Effects of Ultrathin Interlayers on Thermal Boundary Conductance at Metal-Dielectric Interfaces

Heat transport in micro- and nano-scale materials have an increasingly important role in thermal management of numerous technologies such as thermoelectric energy conversion, microelectronics, and plasmonic devices. Understanding the heat transport contributions from the interface is crucial when interfacial resistance forms a significant fraction of the total thermal resistance of the device. In this thesis, we analyze the modification of thermal conductance at metal-dielectric interfaces by inserting few-nanometer thick metal interlayers. A thickness-dependent interlayer study suggests that interfacial conductance alters significantly at ultrathin thicknesses before reaching a plateau. Our results reveal that the electron-phonon coupling strength of an interlayer plays a significant role in determining the overall thermal boundary conductance. Analysing heat transport mechanisms across a variety of metal-dielectric interfaces by means of an interlayer indicated that thermal boundary conductance depends on an interplay between the phonon vibrational properties and metal electron-phonon coupling strength overlap.