  The joint impact of Anderson localization and many-body interaction is
observed in the optical properties of strongly-disordered III-nitride quantum
wells, a system where the Coulomb interaction and the fluctuating potential are
pronounced effects with similar magnitude. A numerical method is introduced to
solve the 6-dimensional coupled Schrodinger equation in the presence of
disorder and Coulomb interaction, a challenging numerical task. It accurately
reproduces the measured absorption and luminescence dynamics of InGaN quantum
wells at room-temperature: absorption spectra reveal the existence of a
broadened excitonic peak, and carrier lifetime measurements show that
luminescence departs from a conventional bimolecular behavior. These results
reveal that luminescence is governed by the interplay between localization and
Coulomb interaction, and provide practical insight in the physics of modern
light-emitting diodes.
