Optical properties of cubic and rhombohedral GeTe

TL;DR

This study investigates how the optical properties of GeTe change between cubic and rhombohedral phases, revealing significant shifts in band gap and optical behavior relevant to phase change materials.

Contribution

It provides detailed calculations of optical properties for both phases of GeTe, highlighting the impact of ferroelectric distortion on electronic and optical characteristics.

Findings

Rhombohedral distortion increases the band gap from 0.11 eV to 0.38 eV.

Significant changes in optical properties occur up to 5 eV energy range.

Results relate to bonding and phase change applications of GeTe.

Abstract

Calculations of the optical properties of GeTe in the cubic NaCl and rhombohedral ferroelectric structures are reported. The rhombohedral ferroelectric distortion increases the band gap from 0.11 eV to 0.38 eV. Remarkably, substantial changes in optical properties are found even at high energies up to 5 eV. The results are discussed in relation to the bonding of GeTe and to phase change materials based on it.