Tunable thermal property in edge hydrogenated AA-stacked bilayer graphene nanoribbons

The effect of edge hydrogenation on the thermal conductivity of AA-stacked bilayer graphene nanoribbons (BGNs) is explored by using the reverse non-equilibrium molecular dynamics method (RNEMD). We study the thermal transport properties of AA-stacked zigzag BGNs (ZBGNs) with different edge hydrogenation degrees in the range of 200-600 K. The calculated results show that the interlayer van der Waals interaction has a big significant influence on the thermal conductivity of AA-stacked BGNs compared with monolayer graphene nanoribbons (GNRs) in the same simulation conditions. For AA-stacked ZBGNs with different edge hydrogenation degrees, thermal conductivities firstly increase with the temperature increasing, and then start to decrease when reaching certain maximum always reach maximum values at the temperature of 300 K. Furthermore, the thermal conductivities of the simulation models have certain variation when the heat flow direction changes. In the meantime, the thermal rectification phenomenon is most obvious when the length ratio of the edge hydrogenated GNRs versus pristine one is 1. It is interesting that the thermal rectification effect is apparently weaken at high temperatures owing to obvious reduction of phonon power spectrum overlap, which implies that edge hydrogenated AA-stacked BGNs have the potential in future BGNs-based thermal rectification device applications. (C) 2015 Elsevier B.V. All rights reserved.