Exciton Dynamics in Quantum Dot Films and Interfaces

Colloidal quantum dots (QD) are a promising material platform for solution-processable optoelectronic devices such as solar cells, light-emitting diodes, thermoelectric modules, and flexible electronics. Central to the operation of these devices is the formation, transport, and conversion of free charges and excitons. In the first part of the talk, I will present a comprehensive study of exciton diffusion in inhomogeneously broadened QD assemblies, including spectrally-resolved transient photoluminescence spectroscopy, transient photoluminescence quenching, time-resolved optical imaging, and kinetic Monte Carlo simulations. In the second part of the talk, I will show how nanoscale dielectric screening phenomena in atomically thin semiconductors such as MoS$_{2}$ can lead to counterintuitive energy transfer behavior from QD donors.