Oxygen-incorporated single-photon sources observed at the surface of silicon carbide crystals

Formation of high-brightness single-photon sources (SPSs) which can emit single photons at room temperature was recently confirmed in oxygen-annealed SiC semiconductors (surface SPSs.) However, the structure of the surface SPSs has not yet been clarified. To verify the incorporation of oxygen in the surface SPSs, the SPSs were formed using stable 18-Oxygen isotopes as oxidants. By comparing to the case of SPSs formed using natural oxygen, it was found that the emission spectra for the 18-O samples tended to have shorter peak wavelengths, slightly narrower peak widths, and higher intensities. Thus, it appeared that, in the case of the 18-O sample, the phonon sideband was located closer to the zero-phonon line. This suggests that oxygen was incorporated into the defects attributed to the surface SPS.journal articl