Electronic structures and lattice dynamics of energy materials

Abstract

Emerging energy materials are attracting increasing research interest due to their various potential applications such as thermoelectrics and photovoltaics. The electrical, optical and thermal properties of materials are closely related to their electronic structures and lattice dynamics. Indepth understanding of materials in the electronic and atomistic scales is critical for effective engineering of their properties. In this presentation, I will speak about the detailed valence band features of SnS thermoelectrics and the doping effects of n-type impurities on the electrical transport properties. The electronic structure of another IV-VI compound GeSe and its evolution under high pressures will also be discussed. In a different topic, the lattice dynamics of hybrid perovskite MAPbI3 will be discussed based on the results obtained from molecular dynamics simulations and inelastic neutron scattering measurements. Using the mode decomposition technique, we have obtained the lifetimes of the optical phonons that have very large linewidths. Lastly, the strain effects on the anharmonic lattice dynamics of graphene will be discussed for better understanding of its intrinsic mechanical strength.