Microscopic modeling of GaN-based heterostructures

The realization of blue lasers and power HEMTs has brought a lot of attention to nitride-based heterostructures. When grown in the wurtzite structures (which is actually the most interesting one), nitrides display a non-zero macroscopic polarization, comprising both a spontaneous and a piezoelectric component. Such polarization induces an internal electric field, which modifies quite profoundly the properties of nitride-based heterostructures with respect to more standard systems based for example on GaAs. Because of the polarization field, we have a strong (width-dependent) Stark shift in the luminescence of quantum wells, or growth-direction dependence of the channel properties of HEMTs. In the present communication we investigate the optical and transport properties of nitride-based multi-quantum well systems and devices.