Photoluminescence of nanocrystalline silicon films formed by pulsed laser-assisted deposition with the introduction of carbon

The effect of carbon on the photoluminescent properties of films consisting of quantum-dimensional Si nanocrystals in the SiO_x (x → 2) matrix is studied. The spectra of time-resolved photoluminescence in the photon-energy range of 1.4–3.2 eV and the infrared-absorption spectra in the wave-number range of 650–1500 cm^?1 were measured. It is established that the introduction of carbon in the presence of oxygen in the course of the pulsed laser-assisted deposition of the films brings about the white-blue emission spectrum and also an increase in the intensity and stability of photoluminescence. The effect of carbon on the photoluminescent properties of the films is related to the formation of the SiO₂ barrier phase instead of SiO_x (1 < x < 2), saturation of silicon dangling bonds at the surface of Si nanocrystals with larger sizes, and mechanical strengthening of Si nanocrystals with smaller sizes.