A possible resolution of the valence-band offset controversy in HgTe/CdTe superlattices

Abstract

The valence-band offset controversy in HgTe/CdTe superlattices can be simply resolved by showing, as we do here, that a large offset value (Λ>300 meV) is indeed consistent with the magneto-optical data of Berroir et al. [Phys. Rev. B 34, 891 (1986)]. The superlattice (100 Å HgTe/36 Å CdTe) becomes semimetallic (SM) when Λ is increased from small values, but reverts to semiconducting (SC) behavior for Λ>300 meV. The band gap in this new regime occurs at the superlattice Brillouin zone face. The sensitivity to layer thicknesses of such SC→SM→SC transitions is discussed and experiments suggested.