Excitation and recombination dynamics of vacancy-related spin centers in silicon carbide

摘要

We generate silicon vacancy related defects in high-quality epitaxial siliconcarbide layers by means of electron irradiation. By controlling the irradiationfluence, the defect concentration is varied over several orders of magnitude.We establish the excitation profile for optical pumping of these defects andevaluate the optimum excitation wavelength of 770 nm. We also measure thephotoluminescence dynamics at room temperature and find a monoexponential decaywith a characteristic lifetime of 6.1 ns. The integrated photoluminescenceintensity depends linear on the excitation power density up to 20 kW/cm$^2$,indicating a relatively small absorption cross section of these defects.