| In recent years,two-dimensional(2D)heterostructures have shown great application potential in the fields of thermal management and micro-nano manufacturing because of their excellent thermal transport properties.However,when heterostructures are applied to nanodevices,various interface structures that have an important influence on the thermal transport performance of the device are inevitably produced.Therefore,the thermal transport performance of the interface determines the reliability and stability of the micro-nano device.To meet the design requirements of high-power electronic devices in the future,by using the molecular dynamics(MD)methods,this paper has conducted a systematic study on the interfacial thermal transport properties and the corresponding control methods of the typical materials i.e.,in-plane graphene/hexagonal boron nitride(Gr/h-BN)heterostructures.The research results are summarized as follows:1.In this paper,five different interface models of in-plane Gr/h-BN heterostructures are constructed,and the relationship between the interfacial thermal conductance(ITC)is systematically studied.The MD calculation results show that the order of magnitude of the five different interface models’ ITC is as follows: C–N > C–NB > C–NBA > C–BN > C–B.The average stress distribution analysis shows that the low/high interface stress distribution intensifies/constrains the vibrations of atoms near the interface,thereby facilitating/obstructing the transfer of heat flux across the heterostructures’ interface,resulting in a high/low ITC.2.In this paper,the multilayer in-plane Gr/h-BN heterostructures(MIGHHs)are constructed for the first time and the effects of the number of layers on the ITC are systematically studied.The computational results show that the ITC of the MIGHHs decrease with increasing layer number n and reaches convergence at n = 3.Surprisingly,the ITC convergence value is still greater than the ITC of the monolayer in-plane Gr/h-BN heterostructure,which indicates that the MIGHH is more conducive to interfacial thermal transport.The underlying physical mechanisms of phonon transport in heterostructures are probed through the stress concentration factor,overlap of phonon vibrational spectra and phonon participation ratio.In particular,by changing the stacking angle of MIGHH,a higher ITC can be obtained because of the thermal rectification behavior.The findings of this paper here are of significance for understanding the interfacial thermal transport behaviors of MIGHH,and are expected to attract extensive interest in exploring its new physical properties and industrial applications.3.In this paper,three different 2D material monolayers are used as substrates for inplane Gr/h-BN heterostructures,and the ITC is regulated by adjusting the interlayer interaction strength χ.The results show that when the monolayer Gr/h-BN in-plane heterostructure is coupled with Gr and h-BN substrates,ITC value gradually increases as the coupling strength increases.Among the three coupling structures,the Gr coupling structure is the most effective for improving the ITC.The analysis of atomic interaction density shows that the increase of atomic interaction density directly leads to the increase of in-plane heterostructures’ ITC.The spectral decomposition thermal conductance analysis proves that the 2D material substrate mainly affects the high-frequency region of the phonon and the contribution of the in-plane spectral thermal conductance to the total thermal conductance dominates.The results of the study show that coupling 2D materials substrates in in-plane heterostructures is an effective means to regulate the interfacial thermal conductance. |
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