Emission of Er- and Si-doped silicate glass films obtained by magnetron co-sputtering

Thin films of silicate glass containing Si excess and Er ions were fabricated by magnetron co-sputtering technique before being annealed at 450 °C to precipitate the Si excess in Si nanoclusters. The structural features were examined by infrared (IR) absorption spectroscopy, X-ray diffraction and transmission electron microscopy, while the emission properties were examined by photoluminescence (PL) spectroscopy. The evolution of the PL spectra obtained with both resonant (488 nm) and non resonant (476.5 nm) excitation lines, shows evidence of an important enhancement of the 1.54 μm signal when the Er ions coexist with Si nanoclusters (Si-nc), even though these latter appear non crystallized. Such results represent the first evidence of energy transfer from Si-nc to Er ions in silicate glass, and recall strikingly the similar process observed so far for the counterpart Si-rich SiO2:Er films.