Revealing the heat transport mechanism in typical heterostructures is crucial for designing GaN power chips with better engineering heat transfer performance. Herein, the effect of nanoscale nonplanar feature structures (NNFSs) on the interfacial thermal resistances (ITRs) of w-AlN/bilayer graphene/3C-SiC heterostructures is investigated systematically by molecular dynamics. The results indicate that the increase of the NNFSs numbers contributes to the decrease of the ITRs when the height is lower than the cutoff distance of the interaction. Multiple analyses indicate that, although the interactions at two van der Waals sub-interfaces (w-AlN/graphene and graphene/graphene) slightly weaken the phonon transfer, the increase of the NNFSs numbers enlarge the overlaps of phonon density of state (PDOS), which provides more phonon transfer channels. However, when the height is higher than the cutoff distance, the ITRs increase significantly due to the double decrease of the interactions and the overlaps of PDOS for the w-AlN/graphene sub-interface. These phenomena are further verified by the transient transport of energy. Besides, the NNFSs with random distribution also contribute to the reduction of the ITRs. We believe that the results of this work will provide significant guidance for improving the thermal transport performance of GaN power chips.

中文翻译：

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通过纳米级非平面特征结构调节 w-AlN/石墨烯/3C-SiC 界面的界面热阻

揭示典型异质结构中的热传输机制对于设计具有更好工程传热性能的GaN功率芯片至关重要。在此，通过分子动力学系统地研究了纳米级非平面特征结构（NNFS）对w-AlN/双层石墨烯/3C-SiC异质结构的界面热阻（ITR）的影响。结果表明，当高度低于相互作用的截止距离时，NNFS 数量的增加有助于 ITR 的减少。多重分析表明，虽然两个范德华子界面（w-AlN/石墨烯和石墨烯/石墨烯）的相互作用略微削弱了声子传递，但NNFS数量的增加扩大了声子态密度（PDOS）的重叠，提供更多的声子传输通道。然而，当高度高于截止距离时，由于w-AlN/石墨烯子界面的相互作用和PDOS重叠的双重减少，ITR显着增加。这些现象通过能量的瞬态传输得到进一步验证。此外，随机分布的NNFS也有助于减少ITR。我们相信这项工作的结果将为提高GaN功率芯片的热传输性能提供重要指导。