Tuning phonon properties in thermoelectric materials.

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This review article presents a discussion of theoretical progress made over the past several decades towards our understanding of thermoelectric properties of materials. Particular emphasis is placed upon describing recent progress in 'tuning' phonon properties of nanocomposite materials for gaining enhancement of the thermoelectric figure of merit.I would like to thank my postgraduate students, postdoctoral fellows and research collaborators who have helped me develop the ideas presented in this article. In particular, I would like to thank Ceyda Yelgel for her contribution in the initial development of the TE project, and Steven Hepplestone and Iorwerth Thomas for their contribution in the development of phonon-interface and anharmonic interactions in superlattice structures presented in this review article. I also thank Steve and Iorwerth for a careful reading of this manuscript and making suggestions for improvement of the material presented. Finally, I express my sincere thanks to the EPSRC (UK) for their support of our research on phonon engineering of nanocomposite thermoelectric materials through the grant number EP/H046690