Regensburg 2007 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 6: Quantum dots and wires: preparation and characterization I
HL 6.6: Talk
Monday, March 26, 2007, 12:15–12:30, H15
Self-organised growth of InN-nanocolumns by MBE — •Christian Denker1, Joerg Malindretos1, Henning Schuhmann1, Michael Seibt1, Angela Rizzi1, Núria Garro2, and Andrés Cantarero2 — 1IV. Physikalisches Institut and Virtual Institute of Spin Electronics (VISel), Georg-August Universität Göttingen, 37077 Göttingen, Germany — 2Material Science Institute, University of Valencia, PO Box 22085, 46071 Valencia, Spain
InN nanocolumns (NCs) are an attractive system for light harvesting applications. Our aim is to investigate the optical and electrical properties of nanorod ensembles and of single objects. An electron accumulation layer is known to be formed at the surface of epitaxial thin layers due to Fermi level pinning and should therefore facilitate the electrical contacting of the nanorods. InN-NCs were grown on p-Si(111) by plasma assisted MBE. In dependence on the growth parameters four different growth regimes were identified, according to the final shape of the NCs: broadened, tapered, uniform, tapered as well as long uniform rods. The early stages of nucleation have been analysed and correlated to the final shape distribution of the NCs. Nanorods with diameters of 20-250 nm and lengths up to 1.75 µ m have been grown. The aspect ratio (length-to-diameter) reaches values of 45. HR-TEM images show a perfect crystal quality. Additionally we will present I-U-characteristics of a single NC contacted by Focused Ion Beam and e-beam lithography. First results show a resistance of a single object in the order of kΩ. Micro-Raman and micro-PL measurements will provide an insight into the optical properties of InN-NC-ensembles and single objects.