Thermal transport modeling from first-principles
Keivan Esfarjani (Rutgers University)
Prager Medal Symposium in honor of George Weng: Micromechanics, Composites and Multifunctional Materials
Tue 2:40 - 4:00
MacMillan 117
Modeling thermal conductivity has recently become of importance due to the need of thermal management in optoelectronic and thermoelectric devices. Models based on the relaxation time approximation have free parameters that are usually fitted to available experimental results. We have proposed a methodology to compute phonon relaxation times from a lattice dynamics Hamiltonian the parameters of which are derived from first-principles density functional theory calculations. Our results for the thermal conductivity of several bulk crystalline materials agree well with experimental data without using any fitting parameters. This approach gives access to the relaxation time of all the phonon modes, and provides the necessary ingredients for achieving an understanding of heat transport in crystals. In particular, we provide an explanation for the low thermal conductivity of IV-VI chalcogenides in comparison with III-V materials.