Thermal transport of isotopic-superlattice graphene nanoribbons with zigzag edge

Abstract

Thermal transport properties of isotopic-superlattice graphene nanoribbons with zigzag edge (IS-ZGNRs) are investigated. We find that by isotopic superlattice modulation the thermal conductivity of a graphene nanoribbon can be reduced significantly. The thermal transport property of the IS-ZGNRs strongly depends on the superlattice period length and the isotopic mass. As the superlattice period length decreases, the thermal conductivity undergoes a transition from decreasing to increasing. This unique phenomenon is explained by analyzing the phonon transmission coefficient. While the effect of isotopic mass on the conductivity is monotone. Larger mass difference induces smaller thermal conductivity. In addition, the influence of the geometry size is also discussed. The results indicate that isotopic superlattice modulation offers an available way for improving the thermoelectric performance of graphene nanoribbons.