Subband structure of strained-layer CdTe/ZnTe superlattices: A reexamination

With recent new values of the CdTe deformation potentials, we present a reexamination of the combined effects of band offsets and lattice mismatch on the subband structure of strained-layer CdTe/ZnTe superlattices. It is shown that the subband structure of these superlattices is very sensitive to the strain parameters. The value Δ${\mathit{E}}_{\mathit{v}}$=55±40 meV is obtained for the zero-strain valence-band offset and a relation between the CdTe (${\mathit{N}}_1$) and ZnTe (${\mathit{N}}_2$) monolayer numbers of the strained-layer superlattice (CdTe${)}_{\mathit{N}1}$/(ZnTe${)}_{\mathit{N}2}$ giving rise to a degenerate band gap [E(C1H1)=E(C1L1)] is proposed, ${\mathit{N}}_1$×${\mathit{N}}_2$≃30. For ${\mathit{N}}_1$×${\mathit{N}}_2$E(C1H1), and the superlattice has a type-I configuration; for ${\mathit{N}}_1$×${\mathit{N}}_2$>30, the band gap is E(C1L1), and the superlattice has a type-II configuration.