Design, synthesis, and properties of a novel red asymmetric luminescent material incorporating diphenylfumaronitrile, carbazole and acridine units

Abstract

Herein, a deep red luminescent material BCZ-DBFN-AD containing asymmetric structure with both aggregation-induced emission (AIE) and hot exciton properties has been designed and synthesized through bilateral substitution molecular design strategy by introducing 9,9-dimethyl-9,10-dihydroacridine and carbazole electron donors with rotor effect on both sides of diphenylfumanitrile. The distorted molecular configuration and the introduction of larger rigid electron donors endow BCZ-DBFN-AD obvious AIE properties and high solid-state photoluminescence quantum yield (PLQY). Additionally, the distorted molecular configuration can also reduce the carrier injection barrier, activate the conversion channel from triplet exciton to singlet exciton, effectively take into account the locally excited (LE) state component and charge transfer (CT) state component in the hybrid excited state, and effectively improve the efficiency of the device. The PLQY of BCZ-DBFN-AD in the amorphous thin film is 31 %, and the maximum emission wavelength of the non-doped OLED prepared based on BCZ-DBFN-AD is 672 nm with Commission Internationale de L'Eclairage (CIE) coordinates of (0.64, 0.34). The Lmax, CEmax, PEmax, EQEmax are 2489 cd m−2, 1.01 cd A−1, 0.82 lm W−1, 1.83 %, respectively, the efficiency roll-off is only 3 %, and the exciton utilization rate is 29 %, which exceeds the upper limit of 25 % of traditional fluorescent materials.