Optical and structural properties of SiC nanocrystals

This paper presents the results of porous SiC characterizations using photoluminescence, scanning electronic microscopy and X-ray diffraction techniques. It is shown that the intensity of defect-related PL bands (2.13 and 2.54 eV) increases monotonically with PSiC thickness rise from 2.0 up to 12.0 μm. These luminescence centers are assigned to surface defects which appear at the PSiC etching process. Intensity enhancement for exciton-related PL bands (2.84, 3.04 and 3.24 eV ) is attributed to the exciton recombination rate increasing as result of electron-hole confinement realization in big size SiC NCs (6H-PSiC with inclusions of 15R- and 4H-PSiC) and/or quantum confinement exciton recombination in small-size 4H-PSiC NCs.