Theoretical study of a lead-free perovskite solar cell using ZnSe as ETL and PTAA as HTL

Abstract

Cesium tin-germanium triiodide (CsSn0.5Ge0.5I3) is an efficient inorganic halide perovskite with good stability that has received wide attention in recent years. In the present study, a lead-free perovskite solar cell structure was designed with zinc selenide (ZnSe) as the electron transport layer (ETL), CsSn0.5Ge0.5I3 as the perovskite absorber layer and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) as the hole transport layer (HTL). For a more practical understanding of the solar cell, several parameters such as absorber thickness, defect density, doping concentration of the absorber layer, interface defects and working point temperature were examined. The SCAPS-1D simulator was used for the analysis of the proposed device. The power conversion efficiency of the device was obtained as 23.15% with V OC = 1.07 V, J SC = 27.24 mA/cm2 and fill factor = 78.82% at an 800 nm thickness of the CsSn0.5Ge0.5I3 absorber layer. Selection of best material and easy fabrication process is necessary for development of highly efficient and environmentally friendly perovskite solar cells.