Mastodawn

🔎What are #perovskites and #quantumdots?

Prof. #Photophysics and #Optoelectronics Maria Antonietta Loi uses these minerals and 'super atoms' to create new materials for #solarcells and LED lights - materials that turn light into electricity, or vice versa.💡

🧪 #SciComm #Science #engineering #technology #research #physics #electronic #scientistsOnMastodon @universityofgroningen

Beilstein-Institut Oct 1

Thanks to all our speakers and participants for making the Beilstein Organic Chemistry Symposium “Organic #semiconductor materials: Challenges and opportunities” an amazing event!

Special thanks 🙏 to our scientific organizers Stefan Braese, @KIT_Karlsruhe, and Jessica Wade, @jesswade, Imperial College London.

The first pics 📷 of the photo gallery are online 🔗 https://tinyurl.com/b68678a7

#BeilsteinSemiconductors2025 #photophysics #optoelectronics

Beilstein-Institut Sep 11

Save the date and join the FREE livestream 🎥 of the Beilstein Organic Chemistry Symposium “Organic #semiconductor materials: Challenges and opportunities” in Frankfurt/Main, 🇩🇪, 📅 Sept. 23–25, 2025.

The scientific organizers Stefan Braese, @KIT_Karlsruhe, and Jessica Wade, @jesswade, Imperial College London, are looking forward to your participation.

🔗 https://tinyurl.com/2ap8bt7j

#BeilsteinSemiconductors2025 #photophysics #optoelectronics

Maciej Spiegel Sep 9

New preprint on ChemRxiv! 🚀
It shows how aggregation suppresses internal conversion and enables triplet formation in hypericin assemblies.

🔗 https://doi.org/10.26434/chemrxiv-2025-5bcs5

#Chemistry #Photophysics #Photochemistry #OpenScience

Aggregation Suppresses Internal Conversion and Enhances Triplet Yield in π-Rich Dyes by Vibronic Coupling Control: A Case Study of Hypericin Supramolecular Assembly

Hypericin, a naturally occurring anthraquinone dye, displays unusually high triplet quantum yields despite its weak spin–orbit coupling and strong propensity to aggregate in solution—an apparent contradiction to conventional photophysical models. Using quantum chemical calculations and long-timescale molecular dynamics simulations, we show that supramolecular aggregation, particularly dimer formation, profoundly alters excited-state dynamics. Aggregation suppresses internal conversion by reducing nonadiabatic coupling and damping low-frequency vibrational modes, thereby prolonging excited-state lifetimes. Concurrently, excitonic interactions and energetic reordering of excited states increase the density of accessible triplet levels, enabling efficient intersystem crossing through energetically favorable pathways—even in the absence of enhanced spin–orbit coupling. These findings reconcile previously unexplained discrepancies between theoretical predictions and experimental observations for hypericin, and provide a broadly applicable mechanistic framework for enhancing triplet generation in heavy-atom-free photosensitizers through supramolecular design.

ChemRxiv