Modification Research On Perovskite Solar Cells By ZnO And CuSCN Nanoparticles

The introduction of additives into the perovskite precursor,that is,additive engineering,is one of the important research directions for improving the performance of perovskite solar cells.Additive engineering effectively affects the film quality of the perovskite layer from the aspects of controlling perovskite grain growth,reducing defects,inhibiting non-radiative recombination in perovskite,and enhancing stability.This paper mainly studies the application of additives in perovskite solar cells and their influence on the crystalline quality of the perovskite light absorption layer.The main contents of the work are as follows:(1)First,ZnO nanoparticles were added to the CH₃NH₃PbI₃ precursor solution to prepare a highperformance and stable PSC with a Glass/ITO/SnO₂/C CH₃NH₃PbI₃:ZnO/spiro-OMeTAD/Ag structure.Through precise adjustment of the volume ratio of ZnO and C CH₃NH₃PbI₃ precursor liquid,the effect of heterogeneous nucleation and crystallization is generated,the grain size of the perovskite film is increased,and the quality of the perovskite film is improved.The CH₃NH₃PbI₃:ZnO bulk heterojunction structure formed by doping can promote the extraction of charges from the perovskite layer and improve the effective transmission of photo-generated electrons to the ETL layer.And based on CH₃NH₃PbI₃:ZnO(6v%)thin film battery device PCE reached 17.9,the current density has also been significantly improved.In addition,the CH₃NH₃PbI₃:ZnO(6v%)thin film battery device still maintains 85%of the initial PCE after being placed in the air for 20 days,which ultimately improves the performance of the PSC.(2)CuSCN is used as an additive for the perovskite layer to prepare a highly efficient and stable PSC with a structure of Glass/ITO/SnO2/CH₃NH₃PbI₃:CuSCN/spiro-OMeTAD/Ag.The PSC device prepared by this method showed good performance,and the PCE could reach 17.42%.The research results show that an appropriate amount of CuSCN additive will produce heterogeneous nucleation and induce crystallization during the crystallization process of the perovskite precursor film,increase the grain size of the perovskite film,and form a light-absorbing layer with better morphology.The CH₃NH₃PbI₃:CuSCN bulk heterojunction structure formed by CuSCN doping can promote the extraction of holes from the perovskite layer and improve the effective transmission of photo-generated holes to the HTL layer.In addition,due to the large grain size of the CH₃NH₃PbI₃:CuSCN film,the corresponding grain boundary number is reduced,so that the penetration of the absorbed water into the perovskite layer is effectively suppressed,and the damage to the perovskite structure by the water is prevented,so that the battery The device also showed better stability.