Hopkins-Skellam index and origin of spatial regularity in InAs quantum dot formation on GaAs(001)

Journal Article · Tue Apr 14 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4917213· OSTI ID:22402844

Konishi, Tomoya; Tsukamoto, Shiro ^[1]; Bell, Gavin R. ^[2]

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1. Centre for Collaborative Research, National Institute of Technology, Anan College, Anan, Tokushima 774-0017 (Japan)
2. Department of Physics, University of Warwick, Coventry CV47AL (United Kingdom)

We investigate the origin of the spatial regularity of arrays of InAs quantum dots (QDs) grown on GaAs(001). The Hopkins-Skellam index (HSI) is used with a newly developed calculation algorithm to quantify the spatial regularity both of QDs and of nm-sized surface reconstruction territories (SRTs) present in the In{sub x}Ga{sub 1−x}As wetting layer prior to QD nucleation. The SRT is the minimum extent of a surface reconstruction region needed for one QD to nucleate. By computing the evolving HSI of SRTs from sequences of in situ scanning tunnelling microscopy images during growth, we find that the spatial regularity of QDs is traced back to that of the (n × 3) SRTs as early as 0.6 monolayers of InAs coverage. This regularity is disturbed by the (n × 4) SRTs which appear at higher coverage. The SRT approach is discussed in comparison to conventional capture zone theories of surface growth.

• OSTI ID: 22402844
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 14; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
ALGORITHMS
COMPARATIVE EVALUATIONS
CRYSTAL GROWTH
CRYSTAL STRUCTURE
GALLIUM ARSENIDES
IMAGES
INDIUM ARSENIDES
LAYERS
NUCLEATION
QUANTUM DOTS
SCANNING TUNNELING MICROSCOPY
SURFACES
X-RAY SPECTROSCOPY