Deep‐Blue Hot Exciton Emitter Based on Chrysene Core for High‐Efficiency Non‐Doped OLEDs with EQE > 13% and CIEy < 0.05, as Well as Host‐Sensitized OLEDs

Abstract Developing high‐efficiency deep‐blue “hot exciton” emitters that meet the color‐gamut requirements of BT.2020 standards remains a significant challenge for organic light‐emitting diodes (OLEDs). Traditional hot exciton materials, primarily based on anthracene and pyrene cores, suffer from narrow bandgaps and poor luminescence efficiencies in solid films. Consequently, non‐doped devices typically exhibit Commission Internationale de l'éclairage (CIE) coordinates of y > 0.10 with maximum external quantum efficiency (EQE _max ) ≤ 10%. Herein, chrysene is innovatively introduced as the construction core for hot exciton materials and yields two novel deep‐blue emitters, p CzChCy and o CzChCy. Leveraging the wide bandgap and twisted conformation of the chrysene core, both emitters exhibit deep‐blue emissions (≈430 nm) with remarkably high luminescence efficiencies (>80%) even in neat films. Photophysical measurements further confirmed the hot exciton characteristics of these two materials. In electroluminescence, the non‐doped OLED based on p CzChCy ( o CzChCy) achieved a record‐high EQE _max of 13.3% (12.0%) with CIEy = 0.049 (0.037), closely approaching the BT.2020 standard. Given the deep‐blue emission of chrysene‐based emitters, they can also serve as sensitizing host materials. The corresponding binary doped devices adopting organoboron‐nitrogen‐based fluorophore as guest enable blue OLEDs with EQE _max >16% and full width at half maximum (FWHM) of only 17 nm.