SUMMARY

Thermophysical properties of materials are often key parameters in the determination of the thermal response, performance, and reliability of many engineering devices. As such, it is highly desirable to control or tailor the thermal properties of materials for specific applications. In contrast to the technological revolution in modifying the electrical transport properties, our understanding and methods to manipulate the thermal conductivity of solid state materials is very limited. The theoretical basis of structure-thermal property relationships in solid state materials has be described through the Boltzmann transport equation for the past 80 years. However, the current application of the theory relies on many simplifying assumptions in order to obtain tractable descriptions of thermal transport. The objective of this work is to improve upon current thermal conductivity modeling paradigms. This will yield a more accurate understanding of phonon physics and allow an extension of current models to complex and exotic materials. Thermal conductivity models are generalized for use with complex crystals and phonons in nanostructures are studied.