Sn2+-Stabilization in MASnI3 perovskites by superhalide incorporation

Junxiang Xiang; Kan Wang; Bin Xiang; Xudong Cui

doi:10.1063/1.5023737

Sn²⁺-Stabilization in MASnI₃ perovskites by superhalide incorporation

J Chem Phys. 2018 Mar 28;148(12):124111. doi: 10.1063/1.5023737.

Authors

Junxiang Xiang¹, Kan Wang¹, Bin Xiang¹, Xudong Cui¹

Affiliation

¹ Photonic Technology Research and Development Center, Quanzhou Normal University, 398 Donghai Main Street, Quanzhou, Fujian 362000, China.

PMID: 29604859
DOI: 10.1063/1.5023737

Abstract

Sn-based hybrid halide perovskites are a potential solution to replace Pb and thereby reduce Pb toxicity in MAPbI₃ perovskite-based solar cells. However, the instability of Sn²⁺ in air atmosphere causes a poor reproducibility of MASnI₃, hindering steps towards this goal. In this paper, we propose a new type of organic metal-superhalide perovskite of MASnI₂BH₄ and MASnI₂AlH₄. Through first-principles calculations, our results reveal that the incorporation of BH₄ and AlH₄ superhalides can realize an impressive enhancement of oxidation resistance of Sn²⁺ in MASnI₃ perovskites because of the large electron transfer between Sn²⁺ and [BH₄]^-/[AlH₄]^-. Meanwhile, the high carrier mobility is preserved in these superhalide perovskites and only a slight decrease is observed in the optical absorption strength. Our studies provide a new path to attain highly stable performance and reproducibility of Sn-based perovskite solar cells.