(Invited) Point Defects and Doping in Ga2O3 and Related Alloys

Abstract

Ga2O3 and related alloys are a promising platform for realizing wide-band gap semiconductors for use in a number of next-generation electronic devices exploiting their large band gaps and controllable electrical conductivity. Ga2O3 exhibits a band gap (4.8 eV) that can be tuned by In and Al incorporation, with Al-containing alloys increasing the band gap in contrast to In incorporation. While control over defect concentrations and n-type doping of Ga2O3 is rapidly improving, the dopability of alloys has remained largely unexplored. Here we describe the behavior of point defects and n-type dopants in Ga2O3 and consider the prospects of doping in the larger-gap Al-containing alloys using first-principles modelling approaches based on hybrid functional calculations. We consider a number of conventional dopants such as Si, Ge and Sn, as well as newer dopants that have been identified as effective alternatives. These results provide guidance for doping in Ga2O3 and related alloys incorporated into heterostructure devices.This work was partially performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and partially supported by the Critical Materials Institute, an Energy Innovation Hub funded by the U.S. DOE, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office.