Lattice-dynamics-based descriptors for interfacial heat transfer across two-dimensional carbon-based nanostructures

SM Hatam-Lee and K Gordiz and A Rajabpour, JOURNAL OF APPLIED PHYSICS, 130, 135106 (2021).

DOI: 10.1063/5.0055708

Graphene and several other two-dimensional (2D) carbon-based structures, including C3N, C3B, C2N, C3N4 (s-triazine), and C3N4 (tri-triazine), have attracted considerable attention due to their excellent thermal, mechanical, and electrical properties. In this study, the correlations between the interfacial thermal conductance (ITC) across these 2D nanostructures and the lattice-dynamical properties of the system, including (i) the phonon density of state (DOS) overlap between the sides of the interface and (ii) the percentage of different classes of vibrational modes for each heterostructure, are investigated. The results show that the percentage of localized interfacial modes is a strong descriptor for predicting ITC-even more effective than the widely accepted phonon DOS overlap. Moreover, the ITC between all combinations of these six carbon-based materials, its dependence on the length of the heterostructure, and the thermal rectification effect present in each interface structure is studied using non-equilibrium molecular dynamics simulations. The results show that the maximum and minimum ITC for infinite length systems belong to graphene/C3N and C2N/C3N4 (tri- triazine) heterostructures with values of 35.81 and 2.21 GWm(-2)K(-1), respectively. Comparing the thermal resistances at the interface and in the bulk of these heterostructures show that thermal transport in carbon-based 2D materials is influenced by the thermal resistance across their interfaces. These results not only contribute to our fundamental understanding of interfacial heat transfer, but can also serve as the basis for the design of nanoelectronic devices based on 2D materials, where the device level performance will indeed be influenced by interfacial phenomena. Published under an exclusive license by AIP Publishing.

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