Temperature-dependent photoluminescence of Ge-rich SiO2 in the presence or absence of Er shows a crossover between defect-related (15-150 K) and Er-related (150-295 K) emission within 1525 and 1440 nm. The origin of the near-infrared defect-related bands is discussed in the light of recombination of localized excitons in luminescence centers at the Ge cluster/ SiO2 interface. Time-resolved photoluminescence further enables us to illustrate the observed 1.53μm Er emission above 150 K in terms of a phonon-assisted nonradiative energy-transfer process from the luminescence centers to the Er3+ ions. © 2009 The American Physical Society.

Aloke Kanjilal

Physics

(SoNS) School of Natural Sciences

L. Rebohle

S. Prucnal

M. Voelskow

W. Skorupa

M. Helm

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Shiv Nadar University

Physical Review B - Condensed Matter and Materials Physics

Temperature dependence of the crossover between the near-infrared Er and defect-related photoluminescence bands of Ge-rich Er-doped SiO2 layers