The electronic properties of the strained CdTe/ZnTe(001) superlattices

The common-anion II-VI semiconductor superlattices (SLs) are characterized by a vanishing or a small valence-band offset (VBO). In the case of the lattice-mismatched SLs, the biaxial strain can drastically affect the splitting of the valence-band top states, and therefore be explored in designing type-I character SLs. In the present work, we used the sp³s* tight-binding method, with the inclusion of strain and spin-orbit coupling effects, to investigate the electronic band structures of the strained CdTe/ZnTe(001) SLs versus the biaxial strain, layer thicknesses and VBO. Our results show that the electron is always confined within the CdTe slabs, whereas the hole behaviour controls the whole SL character. Our theoretical results are compared to the photoluminescence experiments and shown to be consistent with the strain morphology along the SL growth direction as well as the optical and structural qualities of the experimental samples.