Reduction of the internal electric field in GaN/AlN quantum dots grown on the a ‐plane of SiC substrates

We present a study of the emission of a multi-layer stack of self-assembled GaN/AlN quantum dots grown on the a -plane of 6H-SiC. We look for signatures of the internal electric field in the power dependence of the time-integrated and time-resolved photoluminescence spectra. The lack of a dynamical red-shift reveals that internal electric fields are significantly reduced in these dots. A band on the low energy side of the emission is observed whose intensity quenches fast when increasing the temperature. The polarization selection rules of the emission are examined in order to determine the physical nature of this band. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)