Applications of Ultrafast Terahertz Pulses for Intra-ExcitonicSpectroscopy of Quasi-2D Electron-Hole Gases [electronic resource]
Low-dimensional Semiconductors Terahertz Spectroscopy Excitonsultrafast Processes.
Saved in:
| Online Access: |
Online Access |
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| Corporate Author: | |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Berkeley, Calif. : Oak Ridge, Tenn. :
Lawrence Berkeley National Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
2006.
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| Subjects: |
| Summary: | Low-dimensional Semiconductors Terahertz Spectroscopy Excitonsultrafast Processes. |
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| Abstract: | Excitons are of fundamental interest and of importance foropto-electronic applications of bulk and nano-structured semiconductors.This paper discusses the utilization of ultrafast terahertz (THz) pulsesfor the study of characteristic low-energy excitations of photoexcitedquasi 2D electron-hole (e-h) gases. Optical-pump THz-probe spectroscopyat 250-kHz repetition rate is employed to detect characteristic THzsignatures of excitons and unbound e-h pairs in GaAs quantum wells.Exciton and free-carrier densities are extracted from the data using atwo-component model. We report the detailed THz response and pairdensities for different photoexcitation energies resonant to heavy-holeexcitons, light-hole excitons, or the continuum of unbound pairs. Suchexperiments can provide quantitative insights into wavelength, time, andtemperature dependence of the low-energy response and composition ofoptically excited e-h gases in low-dimensionalsemiconductors. |
| Item Description: | Published through the Information Bridge: DOE Scientific and Technical Information. 09/02/2006. "lbnl--61752" ": KC0202020" Journal of Nanoelectronics and Optoelectronics 2 1 FT. Journal Publication Date: 04/2007. Chemla, D.S.; Kaindl, Robert A.; Carnahan, Marc A.; Hagele, Daniel. USDOE Director. Office of Science. Basic EnergySciences. |