Optimization of Non-Toxic Inorganic CsSnGeI3 Perovskite Solar Cell with TiO2 and CNTS Charge Transport Layers using SCAPS-1D

Perovskite solar cells (PSCs) have shown tremendous potential in photovoltaic (PV) technology over the last decade due to their outstanding optoelectronic properties and high power conversion efficiency (PCE) of more than 25%. PSCs, on the other hand, have stability and toxicity problems, which have hampered the development of this technology. Lead (Pb) is poisonous in perovskite materials and can be substituted by non-toxic materials such as tin (Sn), germanium (Ge), bismuth (Bi), and others. Furthermore, replacing organic cations in perovskite structures with inorganic ones aids in the resolution of PSC stability problems. Using SCAPS-1D, an all-inorganic lead-free cesium tin-germanium tri-iodide (CsSnGeI3) PSC with TiO2 electron transport layer (ETL) and Kesterite CNTS as hole transport layer (HTL) is numerically modelled and optimized. The device optimization of the PSC structure TiO2/CsSnGeI3/CNTS contributed to an increase in PCE of up to 4%. The modelling results showed that the PCE of the PSC structure is 27.21%, the open-circuit voltage (Voc) is 1.15V, the short-circuit current density (Jsc) is 27.69 mA/cm2, and the fill-factor (F.F) is 84.97%. Furthermore, the impact of temperature (K), defect density (Nt), and interface defects on PSC performance is thoroughly examined. This research delves into the numerical structure and device manufacturing factors for commercializing Pb-free cesium tin-germanium-based PSC technology.