A new method for the calculation of the electronic structure of semiconductor superlattices in the envelope-function approximation is presented. The method is particularly suited to a description of type-II superlattices (e.g. InAs-GaSb). The band-edges of the constituent materials are realistically described, and appropriate boundary conditions are derived from the envelope functions. To determine the energy levels, a variational principle is obtained, which automatically produces correctly matched solutions and reduces the numerical work to a standard matrix diagonalization. Results are presented for InAs-GaSb superlattices. They reveal novel aspects of the band-crossing transition which occurs with increasing superlattice period and which produces a zero-gap or very-narrow-gap semiconductor state, rather than a true semimetal.
 

Application of High Magnetic Fields in Semiconductor Physics. Proceedings of the International Symposium Editor(s): Landwehr, G. Berlin, West Germany: Springer-Verlag, 1983. p.174-85 of xii+552 pp. 19 refs. Conference: Grenoble, France, 13-17 Sept 1982 ISBN: 3-540-11996-5.