Small organic molecules of the push-pull architecture are rapidly gaining their status in the organic electronics applications. In densely packed molecular films, both intra- and intermolecular interactions play an essential role for the device performance. Here we study two different molecules, a highly symmetric star-shaped one and its newly synthesized single arm analogue, for their photophysical properties. Both chromophores were dissolved in a solid matrix at different concentrations to vary their separation and therefore intermolecular coupling. We show that in both molecules the population relaxation accelerates by more than a factor of 10 at shorter intermolecular distances due to self-quenching thereby reducing the exciton survival time. The transient anisotropy dynamics are also quite similar, with their substantial acceleration at shorter interchromophore distances due to exciton diffusion caused by the Förster-like resonance energy transfer. However, the anisotropy values are noticeably lower for the star-shaped molecule because of intramolecular mixing of different polarization states. Finally, a model is presented that accounts for the observed results.
Evgeniia Salamatova, Oleg V. Kozlov, Yuriy N. Luponosov, Alexander N. Solodukhin, Viktoria Y. Toropynina, Sergei A. Ponomarenko, and Maxim S. Pshenichnikov, "Visualization of molecular excitons diffusion," Proc. SPIE 9923, Physical Chemistry of Interfaces and Nanomaterials XV, 99230K (Presented at SPIE Nanoscience + Engineering: August 29, 2016; Published: 26 September 2016); https://doi.org/10.1117/12.2237620.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the conference proceedings. They include the speaker's narration along with a video recording of the presentation slides and animations. Many conference presentations also include full-text papers. Search and browse our growing collection of more than 12,000 conference presentations, including many plenary and keynote presentations.