AVS 47th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP3
Formation and Evolution of Photoluminescence Si-based Nanostructured Thin Films Prepared by Laser Ablation

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: A. Kabashin, Ecole Polytechnique de Montreal, Canada
Authors: A. Kabashin, Ecole Polytechnique de Montreal, Canada
M. Meunier, Ecole Polytechnique de Montreal, Canada
R. Leonelli, University of Montreal, Canada
Correspondent: Click to Email
A method of Pulsed Laser Ablation (PLA) from a Si target in an inert He ambient has been applied in combination with different post-deposition oxidation procedures for the fabrication of Si/SiOx nanostructured films on Si substrates. The films exhibited strong visible photoluminescence (PL), which remained stable even under a prolonged continuous irradiation of the sample by an excitation laser light. The peak energy of the PL spectra could be finely varied between 1.58 and 2.15 eV by a change in the residual gas pressure during the deposition process. An effect of thermal annealing on the PL properties of the Si/SiOx films has been examined and compared with the results for Si-based films produced by thermal evaporation from a Si target in vacuum. For both deposition techniques, the thermal annealing led to a dramatic change of PL properties giving rise to a fixed PL peak around 2.2 eV. Photoluminescent properties of particles formed by PLA with natural oxidation were different than those of thermally oxidized amorphous Si films. In addition, the PL properties of the as-deposited films were found to be sensitive to surface chemistry reactions. A change of storage ambient and oxidation conditions could lead to significant changes of positions and intensities of PL peaks. Possible mechanisms of formation and evolution of PL are considered.