Theoretical and experimental analysis of the photoluminescence and photoluminescence excitation spectroscopy spectra of m-plane InGaN/GaN quantum wells

We present a combined theoretical and experimental analysis of theoptical properties ofm-plane InGaN/GaNquantum wells. The sample was studied byphotoluminescence andphotoluminescence excitation spectroscopy at low temperature. Thespectra show a large Stokes shift between the lowestexciton peak in the excitationspectra and the peak of thephotoluminescencespectrum. This behavior is indicative of strong carrierlocalization effects. These experimental results are complemented by tight-binding calculations, accounting for randomalloy fluctuations and Coulomb effects. The theoretical data explain the main features of the experimentalspectra. Moreover, by comparison with calculations based on a virtual crystal approximation, the importance of carrierlocalization effects due to randomalloy fluctuations is explicitly shown.

Source: Applied Physics Letters - November 28, 2016 Category: Physics Authors: S. Schulz, D. S. P. Tanner, E. P. O'Reilly, M. A. Caro, F. Tang, J. T. Griffiths, F. Oehler, M. J. Kappers, R. A. Oliver, C. J. Humphreys, D. Sutherland, M. J. Davies and P. Dawson Source Type: research