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TT: Fachverband Tiefe Temperaturen

TT 21: TR: Nanoelectronics III - Molecular Electronics 2

TT 21.4: Talk

Tuesday, March 15, 2011, 11:15–11:30, HSZ 301

Electron transport through π-conjugated molecules anchored via carboxilate groups to Cu(110) electrodes — •Shigeru Tsukamoto, Vasile Caciuc, Nicolae Atodiresei, and Stefan Blügel — Peter Grünberg Institut & Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany

Nowadays, carboxilate-Cu bonds[1] are recognized as an alternative to the thiolate-Au bonds to be used in future molecular electronic devices. As a consequence, a clear understanding of the electron transport properties is highly desirable and, in particular, ab initio simulations are used to elucidate and design the functionality of specific molecules in a given organic-metal electrode environment.

Here we report on the transmission properties of three aromatic molecules anchored via carboxyliate groups to the Cu(110) electrodes. In our approach, the scattering wave functions are computed by solving the Lippmann-Schwinger equation.

While thiolate-Au systems show both sharp and broad transmissions peaks, the electron transmissions of the aromatic carboxilates-Cu molecular systems exhibit only sharp peaks. This implies that the molecular system with carboxilate-Cu bonds are more sensitive to change in bias voltage as compared to that with thiolate-Au ones. Furthermore, we demonstrate that the switching property of the molecules can be locally controlled by replacing a CH group of the aromatic ring with an N atom since the transmissions peaks are shifted to lower energies keeping the peak-peak distance.
M. C. Lennartz et al., Langmuir, 25, 856 (2009).