Design and optimization of Cs₂SnI₆ based inorganic perovskite solar cell model: numerical simulation

To overcome the drawbacks of high lead toxicity and poor corrosion resistance of lead-based perovskite solar cells (PSCs), and to compensate for the poor air stability of Sn 2+ compound-based perovskite, Cs 2 SnI 6 (Sn 4+ compound) is selected as the absorber for the PSC in this study. Using FTO/ETL/Cs 2 SnI 6 /HTL/Au as the model, the high-performance non-toxic inorganic PSC structure is explored through theoretical simulation and calculation by SCAPS-1D. The conduction band offsets ( CBO ) and valence band offsets ( VBO ) of commonly used electron transport layer materials (ETMs), hole transport layer materials (HTMs), and Cs 2 SnI 6 are calculated based on electron affinity potential ( χ ) and bandgap ( E g ). Then, by analyzing the pn junction composed of ETL and HTL and the bandgap structure at the n-i, i-p interfaces, the most matching n-i-p planar heterojunction model, FTO/IGZO/Cs 2 SnI 6 /Cu 2 BaSnS 4 /Au, was selected. Finally, by analyzing and adjusting the material thickness, defect density of each layer, operation temperature, the optimal performance of PSC was determined to be 30.39% power conversion efficiency ( PCE ), 1.27 V open circuit voltage ( V oc ), 28.46 mA cm −2 short circuit current ( J sc ), and 84.02% fill factor ( FF ). A new and more efficient PSC is proposed in this study, providing some terrific clues for finding high-quality alternatives to lead-based PSCs.