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Title: Indirect and direct optical transitions in In{sub 0.5}Ga{sub 0.5}As/GaP quantum dots

We present a study of self-assembled In{sub 0.5}Ga{sub 0.5}As quantum dots on GaP(001) surfaces linking growth parameters with structural, optical, and electronic properties. Quantum dot densities from 5.0 × 10{sup 7} cm{sup −2} to 1.5 × 10{sup 11} cm{sup −2} are achieved. A ripening process during a growth interruption after In{sub 0.5}Ga{sub 0.5}As deposition is used to vary the quantum dot size. The main focus of this work lies on the nature of optical transitions which can be switched from low-efficient indirect to high-efficient direct ones through improved strain relief of the quantum dots by different cap layers.
Authors:
; ; ; ;  [1] ;  [2] ;  [3]
  1. Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany)
  2. Zentraleinrichtung Elektronenmikroskopie, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)
  3. Institut für Optik und Atomare Physik, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)
Publication Date:
OSTI Identifier:
22258590
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CRYSTAL GROWTH; DEPOSITION; GALLIUM PHOSPHIDES; QUANTUM DOTS