The study of interfacial thermal resistance has always been a focal point in phonon transport research. Phonon transport across interfaces bridges the phonon properties in the materials on both sides of the interface. Therefore, the behavior of phonons at the interface cannot be simply described by superimposing the phonon properties of the two bulk materials. Instead, there exist special strong local modes at the interface that connect the phonon properties of the two bulk materials. Additionally, considering the often significant differences in the intrinsic properties of phonons on both sides of the interface, an indispensable part of interfacial thermal resistance research is the investigation of phonon anharmonic scattering processes. Understanding how vibrational modes are constructed at the interface, how phonons scatter at the interface, the correlation between the scattering process and the intrinsic properties of phonons in the two materials, and how the scattering behavior of phonons varies under different temperatures, stresses, and defects are all currently unresolved questions. Research on interfacial phonons can help us better understand, control, and design interfacial thermal resistance, thus expanding its potential applications.
