Materials Research Lecture

An interface scatters phonons and thus poses resistance to the heat flow, in addition to the bulk resistance of the material. The associated interfacial thermal resistance can dominate the overall heat flow when the density of the interfaces is high, such as in nanoscale and interfacial materials. When two (or more) interfaces or junctions are at a distance smaller than the phonon mean path, the interfacial resistances of each interface are not independent. Using molecular dynamics simulations and phonon scattering based analysis we will study heat flow mechanisms across proximal interfaces in various systems including self-assembled organic monolayers between two solids, nanoscopic solid adlayer on a substrate and molecular junctions. We will demonstrate the presence and role of multiple phonon scattering and interference effects on individual phonons and overall interfacial thermal transport.