Nanosecond Dynamics of the Near-Infrared Photoluminescence of Er-Doped SiO_2 Sensitized with Si Nanocrystals

摘要

We report on an observation of a fast 1.5 μm photoluminescence band from Er~(3+) ions embedded in an SiO_2 matrix doped with Si nanocrystals, which appears and decays within the first microsecond after the laser excitation pulse. We argue that the fast excitation and quenching are facilitated by Auger processes related to transitions of confined electrons or holes between the space-quantized levels of Si nanocrystals dispersed in SiO_2. We show that a great part—about 50%-of all Er dopants is involved in these fast processes and contributes to the submicrosecond emission.