Optoelectronic technologies are based on families of semiconductor alloys. It is rare that a new semiconductor alloy family is developed to the point where epitaxial growth is possible; since the 1950s, this has happened approximately once per decade. Here we demonstrate epitaxial thin film growth of semiconducting chalcogenide perovskite alloys in the Ba-Zr-S-Se system by gas-source molecular beam epitaxy (MBE). We stabilize the full range y = 0 ... 3 of compositions BaZrS(3−y)Sey in the perovskite structure, up to and including BaZrSe3, by growing on BaZrS3 epitaxial templates. The resulting films are environmentally stable and the direct band gap (Eg) varies strongly with Se content, as predicted by theory, covering the range Eg = 1.9 ... 1.4 eV for y = 0 ... 3. This creates possibilities for visible and near-infrared (VIS-NIR) optoelectronics, solid state lighting, and solar cells using chalcogenide perovskites.
@article{arxiv.2211.10787,
title = {A new semiconducting perovskite alloy system made possible by gas-source molecular beam epitaxy},
author = {Ida Sadeghi and Jack Van Sambeek and Tigran Simonian and Michael Xu and Kevin Ye and Valeria Nicolosi and James M. LeBeau and R. Jaramillo},
journal= {arXiv preprint arXiv:2211.10787},
year = {2023}
}