Understanding the energetics and dynamics of excited states formed by light-matter interactions is essential for applications across optoelectronics and photophysics. In systems of reduced dimensionality, strongly-bound particles named excitons serve as the main energy carriers, with long diffusion and relaxation lifetimes. As exciton dynamics are coupled to optical selection rules that stem from the atomic structure, enhanced exciton transport efficiency
can be achieved through local structural modifications, such as atomic impurities, interface design, and crystal fluctuations. Yet current theories lack a predictive description of the underlying interactions due to such structural modifications, highlighting the need for new tools that can capture these complex exciton dynamics.
Taking advantage of ever-growing computational frontiers, our research group aims to derive and apply new theoretical approaches, based on the predictive many-body perturbation theory, to compute exciton dynamics as a function of structural complexity in realistic materials. We explore and examine our approaches on emerging excitonic systems of reduced dimensionality, e.g., organic molecular crystals, layered transition metal dichalcogenides, and two-dimensional hybrid perovskites. We are particularly interested in studying the effect of atomic defects, heterostructure compositions, and lattice fluctuations on the mechanisms dominating exciton relaxation and diffusion and their resulting mobility and lifetime.
Rafaely’s research is thus focused on gaining a comprehensive and predictive understanding of the underlying physics dominating complex excited-state phenomena in materials of emerging interest via front-line computations. As such, Rafaely’s Lab aim at offering novel and tunable design principles for optimized functionality in applications ranging from efficient conversion and storage of sunlight energy to intelligent design of quantum emitters and materials-based quantum computing.