Photoluminescence spectrum of divacancy in porous and nanocrystalline cubic silicon carbide

The divacancy in silicon carbide (SiC) is a prominent solid state defect quantum bit that bears relatively strong fluorescence and optically detected magnetic resonance contrast (ODMR) at room temperature. These properties exemplify it for sensing of biological molecules. To this end, we previously developed top-down method to create divacancies cubic SiC nanoparticles (NPs) as non-perturbative ODMR biomarkers. In process, large particles are synthesized then stain etched form porous ultrasonication filtering applied the solution extract few nanometer diameter NPs. We called process no-photon exciton generation chemistry (NPEGEC). showed by adding aluminum carbon synthesis SiC, one can engineer defects NPs NPEGEC. An alternative traditional way introduce vacancies lattice irradiation. Here, compare spectra created neutron irradiation NPEGEC technique NPs, results analyzed detail means first principles calculations. find produces larger shift spectrum with residual background than which most likely caused parasitic left after annealing former sample. imply prepare may preserve bulk-like quality bits near surface.