Optoelectronic properties of nonstoichiometric heterostructures

We review the optoelectronic properties of nonstoichiometric heterostructures, including the contribution to material absorption by arsenic precipitates in GaAs and the electroabsorption of quantum confined excitons in LTG quantum wells. These materials form the basis of adaptive holographic quantum well films used for adaptive optics applications. The optical applications rely on space-charge trapped in the deep energy levels which we calculate for spheroidal mesoscopic defects using an extension of the many-electron model of Haldane and Anderson. With electroabsorption spectroscopy we are able to establish details of vacancy migration and vacancy decay mechanisms during annealing.