Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 15: Methods: Scanning Probe Techniques II
O 15.14: Vortrag
Montag, 26. März 2007, 17:30–17:45, H41
Electrical Characterization of individual nanowires with the LEEPS microscope — •Dirk Henning Weber1, André Beyer1, Berthold Völkel1, Armin Gölzhäuser1, Bianca Postels2, Andreas Waag2, Martin Gräser3, Andreas Greiner3, and Joachim Wendorff3 — 1Physik supramolekularer Systeme, Universität Bielefeld — 2Institute of Semiconductor Technology, Technische Universität Braunschweig — 3Makromolekulare Chemie, Philipps-Universität Marburg
We introduce the Low Energy Electron Point Source (LEEPS) microscope as a tool for the electrical characterization of individual free-standing nanowires. We contacted single nanowires in the LEEPS electrically and measured the specific conductivity. In addition we analysed the LEEPS image itself to extract electrical properties.
The LEEPS microscope is a projection electron microscope with electron energies from 20eV to 200eV. These electrons are emitted by a field emission tip with a radius in the atomic range. Due to the very low energy of the electrons the LEEPS image includes information about weak electrostatic fields near the object. The interference pattern of conductive nanowires appears much brighter than the interference pattern of nonconductive nanowires. With a sharp manipulation tip as a movable electrode individual nanowires were contacted electrically and the I/U curves were measured. Contacting and measurement can be observed with the LEEPS microscope subsequently. We will present I/U curves of single nanowires (i.e. ZnO, CdS, Co) as well as a comparison of LEEPS images of conductive and nonconductive wires.