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Title: Quantum confinement in Si and Ge nanostructures: Theory and experiment

The role of quantum confinement (QC) in Si and Ge nanostructures (NSs) including quantum dots, quantum wires, and quantum wells is assessed under a wide variety of fabrication methods in terms of both their structural and optical properties. Structural properties include interface states, defect states in a matrix material, and stress, all of which alter the electronic states and hence the measured optical properties. We demonstrate how variations in the fabrication method lead to differences in the NS properties, where the most relevant parameters for each type of fabrication method are highlighted. Si embedded in, or layered between, SiO{sub 2}, and the role of the sub-oxide interface states embodies much of the discussion. Other matrix materials include Si{sub 3}N{sub 4} and Al{sub 2}O{sub 3}. Si NSs exhibit a complicated optical spectrum, because the coupling between the interface states and the confined carriers manifests with varying magnitude depending on the dimension of confinement. Ge NSs do not produce well-defined luminescence due to confined carriers, because of the strong influence from oxygen vacancy defect states. Variations in Si and Ge NS properties are considered in terms of different theoretical models of QC (effective mass approximation, tight binding method, and pseudopotential method). Formore » each theoretical model, we discuss the treatment of the relevant experimental parameters.« less
Authors:
 [1] ;  [2] ; ;  [3]
  1. Laboratory for Simulation of Physical Systems, Beijing Computational Science Research Centre, Beijing 100084 (China)
  2. National Research Council, Ottawa, Ontario K1A 0R6 (Canada)
  3. Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)
Publication Date:
OSTI Identifier:
22269576
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Reviews; Journal Volume: 1; Journal Issue: 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM OXIDES; EFFECTIVE MASS; FABRICATION; LUMINESCENCE; OPTICAL PROPERTIES; QUANTUM DOTS; QUANTUM WELLS; QUANTUM WIRES; SILICA; SILICON NITRIDES; SILICON OXIDES; SPECTRA; STRESSES