Quantitative CurrentVoltage Characteristics in Molecular Junctions from First Principles
Abstract
Using selfenergycorrected density functional theory (DFT) and a coherent scatteringstate approach, we explain currentvoltage (IV) measurements of four pyridineAu and amineAu linked molecular junctions with quantitative accuracy. Parameterfree manyelectron selfenergy corrections to DFT KohnSham eigenvalues are demonstrated to lead to excellent agreement with experiments at finite bias, improving upon orderofmagnitude errors in currents obtained with standard DFT approaches. We further propose an approximate route for prediction of quantitative IV characteristics for both symmetric and asymmetric molecular junctions based on linear response theory and knowledge of the Stark shifts of junction resonance energies. Our work demonstrates that a quantitative, computationally inexpensive description of coherent transport in molecular junctions is readily achievable, enabling new understanding and control of charge transport properties of molecularscale interfaces at large bias voltages.
 Publication:

Nano Letters
 Pub Date:
 December 2012
 DOI:
 10.1021/nl3033137
 arXiv:
 arXiv:1212.0019
 Bibcode:
 2012NanoL..12.6250D
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Materials Science;
 Physics  Computational Physics
 EPrint:
 6 pages, 3 figures