Band offsets at interfaces between HgTe, CdTe, and InSb Available to Purchase

We have performed self‐consistent density‐functional calculations in order to determine the electronic structure and band offsets at ideal (110) interfaces between HgTe, CdTe, and InSb. These materials are very nearly lattice matched; strains due to the small lattice mismatch have negligible effects on the lineups. Local‐density‐functional theory, together with ab initio pseudopotentials, is used to calculate charge densities and potentials for the interface system; this allows us to determine the lineup of the bulk band structures. The following valence‐band discontinuities are derived: 0.27 eV for CdTe/HgTe, 0.91 eV for HgTe/InSb, and 1.19 eV for CdTe/InSb. These values obey the transitivity rule. For HgTe/CdTe, we also examined the (100) and (111) interface orientations; the valence‐band offset is the same in all cases. We have also used our simpler ‘‘model solid’’ approach to predict the lineups; the results are in very good agreement with those from the self‐consistent interface calculations. Noticeable differences are found, however, with values obtained from model theories by Tersoff and by Harrison. Our value for HgTe/CdTe also clearly differs from ΔE_v≊0, predicted by the common anion rule. Results for alloys can be obtained by interpolating our results for ΔE_v for the pure materials. We discuss how changing the alloy composition x in Hg_xCd_1−xTe/InSb interfaces can result in varying the band offsets over a wide range of values. Finally, we present a discussion of the experimental values that have been reported for HgTe/CdTe, and find good agreement between our theoretical value and the experimental result obtained from photoemission data.