Microstructure and photoluminescence performances of SiC nanocrystals embedded in SiO2 matrix by magnetron co-sputtering

Silicon carbide (SiC) nanocrystals embedded in silicon oxide (SiO2) matrix on Si(111) substrates were prepared by radio frequency (RF) magnetron co-sputtering using a SiO2/SiC composite target and adopting subsequent high temperature annealing. The microstructure and luminescent performances of the films were determined by X-ray diffraction (XRD), Fourier transform infrared transmission spectroscopy (FTIR), scanning electron microscopy (SEM) and photoluminescence (PL) measurements. The results show that the crystallization has taken place in the composite films after high temperature annealing and a part of amorphous SiC has been changed into beta-SiC nanocrystals, which are embedded in SiO2 matrix. Strong ultraviolet band (365 nm) and blue bands (458 nm and 490 nm) PL from the films, which is excited by 280 nm light, have been observed at room temperature. PL intensity increases with increasing of annealing temperature. PL is attributed to the luminescent centers formed by the Si-O related defects in the film.