First-principles study of the switching characteristics of the phenoxynaphthacenequinone-based optical molecular switch with carbon nanotube electrodes

We have studied the switching characteristics of an optical molecular switch based on the phenoxynaphthacenequinone (PNQN) molecule with two armchair single-walled carbon nanotube (SWCNT) electrodes using the first-principles density functional-based non-equilibrium Green's function (DFT-NEGF) method. It is shown that a maximum on–off ratio (about 120) can be obtained at 0.9 V. Our result shows that the PNQN molecule is one of the good candidates for optical molecular switches and the SWCNTs are promising electrode materials and will be useful in the near future.