Interfacial Defect Vibrations Enhance Thermal Transport in Amorphous Multilayers with Ultrahigh Thermal Boundary Conductance

다국어 초록 (Multilingual Abstract)

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−2 K−1 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.
A new regime of heat transfer in amorphous nanolaminates and disordered solids in general is reported, in which interfacial modes introduced through defects in the vicinity of the interface between two amorphous solids lead to ultrahigh thermal conductance across these disordered interfaces. This work demonstrates the significance of interfacial modes on heat transfer in nanolaminates with high density of interfaces.