Research On Organic/Inorganic Laminate Design Of Perovskite Solar Cells

In recent years,inorganic perovskite solar cells have become a research hotspot due to their excellent thermal stability and increasing photoelectric conversion efficiency.However,the inorganic perovskite CsPbI2Br will have a large number of surface defects during the preparation process,which will cause the non-radiative recombination of photogenerated carriers and reduce the photoelectric conversion efficiency.In this paper,the precursor ion doping method is used to prepare the CsPbI2Br perovskite film with flat surface,small defect density and large grain size,thereby reducing the current loss in the perovskite solar cells and obtaining high photoelectric conversion efficiency.On the basis again,in order to further enhance the photoelectric conversion efficiency of perovskite solar cells,this paper designs and prepares perovskite organic/inorganic tandem solar cells.The research results of the article are as follows:(1)The CsPbI2Br inorganic perovskite precursor solution doped with L-phenylalanine was annealed at a temperature of 260℃ to realize the optimized crystallization of CsPbI2Br,and successfully prepared uniformly dense,large grain size 1μm,with CsPbI2Br perovskite film with black α cubic phase structure.Finally,a CsPbI2Br perovskite solar cell with a current density of 11.6mA/cm2 and PCE 10.1%was obtained.(2)By adjusting the composition ratio of the precursor solution materials,the n-type conductivity control of CsPbI2Br and the p-type conductivity control of MAPbI3 have been successfully realized.Based on the optimized crystallization process of CsPbI2Br,a high-quality n-type CsPbI2Br film was prepared as the underlying film,and a p-type conductive MAPbI3 film was prepared on the surface by vacuum evaporation,forming a low-energy state defect and a laminated perovskite film with a grain size of 1 μm.(3)In this paper,the structure of the mutant heterojunction is proposed,and the n-CsPbI2Br/p-MAPbI3 perovskite tandem solar cell is designed and prepared.Through the method of self-doping of precursor solution elements,the position of the Fermi energy level of the perovskite material was adjusted,and uniform and dense n-type CsPbI2Br and p-type MAPbI3 films with a large grain size of 1 μm were prepared.The wxAMPS software was used to establish the physical model of the tandem solar cell,and the simulation results of the energy band position of the tandem solar cell showed that the presence of the built-in electric field in the abrupt heterojunction region had a positive separation effect on carriers.The performance of perovskite n-CsPbI2Br/p-MAPbI3 tandem solar cells and single-layer inorganic CsPbI2Br perovskite solar cells were characterized by JV characteristics:Jsc of tandem cells was 19.43 mA/cm2(relative to 18.13 mA/cm2 of single-layer inorganic CsPbI2Br)and the highest PCE is 14.06%(relative to the PCE 12.53%of the single-layer inorganic CsPbI2Br cells).