Optimization of Band Structure and Quantum-Size-Effect Tuning for Two-Photon Absorption Enhancement in Quantum Dots
Abbreviated Journal Title
Nano Lett.
Keywords
Nonlinear optics; two-photon absorption; quantum dots; nonlinear; spectroscopy; lead salt; band structure; OPTICAL NONLINEARITIES; SEMICONDUCTOR MICROCRYSTALLITES; MEDIATED; ENHANCEMENT; EXCITATION; PBS; NANOCRYSTALS; SPECTROSCOPY; DYES; Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience &; Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter
Abstract
The two-photon absorption, 2PA, cross sections of PbS quantum dots, QDs, are theoretically and experimentally investigated and are shown to be enhanced with increasing quantum confinement. This is in contrast to our previous results for CdSe and CdTe QDs where the reduced density of states dominated and resulted in a decrease in 2PA with a decrease in QD size. Qualitatively this trend can be understood by the highly symmetric distribution of conduction and valence band states in PbS that results in an accumulation of allowed 2PA transitions in certain spectral regions. We also measure the frequency nondegenerate 2PA cross sections that are up to five times larger than for the degenerate case. We use a k.p four-band envelope function formalism to model the increasing trend of the two-photon cross sections due to quantum confinement and also due to resonance enhancement in the nondegenerate case.
Journal Title
Nano Letters
Volume
11
Issue/Number
3
Publication Date
1-1-2011
Document Type
Article
DOI Link
Language
English
First Page
1227
Last Page
1231
WOS Identifier
ISSN
1530-6984
Recommended Citation
"Optimization of Band Structure and Quantum-Size-Effect Tuning for Two-Photon Absorption Enhancement in Quantum Dots" (2011). Faculty Bibliography 2010s. 1740.
https://stars.library.ucf.edu/facultybib2010/1740
Comments
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