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TT: Tiefe Temperaturen
TT 33: Transport - Nanoelectronics III: Molecular Electronics
TT 33.4: Talk
Tuesday, March 8, 2005, 14:45–15:00, TU H3027
Characterization of nanoscale molecular junctions — •Artur Erbe1, Anat de Picciotto2, Jennifer E. Klare2, Colin Nuckolls2, Kirk Baldwin3, and Robert Willett3 — 1Universität Konstanz, FB Phyisk — 2Columbia University, NY, USA — 3Lucent Technologies, Bell Labs, NJ, USA
Exploring the electronic possibilities of nanoscale organic materials has become an important challenge as modern lithographical techniques approach ultimate limits. In this regime, the properties of single or a few molecules will dominate the behavior of whole devices. Recent experiments on nanoscale molecular junctions show a large variety of results. Differences in the properties of the molecules themselves cannot fully account for these variations. This fact indicates that contact properties play an important role in the behavior of the whole junction. We present electrical measurements of various types of molecules using an electrical break junction technique. The formation of the junctions relies on electromigration in a narrow gold wire. This technique allows us to test the junctions under varying external conditions. Distinct features are found in the I-V-characteristics at low temperatures indicating that single or a few molecules are contacted. Some of those features can be affected by changes in applied gate voltage. The energy scales associated with these features cannot be explained with molecular properties alone. In order to explain our results we take interactions between the molecules and the contacting metals into account.