Effect of lattice ionicity on hydrogen activity in II–VI materials containing isoelectronic oxygen impurities

Abstract

The authors studied the effect of hydrogen irradiation on the optical properties of ZnTe, ZnTe1−ySy (y=0.015) and ZnSe1−xOx (x=0.0023, 0.0057 and 0.009) epilayers. Photoluminescence measurements show the full passivation of O-related recombination bands in ZnTe and ZnTe0.985S0.015 samples unintentionally doped with oxygen. However, hydrogen irradiation does not affect the bandgap reduction following O incorporation in ZnSe1−xOx alloys. This lack of interaction between O and H in ZnSe1−xOx points toward a scarce localised character in the ZnSe1−xOx band edges, as supported by the study of the temperature dependence of the ZnSe1−xOx bandgap.