Thickness-dependent optimization of Er3+ light emission from silicon-rich silicon oxide thin films
1 Centre de Recherche sur les Ions, les Matériaux et la Photonique (CIMAP), ENSICAEN, CNRS, CEA/IRAMIS, Université de Caen, 14050 CAEN cedex, France
2 Departament Electrònica, MIND-IN2UB, Universitat de Barcelona, Martí i Fanquès 1, 08028 Barcelona, CAT, Spain
Nanoscale Research Letters 2011, 6:395 doi:10.1186/1556-276X-6-395Published: 25 May 2011
This study investigates the influence of the film thickness on the silicon-excess-mediated sensitization of Erbium ions in Si-rich silica. The Er3+ photoluminescence at 1.5 μm, normalized to the film thickness, was found five times larger for films 1 μm-thick than that from 50-nm-thick films intended for electrically driven devices. The origin of this difference is shared by changes in the local density of optical states and depth-dependent interferences, and by limited formation of Si-based sensitizers in "thin" films, probably because of the prevailing high stress. More Si excess has significantly increased the emission from "thin" films, up to ten times. This paves the way to the realization of highly efficient electrically excited devices.