From hexagonal to rocksalt structure: A computational study of Gallium Selenide under hydrostatic pressure

TL;DR

This study uses first-principles calculations to explore how hydrostatic pressure induces a phase transition in Gallium Selenide, affecting its structural, phononic, electronic, and optical properties, with implications for pressure-controlled devices.

Contribution

It provides a detailed computational analysis of the phase transition mechanism and property changes in GaSe under pressure, advancing understanding of layered material physics.

Findings

Pressure induces a phase transition from hexagonal to rocksalt structure in GaSe.

Significant changes in electronic and optical properties occur during the transition.

The phase transformation mechanism is elucidated using the SS-NEB method.

Abstract

This article discusses the pressure-induced structural phase transition and related phonon, electronic and optical properties of hexagonal {\epsilon}-GaSe using first-principles calculations. The study focuses on optimizing geometric and electronic band structures, analyzing the charge density distributions, atomic vibrations, and phonon spectra, and characterizing the optical properties of GaSe under hydrostatic pressure. The work also includes an analysis of the phase transformation mechanism using the solid-state Nudged Elastic Band (SS-NEB) method. This research sheds light on the physics of structural phase transitions in layered materials and offers potential for the development of pressure-manipulated electronics or optoelectronics.