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

Abstract

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.

Authors:
; ; ; ; ; ; ;  [1];  [2];  [3]
  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)
Publication Date:
OSTI Identifier:
20719831
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 72; Journal Issue: 19; Other Information: DOI: 10.1103/PhysRevB.72.195334; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Schmidt, Th., Roventa, E., Clausen, T., Flege, J. I., Alexe, G., Rosenauer, A., Hommel, D., Falta, J., Bernstorff, S., and Kuebel, C.. Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach. United States: N. p., 2005. Web. doi:10.1103/PhysRevB.72.195334.
Schmidt, Th., Roventa, E., Clausen, T., Flege, J. I., Alexe, G., Rosenauer, A., Hommel, D., Falta, J., Bernstorff, S., & Kuebel, C.. Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach. United States. doi:10.1103/PhysRevB.72.195334.
Schmidt, Th., Roventa, E., Clausen, T., Flege, J. I., Alexe, G., Rosenauer, A., Hommel, D., Falta, J., Bernstorff, S., and Kuebel, C.. Tue . "Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach". United States. doi:10.1103/PhysRevB.72.195334.
@article{osti_20719831,
title = {Ordering mechanism of stacked CdSe/ZnS{sub x}Se{sub 1-x} quantum dots: A combined reciprocal-space and real-space approach},
author = {Schmidt, Th. and Roventa, E. and Clausen, T. and Flege, J. I. and Alexe, G. and Rosenauer, A. and Hommel, D. and Falta, J. and Bernstorff, S. and Kuebel, C.},
abstractNote = {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.},
doi = {10.1103/PhysRevB.72.195334},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 19,
volume = 72,
place = {United States},
year = {Tue Nov 15 00:00:00 EST 2005},
month = {Tue Nov 15 00:00:00 EST 2005}
}
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