TITLE

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

AUTHOR(S)
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.
PUB. DATE
October 2004
SOURCE
Applied Physics Letters;10/25/2004, Vol. 85 Issue 17, p3839
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
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.
ACCESSION #
14909810

 

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