Exploring the Potential of Vacancy-Ordered Cs2PtI6 Perovskite as a Lead-Free Absorber for Next-Generation Solar Cells via Modeling and Simulation

This study explores the potential of the vacancy-ordered perovskite material Cs2PtI6, which is inorganic and lead-free, as an absorber layer in a single-junction solar cell. The research is based on modeling, simulation, and subsequent optimization of the cell structure to achieve optimal conversion efficiency. A baseline structure FTO/TiO2/Cs2PtI6/Spiro-OMeTAD/Au was designed as the starting point for simulations. The effects of various physical factors on key photovoltaic parameters were evaluated, including the thicknesses of the absorber, electron transport layer (ETL), and hole transport layer (HTL), as well as the defect density within the Cs2PtI6 material and at its interfaces with the ETL and HTL. For this purpose, a mathematical model was established to investigate the combined effects of parameters, supported by contour plot analysis. Moreover, alternative materials for the ETL and HTL, featuring different physical properties and band alignments compared to those in the baseline structure, were investigated. The study also examined how the height of the energy barrier at the rear interface between the HTL and the metal layer influences device performance. Based on these findings, an optimized structure FTO/CeO2/Cs2PtI6/Cu2O/Carbon was developed. This configuration achieved a conversion efficiency of 18.54%, demonstrating its superiority over the baseline design and other comparable solar cell architectures. Overall, this work highlights the promising potential of vacancy-ordered Cs2PtI6 perovskite and contributes to the advancement of next-generation solar cell technologies.