Step-Bunching Evidence in Strained InxGa1?xAs/GaAs Quantum Wells Grown on Vicinal (001) Substrates

✍ Scribed by de Sales, F.V. ;Soler, M.A.G. ;Ugarte, D. ;Quivy, A.A. ;da Silva, S.W. ;Martini, S. ;Morais, P.C.

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 117 KB
• Volume: 187
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/1521-396x(200109)187:1<253::aid-pssa253>3.0.co;2-p

✦ Synopsis

In this study the influence of the interface morphology upon the photoluminescence of thick InGaAs/GaAs strained quantum wells has been investigated. Samples grown by molecular beam epitaxy, using GaAs (001) substrates with a miscut of 6 towards (111)A, have been studied using low temperature photoluminescence and transmission electron microscopy. The photoluminescence linewidth broadening was correlated with the interface morphology. The blueshift observed in the optical emissions of samples grown on vicinal substrate was well explained in terms of a simple model that includes indium segregation and strain modulation. Corrugation along the [110] direction, similar to "tiles", was observed in the 200 and 300 A thick quantum wells grown on vicinal substrate. Such observation was taken as an indication of the presence of step bunches at the upper interface of the quantum wells.