Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, 22904, USA.
Intel Corporation, Logic Technology Development, 5200 NE Elam Young Parkway, Hillsboro, OR, 97124, USA.
Adv Mater. 2018 Nov;30(44):e1804097. doi: 10.1002/adma.201804097. Epub 2018 Sep 17.
The role of interfacial nonidealities and disorder on thermal transport across interfaces is traditionally assumed to add resistance to heat transfer, decreasing the thermal boundary conductance (TBC). However, recent computational studies have suggested that interfacial defects can enhance this thermal boundary conductance through the emergence of unique vibrational modes intrinsic to the material interface and defect atoms, a finding that contradicts traditional theory and conventional understanding. By manipulating the local heat flux of atomic vibrations that comprise these interfacial modes, in principle, the TBC can be increased. In this work, experimental evidence is provided that interfacial defects can enhance the TBC across interfaces through the emergence of unique high-frequency vibrational modes that arise from atomic mass defects at the interface with relatively small masses. Ultrahigh TBC is demonstrated at amorphous SiOC:H/SiC:H interfaces, approaching 1 GW m K and are further increased through the introduction of nitrogen defects. The fact that disordered interfaces can exhibit such high conductances, which can be further increased with additional defects, offers a unique direction to manipulate heat transfer across materials with high densities of interfaces by controlling and enhancing interfacial thermal transport.
界面非理想性和无序性对界面热传递的作用传统上被认为会增加传热阻力，降低热边界电导（TBC）。然而，最近的计算研究表明，界面缺陷可以通过材料界面和缺陷原子固有的独特振动模式的出现来增强这种热边界电导，这一发现与传统理论和传统理解相矛盾。通过操纵构成这些界面模式的原子振动的局部热通量，原则上可以增加 TBC。在这项工作中，提供了实验证据表明，界面缺陷可以通过界面处相对较小质量的原子质量缺陷产生的独特高频振动模式的出现来增强 TBC。在非晶 SiOC:H/SiC:H 界面上，TBC 达到了 1 GW m K 左右，并通过引入氮缺陷进一步提高。无序界面可以表现出如此高的电导率，并且可以通过增加额外的缺陷进一步提高，这为通过控制和增强界面热传递来操纵具有高密度界面的材料的热传递提供了一个独特的方向。
