Voltage controlled switches with ultrahigh GOn/GOff ratio on single layer graphene

A method for realizing voltage-controlled conductance switching using single layer graphene is proposed and numerically studied and presented. The ultrahigh conductance On/Off ratio (G_On/G_Off) is achieved through the "closing/opening" of an energy bandgap in single layer graphene. The G_On/G_Off reaches as high as ∼152 when the bandgap is of only ∼12 meV (B = 3) for the simulated device configuration. Furthermore, the G_On/G_Off ratio increases parabolically with the increasing of the product of U and d (i.e. U∗d) and increases exponentially with the increasing of the product of B and b (i.e. B∗b). In addition, the G_On/G_Off ratio increases with the increasing of the unit cell number N of the device. These features of merit provide ways for the optimization of the performance and properties of the switch.