Enhanced optical properties of in situ passivated near-surface AlxGa1-xAs/GaAs quantum wells

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Journal Title
Journal ISSN
Volume Title
School of Electrical Engineering | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
1996
Major/Subject
Mcode
Degree programme
Language
en
Pages
2216-2218
Series
Applied Physics Letters, Volume 68, Issue 16
Abstract
An epitaxial method for in situpassivation of epitaxial Al x Ga1−x As/GaAs surfaces is reported. The deposition of an ultrathin InP layer (about one monolayer) on the surface of Al x Ga1−x As/GaAs structures by metalorganic vapor phase epitaxy results in drastically reduced surface recombination. The effect is studied by low‐temperature photoluminescence of near‐surface Al0.22Ga0.78As/GaAs quantum wells where the top barrier thickness is varied from 0 to 50 nm. At the thicknesses of ≤5 nm, the intensity from passivated samples is more than four orders of magnitude larger than that obtained from unpassivated structures. For a passivated surfacequantum well where InP is deposited directly onto the GaAsquantum well, we observe a blueshift of 15 meV and an intensity reduction of only a factor of 10 as compared to the luminescence from a quantum well placed at a depth of 50 nm from the surface.
Description
Keywords
optoelectronics, III-V semiconductors, quantum wells, surface passivation, epitaxy, surface structure
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Citation
Lipsanen, Harri & Sopanen, M. & Taskinen, M. & Tulkki, J. & Ahopelto, J. 1996. Enhanced optical properties of in situ passivated near-surface AlxGa1-xAs/GaAs quantum wells. Applied Physics Letters. Volume 68, Issue 16. P. 2216-2218. ISSN 0003-6951 (printed). DOI: 10.1063/1.115863.