Ion Migration at Metal Halide Perovskite Grain Boundaries Elucidated with a Machine Learning Force Field.

ABSTRACT: Metal halide perovskites are promising optoelectronic materials with excellent defect tolerance in carrier recombination, believed to arise largely from their unique soft lattices. However, weak lattice interactions also promote ion migration, leading to serious stability issues. Grain boundaries (GBs) have been experimentally identified as the primary migration channels, but the relevant mechanism remains elusive. Using molecular dynamics with a machine learning force field, we directly model ion migration at a common CsPbBr₃ GB. We demonstrate that the as-built GB model, containing 6400 atoms, experiences structural reconstruction over several nanoseconds, and only Br atoms diffuse after that. A fraction of Br atoms near the GB either migrate toward the GB center or along the

SUBMITTER: Samatov MR 

PROVIDER: S-EPMC11664650 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature