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Synthesis and photoluminescence of ultra-pure germanium nanoparticles

2011-09-01
Chivas, R.
Yerci, Selçuk
Li, R.
Dal Negro, L.
Morse, T. F.
We have used aerosol deposition to synthesize defect and micro-strain free, ultra-pure germanium nanoparticles. Transmission electron microscopy images show a core-shell configuration with highly crystalline core material. Powder X-ray diffraction measurements verify the presence of highly pure, nano-scale germanium with average crystallite size of 30 nm and micro-strain of 0.058%. X-ray photoelectron spectroscopy demonstrates that GeOx (x <= 2) shells cover the surfaces of the nanoparticles. Under optical excitation, these nanoparticles exhibit two separate emission bands at room temperature: a visible emission at 500 nm with 0.5-1 ns decay times and an intense near-infrared emission at 1575 nm with up to similar to 20 mu s lifetime. (C) 2011 Elsevier B.V. All rights reserved.