Thermal characteristics of graphene nanosheet with graphane domains of varying morphologies

Abstract

In this paper, thermal characteristics of graphene nanosheet embedded with graphane quantum dots (QDs) are investigated using Non-Equilibrium Molecular Dynamics (NEMD) method. Thermal conductivity of nanoribbon is demonstrated to be tunable by manipulating the geometrical characteristics of graphane QDs without changing the amount of hydrogenation. Graphane QDs of larger circumferences cause more deterioration in heat transfer due to the scattering of phonons occurred at the graphene-graphane interface. As a result, nanoribbon with graphane QDs possesses higher thermal conductivity than that with random hydrogenation of same amount. Under fixed circumferences, the length-to-width ratio of QD is revealed to be the most important causes of deterioration in thermal conductivity. Graphane QDs of high length-to-width ratio have smaller deterioration effect on thermal conductivity. Combing the effect of circumference and length-to-width ratio, the thermal difference between nanoribbons with graphane QDs of different shapes can be sufficiently interpreted. The demonstrated mechanism can be applied for the optimization of nanodevices fabricated from hydrogen functionalized graphene.