Ir impurities in alpha- and beta-text {Ga}_{2}text {O}_{3} and their detrimental effect on p-type conductivity

Abstract

Recently gallium oxide (text {Ga}_{2}text {O}_{3}) has become one of the most actively studied materials due to its competitive electronic properties such as wide bandgap, high breakdown field, simple control of carrier concentration, and high thermal stability. These properties make gallium oxide a promising candidate for potential applications in high-power electronic devices. beta-text {Ga}_{2}text {O}_{3} crystals are commonly grown by the Czochralski method in an iridium (Ir) crucible. For this reason, Ir is often present in text {Ga}_{2}text {O}_{3} crystals as an unintentional dopant. In this work the impact of Ir incorporation defects on potential p-type conductivity in beta-text {Ga}_{2}text {O}_{3} is studied by means of density functional theory. The metastable alpha-text {Ga}_{2}text {O}_{3} phase was investigated as the model object to understand the processes caused by iridium doping in gallium oxide-based systems. Obtained results allow us to understand better the influence of Ir on text {Ga}_{2}text {O}_{3} electronic structure, as well as provide interpretation for optical transitions reported in recent experiments.