Role of Fermi-level depinning in quenching of V4+ related photoluminescence in semi-insulating 4H-SiC

Abstract

Abstract Vanadium atoms in 4H-silicon carbide (SiC) single crystals have prospective applications as solid-state quantum emitters, making it crucial to understand the modifications of vanadium-related optical properties due to defects in the host lattice. We introduce controlled defects using 100 MeV Ag ion irradiation and report on quenching of luminescence from neutral vanadium V4+ atoms in vanadium-doped semi-insulating (SI) 4H-SiC. A reduction in intensity from V4+ related α and β emissions, and a correlated increase in thermally stimulated current (TSC), attributed to the increase in irradiation-induced defects, are observed with increasing ion fluence (Ag cm−2). Activation energies of the defect levels involved in compensation loss are estimated from TSC. We also demonstrate a partial recovery of SI behavior after thermal annealing.