| Autor: |
Mandal, Haraprasad, Ogunyemi, Olusayo J., Nicholson, Jake L., Orr, Meghan E., Lalisse, Remy F., Rentería-Gómez, Ángel, Gogoi, Achyut R., Gutierrez, Osvaldo, Michaudel, Quentin, Goodson, Theodore |
| Zdroj: |
The Journal of Physical Chemistry - Part C; February 2024, Vol. 128 Issue: 6 p2518-2528, 11p |
| Abstrakt: |
Poly(p-phenylenevinylene) (PPV) is a staple of the family of conjugated polymers with desirable optoelectronic properties for applications including light-emitting diodes (LEDs) and photovoltaic devices. Although the significant impact of olefin geometry on the steady-state optical properties of PPVs has been extensively studied, PPVs with precise stereochemistry have yet to be investigated using nonlinear optical spectroscopy for quantum sensing, as well as light harvesting for biological applications. Herein, we report our investigation of the influence of olefin stereochemistry on both linear and nonlinear optical properties through the synthesis of all-cisand all-transPPV copolymers. We performed two-photon absorption (TPA) using a classical and entangled light source and compared both classical TPA and entangled two-photon absorption (ETPA) cross sections of these stereodefined PPVs. Whereas the TPA cross section of the all-transPPV was expectedly higher than that of all-cisPPV, presumably because of the larger transition dipole moment, the opposite trend was measured via ETPA, with the all-cisPPV exhibiting the highest ETPA cross section. DFT calculations suggest that this difference might stem from the interaction of entangled photons with lower-lying electronic states in the all-cisPPV variant. Additionally, we explored the photoinduced processes for both cisand transPPVs through time-resolved fluorescence upconversion and femtosecond transient absorption techniques. This study revealed that the sensitivity of PPVs in two-photon absorption varies with classical versus quantum light and can be modulated through the control of the geometry of the repeating alkenes, which is a key stepping stone toward their use in quantum sensing, bioimaging, and the design of polymer-based light-harvesting systems. |
| Databáze: |
Supplemental Index |
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