Reduction of interfacial thermal transport of bilayer in-plane graphene/hexagonal boron nitride heterostructures via interlayer sp3 bonds, defects and stacking angle

Most studies on graphene/h-BN heterostructures are confined to in-plane structures or single vertical without paying attention to their combination, which may lead to many interesting physical properties. Two configurations of bilayer in-plane graphene/h-BN heterostructures (multiple-mixed heterostructures) were constructed. On the basis, van der Waals structure gradually changes to quasi-three-dimensional configuration by introduction of interlayer sp(3) bond. The coupling effect of defects, interlayer sp(3) bonds and interface connection on the interfacial thermal conductance (ITC) of multiple-mixed heterostructures was studied. The results show that the ITC values of multiple-mixed heterostructures depends more on the type of covalent bond between interfaces than on the weak van der Waals force. In considering the stacking angle, the spatial configuration of bilayer staggered stacked heterostructures (BSSH) is more conducive to ITC than bilayer parallel vertically-stacked heterostructures (BPSH). In considering the interface connection and the direction of heat flow, the ITC of multiple-mixed heterostructures do follow similar trend, comparing the single-layer Gr/h-BN heterostructure. In addition, the interlayer sp(3) bonds play the part of defects, and the defects and interlayer bonds will form a defect amplification effect. More specially, the interlayer bonds affect the ITC of BSSH in two contrary ways. The idea of using interlayer bonds, defect and stacking angle (coupling effect) in bi-layer heterostructure contributes to precisely tunable ITC of similar two-dimensional materials in designing nanoscale devices.

Automated summary

Most studies on graphene/h-BN heterostructures focus on in-plane or single vertical structures, neglecting the interesting properties of combination. The interfacial thermal conductance of multiple-mixed heterostructures strongly depends on the type of covalent bond between interfaces rather than weak van der Waals force. The use of interlayer bonds, defects, and stacking angle in bi-layer heterostructures contributes to precisely tunable interfacial thermal conductance, aiding in the design of nanoscale devices.