Scanning transmission electron microscopy (STEM) study of InAs/GaAs quantum dots

Murray, R., Malik, S., Siverns, P., Childs, D., Roberts, C., Joyce, B. and Davock, H. (1999) Scanning transmission electron microscopy (STEM) study of InAs/GaAs quantum dots. Japanese Journal of Applied Physics, 38(1B), pp. 496-499. (doi:10.1143/JJAP.38.496)

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Abstract

Scanning transmission electron microscopy (STEM) and energy dispersive X-ray analysis (EDX) have been used to investigate the size and composition of InAs/GaAs quantum dot (QDs). It is shown that the QD exist within the wetting layer and not on it. In QD bilayers where the dots are uncorrelated along the growth direction a comparison of the indium EDX signals from the wetting layer (WL) and a dot allow us to estimate the compositions of these regions as In0.07Ga0.93As and In0.31Ga0.69As respectively. We have used the STEM technique to investigate the effects of annealing QDs in order to modify the emission energy. EDX measurements show that the dots increase in size by a factor of 2 for the longest anneals and there is a concomitant decrease in the indium concentration resulting in blue shifts up to 300 meV and a narrowing of the linewidth to ∼12 meV.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Childs, Dr David
Authors: Murray, R., Malik, S., Siverns, P., Childs, D., Roberts, C., Joyce, B., and Davock, H.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Japanese Journal of Applied Physics
Publisher:Japan Society of Applied Physics
ISSN:0021-4922
ISSN (Online):1347-4065

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