F. N. Ajeel*, L. F. AL-Badry and S. A.A. AL-Saidi Pages 53 - 59 ( 7 )
Background: The nanoscale junction represents one of the most active classes of materials, and they have been widely used as active materials for nanoelectronic applications.Objective: In this study, we theoretically analyzed the transfer characteristics for a single molecule in nanoscale junctions at room temperature. Method: All the calculations are based on Anderson model with electron-phonon interactions. The molecule transfer in the junction is viewed as a potential barrier crossing problem which is described by a truncated harmonic oscillator and the inelastic electron tunneling. Results: The transfer was done by overcoming the associated potential barrier due to a gain in energy from the tunneling electrons. The transfer behavior of the molecule between tow leads became more clearly visible by studying the transfer rate characteristics, which led to the numerical calculations. Characteristic features of this study include a power-law dependence of the transfer rate with the applied bias voltage and crossover from current-driven to thermally activated transfer by decreasing the vibrational mode energy or increasing the temperature of the junctions. Conclusion: Our analysis may present insight to understand the physical and chemical mechanisms of motion and reaction of single molecule induced by inelastic tunneling electrons.
Nanoscale junction, single molecule, NEGF model, vibrational heating mechanism, transfer rate, inelastic electron tunneling.
Department of Physics, College of Science, Thi Qar University, Nassiriya 64000, Department of Physics, College of Science, Thi Qar University, Nassiriya 64000, Department of Physics, College of Science, Thi Qar University, Nassiriya 64000