Tight-binding study of interface states in semiconductor heterojunctions
Abstract
Localized interface states in abrupt semiconductor heterojunctions are studied within a tight-binding model. The intention is to provide a microscopic foundation for the results of similar studies which were based on the two-band model within the envelope-function approximation. In a two-dimensional description, the tight-binding Hamiltonian is constructed such that the Dirac-like bulk spectrum of the two-band model is recovered in the continuum limit. Localized states in heterojunctions are shown to occur under conditions equivalent to those of the two-band model. In particular, shallow interface states are identified in noninverted junctions with intersecting bulk dispersion curves. As a specific example, the GaSb-AlSb heterojunction is considered. The matching conditions of the envelope-function approximation are analyzed within the tight-binding description.
- Publication:
-
Physical Review B
- Pub Date:
- May 2001
- DOI:
- 10.1103/PhysRevB.63.205322
- arXiv:
- arXiv:cond-mat/0102128
- Bibcode:
- 2001PhRvB..63t5322K
- Keywords:
-
- 73.40.Lq;
- 73.20.Fz;
- Other semiconductor-to-semiconductor contacts p-n junctions and heterojunctions;
- Weak or Anderson localization;
- Condensed Matter - Materials Science;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- RevTeX, 11 pages, 3 figures, to appear in Phys. Rev. B