Electrochemically induced iodine migration in mixed halide perovskites: suppression through chloride insertion

Junsang Cho; Jeffrey T DuBose; Preethi S Mathew; Prashant V Kamat

doi:10.1039/d0cc06217k

Electrochemically induced iodine migration in mixed halide perovskites: suppression through chloride insertion

Chem Commun (Camb). 2021 Jan 7;57(2):235-238. doi: 10.1039/d0cc06217k. Epub 2020 Dec 11.

Authors

Junsang Cho¹, Jeffrey T DuBose, Preethi S Mathew, Prashant V Kamat

Affiliation

¹ Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA. pkamat@nd.edu.

PMID: 33305300
DOI: 10.1039/d0cc06217k

Abstract

The role of chloride in improving the stability of mixed halide perovskites (MAPbCl_xBr_0.5(1-x)I_0.5(1-x))₃ is probed using spectroelectrochemistry. The injection of holes into mixed halide perovskite films through applied anodic bias results in the selective migration of iodine with ultimate expulsion into the electrolyte. Increasing the Cl content (x = 0 to 0.1) in the mixed halide perovskite suppresses the iodine mobility and thus decreases the rate of its expulsion into the solution. Implications of iodine mobility induced by hole accumulation and its impact on overall stability is discussed.