A comprehensive study of the optimization and comparison of cesium halide perovskite solar cells using ZnO and Cu2FeSnS4 as charge transport layers

Abstract

To meet the increasing demand for power sources, scientists are continuously trying to improve the efficiency of solar cells. In these circumstances, Cs-based perovskites have attracted attention due to their intriguing performance. In this paper, eight different solar cells based on Cs-halide perovskite absorbers (CsPbI₃, CsPbBr₃, CsSnI₃, CsSnCl₃, Cs₂BiAgI₆, Cs₃Bi₂I₉, CsSn_0.5Ge_0.5I₃, and Cs₃Sb₂I₉) are investigated using the SCAPS-1D simulation program. Besides, ZnO and CFTS materials are proposed as promising candidates for charge transport material application, along with gold as the back contact. Initially, the impact of the absorber and the electron transport layer (ETL) thickness on the photovoltaic performance was evaluated. In addition, various parameters, such as the thickness, the donor and acceptor densities and the defect density, are investigated to locate the final optimized Cs-based structures. From this optimization, it is evident that among all the optimizing features, absorber materials and the hole transport layer (HTL) thickness, the HTL acceptor density enhanced the performance much more than the other optimizing features. Furthermore, to evaluate the characteristics of these devices, the series resistance, shunt resistance, working temperature, current–voltage density, and quantum efficiency are also simulated. Among all eight Cs-based perovskites, the ITO/ZnO/CsPbBr₃/CFTS/Au and ITO/ZnO/Cs₃Bi₂I₉/CFTS/Au devices achieved the best performance, with a conversion efficiency of 19.28% and 19.23%, respectively. Lastly, the performance of the SCAPS-1D simulator software is verified using the wxAMPS simulation program, where both yield results that are in excellent agreement. In conclusion, this research provides useful information for optimizing solar cell architectures and understanding the effects of various device components.