Efficiency Enhancement of Lead-Free CsSnGeI3-Based Perovskite Solar Cells Using ZnSe as an Electron Transport Material and Spiro-MeOTAD as the Hole Transport Material

Perovskite solar cells are an emerging technology in the field of photovoltaic cells, they have higher efficiency, relatively low production cost, and are more versatile than traditional silicon solar cells. In this research, a cesium tin–germanium triiodide (CsSnGeI3) perovskite solar cell has achieved high power conversion efficiency and extreme air stability. In this study, lead-free Cs-based perovskite solar cells have been quantitatively analyzed to explore the effect of absorber layer thickness, defect density of the absorber layer, working temperature, series and shunt resistance, acceptor doping concentration using a solar cell capacitance simulator software. For this perovskite solar cell structure, ZnSe is used as a buffer layer, and CsSnGeI3 is used as an absorber layer. ITO material is used as an electron transport layer and Spiro-MeOTAD Transport Layer. Gold is used to make the back contact of this proposed solar cell. In this simulation, the environment-friendly perovskite solar cell achieved an efficiency of 31.22% when the thickness of the buffer and absorber layers was 0.06µm and 1.5µm. The designed outputs will be efficient for the convenient fabrication of the perovskite solar cell.