Optical properties of high photoluminescence silicon nanocrystals embedded in SiO2 matrices obtained by annealing hydrogen silsesquioxane

Thin films of silicon nanocrystals embedded in SiO2 matrices were prepared by annealing a photoresist of hydrogen silsesquioxane. As compared to films made by a common method of annealing SiOx (1 < x < 2), significant enhancement on photoluminescence intensity was observed. Spectroscopic ellipsometry was applied to figure out optical properties of nc-Si made from HSQ. High-resolution tunneling electron microscopy, photoluminescence and absorption spectra were taken to either confirm the fitting results of SE or characterize structural, morphological and photoluminescent properties of all samples. The deduced refractive indices of nc-Si:SiO2 films made from HSQ were given. The influence of particle size and spatial distribution of nc-Si on the extinction coefficient K and PL spectra was observed and discussed.