Silicon heterojunction solar cell electric injection method and system

Abstract

The invention relates to the technical field of silicon heterojunction solar cells, in particular to a silicon heterojunction solar cell electric injection method and system. Comprising the following steps: placing a mask plate printed with a grid line pattern on two sides of a solar heterojunction battery piece, performing exposure patterning treatment to prepare a grid line groove, performing pretreatment on the solar heterojunction battery piece subjected to patterning treatment, placing the pretreated solar heterojunction battery piece into an electroplating device for electroplating, and plating a copper grid line on a copper seed layer in the grid line groove; replacing a current source on any side of the clamp in the electroplating device after electroplating is finished, so that the clamps on the two sides form a positive electrode and a negative electrode; continuously introducing current for electric injection to obtain a battery semi-finished product; and removing the mask layer and the seed layer on the front surface and the back surface of the cell semi-finished product to obtain a silicon heterojunction solar cell finished product. Different electroplating and electric injection processes are realized by adopting the same set of electroplating equipment, so that the equipment cost can be reduced, and meanwhile, the high conversion efficiency of the heterojunction battery can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of silicon heterojunction solar cells, and in particular to an electric injection method and system for silicon heterojunction solar cells. Background Art

[0002] With the rapid development of the photovoltaic industry, the industrialization preparation technology of solar cells is becoming more and more diversified, and the preparation cost is becoming lower and lower. Heterojunction cells are currently the solar cells with the highest market share due to their high photoelectric conversion efficiency. The electroplating process is an important step in the preparation of heterojunction cells. Metal electrodes can be formed on the surface of the cell through electroplating. Due to the high electrical conductivity of copper itself and the low-temperature process adapted to heterojunction cells, plus electroplating can achieve narrower grid lines and improve light management. Copper-grid heterojunctions can achieve higher photoelectric conversion efficiency.

[0003] Some studies on multicrystalline photovoltaic cells believe that during the current injection process, hydrogen in the SiNx (silicon nitride film):H layer will passivate defects with carrier recombination activity. Carrier injection of crystalline silicon cells is believed to remove defects at the interface and achieve better passivation effects. During the electrical injection process, by applying positive bias and annealing at a specific temperature, a significant increase in cell efficiency can be obtained. The essence of electrical injection is to inject carriers, which is the same as light injection. Therefore, electrical injection is also a very important alternative processing method in the photovoltaic industry.

[0004] In the prior art, in the preparation process of copper-grid-silicon heterojunction solar cells, after the copper grid metallization process is completed, a light injection process will be performed, the purpose of which is to achieve a better passivation effect and a higher cell conversion efficiency. However, the main structure of the light injection device is generally composed of LED infrared lamps with high luminous efficiency, so the cost is very expensive, and the cavity temperature is high during the light injection process, which brings a greater oxidation risk to the copper-grid-silicon heterojunction cell, thereby affecting the reliability and weldability of the cell, and is not conducive to the sustainability of future products. Therefore, there is currently no relevant electric injection technology applied to n-type heterojunction cells, and there is no research involving the use of electroplating equipment to achieve the electric injection process of heterojunction cells. Summary of the invention

[0005] The present invention aims to at least improve one of the technical problems existing in the prior art. To this end, the present invention provides a method and system for electrical injection into a silicon heterojunction solar cell.

[0006] A method for injecting electricity into a silicon heterojunction solar cell according to an embodiment of the first aspect of the present invention comprises: Providing a silicon heterojunction cell with seed layers deposited on the front and back sides; A gate line pattern mask layer is formed on the front and back sides of the silicon heterojunction cell, and an intermediate silicon wafer containing gate line grooves is obtained through exposure and development treatment; Placing the intermediate silicon wafer into an electroplating device for electroplating to obtain copper grid lines; Replace the current source on either side of the fixture in the electroplating device so that the fixtures on both sides form positive and negative electrodes; Continuously supplying current for electrical injection to obtain a semi-finished battery; The mask layer and the seed layer on the front and back sides of the semi-finished cell are removed to obtain a finished silicon heterojunction solar cell.

[0007] According to the electric injection method for silicon heterojunction solar cells of the embodiment of the present invention, by replacing the current source on either side of the fixture in the electroplating device, the fixtures on both sides form positive and negative electrodes, and the same set of electroplating equipment is used to achieve different electroplating and electric injection processes, which can not only reduce the equipment cost but also achieve high conversion efficiency of heterojunction batteries. In addition, the electric injection method of the embodiment of the present invention can also avoid the risk of copper grid-heterojunction batteries being more easily oxidized and affecting the reliability and weldability of the battery due to the high cavity temperature during the light injection process. The process temperature of the electric injection of the present invention is lower, which is more suitable for heterojunction batteries prepared at low temperatures, and more suitable for the preparation of silicon heterojunction solar cells.

[0008] In a possible implementation of the first aspect, the electroplating device includes any one of a flying target hanging electroplating fixture, a basket-type electroplating fixture, and a flexible electrode fixture for horizontal electroplating.

[0009] In a possible implementation of the first aspect, the electroplating device includes: A first alloy fixture connected to the positive or negative pole of a power source; A second alloy fixture is spaced apart from the first alloy fixture and connected to the negative electrode of the power supply; A front clamping plate connected to the first alloy clamp and having a front clamping point at the end; A back clamp is connected to the second alloy clamp, and a back clamp point is provided at the end thereof. The front clamp point and the back clamp point are respectively used to clamp the cell to be plated. The electroplating and electric injection process of the cell to be plated (150) is achieved by adjusting the polarity of the power supply connected to the first alloy clamp, thereby saving a large amount of equipment cost for light injection while maintaining a high efficiency level.

[0010] In a possible implementation of the first aspect, the silicon heterojunction cell has a symmetrical double-sided cell structure, including: The middle is N-type crystalline silicon; The intrinsic amorphous silicon film and the P-type amorphous silicon film are sequentially deposited on the front side to form a PN junction; On the back side, an intrinsic amorphous silicon film and an N-type amorphous silicon film are sequentially deposited to form a back surface field, thereby obtaining a double-sided deposited silicon wafer. Depositing a transparent conductive film on both sides of the silicon wafer after double-sided deposition; Copper electrodes were prepared on TCO thin films.

[0011] In a possible implementation manner of the first aspect, the electric injection current range is between 1A and 50A, the power supply is a direct current power supply, and the electric injection time is between 5min and 30min.

[0012] In a possible implementation manner of the first aspect, after the copper grid lines are obtained, a washing and drying process is further included, wherein the drying temperature ranges from 80° C. to 100° C.

[0013] In a possible implementation manner of the first aspect, after the seed layer is obtained, a secondary washing and secondary drying process is further included, wherein the drying temperature ranges from 100° C. to 150° C.

[0014] In a possible implementation of the first aspect, the seed layer includes pure copper and a copper alloy seed layer doped with different metals, wherein the alloy element is selected from at least one of Cu, Ni, Ta, Mo, W, Ti, Cr, Al, Mg, Sn, Zn, and Ag.

[0015] In a possible implementation of the first aspect, the copper grid line has a front main grid width of 50um to 80um, a front secondary grid width of 10um to 40um, and a height of 5um to 20um; The width of the back main grid is 50um~250um, the width of the back sub grid is 20um~80um; the height is 5um~20um.

[0016] In a possible implementation manner of the first aspect, an intrinsic amorphous silicon film and a P-type amorphous silicon film are sequentially deposited on the front surface with a thickness of 5 nm to 40 nm to form a nn+ high-low heterostructure with the crystalline silicon.

[0017] According to a second aspect of an embodiment of the present invention, a silicon heterojunction solar cell electricity injection system comprises using the above-mentioned method to inject electricity into the silicon heterojunction solar cell.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a flow chart of a method for electrical injection into a silicon heterojunction solar cell according to an embodiment of the present invention; Figure 2 It is a main structural diagram of the electroplating device in the electrical injection method for silicon heterojunction solar cells according to an embodiment of the present invention.

[0021] Reference numerals: Front clamping plate 110, back clamping plate 120, front clamping point 130, back clamping point 140, and battery cell to be plated 150; A first alloy fixture 210 and a second alloy fixture 220 . DETAILED DESCRIPTION

[0022] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] The terms "first", "second", "third", etc. in the specification and claims of the present application and the drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a series of steps or units are included, or optionally, steps or units not listed are included, or optionally, other steps or units inherent to these processes, methods, products or devices are included.

[0026] Only the part relevant to the present application is shown in the accompanying drawings, but not all of the content. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processing or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of each operation can be rearranged. When its operation is completed, the process can be terminated, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0027] The terms "component", "module", "system", "unit", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a unit can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or distributed between two or more computers. In addition, these units can be executed from various computer-readable media having various data structures stored thereon. Units can communicate through local and / or remote processes, for example, based on signals having one or more data packets (e.g., data from a second unit interacting with another unit in a local system, a distributed system, and / or a network. For example, the Internet interacts with other systems via signals).

[0028] Example 1 A method for injecting electricity into a silicon heterojunction solar cell according to an embodiment of the first aspect of the present invention comprises: Providing a silicon heterojunction cell with seed layers deposited on the front and back sides; A gate line pattern mask layer is formed on the front and back sides of the silicon heterojunction cell, and an intermediate silicon wafer containing gate line grooves is obtained through exposure and development treatment; Placing the intermediate silicon wafer into an electroplating device for electroplating to obtain copper grid lines; Replace the current source on either side of the fixture in the electroplating device so that the fixtures on both sides form positive and negative electrodes; Continuously supplying current for electrical injection to obtain a semi-finished battery; The mask layer and the seed layer on the front and back sides of the semi-finished cell are removed to obtain a finished silicon heterojunction solar cell.

[0029] In this embodiment, a method for realizing electric injection of a heterojunction battery using an electroplating device is disclosed, and the method comprises the following steps: Step S1, texturing, placing the silicon wafer in an alkaline mixed solution for reaction, forming a pyramid structure on the front and back surfaces of the silicon wafer, specifically placing the silicon wafer in a mixed solution of KOH or NaOH, a special additive for small velvet and ultrapure water, reacting for 200s to 1800s, forming a pyramid structure on the front and back surfaces of the silicon wafer, and the size of the pyramid is 0.5um to 4um; Step S2, preparing a passivation layer, depositing an intrinsic amorphous silicon layer on the front and back of the silicon wafer containing the pyramid structure, passivating the crystalline silicon interface of the intrinsic amorphous silicon layer, and obtaining a first silicon wafer, wherein the thickness of the crystalline silicon interface is 4nm to 10nm; Step S3, emitter preparation, depositing doped amorphous silicon and nanocrystalline silicon layers on the front and back of the first silicon wafer, respectively, to obtain a first silicon wafer containing an emitter, specifically: using PECVD to deposit phosphorus-doped amorphous silicon and nanocrystalline silicon on the front of the first silicon wafer, respectively, to obtain an nn+ high-low heterostructure formed at the interface with the crystalline silicon, with a thickness of 5nm to 40nm, and depositing boron-doped amorphous silicon and nanocrystalline silicon on the back of the first silicon wafer, respectively, to obtain a back emitter with an np heterostructure formed at the interface with the crystalline silicon, with a thickness of 5nm to 60nm; Step S4, TCO layer preparation, using physical vapor deposition (PVD) or reactive plasma deposition (RPD) to sputter a layer of TCO conductive film on the front and back sides of the first silicon wafer containing the emitter, respectively, to obtain a first silicon wafer containing a TCO layer for collecting carriers; Step S5, electroplating seed layer preparation, depositing seed layers on the front and back of the first silicon wafer containing the TCO layer to obtain the first silicon wafer containing the seed layer, specifically, using PVD to deposit a 10nm to 150nm seed layer on the front and back of the first silicon wafer containing the TCO layer; the seed layer can be roughly divided into three types: copper, nickel, and copper-nickel alloy by using different target materials in the PVD sputtering process; the main function of the seed layer is to enhance the bonding force between the copper grid line and the TCO, which helps the heterojunction battery to achieve double-sided electroplating. If the copper grid line is directly grown on the silicon surface, the sintering link is reduced, which is easy to cause the grid detachment problem; Step S6, preparing an electroplating mask layer, printing a layer of organic photosensitive ink mask layer on the front and back of the first silicon wafer on the electroplating seed layer, respectively, to obtain a first silicon wafer containing a mask layer; Step S7, forming a gate line groove by electroplating, exposing the front and back sides of the first silicon wafer on the electroplating mask layer by a photolithography machine, and then cleaning the exposed first silicon wafer by a developing method, leaving the ink in the mask area, thereby obtaining a second silicon wafer with a gate line groove; Step S8, forming electroplated gate lines, using a vertical continuous electroplating method to electroplate copper gate lines at the gate line grooves, the front main gate width is 50um-80um, the front sub-gate width is 10um-40um, and the height is 5um-20um; the back main gate width is 50um-250um, the back sub-gate width is 20um-80um, and the height is 5um-20um, and copper gate lines are electroplated in the gate line grooves of the second silicon wafer in sequence as positive and negative electrodes to obtain a semi-finished silicon-based heterojunction solar cell; Step S9, electrical injection treatment, performing electrical injection treatment on the semi-finished silicon-based heterojunction solar cell to obtain a semi-finished silicon-based heterojunction solar cell; Step S10, removing the mask layer, immersing the semi-finished silicon-based heterojunction solar cell in an alkaline solution to obtain a semi-finished silicon-based heterojunction solar cell after removing the ink mask layer, specifically immersing the electroplated cell in a mixed solution containing KOH or NaOH for 30s to 200s to remove the ink mask layer; Step S11, removing the seed layer, immersing the semi-finished silicon-based heterojunction solar cell after removing the ink mask layer in an acid solution for pickling to remove the seed layer and obtain a finished silicon-based heterojunction solar cell. Specifically, the cell is immersed in a dilute sulfuric acid or dilute nitric acid solution for 30s to 100s to remove the seed layer except the copper grid line, and then cleaned with ultrapure water and dried to obtain a finished silicon-based heterojunction solar cell.

[0030] According to the electric injection method for silicon heterojunction solar cells of the embodiment of the present invention, by replacing the current source on either side of the fixture in the electroplating device, the fixtures on both sides form positive and negative electrodes, and the same set of electroplating equipment is used to achieve different electroplating and electric injection processes, which can not only reduce the equipment cost but also achieve high conversion efficiency of heterojunction batteries. In addition, the electric injection method of the embodiment of the present invention can also avoid the risk of copper grid-heterojunction batteries being more easily oxidized and affecting the reliability and weldability of the battery due to the high cavity temperature during the light injection process. The process temperature of the electric injection of the present invention is lower, which is more suitable for heterojunction batteries prepared at low temperatures, and more suitable for the preparation of silicon heterojunction solar cells.

[0031] In this embodiment, a plating device is specifically disclosed, including: A first alloy fixture 210 connected to the positive or negative pole of a power source; A second alloy fixture 220 is spaced apart from the first alloy fixture 210 and connected to the negative electrode of the power supply; A front clamping plate 110, connected to the first alloy clamp 210, with a front clamping point 130 at the end thereof; The back clamp 120 is connected to the second alloy clamp 220, and a back clamp point 140 is provided at the end. The front clamp point 130 and the back clamp point 140 are respectively used to clamp the battery cell 150 to be plated. The electroplating and electric injection process of the battery cell 150 to be plated is realized by adjusting the polarity of the power supply connected to the first alloy clamp 210, which can save a lot of equipment cost for light injection while maintaining a high efficiency level.

[0032] Furthermore, the chemical principle of using the present electroplating device to achieve electroplating of copper grid lines is as follows: at the beginning of electroplating, the clamping point on one side of the cell 150 to be plated, i.e., the point where the electroplating seed layer is exposed, needs to be in contact with the front clamping point 130 and the back clamping point 140 of the clamp, so that the current can be conducted and the grid lines can grow. At the same time, the first alloy clamp 210 and the second alloy clamp 220 need to be connected to an external DC power supply to also introduce external current. At this time, the power supplies of the first alloy clamp 210 and the second alloy clamp 220 are both negative electrodes, and the electroplating solution is the positive electrode. Due to the principle of the electrolytic cell, the copper ions in the electroplating solution are gradually reduced to single copper on the conductive electroplating seed layer due to the acquisition of electrons. This is the electrical principle of electroplating copper grid lines.

[0033] The specific steps include: (1) The cell 150 to be plated with the gate line grooves is first cleaned in a pre-preg tank to remove the residual ink and oxide layer in the grooves; (2) After passing through the pre-preg tank, the next step is to enter the electroplating device, and the battery cell 150 to be plated grows a grid line in the groove, with a height of 15um and a width of 20um.

[0034] (3) After passing through the electroplating device, the next step is to enter the cleaning tank to clean the residual liquid and dirt on the surface of the electroplated battery cell.

[0035] Further, the physicochemical principle of the electroplating device to realize the electric injection process is as follows: from the perspective of defect change, the boron ion doping effect will be better after current injection, which will cause weak bonds to break and form stronger covalent bonds, thereby increasing the PL count after current injection, and some small dark areas disappear, indicating that the internal defects of the HJT cell are passivated after treatment. The reason for the enhancement can also be inferred that the current injection promotes the non-equilibrium carriers generated during the H diffusion process, resulting in enhanced passivation of the composite center at the ia-Si:H / c-Si interface, thereby improving Voc. In addition, the current intensity also has a significant effect on the reaction rate, and the two are in a linear relationship. Therefore, reasonable control of temperature and current intensity during the treatment process will reduce costs while obtaining better performance improvements. When performing electrical injection, the connection power supply of the first alloy fixture 210 is switched to the positive pole, and the second alloy fixture 220 is still connected to the negative pole, so as to perform the electrical injection process.

[0036] The specific steps include: (1) After the battery passes through the cleaning tank, the first alloy fixture 210 and the second alloy fixture 220 are both in a power-off state, and the battery is placed in a 120° C. oven for a drying process of 1 to 2 minutes.

[0037] (2) After the battery is dried, direct current is passed through the first alloy fixture 210 and the second alloy fixture 220. The first alloy fixture 210 is connected to the positive pole of the power supply, and the second alloy fixture 220 is connected to the negative pole of the power supply. The current density during the electric injection process is adjusted to 100 mA / cm2, and the electric injection time is 1 min to 2 min.

[0038] (3) After the electrical injection process is completed, the battery is unloaded and the subsequent process is carried out, thus completing the entire electrical injection process.

[0039] It should be noted that the current range of the electrical injection is between 1A and 50A, the power supply is a DC power supply, and the electrical injection time includes but is not limited to 5 minutes to 30 minutes.

[0040] It should be noted that after the copper grid lines are obtained, a washing and drying process is also included, wherein the drying temperature ranges from 80°C to 100°C.

[0041] It should be noted that after obtaining the seed layer, a secondary washing and secondary drying process is also included, wherein the drying temperature ranges from 100°C to 150°C.

[0042] It should be noted that the seed layer includes pure copper and a copper alloy seed layer doped with different metals, wherein the alloy element is selected from at least one of Cu, Ni, Ta, Mo, W, Ti, Cr, Al, Mg, Sn, Zn, and Ag.

[0043] Under standard test conditions, the silicon-based heterojunction solar cells prepared in Example 1 and Comparative Example 1 (existing light injection) were tested for cell performance, and the results are shown in Table 1 below: Conclusion: From the experimental data in the above table, it can be seen that the efficiency of the cell after electrical injection has increased by 0.63%, which is more obvious than that of light injection. The main reason is that the current carrier injection leads to a better boron ion doping effect, which will cause weak bonds to break and form stronger covalent bonds, thereby increasing the PL count after current injection and disappearing some small dark areas, indicating that the internal defects of the SHJ cell are passivated after treatment. The reason for the enhancement can also be inferred that the current injection promotes the non-equilibrium carriers generated during the H diffusion process, resulting in enhanced passivation of the recombination center at the ia-Si:H / c-Si interface, thereby significantly improving Voc and FF. At the same time, the market price of a 300MW light injection device may be around 500W. Electroplating and electrical injection are achieved using electroplating equipment. The increased cost is mainly due to the modification of the fixture of the equipment, which may cost around 50W, so it is equivalent to reducing the cost of 450W without reducing the efficiency.

[0044] Example 2 This embodiment provides a method for injecting electricity into a silicon heterojunction solar cell, which is a variation of the scheme in Embodiment 1, wherein the vertical continuous electroplating method in step S8 is changed to a basket clamping electroplating method, which is the same as Embodiment 1. The battery obtained under the scheme of this embodiment can still achieve the effect of Embodiment 1 after actual measurement.

[0045] Example 3 This embodiment provides a method for injecting electricity into a silicon heterojunction solar cell, which is a variation of the scheme in Embodiment 1, wherein the vertical continuous electroplating method in step S8 is changed to a horizontal electroplating method, which is the same as Embodiment 1. The battery obtained under the scheme of this embodiment can still achieve the effect of Embodiment 1 after actual measurement.

[0046] Example 4 This embodiment provides a silicon heterojunction solar cell electricity injection system, which includes using the above method to inject electricity into the silicon heterojunction solar cell.

[0047] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the invention.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0049] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Mentioning "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present embodiment application. The appearance of this phrase in various positions in the specification is not necessarily the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0050] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for electrical injection into a silicon heterojunction solar cell, characterized in that: include: Providing a silicon heterojunction cell with seed layers deposited on the front and back sides; A gate line pattern mask layer is formed on the front and back sides of the silicon heterojunction cell, and an intermediate silicon wafer containing gate line grooves is obtained through exposure and development treatment; Placing the intermediate silicon wafer into an electroplating device for electroplating to obtain copper grid lines; Replace the current source on either side of the fixture in the electroplating device so that the fixtures on both sides form positive and negative electrodes; Continuously supplying current for electrical injection to obtain a semi-finished battery; The mask layer and the seed layer on the front and back sides of the semi-finished cell are removed to obtain a finished silicon heterojunction solar cell.

2. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: The electroplating device includes any one of a flying target hanging electroplating fixture, a basket-type electroplating fixture, and a flexible electrode fixture for horizontal electroplating.

3. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: The electroplating device comprises: A first alloy fixture (210) connected to the positive electrode or the negative electrode of a power source; A second alloy clamp (220) is spaced apart from the first alloy clamp (210) and connected to the negative electrode of the power supply; A front clamping plate (110) connected to the first alloy clamp (210), with a front clamping point (130) provided at an end thereof; A back clamp (120) is connected to the second alloy clamp (220), and a back clamp point (140) is provided at the end thereof; the front clamp point (130) and the back clamp point (140) are respectively used to clamp the battery cell (150) to be plated, and the electroplating and electric injection process of the battery cell (150) to be plated is achieved by adjusting the polarity of the power supply connected to the first alloy clamp (210).

4. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: The silicon heterojunction cell has a symmetrical double-sided cell structure, including: The middle is N-type crystalline silicon; The intrinsic amorphous silicon film and the P-type amorphous silicon film are sequentially deposited on the front side to form a PN junction; On the back side, an intrinsic amorphous silicon film and an N-type amorphous silicon film are sequentially deposited to form a back surface field, thereby obtaining a double-sided deposited silicon wafer. Depositing a transparent conductive film on both sides of the silicon wafer after double-sided deposition; Copper electrodes were prepared on TCO thin films.

5. The method for electrical injection into a silicon heterojunction solar cell according to claim 3, characterized in that: The electric injection current range is between 1A and 50A, the power supply is a direct current power supply, and the electric injection time is between 5min and 30min.

6. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: After the copper grid line is obtained, the process also includes water washing and drying, wherein the drying temperature ranges from 80°C to 100°C.

7. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: After the seed layer is obtained, the process further includes secondary washing and secondary drying, wherein the drying temperature ranges from 100°C to 150°C.

8. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: The seed layer includes pure copper and a copper alloy seed layer doped with different metals, wherein the alloy element is selected from at least one of Cu, Ni, Ta, Mo, W, Ti, Cr, Al, Mg, Sn, Zn, and Ag.

9. The method for electrical injection into a silicon heterojunction solar cell according to claim 1, characterized in that: The front main grid width of the copper grid line is 50um~80um, the front sub-grid width is 10um~40um, and the height is 5um~20um; The width of the back main grid is 50um~250um, the width of the back sub grid is 20um~80um; the height is 5um~20um.

10. A silicon heterojunction solar cell electric injection system, characterized in that: The method comprises adopting the method according to any one of claims 1 to 9 to perform electrical injection into a silicon heterojunction solar cell.

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