Luminescence properties of thin nanocrystalline silicon-carbide films fabricated by direct-beam ion deposition

Nanocomposite films containing nanocrystals of silicon and silicon carbide are fabricated by direct ion-beam deposition onto silicon substrates. The films obtained are by Raman spectroscopy and the photoluminescence method. It is found that the samples under study exhibit two photoluminescence bands, in the “red” and near-infrared (IR) (600–1000 nm) and “blue” (400–550 nm) spectral ranges, which are accounted for by, respectively, the radiative recombination of excitons in silicon nanocrystals and radiative transitions between levels related to local centers (defects) on the surface of silicon nanocrystals and in the surrounding matrix. Short-duration treatment of the films in a solution based on hydrofluoric acid leads to modification of the emission spectrum and to an increase in the intensity of the exciton band due to the passivation of defects on the surface of silicon nanocrystals.