Effect of Metallic Electrodes Ensemble on Charge Transport Characteristics of Cytosine Based Molecular Devices

Abstract

The charge transport through molecular devices using an ensemble of metal electrodes having nucleobase cytosine as the central molecule has been envisaged using a combination of semi-empirical Extended Huckel Theory and Non Equilibrium Green Function (NEGF). FFT-2D computational approach has been effectively applied to elucidate the electron transport characteristics of these molecular devices under both equilibrium as well as non-equilibrium states. The charge transport parameters viz. Device Density of States, Transmission Spectrum, I–V curve, G–V curve and HOMO-LUMO Gap are measured to exhibit the charge transport properties. By comparing the obtained quantum transport properties, we observe that silver remains the best choice among the three electrode materials under study as the molecular device with the silver electrodes exhibits the lower HOMO-LUMO Gap with increased current and conductance for the higher bias voltages in contrast to the other two configurations which show comparatively higher value of HOMO-LUMO Gap. Hence, the molecular device with the silver electrodes has greater possibility of getting utilized as a switch in DNA based nano-electronics applications.