Computer Simulation of the Electrotransport Characteristics of the “Au – Bipyridine – Au” Nanocontact

Authors D. Sergeyev1,2

1Zhubanov Aktobe Regional University, 34, Moldagulova Ave., 030000 Aktobe, Kazakhstan

2Begeldinov Military Institute of Air Defense Forces, 39, Moldagulova Ave., 030012 Aktobe, Kazakhstan

Issue Volume 11, Year 2019, Number 4
Dates Received 31 May 2019; revised manuscript received 02 August 2019; published online 22 August 2019
Citation D. Sergeyev, J. Nano- Electron. Phys. 11 No 4, 04023 (2019)
PACS Number(s) 73.63. – b, 73.40. – c, 72.90. + y
Keywords Electron transport, Nanocontact (2) , Bipyridine, Negative differential resistance, Current-voltage characteristic (12) .

In the framework of the density functional theory, using the method of non-equilibrium Green's functions (DFT + NEGF) and in the local density approximation, the electrotransport characteristics of the “Au – Bipyridine – Au” nanocontact were studied. The calculation is implemented in the program Atomistix ToolKit with Virtual NanoLab. The current-voltage, dI/dV characteristics, the transmission spectrum and the density of states of the nanocontact are calculated. It is shown that the transmission spectra of the nanocontact are reminiscent of the spectrum of resonant tunnel structures. A shift in transmission spectra was detected when a bias voltage was applied, which is explained by a voltage drop along the molecular transition. It is shown that DDOS at negative energy (– 6 ÷ – 1 eV) is significantly higher than at positive energy. In the bias voltage range – 3 ÷ – 0.5 V, a noticeable current oscillation is observed. It is shown that a multitude of areas with negative differential resistance, possibly due to resonant tunneling of quasi-particles, appear on the current-voltage characteristic of the nanosystem. The same changes are observed on the dI/dV-characteristic. The results obtained may be useful for calculating new promising electronic devices of molecular electronics.

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