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Composition and size-dependent extinction coefficient of colloidal PbSe quantum dots

Iwan Moreels (UGent) , Karel Lambert (UGent) , David De Muynck (UGent) , Frank Vanhaecke (UGent) , Dirk Poelman (UGent) , José Martins (UGent) , G ALLAN and Zeger Hens (UGent)
(2007) CHEMISTRY OF MATERIALS. 19(25). p.6101-6106
Author
Organization
Abstract
Inductively coupled plasma mass spectrometry (ICP-MS) was combined with UV-vis-NIR spectrophotometry and transmission electron microscopy to determine the nanocrystal composition and molar extinction coefficient epsilon of colloidal PbSe quantum dot (Q-PbSe) Suspensions. The ICP-MS results show a nonstoichiometric Pb/Se ratio, with a systematic excess of lead for all samples studied. The observed ratio is consistent with a faceted spherical Q-PbSe model, composed of a quasi stoichiometric Q-PbSe core terminated by a Ph surface shell. At high photon energies, we find that c scales with the nanocrystal volume, irrespective of the Q-PbSe size. From E, we calculated a size-independent absorption coefficient. Its value is in good agreement with the theoretical value for bulk PbSe. At the band gap, c is size-dependent. The resulting absorption coefficient increases quadratically with decreasing Q-PbSe size. Calculations of the oscillator strength of the first optical transition are in good agreement with theoretical tight binding calculations, showing that the oscillator strength increases linearly with Q-PbSe size.
Keywords
ABSORPTION CROSS-SECTION, OPTICAL-PROPERTIES, NANOCRYSTALS, CDSE, CDTE

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Chicago
Moreels, Iwan, Karel Lambert, David De Muynck, Frank Vanhaecke, Dirk Poelman, José Martins, G ALLAN, and Zeger Hens. 2007. “Composition and Size-dependent Extinction Coefficient of Colloidal PbSe Quantum Dots.” Chemistry of Materials 19 (25): 6101–6106.
APA
Moreels, I., Lambert, K., De Muynck, D., Vanhaecke, F., Poelman, D., Martins, J., ALLAN, G., et al. (2007). Composition and size-dependent extinction coefficient of colloidal PbSe quantum dots. CHEMISTRY OF MATERIALS, 19(25), 6101–6106.
Vancouver
1.
Moreels I, Lambert K, De Muynck D, Vanhaecke F, Poelman D, Martins J, et al. Composition and size-dependent extinction coefficient of colloidal PbSe quantum dots. CHEMISTRY OF MATERIALS. 2007;19(25):6101–6.
MLA
Moreels, Iwan, Karel Lambert, David De Muynck, et al. “Composition and Size-dependent Extinction Coefficient of Colloidal PbSe Quantum Dots.” CHEMISTRY OF MATERIALS 19.25 (2007): 6101–6106. Print.
@article{424688,
  abstract     = {Inductively coupled plasma mass spectrometry (ICP-MS) was combined with UV-vis-NIR spectrophotometry and transmission electron microscopy to determine the nanocrystal composition and molar extinction coefficient epsilon of colloidal PbSe quantum dot (Q-PbSe) Suspensions. The ICP-MS results show a nonstoichiometric Pb/Se ratio, with a systematic excess of lead for all samples studied. The observed ratio is consistent with a faceted spherical Q-PbSe model, composed of a quasi stoichiometric Q-PbSe core terminated by a Ph surface shell. At high photon energies, we find that c scales with the nanocrystal volume, irrespective of the Q-PbSe size. From E, we calculated a size-independent absorption coefficient. Its value is in good agreement with the theoretical value for bulk PbSe. At the band gap, c is size-dependent. The resulting absorption coefficient increases quadratically with decreasing Q-PbSe size. Calculations of the oscillator strength of the first optical transition are in good agreement with theoretical tight binding calculations, showing that the oscillator strength increases linearly with Q-PbSe size.},
  author       = {Moreels, Iwan and Lambert, Karel and De Muynck, David and Vanhaecke, Frank and Poelman, Dirk and Martins, Jos{\'e} and ALLAN, G and Hens, Zeger},
  issn         = {0897-4756},
  journal      = {CHEMISTRY OF MATERIALS},
  language     = {eng},
  number       = {25},
  pages        = {6101--6106},
  title        = {Composition and size-dependent extinction coefficient of colloidal PbSe quantum dots},
  volume       = {19},
  year         = {2007},
}

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