| Autor: |
Anantathanasarn, S., Nötzel, R., van Veldhoven, P. J., Eijkemans, T. J., Wolter, J. H. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 7/1/2005, Vol. 98 Issue 1, p013503, 7p, 1 Color Photograph, 1 Diagram, 6 Graphs |
| Abstrakt: |
Growth of wavelength-tunable InAs quantum dots (QDs) embedded in a lattice-matched InGaAsP matrix on InP (100) substrates by metal-organic vapor-phase epitaxy is demonstrated. As/P exchange plays an important role in determining QD size and emission wavelength. The As/P exchange reaction is suppressed by decreasing the QD growth temperature and the V/III flow ratio, reducing the QD size and emission wavelength. The As/P exchange reaction and QD emission wavelength are then reproducibly controlled by the thickness of an ultrathin [zero to two monolayers (MLs)] GaAs interlayer underneath the QDs. An extended interruption after GaAs interlayer growth is essential to obtain well-defined InAs QDs. Submonolayer GaAs coverages result in a shape transition from QD to quantum dash at low V/III flow ratio with a slightly shorter emission wavelength. Only the combination of reduced growth temperature and V/III flow ratio with the insertion of GaAs interlayers above ML thicknesses allows wavelength tuning of QDs at room temperature in the technologically important 1.55-μm wavelength region for fiber-optical telecommunication systems. A GaAs interlayer thickness just above one ML produces the highest photoluminescence (PL) efficiency. Temperature-dependent PL measurements reveal zero-dimensional carrier confinement and defect-free InAs QDs. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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