Rectifying and conductance switch behaviors of molecular devices modulated by intramolecular hydrogen bonding

摘要

By applying nonequilibrium Green's function method in combination with density functional theory, we theoretically investigate the effect of intramolecular hydrogen bonding on transport properties of a new synthesized alpha-hydroxyphenyl pyridine molecular diode (Wang and Yu, 2011). Numerical results show that intramolecular hydrogen bonding presents obvious influence on rectifying behaviors of the diode, as the hydrogen bonding could rotate the adjacent aromatic rings into coplanar structure. Appropriate contact configurations between the molecule and electrodes are shown to be important for obtaining the experimental rectifying characteristics. Furthermore, bistable state configurations related to the intramolecular hydrogen bonding are obtained and conductance switch behavior is presented. Accordingly, a molecular conductance switch with high On-Off ratios is proposed. The analysis of molecular projected self-consistent Hamiltonian and the spatial distribution of frontier molecular orbitals as well as the transmission coefficients reveals the mechanism of these consequences. (C) 2015 Elsevier B.V. All rights reserved.