Effect of hydrogenated graphene on interfacial thermal transport across gallium nitride/silicon carbide heterostructures

Abstract

Optimizing thermal interface materials plays a crucial role in enhancing the heat dissipation performance of microelectronic and nanoelectronic devices. In this work, non-equilibrium molecular dynamics (NEMD) simulations were employed to investigate the effect of hydrogenation modification of single-layer graphene on the interfacial thermal conductance (ITC) of gallium nitride/silicon carbide heterostructure. The findings demonstrate that the ITC of heterostructures exhibits a non-monotonic trend, initially increasing and then decreasing, with increasing hydrogenation concentration. The calculation of critical parameters such as phonon density of states, phonon participation ratio and phonon transmission function reveals that this phenomenon originates from the competition among multiple phonon transport mechanisms, including enhanced interfacial coupling on the SiC side, inelastic phonon scattering and phonon coherence. Subsequent research has demonstrated that the spatial distribution of hydrogenation configurations significantly influences ITC. At equivalent hydrogen coverage, the random hydrogenation mode results in an ITC increase of up to 34.2 % over the ordered mode. This effect is primarily attributed to the random distribution, which enhances phonon coupling between hydrogenated graphene and adjacent materials while mitigating detrimental interfacial interference. Additionally, the effect of ambient temperature on ITC has been systematically examined and quantified. This study elucidates the dominant mechanisms of phonons across different frequency bands in thermal transport at heterointerfaces and provides a theoretical basis for optimizing thermal interface materials via controllable hydrogenation.