On relation between the 1.5 mu m Er-related emission and 9 mu m vibrational modes of oxygen in silicon

We demonstrate that excitation of Er3+ ions embedded in crystalline silicon is effectively quenched when vibrational modes of interstitial oxygen are activated. In a two-color pump-probe experiment with a free-electron laser, we show that the 1.5 mu m Er-related photoluminescence diminishes as the probing beam scans through the relevant 9 mu m absorption band. Making use of time resolution of the experimental set-up, we investigate temporal aspects of this effect. (C) 2008 Elsevier B.V. All rights reserved.