| Autor: |
Mike L. W. Thewalt, O.J. Pitts, C. X. Wang, J. A. H. Stotz, Simon P. Watkins, T.A. Meyer |
| Rok vydání: |
2004 |
| Předmět: |
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| Zdroj: |
Journal of Crystal Growth. 269:187-194 |
| ISSN: |
0022-0248 |
| DOI: |
10.1016/j.jcrysgro.2004.05.013 |
| Popis: |
Heterostructures containing monolayer (ML) and submonolayer GaSb insertions in GaAs were grown using organometallic vapour phase epitaxy. At the GaAs-on-GaSb interface, strong intermixing occurs due to the surface segregation of Sb. To form structures with relatively abrupt interfaces, a flashoff growth sequence, in which growth interruptions are employed to desorb Sb from the surface, was introduced. Reflectance-difference spectroscopy and high-resolution X-ray diffraction data demonstrate that interfacial grading is strongly reduced by this procedure. For layer structures grown with the flashoff sequence, a GaSb coverage up to 1 ML can be obtained in the two-dimensional (2D) growth mode. For uncapped GaSb layers, on the other hand, atomic force microscope images show that the 2D–3D growth mode transition occurs at a submonolayer coverage between 0.3 and 0.5 ML. Low-temperature photoluminescence spectra of multiple quantum well samples grown using the flashoff sequence show a strong quantum well-related peak which shifts to lower energies as the amount of Sb incorporated increases. The PL peak energies are consistent with a type-II band lineup at the GaAs/GaSb interface. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect