Crystal and electronic structure of a quasi-two-dimensional semiconductor Mg3Si2Te6

Abstract

We report the synthesis and characterization of a Si-based ternary semiconductor Mg3Si2Te6, which exhibits a quasi-two-dimensional structure, where the trigonal Mg2Si2Te6 layers are separated by Mg ions. Ultraviolet-visible absorption spectroscopy and density functional theory calculations were performed to investigate the electronic structure. The experimentally determined direct band gap is 1.39 eV, consistent with the value of the density function theory calculations. Our results reveal that Mg3Si2Te6 is a direct gap semiconductor, which is a potential candidate for near-infrared optoelectronic devices.