When light shines on materials, energetically-excited electrons interact with positive charges, holes. In many materials of interest, for instance for energy conversion and storage, strongly-bound electron-hole pairs called excitons are generated. Excitonic materials are widely used, for example in photovoltaics, catalysis, transport, and quantum information applications. The excited-state phenomena involved are strongly related to materials structure and composition, influencing the exciton spatial confinement and lifetime. These are reflected in non-radiative excitonic processes, such as multi-exciton generation, exciton diffusion, and exciton decay into long-lived dark states.
Our group develops and applies advanced ab initio many-body computational approaches to study non-radiative exciton phenomena in materials of complex structure. We wish to understand underlying interactions composing and evolving the excited states, with a strong emphasis on exciton-exciton interactions, exciton diffusion, exciton-phonon coupling and charge transfer at exciton traps, and their relation to materials structure and design.