Influences of hydrogen ion irradiation on N_cV_si^- formation in 4H-silicon carbide

Nitrogen-vacancy (NCVSi-) center in 4H-SiC is spin defect with near-infrared luminescence at room temperature and a promising candidate for quantum technologies. This paper reports on NCVSi- center formation in N-doped 4H-SiCs by hydrogen ion irradiation and subsequent thermal annealing. It is revealed photoluminescence for NCVSi- centers suddenly appears above the fluence of 5.0 x 10(15) cm(-2) when annealed at 1000 degrees C. Appearance of a threshold fluence for their formation and/or activation has not been observed for other energetic particle irradiations. The possible mechanism is discussed based on the kinetics of hydrogen-related complexes and the majority carrier depletion caused by irradiation induced damage.