Battery piece processing method, battery piece and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field. The embodiment of the invention provides a processing method of a battery piece, the battery piece and a photovoltaic module. The processing method of the battery piece comprises the following steps: texturing the first surface and / or the second surface of the substrate, arranging doped slurry on the surface of the first region and curing, and forming a doped region in the first region. And passivating the substrate. And preparing an electrode at a corresponding position of the doped region. According to the processing method provided by the embodiment of the invention, the wet etching steps are fewer, the process is simple, the cost is lower, meanwhile, the auger recombination of the processed cell is lower, the open-circuit voltage is higher, the conversion efficiency is higher, and the overall performance of the cell is better.

Description

Technical Field

[0001] This application relates to the photovoltaic field, and more particularly to a method for processing solar cells, solar cells, and photovoltaic modules. Background Technology

[0002] With technological advancements, photovoltaic (PV) modules are becoming increasingly widely used. PV modules consist of solar cells, which absorb light energy and convert it into electrical energy. Therefore, the processing technology and performance of the solar cells are crucial factors affecting the cost and performance of PV modules. Summary of the Invention

[0003] This application provides a method for processing solar cells, solar cells, and photovoltaic modules, which simplifies the processing technology of solar cells and improves the performance of solar cells.

[0004] This application provides a method for processing a battery cell. The first surface and / or second surface of the battery cell substrate includes a first region and a second region, with a second region disposed between adjacent first regions. The method for processing the battery cell includes: Texturing the first surface having the first region and / or the second surface having the first region; A doped slurry is applied to the surface of the first region and cured, thereby forming a doped region in the first region; The substrate is passivated; Electrodes are fabricated at the corresponding positions in the doped region.

[0005] In one possible implementation, the steps of applying and curing a doped slurry in the first region to form a doped region include: The doping slurry is applied to the surface of the first region and cured, thereby directly doping the first region to form the doped region.

[0006] In one possible implementation, the step of depositing and curing the doping paste on the surface of the first region, and directly doping the first region to form the doped region includes: The doping paste is applied to the surface of the first region of the first surface and cured, thereby directly doping the first region of the first surface to form a first doped region; Clean the substrate; The doping slurry is applied to the surface of the first region of the second surface and cured, thereby directly doping the first region of the second surface to form a second doped region.

[0007] In one possible implementation, the step of depositing and curing the doping paste on the surface of the first region, and directly doping the first region to form the doped region includes: The first region is directly doped by at least one of the following methods: high-temperature heat treatment, high-energy particle irradiation, and laser annealing activation.

[0008] In one possible implementation, the high-temperature heat treatment conditions are as follows: a treatment temperature of 750°C to 1100°C, an inert gas atmosphere, a treatment pressure of 10 mbar to atmospheric pressure, and a treatment time of 5 to 60 minutes; followed by a treatment temperature of 750°C to 1100°C, an oxygen atmosphere, a treatment pressure of 10 mbar to atmospheric pressure, and a treatment time of 10 to 180 minutes. The conditions for high-energy particle irradiation are as follows: ionization of inert gas is used to accelerate the particles to bombard the material for high-energy particle irradiation; particle energy is 10 keV to 1 MeV; incident angle is 90 degrees; and vacuum level is 10. -4 Pa to 10 -7 Pa; The conditions for laser annealing activation are as follows: infrared laser is used, with a laser wavelength of 1024nm, laser power of 100W to 2000W, spot size of 30um to 900um, spot stacking scanning, and scanning speed of 0.2m / s to 8m / s.

[0009] In one possible implementation, the step of applying a doped paste to the surface of the first region and curing it to form a doped region in the first region includes: The doping paste is disposed on the surface of the first region, and the doping paste is diffused into the first region to form a diffusion region; the diffusion region is activated to form the doped region.

[0010] In one possible implementation, the doping paste is disposed on the surface of the first region, and the doping paste diffuses into the first region to form a diffusion region. The step of activating the diffusion region to form the doped region includes: The doping paste is applied to the surface of the first region of the first surface and cured, so that the doping paste diffuses to the first region of the first surface to form a first diffusion region, and the first diffusion region is activated to form a first doped region. Clean the substrate; The doping paste is applied to the surface of the first region of the second surface and cured, so that the doping paste diffuses to the first region of the second surface to form a second diffusion region, and the second diffusion region is activated to form a second doped region.

[0011] In one possible implementation, the doped paste is disposed on the surface of the first region, and the doped paste diffuses into the first region to form a diffusion region. The step of activating the diffusion region includes: The doped slurry is diffused into the first region to form the diffusion region by at least one of the following methods: high-temperature heat treatment, high-energy particle irradiation, and laser annealing activation.

[0012] In one possible implementation, the conditions for high-temperature heat treatment are: treatment temperature of 750°C to 1100°C, treatment time of 5 minutes to 30 minutes, inert gas atmosphere, and treatment pressure of 10 mbar to atmospheric pressure. The conditions for high-energy particle irradiation are as follows: ionization of inert gas is used to accelerate the particles to bombard the material for high-energy particle irradiation; particle energy ranges from 10 keV to 700 keV; incident angle is 90 degrees; and vacuum level is 10. -4 Pa to 10 -7 Pa; The conditions for laser annealing activation are as follows: infrared laser with a wavelength of 1024nm, laser power of 100W to 1000W, spot size of 30um to 900um, spot stacking scanning, and scanning speed of 0.2m / s to 8m / s.

[0013] In one possible implementation, the doped paste is disposed on the surface of the first region, and the doped paste diffuses into the first region to form a diffusion region. The step of activating the diffusion region includes: The diffusion region is activated by high-temperature heat treatment; The conditions for high-temperature heat treatment are: treatment temperature 750℃ to 1100℃, treatment time 10 minutes to 180 minutes, oxygen atmosphere, and treatment pressure 10 mbar to atmospheric pressure.

[0014] In one possible implementation, the step of applying a doped paste to the surface of the first region and curing it to form a doped region in the first region includes: The doping type of the first region on the first surface is different from the doping type of the first region on the second surface.

[0015] In one possible implementation, the step of passivating the substrate includes: Clean the substrate to remove residual slurry and oxide layer from the surface of the substrate; A passivation layer is formed on the surface of the substrate.

[0016] In one possible implementation, the step of fabricating an electrode at the corresponding location of the doped region includes: The electrode is prepared in the doped region by at least one of the following methods: screen printing, spraying, roller coating, laser transfer, and coating.

[0017] This application embodiment also provides a battery cell, which is processed using any of the above-described battery cell processing methods. The battery cell includes a substrate, a passivation layer, and an electrode. The opposite sides of the substrate are a first surface and a second surface, respectively. The first surface and / or the second surface has a textured surface. The first surface and / or the second surface has a first region and a second region. A second region is disposed between adjacent first regions. The first region has a doped region located within the substrate. The passivation layer is disposed on both the first surface and the second surface. The electrode is disposed in the first region.

[0018] This application also provides a photovoltaic module, which includes a solar cell prepared by any of the above-described processing methods or the solar cell described above.

[0019] This application relates to the photovoltaic field. This application provides a method for processing a solar cell, a solar cell, and a photovoltaic module. The processing method includes texturing a first surface and / or a second surface of a substrate, depositing and curing a doping paste on the surface of a first region to form a doped region in the first region, passivating the substrate, and fabricating electrodes at corresponding positions in the doped region. The beneficial effects of the solution provided by this application are: the processing method for the solar cell involves fewer wet etching steps, resulting in a simpler process and lower cost; simultaneously, the processed solar cell exhibits lower Auger recombination, higher open-circuit voltage, higher conversion efficiency, and better overall performance. Attached Figure Description

[0020] Figure 1 A schematic diagram of the substrate provided in the embodiments of this application; Figure 2 This is a schematic flowchart of the processing method provided in the embodiments of this application; Figure 3 This is a schematic diagram of the substrate after texturing, provided in an embodiment of this application. Figure 4 This is a schematic diagram of the substrate after the doped slurry has been applied to it, as provided in the embodiments of this application. Figure 5 This is a schematic diagram of a doped region formed on a substrate, provided as an embodiment of this application; Figure 6 This is a schematic diagram of the substrate after passivation, provided in an embodiment of this application; Figure 7 This is a schematic diagram of the electrode fabrication process on the substrate, provided in an embodiment of this application. Figure 8 This is a schematic diagram of a battery cell with a stepped structure provided in an embodiment of this application; Figure 9A schematic diagram of a battery cell without a stepped structure provided in an embodiment of this application; Figure 10 This is a schematic diagram of the process for directly doping both the first and second surfaces, provided as an embodiment of this application. Figure 11 This is a schematic diagram showing the application of the present application with a doped slurry on the first surface; Figure 12 This is a schematic diagram of the first surface after a doped region has been formed, provided in an embodiment of this application. Figure 13 This is a schematic diagram showing the application of the present application with a doped slurry on the second surface; Figure 14 This is a schematic diagram of the second surface after a doped region has been formed, provided in an embodiment of this application. Figure 15 This is a schematic diagram of a diffusion region formed on a substrate, provided in an embodiment of this application. Figure 16 This is a schematic diagram of activating the diffusion region to form a doped region, provided in an embodiment of this application. Figure 17 This is a schematic diagram illustrating the process of diffusion and activation of the first and second surfaces, respectively, provided in an embodiment of this application. Figure 18 This is a schematic diagram of the formation of a first diffusion region on the first surface provided in an embodiment of this application; Figure 19 A schematic diagram showing the formation of a first doped region after activation of the first diffusion region, provided in an embodiment of this application. Figure 20 This is a schematic diagram of the formation of a second diffusion region on the second surface provided in an embodiment of this application; Figure 21 A schematic diagram showing the formation of a second doped region after activation of the second diffusion region, as provided in an embodiment of this application. Figure 22 This is a schematic diagram of the battery cell provided in an embodiment of this application.

[0021] 1-Base; 11-First surface; 12-Second surface; 13-First Zone; 14-Second Zone; 2- Doped slurry; 3-Doped region; 31 - First doped region; 32 - Second doped region; 4-Diffusion region; 41 - First diffusion zone; 42 - Second diffusion region; 5-Passivation layer; 6-Electrode. Detailed Implementation

[0022] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0023] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0026] like Figure 1 As shown, this application embodiment provides a method for processing a battery cell. The substrate 1 of the battery cell includes a first surface 11 and a second surface 12. Along the thickness direction of the substrate 1, the first surface 11 and the second surface 12 are located on opposite sides of the substrate 1. The first surface 11 and / or the second surface 12 includes a first region 13 and a second region 14, with the second region 14 disposed between adjacent first regions 13. Figure 2 As shown, the processing method of the solar cell includes: S1. Texturing the first surface 11 having the first region 13 and / or the second surface 12 having the first region 13; S2. A doped paste 2 is applied to the surface of the first region 13 and cured, thereby forming a doped region 3 in the first region 13; S3. Passivate substrate 1; S4. Electrode 6 is prepared at the corresponding position in doped region 3.

[0027] Along the thickness direction of the substrate 1, the two opposite sides of the substrate 1 are a first surface 11 and a second surface 12, respectively. The first surface 11 has a first region 13 and a second region 14, and / or the second surface 12 has a first region 13 and a second region 14. A second region 14 is disposed between adjacent first regions 13. The first region 13 is used for doping and forming a doped region 3, and the second region 14 is used as an isolation region to separate adjacent doped regions 3.

[0028] The first surface 11 and / or the second surface 12 of the substrate 1 are texturized to create a surface-textured light-trapping structure on the substrate 1, including but not limited to forming upright pyramids, inverted pyramids, worm-like structures, etc., on the surface of the substrate 1. After step S1, the structure of the substrate 1 is as follows: Figure 3 As shown. Texturing the surface of substrate 1 can change its reflectivity, increase the number of light reflections, thereby improving the light absorption efficiency of substrate 1 and thus increasing the efficiency of the solar cell. After step S2, the structure of substrate 1 is as follows. Figure 4 As shown. By providing a doped paste 2 in the first region 13, and allowing the doped paste 2 to diffuse into the substrate 1, a doped region 3 can be formed in the first region 13 of the substrate 1, such as... Figure 5 As shown, the doped region 3 is located inside the substrate 1. The doped region 3 is located inside the substrate 1, meaning that the surface of the doped region 3 facing outwards from the substrate 1 is flush with the surface of the substrate 1. Excess doping paste 2 can be removed by cleaning. The second region 14 does not have doping paste 2, therefore, the second region 14 does not form the doped region 3. In the solution provided in this application embodiment, the doped region 3 is formed by the diffusion of doping paste 2 into the substrate 1. The doped region 3 does not protrude relative to the surface of the substrate 1, meaning the doped region 3 is embedded inside the substrate 1. Afterwards, the substrate 1 is passivated, and after passivation, the structure of the substrate 1 is as shown... Figure 6 As shown. Electrode 6 is fabricated at the corresponding position in doped region 3. After fabricating electrode 6, the structure of substrate 1 is as follows. Figure 7 As shown.

[0029] In the battery cell processing method provided in this application embodiment, after texturing the substrate 1, the subsequent steps only involve wet etching of the substrate 1 during cleaning. The main processing steps do not include wet etching; therefore, the final battery cell does not have a stepped surface structure. The surface of the first region 13 with doped regions 3 and the surface of the second region 14 without doped regions 3 are at the same height. This design facilitates carrier separation and transport. When the doped regions 3 protrude relative to the surface of the substrate 1, as... Figure 8 As shown, Figure 8 The dashed lines represent the paths of charge carriers. The transport path of charge carriers to the doped region 3 is singular, and they can only be separated and utilized on the surface of the doped region 3 facing the interior of the substrate 1. The processing method provided in this application yields a solar cell as shown in the embodiment. Figure 9 As shown, Figure 9 The dashed line represents the path of the charge carriers. The doped region 3 is embedded inside the substrate 1. The doped region 3 has a large internal surface of the substrate 1 and has multiple internal surfaces. In addition to the surface of the doped region 3 facing the inside of the substrate 1, the surfaces around the doped region 3 are also located inside the substrate 1. Therefore, the charge carriers can be separated and utilized on multiple surfaces of the doped region 3, and the transmission distance can be shortened.

[0030] When the surface of the substrate 1 has a stepped structure, and there is a height difference between the first region 13 and the second region 14, it will affect the deposition of the passivation layer 5. The crystal orientation at the edge of the stepped structure is disordered, and the coverage and density of the passivation layer 5 are not high, resulting in poor passivation effect. In the solution provided in the embodiments of this application, the first region 13 and the second region 14 are at the same height position, with no step height difference, and the surface of the substrate 1 is relatively flat, which is beneficial to improving the deposition quality of the passivation layer 5.

[0031] In one possible implementation, step S2 includes: Step S21: Apply doping paste 2 to the surface of the first region 13 and cure it to directly dope the first region 13 to form a doped region 3.

[0032] In the solution provided in this application embodiment, the first region 13 can be directly doped. The doping steps typically include diffusion and activation. Diffusion refers to the diffusion of the dopant slurry 2 into the interior of the substrate 1, while activation enhances the electroactivity of the dopant. Direct doping means that diffusion and activation occur simultaneously. This approach integrates diffusion and activation into a single step, reducing the processing steps for solar cells.

[0033] When both the first surface 11 and the second surface 12 of the substrate 1 include the first region 13, i.e., when double-sided doping and activation of the substrate 1 are required, a direct doping method is used, simultaneously diffusing and activating both sides of the substrate 1. This method allows the doped regions 3 of the first surface 11 and the second surface 12 to be processed under the same conditions, thereby improving the consistency of the first surface 11 and the second surface 12, reducing the differences between them, and making the structure of the two sides of the substrate 1 more consistent. This design helps to improve the bifaciality of the solar cell, which is the ratio of the power generation capacity of the back side of the solar cell to the power generation capacity of the front side. A higher bifaciality indicates that the power generation capacity of the back side of the solar cell is closer to that of the front side. The utilization rate of reflected and scattered light by the solar cell is higher. The power generation of the solar cell is increased, thus improving the efficiency of the photovoltaic module.

[0034] like Figure 10 As shown, in one possible implementation, step S2 may include: like Figure 11As shown, in step S22, a doped paste 2 is applied to the surface of the first region 13 of the first surface 11 and cured, as follows: Figure 12 As shown, the first region 13 of the first surface 11 is directly doped to form the first doped region 31.

[0035] Step S23: Clean the substrate 1.

[0036] like Figure 13 As shown, in step S24, a doped paste 2 is applied to the surface of the first region 13 of the second surface 12 and cured, as follows: Figure 14 As shown, the first region 13 of the second surface 12 is directly doped to form the second doped region 32.

[0037] When the solar cell is a bifacial cell, the doping regions 3 of the first surface 11 and the second surface 12 can be processed separately during the processing of the doping region 3. This method reduces the difficulty of doping the substrate 1. Separately doping the first surface 11 and the second surface 12 also allows for adjustment of the doping slurry 2 and changes in the doping type, thereby improving the performance of the solar cell. Processing both sides separately during doping provides a wider process window. Process parameters can be adjusted according to actual conditions during processing, improving the doping effect while reducing the impact on the other side, thus enhancing the overall doping effect of the solar cell and improving its performance. Stepwise doping of the first surface 11 and the second surface 12 of the substrate 1 can improve the efficiency of the solar cell, enhance structural stability, improve production quality, and reduce production costs.

[0038] In one possible implementation, step S2 includes: Step S25: Directly doping the first region 13 by at least one of high-temperature heat treatment, high-energy particle irradiation, and laser annealing activation.

[0039] High-temperature heat treatment offers high activation efficiency and ensures uniform temperature across the entire surface of substrate 1. High-energy particle irradiation operates at lower temperatures during processing, reducing the impact of temperature on substrate 1 and minimizing heat diffusion. Laser annealing activation has minimal thermal impact on substrate 1, offering high activation efficiency and processing precision. Different processing techniques can be selected based on specific requirements during actual processing to improve the quality of the solar cells.

[0040] In one possible implementation, the high-temperature heat treatment conditions are as follows: a treatment temperature of 750°C to 1100°C, an inert gas atmosphere (nitrogen atmosphere may be used), a treatment pressure of 10 mbar to atmospheric pressure, and a treatment time of 5 to 60 minutes; followed by a treatment temperature of 750°C to 1100°C, an oxygen atmosphere, a treatment pressure of 10 mbar to atmospheric pressure, and a treatment time of 10 to 180 minutes.

[0041] The conditions for high-energy particle irradiation are as follows: ionization of inert gas is used to accelerate the particles to bombard the material for high-energy particle irradiation; particle energy is 10 keV to 1 MeV; incident angle is 90 degrees; and vacuum level is 10. -4 Pa to 10 -7 Pa.

[0042] The conditions for laser annealing activation are as follows: using an infrared laser with a wavelength of 1024 nm, a laser power of 100 W to 2000 W, a spot size of 30 μm to 900 μm, and stacked spot scanning at a scanning speed of 0.2 m / s to 8 m / s. The infrared laser can be a nano-infrared laser, and the spot can be square or circular.

[0043] In actual processing, different processing techniques and corresponding process conditions can be selected according to requirements. Simultaneous diffusion and activation of substrate 1 during processing can reduce the number of process steps and improve processing efficiency. Performing diffusion and activation simultaneously can reduce the number of high-temperature processes, thereby reducing thermal damage and improving the quality of the solar cells.

[0044] In one possible implementation, step S2 includes: like Figure 15 As shown, in step S26, a doped paste 2 is applied to the surface of the first region 13, allowing the doped paste 2 to diffuse into the first region 13 to form a diffusion region 4. Figure 16 As shown, diffusion region 4 is activated to form doped region 3.

[0045] When doping substrate 1, diffusion and activation are performed stepwise, with diffusion occurring first, followed by activation. Both diffusion and activation are independent and controllable steps, allowing for more targeted processing. Treating diffusion and activation as relatively independent steps allows for better control over the doping depth and concentration distribution. Different processes can be selected for doping and activation, which helps to improve both doping quality and activation efficiency, thereby improving the overall quality of the solar cell.

[0046] like Figure 17 As shown, in one possible implementation, the method for processing the solar cell includes: Step S261: Apply the doped paste 2 to the surface of the first region 13 of the first surface 11 and cure it, such as... Figure 18 As shown, the doped slurry 2 is diffused to the first region 13 of the first surface 11 to form a first diffusion region 41. The first diffusion region 41 is activated, as shown in the figure. Figure 19 As shown, the first doped region 31 is formed.

[0047] Step S262, Clean the substrate 1.

[0048] Step S263: Apply the doped paste 2 to the surface of the first region 13 of the second surface 12 and cure it, such as... Figure 20 As shown, the doped slurry 2 diffuses to the first region 13 of the second surface 12 to form a second diffusion region 42. Figure 21 As shown, the second diffusion region 42 is activated to form the second doped region 32.

[0049] When the solar cell is a bifacial cell, the first surface 11 and the second surface 12 can be processed in steps. First, the first surface 11 is processed to form a doped region 3, and then the second surface 12 is processed to form the doped region 3. Furthermore, the doped regions 3 on both the first and second surfaces 11 undergo diffusion followed by activation during processing. By doping different surfaces of the substrate 1 separately, targeted treatment can be performed according to the actual conditions of each surface, thereby improving the doping effect and the performance of the solar cell. During the doping of each surface, diffusion and activation are also performed step-by-step. That is, the doping of different surfaces, as well as the diffusion and activation during doping, are all independent and controllable steps. This allows for more flexible process selection during processing, enabling the selection of different doping, diffusion, and activation processes based on the actual conditions of each surface, thus improving the doping quality of the substrate 1 and consequently enhancing the performance of the solar cell.

[0050] In one possible implementation, step S26 may include: Step S264: The doped slurry 2 is diffused into the first region 13 to form a diffusion region 4 by at least one of the following methods: high temperature heat treatment, high energy particle irradiation, and laser annealing activation.

[0051] In actual processing, different diffusion processes can be selected according to requirements.

[0052] In one possible implementation, when diffusion is carried out using high-temperature heat treatment, the conditions for high-temperature heat treatment are: treatment temperature of 750°C to 1100°C, treatment time of 5 minutes to 30 minutes, inert gas atmosphere, and treatment pressure of 10 mbar to atmospheric pressure.

[0053] When diffusion is performed using high-energy particle irradiation, the conditions for high-energy particle irradiation are as follows: ionization of inert gas is used to accelerate the particles to bombard the material for high-energy particle irradiation; particle energy ranges from 10 keV to 700 keV; incident angle is 90 degrees; and vacuum level is 10. - 4 Pa to 10 -7 Pa.

[0054] When using laser annealing activation for diffusion, the conditions for laser annealing activation are as follows: infrared laser with a wavelength of 1024nm, laser power of 100W to 1000W, spot size of 30um to 900um, spot stacking scanning, and scanning speed of 0.2m / s to 8m / s.

[0055] By separating diffusion and activation into relatively independent steps, and with the doping processes of the first surface 11 and the second surface 12 also being relatively independent, different diffusion processes can be selected based on the different conditions of the first surface 11 and the second surface 12 during diffusion. This allows for more targeted adjustments to the process parameters, thereby improving the doping quality of the first surface 11 and the second surface 12, increasing the bifaciality of the solar cell, and ultimately improving the cell's efficiency.

[0056] In one possible implementation, step S26 further includes: Step S265: Activate diffusion zone 4 by high-temperature heat treatment. The high-temperature heat treatment conditions are: treatment temperature 750℃ to 1100℃, treatment time 10 minutes to 180 minutes, oxygen atmosphere, and treatment pressure 10 mbar to atmospheric pressure.

[0057] High-temperature heat treatment results in higher uniformity and activation rate during activation, which helps improve the quality of the solar cells.

[0058] In one possible implementation, step S2 further includes: Step S27: The doping type of the first region 13 of the first surface 11 is different from the doping type of the second region 14 of the second surface 12.

[0059] By using different types of doping pastes 2 on the first surface 11 and the second surface 12, it is beneficial to improve the efficiency of the solar cell and optimize the performance of the two sides of the solar cell respectively, which is beneficial to improve the open circuit voltage and fill factor of the solar cell.

[0060] In one possible implementation, step S3 includes: Step S31: Clean substrate 1 to remove slurry residue and oxide layer from the surface of substrate 1.

[0061] Step S32: Form a passivation layer 5 on the surface of substrate 1.

[0062] Cleaning the substrate 1 can reduce the impact of residual slurry and oxide layer on the passivation layer 5, thereby improving the performance of the solar cell.

[0063] In one possible implementation, step S4 includes: Step S41: Prepare electrode 6 in doped region 3 by at least one of screen printing, spraying, roller coating, laser transfer, or coating.

[0064] The battery cell processing method provided in this application embodiment can simultaneously dope the first surface 11 and the second surface 12 of the substrate 1, or it can dope the first surface 11 first and then the second surface 12. When the first surface 11 and the second surface 12 of the substrate 1 are doped simultaneously, diffusion and activation can be performed simultaneously through a single process step, or diffusion can be performed first and then activation can be performed as two relatively independent process steps. When the first surface 11 and the second surface 12 are doped separately, both the first surface 11 and the second surface 12 can be directly doped, i.e., diffusion and activation can be performed simultaneously. Alternatively, diffusion and activation can be separated into relatively independent process steps.

[0065] The battery cell processing method provided in this application embodiment is simple, has a short process flow, and low cost. Furthermore, it involves fewer wet processing steps, resulting in less etching consumption of the substrate 1 and further lower production costs. Both the front and back sides of the battery employ excited carrier directional transport-assisted reduction of metal ions to form ohmic contacts, resulting in extremely low recombination at the electrode 6, typically not exceeding 100 fA / cm. 2 Metal-formed alloys exhibit minimal corrosion of silicon and high battery efficiency.

[0066] This application also provides a battery cell, which can be processed using the battery cell processing methods described in any of the above embodiments.

[0067] like Figure 22 As shown, the battery cell includes a substrate 1, a passivation layer 5, and an electrode 6. The substrate 1 has a first surface 11 and a second surface 12 on opposite sides, and both the first surface 11 and / or the second surface 12 have a textured surface. The first surface 11 and / or the second surface 12 have a first region 13 and a second region 14. A second region 14 is disposed between adjacent first regions 13. A doped region 3 is located within the substrate 1. Both the first surface 11 and the second surface 12 are provided with the passivation layer 5. The electrode 6 is disposed in the first region 13.

[0068] The doped layer of the solar cell provided in this embodiment is located within the substrate 1, and the surface of the doped layer is not higher than the surface of the substrate 1. There is no height difference between the doped region 3 and the undoped region 3 of the solar cell (the height difference of the substrate 1 surface due to texturing is negligible), i.e., there is no step structure. Therefore, it is beneficial to improve the deposition quality of the passivation layer 5 and has a better passivation effect. The Auger recombination of the solar cell is low, the on-time voltage is high, the conversion efficiency is high, and the overall performance of the solar cell is improved. At the same time, the doping of the first surface 11 and the second surface 12 of the solar cell can be carried out simultaneously. Therefore, the consistency of doping concentration, resistivity, and reflectivity of the two sides of the solar cell is better, and the bifaciality of the solar cell can be increased to 98% to 100%.

[0069] This application also provides a photovoltaic module, which may include the solar cells involved in any of the above embodiments. Since the solar cells have the above technical effects, the photovoltaic module including the solar cells also has the corresponding technical effects, which will not be elaborated here.

[0070] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for processing battery cells, characterized in that, The first surface (11) and / or the second surface (12) of the substrate (1) of the solar cell include a first region (13) and a second region (14), with the second region (14) disposed between adjacent first regions (13), and the processing method of the solar cell includes: Texturing the first surface (11) having the first region (13) and / or the second surface (12) having the first region (13); Doping paste (2) is applied to the surface of the first region (13) and cured, and a doped region (3) is formed in the first region (13). The surface of the first region (13) with the doped region (3) and the surface of the second region (14) without the doped region (3) are at the same height. The substrate (1) is passivated; An electrode (6) is prepared at the corresponding position of the doped region (3).

2. The method for processing battery cells according to claim 1, characterized in that, The steps of setting and curing the doped paste (2) in the first region (13) and forming the doped region (3) in the first region (13) include: The doping paste (2) is applied to the surface of the first region (13) and cured, and the first region (13) is directly doped to form the doped region (3).

3. The method for processing battery cells according to claim 2, characterized in that, The steps of applying the doping paste (2) to the surface of the first region (13) and curing it, and directly doping the first region (13) to form the doped region (3) include: The doping paste (2) is applied to the surface of the first region (13) of the first surface (11) and cured, and the first region (13) of the first surface (11) is directly doped to form a first doped region (31). Clean the substrate (1); The doping paste (2) is applied to the surface of the first region (13) of the second surface (12) and cured, and the first region (13) of the second surface (12) is directly doped to form a second doped region (32).

4. The method for processing battery cells according to claim 2, characterized in that, The steps of applying the doping paste (2) to the surface of the first region (13) and curing it, and directly doping the first region (13) to form the doped region (3) include: The first region (13) is directly doped by at least one of the following methods: high-temperature heat treatment, high-energy particle irradiation, and laser annealing activation.

5. The method for processing battery cells according to claim 4, characterized in that, The conditions for high-temperature heat treatment are as follows: treatment temperature of 750℃ to 1100℃, inert gas atmosphere, treatment pressure of 10mbar to atmospheric pressure, treatment time of 5 to 60 minutes, followed by treatment temperature of 750℃ to 1100℃, oxygen atmosphere, treatment pressure of 10mbar to atmospheric pressure, treatment time of 10 to 180 minutes. The conditions for high-energy particle irradiation are as follows: ionization of inert gas is used to accelerate the particles to bombard the material for high-energy particle irradiation; particle energy is 10 keV to 1 MeV; incident angle is 90 degrees; and vacuum level is 10. -4 Pa to 10 -7 Pa; The conditions for laser annealing activation are as follows: infrared laser is used, with a laser wavelength of 1024nm, laser power of 100W to 2000W, spot size of 30um to 900um, spot stacking scanning, and scanning speed of 0.2m / s to 8m / s.

6. The method for processing battery cells according to claim 1, characterized in that, The steps of applying and curing a doped paste (2) on the surface of the first region (13) and forming a doped region (3) in the first region (13) include: The doping paste (2) is disposed on the surface of the first region (13) and the doping paste (2) is diffused into the first region (13) to form a diffusion region (4); the diffusion region (4) is activated to form the doping region (3).

7. The method for processing battery cells according to claim 6, characterized in that, The steps of depositing the doped paste (2) on the surface of the first region (13), allowing the doped paste (2) to diffuse into the first region (13) to form a diffusion region (4), and activating the diffusion region (4) to form the doped region (3) include: The doping paste (2) is applied to the surface of the first region (13) of the first surface (11) and cured, so that the doping paste (2) diffuses to the first region (13) of the first surface (11) to form a first diffusion region (41), and the first diffusion region (41) is activated to form a first doping region (31). Clean the substrate (1); The doping paste (2) is applied to the surface of the first region (13) of the second surface (12) and cured, so that the doping paste (2) diffuses to the first region (13) of the second surface (12) to form a second diffusion region (42), and the second diffusion region (42) is activated to form a second doping region (32).

8. The method for processing battery cells according to claim 6, characterized in that, The doped paste (2) is disposed on the surface of the first region (13), and the doped paste (2) diffuses into the first region (13) to form a diffusion region (4). The step of activating the diffusion region (4) includes: The doped slurry (2) is diffused into the first region (13) to form the diffusion region (4) by at least one of the following methods: high-temperature heat treatment, high-energy particle irradiation, and laser annealing activation.

9. The method for processing a battery cell according to claim 8, characterized in that, The conditions for high-temperature heat treatment are: treatment temperature 750℃ to 1100℃, treatment time 5 minutes to 30 minutes, inert gas atmosphere, and treatment pressure 10 mbar to atmospheric pressure. The conditions for high-energy particle irradiation are as follows: ionization of inert gas is used to accelerate the particles to bombard the material for high-energy particle irradiation; particle energy ranges from 10 keV to 700 keV; incident angle is 90 degrees; and vacuum level is 10. -4 Pa to 10 -7 Pa; The conditions for laser annealing activation are as follows: infrared laser with a wavelength of 1024nm, laser power of 100W to 1000W, spot size of 30um to 900um, spot stacking scanning, and scanning speed of 0.2m / s to 8m / s.

10. The method for processing a battery cell according to claim 6, characterized in that, The doped paste (2) is disposed on the surface of the first region (13), and the doped paste (2) diffuses into the first region (13) to form a diffusion region (4). The step of activating the diffusion region (4) includes: The diffusion region (4) is activated by high-temperature heat treatment; The conditions for high-temperature heat treatment are: treatment temperature 750℃ to 1100℃, treatment time 10 minutes to 180 minutes, oxygen atmosphere, and treatment pressure 10 mbar to atmospheric pressure.

11. A method for processing a battery cell according to any one of claims 1 to 10, characterized in that, The steps of applying and curing a doped paste (2) on the surface of the first region (13) and forming a doped region (3) in the first region (13) include: The doping type of the first region (13) of the first surface (11) is different from the doping type of the first region (13) of the second surface (12).

12. A method for processing a battery cell according to any one of claims 1 to 10, characterized in that, The passivation step of the substrate (1) includes: Clean the substrate (1) to remove slurry residue and oxide layer from the surface of the substrate (1); A passivation layer (5) is formed on the surface of the substrate (1).

13. A method for processing a battery cell according to any one of claims 1 to 10, characterized in that, The step of fabricating the electrode (6) at the corresponding position in the doped region (3) includes: The electrode (6) is prepared in the doped region (3) by at least one of the following methods: screen printing, spraying, roller coating, laser transfer, and coating.

14. A battery cell, wherein the battery cell is processed using the processing method of any one of claims 1 to 13, characterized in that, The battery cell includes a substrate (1), a passivation layer (5), and an electrode (6). The substrate (1) has a first surface (11) and a second surface (12) on opposite sides. The first surface (11) and / or the second surface (12) have a textured surface. The first surface (11) and / or the second surface (12) have a first region (13) and a second region (14). The second region (14) is disposed between adjacent first regions (13). The first region (13) has a doped region (3). The doped region (3) is located within the substrate (1). The passivation layer (5) is disposed on both the first surface (11) and the second surface (12). The electrode (6) is disposed in the first region (13). The surface of the first region (13) having the doped region (3) and the surface of the second region (14) not having the doped region (3) are at the same height.

15. A photovoltaic module, characterized in that, The photovoltaic module includes a cell prepared by the processing method of any one of claims 1 to 13 or the cell as described in claim 14.

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