Chalcogenide Perovskite Thin Films with Controlled Phases for Optoelectronics

Chalcogenide perovskites exhibit promise as semiconductor materials for optoelectronics due to their adjustable bandgaps, strong absorption, reasonable carrier properties, chemical stability, and eco-friendliness. However, apart from well-studied BaZrS₃, the diversity of chalcogenide perovskite thin films remains unexplored. In this study, we achieved four controlled phases of chalcogenide perovskite thin films through pulsed laser deposition (PLD) and CS₂ annealing, which was guided by molecular dynamics simulations of phase stability. When crystallized in a distorted perovskite phase, all materials emitted visible-range photoluminescence (PL), though the PL spectra's full-width-at-half-maximum (FWHM) varied significantly, from 99 meV for SrHfS₃ to 231 meV for BaHfS₃. This variance results from differing kinetic barriers in the structural motifs of Sr and Ba compounds.