Challenging the limits of near-infrared emission by all-organic fluorophores (R-11611)

Over the last decade, electroluminescence from organic chromophores has evolved into a flourishing industry. Fundamental materials and device research efforts have been key to this commercial success. The optoelectronic properties of organic semiconductors match very well to the requirements of light emission in the visible range. However, developing materials affording efficient near-infrared (NIR) emission is considerably less straightforward. In general, narrow-gap organic emitters show a significantly lower luminescence efficiency as a result of aggregation quenching and the energy-gap law. Moreover, the use of (toxic) heavy metals to achieve triplet leveraging should be avoided, certainly when aiming at in vivo applications. In this project, the fundamental challenge to achieve efficient NIR emission from all-organic π-conjugated systems is tackled by judicious - computationally guided - design and synthesis of original donor-acceptor type chromophores affording high photoand electroluminescence quantum yields through either classical fluorescence, thermally activated delayed fluorescence or a combination of both. All novel fluorophores will be thoroughly characterized from a structural and photophysical point of view and then implemented in state-of-the-art organic light-emitting diodes (OLEDs) to afford detailed structure-property relations. As such, we aim at a substantial materials science contribution to the emergence of NIR-OLEDs for high-end applications.

Keywords:OLED, organic light-emitting diodes, thermally activated delayed fluorescence

Disciplines:Optical properties of materials, Organic chemical synthesis, Molecular and organic electronics