Optical signatures of deep level defects in Ga2O3

We used depth-resolved cathodoluminescence spectroscopy and surface photovoltage spectroscopy to measure the effects of near-surface plasma processing and neutron irradiation on native point defects in beta-Ga2O3. The near-surface sensitivity and depth resolution of these optical techniques enabled us to identify spectral changes associated with removing or creating these defects, leading to identification of one oxygen vacancy-related and two gallium vacancy-related energy levels in the beta-Ga2O3 bandgap. The combined near-surface detection and processing of Ga2O3 suggests an avenue for identifying the physical nature and reducing the density of native point defects in this and other semiconductors. Published by AIP Publishing.