A method for manufacturing a solar cell and a solar cell

Abstract

The application discloses a preparation method of a solar cell and the solar cell, and relates to the photovoltaic field, and solves the problem that laser slotting is easy to cause damage to a substrate. The preparation method comprises the following steps: manufacturing a metal electrode on a substrate; manufacturing a sacrifice layer on the metal electrode; manufacturing a dielectric material layer on the substrate, the dielectric material layer covering the surfaces of the substrate and the sacrifice layer; and removing the sacrifice layer together with the dielectric material layer covering the sacrifice layer, so that the surface of the metal electrode is exposed. Compared with the prior art of manufacturing a dielectric material layer on a substrate first, then manufacturing a metal electrode after slotting on the dielectric material layer, the method does not need to perform laser slotting above the substrate, and damage to the substrate in the laser slotting process is avoided. The solar cell obtained by the preparation method can avoid or reduce damage to the substrate.

Description

Technical Field

[0001] This invention relates to the field of solar cell manufacturing technology, and in particular to a method for preparing a solar cell and the solar cell itself. Background Technology

[0002] A solar cell is a device that converts light energy into electrical energy. This process involves fabricating conductive electrodes on an absorber substrate (such as silicon) to guide charge carriers and create pathways; this is commonly referred to as cell metallization. There are three main methods for cell metallization: physical plating (such as sputtering, evaporation, and deposition), chemical plating (such as electroless plating and electroplating), and screen printing. Screen printing involves using printing machinery to coat a conductive paste onto the surface of the solar cell, forming fine-line electrodes, which are then dried and sintered to form metal contacts. Due to the simplicity and reliability of screen printing technology, the conductive electrodes of the vast majority of crystalline silicon solar cells worldwide are currently manufactured using screen printing.

[0003] However, with the increasing demands on the precision and materials required for metal electrode fabrication in solar cells, screen printing is no longer sufficient. Currently, laser grooving is increasingly being used. This involves laser-grooving the dielectric layer of the substrate to create grid patterns that match the electrode design, and then forming metal electrodes on the substrate through physical or chemical plating. The problems with this laser grooving method are twofold: firstly, it requires highly precise process control. On one hand, the laser process needs to be designed for different materials, structures, and thicknesses of the dielectric layer used for passivation and anti-reflection functions. If the dielectric layer material, structure, or thickness changes, the process needs to be redeveloped, making the technology complex and intolerant. Secondly, laser grooving requires precise control of the grooving depth, which is difficult to master and can easily lead to damage to the substrate after the laser penetrates the dielectric layer. Additionally, screen printing also uses burn-through pastes; however, burn-through pastes also have their limitations, as they can continue to burn through the dielectric layer and damage the substrate. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a solar cell, so as to avoid or reduce damage to the substrate.

[0005] In a first aspect, the present invention provides a method for preparing a solar cell, the method comprising:

[0006] Fabricate metal electrodes on a substrate;

[0007] A sacrificial layer is fabricated on the metal electrode;

[0008] A dielectric material layer is fabricated on a substrate, and the dielectric material layer covers the surface of the substrate sacrificial layer;

[0009] Remove the sacrificial layer to remove the dielectric material layer covering it, exposing the surface of the metal electrode.

[0010] When using the above technical solution, a metal electrode is first fabricated on the substrate, then a sacrificial layer is fabricated on the metal electrode, and then a dielectric material layer is fabricated on the substrate, covering the surfaces of the substrate and the sacrificial layer. Finally, the sacrificial layer is removed to remove the dielectric material layer covering it, exposing the surface of the metal electrode. Since the sacrificial layer facilitates separation, it is positioned between the metal electrode and the dielectric material layer, allowing for easy separation of the dielectric material layer from the metal electrode and exposing its surface. Compared to existing methods that first fabricate a dielectric material layer on the substrate and then create grooves in the dielectric material layer before fabricating the metal electrode, the method in this invention does not require laser grooving or paste burning through the dielectric layer above the substrate. This simplifies the process by eliminating the need to design laser processes for different materials, structures, and thicknesses of the dielectric material layer on the substrate, and avoids damage to the substrate during laser grooving. Therefore, damage to the substrate is avoided or reduced.

[0011] Optionally, in the above-described fabrication method, a metal electrode is fabricated on a substrate, and a sacrificial layer is fabricated on the metal electrode. Specifically, a patterned mask is fixed to the substrate; a metal film is deposited on the substrate with the mask fixed, and then a sacrificial layer is fabricated; the mask is removed to peel the metal film and sacrificial layer covering the mask together from the substrate, leaving the sacrificial layer covering the surface of the metal film. Thus, when fabricating the metal electrode, a pattern matching the shape of the metal electrode is first fabricated on the mask, the patterned mask is then fixed to the substrate, and a metal film is deposited on the substrate with the mask fixed to form the metal electrode. Since the mask is pre-patterned, the patterning process does not need to be performed on the substrate, avoiding damage to the substrate. Removing the mask peels the metal film and sacrificial layer covering the mask together from the substrate, leaving the sacrificial layer covering the surface of the metal electrode. Thus, when fabricating the sacrificial layer, it can be fabricated on the entire surface, rather than only on the metal electrode, thereby simplifying the sacrificial layer fabrication process. In other words, there is no need to prepare a patterned sacrificial layer separately. The sacrificial layer can be prepared incidentally after the metal film is deposited, and then the mask is removed, thus forming both the patterned metal electrode and the patterned sacrificial layer at the same time.

[0012] Optionally, in the above preparation method, the sacrificial layer is removed by one or more of the following methods: washing with water, irradiation, and heating. Depending on the material of the sacrificial layer, a suitable removal method can be selected, such as one or more of the following methods: washing with water, irradiation, and heating.

[0013] Optionally, in the above preparation method, a sacrificial layer is fabricated on the mask for depositing the metal film, specifically by coating or attaching a sacrificial layer to the mask for depositing the metal film; the thickness of the sacrificial layer is 15 nm to 10 μm. Thus, the method of fabricating the sacrificial layer can be selected according to actual needs.

[0014] Optionally, in the above preparation method, the sacrificial layer is a water-soluble material; the water-soluble material is selected from NaCl and KCl; or, the sacrificial layer is an organic material; the organic material is selected from one or more of polyvinyl alcohol and polyvinylpyrrolidone. Thus, if the sacrificial layer is a water-soluble material, it can be dissolved by washing with water, facilitating the removal of the dielectric material layer. If the sacrificial layer is an organic material, it can be removed by washing with water, light irradiation, or heating, facilitating the removal of the dielectric material layer.

[0015] Optionally, in the above preparation method, metal electrodes and dielectric material layers are fabricated on the substrate by physical vapor deposition or chemical vapor deposition.

[0016] Optionally, in the above preparation method, the dielectric material layer is selected from one or more combinations of alumina, silicon oxide, silicon nitride, silicon carbide, amorphous silicon, and microcrystalline silicon.

[0017] Optionally, in the above-described fabrication method, the substrate fabrication process includes: providing a silicon substrate; and fabricating one or more combinations of a doped layer, a passivation layer, a tunneling layer, and a selective contact dielectric layer on at least one side surface of the silicon substrate. Thus, different substrates can be used in the present invention for fabricating electrodes first and then the dielectric material layer, resulting in a wide range of applications.

[0018] Optionally, in the above preparation method, the solar cell is a TOPCON cell.

[0019] Secondly, the present invention also provides a solar cell obtained by any of the preparation methods described above. Compared with the prior art, the beneficial effects of the solar cell provided by the present invention are the same as those of the preparation methods of the solar cells described above, and will not be repeated here. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of a mask in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure for fixing a mask onto a substrate in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of forming a metal electrode by depositing a metal film on a mask in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure for fabricating a sacrificial layer on a mask and a metal electrode in an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the structure for removing the mask and the sacrificial layer on the mask in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of fabricating a dielectric material layer on a substrate and metal electrodes in an embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of the structure for removing the sacrificial layer and dielectric material layer covering the metal electrode in an embodiment of the present invention;

[0028] Figure 8 This is a schematic flowchart of a method for preparing a solar cell according to an embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the specific process of step S100 in a method for preparing a solar cell according to an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram of step S200 of a method for preparing a solar cell according to an embodiment of the present invention.

[0031] Reference numerals: 1-substrate, 2-mask, 21-gate trench, 3-metal electrode, 4-sacrificial layer, 5-dielectric material layer. Detailed Implementation

[0032] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0033] In the photovoltaic field, solar cells convert solar energy into electrical energy, making them an important source of clean energy. Electrodes are key components of solar cells, primarily consisting of an array grid structure. Traditional methods for preparing solar cell electrodes commonly employ screen printing of silver paste, where conductive paste is applied to the surface of the solar cell using printing machinery to form fine-line electrodes, which are then dried and sintered to form metal contacts. However, problems such as insufficient paste and peripheral seepage can easily occur when the conductive paste enters the grid grooves, resulting in incomplete electrodes or burrs. Furthermore, screen printing has limitations in terms of paste requirements; to ensure a firm print, other viscous materials need to be added, leading to low metal purity in the electrodes and affecting conductivity. Typically, only materials like silver paste and aluminum paste can be used. With the increasing demands for precision and materials in solar cell electrode fabrication, screen printing is no longer sufficient. Therefore, laser grooving technology is increasingly being adopted. Laser grooving involves first creating a dielectric layer on the substrate, then using a laser to create grid grooves on the dielectric layer that match the electrode pattern. Finally, metal electrodes are formed on the substrate through physical or chemical plating. The problems with this laser grooving method for electrode fabrication are twofold. Firstly, laser grooving requires highly precise process control. On one hand, the laser process needs to be designed for different materials, structures, and thicknesses of the dielectric layer used for passivation and anti-reflection functions on the substrate. If the dielectric layer material, structure, or thickness changes, the process needs to be redeveloped, making the technology complex and intolerant. Secondly, laser grooving requires precise control of the grooving depth, which is difficult to master and can easily lead to damage to the substrate after the laser penetrates the dielectric layer. Additionally, screen printing processes also use burn-through pastes; however, burn-through pastes also have their limitations, as they can continue to burn downwards after burning through the dielectric layer, damaging the substrate.

[0034] Therefore, to resolve the above issues, please refer to [link / reference needed]. Figures 1-8 This invention provides a method for fabricating a solar cell, applicable to the fabrication of various solar cells, such as crystalline silicon solar cells, perovskite solar cells, tandem solar cells, and solar cells with doped layers or TCO thin films. The method includes the following steps:

[0035] Step S100: Fabricate metal electrodes 3 on substrate 1;

[0036] Step S200: A sacrificial layer 4 is fabricated on the metal electrode 3;

[0037] Step S300: A dielectric material layer 5 is fabricated on the substrate 1, and the dielectric material layer 5 covers the surfaces of the substrate 1 and the sacrificial layer 4.

[0038] Step S400: Remove the sacrificial layer 4 to remove the dielectric material layer 5 covering the sacrificial layer 4, thereby exposing the surface of the metal electrode 3.

[0039] When using the above technical solution, a metal electrode 3 is first fabricated on the substrate 1, then a sacrificial layer 4 is fabricated on the metal electrode 3, and then a dielectric material layer 5 is fabricated on the substrate 1, covering the surfaces of the substrate 1 and the sacrificial layer 4. Finally, the sacrificial layer 4 is removed, along with the dielectric material layer 5 covering it, exposing the surface of the metal electrode 3. Since the function of the sacrificial layer 4 is easy to separate, it is positioned between the metal electrode 3 and the dielectric material layer 5. The dielectric material layer 5 does not directly cover the metal electrode 3. When the sacrificial layer 4 separates from the metal electrode 3, there is no bonding force between the dielectric material layer 5 and the metal electrode 3, allowing for easy separation of the dielectric material layer 5 from the metal electrode 3 and exposing the surface of the metal electrode 3. Compared to existing methods that first fabricate a dielectric material layer on a substrate and then create grooves in the dielectric material layer to fabricate metal electrodes, the method in this invention first fabricates the metal electrodes 3 on the substrate 1 and then creates a sacrificial layer 4 on the metal electrodes 3. Therefore, after fabricating the dielectric material layer 5, there is no need to perform a laser grooving step to create grid grooves on the dielectric material layer 5. Thus, the method in this invention avoids laser grooving or paste burning through the dielectric layer above the substrate 1. This simplifies the process by eliminating the need to design laser processes for different materials, structures, and thicknesses of the dielectric material layer 5 on the substrate 1, and also prevents damage to the substrate 1 during the laser grooving process. Therefore, damage to the substrate 1 is avoided or reduced.

[0040] like Figures 1-6 , Figure 9 and Figure 10 As shown, further, in this embodiment, a metal electrode 3 is fabricated on the substrate 1, and a sacrificial layer 4 is fabricated on the metal electrode, specifically including the following steps:

[0041] Step S101, as follows Figure 1 and Figure 2 As shown, the patterned mask 2 is fixed to the substrate 1, that is, a grid groove 21 matching the shape of the metal electrode 3 is pre-fabricated on the mask 2. The mask 2 can be a polymer film, specifically made of polyethylene terephthalate (PET), polyolefin film (PO), polyimide (PI), polyvinyl chloride (PVC), or other polymer films with sufficient thickness. The polymer film can be a non-adhesive film or an adhesive film, i.e., commonly known as adhesive tape. Patterning can be achieved by laser cutting. The mask 2 can be fixed to the substrate 1 using one or more of the following methods in combination: double-sided tape, adhesive, fixing slots, and a substrate stage. If the mask 2 uses adhesive tape, the fixing method can be direct bonding.

[0042] Step S102, as follows Figure 3As shown, a metal film is deposited on a substrate 1 with a fixed mask 2 to form a metal electrode 3 on the substrate 1. Specifically, physical deposition methods or chemical deposition methods can be used, such as physical vapor deposition (PVD), chemical vapor deposition, electroplating, etc. PVD includes vacuum evaporation, sputtering, ion plating, etc. When depositing a metal film on the mask using PVD, a single PVD process or a combination of several PVD processes can be used. Compared with the traditional screen printing process, the deposition method for preparing the metal electrode 3 has higher preparation precision, a wider range of selectable metal materials, higher metal purity, and improved conductivity. One or more metals can be used to simultaneously prepare the metal electrode, reducing material limitations.

[0043] Step S201, as follows Figure 4 As shown, a sacrificial layer 4 is fabricated on the mask 2 where the metal film is deposited. The sacrificial layer 4 at least covers the metal electrode 3. The sacrificial layer 4 is characterized by its ease of separation from the object surface. It is positioned between two object layers, enabling the upper object to be separated from the lower object surface. To facilitate the fabrication of the sacrificial layer 4, it covers the entire surface of both the mask 2 and the metal electrode 3.

[0044] Step S202, as follows Figure 5 As shown, the mask is removed, and the metal film and sacrificial layer 4 covering the mask 2 are peeled off from the substrate 1 together, leaving the sacrificial layer 4 covering the surface of the metal electrode 3. Since the function of the mask 2 is only to fabricate the metal electrode 3 on the substrate 1, the mask 2 can be peeled off from the substrate 1 after the metal electrode 3 is formed on the substrate 1. When fabricating the sacrificial layer 4, part or all of the surface of the mask 2 is covered by the sacrificial layer 4. Therefore, when the mask 2 is peeled off from the substrate 1, the sacrificial layer 4 on the mask 2 is also peeled off together, leaving only the sacrificial layer 4 on the surface of the metal electrode 3.

[0045] Using this method, since the mask 2 is pre-patterned, the patterning process does not need to be performed on the substrate 1, avoiding damage to the substrate 1. The mask 2 is removed to peel the metal film and sacrificial layer 4 covering the mask 2 from the substrate 1 together, leaving the sacrificial layer covering the surface of the metal electrode 3. Thus, when fabricating the sacrificial layer 4, it can be fabricated on the entire surface, not just on the metal electrode 3, simplifying the fabrication process of the sacrificial layer 4. In other words, there is no need to separately prepare the patterned sacrificial layer 4; it can be prepared incidentally after depositing the metal film, and then the mask 2 is removed, thus simultaneously forming the patterned metal electrode 3 and the patterned sacrificial layer 4. After the metal electrode 3 is fabricated on the substrate 1, the dielectric material layer 5 is then fabricated. At this point, laser grooving of the dielectric material layer 5 is not required; only the dielectric material layer 5 covering the metal electrode 3 needs to be removed.

[0046] Of course, another method for fabricating the metal electrode 3 on the substrate 1 is to fix a metal mask on the substrate 1, deposit a metal film on the metal mask using a deposition method, and form the metal electrode on the substrate 1.

[0047] In the method of fabricating metal electrodes using a metal mask, a sacrificial layer 4 can be fabricated on the metal mask, covering the metal mask and the metal electrode 3. Then, the metal mask and the sacrificial layer 4 on the metal mask are removed from the substrate 1, leaving only the sacrificial layer 4 on the surface of the metal electrode 3.

[0048] Furthermore, in this embodiment, the sacrificial layer 4 is removed by one or more of the following methods: washing, light irradiation, and heating. The appropriate removal method is selected based on the material of the sacrificial layer 4, ensuring that the removal process does not damage the metal electrode 3 or the dielectric material layer 5 on the substrate 1. For example, during washing, the sacrificial layer 4 can dissolve in water or other liquids, eliminating the bonding force between the metal electrode 3 and the dielectric material layer 5, thus allowing the dielectric material layer 5 to detach from the metal electrode 3. During light irradiation, the sacrificial layer 4 undergoes physical changes, such as melting, volatilization, or reduced viscosity, resulting in a lack of or reduced bonding force between the metal electrode 3 and the dielectric material layer 5, facilitating the detachment of the dielectric material layer 5 from the metal electrode 3. During heating, the sacrificial layer 4 undergoes physical changes, such as melting, volatilization, or reduced viscosity, resulting in a lack of or reduced bonding force between the metal electrode 3 and the dielectric material layer 5, facilitating the detachment of the dielectric material layer 5 from the metal electrode.

[0049] In this embodiment, the sacrificial layer 4 is a water-soluble material or an organic material. Water-soluble materials are soluble in water and can therefore be removed by washing. The water-soluble material can be coated onto the surfaces of the mask 2 and the metal electrode 3. For example, when the water-soluble material is NaCl or KCl, a high-concentration sodium chloride solution (NaCl) or a high-concentration potassium chloride solution (KCl) can be coated onto the surfaces of the mask 2 and the metal electrode 3, and after drying, the sacrificial layer 4 is formed. When the water-soluble material is NaCl or KCl, the contamination caused after cleaning can be reduced.

[0050] The sacrificial layer 4 of organic material can be washed with water or undergo physical changes under light or heat, such as melting, volatilization, or reduced viscosity. Therefore, it can be removed by light or heat. The sacrificial layer 4 of organic material can be in the form of a solid thin layer, which can be applied to the surfaces of the mask 2 and the metal electrode 3 by adhesive bonding. Alternatively, the organic material can be in the form of a liquid paste, which can be coated onto the surfaces of the mask 2 and the metal electrode 3 and dried to form the sacrificial layer 4. Specifically, the sacrificial layer 4 of organic material can be polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP), both of which have good water solubility and can be removed by washing with water.

[0051] In this embodiment, the step S201 of fabricating the sacrificial layer 4 on the metallized mask 2 specifically involves coating or attaching the sacrificial layer 4 onto the metallized mask 2. The thickness of the sacrificial layer is 15 nm to 10 μm, preferably 50 nm to 2 μm. A suitable fabrication method for the sacrificial layer 4 is selected based on its material. Of course, the sacrificial layer 4 can also be fabricated using other methods, such as deposition, as long as it facilitates subsequent removal of the sacrificial layer 4; it is not limited to the methods listed in this embodiment.

[0052] In this embodiment, a metal electrode 3 and a dielectric material layer 5 are fabricated on a substrate 1 using either physical vapor deposition (PVD) or chemical vapor deposition (CVD). PVD methods include vacuum evaporation, sputtering, and ion plating. When depositing the metal electrode 3 and the dielectric material layer 5 on the substrate 1 and the metal electrode 3 using PVD, a single PVD process or a combination of several PVD processes can be employed. When a metal film is deposited on a mask 2 using PVD in step S102 to form the metal electrode 3 on the substrate 1, the dielectric material layer 5 can be fabricated on the substrate 1 and the metal electrode 3 using the same method as for fabricating the metal electrode 3 after the mask 2 is peeled off from the substrate 1. This simplifies the equipment required for the process and makes the operation more seamless.

[0053] Chemical vapor deposition (CVD) can also be used to fabricate dielectric material layer 5 on substrate 1 and metal electrode 3. The appropriate method can be selected based on the material of dielectric material layer 5 and the requirements of the preceding and following processes.

[0054] Specifically, in this embodiment, the dielectric material layer 5 can be a passivation layer or an antireflection layer, and the specific material can be selected from one or more combinations of alumina, silicon oxide, silicon nitride, silicon carbide, amorphous silicon, and microcrystalline silicon.

[0055] In this embodiment, the fabrication process of substrate 1 includes: providing a silicon substrate; and fabricating one or more combinations of a doped layer, a passivation layer, a tunneling layer, and a selective contact dielectric layer on at least one side surface of the silicon substrate. That is, any one of the above thin layers can be fabricated individually, or multiple layers can be stacked sequentially. Specifically, the appropriate thin layers are selected based on the type of substrate 1, and these thin layers are all fabricated on the silicon substrate before the metal electrode 3 is fabricated. Thus, different substrates can be used in this invention to fabricate electrodes first and then the dielectric material layer, resulting in a wide range of applications. The material of the selective contact dielectric layer can be one or more combinations of MoO3, V2O3, WO3, Ta2O5, TiO2, ZnO, and In2O3; the passivation layer can be one or more combinations of alumina, silicon oxide, silicon nitride, and silicon carbide; and the doped layer can be one or more combinations of polycrystalline silicon, amorphous silicon, and microcrystalline silicon.

[0056] Taking a TOPCon structure battery as an example, since the metal electrode cannot penetrate the tunneling layer and the doped polysilicon layer to avoid leakage current, the doped polysilicon layer is often made very thick in the printing process to prevent the metal electrode from penetrating it, which affects light transmittance and production efficiency. If the existing method of first making the dielectric material layer and then the metal electrode is used, a laser is needed to make very deep trenches in the dielectric material layer on the substrate, and it is difficult to control the trench depth well, which easily penetrates the doped polysilicon layer. Alternatively, a burn-through paste can be used, which also easily burns through the doped polysilicon layer. However, using the fabrication method of this invention, by fixing a pre-patterned mask on the substrate 1 and selecting a mask 2 with a suitable slit width and thickness, not only can a finer and taller electrode morphology be obtained during the subsequent deposition of the metal electrode 3, but also precise contact between the metal electrode and the doped polysilicon layer can be achieved, reducing the thickness and ultimately improving the battery efficiency.

[0057] Based on the solar cell fabrication method described in any of the above embodiments, this invention also provides a solar cell obtained by the fabrication method described in any of the above embodiments.

[0058] Since the solar cell is obtained using the solar cell fabrication method of this invention, compared to existing methods that first fabricate a dielectric material layer on a substrate and then create metal electrodes by slotting the dielectric material layer, the method of this invention first fabricates the metal electrodes 3 on the substrate 1. Therefore, after fabricating the dielectric material layer 5, it is not necessary to perform a laser slotting step on the dielectric material layer 5 to create the grid grooves. Thus, the method of this invention does not involve laser slotting on the substrate 1. On the one hand, it eliminates the need to design laser processes for different materials, structures, and thicknesses of the dielectric material layer 5 on the substrate 1, simplifying the process. On the other hand, it avoids damage to the substrate 1 during the laser slotting process. Therefore, damage to the substrate 1 is avoided or reduced, improving the quality and yield of the solar cell.

[0059] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0060] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a solar cell, characterized in that, The method includes: Fabricate metal electrodes on a substrate; A sacrificial layer is formed on the metal electrode; A dielectric material layer is formed on the substrate, the dielectric material layer covering the surfaces of the substrate and the sacrificial layer; Remove the sacrificial layer to remove the dielectric material layer covering the sacrificial layer, thereby exposing the surface of the metal electrode.

2. The preparation method according to claim 1, characterized in that, The metal electrode is fabricated on the substrate, and a sacrificial layer is fabricated on the metal electrode; Specifically: A patterned mask is fixed to the substrate; A metal film is deposited on a substrate to which the mask is fixed, and then the sacrificial layer is fabricated. Remove the mask to peel the metal film and the sacrificial layer covering the mask from the substrate together, leaving the sacrificial layer covering the surface of the metal film.

3. The preparation method according to claim 1, characterized in that, The sacrificial layer is removed by one or more of the following methods: washing, light exposure, and heating.

4. The preparation method according to claim 2, characterized in that, The creation of the sacrificial layer specifically involves: A sacrificial layer is coated or adhered onto the mask on which the metal film is deposited; the thickness of the sacrificial layer is 15 nm to 10 μm.

5. The preparation method according to any one of claims 1-2, characterized in that, The sacrificial layer is a water-soluble material; the water-soluble material is selected from NaCl and KCl; Alternatively, the sacrificial layer may be an organic material; the organic material may be selected from one or more of polyvinyl alcohol and polyvinylpyrrolidone.

6. The preparation method according to any one of claims 1-3, characterized in that, The metal electrode and the dielectric material layer are fabricated on the substrate using physical vapor deposition or chemical vapor deposition.

7. The preparation method according to any one of claims 1-3, characterized in that, The dielectric material layer is selected from one or more combinations of alumina, silicon oxide, silicon nitride, silicon carbide, amorphous silicon, and microcrystalline silicon.

8. The preparation method according to any one of claims 1-3, characterized in that, The substrate fabrication process includes: Provide a silicon substrate; One or more combinations of a doped layer, a passivation layer, a tunneling layer, and a selective contact dielectric layer are formed on at least one side surface of the silicon substrate.

9. The preparation method according to any one of claims 1-3, characterized in that, The solar cell is a TOPCON cell.

10. A solar cell, characterized in that, The solar cell is obtained by the preparation method according to any one of claims 1-9.

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