Crystal and electronic structure of a quasi-two-dimensional semiconductor Mg$_3$Si$_2$Te$_6$

TL;DR

This paper reports the synthesis and detailed electronic and structural characterization of Mg$_3$Si$_2$Te$_6$, a quasi-two-dimensional semiconductor with a direct narrow band gap, highlighting its potential for infrared optoelectronic applications.

Contribution

The study provides the first synthesis, structural analysis, and electronic characterization of Mg$_3$Si$_2$Te$_6$, combining experimental and theoretical methods.

Findings

Mg$_3$Si$_2$Te$_6$ has a direct band gap of 1.39 eV.

It exhibits a quasi-two-dimensional layered structure.

The material is a promising candidate for infrared optoelectronic devices.

Abstract

We report the synthesis and characterization of a Si-based ternary semiconductor Mg$_3$Si$_2$Te$_6$, which exhibits a quasi-two-dimensional structure, where the trigonal Mg$_2$Si$_2$Te$_6$ 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 Mg$_3$Si$_2$Te$_6$ is a direct gap semiconductor with a relatively narrow gap, which is a potential candidate for infrared optoelectronic devices.