PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, vol.17, pp.242-244, 2003 (SCI-Expanded)
We have investigated the temperature dependence of the band gap energy in GaInNAs, GaNAs and InGaAs quantum wells. In the structures containing nitrogen the well-known S-shaped characteristic was observed at low temperatures. We explain this anomalous temperature behaviour by strong carrier localization in potential fluctuations at low temperatures. In the nitrogen free samples, there was no S-shaped behaviour and the empirical Varshni dependence was followed. (C) 2002 Elsevier Science B.V. All rights reserved.