Enhancing the interfacial thermal conduction of the graphene sheets via chemical bond–bond connections

Abstract

Graphene, after its discovery in 2004, was known to possess extremely high thermal conductance. In the practical applications, however, the thermal conductance was unfortunately low compared with its theoretical value since the heat transfer among individual graphene sheets is largely hindered by the boundary phonon dissipation. In this first-principles study, we propose a new strategy to enhance the interfacial thermal transport, that is, chemical bond–bond connections. Organic, metal and metal-oxide groups are adopted to link two graphene nanoribbons, acting as a thermal bridge. In such models, the thermal conductance is significantly enhanced, as compared with the non-linked counterparts in which the van der Waals interactions dominate. In numbers, the highest thermal conductance of 0.577 GW·m–2·K–1 at 300K (which preserves as much as 13.2% compared with the pristine nanoribbon) can be obtained when linked by –Al– groups. The enhancement mechanism as regards different bond–bond connections is also discussed. Our study paves the way to exploring the enhancement of interfacial heat transfer. Even though the work was done based on the graphene models, it can be generally extended to a variety of inorganic and organic families.