All-inorganic perovskite-silicon heterojunction laminated solar cell and preparation method thereof

Abstract

The invention relates to the technical field of solar cells, and discloses an all-inorganic perovskite-silicon heterojunction laminated solar cell and a preparation method thereof.The preparation method comprises the steps that a silicon-bottom cell is provided, the silicon-bottom cell comprises a silicon wafer, a first intrinsic passivation layer on one side of the silicon wafer, an n-type doping layer and a tunneling conducting layer, the second intrinsic passivation layer, the p-type doping layer and the first transparent electrode are arranged on the other side of the silicon wafer; at least the surface, on one side of the tunneling conductive layer, of the silicon-bottom cell is a suede; forming a hole transport layer on the surface of one side, opposite to the n-type doped layer, of the tunneling conductive layer; forming a full-inorganic perovskite layer on the surface of one side, opposite to the tunneling conductive layer, of the hole transport layer by adopting an electrochemical deposition process; and sequentially forming an electron transport layer and a second transparent electrode on the surface of the all-inorganic perovskite layer. According to the invention, the process difficulty of forming the all-inorganic perovskite thin film on the suede can be reduced, the uniformity and the bonding property of the all-inorganic perovskite layer are improved, and the reliability, the stability and the electrical property of the solar cell are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and particularly relates to an all-inorganic perovskite-silicon heterojunction tandem solar cell and a preparation method thereof. Background Art

[0002] Perovskite solar cells have received extensive attention due to their excellent performance and low-cost preparation methods. Their unique crystal structure endows them with excellent charge transport performance and light absorption performance. Therefore, perovskite / silicon heterojunction tandem solar cells can break through the efficiency limit of single-junction cells and are considered to be the next-generation industrialized solar cells.

[0003] In the existing technology for preparing perovskite / silicon solar cells, the preparation of perovskite solar cells mainly adopts a solution processing method, that is, by coating a perovskite precursor solution on a substrate and then forming a perovskite thin film through a heat treatment process. Although this method can achieve the preparation of large-area perovskite thin films, there are certain difficulties in preparing perovskite thin films on a silicon pyramid substrate, mainly because the roughness and curvature of the silicon pyramid surface have an adverse effect on the formation of the perovskite thin film, resulting in poor uniformity and adhesion of the perovskite thin film. Moreover, this preparation method causes serious waste and high preparation costs, which is not conducive to large-scale production. In addition, existing perovskite solar cells generally use organic-inorganic hybrid perovskites, and organic-inorganic hybrid perovskite solar cells have poor stability and are prone to performance degradation due to the influence of the external environment. And the existing preparation methods of perovskite solar cells have high costs, complex preparation processes, and low process efficiency.

[0004] Therefore, how to deposit an all-inorganic perovskite thin film on the textured surface of a large-area silicon heterojunction solar cell, so as to quickly obtain a low-cost large-area perovskite / crystalline silicon tandem solar cell, is an urgent problem to be solved in this field. Summary of the Invention

[0005] In view of this, the present invention provides an all-inorganic perovskite-silicon heterojunction tandem solar cell and a preparation method thereof to solve the problems in the related technology that it is difficult to deposit an all-inorganic perovskite thin film on the textured surface of a large-area silicon heterojunction solar cell, the uniformity and adhesion of the perovskite thin film are poor, the stability of organic-inorganic hybrid perovskite solar cells is low, the preparation cost of perovskite solar cells is high, and the process efficiency is low.

[0006] In a first aspect, the present invention provides a preparation method of an all-inorganic perovskite-silicon heterojunction tandem solar cell, and the preparation method includes:

[0007] A silicon-based battery is provided. The silicon-based battery includes a silicon wafer, a first intrinsic passivation layer, a p-type doping layer, and a first transparent electrode stacked on one side of the silicon wafer, and a second intrinsic passivation layer, an n-type doping layer, and a tunneling conductive layer stacked on the other side of the silicon wafer. At least the surface of the silicon-based battery on one side of the tunneling conductive layer is a matte surface.

[0008] A hole transport layer is formed on the surface of the tunneling conductive layer facing away from the n-type doping layer.

[0009] An all-inorganic perovskite layer is formed on the surface of the hole transport layer facing away from the tunneling conductive layer by using an electrochemical deposition process.

[0010] An electron transport layer and a second transparent electrode are sequentially formed on the surface of the all-inorganic perovskite layer facing away from the hole transport layer.

[0011] The preparation method of the all-inorganic perovskite-silicon heterojunction stacked solar cell provided by the present invention can successfully deposit an all-inorganic perovskite thin film on the matte surface of the silicon heterojunction solar cell by using an electrochemical deposition process. On the one hand, it can reduce the process difficulty of forming the all-inorganic perovskite thin film, improve the uniformity and adhesion of the all-inorganic perovskite layer, and thus improve the reliability of the solar cell. On the other hand, the electrochemical deposition process has the advantages of simple equipment, convenient operation, and low cost. Therefore, it can greatly reduce the preparation cost of the all-inorganic perovskite-silicon heterojunction stacked solar cell, simplify the process flow, and is conducive to large-scale production. In addition, compared with the organic hybrid perovskite, the all-inorganic perovskite thin film can improve the stability of the solar cell, thereby improving the electrical performance of the all-inorganic perovskite-silicon heterojunction stacked solar cell. Therefore, the preparation method of the all-inorganic perovskite-silicon heterojunction stacked solar cell provided by this embodiment can reduce the process difficulty of forming the all-inorganic perovskite thin film on the matte surface, improve the uniformity and adhesion of the all-inorganic perovskite layer, and thus improve the reliability, stability, and electrical performance of the solar cell.

[0012] In an alternative embodiment, the step of forming an all-inorganic perovskite layer on the surface of the hole transport layer facing away from the tunneling conductive layer by using an electrochemical deposition process includes:

[0013] A PbO2 thin film is formed on the surface of the hole transport layer facing away from the tunneling conductive layer by using an electrochemical deposition process.

[0014] A first solution is spin-coated on the surface of the PbO2 thin film to form a perovskite intermediate phase on the PbO2 thin film.

[0015] A second solution is spin-coated on the surface of the perovskite intermediate phase to form an all-inorganic perovskite layer from the all-inorganic perovskite intermediate phase.

[0016] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by the present invention is as follows: First, a PbO2 thin film is formed on the textured surface of the silicon bottom cell by an electrochemical deposition process. Secondly, the PbO2 thin film is transformed into a perovskite intermediate phase by spin-coating a first solution. Finally, the all-inorganic perovskite intermediate phase is transformed into an all-inorganic perovskite layer by spin-coating a second solution; the electrochemical deposition process can improve the uniformity of the PbO2 thin film and the bonding property between the PbO2 thin film and the textured surface, thereby improving the uniformity and bonding property of the all-inorganic perovskite thin film, and thus improving the reliability and stability of the all-inorganic perovskite-silicon heterojunction tandem solar cell.

[0017] In an alternative embodiment, the material of the hole transport layer is NiO x , CuO, MoO3 or V2O5;

[0018] The steps of forming a PbO2 thin film on the surface of the hole transport layer facing away from the tunneling conductive layer by an electrochemical deposition process include:

[0019] Providing an electrolyte, the electrolyte is an aqueous solution containing lead acetate, lead nitrate and nitric acid;

[0020] Placing the silicon bottom cell with the hole transport layer formed thereon in the electrolyte;

[0021] An electrochemical deposition process is carried out using a two-electrode system to form a PbO2 thin film on the surface of the hole transport layer facing away from the tunneling conductive layer.

[0022] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by the present invention places the silicon bottom cell with the hole transport layer formed thereon in an electrolyte containing lead acetate, lead nitrate and nitric acid, and uses a two-electrode system to carry out an electrochemical deposition process to form a PbO2 thin film on the surface of the textured hole transport layer. The equipment of the electrochemical deposition process is simple, the operation is convenient, and the cost is low. A PbO2 thin film with high uniformity and strong bonding property can be formed on the surface of the textured hole transport layer at a low cost, improving the uniformity and bonding property of the subsequent formed all-inorganic perovskite thin film, and thus improving the reliability and stability of the all-inorganic perovskite-silicon heterojunction tandem solar cell. In addition, the formation of the PbO2 thin film can be compatible with low-cost water as the solvent of the electrolyte, and the post-treatment of the lead-containing electrolyte is relatively simple, which can reduce the process cost and simplify the process flow.

[0023] In an alternative embodiment, in the electrolyte, the concentration of lead acetate is 0.05M - 0.2M, the concentration of lead nitrate is 0.1M - 0.4M, and the concentration of nitric acid is 0.05M - 0.2M;

[0024] The deposition current of the electrochemical deposition process is 1mA / cm 2 ~20mA / cm2 The deposition time is 10 s to 250 s.

[0025] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by the present invention can form PbO2 films with different thicknesses, high uniformity, and strong bonding by controlling parameters such as the concentration of the electrolyte, deposition current, and deposition time. Furthermore, the thickness and uniformity of the subsequently formed all-inorganic perovskite film can be controlled, thereby improving the reliability and stability of the all-inorganic perovskite-silicon heterojunction tandem solar cell.

[0026] In an optional embodiment, the first solution is a mixed ethanol solution of one or more of NH4Cl, NH4Br, and NH4I and hydrobromic acid, and at least NH4Br is included. When multiple components are included, the proportion of NH4Br is greater than 50%; the total concentration of one or more of NH4Cl, NH4Br, and NH4I is 0.05 M to 0.3 M;

[0027] The perovskite intermediate phase is NH4Pb2Cl x Br y I 5-x-y ;

[0028] The second solution is an organic solution of one or more of CsCl, CsBr, and CsI; the total concentration of CsCl, CsBr, and CsI is 0.05 M to 0.3 M; the solvent of the second solution is an alcohol organic solvent;

[0029] The material of the all-inorganic perovskite layer is CsPbCl x Br y I 3-x-y .

[0030] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by the present invention forms a perovskite intermediate phase by spin-coating the first solution on the surface of the PbO2 film, and forms an all-inorganic perovskite layer by spin-coating the second solution, enabling the PbO2 film with high uniformity and strong bonding to finally transform into an all-inorganic perovskite layer with high uniformity and strong bonding. At the same time, by controlling the composition and concentration of the first solution and the second solution, all-inorganic perovskite films with different compositions can be obtained, simplifying the process flow and broadening the application scenarios of solar cells.

[0031] In an optional embodiment, the first solution is a mixed ethanol solution of NH4Br and hydrobromic acid;

[0032] The perovskite intermediate phase is NH4Pb2Br5;

[0033] The second solution is a methanol solution of CsBr;

[0034] The material of the all-inorganic perovskite layer is CsPbBr3.

[0035] In an alternative embodiment, the first solution is a mixed ethanol solution of NH4Cl, NH4Br, NH4I and hydrobromic acid; the ratio of NH4Cl:NH4Br:NH4I is 1:3:1;

[0036] The perovskite intermediate phase is NH4Pb2ClBr3I;

[0037] The material of the all-inorganic perovskite layer is CsPbCl 0.6 Br 1.8 I 0.6 .

[0038] In an alternative embodiment, after the step of spin-coating a second solution on the surface of the perovskite intermediate phase to form an all-inorganic perovskite layer, the method further includes:

[0039] Heating the silicon-based solar cell with the formed all-inorganic perovskite layer to a first temperature; cooling to room temperature after a first period of time.

[0040] In an alternative embodiment, the electron transport layer includes a C 60 layer and a SnO2 thin film;

[0041] The steps of sequentially forming an electron transport layer and a second transparent electrode on the surface of the all-inorganic perovskite layer facing away from the hole transport layer include:

[0042] Forming a C 60 layer on the surface of the all-inorganic perovskite layer facing away from the hole transport layer by thermal evaporation;

[0043] Forming a SnO2 thin film on the surface of the C 60 layer facing away from the all-inorganic perovskite layer by atomic layer deposition;

[0044] Forming a second transparent electrode on the surface of the electron transport layer facing away from the all-inorganic perovskite layer by physical vapor deposition;

[0045] After the steps of sequentially forming an electron transport layer and a second transparent electrode on the surface of the all-inorganic perovskite layer facing away from the hole transport layer, the method further includes:

[0046] Forming metal grid lines on the surface of the second transparent electrode facing away from the electron transport layer by screen printing or magnetron sputtering.

[0047] In an alternative embodiment, the step of providing a silicon-based solar cell includes:

[0048] Providing a silicon wafer;

[0049] Perform a texturing process on the silicon wafer so that the silicon wafer has opposite first and second textured surfaces;

[0050] Form a first intrinsic passivation layer, a p-type doping layer, and a first transparent electrode in sequence on the first textured surface of the silicon wafer; form a second intrinsic passivation layer, an n-type doping layer, and a tunneling conductive layer in sequence on the second textured surface of the silicon wafer; the tunneling conductive layer and the first transparent electrode are textured surfaces.

[0051] In an optional implementation manner, the step of providing the silicon bottom cell further includes:

[0052] Form a metal electrode on the surface of the first transparent electrode facing away from the p-type doping layer; the metal electrode serves as a reflective layer.

[0053] In a second aspect, the present invention provides an all-inorganic perovskite-silicon heterojunction tandem solar cell, and the all-inorganic perovskite-silicon heterojunction tandem solar cell includes:

[0054] A silicon bottom cell, which includes a silicon wafer, a first intrinsic passivation layer, a p-type doping layer, and a first transparent electrode stacked on one side of the silicon wafer, and a second intrinsic passivation layer, an n-type doping layer, and a tunneling conductive layer stacked on the other side of the silicon wafer; at least the surface of the silicon bottom cell on one side of the tunneling conductive layer is a textured surface;

[0055] A hole transport layer, located on the surface of the tunneling conductive layer facing away from the n-type doping layer;

[0056] An all-inorganic perovskite layer, located on the surface of the hole transport layer facing away from the tunneling conductive layer; the all-inorganic perovskite layer is suitable for being formed by an electrochemical deposition process;

[0057] An electron transport layer, located on the surface of the all-inorganic perovskite layer facing away from the hole transport layer;

[0058] A second transparent electrode, located on the surface of the electron transport layer facing away from the all-inorganic perovskite layer.

[0059] In the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by the present invention, the all-inorganic perovskite layer is located on the surface of the hole transport layer facing away from the tunneling conductive layer, and the all-inorganic perovskite layer is suitable for being formed by an electrochemical deposition process. On the one hand, it can improve the uniformity and adhesion of the all-inorganic perovskite thin film, thereby improving the reliability of the solar cell and reducing the preparation cost of the solar cell; on the other hand, compared with the organic hybrid perovskite, the all-inorganic perovskite thin film can improve the stability of the solar cell, thereby improving the electrical performance of the all-inorganic perovskite-silicon heterojunction tandem solar cell. Therefore, the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by the present invention can improve the uniformity and adhesion of the all-inorganic perovskite thin film, and thereby improve the reliability, stability, and electrical performance of the solar cell.

[0060] In an alternative embodiment, the material of the first intrinsic passivation layer and the material of the second intrinsic passivation layer are intrinsic hydrogenated amorphous silicon;

[0061] The material of the n-type doping layer is phosphorus-doped hydrogenated microcrystalline silicon or phosphorus-doped hydrogenated microcrystalline silicon;

[0062] The material of the p-type doping layer is boron-doped hydrogenated microcrystalline silicon or boron-doped hydrogenated microcrystalline silicon;

[0063] The material of the first transparent electrode and the material of the second transparent electrode are ITO, IZO, IWO or AZO;

[0064] The material of the tunneling conductive layer is a transparent conductive oxide or a metal;

[0065] The material of the hole transport layer is NiO x , CuO, MoO3 or V2O5;

[0066] The material of the all-inorganic perovskite layer is CsPbCl x Br y I 3-x-y ;

[0067] The electron transport layer includes a stacked C 60 layer and a SnO2 thin film; the C 60 layer is closer to the all-inorganic perovskite layer side;

[0068] The thickness of the first intrinsic passivation layer and the second intrinsic passivation layer is 4nm to 10nm;

[0069] The thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 5nm to 20nm; the thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 20nm to 40nm;

[0070] The thickness of the boron-doped hydrogenated microcrystalline silicon is 5nm to 20nm; the thickness of the boron-doped hydrogenated microcrystalline silicon is 20nm to 60nm;

[0071] The thickness of the first transparent electrode and the second transparent electrode is 60nm to 120nm;

[0072] C 60 The thickness of the layer is 10nm to 50nm, and the thickness of the SnO2 thin film is 10nm to 80nm.

[0073] In an alternative embodiment, the all-inorganic perovskite-silicon heterojunction stacked solar cell further includes:

[0074] A metal electrode, located on the surface of the first transparent electrode facing away from the p-type doping layer;

[0075] A metal grid line, located on the surface of the second transparent electrode facing away from the electron transport layer;

[0076] The material of the metal electrode is silver, copper, aluminum or nickel; the thickness of the metal electrode is 100 nm to 300 nm;

[0077] The material of the metal grid line is silver, copper, aluminum or nickel; the thickness of the metal grid line is 60 nm to 120 nm. Brief Description of the Drawings

[0078] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the related art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0079] Figure 1 It is a schematic flow chart of a preparation method of an all-inorganic perovskite-silicon heterojunction tandem solar cell according to an embodiment of the present invention.

[0080] Figure 2 It is a specific schematic flow chart of a preparation method of an all-inorganic perovskite-silicon heterojunction tandem solar cell according to an embodiment of the present invention.

[0081] Figure 3 It is a schematic structural diagram of texturing of a silicon wafer in a preparation method of an all-inorganic perovskite-silicon heterojunction tandem solar cell according to an embodiment of the present invention.

[0082] Figure 4 It is a schematic structural diagram of a silicon bottom cell in a preparation method of an all-inorganic perovskite-silicon heterojunction tandem solar cell according to an embodiment of the present invention.

[0083] Figure 5 It is a schematic structural diagram of forming an all-inorganic perovskite layer in a preparation method of an all-inorganic perovskite-silicon heterojunction tandem solar cell according to an embodiment of the present invention.

[0084] Figure 6 It is a schematic structural diagram of an all-inorganic perovskite-silicon heterojunction tandem solar cell according to an embodiment of the present invention.

[0085] Reference Signs:

[0086] 100, silicon bottom cell; 10, silicon wafer; 11, first intrinsic passivation layer; 12, p-type doping layer; 13, first transparent electrode; 14, metal electrode; 21, second intrinsic passivation layer; 22, n-type doping layer; 23, tunneling conductive layer; 31, hole transport layer; 32, all-inorganic perovskite layer; 33, electron transport layer; 34, second transparent electrode; 35, metal grid line. Detailed Embodiments

[0087] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0088] In the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concepts of the present invention. Various schematic structural diagrams according to embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, and for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations. And those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there may be an intermediate layer / component between them. Additionally, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component can be "under" the other layer / component.

[0089] Perovskite solar cells have received extensive attention due to their excellent performance and low-cost preparation methods. Their unique crystal structure endows them with excellent charge transport performance and light absorption performance. Therefore, perovskite / silicon heterojunction tandem solar cells can break through the efficiency limit of single-junction cells and are considered the next-generation industrialized solar cells.

[0090] In the existing technology for preparing perovskite / silicon solar cells, the preparation of perovskite solar cells mainly adopts a solution processing method, that is, by coating a perovskite precursor solution on a substrate and then forming a perovskite film through a heat treatment process. Although this method can achieve the preparation of large-area perovskite films, there are certain difficulties in preparing perovskite films on silicon pyramid substrates, mainly because the roughness and curvature of the silicon pyramid surface have an adverse effect on the formation of perovskite films, resulting in poor uniformity and adhesion of the perovskite films. And this preparation method causes serious waste and high preparation costs, which is not conducive to large-scale production. In addition, existing perovskite solar cells generally use organic-inorganic hybrid perovskites, and organic-inorganic hybrid perovskite solar cells have poor stability and are easily affected by the external environment and suffer from performance degradation. And the existing preparation methods of perovskite solar cells have high costs, complex preparation processes, and low process efficiency.

[0091] Therefore, how to deposit a fully inorganic perovskite thin film on the textured surface of a large-area silicon heterojunction solar cell, so as to quickly obtain a large-area perovskite / silicon heterojunction solar cell with lower cost, is an urgent problem to be solved in this field currently.

[0092] Electrochemical deposition can utilize the reduction or oxidation reaction of ions in the electrolyte solution on the electrode surface under the action of an electric field, thereby forming a solid thin film on the electrode surface. This method has the advantages of simple equipment, convenient operation, low cost, etc. Moreover, the thin film formed by the electrochemical deposition process has high uniformity and good adhesion, so it has been widely used in the preparation of thin film materials. Therefore, this solution proposes to use the electrochemical deposition method to prepare a perovskite structure on a silicon heterojunction cell.

[0093] As Figure 1 shown, this embodiment provides a preparation method for a fully inorganic perovskite-silicon heterojunction tandem solar cell, and this preparation method includes but is not limited to steps S101 to S104.

[0094] Step S101, provide a silicon bottom cell 100, the silicon bottom cell 100 includes a silicon wafer 10, a first intrinsic passivation layer 11, a p-type doping layer 12, and a first transparent electrode 13 laminated on one side of the silicon wafer 10, and a second intrinsic passivation layer 21, an n-type doping layer 22, and a tunneling conductive layer 23 laminated on the other side of the silicon wafer 10; at least the surface of the silicon bottom cell on one side of the tunneling conductive layer 23 is a textured surface, as Figure 4 shown.

[0095] Step S102, form a hole transport layer 31 on the surface of the tunneling conductive layer 23 facing away from the n-type doping layer 22.

[0096] Step S103, use the electrochemical deposition process to form a fully inorganic perovskite layer 32 on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23, as Figure 5 shown.

[0097] Step S104, sequentially form an electron transport layer 33 and a second transparent electrode 34 on the surface of the fully inorganic perovskite layer 32 facing away from the hole transport layer 31, as Figure 6 shown.

[0098] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by this embodiment can successfully deposit an all-inorganic perovskite thin film on the textured surface of the silicon heterojunction solar cell by using the electrochemical deposition process. On the one hand, it can reduce the process difficulty of forming the all-inorganic perovskite thin film, improve the uniformity and bonding property of the all-inorganic perovskite layer, and thus improve the reliability of the solar cell; on the other hand, the electrochemical deposition process has the advantages of simple equipment, convenient operation, and low cost. Therefore, it can greatly reduce the preparation cost of the all-inorganic perovskite-silicon heterojunction tandem solar cell, simplify the process flow, and is conducive to large-scale production; in addition, compared with organic hybrid perovskites, the all-inorganic perovskite thin film can improve the stability of the solar cell, thereby improving the electrical performance of the all-inorganic perovskite-silicon heterojunction tandem solar cell. Therefore, the preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by this embodiment can reduce the process difficulty of forming the all-inorganic perovskite thin film on the textured surface, improve the uniformity and bonding property of the all-inorganic perovskite layer, and thus improve the reliability, stability, and electrical performance of the solar cell.

[0099] In some alternative embodiments, the step of forming the all-inorganic perovskite layer 32 on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23 by using the electrochemical deposition process includes:

[0100] Form a PbO2 thin film on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23 by using the electrochemical deposition process;

[0101] Spin-coat the first solution on the surface of the PbO2 thin film to form a perovskite intermediate phase;

[0102] Spin-coat the second solution on the surface of the perovskite intermediate phase to form the all-inorganic perovskite layer 32 from the all-inorganic perovskite intermediate phase.

[0103] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by this embodiment first forms a PbO2 thin film on the textured surface of the silicon bottom cell by using the electrochemical deposition process. Secondly, by spin-coating the first solution, the PbO2 thin film is transformed into a perovskite intermediate phase. Finally, by spin-coating the second solution, the all-inorganic perovskite intermediate phase is transformed into the all-inorganic perovskite layer; the electrochemical deposition process can improve the uniformity of the PbO2 thin film and the bonding property between the PbO2 thin film and the textured surface, thereby improving the uniformity and bonding property of the all-inorganic perovskite thin film, and thus improving the reliability and stability of the all-inorganic perovskite-silicon heterojunction tandem solar cell.

[0104] In some alternative embodiments, the material of the hole transport layer 31 is NiO x , CuO, MoO3 or V2O5;

[0105] The steps of forming a PbO2 film on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23 by using an electrochemical deposition process include:

[0106] Providing an electrolyte solution, which is an aqueous solution containing lead acetate, lead nitrate and nitric acid;

[0107] Placing the silicon bottom cell with the hole transport layer 31 formed therein into the electrolyte solution;

[0108] Adopting a two - electrode system for the electrochemical deposition process to form a PbO2 film on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23.

[0109] Specifically, when implemented, the material of the hole transport layer 31 is NiO x , CuO, MoO3 or V2O5, which can make the hole transport layer 31 stably exist in the electrolyte solution and have good adhesion with the subsequently deposited PbO2. In one example, the material of the hole transport layer 31 is NiO x .

[0110] The preparation method of the all - inorganic perovskite - silicon heterojunction stacked solar cell provided in this embodiment places the silicon bottom cell with the hole transport layer formed therein into an electrolyte solution containing lead acetate, lead nitrate and nitric acid, and adopts a two - electrode system for the electrochemical deposition process to form a PbO2 film on the surface of the textured hole transport layer. The equipment for the electrochemical deposition process is simple, the operation is convenient, and the cost is low. It can form a PbO2 film with high uniformity and strong bonding on the surface of the textured hole transport layer at a relatively low cost, improve the uniformity and bonding of the subsequently formed all - inorganic perovskite film, and thus improve the reliability and stability of the all - inorganic perovskite - silicon heterojunction stacked solar cell. In addition, the formation of the PbO2 film can be compatible with low - cost water as the solvent of the electrolyte solution, and the post - treatment of the lead - containing electrolyte solution is relatively simple, which can reduce the process cost and simplify the process flow.

[0111] In some optional implementation manners, in the electrolyte solution, the concentration of lead acetate is 0.05M - 0.2M, the concentration of lead nitrate is 0.1M - 0.4M, and the concentration of nitric acid is 0.05M - 0.2M;

[0112] The deposition current of the electrochemical deposition process is 1mA / cm 2 ~20mA / cm 2 , and the deposition time is 10s - 250s.

[0113] In some optional implementation manners, the concentration of lead acetate in the electrolyte solution is 0.1M, the concentration of lead nitrate is 0.2M, and the concentration of nitric acid is 0.1M. In one example, the deposition current is 3mA / cm 2, the time is 120 s; in another example, the deposition current is 5 mA / cm 2 , the time is 60 s.

[0114] In some alternative embodiments, the first solution is a mixed ethanol solution of one or more of NH4Cl, NH4Br, NH4I and hydrobromic acid, and at least includes NH4Br. When multiple components are included, the proportion of NH4Br is greater than 50%; the total concentration of one or more of NH4Cl, NH4Br, NH4I is 0.05 M to 0.3 M;

[0115] The perovskite intermediate phase is NH4Pb2Cl x Br y I 5-x-y ;

[0116] The second solution is an organic solution of one or more of CsCl, CsBr, CsI; the total concentration of CsCl, CsBr, CsI is 0.05 M to 0.3 M; the solvent of the second solution is an alcohol-based organic solvent;

[0117] The material of the all-inorganic perovskite layer 32 is CsPbCl x Br y I 3-x-y .

[0118] In some alternative embodiments, the first solution is a mixed ethanol solution of NH4Br and hydrobromic acid;

[0119] The perovskite intermediate phase is NH4Pb2Br5.

[0120] In some alternative embodiments, the second solution is a methanol solution of CsBr;

[0121] The material of the all-inorganic perovskite layer 32 is CsPbBr3.

[0122] In some alternative embodiments, the first solution is a mixed ethanol solution of NH4Cl, NH4Br, NH4I and hydrobromic acid; the ratio of NH4Cl:NH4Br:NH4I is 1:3:1;

[0123] The perovskite intermediate phase is NH4Pb2ClBr3I.

[0124] In some alternative embodiments, the material of the all-inorganic perovskite layer 32 is CsPbCl 0.6 Br 1.8 I 0.6 .

[0125] In some alternative embodiments, after the step of spin-coating the second solution on the surface of the perovskite intermediate phase to form the all-inorganic perovskite layer 32 from the all-inorganic perovskite intermediate phase, it further includes:

[0126] Heat the silicon-based battery that will form the all-inorganic perovskite layer 32 to a first temperature; after a first period of time, cool it to room temperature.

[0127] In specific implementation, the first temperature is 180°C to 220°C, and the first period of time is 5 min to 30 min.

[0128] In Examples 1 to 3, by controlling the compositions and concentrations of the first solution and the second solution, all-inorganic perovskite layers 32 with different compositions can be prepared.

[0129] In Example 1, the first solution is a mixed ethanol solution of NH4Br and hydrobromic acid with a concentration of 0.1 M; the second solution is a methanol solution of CsBr with a concentration of 0.1 M. First, spin-coat the mixed ethanol solution of NH4Br and hydrobromic acid on the PbO2 film. The color of the yellow-brown film quickly changes to white, and the PbO2 film transforms to form the perovskite intermediate phase NH4Pb2Br5. Then, spin-coat the methanol solution of CsBr on the perovskite intermediate phase NH4Pb2Br5 substrate. Heat-treat the dried sample on a heating plate at 200°C for 10 min, and then naturally cool it to room temperature. The material of the finally formed all-inorganic perovskite layer is CsPbBr3.

[0130] In Example 2, the first solution is a mixed ethanol solution of NH4Cl, NH4Br, NH4I, and hydrobromic acid; the ratio of NH4Cl:NH4Br:NH4I is 1:3:1; other conditions are the same as in Example 1. The formed perovskite intermediate phase is NH4Pb2ClBr3I; the material of the finally formed all-inorganic perovskite layer 32 is CsPbCl 0.6 Br 1.8 I 0.6 .

[0131] In Example 3, the second solution is an organic solution of one or more of CsCl, CsBr, and CsI; the total concentration of CsCl, CsBr, and CsI is 0.05 M to 0.3 M; other conditions are the same as in Example 2; the formed perovskite intermediate phase is still NH4Pb2Br5; the material of the finally formed all-inorganic perovskite layer 32 is CsPbCl x Br y I 3-x-y .

[0132] The preparation method of the all-inorganic perovskite-silicon heterojunction tandem solar cell provided by this embodiment is to spin-coat a first solution on the surface of the PbO2 film to convert the PbO2 film into a perovskite intermediate phase, and spin-coat a second solution to convert the all-inorganic perovskite intermediate phase into an all-inorganic perovskite layer; it can finally convert the PbO2 film with high uniformity and strong bonding into an all-inorganic perovskite layer with high uniformity and strong bonding; at the same time, by controlling the composition and concentration of the first solution and the second solution, all-inorganic perovskite films with different compositions can be obtained, simplifying the process flow and broadening the application scenarios of solar cells.

[0133] In some alternative embodiments, the electron transport layer 33 includes a C 60 layer and a SnO2 film;

[0134] The steps of sequentially forming the electron transport layer 33 and the second transparent electrode 34 on one side surface of the all-inorganic perovskite layer 32 facing away from the hole transport layer 31 include:

[0135] Form a C 60 layer on one side surface of the all-inorganic perovskite layer 32 facing away from the hole transport layer 31 by thermal evaporation;

[0136] On the side surface of the C 60 layer facing away from the all-inorganic perovskite layer 32, form a SnO2 film by atomic layer deposition;

[0137] Form the second transparent electrode 34 on the side surface of the electron transport layer 33 facing away from the all-inorganic perovskite layer 32 by physical vapor deposition;

[0138] After the steps of sequentially forming the electron transport layer 33 and the second transparent electrode 34 on one side surface of the all-inorganic perovskite layer 32 facing away from the hole transport layer 31, it further includes:

[0139] Form metal grid lines 35 on the side surface of the second transparent electrode 34 facing away from the electron transport layer 33 by screen printing or magnetron sputtering.

[0140] Specifically, the thickness of the C 60 layer is 10 nm to 50 nm, the thickness of the SnO2 film is 10 nm to 80 nm, and the atomic layer deposition temperature is 80 °C to 200 °C. First, deposit the C 60 layer on the perovskite substrate by thermal evaporation, and then prepare the SnO2 film on the C 60 layer using atomic layer deposition technology. In one example, the thickness of the C 60 film is 25 nm, the thickness of the SnO2 film is 20 nm, and the atomic layer deposition temperature is 100 °C. The temperatures of the TDMASn precursor and the reactant H2O used in atomic layer deposition are 80 °C and 20 °C respectively, and the carrier gas is nitrogen.

[0141] In some alternative embodiments, the steps of providing the silicon-based cell 100 include:

[0142] Providing a silicon wafer 10;

[0143] Performing a texturing process on the silicon wafer 10 such that the silicon wafer 10 has opposite first and second textured surfaces;

[0144] Successively forming a first intrinsic passivation layer 11, a p-type doping layer 12, and a first transparent electrode 13 on the first textured surface of the silicon wafer 10; successively forming a second intrinsic passivation layer 21, an n-type doping layer 22, and a tunneling conductive layer 23 on the second textured surface of the silicon wafer 10; the tunneling conductive layer 23 and the first transparent electrode 13 are textured surfaces.

[0145] In some alternative embodiments, the steps of providing the silicon-based cell 100 further include:

[0146] Forming a metal electrode 14 on the surface of the first transparent electrode 13 on the side facing away from the p-type doping layer 12; the metal electrode 14 serves as a reflective layer.

[0147] In specific implementation, first, the first intrinsic passivation layer 11 and the second intrinsic passivation layer 21 are respectively deposited on the first and second textured surfaces of the silicon wafer 10. Secondly, the p-type doping layer 12 and the n-type doping layer 22 are respectively formed on the surfaces of the first intrinsic passivation layer 11 and the second intrinsic passivation layer 21 by plasma-enhanced chemical vapor deposition. Then, the first transparent electrode 13 and the metal electrode 14 are formed on the surface of the p-type doping layer 12 on one side of the first textured surface by physical vapor deposition; finally, the tunneling conductive layer 23 is formed on the surface of the n-type doping layer 22 on one side of the second textured surface by magnetron sputtering.

[0148] As Figure 2 shown, the present invention also provides a schematic flow chart of a preparation method for an all-inorganic perovskite-silicon heterojunction tandem solar cell, including but not limited to steps S201 to S212.

[0149] Step S201, providing a silicon wafer 10; performing a texturing process on the silicon wafer 10 such that the silicon wafer 10 has opposite first and second textured surfaces, as Figure 3 shown.

[0150] In specific implementation, first, the silicon wafer 10 is pre-cleaned with a mixed solution of ammonia water and hydrogen peroxide, then the surface damage of the silicon wafer 10 is removed using a KOH solution, and finally the silicon wafer 10 is textured using a texturing solution. The texturing solution is a mixed solution of KOH and isopropyl alcohol additive, and the texturing conditions are that the concentration of KOH is 2% to 12%, the texturing time is 300 s to 6000 s, and the temperature is 50 °C to 90 °C.

[0151] Step S202: Deposit a first intrinsic passivation layer 11 and a second intrinsic passivation layer 21 on the first textured surface and the second textured surface of the silicon wafer 10 respectively.

[0152] In specific implementation, the material of the first intrinsic passivation layer 11 and the material of the second intrinsic passivation layer 21 are intrinsic hydrogenated amorphous silicon; the thickness of the first intrinsic passivation layer 11 and the second intrinsic passivation layer 21 is 4nm - 10nm; the deposition temperature of the intrinsic passivation layer is 160°C - 220°C.

[0153] Step S203: Form a p-type doped layer 12 and an n-type doped layer 22 on the surface of the first intrinsic passivation layer 11 facing away from the first textured surface and the surface of the second intrinsic passivation layer 21 facing away from the second textured surface respectively by plasma enhanced chemical vapor deposition.

[0154] In specific implementation, the material of the n-type doped layer 22 is phosphorus-doped hydrogenated microcrystalline silicon or phosphorus-doped hydrogenated microcrystalline silicon; the thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 5nm - 20nm; the thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 20nm - 40nm; the material of the p-type doped layer 12 is boron-doped hydrogenated microcrystalline silicon or boron-doped hydrogenated microcrystalline silicon; the thickness of the boron-doped hydrogenated microcrystalline silicon is 5nm - 20nm; the thickness of the boron-doped hydrogenated microcrystalline silicon is 20nm - 60nm. The deposition temperature of the n-type doped layer 22 is 180°C - 200°C; the deposition temperature of the p-type doped layer 12 is 150°C - 200°C.

[0155] Step S204: Form a first transparent electrode 13 on the surface of the p-type doped layer 12 facing away from the first intrinsic passivation layer 11 by physical vapor deposition process, and form a metal electrode 14 on the surface of the first transparent electrode 13 by magnetron sputtering process.

[0156] In specific implementation, the material of the first transparent electrode 13 is a transparent oxide such as ITO (indium tin oxide), IZO (indium zinc oxide), IWO (indium tungsten oxide) or AZO (aluminum zinc oxide), and the thickness of the first transparent electrode 13 is 60nm - 120nm; the material of the metal electrode 14 is silver, copper, aluminum or nickel; the thickness of the metal electrode 14 is 100nm - 300nm.

[0157] Step S205: Form a tunneling conductive layer 23 on the surface of the n-type doped layer 22 facing away from the second intrinsic passivation layer 21 by magnetron sputtering process to form a silicon bottom cell 100, as Figure 4 shown.

[0158] In specific implementation, the material of the tunneling conductive layer 23 is a transparent conductive oxide or a metal; when the material of the tunneling conductive layer 23 is a transparent oxide such as ITO, IZO, IWO or AZO, the thickness is 5nm - 20nm, and when the material of the tunneling conductive layer 23 is a metal such as gold, silver or platinum, the thickness is 1nm - 4nm.

[0159] Step S206: Form a hole transport layer 31 on the surface of the tunneling conductive layer 23 facing away from the n-type doped layer 22.

[0160] Specifically, the material of the hole transport layer 31 is NiO x . The process for forming the hole transport layer 31 is as follows: First, the silicon-based battery is treated with ultraviolet ozone for 5 min to 20 min, and then an aqueous solution of NiO x nanoparticles with a concentration of 20 mg / mL is spin-coated on the tunneling conductive layer 23 at a rotation speed of 2000 rpm to 5000 rpm for 10 s to 60 s. And it is annealed in an air environment on a hot plate at a temperature of 80 °C to 120 °C for 5 min to 20 min. After that, an alcohol solution of Me-4PACZ with a concentration of 1 mg / mL is spin-coated on the NiO x substrate to regulate the work function of NiO x , with a rotation speed of 2000 rpm to 6000 rpm for 10 s to 40 s. And it is annealed in a nitrogen environment at an annealing temperature of 80 °C to 120 °C for 3 min to 10 min.

[0161] Step S207: Provide an electrolyte, which is an aqueous solution containing lead acetate, lead nitrate, and nitric acid.

[0162] Specifically, in the electrolyte, the concentration of lead acetate is 0.05 M to 0.2 M, the concentration of lead nitrate is 0.1 M to 0.4 M, and the concentration of nitric acid is 0.05 M to 0.2 M.

[0163] Step S208: Place the silicon-based battery with the formed hole transport layer 31 in the electrolyte; adopt a two-electrode system for the electrochemical deposition process to form a PbO2 thin film on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23.

[0164] Specifically, the deposition current of the electrochemical deposition process is 1 mA / cm 2 to 20 mA / cm 2 , and the deposition time is 10 s to 250 s.

[0165] Step S209: Spin-coat a first solution on the surface of the PbO2 thin film to form a perovskite intermediate phase; wherein, the first solution is a mixed ethanol solution of one or more of NH4Cl, NH4Br, NH4I and hydrobromic acid; the total concentration of one or more of NH4Cl, NH4Br, NH4I is 0.05 M to 0.3 M; the proportion of NH4Br is greater than 50%; the perovskite intermediate phase is NH4Pb2Cl x Br y I 5-x-y .

[0166] Step S210, spin-coat a second solution on the surface of the perovskite intermediate phase to form an all-inorganic perovskite layer 32; wherein, the second solution is an organic solution of one or more of CsCl, CsBr, and CsI; the total concentration of CsCl, CsBr, and CsI is 0.05 M to 0.3 M; the solvent of the second solution is an alcohol-based organic solvent.

[0167] Step S211, heat the silicon-based cell with the formed all-inorganic perovskite layer 32 to a first temperature; after maintaining for a first period of time, cool it to room temperature, as Figure 5 shown.

[0168] Specifically, the first temperature is 180 °C to 220 °C, and the first period of time is 5 min to 30 min. Naturally dry the silicon-based cell with the formed all-inorganic perovskite layer 32, and then perform heat treatment on a heating plate at a temperature of 180 °C to 220 °C for a time of 5 min to 30 min. Then naturally cool the sample to room temperature.

[0169] Step S212, form a C 60 layer on the surface of the all-inorganic perovskite layer 32 facing away from the hole transport layer 31 by thermal evaporation; form a SnO2 thin film on the surface of the C 60 layer facing away from the all-inorganic perovskite layer 32 by atomic layer deposition; the C 60 layer and the SnO2 thin film form an electron transport layer 33.

[0170] Specifically, the thickness of the C 60 layer is 10 nm to 50 nm, the thickness of the SnO2 thin film is 10 nm to 80 nm, and the atomic layer deposition temperature is 80 °C to 200 °C.

[0171] Step S213, form a second transparent electrode 34 on the surface of the electron transport layer 33 facing away from the all-inorganic perovskite layer 32 by physical vapor deposition; form a metal grid line 35 on the surface of the second transparent electrode 34 facing away from the electron transport layer 33 by screen printing or magnetron sputtering.

[0172] Specifically, the material of the metal electrode 14 is silver, copper, aluminum, or nickel; the thickness of the metal electrode 14 is 100 nm to 300 nm; the material of the metal grid line 35 is silver, copper, aluminum, or nickel; the thickness of the metal grid line 35 is 60 nm to 120 nm.

[0173] This embodiment also provides an all-inorganic perovskite-silicon heterojunction tandem solar cell, as Figure 6 shown, the all-inorganic perovskite-silicon heterojunction tandem solar cell includes:

[0174] Silicon-based battery 100, the silicon-based battery 100 includes a silicon wafer 10, a first intrinsic passivation layer 11, a p-type doping layer 12, and a first transparent electrode 13 laminated on one side of the silicon wafer 10, and a second intrinsic passivation layer 21, an n-type doping layer 22, and a tunneling conductive layer 23 laminated on the other side of the silicon wafer 10; the surface of the silicon-based battery is a matte surface at least on one side of the tunneling conductive layer 23;

[0175] A hole transport layer 31, located on the surface of the tunneling conductive layer 23 facing away from the n-type doping layer 22;

[0176] An all-inorganic perovskite layer 32, located on the surface of the hole transport layer 31 facing away from the tunneling conductive layer 23; the all-inorganic perovskite layer 32 is suitable for being formed by an electrochemical deposition process;

[0177] An electron transport layer 33, located on the surface of the all-inorganic perovskite layer 32 facing away from the hole transport layer 31;

[0178] A second transparent electrode 34, located on the surface of the electron transport layer 33 facing away from the all-inorganic perovskite layer 32.

[0179] In some alternative embodiments, the materials of the first intrinsic passivation layer 11 and the second intrinsic passivation layer 21 are intrinsic hydrogenated amorphous silicon;

[0180] The material of the n-type doping layer 22 is phosphorus-doped hydrogenated microcrystalline silicon or phosphorus-doped hydrogenated microcrystalline silicon;

[0181] The material of the p-type doping layer 12 is boron-doped hydrogenated microcrystalline silicon or boron-doped hydrogenated microcrystalline silicon;

[0182] The materials of the first transparent electrode 13 and the second transparent electrode 34 are ITO, IZO, IWO or AZO;

[0183] The material of the tunneling conductive layer 23 is a transparent conductive oxide or a metal;

[0184] The material of the hole transport layer 31 is NiO x , CuO, MoO3 or V2O5;

[0185] The material of the all-inorganic perovskite layer 32 is CsPbCl x Br y I 3-x-y Or CsPbClBr3I;

[0186] The electron transport layer 33 includes a laminated C 60 layer and a SnO2 thin film; the C 60 layer is closer to the all-inorganic perovskite layer 32 side;

[0187] The thicknesses of the first intrinsic passivation layer 11 and the second intrinsic passivation layer 21 are 4nm to 10nm;

[0188] The thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 5 nm to 20 nm; the thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 20 nm to 40 nm;

[0189] The thickness of the boron-doped hydrogenated microcrystalline silicon is 5 nm to 20 nm; the thickness of the boron-doped hydrogenated microcrystalline silicon is 20 nm to 60 nm;

[0190] The thicknesses of the first transparent electrode 13 and the second transparent electrode 34 are 60 nm to 120 nm;

[0191] C 60 The thickness of the C layer is 10 nm to 50 nm, and the thickness of the SnO2 thin film is 10 nm to 80 nm.

[0192] In some alternative embodiments, the all-inorganic perovskite-silicon heterojunction tandem solar cell further includes:

[0193] A metal electrode 14, located on the surface of the first transparent electrode 13 on the side facing away from the p-type doped layer 12;

[0194] A metal grid line 35, located on the surface of the second transparent electrode 34 on the side facing away from the electron transport layer 33;

[0195] The material of the metal electrode 14 is silver, copper, aluminum or nickel; the thickness of the metal electrode 14 is 100 nm to 300 nm;

[0196] The material of the metal grid line 35 is silver, copper, aluminum or nickel; the thickness of the metal grid line 35 is 60 nm to 120 nm.

[0197] In the description of this specification, the descriptions with reference to terms such as "this embodiment", "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0198] In the above description, technical details such as the composition and etching of each layer are not elaborated in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of the required shapes. Additionally, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. Moreover, although the embodiments are described separately above, this does not mean that the measures in each embodiment cannot be advantageously combined and used.

[0199] The above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the above specific embodiments, and various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can also be included, and the protection scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell, characterized in that: include: A silicon bottom cell is provided, the silicon bottom cell comprising a silicon wafer, a first intrinsic passivation layer, a p-type doping layer, and a first transparent electrode stacked on one side of the silicon wafer, and a second intrinsic passivation layer, an n-type doping layer, and a tunneling conductive layer stacked on the other side of the silicon wafer; the silicon bottom cell has a suede surface at least on one side of the tunneling conductive layer; forming a hole transport layer on a surface of the tunneling conductive layer facing away from the n-type doping layer; Forming an all-inorganic perovskite layer on the surface of the hole transport layer facing away from the tunneling conductive layer by an electrochemical deposition process; An electron transport layer and a second transparent electrode are sequentially formed on a surface of the all-inorganic perovskite layer facing away from the hole transport layer.

2. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 1, characterized in that: The step of forming an all-inorganic perovskite layer on the surface of the hole transport layer facing away from the tunneling conductive layer by using an electrochemical deposition process comprises: Forming a PbO2 thin film on the surface of the hole transport layer facing away from the tunneling conductive layer by an electrochemical deposition process; Spin coating a first solution on the surface of the PbO2 film so that the PbO2 film forms a perovskite intermediate phase; A second solution is spin-coated on the surface of the perovskite mesophase, so that the all-inorganic perovskite mesophase forms an all-inorganic perovskite layer.

3. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 2, characterized in that: The material of the hole transport layer is NiO x , CuO, MoO3 or V2O5; The step of forming a PbO2 film on the surface of the hole transport layer facing away from the tunneling conductive layer by using an electrochemical deposition process comprises: providing an electrolyte, wherein the electrolyte is an aqueous solution comprising lead acetate, lead nitrate and nitric acid; placing a silicon bottom cell having a hole transport layer formed thereon in the electrolyte; A two-electrode system is used for an electrochemical deposition process to form a PbO2 film on the surface of the hole transport layer facing away from the tunneling conductive layer.

4. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 3, characterized in that: In the electrolyte, the concentration of lead acetate is 0.05M to 0.2M, the concentration of lead nitrate is 0.1M to 0.4M, and the concentration of nitric acid is 0.05M to 0.2M; The deposition current of the electrochemical deposition process is 1 mA / cm 2 ~20mA / cm 2 , the deposition time is 10s~250s.

5. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 2, characterized in that: The first solution is a mixed ethanol solution of one or more of NH4Cl, NH4Br, NH4I and hydrobromic acid, and at least includes NH4Br. When multiple solutions are included, the proportion of NH4Br is greater than 50%; the total concentration of one or more of NH4Cl, NH4Br, NH4I is 0.05M to 0.3M; The perovskite intermediate phase is NH4Pb2Cl x Br y I 5-x-y ; The second solution is an organic solution of one or more of CsCl, CsBr, and CsI; the total concentration of CsCl, CsBr, and CsI is 0.05M to 0.3M; the solvent of the second solution is an alcohol organic solvent; The material of the all-inorganic perovskite layer is CsPbCl x Br y I 3-x-y .

6. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 5, characterized in that: The first solution is a mixed ethanol solution of NH4Br and hydrobromic acid; The perovskite intermediate phase is NH4Pb2Br5; The second solution is a methanol solution of CsBr; The material of the all-inorganic perovskite layer is CsPbBr3.

7. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 5, characterized in that: The first solution is a mixed ethanol solution of NH4Cl, NH4Br, NH4I and hydrobromic acid; the ratio of NH4Cl: NH4Br: NH4I is 1:3:1; The perovskite intermediate phase is NH4Pb2ClBr3I; The material of the all-inorganic perovskite layer is CsPbCl 0.6 Br 1.8 I 0.6 .

8. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 2, characterized in that: After the step of spin coating the second solution on the surface of the perovskite mesophase so that the all-inorganic perovskite mesophase forms an all-inorganic perovskite layer, the method further comprises: The silicon bottom cell forming the all-inorganic perovskite layer is heated to a first temperature; the temperature is maintained for a first time and then cooled to room temperature.

9. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 1, characterized in that: The electron transport layer comprises C 60 layer and SnO2 thin film; The step of sequentially forming an electron transport layer and a second transparent electrode on the surface of the all-inorganic perovskite layer facing away from the hole transport layer comprises: A C 60 layer; In the C 60 A SnO2 thin film is formed on the surface of the layer facing away from the all-inorganic perovskite layer by an atomic layer deposition process; Forming a second transparent electrode on a surface of the electron transport layer facing away from the all-inorganic perovskite layer by a physical vapor deposition process; After the step of sequentially forming an electron transport layer and a second transparent electrode on the surface of the all-inorganic perovskite layer facing away from the hole transport layer, the step further includes: Metal grid lines are formed on the surface of the second transparent electrode on the side facing away from the electron transport layer by screen printing or magnetron sputtering.

10. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 1, characterized in that: The step of providing a silicon bottom cell comprises: Provide silicon wafers; Performing a texturing process on the silicon wafer so that the silicon wafer has a first texturing surface and a second texturing surface opposite to each other; A first intrinsic passivation layer, a p-type doped layer, and a first transparent electrode are sequentially formed on the first velvet surface of the silicon wafer; a second intrinsic passivation layer, an n-type doped layer, and a tunneling conductive layer are sequentially formed on the second velvet surface of the silicon wafer; the tunneling conductive layer and the first transparent electrode are velvet surfaces.

11. The method for preparing an all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 10, characterized in that: The step of providing a silicon bottom cell also includes: A metal electrode is formed on a surface of the first transparent electrode facing away from the p-type doping layer; the metal electrode serves as a reflective layer.

12. An all-inorganic perovskite-silicon heterojunction tandem solar cell, characterized in that: include: A silicon-based cell, the silicon-based cell comprising a silicon wafer, a first intrinsic passivation layer, a p-type doping layer, and a first transparent electrode stacked on one side of the silicon wafer, and a second intrinsic passivation layer, an n-type doping layer, and a tunneling conductive layer stacked on the other side of the silicon wafer; the silicon-based cell has a velvet surface at least on one side of the tunneling conductive layer; A hole transport layer, located on a surface of the tunneling conductive layer facing away from the n-type doped layer; An all-inorganic perovskite layer is located on a surface of the hole transport layer facing away from the tunneling conductive layer; The all-inorganic perovskite layer is suitable for formation by electrochemical deposition process; An electron transport layer, located on a surface of the all-inorganic perovskite layer facing away from the hole transport layer; The second transparent electrode is located on a surface of the electron transport layer facing away from the all-inorganic perovskite layer.

13. The all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 12, characterized in that: The material of the first intrinsic passivation layer and the material of the second intrinsic passivation layer are intrinsic hydrogenated amorphous silicon; The material of the n-type doping layer is phosphorus-doped hydrogenated microcrystalline silicon or phosphorus-doped hydrogenated microcrystalline silicon; The material of the p-type doping layer is boron-doped hydrogenated microcrystalline silicon or boron-doped hydrogenated microcrystalline silicon; The material of the first transparent electrode and the material of the second transparent electrode are ITO, IZO, IWO or AZO; The material of the tunneling conductive layer is a transparent conductive oxide or a metal; The material of the hole transport layer is NiO x , CuO, MoO3 or V2O5; The material of the all-inorganic perovskite layer is CsPbCl x Br y I 3-x-y ; The electron transport layer comprises a stacked C 60 layer and SnO2 thin film; the C 60 A layer close to one side of the all-inorganic perovskite layer; The thickness of the first intrinsic passivation layer and the second intrinsic passivation layer is 4 nm to 10 nm; The thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 5 nm to 20 nm; the thickness of the phosphorus-doped hydrogenated microcrystalline silicon is 20 nm to 40 nm; The thickness of the boron-doped hydrogenated microcrystalline silicon is 5 nm to 20 nm; the thickness of the boron-doped hydrogenated microcrystalline silicon is 20 nm to 60 nm; The thickness of the first transparent electrode and the thickness of the second transparent electrode are 60nm to 120nm; The C 60 The thickness of the layer is 10nm-50nm, and the thickness of the SnO2 film is 10nm-80nm.

14. The all-inorganic perovskite-silicon heterojunction tandem solar cell according to claim 12, characterized in that: The all-inorganic perovskite-silicon heterojunction tandem solar cell further comprises: A metal electrode, located on a surface of the first transparent electrode facing away from the p-type doped layer; A metal grid line is located on a surface of the second transparent electrode facing away from the electron transport layer; The material of the metal electrode is silver, copper, aluminum or nickel; the thickness of the metal electrode is 100nm to 300nm; The material of the metal grid line is silver, copper, aluminum or nickel; the thickness of the metal grid line is 60nm-120nm.

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