First‐principle study of the influences of point vacancies (VGa, Hi) on the photocatalytic and magnetic performance of Ga2O3:Li/Na/K systems

Abstract

Under vacuum environment, an H interstitial must exist when Ga2O3 is prepared by organometallic chemistry vapor deposition. However, few first‐principle systematic studies have been conducted on the influences of point vacancies (VGa, Hi) on the photocatalytic performance and magnetism of Ga2O3: Li or Na or K systems, and VGa is a challenge in experiments. Therefore, the first‐principle generalized gradient approximation GGA + U theory was adopted in this study. A first‐principle study was conducted on the formation energy (E f ), photocatalytic performance, and magnetism of Ga30MO48 (M = Li or Na, or K) and Ga30MHiO48 systems. Results show that under Ga‐poor conditions, the Ga30MO48 and Ga30MHiO48 systems are structurally stable and prone to doping. The Ga30MHiO48 system has lower E f , more structural stability, and easier doping than the Ga30MO48 system. The Ga30KO48 system exhibits magnetism, mainly generated by the O1−‐2p spin polarized wandering electrons near VGa. The spin polarized O2−‐2p and Ga‐4s states near VGa contribute to the hybrid coupling double‐exchange interaction. Moreover, the visible spectrum of the Ga30LiHiO48 system exhibits a significant red shift, a relatively high carrier activity, carrier separation, and relative maximum lifetime. It is relatively best as a photocatalyst.This article is protected by copyright. All rights reserved.