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}Eᵥ=55±{}40 meV is obtained for the zero-strain valence-band offset and a relation between the CdTe (N₁) and ZnTe (N₂) monolayer numbers of the strained-layer superlattice (CdTe)N1/(ZnTe)N2 giving rise to a degenerate band gap [E(C1H1)=E(C1L1)] is proposed, N₁×{}N₂{}30. For N₁×{}N₂30, the band gap is E(C1H1), and the superlattice has a type-I configuration; for N₁×{}N₂>30, the band gap is E(C1L1), and the superlattice has a type-II configuration.