Chalcogenide perovskites, such as BaZrS3, are emerging semiconductors with potential for high photovoltaic power conversion efficiency. The role of defects in the efficiency of the generation and collection of photo-excited carriers has not been experimentally investigated extensively. We study the effect of processing-induced defects on the photoconductive properties of single crystals of BaZrS3. We achieved ohmic contacts to single crystals of BaZrS3 and observed positive surface photovoltage, which is typically observed in p-type semiconductors. However, mechanical polishing of BaZrS3 to remove the surface oxide leads to dense deformation grain boundaries and leads to trap-dominated photoconductive response. In comparison, ohmic contacts achieved in cleaved crystals leave fewer deformation defects and greatly improve optoelectronic properties. Defect-controlled crystal growth and contact fabrication are potentially limiting factors for achieving high photon-to-excited electron conversion efficiency in BaZrS3.
@article{arxiv.2310.03198,
title = {Photoconductive Effects in Single Crystals of BaZrS$_3$},
author = {Boyang Zhao and Huandong Chen and Ragib Ahsan and Fei Hou and Eric R Hoglund and Shantanu Singh and Huan Zhao and Han Htoon and Andrey Krayev and Maruda Shanmugasundaram and Patrick E Hopkins and Jan Seidel and Rehan Kapadia and Jayakanth Ravichandran},
journal= {arXiv preprint arXiv:2310.03198},
year = {2023}
}