The free-carrier screening of macroscopic polarization fields in wurtzite GaN/InGaN quantum wells lasers is investigated via a self-consistent tight-binding approach. We show that the high carrier concentrations found experimentally in nitride laser structures effectively screen the built-in spontaneous and piezoelectric polarization fields, thus inducing a ``field-free'' band profile. Our results explain some heretofore puzzling experimental data on nitride lasers, such as the unusually high lasing excitation thresholds and emission blue-shifts for increasing excitation levels.
@article{arxiv.cond-mat/9809409,
title = {Free-carrier screening of polarization fields in wurtzite GaN/InGaN laser structures},
author = {F. Della Sala and A. Di Carlo and P. Lugli and F. Bernardini and V. Fiorentini and R. Scholz and J. -M. Jancu},
journal= {arXiv preprint arXiv:cond-mat/9809409},
year = {2009}
}