Dependence of ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$${\mathrm{Cd}}_{\mathrm{x}}$Te-CdTe superlattice band structure on well and barrier thickness, strain, valence-band offset, and well composition

Qualitative dependencies of theoretical ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Cd}}_{\mathrm{x}}$Te-CdTe superlattice band-structure features on input parameters (such as well and barrier thickness, strain, valence-band offset, and well composition) are systematically considered with use of a tight-binding calculation. The effect of varying the layer thicknesses in the superlattice is compared with varying the composition x in the ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Cd}}_{\mathrm{x}}$Te alloy. It is shown that many of the qualitative trends can be understood from relatively simple analytical expressions derived from one-band and two-band calculations. The transport and magnetooptical properties depend strongly on whether the highest valence band is light-hole–like or heavy-hole–like. When the effects of both strain and valence-band offset, Λ, are considered, comparison with experimental results yields Λ>≊200 meV.