Identification of charge-state-dependent single-electron levels of color centers at SiO2/SiC interface by photo-assisted capacitance–voltage measurements

Color centers at the SiO2/SiC interface have attracted attention as single-photon emitters with high photon count rates. However, the single-electron levels involved in the emission process remain unclear. In this study, defect charge states were controlled by applying a voltage and optical excitation during photo-assisted capacitance–voltage measurements. The corresponding single-electron levels were then experimentally evaluated for different charge states. The measurements revealed single-electron levels located at 0.96 and 1.19 eV above the valence-band edge for the singly negatively charged state, and at 0.96 eV for the neutral charge state. These findings provide insights into the electronic structure and emission mechanism of color centers at the SiO2/SiC interface.