Preparation And Stability Of Organic Inorganic Halide Perovskite Films And Solar Cells

In recent years,organic-inorganic halide perovskite solar cells have attracted extensive attention from researchers in various fields.The reasons come from two aspects,one is that solar energy is pollution-free and inexhaustible.Advanced solar energy technology will not cause secondary pollution to our living environment like traditional fossil fuels,another is the materials Advanced solar energy technology will not cause secondary pollution to our living environment like traditional fossil fuels,another is the materials of organic-inorganic halide perovskites have the advantages of flexible adjustable band gap,high photoelectric conversion efficiency?PCE?,low cost and so on.Although they have many advantages and broad development prospects,organic-inorganic halide perovskites are very sensitive to air,so it is a huge challenge to prepare perovskite films with high crystallinity,energy conversion efficiency and air stability in air ambience.The PCE of most air-processed perovskite solar cells less than 15%due to air humidity and defect density influence which cause a sharp drop in photovoltaic performance,so it is necessary to find effective ways to fabricate high quality perovskite films with large grain and high air stability.Moreover,few papers have compared the influence of conventional process of molecule/ion solution mixing-processed directly with single crystals engineering-based on the stability and other performance of metal organic-inorganic halide perovskite solar cells in ambient.In this paper,the performance of organic-inorganic halide perovskites is systematically studied by single crystal engineering method,which is mainly divided into the following three aspects:?1?Through reading a large number of foreign literatures,we get the based theory of organic-inorganic perovskite materials and perovskite solar cell devices,and then the preparation process was carefully analyzed and studied.By comparing several kinds of the perovskite crystal growth methods,we finally chose heating the saturated solution to prepare perovskite single crystal.After repeated experiments,MA_1-XFA_XPbI₃?X=0,0.4,0.8,MA is CH₃NH₃⁺,FA is NH=CHNH₃⁺?and CsPbBr₃ single crystals are synthesized eventually,the corresponding structure and performance were analyzed in depth.?2?MA_1-XFA_XPbI₃?X=0,0.4,0.8?and CsPbBr₃ single crystals are dissolved in mixed N,N-dimethylformamide?DMF?and dimethyl sulfoxide?DMSO?to form precursor,respectively.Through one-step anti-solvent spin coating in air environment,the perovskite films and solar cells of(MA_1-XFA_XPbI₃)_1.0?CsPbBr₃?_0.05?X=0,0.4,0.8?are successfully synthesized by single crystal engineering-based methods.As a result,the highest efficiency of14.9%is successfully achieved by(MA_0.2FA_0.8PbI₃)_1.0?CsPbBr₃?_0.05.05 single crystals.The(MA_0.2FA_0.8PbI₃)_1.0?CsPbBr₃?_0.05.05 perovskite device retains 86%of its original efficiency after 40 days of storage in ambient environment with a relative humidity level of 60%and room temperature without any encapsulation.?3?(MA_0.2FA_0.8PbI₃)_1.0?CsPbBr₃?_0.05perovskite component is mainly used to systematically compare the influence of conventional molecule/ion solution mixing-processed directly with single crystal engineering-based method on the stability and other performance of metal organic-inorganic halide perovskite films and solar cells in ambient.As a result,the highest efficiency of 17.17%is successfully achieved by single crystal engineering-based method,which shows an increase by 36.7%than the 12.56%PCE of the solution mixing-based ones.The perovskite device retains 72%of its original efficiency after 40 days of storage by single crystal engineer-based method in ambient environment with a relative humidity level of 60%and room temperature without any encapsulation.At the same time,we explore the influence of different anti-solvents including CB?chlorobenzene?,EA?methylformate?andCB:EA=1:1on(MA_0.2FA_0.8PbI₃)_1.0?CsPbBr₃?_0.05.05 single crystal perovskite thin films and solar cells.As a result,a highest efficiency of 17.17%is successfully achieved by anti-solvents of CB:EA=1:1 and the device retains 80.8%of its original efficiency after 40 days storage in ambient environment with a relative humidity level of 60%and room temperature without any encapsulation.