Passivation of an isoelectronic impurity by atomic hydrogen: The case of ZnTe:O

We investigated the optical properties of ZnTe:O∕GaAs before and after atomic hydrogen irradiation. Oxygen incorporation gives rise to energy levels associated with single O atoms, O–O pairs, and O clusters, and to a blueshift of the energy gap of the material with respect to that of pure ZnTe∕GaAs. All of these effects disappear progressively after irradiation with H, which also leads to an increase in the tensile strain of the epilayer. These observations provide experimental evidence of H-induced passivation of an isoelectronic impurity in II–VI alloys.