2022/11/02 by Young Won Woo, Zhenzhu Li, Woo, Young Won +7
Engineering · Materials Science · #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Perovskite Materials and Applications #Quantum Dots Synthesis And Properties
paper · pdf · doi:10.48550/arxiv.2211.00956
openalex publication_date 2022/11/02 · openalex created_date 2022/11/08 · openalex updated_date 2026/07/28
The competition between corner, edge and face-sharing octahedral networks is a cause of phase inhomogeneity in metal halide perovskite thin-films. Here we probe the charged iodine vacancy distribution and transport at the junction between cubic and hexagonal polytypes of CsPbI3 from first-principles materials modelling. We predict a lower defect formation energy in the face-sharing regions, which correlates with a longer Pb-I bond length and causes a million-fold increase in local defect concentration. These defects are predicted to be more mobile in the face-sharing regions with a reduced activation energy for vacancy-mediated diffusion. We conclude that hexagonal phase inclusions or interfaces will act as defect sinks that could trap charges and enhance current-voltage hysteresis in perovskite-based solar cells and electrical devices.