Silicon nanoparticles embedded in SiO2 films with visible photoluminescence

Applying laser ablation technique, we have synthesized two types of SiO2 films that included nanometer-sized Si particles. One is synthesized by alternative deposition of Si nanoparticle layers and SiO, lavers. The synthesized film exhibits red photoluminescence (PL) with a peak energy below 1.5 eV. The other is a SiO2 film in which Si nanocrystallites precipitate. The films were synthesized by annealing at 1000 degrees C of SiOx films which are formed by laser ablation in diluted O-2 gas. The films exhibit PL with peak energies of 1.5 eV, 2.2 eV and 2.7 eV. We find that there is a narrow range of composition for efficient 1.5-eV PL. (C) 1998 Elsevier Science B.V.