Origin of point defects in β-Ga2O3 single crystals doped with Mg2+ ions

Abstract

Optical absorption and photoconductivity investigations of nominal pure and Mg2+ doped β-Ga2O3 single crystals have been carried out. Additional bands in the UV (3.6-4.6 eV) and near-IR (0.4-1.2 eV) spectral regions were found in optical absorption and photoconductivity spectra. A correlation between Mg2+ doping, annealing in oxygen atmosphere as well as optical absorption and photoconductivity bands were established in gallium oxide. Electronic transitions from shallow traps and F-centers were observed in the IR spectral region (0.4-1.2 eV). Absorption and photoconductivity in the UV region are related to deep acceptor levels created by native defects and impurities.