Quasibound states in type-II ZnTe/CdSe superlattices studied by modulationspectroscopies and photoconductivity at room temperature - art. no. 195311

We report that the quasibound states at the above-barrier region in type-II ZnTe/CdSe superlattices can be clearly observed at room temperature by pho toreflectance, contactless electroreflectance, as well as photoconductivity measurements. We provide concrete evidence to confirm that free-carrier co nfinement at barrier layer (either in the valence-band CdSe layer or in the conduction-band ZnTe layer) does exist. It is found that the barrier-width dependence of the above-barrier ground-state transition energies can be de scribed well by the constructive interference condition. We also observe th e absorptive spatially indirect transition between electrons confined in th e CdSe and holes confined in the ZnTe layers.