Lead Free Perovskite And All Inorganic PSC Device

The progress of perovskite solar cells?PSCs?shows an unprecedentedly high rate,achieving power conversion efficiency?PCE?of more than 20%with lead-based perovskite comprising organic anion.However,the toxicity of soluble Pb²⁺and the poor device stabilities attributed to their intrinsic material instability must be resolved before stepping toward to large-scale consumer application.It is deadly desired to find environmentally friendly alternatives which retain these unique optoelectronic properties with improved stability and without the toxic lead.This work focuses on the study of lead free perovskites,and their corresponding PSC devices.The main content can be divided into the following parts:?1?Preparation of lead free perovskite CsSnBr₃ and its property investigation.PerovskiteCsSnBr₃ was easily made by a solid state reaction via sequential vacuum deposited of SnBr₂and CsBr thin films.By adjusting the solid state reaction temperature and the vapor deposition rate,a film with uniform grain distribution and high surface smooth coverage can be obtained.By a series of X-ray diffraction?XRD?study,it is found that this material possesses a cubic crystalline structure with good stability.Photophysical study demonstrated its strong optical absorption with narrow bandgap of 1.78 eV,promising for solar cell application.?2?Study of PSC devices based on CsSnBr₃.Solar cells with structure of FTO/TiO₂/CsSnBr₃/MoO₃/Al were constructed.Here thickness optimization and device physics are investigated.The optimized device achieved a PCE of 1.5%,with V_OC of 0.38 V,J_SC of 11.96 mAcm^-2,and filling factor of 0.34.?3?Preparation and property study on perovskite of CsSnI₃ and double perovskite of Cs₂SnI₆.Inthis section,after material synthesis,XRD measurement verified their structures.One of the prepared materials was tried in a solar cell with PCE of 0.014%.