Carrier screening and polarization fields in nitride-based heterostructure devices

We have shown that free carriers and fixed doping charges can effectively screen macroscopic spontaneous and piezoelectric polarization fields in nitride quantum wells. A rather high sheet density is needed to achieve these conditions. We also explain the red shifts versus well width and blue shifts versus sheet density observed in the experiments as resulting from the interplay of carrier screening and polarization fields. (C) 1999 Elsevier Science B.V. All rights reserved.