Transport in materials – understanding the motion of electrons, atoms, and phonons

Abstract

Transport phenomena are at the heart of many energy conversion processes. To describe and understand transport is thus crucial for the development of a variety of functional materials. One example is thermoelectric materials, where prediction of properties without any adjustable parameters is starting to get within reach. Knowledge about the electronic structure can give access to essential transport properties with predictive power, and many results may be compared directly to experiments at realistic conditions. A remaining challenge is to describe scattering of electrons and phonons in a realistic and quantitatively satisfactory manner. We describe efforts to meet this challenge for electron and phonon transport in promising thermoelectric materials. Transport of atoms in materials is a related challenge, and we present a study on Pd-based membranes for hydrogen production and separation. Understanding how adsorbates and alloying elements interact and segregate has led to prediction of novel ternary alloys for enhanced membrane materials.