Thermal transport across graphene/GaN and MoS2/GaN interfaces

Abstract

Graphene/GaN and MoS2/GaN have important applications in optoelectronic devices. The two-dimensional (2D) materials greatly improves the device performance due to its overwhelming advantages. 2D materials introduce multiple interfaces while improving device performance. With the miniaturization of devices, the interfacial thermal transport has crucial effect on the performance and lifetime of optoelectronic devices. The interfacial thermal conductance of Al/graphene/GaN and Al/MoS2/GaN are measured by the time-domain thermoreflectance (TDTR) technique from 100 K to 400 K. The density of states and spectral thermal conductance are calculated based on nonequilibrium molecular dynamics (NEMD) simulations to understand the underlying thermal transport mechanism. The overlap energy is used to understand the thermal transport efficiency. Most interesting, the results are opposite to that measured by TDTR. Moreover, the spectral thermal conductance and phonon dispersion are used to understand the thermal transport mechanism in frequency domain. The results provide experimental and theoretical guidance for thermal management of optoelectronic devices.