Predictive calculations of phonon-assisted quantum processes

Quantum processes mediated by phonons play an important role in the characterization of materials and in the operation of electronic and optoelectronic devices. I will discuss the theory and recent results in the predictive modeling of phonon-mediated quantum processes in materials with atomistic calculations based on density functional and many-body perturbation theory. I will discuss the computational methodology and results for phonon-assisted optical absorption in metals and in indirect-gap semiconductors such as silicon (Si), boron arsenide (BAs), and boron nitride (BN). I will also discuss calculations for phonon-assisted Auger recombination in wide-band-gap semiconductors, an important nonradiative mechanism that dominates carrier recombination at high free-carrier concentrations. The results shed light into the interaction of light with materials and the efficiency of light emitters. This work was performed in collaboration with Kyle Bushick, Kelsey Mengle, Guangsha Shi, Andrew McAllister, Dylan Bayerl, and Chris Van de Walle.