Semiconductors are an extremely diverse class of materials critical to enabling a variety of functional energy applications, from electricity generation and power conversion to efficient lighting and computing. The material properties needed in these applications are mediated by quantum processes that are affected by — and sometimes require — the interactions between electrons and lattice vibrations (phonons). Therefore, advances in our understanding of fundamental material behavior at the atomic level will accelerate the discovery and engineering of modern and next-generation materials and devices. Our improved capabilities for microscopic study coincide with the increased availability of significant computing power and open-source first-principles electronic structure codes. These codes, which implement density functional theory and density functional perturbation theory to calculate electronic and phononic properties at the quantum mechanical level, are run on supercomputers and allow us to study a diverse array of quantum processes.
In this talk, I will provide an overview of three studies that demonstrate the breadth and capability of computational methods to accurately capture both direct and phonon-assisted quantum processes: namely optical absorption, phonon-limited carrier mobility, and Auger-Meitner recombination. Our methods are particularly beneficial to investigate material systems where experimental measurement is challenging or quality samples are rare or do not yet exist. Ultimately, these techniques both accelerate the materials design process and inform our understanding of fundamental material behavior at the atomic level.