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 Schrodinger 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. (C) 2002 Elsevier Science B.V. All rights reserved.