Speaker
Description
Carrier localization plays an important role in determining transport and optical properties of functional materials, particularly in soft and polar semiconductors relevant to optoelectronic and energy applications. However, modeling these localized states in realistic materials is not straightforward, because their formation is closely tied to local symmetry breaking, structural fluctuations, and defects. In this talk, I will discuss recent first-principles results on polarons and self-trapped excitons in halide perovskites and BiVO$_4$. I will show how atomistic electronic-structure calculations can be used to identify competing localized states, relate them to spectroscopic signatures, and assess how finite temperature affects their stability and dynamics. Finally, I will highlight recent progress in using machine-learning-based molecular dynamics to describe these phenomena over larger length and time scales.