Solar cell manufacturing method and solar cell

Abstract

The present application relates to a solar cell manufacturing method and a solar cell. The solar cell manufacturing method comprises: providing a substrate; forming an initial absorption layer on the substrate by a solution method; coating the initial absorption layer with a first solution; and curing and sintering the substrate having been coated with the first solution, so that the initial absorption layer forms a first cell absorber layer, and the first solution forms an electron transport layer. The present application can effectively improve an electron transport rate between the first cell absorber layer and the electron transport layer.

Description

Methods for preparing solar cells and solar cells Technical Field

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

[0002] Perovskite / silicon tandem solar cells are devices that directly convert solar energy into electrical energy. With their high photoelectric conversion efficiency, environmental friendliness, and wide range of applications, perovskite / silicon tandem solar cells have broad application prospects in modern society. A perovskite solar cell includes an absorber layer and an electron transport layer. The absorber layer absorbs sunlight and converts it into electrical energy. The electron transport layer transports photogenerated electrons from the absorber layer to the external circuit while preventing electron-hole recombination. Current technologies often use C60 and its derivatives as materials for the electron transport layer, but these are expensive. Furthermore, the low raw material utilization rate (10-30%) during the deposition process using vacuum evaporation further increases production costs. In addition, C60 material has poor adhesion to the ITO layer and is extremely prone to delamination, hindering charge transport.

[0003] Therefore, the process for fabricating perovskite cells in perovskite / silicon tandem solar cells still needs improvement. Summary of the Invention

[0004] Based on this, this application provides a method for preparing a solar cell that can improve the electron transport rate, as well as the solar cell itself.

[0005] A method for fabricating a solar cell, comprising:

[0006] Provide a base;

[0007] An initial absorption layer is formed on the substrate using a solution method;

[0008] A first solution is coated onto the initial absorption layer;

[0009] The substrate coated with the first solution is cured and sintered so that the initial absorption layer forms the first battery absorption layer and the first solution forms the electron transport layer.

[0010] In one embodiment, the first battery absorber layer comprises a perovskite layer, the electron transport layer comprises a tin oxide layer, and the solvent in the first solution is an organic solvent.

[0011] In one embodiment, prior to coating the initial absorbent layer with the first solution, the method further includes:

[0012] The initial absorption layer is pre-sintered, and the pre-sintering time is shorter than the curing sintering time.

[0013] In one embodiment, forming an initial absorption layer on the substrate using a solution method includes:

[0014] A second solution is coated onto the substrate;

[0015] The solvent is extracted from the second solution to form an initial absorption layer.

[0016] In one embodiment, prior to sintering the substrate coated with the first solution, the method further includes:

[0017] The solvent is extracted from the first solution to form an initial electron transport layer.

[0018] In one embodiment, the first solution includes a first additive and / or a second additive, the first additive being used to promote the crystallization of the first battery absorber layer, and the second additive being used to chemically passivate the first battery absorber layer.

[0019] In one embodiment, prior to coating the initial absorbent layer with the first solution, the method further includes:

[0020] A passivation layer is formed on the initial absorption layer.

[0021] In one embodiment, the provided substrate includes:

[0022] Provide semiconductor substrates;

[0023] A second battery structure is formed based on the semiconductor substrate;

[0024] An intermediate layer is formed on the front side of the second battery structure;

[0025] At least one hole transport layer is formed on the intermediate layer.

[0026] In one embodiment, after forming the second battery structure based on the semiconductor substrate, the method further includes:

[0027] A first transparent conductive layer is formed on the back side of the second battery structure, and the first transparent conductive layer and the intermediate layer are respectively located on opposite sides of the second battery structure.

[0028] The substrate coated with the first solution is then cured and sintered to form a first battery absorption layer from the initial absorption layer. After the first solution forms an electron transport layer, the process further includes:

[0029] A second transparent conductive layer is formed on the electron transport layer;

[0030] A first electrode is formed on the second transparent conductive layer;

[0031] A second electrode is formed on the first transparent conductive layer.

[0032] A solar cell is prepared according to any one of the above methods.

[0033] The aforementioned method for fabricating solar cells first involves forming an initial absorption layer on a substrate using a solution method, then coating the initial absorption layer with a first solution, and finally sintering the substrate after coating with the first solution to simultaneously form a first cell absorption layer and an electron transport layer. Therefore, this application allows for better contact and bonding between the first cell absorption layer and the electron transport layer, thereby effectively improving the electron transport rate between them. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 is a flowchart of a method for fabricating a solar cell provided in one embodiment;

[0036] Figure 2 is a flowchart of a method for fabricating a solar cell provided in another embodiment;

[0037] Figure 3 is a flowchart of a method for fabricating a solar cell provided in another embodiment;

[0038] Figure 4 is a flowchart of a method for fabricating a solar cell provided in another embodiment;

[0039] Figure 5 is a schematic diagram of the cross-sectional structure of a solar cell provided in another embodiment.

[0040] 100 - Substrate, 110 - Second cell structure, 111 - Semiconductor substrate, 112 - First intrinsic amorphous silicon layer, 113 - Second intrinsic amorphous silicon, 114 - p-type doped layer, 115 - n-type doped layer, 120 - Intermediate layer, 130 - First transparent conductive layer, 140 - Hole transport layer, 200 - Absorption layer, 300 - Electron transport layer, 400 - Second transparent conductive layer, 500 - First electrode, 600 - Second electrode. Detailed Implementation

[0041] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0043] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this application, the first element, part, region, layer, doping type, or portion discussed below may be referred to as a second element, part, region, layer, or portion.

[0044] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0045] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0046] In one embodiment, referring to Figures 1 and 5, a method for fabricating a solar cell is provided, comprising the following steps:

[0047] Step S10: Provide substrate 100.

[0048] The substrate 100 may include a substrate. The substrate may be used to support the solar cell.

[0049] Step S20: An initial absorption layer is formed on the substrate 100 by a solution method.

[0050] The initial absorption layer can be an absorption layer 200 that has a certain cured state but still contains some solvent and is not completely dried and cured.

[0051] Step S50: Coat the initial absorption layer with the first solution.

[0052] The first solution is a solution used to form the electron transport layer 300.

[0053] The solute in the first solution may include the electron transport layer 300 material itself. However, the form of the first solution is not limited to this. The first solution may also include a precursor for forming the electron transport layer 300, which can be specifically configured according to actual needs.

[0054] The coating method for the first solution can be, but is not limited to, spraying, inkjet printing, slot coating, roller coating, etc.

[0055] In step S70, the substrate 100 coated with the first solution is sintered so that the initial absorption layer forms the first battery absorption layer 200 and the first solution forms the electron transport layer 300.

[0056] At this point, the first battery absorber layer 200 and the electron transport layer 300 are sintered simultaneously. It can be understood that the first battery absorber layer 200 is the absorber layer 200 of the first battery structure. The solar cell can be a tandem cell including the first battery structure, or a single-layer cell including the first battery structure, depending on actual needs.

[0057] In this embodiment, an initial absorption layer is first formed on the substrate 100 using a solution method. Then, a first solution is coated onto the initial absorption layer. The substrate 100 after coating with the first solution is then sintered, thereby simultaneously forming a first battery absorption layer 200 and an electron transport layer 300. Therefore, this embodiment allows for better contact and bonding between the first battery absorption layer 200 and the electron transport layer 300, thereby effectively improving the electron transport rate between them.

[0058] In one embodiment, the first battery absorber layer 200 comprises a perovskite layer. The electron transport layer 300 comprises a tin oxide layer, and the solvent in the first solution is an organic solvent.

[0059] At this point, as an example, step S50, coating the initial absorption layer with the first solution, includes:

[0060] A solution of tin oxide nanopowder was coated onto the initial absorption layer.

[0061] Specifically, tin oxide can first be made into nanoparticles and dispersed in organic solvents such as alcohol, isopropanol, and dibutanol to form a tin oxide nanoparticle solution.

[0062] Then, tin oxide nanopowder solution can be coated onto the surface of the initial absorption layer using processes such as spin coating, slot coating, spraying, inkjet printing, and roller coating.

[0063] At this point, the tin oxide nanoparticles in the first solution can be prepared separately without considering the chemical stability of the perovskite. Therefore, high-quality tin oxide materials that meet the requirements of electron transport layer 300 can be prepared.

[0064] In this embodiment, a tin oxide layer is used as the electron transport layer 300. The solvent of the first solution is an organic solvent that does not react with perovskite, thus preventing perovskite decomposition. Simultaneously, tin oxide has a low cost, significantly reducing production costs. Preparing the tin oxide layer as the electron transport layer 300 using a solution method results in high material utilization, thereby greatly saving raw materials. Furthermore, tin oxide has high transmittance, allowing more light to enter the perovskite layer (first cell absorption layer 200), improving the solar energy utilization rate of the solar cell and thus increasing power generation efficiency.

[0065] In one embodiment, referring to Figure 2, before step S50, the following is also included:

[0066] Step S30: Pre-sinter the initial absorption layer, and the pre-sintering time is shorter than the curing sintering time.

[0067] The pre-sintering time is shorter than the curing sintering time in step S70, thereby preventing the initial absorption layer from being completely dried and cured.

[0068] As an example, the pre-sintering time can be 4-6 minutes. The curing sintering time can be 18-22 minutes. Specifically, the pre-sintering time is, for example, 5 minutes. The curing sintering time is, for example, 20 minutes.

[0069] As an example, the sintering temperature during pre-sintering can also be less than or equal to the sintering temperature during curing sintering, thereby further preventing the initial absorption layer from being completely dried and cured.

[0070] The sintering temperature during pre-sintering can be 70℃-80℃. The sintering temperature during curing sintering can be 120℃-180℃, for example, 150℃.

[0071] In this embodiment, the initial absorption layer is preferably pre-sintered to ensure that it has a good preliminary morphology. This prevents excessive material diffusion between the initial absorption layer and the initial electron transport layer before simultaneous sintering, thus facilitating the formation of a separate and independent first battery absorption layer 200 and electron transport layer 300.

[0072] Of course, in other embodiments, when a suitable process can ensure that the initial absorption layer formed in step S20 has a sufficient solidified and shaped form, step S30 may be omitted. The specific steps can be set according to actual needs.

[0073] In one embodiment, step S20 includes:

[0074] Step S21: Coat the second solution onto the substrate 100.

[0075] The second solution is used to form the absorber layer 200. The solute in the second solution may include the precursor used to form the absorber layer 200, or it may include the absorber layer 200 material itself, depending on actual needs.

[0076] Step S22: Extract the solvent from the second solution to form the initial absorption layer.

[0077] Most of the solvent in the second solution can be extracted by methods such as antisolvent extraction, air knife drying, or vacuum drying, thereby forming the initial absorption layer.

[0078] When the solute in the second solution includes a precursor for forming the absorbent layer 200, during the extraction of the solvent from the second solution, suitable conditions can be provided simultaneously to allow the precursor of the absorbent layer 200 to react and form the absorbent layer 200 material, thereby forming the initial absorbent layer.

[0079] As an example, the first battery absorber layer 200 includes a perovskite layer, and the second solution may include a precursor solution of the perovskite layer, that is, the solute of the second solution includes a precursor for forming the perovskite layer.

[0080] At this point, in step S22, during the process of removing the solvent from the precursor solution of the perovskite layer, appropriate conditions can be provided to promote the reaction of the precursor solution of the perovskite layer to form perovskite material, thereby forming an initial absorption layer.

[0081] In one embodiment, referring to Figure 3, before step S70, the following steps are also included:

[0082] Step S60: Extract the solvent from the first solution to form an initial electron transport layer.

[0083] The initial electron transport layer can be an electron transport layer 300 that has a certain cured state but still contains some solvent and is not completely dried and cured.

[0084] Most of the solvent in the first solution can be extracted by methods such as antisolvent extraction, air knife drying, or vacuum drying, thereby forming the initial electron transport layer.

[0085] When the solute in the first solution includes a precursor for forming the electron transport layer 300, appropriate conditions can be provided simultaneously during the extraction of the solvent from the first solution to allow the precursor of the electron transport layer 300 to react and form the electron transport layer 300 material, thereby forming the initial electron transport layer.

[0086] Subsequently, in step S70, when sintering the substrate 100 coated with the first solution, specifically, the initial absorption layer and the initial electron transport layer can be sintered simultaneously, with the initial absorption layer forming the first battery absorption layer 200 and the initial electron transport layer forming the electron transport layer 300.

[0087] Of course, in other embodiments, the solvent in the first solution can also be a more volatile solvent. In this case, after step S50, step S70 can be executed directly, so that the first solution is directly sintered to form the electron transport layer 300.

[0088] In one embodiment, the first solution includes a first additive and / or a second additive.

[0089] The first additive is used to promote the crystallization of the first battery absorber layer 200.

[0090] As an example, the first battery absorber layer 200 includes a perovskite layer, and the first solution includes a tin oxide nanopowder solution.

[0091] At this point, a first additive that promotes the crystallization of the perovskite layer can be added to the tin oxide nanopowder solution. This first additive may include, but is not limited to, any one or more of MACl, KCl, RbCl, potassium acetate, methylamine acetate, and rubidium acetate.

[0092] The first additive can promote the crystallization of the first battery absorber layer 200, thereby improving the crystallization quality of the first battery absorber layer 200. Furthermore, during the curing and sintering process in step S70, the first additive can diffuse better into the initial absorption layer, which is even more conducive to improving the crystallization quality of the first battery absorber layer 200.

[0093] The second additive is used to chemically passivate the first battery absorber layer 200, thereby reducing defects within the first battery absorber layer 200. Specifically, the second additive includes chlorides, iodides, bromides, etc.

[0094] Specifically, when the first solution includes a second additive, the second additive can diffuse during the curing and sintering process in step S70. The second additive diffused into the first battery absorber layer 200 can perform bulk passivation on the first battery absorber layer 200, and the second additive diffused into the interface between the first battery absorber layer 200 and the electron transport layer 300 can perform interface passivation on the first battery absorber layer 200, thereby effectively reducing crystallization defects in the first battery absorber layer 200.

[0095] In one embodiment, referring to Figure 4, before step S50, the following may also be included:

[0096] Step S40: A passivation layer is formed on the initial absorption layer.

[0097] At this point, in step S50, the first solution can be coated onto the surface of the passivation layer.

[0098] The passivation layer can have a small thickness, such as no more than 1 nm, so as not to affect the electron transport between the first battery absorption layer 200 and the electron transport layer 300.

[0099] The passivation layer may include a field passivation layer, a chemical passivation layer, or a dual passivation layer formed by stacked field passivation layers and chemical passivation layers.

[0100] The field passivation layer can transport electrons and reflect holes back, thereby reducing carrier recombination and improving photoelectric conversion efficiency. The material of the field passivation layer can include, but is not limited to, LiF or MgFx.

[0101] A chemical passivation layer can passivate surface defects in the first cell absorber layer 200, thereby improving the conversion efficiency of the solar cell. The material of the chemical passivation layer can be, but is not limited to, materials such as PI.

[0102] In one embodiment, referring to Figure 5, step S10 of providing the substrate 100 includes:

[0103] Step S11: Provide a semiconductor substrate 111.

[0104] The semiconductor substrate 111 may be, but is not limited to, a crystalline silicon wafer. The conductivity type of the crystalline silicon wafer may be, but is not limited to, n-type.

[0105] Step S12: Form a second battery structure 110 based on semiconductor substrate 111.

[0106] The crystalline silicon wafer can be cleaned and texturized first.

[0107] Then, a first intrinsic amorphous silicon layer 112 and a second intrinsic amorphous silicon layer 113 can be formed on the two surfaces of the cleaned and texturized crystalline silicon wafer by means of plasma-enhanced chemical vapor deposition or similar processes.

[0108] Then, a p-type doped layer 114 and an n-type doped layer 115 are deposited on the first intrinsic amorphous silicon layer 112 and the second intrinsic amorphous silicon layer 113, respectively. The doped layer can be an amorphous silicon-based material, a microcrystalline silicon-based material, or a nano-silicon-based material.

[0109] The p-type doped layer 114, the first intrinsic amorphous silicon layer 112, the crystalline silicon wafer, the second intrinsic amorphous silicon layer 113, and the n-type doped layer 115 can form the second battery structure 110.

[0110] Step S14: An intermediate layer 120 is formed on the front side of the second battery structure 110.

[0111] An intermediate layer 120 may be formed on the n-type doped layer 115. The intermediate layer 120 may include a tunnel junction and / or a composite layer.

[0112] As an example, a silicon-based thin film can be prepared on an n-type doped layer 115 using a plasma chemical vapor deposition (PECVD) process to serve as a tunnel junction.

[0113] As an example, a back transparent conductive film can be fabricated on an n-type doped layer 115 using magnetron sputtering to serve as a composite layer. The material of the transparent conductive film can include indium tin oxide (ITO), etc.

[0114] After step S14, it may also include:

[0115] Step S15: At least one hole transport layer 140 is formed on the intermediate layer 120.

[0116] In the next step S20, a second solution can be coated onto the hole transport layer 140.

[0117] The hole transport layer 140, the first battery absorption layer 200, and the electron transport layer 300 can form a first battery structure.

[0118] In this embodiment, the second battery structure 110 and the first battery structure can form a stacked battery, thereby improving the efficiency of the solar cell.

[0119] In one embodiment, after step S12 forms the second battery structure 110 based on the semiconductor substrate 111, the method further includes:

[0120] In step S13, a first transparent conductive layer 130 is formed on the back side of the second battery structure 110. The first transparent conductive layer 130 and the intermediate layer 120 are located on opposite sides of the second battery structure 110.

[0121] Specifically, a first transparent conductive layer 130 can be formed on the p-type doped layer 114.

[0122] As an example, the first transparent conductive layer 130 can be formed in step S13, followed by the formation of the intermediate layer 120 in step S14. Of course, the order of preparation of the first transparent conductive layer 130 and the intermediate layer 120 is not limited to this, and can be set according to actual needs.

[0123] After step S70, which involves curing and sintering to form the first battery absorber layer 200 and the electron transport layer 300, the process further includes:

[0124] Step S81: A second transparent conductive layer 400 is formed on the electron transport layer 300.

[0125] The second transparent conductive layer 400 can be formed by reactive plasma deposition or other methods, which will not be further explained here.

[0126] When the electron transport layer 300 is a tin oxide layer, the bonding force between the electron transport layer 300 and the second transparent conductive layer 400 can be improved.

[0127] Step S82: A first electrode 500 is formed on the second transparent conductive layer 400.

[0128] The first silver grid line can be prepared by screen printing to serve as the first electrode 500.

[0129] Step S83: A second electrode 600 is formed on the first transparent conductive layer 130.

[0130] The second silver grid line can be prepared by screen printing to serve as the second electrode 600.

[0131] In one embodiment, a method for preparing a solar cell is provided, comprising:

[0132] Step S11: Provide a semiconductor substrate 111.

[0133] The semiconductor substrate 111 can be an n-type silicon wafer.

[0134] Step S12: Form a second battery structure 110 based on semiconductor substrate 111.

[0135] The n-type silicon wafer can be cleaned and texturized first.

[0136] Then, a first intrinsic amorphous silicon layer 112 and a second intrinsic amorphous silicon layer 113 can be formed on the two surfaces of the cleaned and texturized n-type silicon wafer using processes such as plasma-enhanced chemical vapor deposition. The thickness of the first intrinsic amorphous silicon layer 112 can be approximately 15 nm, and the thickness of the second intrinsic amorphous silicon layer 113 can be approximately 10 nm.

[0137] Then, a p-type doped layer 114 can be deposited on the first intrinsic amorphous silicon layer 112, and an n-type doped layer 115 can be deposited on the second intrinsic amorphous silicon layer 113. The thickness of the p-type doped layer 114 can be approximately 10 nm, and the thickness of the n-type doped layer 115 can be approximately 15 nm.

[0138] The p-type doped layer 114, the first intrinsic amorphous silicon layer 112, the crystalline silicon wafer (semiconductor substrate 111), the second intrinsic amorphous silicon layer 113, and the n-type doped layer 115 can form the second battery structure 110.

[0139] Step S13: A first transparent conductive layer 130 is formed on the back side of the second battery structure 110.

[0140] The first transparent conductive layer 130 can be fabricated on the p-type doped layer 114 by magnetron sputtering. The material of the first transparent conductive layer 130 can be indium tin oxide (ITO), and the thickness can be about 60 nm. The first transparent conductive layer 130 can also be formed by other methods, which will not be further described here.

[0141] In step S14, an intermediate layer 120 is formed on the front side of the second battery structure 110, and the first transparent conductive layer 130 and the intermediate layer 120 are located on opposite sides of the second battery structure 110.

[0142] A silicon-based thin film can be fabricated on an n-type doped layer 115 via plasma-enhanced chemical vapor deposition (PECVD) to serve as a tunnel junction for a tandem solar cell. The thickness of the tunnel junction can be approximately 20 nm.

[0143] Step S15: At least one hole transport layer 140 is formed on the intermediate layer 120.

[0144] A hole transport layer 140 can be fabricated on a silicon-based thin-film tunnel junction using a magnetron sputtering process. The thickness of the hole transport layer 140 can be approximately 10 nm. The material of the hole transport layer 140 can include NiOx, etc.

[0145] Step S21: Coat the second solution onto the substrate 100.

[0146] A perovskite solution (second solution) can be coated on the hole transport layer 140 by a slot coating method.

[0147] Step S22: Extract the solvent from the second solution to form the initial absorption layer.

[0148] Most of the solvent in the perovskite solution can be extracted by methods such as anti-solvent extraction, air knife drying, or vacuum drying to form the initial absorption layer.

[0149] Step S50: Coat the initial absorption layer with the first solution.

[0150] The electron transport layer 300 can be made of tin oxide (SnO2). The solute in the first solution can include tin oxide nanoparticles, with a solute content of approximately 3%. The size of the tin oxide nanoparticles can be approximately 1 μm. The solvent in the first solution can include ethanol, isopropanol, butanediol, etc.

[0151] The first solution can be coated onto the initial absorption layer using a slot coating method.

[0152] In step S70, the substrate 100 coated with the first solution is cured and sintered so that the initial absorption layer forms the first battery absorption layer 200 and the first solution forms the electron transport layer 300.

[0153] The material can be sintered at 150°C for 20 minutes. After sintering, a dry first cell absorber layer 200 and an electron transport layer 300 are obtained. The first cell absorber layer 200 is a perovskite layer, and the electron transport layer 300 is a tin oxide layer. The thickness of the dried tin oxide layer can be approximately 30 nm.

[0154] Step S81: A second transparent conductive layer 400 is formed on the electron transport layer 300.

[0155] A second transparent conductive layer 400 can be formed on the electron transport layer 300 using a process such as reactive plasma deposition (RPD). The material of the second transparent conductive layer 400 can be indium tin oxide (ITO). The film thickness of the second transparent conductive layer 400 can be approximately 80 nm.

[0156] Step S82: A first electrode 500 is formed on the second transparent conductive layer 400.

[0157] The first silver grid lines can be prepared by screen printing to serve as the first electrode 500. The height of the silver grid lines can be approximately 20 micrometers, and the width can be approximately 50 micrometers. The distance between the first silver grid lines can be approximately 2 millimeters.

[0158] Step S83: A second electrode 600 is formed on the first transparent conductive layer 130.

[0159] The second silver grid lines can be fabricated by screen printing to serve as the second electrode 600. The height of the second silver grid lines can be approximately 20 micrometers, and the width can be approximately 50 micrometers. The distance between the second silver grid lines can be approximately 1.5 millimeters.

[0160] In one embodiment, a method for preparing a solar cell is provided, comprising:

[0161] Step S11: Provide a semiconductor substrate 111.

[0162] The semiconductor substrate 111 can be an n-type silicon wafer.

[0163] Step S12: Form a second battery structure 110 based on semiconductor substrate 111.

[0164] The n-type silicon wafer can be cleaned and texturized first.

[0165] Then, a first intrinsic amorphous silicon layer 112 and a second intrinsic amorphous silicon layer 113 can be formed on the two surfaces of the cleaned and texturized n-type silicon wafer using processes such as plasma-enhanced chemical vapor deposition. The thickness of the first intrinsic amorphous silicon layer 112 and the thickness of the second intrinsic amorphous silicon layer 113 can both be approximately 10 nm.

[0166] Then, a p-type doped layer 114 can be deposited on the first intrinsic amorphous silicon layer 112, and an n-type doped layer 115 can be deposited on the second intrinsic amorphous silicon layer 113. The thickness of the p-type doped layer 114 can be approximately 20 nm. The boron doping concentration in the p-type doped layer 114 can be approximately 0.5%. The thickness of the n-type doped layer 115 can be approximately 15 nm. The phosphorus doping concentration in the n-type doped layer 115 can be approximately 0.4%.

[0167] The p-type doped layer 114, the first intrinsic amorphous silicon layer 112, the crystalline silicon wafer, the second intrinsic amorphous silicon layer 113, and the n-type doped layer 115 can form the second battery structure 110.

[0168] Step S13: A first transparent conductive layer 130 is formed on the back side of the second battery structure 110.

[0169] A first transparent conductive layer 130 can be fabricated on the p-type doped layer 114 by magnetron sputtering. The material of the first transparent conductive layer 130 can be aluminum-doped zinc oxide (AZO), and the thickness can be approximately 200 nm.

[0170] In step S14, an intermediate layer 120 is formed on the front side of the second battery structure 110, and the first transparent conductive layer 130 and the intermediate layer 120 are located on opposite sides of the second battery structure 110.

[0171] A back-transparent conductive film can be fabricated on the n-type doped layer 115 by magnetron sputtering as a composite layer for the tandem solar cell. The composite layer can be made of indium tin oxide (ITO) and have a thickness of approximately 10 nm.

[0172] Step S15: At least one hole transport layer 140 is formed on the intermediate layer 120.

[0173] The hole transport layer 140 can be fabricated on the composite layer using techniques such as slot coating. The material of the hole transport layer 140 can be ME-4PACz, and its thickness can be approximately 2 nm.

[0174] Step S21: Coat the second solution onto the substrate 100.

[0175] A perovskite solution (second solution) can be coated on the hole transport layer 140 by a slot coating method.

[0176] Step S22: Extract the solvent from the second solution to form the initial absorption layer.

[0177] Most of the solvent in the perovskite solution can be extracted by methods such as anti-solvent extraction, air knife drying, or vacuum drying to form the initial absorption layer.

[0178] Step S50: Coat the initial absorption layer with the first solution.

[0179] The electron transport layer 300 can be made of tin oxide (SnO2). The solute in the first solution can include tin oxide nanoparticles, with a solute content of approximately 2%. The size of the tin oxide nanoparticles can be approximately 500 nm. Furthermore, the solvent of the first solution can be doped with 0.001% KCl as a first additive. The solvent in the first solution can include ethanol, isopropanol, butanediol, etc.

[0180] The first solution can be coated onto the initial absorption layer using a slot coating method.

[0181] In step S70, the substrate 100 coated with the first solution is cured and sintered so that the initial absorption layer forms the first battery absorption layer 200 and the first solution forms the electron transport layer 300.

[0182] The material can be sintered at 120°C for 20 minutes. After sintering, a dry first cell absorber layer 200 and an electron transport layer 300 are obtained. The first cell absorber layer 200 is a perovskite layer, and the electron transport layer 300 is a tin oxide layer. The thickness of the dried tin oxide layer can be approximately 10 nm.

[0183] Step S81: A second transparent conductive layer 400 is formed on the electron transport layer 300.

[0184] A second transparent conductive layer 400 can be formed on the electron transport layer 300 using a process such as reactive plasma deposition (RPD). The material of the second transparent conductive layer 400 can be indium tungsten oxide (IWO). The film thickness of the second transparent conductive layer 400 can be approximately 80 nm.

[0185] Step S82: A first electrode 500 is formed on the second transparent conductive layer 400.

[0186] The first silver grid lines can be prepared by screen printing to serve as the first electrode 500. The height of the silver grid lines can be approximately 15 micrometers, and the width can be approximately 60 micrometers. The distance between the first silver grid lines can be approximately 2 millimeters.

[0187] Step S83: A second electrode 600 is formed on the first transparent conductive layer 130.

[0188] The second silver grid lines can be fabricated by screen printing to serve as the second electrode 600. The height of the second silver grid lines can be approximately 15 micrometers, and the width can be approximately 50 micrometers. The distance between the second silver grid lines can be approximately 1.5 millimeters.

[0189] In one embodiment, a method for preparing a solar cell is provided, comprising:

[0190] Step S11: Provide a semiconductor substrate 111.

[0191] The semiconductor substrate 111 can be an n-type silicon wafer.

[0192] Step S12: Form a second battery structure 110 based on semiconductor substrate 111.

[0193] The n-type silicon wafer can be cleaned and texturized first.

[0194] Then, a first intrinsic amorphous silicon layer 112 and a second intrinsic amorphous silicon layer 113 can be formed on the two surfaces of the cleaned and texturized n-type silicon wafer using processes such as plasma-enhanced chemical vapor deposition. The thickness of the first intrinsic amorphous silicon layer 112 can be approximately 12 nm, and the thickness of the second intrinsic amorphous silicon layer 113 can be approximately 10 nm.

[0195] Then, a p-type doped layer 114 can be deposited on the first intrinsic amorphous silicon layer 112, and an n-type doped layer 115 can be deposited on the second intrinsic amorphous silicon layer 113. The thickness of the p-type doped layer 114 can be approximately 10 nm, and the thickness of the n-type doped layer 115 can be approximately 15 nm.

[0196] The p-type doped layer 114, the first intrinsic amorphous silicon layer 112, the crystalline silicon wafer, the second intrinsic amorphous silicon layer 113, and the n-type doped layer 115 can form the second battery structure 110.

[0197] Step S13: A first transparent conductive layer 130 is formed on the back side of the second battery structure 110.

[0198] A first transparent conductive layer 130 can be fabricated on the p-type doped layer 114 by magnetron sputtering. The material of the first transparent conductive layer 130 can be indium tin oxide (ITO), and the thickness can be approximately 120 nm.

[0199] In step S14, an intermediate layer 120 is formed on the front side of the second battery structure 110, and the first transparent conductive layer 130 and the intermediate layer 120 are located on opposite sides of the second battery structure 110.

[0200] A silicon-based thin film can be fabricated on an n-type doped layer 115 using plasma-enhanced chemical vapor deposition (PECVD) as a tunnel junction for a tandem solar cell. The thickness of the tunnel junction can be approximately 15 nm.

[0201] Step S15: At least one hole transport layer 140 is formed on the intermediate layer 120.

[0202] A hole transport layer 140 can be fabricated on a silicon-based thin-film tunnel junction using magnetron sputtering. The thickness of the hole transport layer 140 can be approximately 20 nm. The material of the hole transport layer 140 can include NiOx, etc.

[0203] Step S21: Coat the second solution onto the substrate 100.

[0204] A perovskite solution (second solution) can be coated on the hole transport layer 140 by a slot coating method.

[0205] Step S22: Extract the solvent from the second solution to form the initial absorption layer.

[0206] Most of the solvent in the perovskite solution can be extracted by methods such as anti-solvent extraction, air knife drying, or vacuum drying to form the initial absorption layer.

[0207] Step S30: Pre-sinter the initial absorption layer, and the pre-sintering time is shorter than the curing sintering time.

[0208] The initial absorption layer can be sintered at 70℃ for 5 minutes to complete the pre-sintering.

[0209] Step S50: Coat the initial absorption layer with the first solution.

[0210] The electron transport layer 300 can be made of tin oxide (SnO2). The solute in the first solution can include tin oxide nanoparticles, with a solute content of approximately 20%. The size of the tin oxide nanoparticles can be approximately 100 nm. Furthermore, the solvent of the first solution can be doped with 0.001% KCl as a first additive. The solvent in the first solution can include ethanol, isopropanol, butanediol, etc.

[0211] The first solution can be coated onto the pre-sintered initial absorption layer using a slot coating method.

[0212] Step S60: Extract the solvent from the first solution to form an initial electron transport layer.

[0213] Most of the solvent in the first solution can be extracted by methods such as antisolvent extraction, air knife drying, or vacuum drying, thereby forming the initial electron transport layer.

[0214] In step S70, the substrate 100 coated with the first solution is cured and sintered so that the initial absorption layer forms the first battery absorption layer 200 and the first solution forms the electron transport layer 300.

[0215] The initial absorption layer and the initial electron transport layer can be sintered at a sintering temperature of 160℃ for 20 minutes. After sintering, a dry first cell absorption layer 200 and an electron transport layer 300 are obtained. The first cell absorption layer 200 is a perovskite layer, and the electron transport layer 300 is a tin oxide layer. The thickness of the dried tin oxide layer can be approximately 10 nm.

[0216] Step S81: A second transparent conductive layer 400 is formed on the electron transport layer 300.

[0217] A second transparent conductive layer 400 can be formed on the electron transport layer 300 using a process such as reactive plasma deposition (RPD). The material of the second transparent conductive layer 400 can be indium tin oxide (ITO). The film thickness of the second transparent conductive layer 400 can be approximately 80 nm.

[0218] Step S82: A first electrode 500 is formed on the second transparent conductive layer 400.

[0219] The first silver grid lines can be prepared by screen printing to serve as the first electrode 500. The height of the silver grid lines can be approximately 20 micrometers, and the width can be approximately 50 micrometers. The distance between the first silver grid lines can be approximately 2 millimeters.

[0220] Step S83: A second electrode 600 is formed on the first transparent conductive layer 130.

[0221] The second silver grid lines can be fabricated by screen printing to serve as the second electrode 600. The height of the second silver grid lines can be approximately 20 micrometers, and the width can be approximately 50 micrometers. The distance between the second silver grid lines can be approximately 1.5 millimeters.

[0222] It should be understood that although the steps in the flowcharts of Figures 1 to 4 are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in Figures 1 to 4 may include multiple steps or multiple stages, which are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0223] In one embodiment, a solar cell is also provided, which is prepared according to the solar cell preparation method of any of the above embodiments.

[0224] In the description of this specification, references to terms such as "one embodiment," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0225] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0226] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a solar cell, characterized in that, include: Provide a base; An initial absorption layer is formed on the substrate using a solution method; A first solution is coated onto the initial absorption layer; The substrate coated with the first solution is cured and sintered so that the initial absorption layer forms the first battery absorption layer and the first solution forms the electron transport layer.

2. The method for preparing a solar cell according to claim 1, characterized in that, The first battery absorber layer includes a perovskite layer, the electron transport layer includes a tin oxide layer, and the solvent in the first solution is an organic solvent.

3. The method for preparing a solar cell according to claim 1, characterized in that, Before coating the initial absorbent layer with the first solution, the method further includes: The initial absorption layer is pre-sintered, and the pre-sintering time is shorter than the curing sintering time.

4. The method for preparing a solar cell according to claim 1, characterized in that, The method of forming an initial absorption layer on the substrate using a solution method includes: A second solution is coated onto the substrate; The solvent is extracted from the second solution to form an initial absorption layer.

5. The method for preparing a solar cell according to claim 1, characterized in that, Before sintering the substrate coated with the first solution, the method further includes: The solvent is extracted from the first solution to form an initial electron transport layer.

6. The method for preparing a solar cell according to claim 1, characterized in that, The first solution includes a first additive and / or a second additive, wherein the first additive is used to promote the crystallization of the first battery absorber layer and the second additive is used to chemically passivate the first battery absorber layer.

7. The method for preparing a solar cell according to claim 1, characterized in that, Before coating the initial absorbent layer with the first solution, the method further includes: A passivation layer is formed on the initial absorption layer.

8. The method for preparing a solar cell according to claim 1, characterized in that, The substrate provided includes: Provide semiconductor substrates; A second battery structure is formed based on the semiconductor substrate; An intermediate layer is formed on the front side of the second battery structure; At least one hole transport layer is formed on the intermediate layer.

9. The method for preparing a solar cell according to claim 8, characterized in that, After forming the second battery structure based on the semiconductor substrate, the method further includes: A first transparent conductive layer is formed on the back side of the second battery structure, and the first transparent conductive layer and the intermediate layer are respectively located on opposite sides of the second battery structure. The substrate coated with the first solution is then cured and sintered to form a first battery absorption layer from the initial absorption layer. After the first solution forms an electron transport layer, the process further includes: A second transparent conductive layer is formed on the electron transport layer; A first electrode is formed on the second transparent conductive layer; A second electrode is formed on the first transparent conductive layer.

10. The method for preparing a solar cell according to claim 9, characterized in that, The first transparent conductive layer and the second transparent conductive layer are formed in different ways.

11. The method for preparing a solar cell according to claim 6, characterized in that, The first additive includes at least one of MACl, KCl, RbCl, potassium acetate, methylamine acetate, and rubidium acetate, and the second additive includes chloride, iodide, and bromide.

12. A solar cell, characterized in that, Prepared according to any one of claims 1-11.

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