Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 71: Quantum Dots and Wires: Optical Properties
HL 71.3: Vortrag
Donnerstag, 10. März 2016, 10:00–10:15, H15
Time-resolved, temperature-dependent photoluminescence of F- and SiO2-capped silicon nanoparticles — Robert Niemöller, Daniel Braam, •Günther M. Prinz, and Axel Lorke — Experimentalphysik und CENIDE, Universität Duisburg-Essen
Silicon is the most important semiconductor in today’s micro-electronics. A major disadvantage is its indirect bandgap, hindering the fabrication of efficient optoelectronic devices. Instead, silicon nanoparticles show bright luminescence with high quantum yield.
Here, we present time-resolved and temperature dependent photoluminescence (PL) measurements of silicon nanoparticles, capped with fluorinated silicon oxide or silicon dioxide. Apart from a stretched exponential time decay of the PL, we observe, that the intensity for the silicon dioxide-capped nanoparticles shows a maximum at 75K, while the PL intensity for the fluorinated-shell capped silicon nanocrystals increases up to room temperature.
The measured data is fitted with a combination of two models given by Lüttjohann et al. [1] and Suemoto et al. [2]. With this combined model, we can not only simulate the time dependent recombination but also the temperature dependent PL intensity. This simulation fits the luminescence data for both types of silicon nanocrystals, explaining why the fluorinated-shell capped silicon nanocrystals exhibit better luminescence properties.
[1] S. Lüttjohann, et al., EPL 79, 37002 (2007).
[2] T. Suemoto et al., Phys. Rev. B 49, 11005 (1994).