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Title: Highly polarized emission from electrical spin injection into an InGaAs quantum well with free carriers

We report on a highly polarized emission from InGaAs/GaAs-quantum well light-emitting diodes in which we inject spin-polarized electrons from an Fe/Schottky contact. The emission spectra consist of the e{sub 1}h{sub 1} free exciton (FX) and a feature 12 meV below FX attributed to band-to-band (BB) recombination. The FX exhibits a maximum circular polarization of 22%, with a magnetic-field dependence characteristic of spin injection from Fe. The BB emission on the other hand exhibits a polarization that is strongly bias and temperature dependent, with intriguing magnetic-field dependence: The polarization exhibits a maximum of 78% at 2.5 T and 2 K, then decreases linearly with field and reaches −78% at 7 T, attributed to magnetic-field dependent spin relaxation in the presence of excess electrons.
Authors:
;  [1] ;  [2] ;  [3] ; ;  [4]
  1. Naval Research Laboratory, Washington, D.C., 20375 (United States)
  2. Department of Materials Science and Technology, University of Crete, Heraklion Crete 71003 (Greece)
  3. SUNY Buffalo, Buffalo, New York 14260 (United States)
  4. Quantum Theory Group, Emerging Technologies Division, National Research Council, Ottawa K1A0R6 (Canada)
Publication Date:
OSTI Identifier:
22254019
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 21; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ELECTRONS; EMISSION SPECTRA; GALLIUM ARSENIDES; INDIUM ARSENIDES; LIGHT EMITTING DIODES; MAGNETIC FIELDS; QUANTUM WELLS; SPIN; SPIN ORIENTATION; TEMPERATURE DEPENDENCE