Molecular-beam epitaxy of beryllium-chalcogenide-based thin films and quantum-well structures

A variety of BeMgZnSe-ZnSe- as well as BeTe-based quantum-well structures has been fabricated and investigated. BeTe buffer layers improve the growth start on GaAs substrates drastically compared to ZnSe/GaAs. The valence-band offset between BeTe and ZnSe has been determined to be 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 between p-ZnSe and p-GaAs. BeMgZnSe quaternary thin-film structures have reproducibly been grown with high structural quality, and rocking curve widths below 20 arcsec could be reached. Quantum-well structures show a high photoluminescence intensity even at room temperature. (C) 1996 American Institute of Physics.