Eur. Phys. J. D 59, 375-378 (2010)
https://doi.org/10.1140/epjd/e2010-00196-2

Effects of contact atomic structure on the electron transport of pyridine-substituted dithienylethene optical molecular switch

¹ School of Science, Xian Polytechnic University, Xian, 710048, P.R. China
² School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P.R. China

Corresponding author: ^a xiacaijuan@xpu.edu.cn

Received: 22 December 2009
Revised: 17 May 2010
Published online: 27 July 2010

Abstract

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the effects of contact atomic structure on the electron transport of pyridine-substituted dithienylethene optical molecules with open- and closed-ring forms. The motivation for this study is the variable situations that may arise in break junction experiments. Three kinds of molecule-metal interface conformations including the hollow, bridge and top sites are studied. Theoretical results show that the conductance of the closed-ring is always larger than that of open-ring for all three connecting sites. When the molecule is located at the hollow site, this will lead to negative differential resistance under applied bias, while it cannot be found in the bridge and top sites.