 16, the surface passivation layer 21 is selectively etched. Specifically, the selective etching of the surface passivation layer 21 can be completed while the portion of the first passivation layer 16 located in the first conductive contact area 15 is irradiated with a laser. Alternatively, after the portion of the first passivation layer 16 located in the first conductive contact area 15 is irradiated with a laser, the surface passivation layer 21 is selectively etched with an etching solution. The type of etching solution can be determined according to the material of the surface passivation layer, and is not specifically limited here.

[0188] Next, if Fig.33 As shown, after the first connection electrode 17 is formed in the first conductive contact area 15, the method for manufacturing a solar cell further includes the step of: using a process such as electroplating, sputtering or screen printing to form a plurality of conductive electrodes 20 arranged on the side of the first connection layer 13 away from the first semiconductor layer 12. The conductive electrode 20 is electrically connected to the first connection electrode 17 of at least one first conductive contact area 15. The material and width of the conductive electrode 20 can be referred to in the previous text and will not be repeated here.

[0189] In addition, when the manufactured solar cell further includes a second semiconductor layer of opposite conductivity type to the first semiconductor layer, the manufacturing method provided by the embodiment of the present invention further includes: forming the second semiconductor layer on the semiconductor substrate. The formation process of the second semiconductor layer can be determined according to the type of solar cell and the formation range of the second semiconductor layer on the semiconductor substrate, which is not specifically limited here.

[0190] Exemplarily, when the first semiconductor layer and the second semiconductor layer are arranged on the same side of the semiconductor substrate, a deposition process can be used to form a second semiconductor layer arranged in an entire layer on the surface of the semiconductor substrate exposed outside the first semiconductor layer and on the first semiconductor layer. Then, a deposition and etching process such as laser etching is used to form a mask layer on at least a portion of the second semiconductor layer covering the first semiconductor layer. Then, under the masking effect of the mask layer, a process such as wet etching is used to remove at least a portion of the second semiconductor layer covering the first semiconductor layer. Next, the mask layer is removed.

[0191] For example, when the first semiconductor layer and the second semiconductor layer are respectively disposed on opposite sides of the semiconductor substrate, the method for manufacturing the first semiconductor layer described above can be used to form the second semiconductor layer on the side of the semiconductor substrate away from the first semiconductor layer. The order of forming the first semiconductor layer and the second semiconductor layer can be set according to actual needs and is not specifically limited here.

[0192] After the second semiconductor layer is formed, a second connection electrode electrically connected to the second semiconductor layer may be formed according to the structure of the manufactured solar cell.

[0193] Exemplarily, in the case where the second semiconductor layer and the first semiconductor layer are arranged on the same side of the semiconductor substrate, if the manufactured solar cell includes the above-mentioned passivation connection layer, a process such as chemical vapor deposition can be used to form a passivation layer arranged on the side of the second semiconductor layer away from the semiconductor substrate. Then, a conductive window is opened in a partial area of ​​the passivation layer by using a process such as laser etching. Then, a second connection electrode electrically connected to the second semiconductor layer through the conductive window is formed by using a process such as screen printing. The materials of the passivation layer and the second connection electrode can be referred to in the previous text and will not be repeated here.

[0194] Alternatively, if the first connection layer in the manufactured solar cell also has the above-mentioned second conductive contact area, the first passivation layer arranged in the first conductive contact area can be processed by adopting the above-mentioned processing method for the first passivation layer arranged in the first conductive contact area, so that the first passivation layer is hollowed out in the second conductive contact area; then, a second connection electrode is formed in the second conductive contact area. The manufacturing method of the second connection electrode can refer to the manufacturing method of the first connection electrode described above, and will not be repeated here.

[0195] Exemplarily, when the first semiconductor layer and the second semiconductor layer are respectively arranged on opposite sides of the semiconductor substrate, when the manufactured solar cell also includes a passivation connection layer, the manufacturing method of the passivation connection layer can refer to the manufacturing method of the passivation connection layer when the second semiconductor layer and the first semiconductor layer are arranged on the same side of the semiconductor substrate described above, and will not be repeated here.

[0196] Alternatively, when the solar cell further includes a second connection layer, the method for manufacturing the second connection layer may refer to the method for manufacturing the first connection layer described above, and will not be described in detail herein.

[0197] The beneficial effects of the second aspect and its various implementations in the embodiments of the present invention can be analyzed with reference to the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0198] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0199] The embodiments of the present invention are described above. However, these embodiments are only for a clearer description and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A solar cell, characterized in that: include: Semiconductor substrate; A first semiconductor layer, disposed on the semiconductor substrate; A first connecting layer, disposed on a side of the first semiconductor layer away from the semiconductor substrate; Along a thickness direction perpendicular to the first connection layer, the first connection layer has a first passivation isolation region and a plurality of first conductive contact regions; A plurality of conductive electrodes are arranged on a side of the first connecting layer away from the first semiconductor layer; The first connection layer includes a first passivation layer disposed in the first passivation isolation region and a plurality of the first conductive contact regions, and a first connection electrode disposed in the first conductive contact region; the conductive electrode is electrically connected to the first connection electrode of at least one of the first conductive contact regions; The first passivation layer is hollowed out in the first conductive contact area, one end of the first connecting electrode along the thickness direction of the first passivation layer is electrically connected to the first semiconductor layer, and the other end of the first connecting electrode is exposed in the first passivation layer and electrically connected to the conductive electrode.

2. The solar cell according to claim 1, characterized in that The conductive electrode is electrically connected to the first connection electrodes of the first conductive contact regions.

3. The solar cell according to claim 1, characterized in that The first passivation layer comprises a nitrogen-containing passivation layer; And / or, the material of the first passivation layer includes at least one of silicon nitride and silicon oxynitride.

4. The solar cell according to claim 3, characterized in that: A nitrogen content of the first passivation layer in the first conductive contact region is less than a nitrogen content of the first passivation layer in the first passivation isolation region.

5. The solar cell according to claim 1, characterized in that: A portion of the first passivation layer located in the first conductive contact region has a plurality of holes penetrating the first passivation layer.

6. The solar cell according to claim 5, characterized in that: The maximum pore size of at least one of the holes is greater than or equal to 5 nm and less than or equal to 40 μm; And / or, in at least one of the first conductive contact regions, a ratio of a total area of ​​the holes in the first conductive contact region to an area of ​​the first conductive contact region is greater than or equal to 1% and less than or equal to 20%; And / or, in at least one of the holes, the size of the hole opening on the side away from the first semiconductor layer is smaller than the size of the hole bottom on the side close to the first semiconductor layer; And / or, at least one of the holes is cylindrical, bowl-shaped or gourd-shaped.

7. The solar cell according to claim 5, characterized in that: The first passivation layer has a texture structure on a side facing away from the first semiconductor layer; In the first conductive contact region, the holes are distributed at least at the ridges of the texture structure.

8. The solar cell according to claim 7, characterized in that: The holes are also distributed in the texture structure; in the first conductive contact area, the distribution density of the holes at the ridges of the texture structure is greater than the distribution density of the holes in the texture structure.

9. The solar cell according to claim 1, characterized in that: There is no glass body in the first conductive contact area of ​​the first connecting layer.

10. The solar cell according to claim 1, characterized in that The first passivation layer is randomly distributed in the first conductive contact area.

11. The solar cell according to claim 1 or 10, characterized in that: The thickness of the first passivation layer in the first conductive contact region is less than the thickness of the first passivation layer in the first passivation isolation region; And / or, the thickness of the first passivation layer in the first conductive contact region is less than or equal to 350 nm.

12. The solar cell according to claim 1, characterized in that The material of the first connecting electrode includes one or more of gold, silver, copper, aluminum, nickel, chromium, titanium and tin; And / or, the thickness of the first passivation layer is greater than or equal to 2 nm and less than or equal to 350 nm; And / or, the refractive index of the first passivation layer is greater than or equal to 1.5 and less than or equal to 3.

13. The solar cell according to claim 1, characterized in that A ratio between a width of the conductive electrode and a width of the first conductive contact region is greater than or equal to 0.6 and less than or equal to 2.

14. The solar cell according to claim 1, characterized in that The first passivation layer located in the first passivation isolation region includes an amorphous state, and the first passivation layer located in at least a portion of the first conductive contact region includes a crystalline state; And / or, a surface of the first passivation layer located in at least a portion of the first conductive contact region includes an oxide layer.

15. The solar cell according to claim 1, characterized in that The solar cell further includes a surface passivation layer disposed between the first semiconductor layer and the first connection layer; the first connection electrode penetrates through the surface passivation layer and is electrically connected to the first semiconductor layer.

16. The solar cell according to claim 1, characterized in that The solar cell further comprises a second semiconductor layer having a conductivity type opposite to that of the first semiconductor layer; Wherein, the first semiconductor layer and the second semiconductor layer are arranged on the same side of the semiconductor substrate, and at least a part of the first semiconductor layer is physically insulated from at least a part of the second semiconductor layer; the first connection layer further has a plurality of second conductive contact areas; the first passivation layer is further arranged in a plurality of second conductive contact areas; the first passivation layer is hollowed out in the second conductive contact areas; the first connection layer further comprises a second connection electrode arranged in the second conductive contact areas; one end of the second connection electrode along the thickness direction of the first passivation layer is electrically connected to the second semiconductor layer, and the other end of the second connection electrode is exposed from the first passivation layer; Or, the first semiconductor layer and the second semiconductor layer are respectively arranged on opposite sides of the semiconductor substrate; the solar cell also includes a second connection layer; along the thickness direction perpendicular to the second connection layer, the second connection layer has a second passivation isolation area and a plurality of second conductive contact areas; the second connection layer includes a second passivation layer arranged in the second passivation isolation area and the plurality of second conductive contact areas, and a second connection electrode arranged in the second conductive contact area; the second passivation layer is hollowed out in the second conductive contact area, one end of the second connection electrode along the thickness direction of the second passivation layer is electrically connected to the second semiconductor layer, and the other end of the second connection electrode is exposed in the second passivation layer.

17. The solar cell according to claim 16, characterized in that: The area of ​​the first conductive contact region is different from the area of ​​the second conductive contact region; and / or, the total area of ​​all the first conductive contact regions in the first connecting layer is different from the total area of ​​all the second conductive contact regions in the first connecting layer; and / or, the total area of ​​all the first conductive contact regions in the first connecting layer is different from the total area of ​​all the second conductive contact regions in the second connecting layer; and / or, the area of ​​the hollow region of the first conductive contact region is different from the area of ​​the hollow region of the second conductive contact region; and / or, the total area of ​​the hollowed-out regions of all the first conductive contact regions in the first connecting layer is different from the total area of ​​the hollowed-out regions of all the second conductive contact regions in the first connecting layer; And / or, the total area of ​​the hollowed-out regions of all the first conductive contact regions in the first connecting layer is different from the total area of ​​the hollowed-out regions of all the second conductive contact regions in the second connecting layer.

18. A method for manufacturing a solar cell, characterized in that: include: Providing a semiconductor substrate; forming a first semiconductor layer on the semiconductor substrate; forming a first connecting layer on a side of the first semiconductor layer facing away from the semiconductor substrate; The first connection layer has a first passivation isolation region and a plurality of first conductive contact regions along a thickness direction perpendicular to the first connection layer, wherein the first connection layer includes a first passivation layer disposed in the first passivation isolation region and the plurality of first conductive contact regions, and a first connection electrode disposed in the first conductive contact region; the first passivation layer is hollowed out in the first conductive contact region, one end of the first connection electrode along the thickness direction of the first passivation layer is electrically connected to the first semiconductor layer, and the other end of the first connection electrode is exposed from the first passivation layer; A plurality of conductive electrodes are formed on a side of the first connecting layer facing away from the first semiconductor layer; the conductive electrodes are electrically connected to the first connecting electrode of at least one of the first conductive contact regions.

19. The method for manufacturing a solar cell according to claim 18, characterized in that: The forming of a first connection layer on a side of the first semiconductor layer away from the semiconductor substrate comprises: forming a first passivation layer on a side of the first semiconductor layer facing away from the semiconductor substrate; irradiating the portion of the first passivation layer located in the first conductive contact region with a laser, so that the portion of the first passivation layer located in the first conductive contact region is removed; The first connecting electrode is formed in the first conductive contact region.

20. The method for manufacturing a solar cell according to claim 19, characterized in that: After irradiating the portion of the first passivation layer located in the first conductive contact region with laser, and before forming the first connecting electrode in the first conductive contact region, the method for manufacturing a solar cell further includes: The portion of the first passivation layer located in the first conductive contact area is corroded by using an etching solution.

21. The method for manufacturing a solar cell according to claim 19, characterized in that: The forming of the first passivation layer on the side of the first semiconductor layer away from the semiconductor substrate comprises: sequentially forming a stacked surface passivation layer and a first passivation layer on the side of the first semiconductor layer away from the semiconductor substrate; After the laser is used to irradiate the portion of the first passivation layer located in the first conductive contact area and before the first connecting electrode is formed in the first conductive contact area, the method for manufacturing a solar cell further includes: selectively etching the surface passivation layer under the masking effect of the first passivation layer.

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