Abstract
The quantum confined Stark effect (QCSE) has been investigated in detail in GaAs/AlGaAs and InAs/GaAs/AlGaAs HEMTs structures grown by molecular beam epitaxy on (1 0 0) oriented GaAs substrates. A power dependent photoluminescence (PL) study allowed to highlight the QCSE caused by the internal electric field in the GaAs channel then a piezoelectric field reinforce the red-shift. Increasing the Si-delta-doping leads to; first a red-shift then a blue shift at high excitation power due to the stabilize quantum well structures tendency and the saturation phenomenon. The HEMT band structures and the theoretical activated electron densities at 10 K have been studied using the finite difference method and the simultaneously solve of the Schrodinger and the Poisson equations written within the Hartree approximation.