OS5-2-2 First-principles heat conduction analysis of thermoelectric materials by anharmonic lattice dynamics and molecular dynamics

Abstract

Improving thermoelectric energy conversion requires high power factor and low lattice thermal conductivity. Although first-principles-based calculations for power factor have been carried out extensively, there are few studies on lattice thermal conductivity based on first-principles. In this work, to accurately evaluate heat conduction, we have performed the first-principles-based anharmonic lattice dynamics for single-crystalline lead-telluride and magnesium-silicide that are leading thermoelectric materials in intermediate-high temperature regions. Subsequently, we have performed the molecular dynamics using anharmonic potentials obtained by first-principles for lead-chalcogenides alloyed crystal. It is demonstrated that the systematic first-principles-based calculations deliver accurate lattice thermal conductivities of single-crystals as well as alloyed crystals.