Design and fabrication of all-inorganic transport materials-based Cs2SnI6 perovskite solar cells

With lead-based perovskite materials, lead content and long-term stability are the big concerns. Recently, Cesium tin iodide (Cs2SnI6) double perovskite has gained recognition as a stable and environment-friendly photovoltaic material compared to lead-based perovskite materials. In the present study, we have investigated Cs2SnI6 based solar cell with all inorganic transport materials using SCAPS-1D. The optimized device exhibited a maximum efficiency of about 18%. Further we fabricated Cs2SnI6 perovskite films using a solution process approach, utilizing CsI and SnI4 in a 2:1 ratio. For synthesized double perovskite film, the crystallinity, morphologies, and optical characteristics were examined. Additionally, the stability analysis confirmed that the prepared perovskite films were stable for more than two months under ambient exposure. Finally, utilizing the synthesized Cs2SnI6 thin films as an absorber material, we fabricated two solar cells without and with hole transport layer (HTL), having configurations of glass/FTO/ZnO/Cs2SnI6/Ni and glass/FTO/ZnO/Cs2SnI6/ MoS2/Ni, respectively, in the ambient conditions. As a major finding, it has been observed that the inclusion of MoS2 as HTL improved overall performance, with an enhancement in the power conversion efficiency (PCE) of nearly 45% compared to the device without HTL.