Effects of deposition and post-fabrication conditions on photoluminescent properties of nanostructured Si/SiOx films prepared by laser ablation

Pulsed Laser ablation (PLA) from a Si target in an inert He ambient has bee n used to produce Si/SiOx nanostructured thin films on Si substrates. After the film exposition to atmospheric air, they exhibited photoluminescence ( PL) signals with peak energy between 1.58 and 2.15 eV. It was found that bo th natural and thermal oxidation of the films can cause dramatic changes in PL properties giving rise to the appearance or considerable enhancement of fixed Pt peaks around 1.6-1.65 and 2.2-2.25 eV, Quite different time-depen dent PL degradation behavior under continuous laser irradiation gives an ev idence for different mechanisms responsible for the PL peaks, Possible orig ins of Pt are discussed. (C) 2000 Elsevier Science B.V. All rights reserved .