| Publication No: 4073 | Search all ORC publications |
Silicon nanoclusters containing nitrogen and sensitization of erbium luminescence in SiOx:Er
M.Wojdaka, I.I.Liawb, I.Ahmada, C.J.Otonc, W.H.Lohc, A.J.Kenyona and I.W.Boydb
a. Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
b. London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, UK
c. Optoelectronics Research Centre, University of Southampton, UK
Abstract
Silicon-rich silica samples doped with erbium were grown by PECVD and characterized by photoluminescence, time-resolved photoluminescence and Fourier transform infrared spectroscopy. We observe that upon increased silicon content, the absorption spectrum reveals the formation of a SiN bond. This indicates the possible incorporation of nitrogen from the precursor N2O gas into the Si nanoclusters. The highest erbium photoluminescence is obtained for the sample with the highest silicon content and its decay characteristics are nearly single exponential with a time constant of 5 ms. In addition to erbium emission, a visible luminescence peak at about 550 nm is observed. This shows multi-exponential decay kinetics with decay times of the order of 10 ns. We propose that this emission is due to small Si nanoclusters covered by a SiN shell. From the measurements, we study a mechanism to explain the erbium excitation in this material.
Materials Science and Engineering: B (2008) Vol.146(1-3) pp.175-178
doi: 10.1016/j.mseb.2007.07.022
Click here to request a preprint of this paper. (Please mention the paper number)
Copyright University of Southampton 2006