Baoan Bian

Effects of different electrodes and substituent groups on molecular switching

We investigate the electronic transport properties of hydroxychalcone and flavanone molecules sandwiched between zigzag-edge or armchair-edge graphene electrodes using density functional theory and non-equilibrium Green’s function. The substitutions of electron-donating –NH2 and electron-withdrawing group –NO2 with armchair-edge graphene electrodes enhance the switching performance, which are analyzed by the transmission spectra, molecular projected self-consistent Hamiltonian and transmission eigenstates. It is found that the negative differential resistance effect observed in the device results from molecule–electrodes coupling with increased bias. The results suggest that different electrodes and substituent groups can influence the currents and switching ratios, indicating a potential application in future molecular circuits.