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Gallium oxide (Ga2O3) continues to rapidly develop as promising material platform for next-generation
power electronics adopting wider (ultrawide) bandgap semiconductors beyond SiC and GaN. This is in
large part due to the availability of high quality single crystal substrates and epilayers that have allowed
for exploration of important material properties, processing and growth recipes, and device designs.
While p-type doping remains out of reach, controllable n-type doping has now been demonstrated via a
variety of approaches and dopants, yet has remained challenging in wider-band gap alloys such as those
incorporating Al. One primary concern is the role of cation vacancies, which have been shown to be
favorable in Ga2O3 and can act as compensating centers, as well as form complexes with a variety of
defects. Here we survey the current understanding of these and other native point defects and their
interactions with other common dopants and impurities in Ga2O3, focusing on their potential optical and
electrical consequences from insights gained through first-principles-based calculations employing hybrid
functionals. We discuss how vacancies can influence defect kinetics and how their incorporation may be
influenced by growth and processing steps. These results provide guidance for controlling the
conductivity in Ga2O3 for facilitating next-generation power electronics based on this ultra-wide bandgap
semiconductor.
This work was partially performed under the auspices of the U.S. Department of Energy by Lawrence
Livermore National Laboratory under Contract DE-AC52-07NA27344 and partially supported by LLNL
LDRD funding under Project No. 22-SI-003 and 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.
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