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Exciton recombination dynamics in CdSe nanowires: Bimolecular to three-carrier Auger kinetics

Robel, Istvan and Bunker, Bruce A. and Kamat, Prashant V. and Kuno, Masaru (2006) Exciton recombination dynamics in CdSe nanowires: Bimolecular to three-carrier Auger kinetics. NANO LETTERS, 6 (7). pp. 1344-1349.

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Official URL: http://dx.doi.org/10.1021/nl060199z

Abstract

Ultrafast relaxation dynamics of charge carriers in CdSe quantum wires with diameters between 6 and 8 nm are studied as a function of carrier density. At high electron-hole pair densities above 10(19) cm(-3) the dominant process for carrier cooling is the ``bimolecular'' Auger recombination of one-dimensional (1D) excitons. However, below this excitation level an unexpected transition from a bimolecular (exciton-exciton) to a three-carrier Auger relaxation mechanism occurs. Thus, depending on excitation intensity, electron-hole pair relaxation dynamics in the nanowires exhibit either 1D or 0D ( quantum dot) character. This dual nature of the recovery kinetics defines an optimal intensity for achieving optical gain in solution-grown nanowires given the different carrier-density-dependent scaling of relaxation rates in either regime.

Item Type:Article
Subjects:Physical Science > Nanoelectronics
Material Science > Nanostructured materials
ID Code:3754
Deposited By:SPI
Deposited On:26 Jan 2009 11:59
Last Modified:26 Jan 2009 11:59

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