Anisotropic photoconductivity of InGaAs quantum dot chains measured by terahertz pulse spectroscopy

Journal Article · Mon Oct 25 00:00:00 EDT 2004 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1807959· OSTI ID:20634377

Cooke, D G; Hegmann, F A; Mazur, Yu I; Ma, W Q; Wang, X; Wang, Z M; Salamo, G J; Xiao, M; Mishima, T D; Johnson, M B ^[1]

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1. Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)

We report results of time-resolved terahertz (THz) pulse spectroscopy experiments on laterally ordered chains of self-assembled InGaAs quantum dots photoexcited with 400 nm, 100 fs laser pulses. A large anisotropy in the transient photoconductive response is observed depending on the polarization of the THz probe pulse with respect to the orientation of the dot chains. Fast (3.5-5 ps) and efficient carrier capture into the dots and one-dimensional wetting layers underneath the dot chains is observed below 90 K. At higher temperatures, thermionic emission into the two-dimensional wetting layers and barriers becomes significant and the anisotropy in the photoconductive signal is reduced.

• OSTI ID: 20634377
• Journal Information: Applied Physics Letters, Vol. 85, Issue 17; Other Information: DOI: 10.1063/1.1807959; (c) 2004 American Institute of Physics; 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
ANISOTROPY
GALLIUM ARSENIDES
HOLES
INDIUM COMPOUNDS
LASERS
LAYERS
PHOTOCONDUCTIVITY
POLARIZATION
QUANTUM DOTS
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
THERMIONIC EMISSION
THZ RANGE
TIME RESOLUTION