Method for manufacturing a solar cell and solar cell

Abstract

An embodiment of the present application provides a method for manufacturing a solar cell and a solar cell. The method for manufacturing a solar cell includes: providing a battery substrate, where the battery substrate includes a substrate and a passivation layer provided on the surface of the substrate; applying a metal ion solution on the surface of the passivation layer of the battery substrate, and irradiating one side of the battery substrate where the metal ion solution is applied with a laser to form grooves in the passivation layer. At the same time, the metal ion solution undergoes a chemical reaction under the action of the laser to generate metal, and the metal is deposited at the grooves of the passivation layer to form an electrode, and an ohmic contact is formed between the electrode and the substrate, thereby obtaining a solar cell. The method for manufacturing a solar cell according to the embodiment of the present application realizes the grooving of the passivation layer and the preparation of the electrode simultaneously by one laser processing step, thereby saving one production process and reducing the production cost of the solar cell.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and particularly relates to a manufacturing method of a solar cell and a solar cell. Background Art

[0002] Solar energy is a clean and renewable energy source, which is inexhaustible and is the most likely energy source to replace conventional fossil fuels. Photovoltaic power generation is one of the main ways to utilize solar energy at present and has become an emerging industry that has attracted widespread attention and key development in various countries around the world.

[0003] There are a large number of metal grid lines (electrodes) for collecting current on the surface of a solar cell. Before preparing the metal grid lines, laser is usually used to groove the passivation layer on the surface of the solar cell to form a grid line pattern, and then methods such as electroplating are used to form metal grid lines in electrical contact with the silicon substrate in the grooves of the passivation layer. However, due to the large number of process steps, and each process step will generate corresponding production costs, resulting in a relatively high production cost of the solar cell. Summary of the Invention

[0004] An embodiment of the present application provides a manufacturing method of a solar cell and a solar cell. The manufacturing method of the solar cell simultaneously realizes grooving of the passivation layer and preparation of the electrode by one laser processing step, thereby saving one production process and reducing the production cost of the solar cell.

[0005] In a first aspect, an embodiment of the present application provides a manufacturing method of a solar cell, including:

[0006] Providing a battery substrate, where the battery substrate includes a substrate and a passivation layer provided on the surface of the substrate;

[0007] Applying a metal ion solution on the surface of the passivation layer of the battery substrate, and irradiating one side of the battery substrate on which the metal ion solution is applied with laser, forming grooves in the passivation layer. At the same time, the metal ion solution undergoes a chemical reaction under the action of the laser to generate metal, and the metal is deposited at the grooves of the passivation layer to form an electrode, and an ohmic contact is formed between the electrode and the substrate, obtaining a solar cell.

[0008] In some embodiments, during the process of irradiating the battery substrate with laser, the metal ion solution is continuously and uninterruptedly applied above the battery substrate to form a liquid film layer on the surface of the battery substrate, and the liquid film layer always maintains a continuously flowing state.

[0009] In some embodiments, the site on the battery substrate irradiated by the laser is the first site, and the site on the battery substrate to which the metal ion solution is applied is the second site. During the process of irradiating the battery substrate with the laser, both the first site and the second site move relative to the battery substrate, and during the movement, the first site and the second site maintain at least partial overlap.

[0010] In some embodiments, the manufacturing method of the solar cell is implemented by a laser-induced metal deposition device. The laser-induced metal deposition device includes a solution tank, a processing platform, a transfer pipeline, a pump device, a nozzle, and a laser emitting device. The solution tank is used to contain the metal ion solution, the processing platform is used to carry the battery substrate, the transfer pipeline is used to transfer the metal ion solution in the solution tank to the nozzle, the pump device is used to pump the metal ion solution into the transfer pipeline, the nozzle is used to spray the metal ion solution onto the battery substrate, and the laser emitting device is used to emit laser light towards the battery substrate.

[0011] In some embodiments, the nozzle is provided with a through hole, and the laser light emitted by the laser emitting device passes through the through hole and irradiates onto the battery substrate. An annular fluid channel is provided inside the nozzle, and the annular fluid channel surrounds the through hole. After the metal ion solution flows out through the annular fluid channel, it converges together to form a liquid column before reaching the battery substrate or when it reaches the battery substrate. The site on the battery substrate where the liquid column is applied and the site on the battery substrate where the laser is applied at least partially overlap;

[0012] During the process of irradiating the battery substrate with the laser, both the laser emitting device and the nozzle move relative to the battery substrate, and during the movement, the laser emitting device and the nozzle remain relatively stationary.

[0013] In some embodiments, the laser is a pulsed laser, and the pulsed laser includes at least one of nanosecond laser, picosecond laser, and femtosecond laser; the laser beam includes at least one of Gaussian beam and flat-top beam;

[0014] The light spot of the laser beam focused on the battery substrate is circular, and the diameter of the light spot is 5 μm to 120 μm; or, the light spot of the laser beam focused on the battery substrate is rectangular, and the side length of the light spot is 5 μm to 120 μm.

[0015] In some embodiments, the metal ions in the metal ion solution include at least one of copper ions, nickel ions, and silver ions.

[0016] In some embodiments, the metal ion solution includes a metal salt, a reducing agent, a complexing agent, and water. Among them, the concentration of the metal salt is 3 g / L to 10 g / L, the concentration of the reducing agent is 10 g / L to 30 g / L, and the concentration of the complexing agent is 1 g / L to 10 g / L.

[0017] In some embodiments, the metal salt includes at least one of copper sulfate, copper tartrate, copper nitrate, nickel sulfate, nickel acetate, and silver ammonia;

[0018] The reducing agent includes at least one of formaldehyde, hypophosphite, borohydride, hydrazine, and glucose;

[0019] The complexing agent includes at least one of sodium citrate, sodium tartrate, and malic acid.

[0020] In a second aspect, an embodiment of the present application provides a solar cell, which is prepared by using the manufacturing method of the solar cell as described above.

[0021] In the manufacturing method of the solar cell provided by the embodiment of the present application, by applying a metal ion solution on the surface of the passivation layer of the cell substrate, when laser irradiates one side of the cell substrate where the metal ion solution is applied, not only can grooves be formed on the passivation layer, but also, after grooving, the metal ion solution can undergo a chemical reaction under the action of the laser to generate metal, and the metal is deposited at the grooves of the passivation layer to form an electrode. That is to say, the embodiment of the present application realizes both the grooving of the passivation layer and the preparation of the electrode by one laser processing step, thereby saving one production process, reducing the production cost of the solar cell, and, in the process of laser etching the passivation layer, since the metal ion solution on the surface of the passivation layer can absorb a part of the heat converted by the laser, the temperature of the area on the cell substrate irradiated by the laser can be reduced, and further, the thermal damage to the substrate caused by the laser can be reduced or eliminated. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments.

[0023] Figure 1 It is a flowchart of the manufacturing method of the solar cell provided by the embodiment of the present application.

[0024] Figure 2 It is a schematic structural diagram of the cell substrate provided by the embodiment of the present application.

[0025] Figure 3 It is a schematic structural diagram of the laser-induced metal deposition equipment provided by the embodiment of the present application.

[0026] Figure 4Schematic diagram of the structure of the solar cell prepared in the embodiment of the present application. Detailed implementation manners

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0028] Please refer to Figure 1 , Figure 1 which is a flowchart of the manufacturing method of the solar cell provided in the embodiment of the present application. The embodiment of the present application provides a manufacturing method of a solar cell, including:

[0029] S100, please refer to Figure 2 , and provide a battery substrate 10, where the battery substrate 10 includes a substrate 11 and a passivation layer 12 provided on the surface of the substrate 11.

[0030] Exemplarily, the material of the substrate 11 may include silicon, such as crystalline silicon (monocrystalline silicon or polycrystalline silicon) or amorphous silicon. Exemplarily, the substrate 11 is doped with an N-type doping element or a P-type doping element. Among them, the N-type doping element is usually a group V element, such as phosphorus, arsenic or antimony, etc., and the P-type doping element may be elements such as boron, aluminum or gallium.

[0031] Exemplarily, the material of the passivation layer 12 includes silicon nitride (SiN x ).

[0032] In some embodiments, a passivation layer 12 is provided on one side (front or back) of the substrate 11, and the other side is not provided with a passivation layer 12 (as shown in Figure 2 ), and in other embodiments, passivation layers 12 are provided on both sides (front and back) of the substrate 11.

[0033] S100, please refer to Figure 3 , apply a metal ion solution 41 on the surface of the passivation layer 12 of the battery substrate 10, and irradiate the side of the battery substrate 10 where the metal ion solution 41 is applied with a laser 91 to form a groove 121 on the passivation layer 12. At the same time, the metal ion solution 41 undergoes a chemical reaction under the action of the laser 91 to generate metal, and the metal is deposited at the groove 121 of the passivation layer 12 to form an electrode 30. An ohmic contact is formed between the electrode 30 and the substrate 11 to obtain a solar cell 100.

[0034] It can be understood that when the laser 91 irradiates the metal ion solution 41, the metal ion solution 41 will absorb a part of the energy of the laser 91 to generate heat. The metal ion solution 41 undergoes a photochemical reaction and a thermal chemical reaction under the action of the laser 91, thereby converting metal ions into metal atoms.

[0035] Exemplarily, during the process of irradiating the battery substrate 10 with the laser 91, the metal ion solution 41 is continuously and uninterruptedly applied above the battery substrate 10 to form a liquid film layer 42 on the surface of the battery substrate 10, and the liquid film layer 42 always maintains a continuously flowing state.

[0036] It should be noted that during the process of irradiating the battery substrate 10 with the laser 91, in order to form the pattern of the grid line (electrode 30), the laser 91 needs to be in a moving state, so that linear grooves 121 and linear electrodes 30 can be formed on the passivation layer 12. It can be understood that if the liquid film layer 42 on the surface of the battery substrate 10 is formed by a single application, then during the irradiation process of the laser 91, as time goes by, the metal ions in the liquid film layer 42 will continuously decrease. Therefore, when the laser 91 moves relative to the battery substrate 10 at a constant speed, there will be a significant difference in the thickness of the metal layer formed in the early stage of the laser 91 irradiation process (i.e., the front end of the electrode 30) and the metal layer formed in the later stage of the laser 91 irradiation process (i.e., the rear end of the electrode 30), resulting in uneven thickness in different regions of the electrode 30, which will further affect the electrical performance of the solar cell 100. In the embodiment of the present application, by continuously and uninterruptedly applying the metal ion solution 41 above the battery substrate 10, the liquid film layer 42 always maintains a continuously flowing state, that is to say, the liquid film layer 42 keeps changing, and the liquid film layer 42 is always formed by the newly flowing-in metal ion solution 41, so that the metal ion concentration in the liquid film layer 42 can be maintained within a relatively stable range (or maintained at a constant value). Therefore, when the laser 91 moves relative to the battery substrate 10 at a constant speed, there will be no significant difference in the thickness of the metal layer formed in the early stage of the laser 91 irradiation process and the metal layer formed in the later stage of the laser 91 irradiation process, and the thickness of different regions of the electrode 30 remains uniform, thereby improving the electrical performance of the solar cell 100.

[0037] Exemplarily, the thickness of the liquid film layer 42 can be 0.2 mm to 0.8 mm, such as 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, etc. In some embodiments, the thickness of the liquid film layer 42 is 0.5 mm.

[0038] Exemplarily, the site on the battery substrate 10 irradiated by the laser 91 is the first site, and the site on the battery substrate 10 where the metal ion solution 41 is applied is the second site. During the process of irradiating the battery substrate 10 with the laser 91, both the first site and the second site move relative to the battery substrate 10, and the first site and the second site remain at least partially overlapped.

[0039] It should be noted that by setting the site (the first site) on the battery substrate 10 irradiated by the laser 91 and the site (the second site) on the battery substrate 10 where the metal ion solution 41 is applied to be at least partially overlapped, it can be ensured that the position irradiated by the laser 91 on the liquid film layer 42 is always flowing with fresh metal ion solution 41, that is to say, it can be ensured that the concentration of metal ions at the position irradiated by the laser 91 remains unchanged. Therefore, when the laser 91 moves relative to the battery substrate 10 at a constant speed, along the trajectory of the movement of the laser 91, the thickness of the metal layer formed on the battery substrate 10 can always be kept uniform, so that the thickness of different regions of the electrode can be kept uniform, thereby improving the electrical performance of the solar cell 100.

[0040] In some embodiments, the first site and the second site may completely overlap, that is, the sizes and shapes of the first site and the second site are exactly the same.

[0041] Please refer to Figure 3 , Figure 3 which is a schematic structural diagram of the laser-induced metal deposition device 200 provided by the embodiment of the present application. The manufacturing method of the solar cell can be realized by using the laser-induced metal deposition device 200. The laser-induced metal deposition device 200 includes a solution tank 40, a processing platform 50, a transfer pipeline 60, a pump device 70, a nozzle 80, and a laser emitting device 90. The solution tank 40 is used to hold the metal ion solution 41, the processing platform 50 is used to carry the battery substrate 10, the transfer pipeline 60 is used to transfer the metal ion solution 41 in the solution tank 40 to the nozzle 80, the pump device 70 is used to pump the metal ion solution 41 into the transfer pipeline 60, the nozzle 80 is used to spray the metal ion solution 41 onto the battery substrate 10, and the laser emitting device 90 is used to emit the laser 91 towards the battery substrate 10.

[0042] Please combine Figure 3 ,a through hole 81 is provided on the nozzle 80, and the laser 91 emitted by the laser emitting device 90 passes through the through hole 81 and irradiates onto the battery substrate 10. An annular fluid channel 82 is provided inside the nozzle 80, and the annular fluid channel 82 is arranged around the through hole 81. After the metal ion solution 41 flows out through the annular fluid channel 82, it converges to form a liquid column before reaching the battery substrate 10 or when reaching the battery substrate 10, and the site where the liquid column is applied to the battery substrate 10 and the site where the laser 91 is applied to the battery substrate 10 are at least partially overlapped;

[0043] During the process of irradiating the battery substrate 10 with a laser, both the laser emitting device 90 and the nozzle 80 move relative to the battery substrate 10, and the laser emitting device 90 and the nozzle 80 remain relatively stationary with respect to each other.

[0044] Please refer to Figure 3 , the processing platform 50 is arranged corresponding to the solution tank 40, and the processing platform 50 is arranged above the liquid level of the metal ion solution 41. At this time, the metal ion solution 41 applied to the battery substrate 10 will continuously overflow into the solution tank 40, thereby realizing the recycling of the metal ion solution 41. By recycling the metal ion solution 41, the production cost of the solar cell 100 can be reduced, and the generation of waste liquid that pollutes the environment can be avoided. It can be understood that since the amount of metal ions required to prepare the electrodes on a single solar cell 100 is small, which is negligible compared to the amount of metal ions in the metal ion solution 41 in the entire solution tank 40, therefore, during the production process of a single solar cell 100, the concentration of metal ions in the metal ion solution 41 in the solution tank 40 will not change significantly. Therefore, during the production process of a single or several (less than 10) solar cells 100, the metal ion solution 41 in the solution tank 40 does not need to be replaced. When the production of solar cells 100 exceeds 10, metal salts can be added to the solution tank 40 to supplement metal ions, or the metal ion solution 41 can be directly replaced with a new one.

[0045] Exemplarily, the processing platform 50 can be used to carry multiple (two or more) battery substrates 10. The processing platform 50 has a rotating function. After a solar cell 100 is prepared, the processed solar cell 100 can be moved away from the processing station by rotating the processing platform 50, and the battery substrate 10 to be processed can be rotated to the processing station.

[0046] Please refer to Figure 3 , the transfer pipeline 60 has an inlet end and an outlet end. The inlet end is used to suck the metal ion solution 41 in the solution tank 40, and the outlet end is connected to the nozzle 80. The pump device 70 can be arranged at any position on the transfer pipeline 60 between the inlet end and the outlet end (as shown in Figure 3 ), or the pump device 70 can be arranged in the solution tank 40 and the pump device 70 is connected to the inlet end of the transfer pipeline 60 (not shown). Exemplarily, the pump device 70 can be a hydraulic pump.

[0047] Exemplarily, the laser 91 is a pulsed laser 91, and the pulsed laser 91 includes at least one of a nanosecond laser 91, a picosecond laser 91, and a femtosecond laser 91; the laser beam of the laser 91 includes at least one of a Gaussian beam and a flat-top beam.

[0048] Exemplarily, the light spot formed by the beam of laser 91 focused on the battery substrate 10 can be circular, and the diameter of the light spot is 5 μm to 120 μm (such as 5 μm, 10 μm, 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, etc.).

[0049] Exemplarily, the light spot formed by the beam of laser 91 focused on the battery substrate 10 can also be rectangular (rectangle or square), and the side length (length or width) of the light spot is 5 μm to 120 μm (such as 5 μm, 10 μm, 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, etc.).

[0050] Exemplarily, the beam of laser 91 can include at least one of a Gaussian beam and a flat-top beam.

[0051] Exemplarily, the metal ions in the metal ion solution 41 include at least one of copper ions, nickel ions, and silver ions.

[0052] Exemplarily, the metal ion solution 41 includes a metal salt, a reducing agent, a complexing agent, and water. Among them, the concentration of the metal salt is 3 g / L to 10 g / L (such as 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, etc.), the concentration of the reducing agent is 10 g / L to 30 g / L (such as 10 g / L, 12 g / L, 15 g / L, 18 g / L, 20 g / L, 22 g / L, 25 g / L, 28 g / L, 30 g / L, etc.), and the concentration of the complexing agent is 1 g / L to 10 g / L (such as 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, etc.).

[0053] Exemplarily, the metal salt can include at least one of copper sulfate, copper tartrate, copper nitrate, nickel sulfate, nickel acetate, and silver ammonia.

[0054] Exemplarily, the reducing agent can include at least one of formaldehyde, hypophosphite, borohydrides (such as sodium borohydride, potassium borohydride, etc.), hydrazine, and glucose.

[0055] Exemplarily, the complexing agent can include at least one of sodium citrate, sodium tartrate, and malic acid.

[0056] In some embodiments, the metal ion solution 41 is a copper ion solution. The copper ion solution includes a copper salt, a reducing agent, a complexing agent, and water. Among them, the copper salt is copper sulfate, copper tartrate, or copper nitrate, and the reducing agent is formaldehyde.

[0057] In some embodiments, the metal ion solution 41 is a nickel ion solution, which includes a nickel salt, a reducing agent, a chelating agent and water, wherein the nickel salt is nickel sulfate or nickel acetate, and the reducing agent is at least one of hypophosphite, borohydride and hydrazine.

[0058] In some embodiments, the metal ion solution 41 is a silver ion solution, which includes a silver salt, a reducing agent, a complexing agent and water, wherein the silver salt is silver ammonia and the reducing agent is glucose.

[0059] In summary, the method for manufacturing a solar cell provided in the embodiment of the present application applies a metal ion solution 41 to the surface of the passivation layer 12 of the battery substrate 10. When the laser 91 is used to irradiate the side of the battery substrate 10 to which the metal ion solution 41 is applied, not only can a groove 121 be formed on the passivation layer 12, but also, after grooving, the metal ion solution 41 can undergo a chemical reaction under the action of the laser 91 to generate a metal, and the metal is deposited in the groove 121 of the passivation layer 12 to form an electrode. That is to say, the embodiment of the present application simultaneously realizes the grooving of the passivation layer 12 and the preparation of the electrode by adopting a laser 91 processing step, thereby saving a production step and reducing the production cost of the solar cell 100. Moreover, in the process of laser etching the passivation layer 12, since the metal ion solution 41 on the surface of the passivation layer 12 can absorb a part of the heat converted by the laser, the temperature of the area irradiated by the laser 91 on the battery substrate 10 can be reduced, thereby reducing or eliminating the thermal damage caused by the laser 91 to the substrate 11.

[0060] In the prior art, the grooves of the passivation layer and the preparation of the gate are usually completed in two processes, and the passivation layer on the surface of the substrate is usually grooved by laser. It can be understood that in the process of laser etching the passivation layer (silicon nitride film), the energy in the laser irradiation area is concentrated and the temperature rises. Therefore, the heat generated by the laser can not only ablate the passivation layer to form grooves, but also damage the PN junction in the substrate (silicon wafer) to form a large number of defects inside the substrate, thereby reducing the efficiency of the solar cell 100. The present application applies a metal ion solution to the surface of the passivation layer of the battery substrate. Therefore, in the process of laser etching the passivation layer, the metal ion solution on the surface of the passivation layer can absorb a part of the heat converted by the laser, thereby reducing the temperature of the laser irradiated area on the battery substrate, thereby reducing or eliminating the thermal damage caused by the laser to the substrate; in addition, when the metal ion solution on the surface of the passivation layer remains in a flowing state, the metal ion solution flowing away from the surface of the passivation layer will also take away a part of the heat, thereby further reducing the temperature of the laser irradiated area on the battery substrate, and avoiding the substrate being burned by the energy of the laser to cause defects.

[0061] See also Figure 4 , Figure 4Schematic structural diagram of the solar cell prepared in the embodiment of the present application. The present application also provides a solar cell, which is prepared by using the manufacturing method of the solar cell in any of the above embodiments.

[0062] Please refer to Figure 4 , the solar cell 100 may include a substrate 11, a passivation layer 12 and an electrode 30 disposed on the substrate 11. Among them, a groove 121 is provided on the passivation layer 12, the electrode 30 is disposed in the groove 121, and an ohmic contact is formed between the electrode 30 and the substrate 11.

[0063] Exemplarily, the material of the substrate 11 includes silicon.

[0064] Exemplarily, the material of the passivation layer 12 includes silicon nitride (SiN x ).

[0065] Exemplarily, the material of the electrode 30 may be a metal, and the metal may include at least one of nickel, copper, and silver; in some embodiments, the electrode 30 may include a nickel layer, a copper layer, and a silver layer stacked in sequence on the silicon wafer.

[0066] Exemplarily, the thickness of the passivation layer 12 may be 80 nm to 120 nm, such as 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, etc. In some embodiments, the thickness of the passivation layer 12 is 100 nm.

[0067] Exemplarily, the thickness of the electrode 30 may be 10 μm to 20 μm, such as 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc. In some embodiments, the thickness of the electrode 30 is 15 μm.

[0068] Exemplarily, the material of the electrode 30 may include at least one of copper, nickel, and silver.

[0069] In some embodiments, a passivation layer 12 is provided on one side (front or back) of the substrate 11, and the other side is not provided with a passivation layer 12 (as Figure 2 shown); in other embodiments, passivation layers 12 are provided on both sides (front and back) of the substrate 11. Exemplarily, when passivation layers 12 are provided on both sides of the substrate 11, grooves 121 may be provided on both sides of the passivation layer 12, and electrodes 30 are provided in the grooves 121 on both sides.

[0070] The method for manufacturing a solar cell and the solar cell provided in the embodiments of the present application have been introduced in detail above. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only for helping to understand the present application. At the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for manufacturing a solar cell, characterized in that, comprising: providing a battery substrate, the battery substrate including a substrate and a passivation layer provided on the surface of the substrate; applying a metal ion solution on the surface of the passivation layer of the battery substrate, irradiating one side of the battery substrate on which the metal ion solution is applied with a laser, forming a groove in the passivation layer, and at the same time, the metal ion solution undergoes a chemical reaction under the action of the laser to generate a metal, and the metal is deposited at the groove of the passivation layer to form an electrode, and an ohmic contact is formed between the electrode and the substrate to obtain a solar cell; during the process of irradiating the battery substrate with a laser, continuously and uninterruptedly applying the metal ion solution above the battery substrate to form a liquid film layer on the surface of the battery substrate, and the liquid film layer always maintains a continuously flowing state so that the thickness of the liquid film layer is 0.2 mm to 0.8 mm.

2. The method for manufacturing a solar cell according to claim 1, characterized in that, the site where the laser irradiates on the battery substrate is the first site, and the site where the metal ion solution is applied to the battery substrate is the second site. During the process of irradiating the battery substrate with a laser, both the first site and the second site move relative to the battery substrate, and during the movement, at least part of the first site and the second site overlap.

3. The method for manufacturing a solar cell according to claim 1, characterized in that, the method for manufacturing the solar cell is realized by a laser-induced metal deposition device. The laser-induced metal deposition device includes a solution tank, a processing platform, a transmission pipeline, a pump device, a nozzle, and a laser emission device. The solution tank is used to hold the metal ion solution, the processing platform is used to carry the battery substrate, the transmission pipeline is used to transport the metal ion solution in the solution tank to the nozzle, the pump device is used to pump the metal ion solution into the transmission pipeline, the nozzle is used to spray the metal ion solution onto the battery substrate, and the laser emission device is used to emit a laser towards the battery substrate.

4. The method for manufacturing a solar cell according to claim 3, characterized in that, the nozzle is provided with a through hole, and the laser emitted by the laser emission device passes through the through hole and irradiates onto the battery substrate. An annular fluid channel is provided inside the nozzle, and the annular fluid channel surrounds the through hole. After the metal ion solution flows out through the annular fluid channel, it converges together to form a liquid column before reaching the battery substrate or when it reaches the battery substrate, and at least part of the site where the liquid column is applied to the battery substrate overlaps with the site where the laser is applied to the battery substrate; during the process of irradiating the battery substrate with a laser, both the laser emission device and the nozzle move relative to the battery substrate, and during the movement, the laser emission device and the nozzle remain relatively stationary.

5. The method for manufacturing a solar cell according to claim 1, It is characterized in that the laser is a pulsed laser, and the pulsed laser includes at least one of nanosecond laser, picosecond laser and femtosecond laser; the beam of the laser includes at least one of Gaussian beam and flat-top beam; the spot formed by focusing the beam of the laser on the battery substrate is circular, and the diameter of the spot is 5μm to 120μm; or, the spot formed by focusing the beam of the laser on the battery substrate is rectangular, and the side length of the spot is 5μm to 120μm.

6. The method for manufacturing a solar cell according to claim 1, It is characterized in that the metal ions in the metal ion solution include at least one of copper ions, nickel ions and silver ions.

7. The method for manufacturing a solar cell according to claim 1, It is characterized in that the metal ion solution includes metal salt, reducing agent, complexing agent and water, wherein the concentration of the metal salt is 3g / L to 10g / L, the concentration of the reducing agent is 10g / L to 30g / L, and the concentration of the complexing agent is 1g / L to 10g / L.

8. The method for manufacturing a solar cell according to claim 7, It is characterized in that the metal salt includes at least one of copper sulfate, copper tartrate, copper nitrate, nickel sulfate, nickel acetate and silver ammonia; the reducing agent includes at least one of formaldehyde, hypophosphite, borohydride, hydrazine and glucose; the complexing agent includes at least one of sodium citrate, sodium tartrate and malic acid.

9. A solar cell, It is characterized in that it is prepared by using the method for manufacturing a solar cell according to any one of claims 1-8.

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