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Title: Observation of the exciton and Urbach band tail in low-temperature-grown GaAs using four-wave mixing spectroscopy

Four-wave mixing (FWM) spectroscopy reveals clear signatures associated with the exciton, free carrier inter-band transitions, and the Urbach band tail in low-temperature-grown GaAs, providing a direct measure of the effective band gap as well as insight into the influence of disorder on the electronic structure. The ability to detect (and resolve) these contributions, in contrast to linear spectroscopy, is due to an enhanced sensitivity of FWM to the optical joint density of states and to many-body effects. Our experiments demonstrate the power of FWM for studying the near-band-edge optical properties and coherent carrier dynamics in low-temperature-grown semiconductors.
Authors:
; ; ; ; ; ;  [1] ; ; ;  [2]
  1. Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada)
  2. Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
Publication Date:
OSTI Identifier:
22391906
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DENSITY OF STATES; ELECTRONIC STRUCTURE; FREQUENCY MIXING; GALLIUM ARSENIDES; MANY-BODY PROBLEM; OPTICAL PROPERTIES; SEMICONDUCTOR MATERIALS; SPECTROSCOPY