Zinc oxide sulfide electron transport layer, perovskite solar cell and preparation method thereof

Abstract

The application discloses a kind of zinc oxysulfide electron transport layer, perovskite solar cell and preparation method thereof, it is related to photovoltaic cell technical field, the preparation method of the zinc oxysulfide electron transport layer includes the following steps: providing perovskite light-absorbing layer;The surface of the perovskite light-absorbing layer is treated with oxygen plasma;By atomic layer deposition method, form zinc oxysulfide electron transport layer on the perovskite light-absorbing layer after oxygen plasma treatment.The application is treated with oxygen plasma to perovskite light-absorbing layer, and a layer of metal oxide layer will be formed on its surface, so as to produce more hydroxyl active sites.Zinc precursor can react with these hydroxyl active sites, greatly improve the reaction efficiency, form more dense zinc oxysulfide electron transport layer, so as to improve the efficiency and stability of perovskite solar cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic cells, in particular to a zinc oxysulfide electron transport layer, a perovskite solar cell and a preparation method thereof. BACKGROUND

[0002] With the development of renewable energy and the continuous pursuit of energy efficiency, photovoltaic cells as a clean and renewable energy conversion technology have attracted much attention. Metal halide perovskite solar cells have attracted worldwide attention due to their high photoelectric conversion efficiency, low raw material cost and compatibility with low-power solution preparation. They are the most promising new photovoltaic technology for industrialization.

[0003] The quality of the electron transport layer in the perovskite solar cell affects the performance of the perovskite solar cell. Therefore, providing a method for preparing a dense, uniform and defect-free electron transport layer is crucial to improve the performance and stability of the perovskite solar cell. However, the density of the electron transport layer prepared by the existing preparation method (such as solution method) still needs to be further improved.

[0004] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0005] Based on the above-mentioned deficiencies of the prior art, the purpose of the present application is to provide a zinc oxysulfide electron transport layer, a perovskite solar cell and a preparation method thereof, which aims to solve the problem that the density of the electron transport layer prepared by the existing preparation method still needs to be further improved.

[0006] The technical solutions of the present application are as follows:

[0007] In a first aspect of the present application, a preparation method of a zinc oxysulfide electron transport layer is provided, which comprises the following steps:

[0008] providing a perovskite light-absorbing layer;

[0009] oxygen plasma treating the surface of the perovskite light-absorbing layer;

[0010] forming a zinc oxysulfide electron transport layer on the perovskite light-absorbing layer after the oxygen plasma treatment by atomic layer deposition.

[0011] In a second aspect of the present application, a zinc oxysulfide electron transport layer is provided, which is prepared by the preparation method of the present application as described above.

[0012] In a third aspect of the present application, a preparation method of a perovskite solar cell is provided, which comprises the following steps:

[0013] providing a first electrode;

[0014] forming a perovskite light-absorbing layer on the first electrode;

[0015] oxygen plasma treating a surface of the perovskite light-absorbing layer;

[0016] forming a zinc oxide sulfide electron transport layer on the perovskite light-absorbing layer after the oxygen plasma treatment by atomic layer deposition;

[0017] forming a second electrode on the zinc oxide sulfide electron transport layer.

[0018] Optionally, the step of oxygen plasma treating a surface of the perovskite light-absorbing layer specifically comprises:

[0019] oxygen plasma treating a surface of the perovskite light-absorbing layer in a plasma cleaning machine for 1-10s;

[0020] The plasma cleaning machine has a radio frequency of 3.0MHz, an output power of 25-35W, and a vacuum degree of 90-100Pa.

[0021] Optionally, the step of forming a zinc oxide sulfide electron transport layer on the perovskite light-absorbing layer after the oxygen plasma treatment by atomic layer deposition specifically comprises:

[0022] Step A, placing a first electrode with a surface containing a perovskite light-absorbing layer after plasma treatment in a reaction cavity of an atomic layer deposition device, setting a substrate temperature of 80-100℃, and vacuumizing to less than 20Pa;

[0023] Step B, after a plurality of cycles, forming the zinc oxide sulfide electron transport layer, each cycle comprising repeating the following steps C to D seven times, and then repeating the following steps E to F three times;

[0024] wherein the steps C, D, E and F are specifically:

[0025] Step C, introducing a zinc precursor, with a pulse time of 10-100ms, and introducing an inert gas for cleaning for 20-50s;

[0026] Step D, introducing an oxygen precursor, with a pulse time of 10-100ms, and introducing an inert gas for cleaning for 20-50s;

[0027] Step E, introducing a zinc precursor, with a pulse time of 10-100ms, and introducing an inert gas for cleaning for 20-50s;

[0028] Step F, introducing a sulfur precursor, with a pulse time of 10-100ms, and introducing an inert gas for cleaning for 20-50s.

[0029] Optionally, the reaction cavity, the cavity pressure amplification ratio is:

[0030] Zinc precursor: oxygen precursor: sulfur precursor = 10: (7-9): (1-3).

[0031] Optionally, the zinc precursor includes at least one of dimethyl zinc, diethyl zinc, zinc acetylacetone;

[0032] The oxygen precursor includes at least one of water, ozone;

[0033] The sulfur precursor includes H2S;

[0034] The inert gas includes argon;

[0035] The material of the first electrode includes a transparent conductive oxide;

[0036] The material of the second electrode includes at least one of gold, silver, copper, and a transparent conductive oxide.

[0037] Optionally, the step of forming a perovskite light-absorbing layer on the first electrode specifically includes:

[0038] A solution containing a perovskite precursor is applied to the first electrode, and then an anti-solvent is added dropwise, and after annealing, a perovskite light-absorbing layer is obtained.

[0039] Optionally, the preparation method of the perovskite solar cell further includes a step of forming a hole transport layer between the first electrode and the perovskite light-absorbing layer, and the step specifically includes:

[0040] A solution containing a hole transport material is applied to the first electrode, and after annealing, a hole transport layer is obtained.

[0041] In a fourth aspect of the present application, a perovskite solar cell is provided, wherein the perovskite solar cell is prepared by the preparation method as described above.

[0042] Beneficial effects: In the present application, after the perovskite light-absorbing layer is treated by oxygen plasma, a metal oxide layer is formed on the surface of the perovskite light-absorbing layer, thereby generating more hydroxyl active sites, which is conducive to the growth of the subsequent atomic layer deposition method of the zinc oxide sulfide electron transport layer, and a dense electron transport layer is formed. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a preparation flow diagram of the zinc oxide sulfide electron transport layer in the embodiments of the present application.

[0044] Figure 2 It is a structure diagram of the perovskite light-absorbing layer after oxygen plasma treatment.

[0045] Figure 3A schematic diagram of the reaction between dimethyl zinc and hydroxyl groups on the surface of the perovskite light-absorbing layer after oxygen plasma treatment.

[0046] Figure 4 A schematic diagram of the preparation process of the perovskite solar cell in the embodiment of the present application. DETAILED DESCRIPTION

[0047] The present application provides a preparation method of a zinc oxide sulfide electron transport layer, a perovskite solar cell and a preparation method thereof. To make the purpose, technical solution and effects of the present application clearer and more explicit, the present application is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0049] Oxygen plasma treatment is a chemical reaction obtained by using high-energy ion state of oxygen. The application of oxygen plasma treatment involves many fields, including surface treatment, material processing and biomedical, etc. The main purpose of this technology is to improve the surface properties of materials by changing the surface chemical properties. The principle of oxygen plasma treatment is to supply high-power electricity to the flat electrode, and a high-intensity electric field is formed between the two flat electrodes, so that the electrons in the oxygen are accelerated away from the atoms and produce ionization effect, and finally form oxygen plasma. This oxygen plasma can be used to treat many different types of material surfaces. Oxygen plasma treatment can be used for surface activation, etching, deposition and functionalization of materials, etc. In terms of surface treatment, oxygen plasma treatment can be used for the treatment of metals, steels, ceramics, cellulose and other materials to enhance their surface adhesion and wettability. In terms of material processing, oxygen plasma treatment can be used for the preparation of micro-nano structures, the immobilization of biomolecules on thin films and the surface modification, etc.

[0050] Atomic layer deposition (ALD) is a surface process used to prepare thin film materials, which relies on the adsorption and reaction of reactant molecules on the surface to grow thin films. In the ALD process, a precursor molecule (usually a gas) is first introduced into the reaction chamber, allowing it to adsorb on the substrate surface and react with active sites on the substrate surface to form a monolayer film. Then by introducing another precursor molecule, it reacts with the adsorbed precursor to cover the previous molecular layer, and so on, gradually growing a thin film of the desired thickness. In the ALD process, the active sites on the substrate surface play a crucial role. These active sites are usually chemical functional groups or defects on the substrate surface that can undergo specific chemical reactions with the precursor molecules. These reaction sites determine the adsorption and reaction ability of the precursor molecules on the surface, thereby affecting the deposition rate, uniformity and structural characteristics of the thin film. Therefore, the ALD technique relies on the active sites on the substrate surface, and by adjusting the reaction conditions of the precursor molecules and the density of the active sites on the surface, precise control of the thickness, composition and structure of the thin film can be achieved, and dense, uniform and defect-free thin films can be prepared, so it can be used to prepare high-density inorganic electron transport layers. Based on this, the present application proposes a method for preparing a zinc oxide sulfide electron transport layer assisted by oxygen plasma treatment atomic layer deposition, specifically, the present application provides a method for preparing a zinc oxide sulfide electron transport layer, as shown in Figure 1 The method comprises the following steps:

[0051] S11, providing a perovskite light-absorbing layer;

[0052] S12, performing oxygen plasma treatment on the surface of the perovskite light-absorbing layer;

[0053] S13, forming a zinc oxide sulfide electron transport layer on the perovskite light-absorbing layer after the oxygen plasma treatment by an atomic layer deposition method.

[0054] As shown in Figure 2 After the perovskite light-absorbing layer is treated by oxygen plasma, a layer of metal oxide (such as PbO, etc.) is formed on its surface, thereby generating more hydroxyl active sites, which is conducive to the growth of the subsequent zinc oxide sulfide electron transport layer by the atomic layer deposition method, and a dense electron transport layer is formed.

[0055] The reasons why the metal oxide surface is easy to form more hydroxyl active sites are as follows: (1) surface activity. The metal oxide surface usually has high surface activity, which means that the atoms or ions on the surface are easy to react with the molecules in the surrounding environment. The oxygen atoms on the metal oxide surface can react with the water molecules in the environment to form hydroxyl groups; (2) electronic structure. The metal atoms on the surface of the metal oxide usually have unpaired electrons, which make the metal oxide surface have a certain reducing property, which helps the hydrogen atoms in the water molecules to react with the oxygen atoms on the surface to form hydroxyl groups. (3) adsorption property. The metal oxide surface has strong adsorption property and can adsorb water molecules, oxygen molecules and other substances. When water molecules are adsorbed to the surface of the metal oxide, the hydrogen atoms in the water molecules form hydroxyl groups with the oxygen atoms on the surface.

[0056] That is, after the perovskite light-absorbing layer is treated by oxygen plasma, a metal oxide layer is formed on the surface of the perovskite light-absorbing layer. The metal oxide layer is very easy to react with water molecules in the air to form hydroxyl groups, and then form more hydroxyl active sites on the perovskite light-absorbing layer.

[0057] In some embodiments, the step of treating the surface of the perovskite light-absorbing layer by oxygen plasma includes the following steps:

[0058] treating the surface of the perovskite light-absorbing layer by oxygen plasma in a plasma cleaning machine for 1-10s (for example, 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s or 10s, etc.);

[0059] The radio frequency of the plasma cleaning machine is 3.0MHz, the output power is 29.6W, and the vacuum degree is 90-100Pa (for example, 90Pa, 95Pa or 100Pa, etc.).

[0060] In some embodiments, the step of forming a zinc oxide sulfide electron transport layer on the perovskite light-absorbing layer treated by oxygen plasma by atomic layer deposition includes the following steps:

[0061] Step a, placing the perovskite light-absorbing layer treated by plasma into the reaction cavity of the atomic layer deposition equipment, setting the substrate temperature to 80-100℃ (for example, 80℃, 90℃ or 100℃, etc.), and vacuumizing the reaction cavity to a pressure less than 20Pa;

[0062] Step b, after a number of (for example, 10-200, specifically 20, 30, 40, 50, 60, 70, 80, 90 or 100, etc.) cycle operations, the zinc oxide sulfide electron transport layer is formed. Each cycle operation includes repeating the following steps c to d seven times, and then repeating the following steps e to f three times;

[0063] wherein step c, step d, step e and step f are specifically:

[0064] step c, the zinc precursor is introduced, the pulse time is 10-100 ms (for example, it can be 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and the inert gas is introduced for cleaning for 20-50 s (for example, it can be 20 s, 30 s, 40 s or 50 s, etc.);

[0065] step d, the oxygen precursor is introduced, the pulse time is 10-100 ms (for example, it can be 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and the inert gas is introduced for cleaning for 20-50 s (for example, it can be 20 s, 30 s, 40 s or 50 s, etc.);

[0066] step e, the zinc precursor is introduced, the pulse time is 10-100 ms (for example, it can be 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and the inert gas is introduced for cleaning for 20-50 s (for example, it can be 20 s, 30 s, 40 s or 50 s, etc.);

[0067] step f, the sulfur precursor is introduced, the pulse time is 10-100 ms (for example, it can be 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and the inert gas is introduced for cleaning for 20-50 s (for example, it can be 20 s, 30 s, 40 s or 50 s, etc.).

[0068] In some embodiments, the pressure increase ratio of the reaction cavity is:

[0069] Zinc precursor: oxygen precursor: sulfur precursor = 10: (7-9): (1-3), specifically, it can be 10:7:3, 10:8:2 or 10:9:1, etc.

[0070] In some embodiments, in step c and step e, the zinc precursor includes at least one of dimethyl zinc, diethyl zinc, zinc acetylacetone, but is not limited thereto.

[0071] In some embodiments, in step d, the oxygen precursor includes at least one of water, ozone, but is not limited thereto.

[0072] In some embodiments, in step f, the sulfur precursor includes H2S, but is not limited thereto.

[0073] In some embodiments, in steps c to f, the inert gas comprises argon, but is not limited thereto.

[0074] As shown in Figure 3 , after the perovskite light-absorbing layer is subjected to oxygen plasma treatment, a very thin metal oxide (for example, PbO, etc.) layer is formed on the surface of the perovskite light-absorbing layer, thereby generating more hydroxyl active sites. As shown in , when the zinc precursor is dimethyl zinc, the atomic layer deposition dimethyl zinc can react with these hydroxyl active sites (CH4 is removed, and is combined on the perovskite light-absorbing layer), so that the reaction efficiency is greatly improved, and a more dense zinc oxide sulfide electron transport layer is formed.

[0075] The present application also provides a zinc oxide sulfide electron transport layer, which is prepared by the preparation method as described above.

[0076] Figure 4 The present application also provides a preparation method of a perovskite solar cell, as shown in , comprising the following steps:

[0077] S21, providing a first electrode;

[0078] S22, forming a perovskite light-absorbing layer on the first electrode;

[0079] S23, performing oxygen plasma treatment on the surface of the perovskite light-absorbing layer;

[0080] S24, forming a zinc oxide sulfide electron transport layer on the perovskite light-absorbing layer subjected to the oxygen plasma treatment by an atomic layer deposition method;

[0081] S25, forming a second electrode on the zinc oxide sulfide electron transport layer.

[0082] Figure 2 As shown in Figure 3 , after the perovskite light-absorbing layer is subjected to oxygen plasma treatment, a metal oxide (for example, PbO, etc.) layer is formed on the surface of the perovskite light-absorbing layer, thereby generating more hydroxyl active sites. As shown in , when the zinc precursor is dimethyl zinc, the atomic layer deposition dimethyl zinc can react with these hydroxyl active sites (CH4 is removed, and is combined on the perovskite light-absorbing layer), so that the reaction efficiency is greatly improved, and a more dense zinc oxide sulfide electron transport layer is formed, thereby improving the efficiency and stability of the perovskite solar cell. In addition, the present application simplifies the process preparation process of the electron transport layer in the perovskite solar cell, improves the preparation efficiency and product quality, and provides a feasible technical solution for large-scale production of the perovskite solar cell.

[0083] In step S21, the material of the first electrode includes a transparent conductive oxide, and the transparent conductive oxide includes fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO). Specifically, the first electrode can be placed on a flexible substrate or a rigid substrate, and the flexible substrate includes one of polystyrene (PET) substrate, polyethylene naphthalate (PEN), and the rigid substrate includes glass.

[0084] In step S22, the step of forming a perovskite light-absorbing layer on the first electrode specifically includes:

[0085] A solution containing perovskite precursors is applied to the first electrode, and then an anti-solvent (such as chlorobenzene, etc.) is added dropwise. After annealing, a perovskite light-absorbing layer is obtained.

[0086] In some embodiments, the perovskite precursors include a first precursor and a second precursor, and the first precursor includes at least one of lead halide and tin halide, and the second precursor includes at least one of methylamine halide, formamidinium halide, and cesium halide.

[0087] In some embodiments, the tin halide includes at least one of tin chloride, tin bromide, and tin iodide, but is not limited thereto.

[0088] In some embodiments, the methylamine halide includes at least one of methylamine chloride, methylamine bromide, and methylamine iodide, but is not limited thereto.

[0089] In some embodiments, the formamidinium halide includes at least one of formamidinium chloride, formamidinium bromide, and formamidinium iodide, but is not limited thereto.

[0090] In some embodiments, the cesium halide includes at least one of cesium chloride, cesium bromide, and cesium iodide, but is not limited thereto.

[0091] In some embodiments, the solvent of the solution containing perovskite precursors includes at least one of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), but is not limited thereto.

[0092] In some embodiments, the perovskite light-absorbing layer includes a perovskite material, and the perovskite material has a chemical formula of ABX3, where A is at least one of methylamine (MA) ion, formamidinium (FA) ion, and cesium (Cs) ion, but is not limited thereto; B is at least one of lead (Pb) ion and tin (Sn) ion, but is not limited thereto; and X is at least one of halogen ions, and the halogen ions include, but are not limited to, at least one of iodine (I) ion and bromine (Br) ion.

[0093] In step S23, the step of performing oxygen plasma treatment on the surface of the perovskite light-absorbing layer specifically includes:

[0094] performing oxygen plasma treatment on the surface of the perovskite light-absorbing layer in a plasma cleaning machine for 1-10s (for example, 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s or 10s, etc.);

[0095] The radio frequency of the plasma cleaning machine is 3.0 MHz, the output power is 29.6 W, and the vacuum degree is 90-100 Pa (for example, 90 Pa, 95 Pa or 100 Pa, etc.).

[0096] In step S24, in some embodiments, the step of forming a zinc oxide sulfide electron transport layer on the perovskite light-absorbing layer after the oxygen plasma treatment by atomic layer deposition specifically comprises:

[0097] Step A, placing a first electrode containing a perovskite light-absorbing layer after plasma treatment on the surface in a reaction chamber of an atomic layer deposition device, setting the substrate temperature to 80-100°C (for example, 80°C, 90°C or 100°C, etc.), and vacuumizing to less than 20 Pa;

[0098] Step B, after performing a number of (for example, 10-200, specifically 20, 30, 40, 50, 60, 70, 80, 90 or 100, etc.) cycle operations, forming a zinc oxide sulfide electron transport layer with a thickness of 10-200 nm (for example, 10 nm, 20 nm, 50 nm, 100 nm, 150 nm or 200 nm, etc.), each cycle operation comprising repeating the following steps C to D seven times, and then repeating the following steps E to F three times;

[0099] Wherein steps C, D, E and F are specifically:

[0100] Step C, introducing a zinc precursor, with a pulse time of 10-100 ms (for example, 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and introducing an inert gas for cleaning for 20-50 s (for example, 20 s, 30 s, 40 s or 50 s, etc.);

[0101] Step D, introducing an oxygen precursor, with a pulse time of 10-100 ms (for example, 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and introducing an inert gas for cleaning for 20-50 s (for example, 20 s, 30 s, 40 s or 50 s, etc.);

[0102] Step E, the zinc precursor is introduced, the pulse time is 10-100 ms (for example, it can be 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and the inert gas is introduced for cleaning for 20-50 s (for example, it can be 20 s, 30 s, 40 s or 50 s, etc.).

[0103] Step F, the sulfur precursor is introduced, the pulse time is 10-100 ms (for example, it can be 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 60 ms, 70 ms, 80 ms, 90 ms or 100 ms, etc.), and the inert gas is introduced for cleaning for 20-50 s (for example, it can be 20 s, 30 s, 40 s or 50 s, etc.).

[0104] In some embodiments, the pressure increase ratio of the reaction cavity is:

[0105] The zinc precursor: oxygen precursor: sulfur precursor = 10: (7-9): (1-3), and specifically, it can be 10:7:3, 10:8:2 or 10:9:1, etc.

[0106] The ratio of sulfur and oxygen in the zinc oxide sulfide electron transport layer is used to control the electrical properties, optical properties and energy level structure of the thin film, and the ratio can ensure that the zinc oxide sulfide electron transport layer has good electrical properties, optical properties and appropriate energy level structure.

[0107] In some embodiments, in steps C and E, the zinc precursor includes at least one of dimethyl zinc, diethyl zinc and acetylacetone zinc, but is not limited thereto.

[0108] In some embodiments, in step D, the oxygen precursor includes at least one of water and ozone, but is not limited thereto. In some embodiments, in step F, the sulfur precursor includes H2S, but is not limited thereto.

[0109] In some embodiments, in steps C to F, the inert gas includes argon, but is not limited thereto.

[0110] In step S25, in some embodiments, the material of the second electrode includes at least one of gold, silver, copper and transparent conductive oxide (for example, AZO, etc.), but is not limited thereto.

[0111] In some embodiments, the second electrode is formed on the zinc oxide sulfide electron transport layer by a magnetron sputtering method or a vacuum evaporation method.

[0112] In some embodiments, the method for preparing the perovskite solar cell further includes a step of forming a hole transport layer between the first electrode and the perovskite light-absorbing layer, and the step specifically includes:

[0113] A solution containing a hole transport material is applied to the first electrode, and after annealing, a hole transport layer is obtained.

[0114] In some embodiments, the hole transport material includes at least one of nickel oxide, an organic polymer including but not limited to poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), or a self-assembled monolayer (SAM) material including but not limited to at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz), and [4-(7H-dibenzo[c,g]carbazol-7-yl)butyl]phosphonic acid (4PADCB).

[0115] In some embodiments, the solvent of the solution containing the hole transport material includes DMF.

[0116] The present application also provides a perovskite solar cell prepared by the preparation method as described above.

[0117] The present application is further described below through specific examples.

[0118] Unless otherwise specified, the raw materials used in the following examples are commercially available products that can be obtained through commercial channels.

[0119] Example 1

[0120] The present example provides a preparation method of a perovskite solar cell, including the following steps:

[0121] (1) A Meo-2PACz hole transport layer is prepared on an ITO glass substrate by a spin coating process, specifically including the following steps:

[0122] Meo-2PACz is added to DMF to obtain a solution with a Meo-2PACz concentration of 1 mg / mL;

[0123] 70 μL of the above solution is dropped on the ITO glass substrate, and after rotating at a speed of 3000 r / min for 30 s, annealing is performed at a temperature of 100 °C for 10 min to obtain a Meo-2PACz hole transport layer with a thickness of 20 nm;

[0124] (2) preparing the perovskite light-absorbing layer on the Meo-2PACz hole transport layer by a spin-coating process, specifically comprising the following steps:

[0125] According to the molar ratio of each element in FA 0.78 Cs 0.22 Pb(I 0.85 Br 0.15 )3, FAI, CsBr, PbI2 and PbBr2 are added to an organic solvent (the organic solvent is prepared by mixing DMF and DMSO in a volume ratio of 4:1) for mixing to obtain a perovskite precursor solution, wherein the concentration of Pb ions is 1.4 mol / mL;

[0126] 70 μL of the perovskite precursor solution is dropped on the Meo-2PACz hole transport layer, and spin-coated at a speed of 3000 r / min for 10 s, and then spin-coated at a speed of 5000 r / min for 30 s; 15 s before the end of spin-coating, anti-solvent chlorobenzene is added; after spin-coating, annealing is performed at a temperature of 100°C for 30 min to obtain a perovskite light-absorbing layer with a thickness of 400 nm, and the perovskite material in the perovskite light-absorbing layer is FA 0.78 Cs 0.22 Pb(I 0.85 Br 0.15 )3.

[0127] (3) performing oxygen plasma treatment on the perovskite light-absorbing layer, specifically comprising the following steps:

[0128] The semi-finished device obtained in step (2) is placed in a plasma cleaning machine (purchased from Shenzhen Dongxin Gaoke Automation Equipment Co., Ltd., model TS-PL02) for oxygen plasma treatment for 3 s, wherein the radio frequency of the cleaning machine is 3.0 MHz, the output power is 29.6 W, and the vacuum degree is 95 Pa, to obtain the perovskite light-absorbing layer after oxygen plasma treatment, and the perovskite light-absorbing layer after oxygen plasma treatment has a layer of metal oxide on the surface; since the content of Pb in the perovskite material is more than that of Cs, and the activity of Pb is higher than that of Cs, the main component of the metal oxide layer is PbO.

[0129] (4) depositing a zinc oxysulfide (ZnSO) electron transport layer on the surface of the perovskite light-absorbing layer after oxygen plasma treatment by atomic layer deposition, specifically comprising the following steps:

[0130] The semi-finished device obtained in step (3) is placed in the reaction cavity of an atomic layer deposition device (purchased from Jiangsu Mai Naide Micro-nano Technology Co., Ltd., model d-100-32p), and the pressure in the reaction cavity is vacuumed to less than 20 Pa, and the substrate is heated to 100°C; then 47 cycles of operation are performed, each cycle of operation comprising repeating the following steps S31 to S32 seven times, and then repeating the following steps S33 to S34 three times;

[0131] S31, dimethyl zinc was introduced, the pulse time was 20 ms, and argon was introduced for 27 s;

[0132] S32, H2O was introduced, the pulse time was 20 ms, and argon was introduced for 20 s;

[0133] S33, dimethyl zinc was introduced, the pulse time was 20 ms, and argon was introduced for 27 s;

[0134] S34, H2S was introduced, the pulse time was 20 ms, and argon was introduced for 20 s;

[0135] The cavity pressure amplitude ratio was dimethyl zinc:H2O:H2S = 10:7:3.

[0136] Finally, a ZnSO electron transport layer with a thickness of 50 nm was prepared.

[0137] (5) AZO with a thickness of 50 nm was sputtered on the surface of the ZnSO electron transport layer by a magnetron sputtering method, as a transparent electrode of the perovskite solar cell.

[0138] Example 2

[0139] The embodiment provides a preparation method of a perovskite solar cell, which is different from example 1 only in that:

[0140] In step (5), silver (Ag) with a thickness of 100 nm was grown on the surface of the ZnSO electron transport layer by a vacuum evaporation method, as a metal electrode of the perovskite battery.

[0141] Comparative Example 1

[0142] The comparative example provides a preparation method of a perovskite solar cell, which is different from example 1 only in that step (3) is not performed.

[0143] The perovskite solar cells in example 1 and comparative example 1 were tested, and the results are shown in table 1.

[0144] Table 1, test results of the perovskite solar cells in example 1 and comparative example 1

[0145]

[0146] Wherein, PCE represents photoelectric conversion efficiency, FF represents filling factor, V oc represents open circuit voltage, J sc represents short circuit current.

[0147] The results show that the perovskite solar cell prepared in example 1 has a higher PCE and V oc .

[0148] In summary, the present application provides a zinc oxysulfide electron transport layer, a perovskite solar cell and a preparation method thereof, after the perovskite light-absorbing layer is treated by oxygen plasma, a layer of metal oxide (such as PbO) is formed on the surface of the perovskite light-absorbing layer, thereby generating more hydroxyl active sites. The zinc precursor can react with these hydroxyl active sites, greatly improving the reaction efficiency, forming a more dense zinc oxysulfide electron transport layer, thereby improving the efficiency and stability of the perovskite solar cell.

[0149] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method for preparing a zinc oxide sulfur electron transport layer, characterized in that, Including the following steps: Provides a perovskite light-absorbing layer; The surface of the perovskite light-absorbing layer is subjected to oxygen plasma treatment; A zinc oxide sulfur electron transport layer was formed on the oxygen plasma-treated perovskite light-absorbing layer by atomic layer deposition.

2. A zinc oxide sulfur electron transport layer, characterized in that, It was prepared using the preparation method described in claim 1.

3. A method for fabricating a perovskite solar cell, characterized in that, Including the following steps: Provide the first electrode; A perovskite light-absorbing layer is formed on the first electrode; The surface of the perovskite light-absorbing layer is subjected to oxygen plasma treatment; A zinc oxide sulfur electron transport layer was formed on the oxygen plasma-treated perovskite light-absorbing layer by atomic layer deposition. A second electrode is formed on the zinc oxide electron transport layer.

4. The preparation method according to claim 3, characterized in that, The step of performing oxygen plasma treatment on the surface of the perovskite light-absorbing layer specifically includes: The surface of the perovskite light-absorbing layer is subjected to oxygen plasma treatment for 1-10 seconds in a plasma cleaner. The plasma cleaner has a radio frequency of 3.0MHz, an output power of 25-35W, and a vacuum degree of 90-100Pa.

5. The preparation method according to claim 3, characterized in that, The step of forming a zinc oxide sulfur electron transport layer on the oxygen plasma-treated perovskite light-absorbing layer by atomic layer deposition specifically includes: Step A: Place the first electrode with the perovskite light-absorbing layer on its surface after plasma treatment in the reaction chamber of the atomic layer deposition equipment, set the substrate temperature to 80-100℃, and evacuate to less than 20Pa. Step B: After performing several cycles of operation, the zinc oxide sulfur electron transport layer is formed. Each cycle of operation includes repeating steps C to D seven times, and then repeating steps E to F three times. Steps C, D, E, and F are specifically as follows: Step C: Introduce zinc precursor with a pulse duration of 10-100ms, and purge with inert gas for 20-50s; Step D: Introduce oxygen precursor with a pulse duration of 10-100ms, and purge with inert gas for 20-50s. Step E: Introduce zinc precursor with a pulse duration of 10-100ms, and purge with inert gas for 20-50s. Step F: Introduce sulfur precursor with a pulse duration of 10-100ms, and purge with inert gas for 20-50s.

6. The preparation method according to claim 5, characterized in that, The pressure increase ratio within the reaction chamber is: Zinc precursor: oxygen precursor: sulfur precursor = 10:(7-9):(1-3).

7. The preparation method according to claim 5, characterized in that, The zinc precursor includes at least one of dimethyl zinc, diethyl zinc, and zinc acetylacetonate. The oxygen precursor includes at least one of water and ozone; The sulfur precursor includes H2S; The inert gas includes argon; The material of the first electrode includes a transparent conductive oxide; The material of the second electrode includes at least one of gold, silver, copper, and transparent conductive oxide.

8. The preparation method according to claim 3, characterized in that, The step of forming a perovskite light-absorbing layer on the first electrode specifically includes: A solution containing a perovskite precursor is applied to the first electrode, followed by the addition of an antisolvent and annealing to obtain a perovskite light-absorbing layer.

9. The preparation method according to claim 3, characterized in that, The method for fabricating the perovskite solar cell further includes the step of forming a hole transport layer between the first electrode and the perovskite light-absorbing layer, the step specifically including: A solution containing hole transport material is applied to the first electrode, and after annealing, a hole transport layer is obtained.

10. A perovskite solar cell, characterized in that, It is prepared by the preparation method described in any one of claims 3-9.

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