GaInN quantum well design and measurement conditions affecting the emission energy S-shape

Polarization fields and charge carrier localization are the dominant factors defining the radiative recombination processes in the quantum wells of most AlGaInN‐based optoelectronic devices. Both factors determine emission energy, emission line width, recombination times, and internal quantum efficiency. For a deeper understanding of the charge carrier recombination processes, we have performed temperature and excitation power dependent photoluminescence experiments on epitaxially grown GaInN structures to study the S‐shape of the temperature dependent emission energy. The S‐shape behaviour in GaInN quantum wells (QWs) is dominated by the temperature dependence of the charge carrier localization. However, in polar QWs it is strongly affected by the charge carrier density which screens the piezoelectric field. External applied fields change the observable S‐shape characteristic significantly. Semi‐ and nonpolar GaInN QWs feature an S‐shape behaviour which points to much stronger charge carrier localization compared to polar QWs. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)