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

Journal Article · Mon Nov 03 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4901180· OSTI ID:22391906

Webber, D.; Yildirim, M.; Hacquebard, L.; March, S.; Mathew, R.; Gamouras, A.; Hall, K. C. ^[1]; Liu, X.; Dobrowolska, M.; Furdyna, J. K. ^[2]

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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)

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.

• OSTI ID: 22391906
• Journal Information: Applied Physics Letters, Vol. 105, Issue 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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