Molecular Diode at Fast Switching on (off) Regime

Abstract

It is shown that after a sudden change of the voltage bias in device ''electrodemolecule-electrode'', only the hopping current components are able to achieve a great value as compared to the steady current. The effect becomes especially noticeable at asymmetric coupling of the molecule to each electrode. At such asymmetry, the molecule exhibits itself as a molecular diode which is kinetically recharged during the transfer of electrons through a molecule. Just a specific kinetic molecular charging (at switching on the voltage) and discharging (at switching off the voltage) become responsible for a formation of switch-on and switch-off currents.

Transient switch-on/off currents in molecular junctions

“…Note that a similar effect exists even if the charge transmission occurs with the participation of the frontier orbital only. 28,29 In this way the appearance of large transient switch-on/off currents in the molecular junctions with nonidentical couplings of the molecule to the electrodes can be realized. The effect becomes more pronounced for molecules with sustainable localized molecular orbitals.…”

“…The objective of the present study is to examine the formation of transient switch-on and switch-off currents in a molecular junction where electron transmission through the molecule covers more than a single molecular orbital. This allows one not only to generalize the results obtained in the framework of the simplest model with only a single frontier MO, 28,29 but aids to understand the physics of such transient processes for physically more realistic L-M-R systems.…”