Split Ga vacancies in n-type and semi-insulating β-Ga2O3 single crystals

We report a positron annihilation study using state-of-the-art experimental and theoretical methods in n-type and semi-insulating beta - Ga 2 O 3. We utilize the recently discovered unusually strong Doppler broadening signal anisotropy of beta - Ga 2 O 3 in orientation-dependent Doppler broadening measurements, complemented by temperature-dependent positron lifetime experiments and first principles calculations of positron-electron annihilation signals. We find that split Ga vacancies dominate the positron trapping in beta - Ga 2 O 3 single crystals irrespective of the type of dopant or conductivity, implying concentrations of at least 1 x 1 0 18 c m - 3.

Automated summary

In this study, positron annihilation was used to investigate beta-Ga2O3, revealing that split Ga vacancies are the primary trapping sites for positrons in the material, with concentrations of at least 1 x 10^18 cm^-3, regardless of dopant type or conductivity.