Abstract

A theoretical study on shallow donor-impurity states in distinct triple GaAs-(Ga, Al)As quantum-well heterostructures is presented under external magnetic and electric fields applied perpendicular to the interfaces of the semiconducting elements. The emphasis is put on the determination of intra-donor absorption spectra and its dependence on the impurity profile distributions and different photon polarizations are considered. Impurity states are calculated by adopting the effective mass approximation and using a variational scheme in which ground and excited states are obtained simultaneously. Magnetospectroscopy measurements may be used to observe such transitions.