CALCULATION OF BAND OFFSETS IN STRAINED II-VI HETEROJUNCTIONS

The self-consistent tight-binding description of unstrained and strained heterojunctions has recently provided theoretical values for the offset of the average valence band ΔEavv which agree well with experimental data for III-V and II-VI semiconductor compounds. We present here calculations of ΔEavv in other strained heterojunctions with common anion or cation atoms such as ZnS, ZnSe, ZnTe, HgTe and CdTe. The charge transfer in the interface neighbourhood is taken into account by a self-consistent description using realistic values of the dielectric constant ε (q). First, we have obtained the hydrostatic deformation potentials. Then the ΔEavv are calculated for different situations which can occur for strained heterojunctions according to the strain is confined (i) to one side of the heterojunction as, for instance, CdTe strained to ZnTe or (ii) to the other side: ZnTe strained to CdTe. Results are discussed and compared with those obtained for similar compounds and also to experimental values. © 1989.