Dai L, Bremner SP, Tan S, Wang S, Zhang G, Liu Z. Raman scattering study on Sb spray InAs/GaAs quantum dot nanostructure systems.
NANOSCALE RESEARCH LETTERS 2015;
10:202. [PMID:
25977672 PMCID:
PMC4420766 DOI:
10.1186/s11671-015-0908-1]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/20/2015] [Indexed: 06/04/2023]
Abstract
UNLABELLED
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.
PACS
81.05.Ea; 81.07.-b; 81.07.Ta.
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