The E–Z photo-isomerization switching behavior in single molecular device with carbon nanotube electrodes

By using nonequilibrium Green’s functions in combination with the density-functional theory, we investigate the electronic transport properties of the molecular device constructed by a single 4,4-(ethene-1,2-diyl) dibenzoic acid sandwiched between carbon nanotube electrodes. The results show that an obvious reversible switching behavior can be observed when the molecular structure changes between E isomerization and Z isomerization by ultraviolet irradiation or visible irradiation. More importantly, the switching ratio can reach to a maximum (about 7000) at 0.28 V and then decrease gradually to a minimum at 0.48 V. It is suggested that the controllable switching behavior is very useful for the design of functional molecular devices.