Researchers use π-Electron reorganization to achieve the highest-efficiency narrowband red fluorescence OLED emitters

Researchers from Sichuan University have used π-electron delocalization of classic PAHs molecules, through skeleton reconstruction, to design red fluorescence narrowband OLED emitters that offer the highest efficiency to date (24.2% EQE).

The researchers explain that their material design strategy enables the controllable transition of aromaticity from global delocalization to local localization, restricts long-range π-electron delocalization, suppresses excited-state vibrational coupling, and thus promises intrinsically narrow-spectrum emission materials.

The researchers designed several new  PAHS molecules, utilizing the new strategy, and used these in a phosphorescence-sensitized fluorescence (PSF OLED) platform. With FWHM ranging from 26 nm to 28 nm, and EQE ranging from 20.2% to 24.2%, these finding represent the highest EQE of such red emitters to date, with the narrowest FWHM among all reported BT.2020-compliant red OLEDs.