Sensitization efficiencies in Er-doped SiOxfilms containing amorphous or crystalline silicon nanoclusters
✍ Scribed by Lenz, F. ;DeCorby, R. ;Meldrum, A.
- Book ID
- 105365312
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 298 KB
- Volume
- 206
- Category
- Article
- ISSN
- 0031-8965
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✦ Synopsis
Abstract
A suite of SiO__~x~__ films with oxygen concentrations ranging from x = 1 to 1.8 (25 at% to 3.6 at% excess silicon) were synthesized by physical vapour deposition. Erbium was incorporated by co‐evaporation of erbium metal to a concentration of about 0.2 at%. A subsequent annealing step was performed at temperatures ranging from 400 °C to 1100 °C to induce phase separation and cluster growth, and to optically activate erbium ions. This range of compositions and annealing temperatures was used to generate a fluorescence map for nanocluster‐sensitized Er^3+^. Photoluminescence (PL) spectra were measured in the visible and near‐infrared wavelength regions to explore the nature of the energy transfer between Si‐NCs and Er^3+^ ions. The highest PL intensities for undoped films occurred for samples annealed above 1000 °C, containing silicon nanocrystals. In contrast, in Er‐doped films the strongest Er^3+^ emission at 1.54 μm was observed from films annealed at temperatures below 1000 °C, demonstrating that amorphous Si nanoclusters support effective energy transfer to the Er^3+^ ions. The sensitization was most efficient when the NC peak emission wavelength was near 660 nm (1.88 eV) matching the energy of the ^4^F~9/2~ band of Er^3+^ ions in a silica host. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)