Ir impurities in [Formula: see text] - and [Formula: see text] -[Formula: see text] and their detrimental effect on p-type conductivity

Recently gallium oxide ([Formula: see text] ) 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. [Formula: see text] -[Formula: see text] crystals are commonly grown by the Czochralski method in an iridium (Ir) crucible. For this reason, Ir is often present in [Formula: see text] crystals as an unintentional dopant. In this work the impact of Ir incorporation defects on potential p-type conductivity in [Formula: see text] -[Formula: see text] is studied by means of density functional theory. The metastable [Formula: see text] -[Formula: see text] 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 [Formula: see text] electronic structure, as well as provide interpretation for optical transitions reported in recent experiments.