Multi-functional switch effect in interlocking molecular rotators-on-graphene systems using electric fields

Abstract

One approach to design electronic devices is to use molecules whose configuration can be actively modified to control their electrical conductivity. A recent theoretical study provides a candidate in the form of interlocking rotating 1,2,3,4,5,6-benzenehexacarbonitrile molecules attached to a zigzag graphene nanoribbon (ZGNR). By applying an external electric field parallel to the graphene nanoribbon supporting such gear-like molecules, we herein computationally demonstrate that the conductivity of this system can be modified by modifying the electric field strength and molecular orientation. We achieve a ratio of up to 171% between maximum and minimum conductivity by changing the bias voltage (thus forming a conductance switch) and up to 158% by rotating the gears (forming a rotational switch). We also show that the rotational energy barriers of the gears can be significantly modified by changing the electric field strength. These results can help the design of future molecular machines by using carbon-based materials and assembling nanoscale components into molecular motors, molecular memory components, nanocars, nanorobots, etc.