Energy transfer to Er 3+ ions in silicon‐rich‐silicon oxide: efficiency limitations

Abstract

Results of studies of excitation mechanisms of Er ions in silicon-rich silicon oxide (SRSO) are presented. It is shown that in SRSO two mechanisms of excitation are in competition: a resonant one and via defects. The resonant channel of excitation of the Er3+ 4f-shell is suppressed by the silicon excess related defects. Decay time measurements of erbium luminescence confirm the existence of isolated Er ions, characterised by a long time constant of ∼6 msec, and those strongly coupled, with the time constant of 0.5 msec, whose luminescence is quenched at 300 K. Limitations to energy transfer process due to distance dependence of the transfer rate and little spectral overlap of interacting states are discussed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)