Stimulated by recent experiments for diblock molecular junctions, we investigated a possible mechanism to explain the giant diode property by focusing on the electron correlation effect. Based on our observation that the first-principles generalized gradient approximation (GGA) fails to account for the large rectification behavior at high voltage, we have made nonequilibrium many-body calculations using the extended Hubbard model. Theoretical calculations including the electron correlation effect within the self-consistent GW approximation using Keldysh Green's functions give a large enhancement of the diode property over the mean-field result. We suggest that the many-body electron collision effect confined in one of the diblocks is necessary to explain the large rectification behavior found in experiments.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 22 2011|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics