Exciton - Light coupling in SiC nanocrystals

The paper presents the results of the SiC:N nanocrystal characterization using the methods of photoluminescence (PL) at low temperatures and X-ray diffraction (XRD). Photoluminescence study of porous SiC:N (PSiC) layers with different PSiC thicknesses reveals the intensity stimulation for the high energy PL bands. The early investigation of temperature dependences of the high energy PL bands had shown that these PL bands related to free exciton emission in the different SiC polytypes. The SiC polytypes in the original n-type SiC:N wafers and in porous SiC layers were confirmed by XRD study. The intensity enhancement of exciton-related PL bands in big size (50-250nm) SiC NCs is attributed to the realization of the exciton week confinement and exciton-light coupling in SiC NCs. The numerical simulation of exciton radiative recombination rates for the different exciton emissions has been done using a model of exciton - light coupling in SiC NCs. The experimental and numerically calculated results have been compared and discussed.