AVS 53rd International Symposium
    Electronic Materials and Processing Friday Sessions
       Session EM-FrM

Paper EM-FrM10
Electrical Transport Measurements on Conjugated Molecules using Nanogap Electrodes on Cleaved AlGaAs Planes

Friday, November 17, 2006, 11:00 am, Room 2001

Session: Molecular Electronics
Presenter: M. Tornow, Walter Schottky Institute, TU Munich, Germany
Authors: M. Tornow, Walter Schottky Institute, TU Munich, Germany
S.M. Luber, Walter Schottky Institute, TU Munich, Germany
S. Lingitz, Walter Schottky Institute, TU Munich, Germany
A.G. Hansen, Walter Schottky Institute, TU Munich, Germany
F. Zhang, Walter Schottky Institute, TU Munich, Germany
F. Scheliga, University of Hamburg, Germany
E. Thorn-Csányi, University of Hamburg, Germany
M. Bichler, Walter Schottky Institute, TU Munich, Germany
Correspondent: Click to Email
One of the major challenges in the realization of molecular electronic hybrid systems that comprise molecules as functional units is the reproducible fabrication of the inorganic contact electrodes. We have developed a novel technique to prepare such nanogap electrodes in a very precise manner, based on cleaved GaAs/AlGaAs semiconductor heterostructures grown by Molecular Beam Epitaxy (MBE).@footnote 1@ These electrodes of predetermined distance are macroscopically flat, coplanar and exceedingly clean. We report on electronic transport measurements on @pi@-conjugated, dithiolated Oligo-(phenylenvinylene) (OPV) derivatives of length 8.5 nm bridging a ~7 nm nanogap device. Starting from a high impedance behaviour before molecule deposition the OPV functionalized hybrid system develops a pronounced non-linear I-V characteristic measured at T=4.2 K. We compare our observations to model calculations on a simplified structure involving extended Hueckel theory and non-equilibrium Greens Function methods, and find qualitatively good agreement. @FootnoteText@ @footnote 1@ S.M. Luber et al., Nanotechnology 16, 1182 (2005).