Abstract
We calculate current rectification by molecules containing a conjugated molecular group sandwiched between two saturated (insulating) molecular groups of different lengths (molecular quantum dot) using an ab initio nonequilibrium Green’s function method. In particular, we study with naphthalene as the conjugated central group. The rectification current ratio has been observed at and due to resonant tunneling through the molecular orbital (MO) closest to the electrode Fermi level (lowest unoccupied MO in the present case). The rectification is limited by the interference of other conducting orbitals, but can be improved by, e.g., adding an electron withdrawing group to the naphthalene.
- Received 12 April 2003
DOI:https://doi.org/10.1103/PhysRevB.68.235305
©2003 American Physical Society