title: Raman scattering study on Sb spray InAs/GaAs quantum dot nanostructure systems.
abstract: The effect of Sb spray time on the structure of InAs/GaAs quantum dot (QD) systems with Sb spray prior to the capping of a GaAs layer was determined by a Raman scattering study. The Raman spectra of the InAs/GaAs system show two phonon signal bands related to interface (IF) defects, located at the low-energy side of InAs QDs and GaAs cap layer main phonon peaks, respectively. The intensity ratio of the IF defect relative phonon signal to its corresponding main peak shows a significant decrease with the Sb spray time increasing from 0 to 15 s, but increases for spray times larger than 15 s. In addition, the InAs QD phonon peaks appear to be resolved with improved symmetry for 15 s of spray time. Finally, the GaAs transverse optical (TO) phonon peak is seen to vary with Sb spray time, both in terms of the intensity and the peak position, in a similar manner to the other results. Taken together, these results suggest the InAs/GaAs QDs with a 15-s Sb spray lead to a GaAs capping layer with less strain at the IF with the QDs and a lower density of crystalline defects.
  81.05.Ea; 81.07.-b; 81.07.Ta.
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, No 4, Section 2, Jianshe North Road, Chengdu, 610054 China ; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Chemical Engineering Building, Sydney, 2006 Australia.
authors.forename: Liping
authors.initials: L
authors.lastname: Dai
authors.affiliation: School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, 2052 Australia.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Bremner
authors.affiliation: Australian Centre for Microscopy and Microanalysis, The University of Sydney, Chemical Engineering Building, Sydney, 2006 Australia.
authors.forename: Shenwei
authors.initials: S
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, No 4, Section 2, Jianshe North Road, Chengdu, 610054 China.
authors.forename: Shuya
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, No 4, Section 2, Jianshe North Road, Chengdu, 610054 China.
authors.forename: Guojun
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Australian Centre for Microscopy and Microanalysis, The University of Sydney, Chemical Engineering Building, Sydney, 2006 Australia.
authors.forename: Zongwen
authors.initials: Z
authors.lastname: Liu
keywords: InAs; Quantum dots; Raman spectra; Sb spray