Comparative study of electroluminescence from annealed amorphous SiC single layer and amorphous Si/SiC multilayers

Si quantum dots (Si QDs) films were prepared by annealing amorphous SiC single layer and amorphous Si/SiC multilayers fabricated in plasma enhanced chemical vapor deposition system. The microstructures were characterized by Raman spectroscopy as well as Fourier transforms infrared spectroscopy for both samples. It was found that Si QDs with average size of 2.7 nm were formed after annealing and the electroluminescence (EL) band centered at 650 nm can be observed at room temperature. The EL intensity from the Si/SiC multilayers was obviously improved by one order of magnitude and the corresponding EL band width was reduced compared with that from SiC single layer film. The improved electroluminescence behavior can be attributed to the formation of the denser Si QDs, good size distribution and the strong confinement effect of carriers in multilayerd structures.

► Si QDs can be formed in a-SiC single layer and a-Si/SiC multilayers (MLs).
► Si QDs has higher density and better size distribution in Si/SiC MLs.
► EL (intensity and FWHM) was improved in the Si/SiC MLs.
► EL is originated from radiative recombination of e-h pairs in Si QDs.