• DOI:10.1103/PHYSREVB.52.12039
• Corpus ID: 38272832

InAsSb/InAs: A type-I or a type-II band alignment.

@article{Wei1995InAsSbInAsAT,
  title={InAsSb/InAs: A type-I or a type-II band alignment.},
  author={Wei and Zunger},
  journal={Physical review. B, Condensed matter},
  year={1995},
  volume={52 16},
  pages={
          12039-12044
        }
}

• Wei, Zunger
• Published 15 October 1995
• Materials Science
• Physical review. B, Condensed matter

Using first-principles band-structure calculations we have studied the valence-band alignment of InAs/InSb, deducing also the offset at the ${\mathrm{InAs}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sb}}_{\mathit{x}}$/${\mathrm{InAs}}_{1\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{Sb}}_{\mathit{y}}$ heterostructure. We find the following: (i) Pure InAs/InSb has a ``type-II broken gap'' alignment both with and without strain. (ii) For Sb-rich ${\mathrm{InAs}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sb}}_{\mathit{x}}$/InSb heterostructures, the unstrained band alignment is type II; both epitaxial strain and CuPt ordering enhance the type-II character in this Sb-rich limit. (iii) For As-rich InAs/${\mathrm{InAs}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sb}}_{\mathit{x}}$ heterostructures the top of the valence band is always on the alloy layer while the conduction-band minimum can be localized either on the alloy layer (type-I) or on the InAs layer (type-II), depending on the balance between concentration, strain, and degree of ordering/phase separation. In this case, epitaxial strain enhances the type-II character, while ordering enhances the type-I character. Our results are compared with recent experimental observations. We find that the type-I behavior noted for some As-rich InAs/${\mathrm{InAs}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sb}}_{\mathit{x}}$ interfaces and the type-II behavior noted in other such samples could be explained in terms of the dominance of ordering and strain effects, respectively.