Photoluminescence decay dynamics of SiO2 films containing Si nanocrystals and Er

Photoluminescence decay dynamics of SiO2 films containing Si nanocrystals (nc-Si) and Er was studied. On increasing the Er concentration. the 1.54 mu m PL due to the intra-4f shell transition of Er3+ increased drastically, while the PL peak at 0.8 mu m due to the recombination of electron-hole pairs in nc-Si decreased and the lifetime became shorter. For the 1.54 mu m PL, PL delay was observed after the pulsed excitation of nc-Si host. The results clearly indicated that Er3+ is excited by the energy transfer from nc-Si. From the observed PL delay, the energy transfer rate frost nc-Si to Er3+ was estimated to be 5 x 10(5) s(-1). (C) 2000 Elsevier Science B.V. All rights reserved.