Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 12: Poster I
HL 12.71: Poster
Montag, 8. März 2004, 16:30–19:00, Poster A
A novel high-pressure pulsed laser deposition process for ZnO nanostructures — •E. M. Kaidashev, M. Lorenz, H. Hochmuth, D. Natusch, T. Nobis, A. Rahm, J. Lenzner, and M. Grundmann — Universität Leipzig, Fakultät für Physik und Geowissenschaften, Linnéstr. 5, D-04103 Leipzig, Germany
According to a schematic proposal of Lieber et al. [1], a novel Pulsed Laser Deposition (PLD) process for the controlled growth of ZnO nanostructures has been established. By means of an KrF excimer laser a sintered pure ZnO target is ablated in a high pressure (100 mbar) Ar gas stream. Well aligned ZnO micro- and nanocrystalline structures grow at temperature around 900∘C on thin gold template films on a-plane sapphire substrates. The main advantages of this novel PLD process are the absence of graphite in the source target which is used in the carbothermal growth as reducing agent, and the ability to grow in-situ nano-heterostructures simply by changing the laser targets. The free standing ZnO nanostructures with diameter from 0.1 to 3 µm and length up to 100 µm selectively grown on the gold coated areas of the substrate show well established hexagonal facets. Cathodoluminescence of single selected micro- and nanocrystals at 300 K demonstrates intensive ultraviolet emission around 3.25 eV and very weak (factor 10−3) green emission around 2.3 eV. This indicates a high structural quality of the as-grown ZnO microcrystals. Scanning cathodoluminescence imaging is used to characterize the homogeneity of PLD grown nanowire arrays.
Supported by the DFG within FOR 522, project P1 (Gr 1011/1-1).
[1] A. M. Morales, C. M. Lieber, Science 279 (1998) 208.