Femtosecond laser-induced CSiVC color centers on the surface of N-doped 4H-SiC.

Abstract

Color center ensembles-light-emitting defects in silicon carbide (SiC) have emerged as exceptional quantum emitters. Femtosecond (fs) laser processing provides a practical solution for their fabrication. While SiC color centers encompass various types, former research mostly focused on fs-laser-induced silicon-vacancy (V_Si) centers, leaving other types of centers less investigated. Here, we demonstrate the fabrication of carbon anti-site vacancy (C_SiV_C) centers on the surface of nitrogen-doped 4H-SiC using fs laser processing. Room-temperature and 1.8 K low-temperature photoluminescence tests provide evidence that the visible fluorescence originates from C_SiV_C centers. By correlating laser parameters with fluorescence spectrum, we show that single-pulse processing at energies above 400 nJ induces apparent dual emission bands peaked at 675 nm (C_SiV_C) and 900 nm (V_Si) due to the simultaneous presence of the C_SiV_C and V_Si centers in the processed region, while multi-pulse irradiation promotes the generation of C_SiV_C but causes severe damage to the substrate crystal structure. We further demonstrate the spatial patterning of color center ensembles. This work provides new, to our knowledge, insights into the engineering of fs-laser-induced color centers in SiC.