Formation, Morphology and Optical Properties of SiC Nanopowder

Abstract

SiC nanopowder has been formed using an original technological approach based on grinding of bulk porous SiC nanostructures. The initial porous SiC nanostructures were obtained by anodization of n+-type 4H-SiC substrate in HF/Ethanol solution under UV illumination. Large single SiC nanoparticles (~ 30 nm in diameter) constituting the nanopowder have a porous structure which can be clearly visible. On the other hand, small single SiC nanoparticles (~ 4 nm in diameter) exhibit a clear crystalline structure. A broad and very intense luminescence band (400 – 900 nm) provided from the nanopowder corresponds to the radiative processes involving nanoparticle surface states. A smaller photoluminescence peak centred at 358 nm may correspond to radiative recombination of the photogenerated excitons confined in the individual and spatially separated 4HSiC nanoparticles.