MOLECULAR-BEAM EPITAXY OF BERYLLIUM-CHALCOGENIDE-BASED THIN-FILMS ANDQUANTUM-WELL STRUCTURES

A variety of BeMgZnSe-ZnSe- as well as BeTe-based quantum-well structu res has been fabricated and investigated. BeTe buffer layers improve t he growth start on GaAs substrates drastically compared to ZnSe/GaAs. The valence-band offset between BeTe and ZnSe has been determined to b e 0.9 eV (type II). Due to the high-lying valence band of BeTe, a BeTe -ZnSe pseudograding can be used for an efficient electrical contact be tween p-ZnSe and p-GaAs. BeMgZnSe quaternary thin-film structures have reproducibly been grown with high structural quality, and rocking cur ve widths below 20 arcsec could be reached. Quantum-well structures sh ow a high photoluminescence intensity even at room temperature. (C) 19 96 American Institute of Physics.