New organic molecule breaks records in phosphorescence efficiency, paving the way for rare-metal-free applications

A research team led by Osaka University found that the new organic molecule thienyldiketone exhibits high-efficiency phosphorescence. It achieved phosphorescence more than ten times faster than traditional materials, allowing the team to clarify this mechanism.

The article was published in the magazine Chemical science.

Phosphorescence is a valuable optical function used in applications such as organic EL displays (OLEDs) and cancer diagnostics. Until now, achieving high-efficiency phosphorescence without using rare metals such as iridium and platinum has been a significant challenge. Phosphorescence, which occurs when a molecule transitions from a high-energy state to a low-energy state, often competes with nonradiative processes in which the molecule loses energy as heat.

This competition can lead to slow phosphorescence and lower efficiency. Although previous research suggested that incorporating certain structural elements into organic molecules could accelerate 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 thienyldiketone represents a significant advance in the field. Yosuke Tani, senior author of the study, noted, “We discovered this molecule by chance and initially didn’t understand why it showed such superior performance. However, as our research progressed, we began to put the pieces together and deepened 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,” Dr. Tani explains. “Nevertheless, we believe there is still much to be discovered and we are excited about its potential applications.”

This research provides new design guidelines for developing organic phosphorescent materials that do not rely on rare metals, which have the potential to outperform and replace these materials in various applications. The findings promise significant advances in OLEDs, lighting, and medical diagnostics, among others.