Transitivity of the band offsets in II-VI/III-V heterojunctions

The band discontinuities in ZnSe/AlAs(0 0 1) heterojunctions fabricated by molecular beam epitaxy are found to depend on the local interface composition in a manner reminescent of what was found earlier for ZnSe/GaAs(0 0 1) heterojunctions. Se-rich interface compositions correspond to valence band offsets as low as 0.2 eV, while Zn-rich interface compositions yield valence band offsets as high as 0.9 eV. When similar interface compositions are considered, the band offsets for ZnSe/AlAs and ZnSe/GaAs heterojunctions follow the predictions of the transitivity rule.