Fig. 1
From: Optical charge state control of spin defects in 4H-SiC
Effect of near-bandgap illumination on 4H-SiC divacancies. a PL spectrum with 976 nm excitation of the various divacancies in 4H-SiC, as designated in ref. 6, without and with continuous illumination at 405 nm (≈5 mW optical power). All the observed PL lines except PL5 and PL6 are enhanced by the UV excitation, including both c axis and basal defects. b Gain in the PL signal (integrated across PL1–4) as a function of excitation wavelength (energy) around the 4H-SiC bandgap (3.28 eV at 5 K49). Power was normalized to 0.4 μW across the entire energy range. The onset of change in the curve is shifted from the bandgap energy due to absorption of longitudinal acoustic phonons (about 70–80 meV). The UV absorption and corresponding electron-hole generation rate follows the curve in red, as given in ref. 49. c Lifetime of the VV0 charge state after a 405 nm pulse at 6 K. No significant decay (standard deviation of signal is 2%) is observed after 12 h
