Assessing the Behavior of Dopants and Impurities in Ga2O3 and Related Alloys Through Atomistic Simulations

Abstract

Gallium oxide (Ga2O3) and related alloys are highly promising ultra-wide band gap semiconductors for future power electronics. Beyond pure β-Ga2O3 and available polymorphs, (AlxGa1-x)2O3 (AGO) alloys enable a significant increase of the band gap to potentially access higher power device figures of merit provided that additional properties can be suitably controlled. Despite the progress with Ga2O3 and AGO alloys, understanding the nature of fundamental defects and the role of impurities and dopants is paramount to realizing the full potential of these materials. In this work we survey the current understanding of point defects in Ga2O3, focusing on their potential optical and electrical consequences from insights gained through first-principles-based calculations employing hybrid functionals. We discuss what is known about available donor and acceptor dopants, as well as their interactions with native defects and impurities incorporated through growth and processing steps. We summarize the behaviour predicted for a number of conventional and emerging dopant alternatives in Ga2O3 and AGO alloys. These results provide guidance for controlling defect populations and the electrical conductivity in Ga2O3 and related alloys and for facilitating next-generation power electronics based on this ultra-wide bandgap semiconductor family.