skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Controlling Planar and Vertical Ordering in Three-Dimensional (In,Ga)As Quantum Dot Lattices by GaAs Surface Orientation

Abstract

Anisotropic surface diffusion and strain are used to explain the formation of three-dimensional (In,Ga)As quantum dot lattices. The diffusion characteristics of the surface, coupled with the elastic anisotropy of the matrix, provides an excellent opportunity to influence the dot positions. In particular, quantum dots that are laterally organized into long chains or chessboard two-dimensional arrays vertically organized with strict vertical ordering or vertical ordering that is inclined to the sample surface normal are accurately predicted and observed.

Authors:
 [1]; ; ; ;  [2]; ; ;  [3];  [4]
  1. Institut fuer Kristallzuechtung, D-12489 Berlin (Germany)
  2. Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701 (United States)
  3. Institut fuer Physik, Humboldt-Universitaet zu Berlin, D-12489 Berlin (Germany)
  4. Martin-Luther-Universitaet Halle-Wittenberg, D-06120 Halle/Saale (Germany)
Publication Date:
OSTI Identifier:
20778618
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevLett.96.066108; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANISOTROPY; DIFFUSION; GALLIUM ARSENIDES; GRAIN ORIENTATION; INDIUM ARSENIDES; QUANTUM DOTS; STRAINS; THREE-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Schmidbauer, M., Seydmohamadi, Sh., Wang, Zh.M., Mazur, Yu.I., Salamo, G.J., Grigoriev, D., Schaefer, P., Koehler, R., and Hanke, M. Controlling Planar and Vertical Ordering in Three-Dimensional (In,Ga)As Quantum Dot Lattices by GaAs Surface Orientation. United States: N. p., 2006. Web. doi:10.1103/PHYSREVLETT.96.0.
Schmidbauer, M., Seydmohamadi, Sh., Wang, Zh.M., Mazur, Yu.I., Salamo, G.J., Grigoriev, D., Schaefer, P., Koehler, R., & Hanke, M. Controlling Planar and Vertical Ordering in Three-Dimensional (In,Ga)As Quantum Dot Lattices by GaAs Surface Orientation. United States. doi:10.1103/PHYSREVLETT.96.0.
Schmidbauer, M., Seydmohamadi, Sh., Wang, Zh.M., Mazur, Yu.I., Salamo, G.J., Grigoriev, D., Schaefer, P., Koehler, R., and Hanke, M. Fri . "Controlling Planar and Vertical Ordering in Three-Dimensional (In,Ga)As Quantum Dot Lattices by GaAs Surface Orientation". United States. doi:10.1103/PHYSREVLETT.96.0.
@article{osti_20778618,
title = {Controlling Planar and Vertical Ordering in Three-Dimensional (In,Ga)As Quantum Dot Lattices by GaAs Surface Orientation},
author = {Schmidbauer, M. and Seydmohamadi, Sh. and Wang, Zh.M. and Mazur, Yu.I. and Salamo, G.J. and Grigoriev, D. and Schaefer, P. and Koehler, R. and Hanke, M.},
abstractNote = {Anisotropic surface diffusion and strain are used to explain the formation of three-dimensional (In,Ga)As quantum dot lattices. The diffusion characteristics of the surface, coupled with the elastic anisotropy of the matrix, provides an excellent opportunity to influence the dot positions. In particular, quantum dots that are laterally organized into long chains or chessboard two-dimensional arrays vertically organized with strict vertical ordering or vertical ordering that is inclined to the sample surface normal are accurately predicted and observed.},
doi = {10.1103/PHYSREVLETT.96.0},
journal = {Physical Review Letters},
number = 6,
volume = 96,
place = {United States},
year = {Fri Feb 17 00:00:00 EST 2006},
month = {Fri Feb 17 00:00:00 EST 2006}
}
  • We have investigated lateral self-assembling in In{sub 0.4}Ga{sub 0.6}As/GaAs quantum dot (QD) multilayers, which were grown by molecular beam epitaxy on GaAs(100) and (n11)B substrates with n=9,8,7,5,4,3. The lateral self-assembling and the QD size distribution have been studied by atomic force microscopy depending on substrate orientation and the number of periods within the multilayers. The observed two-dimensional ordering can be described by a centered rectangular surface unit cell. Derived autocorrelation functions exhibit the most pronounced lateral QD assembling along the elastically soft directions [1n0]. This can be attributed to elastic interaction, the particular elastic anisotropy of the high index substrates,more » and the minimization of the strain energy.« less
  • In{sub x}Ga{sub 1-x}As/GaAs quantum dots (QDs) were grown by solid source molecular beam epitaxy for indium contents of around 30%, which assures the QD growth in the very low strain limit. The structures were fabricated for a constant nominal In{sub x}Ga{sub 1-x}As layer thickness but varying content (strain) from below to far above the critical thickness conditions, which has allowed to detect the onset of three-dimensional island formation and their evolution with the increasing material amount (for higher In contents the critical thickness for island formation is smaller and hence a larger fraction of the In{sub x}Ga{sub 1-x}As layer ismore » spent on dot formation). In order to investigate the properties of such an uncommon QD system, photoreflectance and photoluminescence, combined with scanning electron microscopy, have been used. Optical transitions connected with the ternary layer have been observed and followed from the lowest content quantum well case through the transformation into three-dimensional islands on the wetting layer (WL) and a coexistence of the QD-related and WL-related transitions. Due to the observation of both heavy hole and light hole related transitions in photoreflectance spectra, the thickness of the wetting layer versus changed indium content could be determined, comparing the experimental data with the results of the effective mass envelope function calculations.« less
  • We have investigated the self-organized, step bunch assisted formation of In{sub 0.19}Ga{sub 0.81}As/GaAs quantum dots in vertical superlattices consisting of one, four, eight, and ten periods. Samples were grown by molecular beam epitaxy on vicinal 2 deg. A and 2 deg. B GaAs(001) substrates. Those with miscut along the [110] (2 deg. B) exclusively show step bunches of an aspect ratio larger than 10 but without the formation of quantum dots. This highly linear pattern is improved during subsequent periods as proved by high resolution x-ray diffraction and grazing incidence diffraction. On the other hand, a miscut along the [110]more » (2 deg. A) initially causes a crosslike pattern of step bunches, which finally becomes a two-dimensional arrangement of individual quantum dots.« less
  • Self-organized surface ordering of (In,Ga)As quantum dots in a GaAs matrix was investigated using stacked multiple quantum dot layers prepared by molecular-beam epitaxy. While one-dimensional chain-like ordering is formed on singular and slightly misorientated GaAs(100) surfaces, we report on two-dimensional square-like ordering that appears on GaAs(n11)B, where n is 7, 5, 4, and 3. Using a technique to control surface diffusion, the different ordering patterns are found to result from the competition between anisotropic surface diffusion and anisotropic elastic matrix, a similar mechanism suggested before by Solomon [Appl. Phys. Lett. 84, 2073 (2004)].
  • Data are presented demonstrating the optically coupled operation of a 3{times}3 two-dimensional array of Al{sub {ital x}}Ga{sub 1{minus}{ital x}}As-GaAs vertical-cavity surface-emitting lasers. Room-temperature threshold current for the array is 90 mA, with the device geometry allowing for light emission from the epitaxial side of the device.