Computational study of band structure engineering and anharmonic lattice dynamics

Abstract

Emerging materials with novel properties attract increasing research interest due to their potential applications in various important fields of engineering. The electrical and thermal transport properties of materials may be optimized via the engineering of the electronic structures and lattice dynamics. In-depth understanding of materials in the electronic and atomistic levels is, therefore, of great significance. Despite the difficulties in experimental characterizations of detailed band dispersions and phonon spectra, computational study provides an alternative way for obtaining important understanding of material properties in a deep level. In this presentation, I will discuss about the electronic band structures of the IV-VI compounds, which have potential applications in thermoelectric and photovoltaic devices. The effects of dopants and external strains on the band structures will be thoroughly discussed. In a different topic, I will focus on the calculations of phonon lifetimes of materials using the mode decomposition technique in combination with molecular dynamics simulations and the perturbation theory. The manipulation of phonon scattering via external strain will also be discussed.