Preparation method of perovskite thin film layer and perovskite solar cell

Abstract

The invention relates to a preparation method of a perovskite thin film layer and a perovskite solar cell, and belongs to the technical field of perovskite solar cells. The preparation method comprises the following steps: sequentially coating a perovskite wet film and a vaseline interface wet film on a to-be-coated substrate by adopting a double-die-head simultaneous coating mode, carrying out post-treatment on the coated substrate, and removing the vaseline interface wet film to obtain the perovskite thin film layer formed by the perovskite wet film. Through a double-die-head synchronous coating technology, uniform coating of the perovskite wet film and the vaseline interface wet film on the substrate is realized, invasion of environmental moisture and oxygen is effectively blocked, meanwhile, the volatilization speed of a solvent is controlled, and the uniformity and compactness of the perovskite film are ensured. Through verification of the embodiment, the perovskite thin film layer prepared by the method shows excellent crystal quality and photoelectric property, and an efficient and reliable solution is provided for commercial production of perovskite solar cells.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell technology, and specifically relates to a method for preparing a perovskite thin film layer and a perovskite solar cell. Background Technology

[0002] Small-area perovskite thin films are typically prepared using spin coating, with perovskite solar cells achieving a photoelectric conversion efficiency approaching 26%. However, spin coating is not well-suited for scaling up to module-level thin film fabrication. A widely used large-area thin film fabrication technique employs solution coating. This method utilizes a high-precision die to uniformly release a precursor solution. During the relative movement with the substrate, the solution continuously deposits and spreads evenly across the substrate surface. Combined with rapid drying methods such as heating and blowing, the solvent evaporates, and the solute quickly reaches a supersaturated state, leading to nucleation, crystal growth, and the acquisition of a uniform and dense thin film.

[0003] Wet film drying is crucial for perovskite nucleation and growth, requiring precise control of the solvent evaporation and removal process. However, the commonly used heating and blowing method is suitable for drying relatively thin wet films. Once the thickness of the wet film is increased, problems such as excessively rapid surface drying, internal solvent residue, and slow release leading to porosity arise, making it difficult to obtain large-area perovskite thin film layers with good repeatability and uniformity. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for preparing a perovskite thin film layer and a perovskite solar cell. The method employs a dual-head synchronous coating technique, sequentially coating a perovskite wet film and a Vaseline interface wet film onto a substrate. The Vaseline interface wet film not only blocks the attack of environmental moisture and oxygen on the perovskite wet film, but more importantly, it inhibits the rapid escape of solvent from the surface of the perovskite wet film, allowing the solvent in the perovskite wet film to slowly escape from the bottom up, thereby obtaining a uniform and dense large-area perovskite thin film layer.

[0005] This invention is achieved by providing a method for preparing a perovskite thin film layer, comprising the following steps: Step 1: Prepare perovskite solution and petrolatum solution separately. The molecular structure of perovskite is ABX3. Step 2: Using a dual-head simultaneous coating method, a perovskite wet film and a petrolatum interface wet film are sequentially coated on the substrate to be coated. Step 3: Post-process the coated substrate to remove the Vaseline interface wet film and obtain a perovskite thin film layer formed by the perovskite wet film. In step one, the perovskite solution is prepared by dissolving compounds with the molecular structural formulas AX and BX2 in a solvent at a 1:1 molar ratio. Here, A is any one of the monovalent organic cations containing amino, amidine, or guanidine groups, or at least one of the monovalent inorganic cations of lithium, sodium, potassium, rubidium, or cesium; B is boron, silicon, germanium, arsenic, antimony, beryllium, magnesium, calcium, strontium, barium, aluminum, indium, gallium, tin, thallium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, or nickel. The solvent is at least one of the following: copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, wherein the molar percentage of divalent lead is not less than 80%; X is at least one anion of monovalent chloride, bromide, iodide, thiocyanate, and acetate, wherein the molar percentage of iodide is not less than 80%; the solvent is at least one of the following: amide solvents, sulfone solvents, sulfoxide solvents, ester solvents, hydrocarbons, halogenated hydrocarbon solvents, alcohol solvents, ketone solvents, ether solvents, and aromatic hydrocarbon solvents.

[0006] This invention is implemented as follows, and also provides a method for preparing a perovskite thin film layer, comprising the following steps: Step 1: Prepare the first perovskite precursor solution, the second perovskite precursor solution, and the petrolatum solution respectively. The molecular structure of the first perovskite precursor is BX2, and the molecular structure of the second perovskite precursor is AX. Step 2: Using a dual-head simultaneous coating method, a perovskite first precursor wet film and a petrolatum interface wet film are sequentially coated on the substrate to be coated. Step 3: Post-process the coated substrate to remove the Vaseline interface wet film and obtain a perovskite precursor film formed from the first perovskite precursor wet film. Step 4: Coat the perovskite second precursor solution onto the perovskite precursor film, and obtain the perovskite film layer after drying and annealing. In step 1, the first perovskite precursor solution is prepared by dissolving 1 mole of a compound with the molecular formula BX2 in a solvent, and the second perovskite precursor solution is prepared by dissolving a molar of a compound with the molecular formula AX in a solvent. Here, A is any one of a monovalent organic cation containing an amino group, an amidine group, or a guanidine group, or at least one of a monovalent inorganic cation containing lithium, sodium, potassium, rubidium, or cesium; B is boron, silicon, germanium, arsenic, antimony, beryllium, magnesium, calcium, strontium, barium, aluminum, indium, gallium, tin, thallium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, or ytterbium. The solvent is at least one of the following: lutetium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, wherein the molar percentage of divalent metal lead is not less than 80%; X is at least one anion selected from the following: chloride ion, bromide ion, iodide ion, thiocyanate ion, and acetate ion, wherein the molar percentage of iodide ion is not less than 80%; the solvent is at least one of the following: amide solvent, sulfone solvent, sulfoxide solvent, ester solvent, hydrocarbon solvent, halogenated hydrocarbon solvent, alcohol solvent, ketone solvent, ether solvent, and aromatic hydrocarbon solvent.

[0007] The present invention is implemented as follows, and also provides a perovskite solar cell, including a perovskite thin film layer, which is prepared using the perovskite thin film layer preparation method described above.

[0008] Compared with the prior art, the perovskite thin film preparation method and perovskite solar cell of the present invention, through the dual-head synchronous coating method, apply a petrolatum interface wet film at the same time during the coating process of the perovskite wet film, which greatly avoids the influence of environmental humidity on the perovskite wet film, controls the escape rate of solvent in the perovskite wet film, and makes the solvent in the perovskite wet film slowly escape from bottom to top, and then removes the petrolatum interface wet film, thereby obtaining a uniform and dense large-area perovskite thin film layer. Attached Figure Description

[0009] Figure 1 This is a mirror image of the perovskite thin film layer prepared in Example 1 of the present invention; Figure 2 This is a mirror image of the perovskite thin film layer prepared in Example 2 of the present invention. Detailed Implementation

[0010] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0011] A preferred embodiment of the method for preparing the perovskite thin film layer of the present invention includes the following steps: Step 1: Prepare perovskite solution and petrolatum solution separately. The molecular formula of perovskite is ABX3. The concentration of petrolatum solution is 30 wt%, and the solvent is hexane.

[0012] Step 2: Using a dual-head simultaneous coating method, a perovskite wet film and a petrolatum interface wet film are sequentially coated on the substrate to be coated.

[0013] Step 3: Post-process the coated substrate to remove the Vaseline interface wet film and obtain a perovskite thin film layer formed by the perovskite wet film.

[0014] In step one, the perovskite solution is prepared by dissolving compounds with the molecular structural formulas AX and BX2 in a solvent at a 1:1 molar ratio. Here, A is any one of a monovalent organic cation containing an amino group, an amidine group, or a guanidine group, or at least one of a monovalent inorganic cation containing lithium, sodium, potassium, rubidium, or cesium. B is at least one of boron, silicon, germanium, arsenic, antimony, beryllium, magnesium, calcium, strontium, barium, aluminum, indium, gallium, tin, thallium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, wherein the molar percentage of divalent metal lead is not less than 80%. X is at least one anion of monovalent chloride, bromide, iodide, thiocyanate, and acetate, wherein the molar percentage of iodide is not less than 80%. The solvent is at least one of the following: amide solvents, sulfone solvents, sulfoxide solvents, ester solvents, hydrocarbons, halogenated hydrocarbon solvents, alcohol solvents, ketone solvents, ether solvents, and aromatic hydrocarbon solvents. Specifically, the solvent is at least one of N,N-dimethylformamide (DMF), caprolactam, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), ethanol, and chlorobenzene.

[0015] This invention also discloses a method for preparing a perovskite thin film layer, comprising the following steps: Step 1: Prepare a first perovskite precursor solution, a second perovskite precursor solution, and a petrolatum solution, respectively. The molecular structure of the first perovskite precursor is BX2, and the molecular structure of the second perovskite precursor is AX.

[0016] Step 2: Using a dual-head simultaneous coating method, a perovskite first precursor wet film and a petrolatum interface wet film are sequentially coated on the substrate to be coated.

[0017] Step 3: Post-process the coated substrate to remove the Vaseline interface wet film and obtain a perovskite precursor film formed from the first perovskite precursor wet film.

[0018] Step 4: Coat the perovskite second precursor solution onto the perovskite precursor film, and obtain the perovskite film layer after drying and annealing.

[0019] In step 1, the first perovskite precursor solution is prepared by dissolving 1 mole of a compound with the molecular formula BX2 in a solvent, and the second perovskite precursor solution is prepared by dissolving 1 mole of a compound with the molecular formula AX in a solvent. Here, A is any one of a monovalent organic cation containing an amino group, an amidine group, or a guanidine group, or at least one of a monovalent inorganic cation containing lithium, sodium, potassium, rubidium, or cesium. B is at least one of boron, silicon, germanium, arsenic, antimony, beryllium, magnesium, calcium, strontium, barium, aluminum, indium, gallium, tin, thallium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, wherein the molar percentage of divalent metal lead is not less than 80%. X is at least one anion of monovalent chloride, bromide, iodide, thiocyanate, and acetate, wherein the molar percentage of iodide is not less than 80%. The solvent is at least one of the following: amide solvents, sulfone solvents, sulfoxide solvents, ester solvents, hydrocarbons, halogenated hydrocarbon solvents, alcohol solvents, ketone solvents, ether solvents, and aromatic hydrocarbon solvents. Specifically, the solvent is at least one of N,N-dimethylformamide (DMF), caprolactam, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), ethanol, and chlorobenzene.

[0020] Specifically, during the dual-head coating process, the front-to-back distance between the dual heads is 1cm to 10cm, the coating rate is 100mm / min to 1000mm / min, and the temperature of the coating platform is 20℃ to 160℃.

[0021] Specifically, the post-processing includes any one of the following methods: high-temperature annealing, solvent cleaning, and vacuum evacuation.

[0022] The present invention also discloses a perovskite solar cell, comprising a perovskite thin film layer, wherein the perovskite thin film layer is prepared using the perovskite thin film layer preparation method described above.

[0023] The method for preparing the perovskite thin film layer of the present invention is further illustrated below through specific embodiments. Example 1

[0024] The first embodiment of the method for preparing the perovskite thin film layer of the present invention includes the following steps: Step 11: Dissolve 159g of methylamine hydroiodide powder and 461g of lead iodide powder in a 1-liter mixed solvent of ethylene glycol methyl ether and acetonitrile, and heat and stir until fully dissolved.

[0025] Step 12: Prepare a 30wt% petroleum jelly solution.

[0026] Step 13: Heat the coating stage to 50°C, place an FTO glass substrate coated with tin dioxide into the stage, and simultaneously coat using dual-die heads, sequentially depositing the perovskite precursor solution and petrolatum solution. The spacing between the dual-die heads is 10 mm, and the coating rate is 900 mm / min.

[0027] Step 14: Heat the substrate to 100°C for 10 minutes, allow it to cool naturally, and then clean it with hexane to remove any residual petrolatum on the surface, thus completing the preparation of the perovskite thin film layer. Example 2

[0028] A second embodiment of the method for preparing the perovskite thin film layer of the present invention includes the following steps: Step 21: Dissolve lead iodide powder and lead bromide powder in a molar ratio of 95:5 in a mixed solvent of dimethyl sulfoxide and N,N-dimethylformamide, and heat at 70°C for 2 hours to obtain a lead halide solution with a concentration of 1.0M.

[0029] Step 22: Dissolve petroleum jelly in hexane to obtain a petroleum jelly solution with a concentration of 30 wt%.

[0030] Step 23: Dissolve 90 mg formamidin hydroiodide and 9 mg methylamine hydrochloride in 1 mL of isopropanol to prepare a halide solution.

[0031] Step 24: Heat the coating stage to 50°C, place an ITO glass substrate coated with PTAA into the stage, and simultaneously coat with a dual-die head, sequentially coating with lead halide solution and petrolatum solution. The distance between the dual dies is 50 mm, and the coating rate is 600 mm / min.

[0032] Step 25: Place the substrate in a vacuum chamber, quickly evacuate to 10 Pa and maintain for 1 min. After natural cooling, wash with ether to remove residual petrolatum on the surface to obtain a lead halide thin film layer.

[0033] Step 26: Spin-coat the lead halide thin film surface with halide solution and heat at 150°C for 15 minutes to complete the preparation of the perovskite thin film.

[0034] Please refer to Figure 1 and Figure 2 As shown, the electron microscope image of the perovskite thin film layer prepared in Example 1 is as follows. Figure 1 As shown, the electron microscope image of the perovskite thin film layer prepared in Example 2 is as follows. Figure 2 As shown. From Figure 1 and Figure 2 It can be seen that the perovskite crystals in the perovskite thin film layer are uniform and dense, meeting the expectations.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a perovskite thin film layer, characterized in that, Includes the following steps: Step 1: Prepare perovskite solution and petrolatum solution separately. The molecular structure of perovskite is ABX3. Step 2: Using a dual-head simultaneous coating method, a perovskite wet film and a petrolatum interface wet film are sequentially coated on the substrate to be coated. Step 3: Post-process the coated substrate to remove the Vaseline interface wet film and obtain a perovskite thin film layer formed by the perovskite wet film. In step one, the perovskite solution is prepared by dissolving compounds with the molecular structural formulas AX and BX2 in a solvent at a 1:1 molar ratio. Here, A is any one of the monovalent organic cations containing amino, amidine, or guanidine groups, or at least one of the monovalent inorganic cations of lithium, sodium, potassium, rubidium, or cesium; B is boron, silicon, germanium, arsenic, antimony, beryllium, magnesium, calcium, strontium, barium, aluminum, indium, gallium, tin, thallium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, or nickel. The solvent is at least one of the following: copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, wherein the molar percentage of divalent lead is not less than 80%; X is at least one anion of monovalent chloride, bromide, iodide, thiocyanate, and acetate, wherein the molar percentage of iodide is not less than 80%; the solvent is at least one of the following: amide solvents, sulfone solvents, sulfoxide solvents, ester solvents, hydrocarbons, halogenated hydrocarbon solvents, alcohol solvents, ketone solvents, ether solvents, and aromatic hydrocarbon solvents.

2. A method for preparing a perovskite thin film layer, characterized in that, Includes the following steps: Step 1: Prepare the first perovskite precursor solution, the second perovskite precursor solution, and the petrolatum solution respectively. The molecular structure of the first perovskite precursor is BX2, and the molecular structure of the second perovskite precursor is AX. Step 2: Using a dual-head simultaneous coating method, a perovskite first precursor wet film and a petrolatum interface wet film are sequentially coated on the substrate to be coated. Step 3: Post-process the coated substrate to remove the Vaseline interface wet film and obtain a perovskite precursor film formed from the first perovskite precursor wet film. Step 4: Coat the perovskite second precursor solution onto the perovskite precursor film, and obtain the perovskite film layer after drying and annealing. In step 1, the first perovskite precursor solution is prepared by dissolving 1 mole of a compound with the molecular formula BX2 in a solvent, and the second perovskite precursor solution is prepared by dissolving 1 mole of a compound with the molecular formula AX in a solvent. Here, A is any one of a monovalent organic cation containing an amino group, an amidine group, or a guanidine group, or at least one of a monovalent inorganic cation containing lithium, sodium, potassium, rubidium, or cesium; B is boron, silicon, germanium, arsenic, antimony, beryllium, magnesium, calcium, strontium, barium, aluminum, indium, gallium, tin, thallium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, or ytterbium. The solvent is at least one of the following: lutetium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, wherein the molar percentage of divalent metal lead is not less than 80%; X is at least one anion selected from the following: chloride ion, bromide ion, iodide ion, thiocyanate ion, and acetate ion, wherein the molar percentage of iodide ion is not less than 80%; the solvent is at least one of the following: amide solvent, sulfone solvent, sulfoxide solvent, ester solvent, hydrocarbon solvent, halogenated hydrocarbon solvent, alcohol solvent, ketone solvent, ether solvent, and aromatic hydrocarbon solvent.

3. The method for preparing a perovskite thin film layer as described in claim 1 or 2, characterized in that, When coating with dual-die heads, the front-to-back distance between the dual dies is 1cm to 10cm, the coating rate is 100mm / min to 1000mm / min, and the temperature of the coating platform is 20℃ to 160℃.

4. The method for preparing a perovskite thin film layer as described in claim 1 or 2, characterized in that, The post-processing includes any one of the following methods: high-temperature annealing, solvent cleaning, and vacuum evacuation.

5. A perovskite solar cell, comprising a perovskite thin film layer, characterized in that, The perovskite thin film layer is prepared using the method for preparing a perovskite thin film layer as described in claim 1, 3, or 4.

6. A perovskite solar cell, comprising a perovskite thin film layer, characterized in that, The perovskite thin film layer is prepared using the method for preparing a perovskite thin film layer as described in claim 2, 3, or 4.

Images