DOI | Resolve DOI: https://doi.org/10.1021/nl400570p |
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Author | Search for: Wolf, O.; Search for: Dasog, M.; Search for: Yang, Z.; Search for: Balberg, I.; Search for: Veinot, J. G. C.1; Search for: Millo, O. |
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Affiliation | - National Research Council of Canada. Security and Disruptive Technologies
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Format | Text, Article |
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Subject | Band gap variation; Capping ligands; Electronic levels; Quantum confinement effects; scanning-tunneling-spectroscopy; Silicon nanocrystals; surface-doping; Tunneling spectra; Charge transfer; Energy gap; Ligands; Nanocrystals; Photoluminescence; Quantum confinement; Scanning; Scanning tunneling microscopy; Spectroscopy; Silicon |
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Abstract | We have applied scanning tunneling spectroscopy in studies of the electronic level structure of surface-functionalized colloidal Si nanocrystals (Si-NCs) as a function of their size for various capping ligands. The energy gaps extracted from the tunneling spectra increase with decreasing NC size, manifesting the effect of quantum confinement. This is consistent with the blueshift revealed by photoluminescence (PL) from dodecene functionalized Si-NCs. The tunneling spectra measured on NCs functionalized with NH 4Br or allylamine show band-edge shifts toward higher energies, akin to p-type doping. This behavior can be accounted for by the combined contributions of the ligands' dipole moments and charge transfer between a Si-NC and its surface groups. Concomitantly, size-independent PL spectra, which cannot be associated with NC band gap variations, were observed for the latter Si-NCs. © 2013 American Chemical Society. |
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Publication date | 2013-05-10 |
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In | |
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Language | English |
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Peer reviewed | Yes |
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NPARC number | 21271837 |
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Export citation | Export as RIS |
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Report a correction | Report a correction (opens in a new tab) |
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Record identifier | d6c0940d-0c97-437c-a62a-4f624ba4e8f9 |
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Record created | 2014-04-23 |
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Record modified | 2020-04-22 |
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