Influence of growth kinetics on the indium distribution during MOVPE growth of GaInN quantum wells

The composition and thickness of GaInN quantum wells (QWs) determines the luminescence properties of GaInN/GaN-based optoelectronic devices. The In distribution is characterized by considerable inhomogeneities on two spatial scales. Variations of locally averaged In concentrations and QW thickness on a "large" scale of several 10 nm along the QW occur in addition to small clusters with high In concentrations up to 100% and sizes of only a few nanometers. In the present work, we investigated the influence of the growth rate during metal organic vapor phase epitaxy (MOVPE) growth on the In distribution. The composition of GaInN single QWs was determined by evaluating high-resolution transmission electron microscopy (HRTEM) lattice-fringe images. At low GaInN deposition rates, a significant increase of the inhomogeneity of the In distribution compared to a sample grown with a high rate was found. A good correlation between experimental and calculated photoluminescence energies is achieved. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.