Electronic and transport properties of a molecular junction with asymmetric contacts.
Asymmetric molecular junctions have been shown experimentally to exhibit a dual-conductance transport property with a pulse-like current-voltage characteristic, by Reed and co-workers. Using a recently developed first-principles integrated piecewise thermal equilibrium current calculation method and a gold-benzene-1-olate-4-thiolate-gold model molecular junction, this unusual transport property has been reproduced. Analysis of the electrostatics and the electronic structure reveals that the high-current state results from subtle bias induced charge transfer at the electrode-molecule contacts that raises molecular orbital energies and enhances the current-contributing molecular density of states and the probabilities of resonance tunneling of conduction electrons from one electrode to another.
Tsai
M-H
MH
Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan. tsaimh@mail.nsysu.edu.tw
Lu
T-H
TH