Optical band-gap shift in (InAs)GaAs/AlGaAs HEMTs structures studied by photoluminescence spectroscopy

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-δ-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.