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Title: Role of quantum confinement in luminescence efficiency of group IV nanostructures

Experimental results obtained previously for the photoluminescence efficiency (PL{sub eff}) of Ge quantum dots (QDs) are theoretically studied. A log-log plot of PL{sub eff} versus QD diameter (D) resulted in an identical slope for each Ge QD sample only when E{sub G}∼(D{sup 2}+D){sup −1}. We identified that above D ≈ 6.2 nm: E{sub G}∼D{sup −1} due to a changing effective mass (EM), while below D ≈ 4.6 nm: E{sub G}∼D{sup −2} due to electron/hole confinement. We propose that as the QD size is initially reduced, the EM is reduced, which increases the Bohr radius and interface scattering until eventually pure quantum confinement effects dominate at small D.
Authors:
 [1] ; ;  [2] ;  [3] ; ; ; ;  [4] ; ;  [5]
  1. Laboratory for Simulation of Physical Systems, Beijing Computational Science Research Centre, Beijing 100084 (China)
  2. Measurement Science and Standards, National Research Council, Ottawa, Ontario K1A 0R6 (Canada)
  3. Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-760 Fortaleza, Ceará (Brazil)
  4. Institut Matériaux Microélectronique Nanosciences de Provence, UMR CNRS, 6137, Avenue Normandie Niemen, 13397 Marseille Cedex 20 (France)
  5. Laboratoire Chimie de la Matière Condensée de Paris, UMR-7574 UPMC-CNRS, Collège de France, 11, place Marcelin Berthelot, 75231 Paris (France)
Publication Date:
OSTI Identifier:
22275617
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 4; 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; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONFINEMENT; EFFECTIVE MASS; EFFICIENCY; ELECTRONS; GERMANIUM; HOLES; INTERFACES; PHOTOLUMINESCENCE; QUANTUM DOTS; SCATTERING