Energetics and electronic structure of native point defects in ${\alpha}$-Ga2O3

TL;DR

This study uses first-principles calculations to analyze native point defects in ${ m oldsymbol{eta}}$-Ga2O3, revealing how defect formation energies and charge states influence doping and electronic properties under different growth conditions.

Contribution

It provides detailed insights into defect energetics and charge transition levels in ${ m oldsymbol{eta}}$-Ga2O3, guiding doping strategies for electronic applications.

Findings

Negatively-charged Ga vacancy dominates near conduction band edge.

Positively-charged Ga interstitial dominates near valence band edge.

Ga-rich conditions favor n-type doping by suppressing Ga vacancy formation.

Abstract

We report first-principles calculations that clarify the formation energies and charge transition levels of native point defects (Ga and O vacancies, interstitials, and a Ga vacancy-O vacancy pair) in corundum structured ${\alpha}$-Ga2O3. Either under a Ga- or O-rich growth condition, the negatively-charged Ga vacancy and the positively-charged Ga interstitial on a site surrounded by six O atoms are dominant when the Fermi level approaches the conduction and valence band edges, respectively. These defects would compensate carrier electrons and holes, respectively. Ga-rich conditions relatively suppress the formation of the Ga vacancy and, therefore, are suited for extrinsic n-type doping of ${\alpha}$-Ga2O3.