Photoluminescence, Raman scattering and vertical transport of CdSe/CdMgSe superlattices

✍ Scribed by I. I. Reshina; S. V. Ivanov; D. N. Mirlin; I. V. Sedova; S. V. Sorokin

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 220 KB
• Volume: 3
• Category: Article
• ISSN: 1862-6351
• DOI: 10.1002/pssc.200564621

✦ Synopsis

Abstract

Photoluminescence and photoluminescence excitation spectra, vertical transport of photoexcited charge carriers and excitons and Raman scattering by optical phonons have been studied for the first time in low‐strained superlattices CdSe/CdMgSe grown by molecular‐beam epitaxy on InAs substrates. The vertical transport was studied by purely optical means involving an enlarged quantum well built into the superlattice. The enlarged quantum well served as a sink for the photoexcited carriers and excitons that have tunnelled through the superlattice. The measurements conducted in temperature range 2–150 K and also under in‐plane strong magnetic fields show that vertical transport occurs mainly by free heavy‐hole excitons but in superlattices with 5.9 nm and 7.3 nm periods it is not of the Bloch type. A comparison of the calculated energies of the interband transitions with the experimental data provides the valence‐band ofsett in the range 0.4–0.5. The Raman spectra indicate a two‐mode behavior of the optical phonons in CdMgSe barriers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)