Electronic transport behavior of 1-(Phenyldiazenyl) naphthalen-2-ol and its derivatives as optical molecular switches: A first-principles approach

We studied the electronic transportation properties of 1-(Phenyldiazenyl)naphthalen-2-ol and its derivatives, as optical molecular switches, by using the nonequilibrium Green?s function (NEGF) formalism combined with the first-principles density functional theory (DFT). To describe this switching, we applied the geometrical and topological parameters, Time-dependent density functional theory (TD-DFT), and the second-order interaction energies, E(2), results. The mentioned switching for titled molecules occurred between their tautomers, hydrazo and azo forms, upon photoexcitation. According to our results the current rate of titled molecules is more than that the other reported molecules, about 40,000 nA. Therefore, titled molecules show appropriate potential for using in molecular switch tools. The transmittance spectra and I?V curves show the current of the azo tautomer is more than that in the hydrazo tautomer. This result agree with increasing of the intramolecular hydrogen bond strength, electron densities of aromatic and chelated rings, and the hyperconjugations in the azo forms. In addition, the -OCH3 and -NO2 groups, does not remarkably affected the current rate with Y (111) (Y =Au, Ag, and Pt) electrodes. The best performance obtained in Ag electrode, in while in the other reported molecular switchers Au electrode was appropriated.