DMSO-Free Processed All-Inorganic CsSnI₃ Perovskite Solar Cells.

Perovskite solar cells (PSC) have achieved efficiencies of 84% of the Shockley–Queisser limit (the theoretical limit) in its single-junction configuration and over 76% in tandem architectures. However, the lead toxicity of PSCs remains a significant socioeconomic concern, hindering their successful market deployment. In this context, Tin-based perovskite halide (TPH) materials are being explored as an alternative to their lead-based counterparts. Among them, the all-inorganic CsSnI₃ stands out as a promising candidate due to its narrow band gap (~1.3eV), low exciton binding energy and intrinsic stability.¹ Since, we have previously reported that Dimethyl sulfoxide (DMSO), the commonly used solvent for perovskite processing, causes unwanted tin oxidation (Sn+2 to Sn+4).^2,3 This talk will comprise the DMSO-free method for processing CSSnI₃ films for photovoltaics applications. Furthermore, we introduced pyridine derivatives to improve crystallization. This approach helped to achieve over 6% efficiency for CsSnI₃ compared to over 10% DMSO-based state-of-the-art devices for CsSnI₃ perovskite solar cells.⁴ This discussion will be supported by advanced characterization tools which will pave the way for stable tin-based perovskite solar cell devices.

References
1-Wang, G., et al., “Inorganic CsSnI3 Perovskite Solar Cells: The Progress and Future Prospects.” Solar RRL, 2022 ,6(4), 2100841.
2-A.Abate et al, “A. Origin of Sn(II) Oxidation in Tin Halide Perovskites.” Mater. Adv. 2020, 1 (5), 1066– 1070,
3-A.Abate et al, “ Solvents for Processing Stable Tin Halide Perovskites” ACS Energy Letters 2021 6 (3), 959-968
4-Ye, et al., “Localized Electron Density Engineering for Stabilized B-γ CsSnI3-Based Perovskite Solar Cells with Efficiencies >10%.”ACS Energy Letters 2021 6 (4), 1480-1489.