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

Pulsed laser ablation (PLA) from a Si target in an inert He ambient has been used to produce Si/SiOx nanostructured thin ®lms on Si substrates. After the ®lm exposition to atmospheric air, they exhibited photoluminescence (PL) signals with peak energy between 1.58 and 2.15 eV. It was found that both natural and thermal oxidation of the ®lms can cause dramatic changes in PL properties giving rise to the appearance or considerable enhancement of ®xed PL peaks around 1.6±1.65 and 2.2± 2.25 eV. Quite different time-dependent PL degradation behavior under continuous laser irradiation gives an evidence for different mechanisms responsible for the PL peaks. Possible origins of PL are discussed. # 2000 Elsevier Science B.V. All rights reserved.