Optimising uniformity of InAs/(InGaAs)/GaAs quantum dots grown by metal organic vapor phase epitaxy
2006 (English)In: Applied Surface Science, ISSN 0169-4332, Vol. 252, no 15, 5525-5529 p.Article in journal (Refereed) Published
A route towards optimisation of uniformity and density of InAs/(InGaAs)/GaAs quantum dots grown by metal organic vapor phase epitaxy (MOVPE) through successive variations of the growth parameters is reported. It is demonstrated that a key parameter in obtaining a high density of quantum dots is the V/III ratio, a fact which was shown to be valid when either AsH3 (arsine) or tertiary-butyl-arsine (TBA) were used as group V precursors. Once the optimum V/III ratio was found, the size distribution was further improved by adjusting the nominal thickness of deposited InAs material, resulting in an optimum thickness of 1.8 monolayers of InAs in our case. The number of coalesced dots was minimised by adjusting the growth interruption time to approximately 30 s. Further, the uniformity was improved by increasing the growth temperature from 485 °C to 520 °C. By combining these optimised parameters, i.e. a growth temperature of 520 °C, 1.8 monolayers InAs thickness, 30 s growth stop time and TBA as group V precursor, a full-width-half-maximum (FWHM) of the low temperature luminescence band of 40 meV was achieved, indicating a narrow dot size distribution.
Place, publisher, year, edition, pages
Elsevier , 2006. Vol. 252, no 15, 5525-5529 p.
Quantum dot, Epitaxy, MOVPE, InAs/GaAs, TBA, Growth
National CategoryOther Engineering and Technologies not elsewhere specified
IdentifiersURN: urn:nbn:se:liu:diva-15764DOI: 10.1016/j.apsusc.2005.12.128OAI: oai:DiVA.org:liu-15764DiVA: diva2:127226
Linda Höglund, E. Petrini, C. Asplund, H. Malm, J. Y. Andersson and Per-Olof Holtz, Optimising uniformity of InAs/(InGaAs)/GaAs quantum dots grown by metal organic vapor phase epitaxy, 2006, Applied Surface Science, (252), 15, 5525-5529 .
Copyright: Elsevier Science B.V., Amsterdam.