BeTe-ZnSe type-II heterojunctions

BeTe-ZnSe heterojunctions are interesting model systems, where the interfac e is made of materials which are almost lattice matched, but have no common anion nor cation. As a consequence, there are two interface configurations , which are basically reflected by a "ZnTe" and a "BeSe" interfacial layer. To a certain extent, the interface configuration can be controlled by the MBE growth mode, and has an important impact on structural, electronical an d optical properties of the heterojunction. The two possible interface conf igurations drastically influence the strain state and the band offset. The averaged lattice constant of small period BeTe-ZnSe superlattices can be us ed for an analysis of the interface composition. Spatially indirect electro n-hole recombination is linearly polarized due to the particular bond orien tation at the interface. Surface emitting type-II LEDs with a linear polari zed emission have been fabricated. (C) 2000 Elsevier Science B.V. All right s reserved.