Effect of growth rate on the size, composition, and optical properties of InAs/GaAs quantum dots grown by molecular-beam epitaxy

Citation
Pb. Joyce et al., Effect of growth rate on the size, composition, and optical properties of InAs/GaAs quantum dots grown by molecular-beam epitaxy, PHYS REV B, 62(16), 2000, pp. 10891-10895
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B
ISSN journal
0163-1829 → ACNP
Volume
62
Issue
16
Year of publication
2000
Pages
10891 - 10895
Database
ISI
SICI code
0163-1829(20001015)62:16<10891:EOGROT>2.0.ZU;2-R
Abstract
The effect of the InAs deposition rate on the properties of InAs/GaAs quant um dots (QD's) grown on GaAs(001) substrates by molecular-beam epitaxy has been studied by scanning tunneling microscopy (STM) and photoluminescence ( PL). PL studies performed on GaAs capped QD samples show that the emission wavelength increases with decreasing growth rate, reaching a maximum around 1.3 mum, with the linewidth decreasing from 44 to 27 meV. STM studies on u ncapped dots show that the number density, total QD volume, and size fluctu ation all decrease significantly as the growth rate is reduced. We deduce t hat the composition of the dots is also dependent on the growth rate, the i ndium fraction being highest at the lowest growth rates. The shifts in the emission wavelength and linewidth correlate with changes in the QD size, si ze distribution, and composition.