On the delay time in photoluminescence of Si-nanoclusters, produced by laser ablation

The condensation of Si clusters, produced by ns-laser ablation, is complete d typically after a few mu s at sufficiently low pressure of background gas . The photoluminescence from free gas suspended Si-cluster was experimental ly observed after a long delay time of the order of a few hundred mu s. We show that this delay time is related to long cooling and crystallization pr ocesses necessary to reach the state with pronounced particle photoluminesc ence. (C) 2000 Published by Elsevier Science B.V. All rights reserved.