Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach

Journal Article · Tue Nov 15 00:00:00 EST 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.72.195334· OSTI ID:20719831

Schmidt, Th; Roventa, E; Clausen, T; Flege, J I; Alexe, G; Rosenauer, A; Hommel, D; Falta, J ^[1]; Bernstorff, S ^[2]; Kuebel, C ^[3]

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1. Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28 359 Bremen (Germany)
2. ELETTRA Synchrotron Light Source, Strada Statale 14, 34012 Basovizza (Italy)
3. IFAM Adhesive Bonding Technology and Surfaces, Wiener Str. 12, D-28 359 Bremen (Germany)

The vertical and lateral ordering of stacked CdSe quantum dot layers embedded in ZnS{sub x}Se{sub 1-x} has been investigated by means of grazing incidence small angle x-ray scattering and transmission electron microscopy. Different growth parameters have been varied in order to elucidate the mechanisms leading to quantum dot correlation. From the results obtained for different numbers of quantum dot layers, we conclude on a self-organized process which leads to increasing ordering for progressive stacking. The dependence on the spacer layer thickness indicates that strain induced by lattice mismatch drives the ordering process, which starts to break down for too thick spacer layers in a thickness range from 45 to 80 A. Typical quantum dot distances in a range from about 110 to 160 A have been found. A pronounced anisotropy of the quantum dot correlation has been observed, with the strongest ordering along the [110] direction. Since an increased ordering is found with increasing growth temperature, the formation of stacking faults as an additional mechanism for quantum dot alignment can be ruled out.

• OSTI ID: 20719831
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 72, Issue 19; Other Information: DOI: 10.1103/PhysRevB.72.195334; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
CADMIUM SELENIDES
CORRELATIONS
CRYSTAL GROWTH
INTERFACES
LAYERS
QUANTUM DOTS
SEMICONDUCTOR MATERIALS
SMALL ANGLE SCATTERING
SPACE
STACKING FAULTS
STRAINS
THICKNESS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ZINC SELENIDES
ZINC SULFIDES