Wavelength elongation and improved emission efficiency of MOCVD-grown InAs quantum dots by GaNAs buffer layer

InAs quantum dots (QDs) on a GaNAs buffer layer by metalorganic chemical vapor deposition were investigated, focusing on the relation between the dot shape property and photoluminescence characteristics. Utilization of the GaNAs buffer layer restricted the dot evolution in the direction of height to result in the InAs supply independence of the emission wavelength. The nitrogen composition also influenced a little the dot shape. The emission efficiency was improved by the change of the dot morphology. The peak wavelength of 1280 nm, which was 40 nm increase from the sample without GaNAs, was obtained from InAs QDs on a GaNAs buffer layer with high intensity. (c) 2006 Published by Elsevier B.V.