Spatial Dependence of the Dipolar Interaction between Quantum Dots and Organic Molecules Probed by Two-Color Sum-Frequency Generation Spectroscopy
| Autor: | Christophe Humbert, Thomas Noblet, Abderrahmane Tadjeddine, Laurent Dreesen |
|---|---|
| Přispěvatelé: | Institut de Chimie Physique (ICP), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Group for Research and Applications in Statistical Physics (GRASP), Université de Liège |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Physics and Astronomy (miscellaneous) General Mathematics Physics::Optics quantum dots 02 engineering and technology sumfrequency generation spectroscopy 010402 general chemistry 01 natural sciences Molecular physics UV-Visible spectroscopy Ultraviolet visible spectroscopy UV–Visible spectroscopy dipole–dipole interaction dipole-dipole interaction Monolayer Computer Science (miscellaneous) Spectroscopy [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] Sum-frequency generation centrosymmetry lcsh:Mathematics Nonlinear optics phenyl derivative lcsh:QA1-939 021001 nanoscience & nanotechnology 0104 chemical sciences non-linear optics sum-frequency generation spectroscopy Chemistry (miscellaneous) Quantum dot Attenuated total reflection [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] 0210 nano-technology Sum frequency generation spectroscopy |
| Zdroj: | Symmetry Symmetry, MDPI, 2021, 13 (2), pp.294. ⟨10.3390/sym13020294⟩ Volume 13 Issue 2 Symmetry, Vol 13, Iss 294, p 294 (2021) |
| ISSN: | 2073-8994 |
| DOI: | 10.3390/sym13020294⟩ |
| Popis: | Given the tunability of their optical properties over the UV–Visible–Near IR spectral range, ligand-capped quantum dots (QDs) are employed for the design of optical biosensors with low detection threshold. Thanks to non-linear optical spectroscopies, the absorption properties of QDs are indeed used to selectively enhance the local vibrational response of molecules located in their vicinity. Previous studies led to assume the existence of a vibroelectronic QD–molecule coupling based on dipolar interaction. However, no systematic study on the strength of this coupling has been performed to date. In order to address this issue, we use non-linear optical Two-Color Sum-Frequency Generation (2C-SFG) spectroscopy to probe thick QD layers deposited on calcium fluoride (CaF2) prisms previously functionalized by a self-assembled monolayer of phenyltriethoxysilane (PhTES) molecules. Here, 2C-SFG is performed in Attenuated Total Reflection (ATR) configuration. By comparing the molecular vibrational enhancement measured for QD–ligand coupling and QD–PhTES coupling, we show that the spatial dependence of the QD–molecule interactions (∼1/r3, with r the QD–molecule distance) is in agreement with the hypothesis of a dipole–dipole interaction. |
| Databáze: | OpenAIRE |
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