Nanoswitch-based on ring-opening of 1,3-cyclohexadiene molecule

In the framework of the density functional theory, in combination with the method of non-equilibrium Green functions (DFT+NEGF), electric transport characteristics of nanoswitch-based on ring opening of the 1,3-cyclohexadiene molecule (1,3-CHD) are modelled and analyzed. The main electrotransport characteristics (density of states, transmission spectrum, current-voltage characteristics (CVC), dI/dV-characteristics) of a nanoswitch, consisting of Au(111) electrodes forming a nanogap of ~ 10.37 Å, where a 1,3-CHD molecule is placed, upon external exposure of which its rings are opened and turns into a molecule of 1,3,5-hexatriene (1,3,5-HT). The opening of CHD molecule ring noticeably changes the transmission spectrum of the nanodevice: a new peak appears at an energy of 4.4 eV and the width of this peak increases with increasing distance between the ends of the opening σ-bound atoms. An analysis of the transmission spectrum, CVC and dI/dV-characteristics revealed that the 1,3-CHD molecule weakly transmits electric current in the nanosystems under consideration than the 1,3,5-HT molecule. With increasing distance between the final CHD atoms, the slope of the CVC of nanodevices increases, which indicates a decrease in the electrical resistance of the molecule after ring opening. The considered nanoswitch can be used as building blocks for creating logical gates in computer technology.