(531f) Detecting Molecular Motion On Graphene: An Opto-Electromechanical Logic Device

A major challenge of molecular electromechanics is to incorporate single molecules as electronic components within circuits. In this talk, we demonstrate that Graphene presents an ultra-sensitive electrical platform which can overcome this challenge by electrically detecting the sub-nano scale mechanical motion, occurring within a single azo-benzene molecule, tethered onto its surface. The planar open ended sp² bond carbon lattice structure in graphene confines the dense π carriers, providing them highest mobilities and facilitating an ultra-sensitive platform amenable to detect nanoscale motions. We present a working design of an azo-molecule functionalized graphene construct and study the quasi­ quantum sensitivity of Graphene surface by a detailed investigation of the fermionic redistribution it exhibits in response to the light-induced molecular motion in azo-molecule. This enables the azo-molecule to act an active electronic component within the nano-electrical construct. This graphene based opto-electro-mechanical device is characterized in detail for its ‘electrical response’ (conductivity, carrier density and mobility states) in the optically induced cis and trans conformations of tethered azo molecules, factors which can regulate this response, and the mechanism of the conformation-induced electronic modulation. The results presented here will enable development of next-generation graphene based systems such as optoelectronic-switches, nano-mechanical motors and logic devices.