DEUTERIUM IN INGAAS GAAS STRAINED QUANTUM-WELLS - AN OPTICALLY-ACTIVEIMPURITY/

Low-temperature photoluminescence in InGaAs/GaAs strained quantum well s shows the appearance, upon deuterium irradiation, of two bands at en ergies below the heavy-hole free exciton. The deeper band is due to re combination at a deuterium impurity (or at a deuterium-defect complex) , while the shallower band is attributed to an exciton bound to the de uterium-related state. The binding energies of these two bands depend on alloy composition and well width and show a maximum for finite well width values as expected by theoretical calculations. The absence of these bands in samples irradiated with helium shows that the two bands are related to deuterium atoms in the samples rather than to recombin ation centres due to the irradiation procedure. Thermal annealing trea tments indicate that the dissociation energy of the deuterium-related radiative state is comparable to that measured in GaAs for complexes f ormed by deuterium and deep traps.