Long lifetime and efficient emission from Er3+ ions coupled to Si nanoclusters in Si-rich SiO2 layers

Reactive magnetron co-sputtering of two confocal SiO2 and Er2O3 cathodes in argon-hydrogen plasma was used to deposit Er-doped Si-rich SiO2 layers. The effects of the deposition conditions (such as RF power applied on each cathode and total plasma pressure) and annealing treatment (temperature and duration) on structural, compositional and photoluminescence (PL) properties of the layers were examined. It was found that a significant enhancement of both Er3+ PL intensity and emission lifetime up to 9 ms have been reached through monitoring of the conditions of both deposition process and annealing treatment. The effective absorption cross section and the fraction of Er ions coupled to Si clusters were analyzed. It was shown an increase of the fraction of Er3+ ions coupled to Si up to 11%.