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Title: Optical properties of individual site-controlled Ge quantum dots

We report photoluminescence (PL) experiments on individual SiGe quantum dots (QDs) that were epitaxially grown in a site-controlled fashion on pre-patterned Si(001) substrates. We demonstrate that the PL line-widths of single QDs decrease with excitation power to about 16 meV, a value that is much narrower than any of the previously reported PL signals in the SiGe/Si heterosystem. At low temperatures, the PL-intensity becomes limited by a 25 meV high potential-barrier between the QDs and the surrounding Ge wetting layer (WL). This barrier impedes QD filling from the WL which collects and traps most of the optically excited holes in this type-II heterosystem.
Authors:
 [1] ;  [2] ;  [2] ;  [1] ;  [2] ;  [3] ;  [4] ; ;  [1] ;  [5] ;  [2]
  1. Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz (Austria)
  2. (Germany)
  3. Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)
  4. (Japan)
  5. Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, Dresden 01069 (Germany)
Publication Date:
OSTI Identifier:
22483088
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 25; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EPITAXY; EXCITATION; GERMANIUM SILICIDES; LAYERS; LINE WIDTHS; MEV RANGE 10-100; OPTICAL PROPERTIES; PHOTOLUMINESCENCE; POTENTIALS; QUANTUM DOTS; SIGNALS; SUBSTRATES; TRAPS