Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films.

ABSTRACT: Halide ion mobility in metal halide perovskites remains an intriguing phenomenon, influencing their optical and photovoltaic properties. Selective injection of holes through electrochemical anodic bias has allowed us to probe the effect of hole trapping at iodide (0.9 V) and bromide (1.15 V) in mixed halide perovskite (CH₃NH₃PbBr_1.5I_1.5) films. Upon trapping holes at the iodide site, the iodide gradually gets expelled from the mixed halide film (as iodine and/or triiodide ion), leaving behind re-formed CH₃NH₃PbBr₃ domains. The weakening of the Pb-I bond following the hole trapping (oxidation of the iodide site) and its expulsion from the lattice in the form of iodine provided further insight into the photoinduced

SUBMITTER: Samu GF 

PROVIDER: S-EPMC6624782 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature