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

The condensation of Si clusters, produced by ns-laser ablation, is completed typically after a few ms at sufficiently low pressure of background gas. The photoluminescence from free gas suspended Si-cluster was experimentally observed after a long delay time of the order of a few hundred ms. We show that this delay time is related to long cooling and crystallization processes necessary to reach the state with pronounced particle photoluminescence. q2000 Published by Elsevier Science B.V. All rights reserved