A new organic molecule breaks records for phosphorescence efficiency and paves the way for rare metal-free applications

A research team led by Osaka University has discovered that a new organic molecule, thienyl diketone, exhibits highly efficient phosphorescence. It achieved phosphorescence more than ten times faster than traditional materials, allowing the team to elucidate this mechanism.

The work is published in a journal Chemical science.

Phosphorescence is a valuable optical feature used in applications such as organic EL displays (OLEDs) and cancer diagnostics. Until now, achieving highly efficient phosphorescence without the use of rare metals such as iridium and platinum has been a significant challenge. Phosphorescence, which occurs when a molecule goes from a high-energy state to a low-energy state, often competes with non-radiative processes where the molecule loses energy as heat.

This competition can lead to slow phosphorescence and lower efficiency. While previous research has shown that incorporating certain structural elements into organic molecules could speed up phosphorescence, these efforts have not matched the speed and efficiency of rare metal-based materials.

The research team’s breakthrough with the new organic molecule thienyl diketone represents a significant advance in this field. Yosuke Tani, lead author of the study, commented, “We discovered this molecule by chance and initially did not understand why it performed so well. However, as our research progressed, we began to put the pieces together and deepen our understanding.”

“Our research has led to a clearer understanding of the mechanism behind the performance of this molecule than any previous organic phosphorescent material,” explains Dr. Thaw. “However, we believe there is still more to explore and are excited about its potential applications.”

This research provides new design guidelines for the development of organic phosphorescent materials that do not rely on rare metals and offers the potential to outperform and replace these materials in a variety of applications. The findings promise significant advances in the fields of OLED, lighting and medical diagnostics, among others.