Fluorescent emission in different silicon carbide polytypes

Silicon carbide (SiC) is a widely used material in several industrial applications such as high power electronics, light emitting diodes, and in research application such as photo-voltaic and quantum technologies. As nanoparticles it can be synthetised in many sizes and different polytypes from 200 nm down to 1 nm. In the form of quantum dots they are used as optical biomarkers, and their emission, occurring from the blue to the orange spectral region, is based on quantum confinement effect. In this work we report on emission in the red and near infrared in different SiC polytypes, specifically in 4H, 6H and 3C. In 4H SiC the red visible emission yielded non classical light attributed to an intrinsic defect, identified as a carbon-antisite vacancy pair. Similar spectral emission was observed in 3C SiC bulk and nanoparticles, also yielding very bright single photon emission. Emission in the far red has been observed in homogeneous hetero-structure in SiC tetrapods.