First-Principles Calculations of the Near-Edge Optical Properties of \b{eta}-Ga2O3

TL;DR

This study uses first-principles calculations to analyze the near-edge optical properties of {eta}-Ga2O3, revealing its potential for deep-UV detection and emission due to its electronic structure and anisotropic absorption.

Contribution

The paper provides detailed first-principles insights into the near-edge optical properties and band-gap characteristics of {eta}-Ga2O3, explaining experimental observations and its suitability for deep-UV applications.

Findings

The fundamental band gap of {eta}-Ga2O3 is indirect with a close direct gap.

Strong near-edge absorption is explained by the small energy difference between indirect and direct gaps.

Intrinsic deep-UV light emission is possible at high excitation levels.

Abstract

We use first-principles calculations based on many-body perturbation theory to investigate the near-edge electronic and optical properties of \b{eta}-Ga2O3. The fundamental band gap is indirect, but the minimum direct gap is only 29 meV higher in energy, which explains the strong near-edge absorption. Our calculations verify the anisotropy of the absorption onset and explain the range (4.4-5.0 eV) of experimentally reported band-gap values. Our results for the radiative recombination rate indicate that intrinsic light emission in the deep-UV range is possible in this indirect-gap semiconductor at high excitation. Our work demonstrates the applicability of \b{eta}-Ga2O3 for deep-UV detection and emission.