Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 97: Quantum Dots and Wires: Optical Properties IV (mainly Nitrides)
HL 97.4: Talk
Friday, March 30, 2012, 10:45–11:00, ER 270
Photoluminescence response of Si doped GaN nanowires to pH variations — •Jens Wallys1, Florian Furtmayr1,2, Sebastian Koslowski1, Jörg Schörmann1, Jörg Teubert1, and Martin Eickhoff1 — 1I. Physikalisches Institut, Justus-Liebig-Universität Gießen, — 2Walter Schottky Institut, Technische Universität München
GaN nanowires (NWs) feature a low density of structural defects, a high surface to volume ratio and an excellent electrochemical stability. Due to these properties they appear as promising candidates for photo electrochemical water splitting and electrochemical sensing.
In this contribution we present photoluminescence (PL) measurements performed on Si-doped GaN NW ensembles in contact with a physiological electrolyte solution of different pH. We demonstrate that the PL response to the ion concentration can be controlled by application of an external bias in a three electrode setup. A systematic investigation reveals a correlation of the pH-response with the Si-doping concentration and the average NW diameter.
The related response mechanism will be discussed in terms of surface band bending, NW diameter, external bias and non-radiative processes.