Preparation method of solar cell and solar cell

Abstract

The invention relates to a preparation method of a solar cell and the solar cell. The preparation method of the solar cell comprises the steps of providing a substrate; forming an absorption initial layer on the substrate through a solution method; coating a first solution on the initial absorption layer; and curing and sintering the substrate coated with the first solution, so that the absorption initial layer forms a first battery absorption layer, and the first solution forms an electron transport layer. According to the invention, the electron transmission rate between the first cell absorption layer and the electron transmission layer can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuits, and in particular to a method for preparing a solar cell and a solar cell. Background Art

[0002] The perovskite / silicon-based stacked cell structure is a device that directly converts solar energy into electrical energy. The perovskite / silicon-based stacked cell structure has broad application prospects in modern society due to its high photoelectric conversion efficiency, green environmental protection, and wide range of applications. Among them, the perovskite cell includes an absorption layer and an electron transport layer. The absorption layer can absorb sunlight and convert it into electrical energy. The electron transport layer can transfer photogenerated electrons from the absorption layer to the external circuit, while preventing the recombination of electrons and holes. In the prior art, C60 and its derivatives are often used as materials for the electron transport layer, which are expensive; and the utilization rate of raw materials is low (10~30%) in the coating process using vacuum evaporation and other processes, which further increases the production cost. In addition, the C60 material has poor bonding with the ITO layer and is extremely easy to delaminate, resulting in blocked charge transfer.

[0003] Therefore, the process of preparing perovskite cells in perovskite / silicon-based tandem cells still needs to be improved. Summary of the invention

[0004] Based on this, the present application provides a method for preparing a solar cell and a solar cell that can improve the electron transfer rate.

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

[0006] providing a substrate;

[0007] forming an absorption initial layer on the substrate by a solution method;

[0008] coating a first solution on the initial absorption layer;

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

[0010] In one embodiment, the first battery absorption 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.

[0011] In one embodiment, before coating the first solution on the initial absorption layer, the method further comprises:

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

[0013] In one embodiment, the step of forming an initial absorption layer on the substrate by a solution method comprises:

[0014] coating a second solution on the substrate;

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

[0016] In one embodiment, before sintering the substrate coated with the first solution, the method further comprises:

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

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

[0019] In one embodiment, before coating the first solution on the initial absorption layer, the method further comprises:

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

[0021] In one embodiment, providing a substrate comprises:

[0022] providing a semiconductor substrate;

[0023] forming a second battery structure based on the semiconductor substrate;

[0024] forming an intermediate layer 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] forming a first transparent conductive layer on the back side of the second battery structure, wherein the first transparent conductive layer and the intermediate layer are respectively located on two opposite sides of the second battery structure;

[0028] The substrate coated with the first solution is cured and sintered so that the absorption initial layer forms a first battery absorption layer. After the first solution forms an electron transport layer, the method further comprises:

[0029] forming a second transparent conductive layer on the electron transport layer;

[0030] forming a first electrode 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 above-mentioned method for preparing a solar cell first forms an initial absorption layer on a substrate by a solution method, then coats a first solution on the initial absorption layer, and then sinters the substrate coated with the first solution, thereby simultaneously sintering to form a first battery absorption layer and an electron transport layer. Therefore, the present application can make the first battery absorption layer and the electron transport layer have better contact and bonding, thereby effectively improving the electron transfer rate between the two. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 is a flow chart of a method for preparing a solar cell provided in one embodiment;

[0036] Figure 2 is a flow chart of a method for preparing a solar cell provided in another embodiment;

[0037] Figure 3 is a flow chart of a method for preparing a solar cell provided in yet another embodiment;

[0038] Figure 4 is a flow chart of a method for preparing a solar cell provided in yet another embodiment;

[0039] Figure 5 FIG. 1 is a schematic diagram of a cross-sectional structure of a solar cell provided in another embodiment.

[0040] 100-substrate, 110-second battery 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 DESCRIPTION

[0041] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0042] 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 this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this 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 can be directly on other elements or layers, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, doping type or part discussed below can be represented as the second element, component, region, layer or part.

[0044] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0045] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0046] In one embodiment, see Figure 1 as well as Figure 5 , provides a method for preparing a solar cell, comprising the following steps:

[0047] Step S10, providing a substrate 100.

[0048] The base 100 may include a substrate. The substrate may be used to support solar cells.

[0049] In step S20 , an initial absorption layer is formed on the substrate 100 by a solution method.

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

[0051] Step S50, coating the first solution on the initial absorption layer.

[0052] The first solution is a solution for forming the electron transport layer 300 .

[0053] The solute of the first solution may include the material of the electron transport layer 300 itself. Of course, 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 may be specifically set according to actual needs.

[0054] The coating method of the first solution may be, but is not limited to, spraying, inkjet printing, slit coating, roller coating, and the like.

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

[0056] At this time, the first battery absorption layer 200 and the electron transport layer 300 are sintered simultaneously. It can be understood that the first battery absorption layer 200 is the absorption layer 200 of the first battery structure. The solar cell can be a stacked battery including the first battery structure, or a single-layer battery including the first battery structure, which can be specifically configured according to actual needs.

[0057] In this embodiment, an initial absorption layer is first formed on the substrate 100 by a solution method, and then a first solution is coated on the initial absorption layer, and then the substrate 100 coated with the first solution is sintered, thereby simultaneously sintering to form the first battery absorption layer 200 and the electron transport layer 300. Therefore, this embodiment can make the first battery absorption layer 200 and the electron transport layer 300 have better contact and bonding, thereby effectively improving the electron transmission rate between the two.

[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 time, as an example, in step S50, coating the first solution on the initial absorption layer includes:

[0060] A tin oxide nanopowder solution is coated on the initial absorption layer.

[0061] Specifically, tin oxide can be first made into nanopowder and dispersed in an organic solvent such as alcohol, isopropanol, dibutyl alcohol, etc., to form a tin oxide nanopowder solution.

[0062] Then, the tin oxide nanopowder solution can be coated on the surface of the initial absorption layer by spin coating, slit coating, spray coating, inkjet printing, roll coating and other process methods.

[0063] At this time, the tin oxide nanopowder in the first solution can be prepared separately without considering the chemical stability of the perovskite, so that high-quality tin oxide material that meets the requirements of the electron transport layer 300 can be prepared.

[0064] In this embodiment, a tin oxide layer is used as the electron transport layer 300, and the solvent of the first solution adopts an organic solvent that does not react with perovskite, so as not to cause the decomposition of perovskite. At the same time, the cost of tin oxide is relatively low, which can greatly reduce the production cost. The tin oxide layer used as the electron transport layer 300 is prepared by a solution method, and the material utilization rate is high, so that raw materials can be greatly saved. In addition, the transmittance of tin oxide is high, so that more light can enter the perovskite layer (the first battery absorption layer 200), thereby improving the utilization rate of sunlight of the solar cell, and thus improving the power generation efficiency.

[0065] In one embodiment, see Figure 2 , before step S50, further comprising:

[0066] Step S30, pre-sintering the initial absorption layer, wherein 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 absorption initial layer from being completely dried and cured.

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

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

[0070] The sintering temperature during the pre-sintering may be 70° C.-80° C. The sintering temperature during the curing sintering may be 120° C.-180° C., for example, 150° C.

[0071] In this embodiment, the absorption initial layer is preferably pre-sintered to ensure that the absorption initial layer has a good initial morphology. This can prevent excessive material diffusion between the absorption initial layer and the electron transport initial layer before simultaneous sintering, thereby facilitating the formation of the first battery absorption layer 200 and the electron transport layer 300 that are separated and independent of each other.

[0072] Of course, in other embodiments, when a suitable process can be used to ensure that the initial absorption layer formed in step S20 has a sufficient solidified and shaped morphology, step S30 may not be performed, and the specific configuration may be based on actual needs.

[0073] In one embodiment, step S20 includes:

[0074] Step S21 , coating a second solution on the substrate 100 .

[0075] The second solution is a solution for forming the absorption layer 200. The solute of the second solution may include a precursor for forming the absorption layer 200, or may include the absorption layer 200 material itself, which may be specifically set according to actual needs.

[0076] Step S22, extracting the solvent in the second solution to form an initial absorption layer.

[0077] Most of the solvent in the second solution can be extracted by anti-solvent extraction, air knife drying, vacuum drying, etc., so as to form an initial absorption layer.

[0078] When the solute of the second solution includes a precursor for forming the absorption layer 200, during the process of extracting the solvent of the second solution, appropriate conditions can be provided simultaneously to allow the precursor of the absorption layer 200 to react to form the absorption layer 200 material, thereby forming an absorption initial 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 time, in step S22, during the process of removing the solvent in the precursor solution of the perovskite layer, appropriate conditions may be provided to promote the reaction of the precursor solution of the perovskite layer to form a perovskite material, thereby forming an absorption initial layer.

[0081] In one embodiment, see Figure 3 , before step S70, further comprising:

[0082] Step S60, extracting the solvent in the first solution to form an electron transport initial layer.

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

[0084] Most of the solvent in the first solution can be extracted by anti-solvent extraction, air knife drying, vacuum drying, etc., so as to form an initial electron transport layer.

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

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

[0087] Of course, in other embodiments, the solvent in the first solution may also be a relatively volatile solvent. At this time, after step S50, step S70 may also be directly performed, 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 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 time, a first additive that is beneficial to the crystallization of the perovskite layer can be added to the tin oxide nanopowder solution. The first additive can include but is not limited to any one or more of MACl, KCl, KCl, RbCl, potassium acetate, methylamine acetate and rubidium acetate.

[0092] The first additive can promote crystallization of the first battery absorption layer 200, thereby improving the crystal quality of the first battery absorption layer 200. Moreover, during the curing and sintering in step S70, the first additive can be better diffused into the initial absorption layer, thereby further improving the crystal quality of the first battery absorption layer 200.

[0093] The second additive is used to chemically passivate the first battery absorber layer 200, thereby reducing defects in the first battery absorber layer 200. Specifically, the second additive includes chloride, iodide, bromide, and the like.

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

[0095] In one embodiment, see Figure 4 Before step S50, the following steps may also be included:

[0096] Step S40, forming a passivation layer on the absorption initial layer.

[0097] At this time, in step S50, the first solution may be coated on the surface of the passivation layer.

[0098] The passivation layer may have a relatively small thickness, such as a thickness not greater than 1 nm, so as not to affect electron transport between the first battery absorber layer 200 and the electron transport layer 300 .

[0099] The passivation layer may include a field passivation layer, a chemical passivation layer, or a double passivation layer formed by stacking a field passivation layer and a chemical passivation layer.

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

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

[0102] In one embodiment, see Figure 5 , step S10 provides a substrate 100 including:

[0103] Step S11, providing a semiconductor substrate 111.

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

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

[0106] The crystalline silicon wafer may be cleaned and textured first.

[0107] Then, a first intrinsic amorphous silicon layer 112 and a second intrinsic amorphous silicon layer 113 may be formed on two surfaces of the cleaned and textured crystalline silicon wafer respectively by plasma enhanced chemical vapor deposition process or the like.

[0108] Then, a p-type doping layer 114 and an n-type doping layer 115 are deposited on the first intrinsic amorphous silicon layer 112 and the second intrinsic amorphous silicon layer 113 , respectively. The doping layers may be made of amorphous silicon-based materials, microcrystalline silicon-based materials, or nano-silicon-based materials.

[0109] The p-type doping layer 114 , the first intrinsic amorphous silicon layer 112 , the crystalline silicon wafer, the second intrinsic amorphous silicon 113 , and the n-type doping layer 115 may form a second cell structure 110 .

[0110] In step S14 , an intermediate layer 120 is formed on the front surface of the second battery structure 110 .

[0111] The intermediate layer 120 may be formed on the n-type doping 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 may be formed on the n-type doped layer 115 by a plasma chemical vapor deposition (PECVD) process to serve as a tunnel junction.

[0113] As an example, a back transparent conductive film layer may be prepared on the n-type doped layer 115 by magnetron sputtering process as a composite layer. The material of the transparent conductive film layer may include tin-doped indium oxide (ITO) and the like.

[0114] After step S14, the following steps may also be included:

[0115] Step S15 , forming at least one hole transport layer 140 on the intermediate layer 120 .

[0116] Then, in step S20 , a second solution may be coated on the hole transport layer 140 .

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

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

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

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

[0121] Specifically, the first transparent conductive layer 130 may be formed on the p-type doping layer 114 .

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

[0123] After the step S70 is performed by curing and sintering to form the first battery absorption layer 200 and the electron transport layer 300, the step further includes:

[0124] Step S81 , forming a second transparent conductive layer 400 on the electron transport layer 300 .

[0125] The second transparent conductive layer 400 may be formed by a reactive plasma deposition process or the like, and the second transparent conductive layer 130 may also be formed by other methods, which will not be further described herein.

[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 further improved.

[0127] Step S82 , forming a first electrode 500 on the second transparent conductive layer 400 .

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

[0129] In step S83 , a second electrode 600 is formed on the first transparent conductive layer 130 .

[0130] The second silver grid line may 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, providing a semiconductor substrate 111.

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

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

[0135] The n-type silicon wafer may be cleaned and textured 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 textured n-type silicon wafer by plasma enhanced chemical vapor deposition process, etc. The thickness of the first intrinsic amorphous silicon layer 112 can be about 15nm, and the thickness of the second intrinsic amorphous silicon layer 113 can be about 10nm.

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

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

[0139] In step S13 , a first transparent conductive layer 130 is formed on the back surface of the second battery structure 110 .

[0140] The first transparent conductive layer 130 can be formed by magnetron sputtering on the p-type doped layer 114. The material of the first transparent conductive layer 130 can be indium tin oxide (ITO) with a thickness of 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 surface of the second battery structure 110 . The first transparent conductive layer 130 and the intermediate layer 120 are respectively located on two opposite sides of the second battery structure 110 .

[0142] A silicon-based thin film may be prepared on the n-type doped layer 115 by plasma chemical vapor deposition (PECVD) as a tunnel junction of the stacked cell. The thickness of the tunnel junction may be about 20 nm.

[0143] Step S15 , forming at least one hole transport layer 140 on the intermediate layer 120 .

[0144] The hole transport layer 140 can be prepared on the silicon-based thin film tunnel junction by magnetron sputtering process. The thickness of the hole transport layer 140 can be about 10 nm. The material of the hole transport layer 140 can include NiOx and the like.

[0145] Step S21 , coating a second solution on the substrate 100 .

[0146] The perovskite solution (second solution) may be coated on the hole transport layer 140 by slit coating.

[0147] Step S22, extracting the solvent in the second solution to form an initial absorption layer.

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

[0149] Step S50, coating the first solution on the initial absorption layer.

[0150] The material of the electron transport layer 300 may be tin oxide SnO2. The solute in the first solution may include tin oxide nanoparticles, and the solute content may be about 3%. The size of the tin oxide nanoparticles may be about 1 μm. The solvent in the first solution may include ethanol, isopropanol, butanediol, etc.

[0151] The first solution may be coated on the absorptive initiation layer by slot coating.

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

[0153] The curing sintering can be performed at a sintering temperature of 150° C. for 20 minutes. After sintering, a dried first battery absorption layer 200 and an electron transport layer 300 can be obtained. The first battery absorption layer 200 is a perovskite layer, and the electron transport layer 300 is a tin oxide layer. The film thickness of the dried tin oxide layer can be about 30 nm.

[0154] Step S81 , forming a second transparent conductive layer 400 on the electron transport layer 300 .

[0155] The second transparent conductive layer 400 may be formed on the electron transport layer 300 by a reactive plasma deposition (RPD) process or the like. The material of the second transparent conductive layer 400 may be indium tin oxide (ITO). The film thickness of the second transparent conductive layer 400 may be about 80 nm.

[0156] Step S82 , forming a first electrode 500 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 about 20 micrometers, the width can be about 50 micrometers, and the distance between the first silver grid lines can be about 2 millimeters.

[0158] In step S83 , a second electrode 600 is formed on the first transparent conductive layer 130 .

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

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

[0161] Step S11, providing a semiconductor substrate 111.

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

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

[0164] The n-type silicon wafer may be cleaned and textured first.

[0165] Then, a first intrinsic amorphous silicon layer 112 and a second intrinsic amorphous silicon layer 113 can be formed on both surfaces of the cleaned and textured n-type silicon wafer by plasma enhanced chemical vapor deposition process, etc. The thickness of the first intrinsic amorphous silicon layer 112 and the thickness of the second intrinsic amorphous silicon layer 113 can both be about 10 nm.

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

[0167] The p-type doping layer 114 , the first intrinsic amorphous silicon layer 112 , the crystalline silicon wafer, the second intrinsic amorphous silicon 113 , and the n-type doping layer 115 may form a second cell structure 110 .

[0168] In step S13 , a first transparent conductive layer 130 is formed on the back surface of the second battery structure 110 .

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

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

[0171] A back transparent conductive film layer can be prepared by magnetron sputtering on the n-type doped layer 115 as a composite layer of the stacked battery. The composite layer can be made of tin-doped indium oxide (ITO) with a thickness of about 10 nm.

[0172] Step S15 , forming at least one hole transport layer 140 on the intermediate layer 120 .

[0173] The hole transport layer 140 may be prepared on the composite layer by a slit coating process, etc. The material of the hole transport layer 140 may be ME-4PACz, and the thickness may be about 2 nm.

[0174] Step S21 , coating a second solution on the substrate 100 .

[0175] The perovskite solution (second solution) may be coated on the hole transport layer 140 by slit coating.

[0176] Step S22, extracting the solvent in the second solution to form an initial absorption layer.

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

[0178] Step S50, coating the first solution on the initial absorption layer.

[0179] The material of the electron transport layer 300 may be tin oxide SnO2. The solute in the first solution may include tin oxide nanoparticles, and the solute content may be about 2%. The size of the tin oxide nanoparticles may be about 500nm. In addition, 0.001% KCl may be doped in the solvent of the first solution as a first additive. The solvent in the first solution may include ethanol, isopropanol, butanediol, etc.

[0180] The first solution may be coated on the absorptive initiation layer by slot coating.

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

[0182] The curing sintering can be performed at a sintering temperature of 120° C. for 20 minutes. After sintering, a dried first battery absorption layer 200 and an electron transport layer 300 can be obtained. The first battery absorption layer 200 is a perovskite layer, and the electron transport layer 300 is a tin oxide layer. The film thickness of the dried tin oxide layer can be about 10 nm.

[0183] Step S81 , forming a second transparent conductive layer 400 on the electron transport layer 300 .

[0184] The second transparent conductive layer 400 may be formed on the electron transport layer 300 by a reactive plasma deposition (RPD) process or the like. The material of the second transparent conductive layer 400 may be indium tungsten oxide IWO. The film thickness of the second transparent conductive layer 400 may be about 80 nm.

[0185] Step S82 , forming a first electrode 500 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 about 15 micrometers, the width can be about 60 micrometers, and the distance between the first silver grid lines can be about 2 millimeters.

[0187] In step S83 , a second electrode 600 is formed on the first transparent conductive layer 130 .

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

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

[0190] Step S11, providing a semiconductor substrate 111.

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

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

[0193] The n-type silicon wafer may be cleaned and textured 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 textured n-type silicon wafer by plasma enhanced chemical vapor deposition process, etc. The thickness of the first intrinsic amorphous silicon layer 112 can be about 12nm, and the thickness of the second intrinsic amorphous silicon layer 113 can be about 10nm.

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

[0196] The p-type doping layer 114 , the first intrinsic amorphous silicon layer 112 , the crystalline silicon wafer, the second intrinsic amorphous silicon 113 , and the n-type doping layer 115 may form a second cell structure 110 .

[0197] In step S13 , a first transparent conductive layer 130 is formed on the back surface of the second battery structure 110 .

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

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

[0200] A silicon-based thin film may be prepared on the n-type doped layer 115 by plasma chemical vapor deposition (PECVD) as a tunnel junction of the stacked cell. The thickness of the tunnel junction may be about 15 nm.

[0201] Step S15 , forming at least one hole transport layer 140 on the intermediate layer 120 .

[0202] The hole transport layer 140 can be prepared on the silicon-based thin film tunnel junction by magnetron sputtering process. The thickness of the hole transport layer 140 can be about 20nm. The material of the hole transport layer 140 can include NiOx and the like.

[0203] Step S21 , coating a second solution on the substrate 100 .

[0204] The perovskite solution (second solution) may be coated on the hole transport layer 140 by slit coating.

[0205] Step S22, extracting the solvent in the second solution to form an initial absorption layer.

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

[0207] Step S30, pre-sintering the initial absorption layer, wherein the pre-sintering time is shorter than the curing sintering time.

[0208] The absorbent initial layer may be sintered at 70° C. for 5 minutes to complete the pre-sintering.

[0209] Step S50, coating the first solution on the initial absorption layer.

[0210] The material of the electron transport layer 300 may be tin oxide SnO2. The solute of the first solution may include tin oxide nanoparticles, and the solute content may be about 20%. The size of the tin oxide nanoparticles may be about 100 nm. In addition, 0.001% KCl may be doped in the solvent of the first solution as a first additive. The solvent in the first solution may include ethanol, isopropanol, butanediol, etc.

[0211] The first solution may be coated on the pre-sintered absorption initial layer by slot coating.

[0212] Step S60, extracting the solvent in the first solution to form an electron transport initial layer.

[0213] Most of the solvent in the first solution can be extracted by anti-solvent extraction, air knife drying, vacuum drying, etc., so as to form an initial electron transport layer.

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

[0215] The absorption initial layer and the electron transport initial layer can be sintered at a sintering temperature of 160° C. for 20 minutes. After sintering, a dried first battery absorption layer 200 and an electron transport layer 300 can be obtained. The first battery absorption layer 200 is a perovskite layer, and the electron transport layer 300 is a tin oxide layer. The film thickness of the dried tin oxide layer can be about 10 nm.

[0216] Step S81 , forming a second transparent conductive layer 400 on the electron transport layer 300 .

[0217] The second transparent conductive layer 400 may be formed on the electron transport layer 300 by a reactive plasma deposition (RPD) process or the like. The material of the second transparent conductive layer 400 may be indium tin oxide (ITO). The film thickness of the second transparent conductive layer 400 may be about 80 nm.

[0218] Step S82 , forming a first electrode 500 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 about 20 micrometers, the width can be about 50 micrometers, and the distance between the first silver grid lines can be about 2 millimeters.

[0220] In step S83 , a second electrode 600 is formed on the first transparent conductive layer 130 .

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

[0222] It should be understood that although Figures 1 to 4 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figures 1 to 4 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0223] In one embodiment, a solar cell is further provided, which is prepared according to the method for preparing a solar cell in any of the above embodiments.

[0224] In the description of this specification, the description with reference to the terms "one embodiment", "other embodiments", etc. 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 application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0225] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned 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 above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing a solar cell, characterized in that: include: providing a substrate; forming an absorption initial layer on the substrate by a solution method; coating a first solution on the initial absorption layer; The substrate coated with the first solution is cured and sintered, so that the absorption initial layer forms a first battery absorption layer, and the first solution forms an electron transport layer.

2. The method for preparing a solar cell according to claim 1, characterized in that: The first battery absorption 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 first solution on the initial absorption layer, the method further comprises: The absorption initial 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 by a solution method comprises: coating a second solution on the substrate; The solvent in the second solution is extracted to form an absorption initial 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 comprises: The solvent in the first solution is extracted to form an electron transport initial 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 crystallization of the first battery absorption layer, and the second additive is used to chemically passivate the first battery absorption layer.

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

8. The method for preparing a solar cell according to claim 1, characterized in that: The providing of a substrate comprises: providing a semiconductor substrate; forming a second battery structure based on the semiconductor substrate; forming an intermediate layer 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: forming a first transparent conductive layer on the back side of the second battery structure, wherein the first transparent conductive layer and the intermediate layer are respectively located on two opposite sides of the second battery structure; The substrate coated with the first solution is cured and sintered so that the absorption initial layer forms a first battery absorption layer. After the first solution forms an electron transport layer, the method further comprises: forming a second transparent conductive layer on the electron transport layer; forming a first electrode 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, 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 to 11.

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