Static and dynamic screening of the polarization fields in nitride nanostructures: a theoretical and experimental study

We present a combined theoretical and experimental analysis to describe the
interplay between polarization field, charge screening and radiative and
non-radiative recombinations in GaN-based nanostructure. The theoretical
analysis is obtained by coupling a self-consistent solution of Schrödinger
and Poisson equations to determine the electronic states in the
nanostructure with a rate equation model to account for time-dependent
effects of charge re-arrangement. Experimental results are obtained for
high quality GaN–AlGaN multiple quantum wells by means of both CW and time
resolved photoluminescence techniques. We demonstrate that PL emission is
influenced by charge accumulation in the well, and loss of carriers from
the ground level induced by both radiative and non-radiative recombination
processes.