Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 41: Quantum Dots and Wires: Preparation and Characterization II
HL 41.4: Vortrag
Mittwoch, 24. März 2010, 11:45–12:00, H13
MBE grown InN nanowires: Doping effects of Si and Mg — •Tobias Gotschke1, Friederich Limbach1, Roberta Caterino1, Toma Stoica1, Eike Oliver Schäfer-Nolte1, Raffaella Calarco1, and Elli Sutter2 — 1Institute of Bio- and Nanosystems (IBN-1) Research Centre Jülich GmbH, D-52425 Jülich, and JARA- Fundamentals of Future Information Technology, Germany — 2Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
Si and Mg doped InN nanowires (NWs) were grown by plasma assisted molecular beam epitaxy on Si(111) substrates under nitrogen rich conditions. Influence of dopant flux, substrate temperature and In flux were investigated by means of SEM, PL and Raman. We can show that Si doped InN nanowires can be grown at higher substrate temperatures than the undoped once. By carefully choosing growth parameters the fabricated Si doped nanowires can be optimized in terms of morphology yielding to well separate nanowires with high aspect ratio and smooth sidewalls. The growth parameters chosen for the realization of Mg doped nanowires are very similar to that of undoped InN NWs. Photoluminescence measurements on Si doped nanowires show a band filling effect, which indicates a successful n-doping. PL intensity, peak energy and broadening of the peaks are fluctuating by doping with Mg. An intense LO mode in Raman measurements on InN nanowires has been observed. Mg doped NWs show a narrowing of the Raman peaks. A low energy tail emerges for the LO mode upon high doping with Si.