Abstract
We present a study of optical properties in GaN based structures and devices. Our approach is based on a rate equation model, where the role of carrier screening on recombination rates is self-consistently included. We demonstrate that Time-Resolved Photoluminescence (TR-PL) in gallium-nitride quantum wells is influenced by two main effects: (i) the charge accumulation in the well, caused by the separation of the wavefunctions and by the increase of the radiative recombination time induced by the built-in field, and (ii) the loss of carriers from the ground level induced by the non-radiative recombination processes.