Tuning cross-plane thermal conductivity of multilayer graphene/h-BN vdW heterostructures via composition distribution

作者：Youzhe Yang, Jun Ma, Jie Yang, Ning Wei, Yingyan Zhang · 发表于：International Journal of Heat and Mass Transfer · 年份：2024 · DOI：10.1016/j.ijheatmasstransfer.2024.125808 · 被引用次数：9 · 研究领域：Thermal properties of materials、Graphene research and applications、Thermal Expansion and Ionic Conductivity

• The innovative multilayer graphene/h-BN (GBN) vdW heterostructures with gradient composition distribution are designed to achieve low cross-plane TC. • The tunable TC of GBN heterostructure are achieved by various parameters. • The sensitivity of the cross-plane TC of GBN to in-plane and out-of-plane strains, bonding strength, layer number are revealed. • The fundamental mechanisms of the TC variation are explained through the analysis of PDOS. Nanomaterials with low thermal conductivity (TC) are ideal candidates as thermoelectric materials. In this direction, we design innovative multilayer graphene/h-BN (GBN) van der Waals (vdW) heterostructures with gradient composition distribution (C, B and N atoms), inspired by the newly synthesized boron carbonitride nanosheets. Three types of 26-layer GBN models are constructed and investigated, i.e. U-shape, X-shape, A-shape, representing uniform, symmetrical, and asymmetrical distributions of carbon atoms along the cross-plane direction, respectively. Based on non-equilibrium molecular dynamics (NEMD) simulation, we confirm that X-shape GBN model possess the lowest cross-plane TC, approximately 7 times smaller than that of the uniform U-shape graphene. The cross-plane TC can be further reduced by applying tensile strains or decreasing interlayer coupling strength. These findings elucidate the significant role the composition distribution plays in the thermal transport of GBN vdW heterostructures. However, the mechanical properties...