Efficient Spectrally-Resolved Electron Transport for Thermal Property Prediction

In this work, we describe our progress and methods to simulate thermal electron transport in materials for the purposes of thermal property prediction. We harness the Boltzmann transport equation (BTE) in SAAF (self-adjoint angular flux) form, discretized in space by the finite element method and angle by the discrete ordinates method, using the MOOSE (Multiphysics Object Oriented Simulation Environment) framework to simulate thermal electron transport in real materials. These methods are consumers of ``cross-section'' data obtained from density functional theory calculations. We introduce Boltzmann, an open source carrier transport code built within the MOOSE framework, which will soon be publicly available. We demonstrate the effectiveness of our explicitly coupled (in temperature and Fermi energy) thermal electron transport method (in the absence of electric fields) for the prediction of thermal and electrical conductivity, thermal and electrical flux, and heat capacity in thin films of silicon.