Benzene[g]furan[2,3-B]quinoxaline-based red fluorescent material for non-doped organic light-emitting devices with low efficiency roll-off

New emitters with deeply red emission and slow efficiency roll-off in non-doped organic light-emitting diodes (OLEDs) are highly expected. In this work, we used our recently developed 2-phenylbenzo[g]furo[2,3-b]-quinoxaline as the acceptor (A) and triphenylamine (TPA) as the donor (D), synthesized a D-A type red emitter, TPA-PFQ. The TPA-PFQ presented a high quantum yields of 88.03% in toluene solution. Using it as emitter, the non-doped OLEDs showed a saturated red emission with a peak of 620 nm and a maximum luminance of 11190 cd m⁻². Moreover, the non-doped OLEDs presented a maximum EQE of 2.09% (2.47 cd A^-1) at 100 cd m⁻², and remained 2.0% (2.40 cd A^-1) at 1000 cd m⁻², 2.03% (2.49 cd A^-1) at 5000 cd m⁻², only 2.9% efficiency roll-off with the luminance changed from 100 cd m⁻² to 5000 cd m⁻². Our experiments demonstrated benzo[g]furo[2,3-b]quinoxaline skeleton could serve as a promising acceptor unit for constructing deep red emitters.