Abstract
The optical band-gap has been investigated in detail in (InAs)GaAs/AlGaAs HEMTs structures using a photoluminescence spectroscopy. A power dependent PL study allows highlighting the different causes of the shift band-gap. We can explain the shift by more effects: quantum confined Stark effect (QCSE), band-gap renormalisation (BGR) and Burstein-Moss (BM) effects. We are interested in these effects based on the carriers' behaviour inside GaAs and InAs/GaAs channels. These effects were affected by carrier concentration depending on Si-delta-doping density and AlGaAs spacer layer thickness as well as the strain relaxation effect. The photoluminescence characterisations have been studied in the 1-10 W cm(-2) power range. (C) 2015 Elsevier GmbH. All rights reserved.