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

Abstract

A variety of BeMgZnSe–ZnSe- as well as BeTe-based quantum-well structures has been fabri- cated and investigated. BeTe buffer layers improve the growth start on GaAs substrates drasti- cally 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 struc- tural quality, and rocking curve widths below 20 arcsec could be reached. Quantum-well structures show a high photoluminescence intensity even at room temperature.

Research challenges to ultra‐efficient inorganic solid‐state lighting

“…Significant progress in device lifetime has been achieved by circumventing the relatively weak bonding and pronounced electrical activity and mobility of defects in ZnSe-based materials. As one example, Be-containing alloys have been employed to enhance the bond strength of the active region materials [98]. The implementation of ZnMgBeSe electron blocking layers has also enabled the reduction of recombinationenhanced defect reaction which is triggered by electron overflow into the p-cladding layer [62].…”

Ab Initio Study of the Mechanical Stability Criteria in BeSe and BeTe under Hydrostatic Pressure

“…However, little is known about the ground-state properties of the beryllium chalcogenides. These materials are potentially good for technological applications, mainly for blue-green laser diodes and laser-emitting diodes [3].…”

Optical and interface phonons of different kind in BeTe/ZnSe superlattices

“…Calculated frequencies of the interface modes are compared with the experimental ones. The BeTe/ZnSe are novel SLs that belong to the type II band alignment with very large band offsets [3]. The conduction band minimum is in ZnSe layers and the valence band maximum in BeTe ones.…”