Highly efficient deep-blue OLEDs with CIE closely approaches Rec.2020 standard based on an acridine-naphthalene hybrid fluorophore

9,9-Dimethyl-9,10-dihydroacridine (DMAC) and naphthalene are fused to produce a chromophore 12,12Dimethyl-7,12-dihydrobenzo[a] acridine (DMBA). Based on DMBA, two emitters, 12,12-dimethyl-7-phenyl-7,12dihydrobenzo[a]acridine (BACH) and 3-fluoro-12,12-dimethyl-7-phenyl-7,12-dihydrobenzo[a]acridine (BACF), were designed and synthesized. Thanks to the planar structure and weak electron donating ability of DMBA, these two emitters exhibit deep-blue emissions with photoluminescence (PL) spectra peaks (lambda PLs) of 402-422 nm in solutions and doped films. The non-doped devices based on BACH and BACF present excellent deep-blue electroluminescence (EL) emission with spectra peaks (lambda ELs) of 428 and 427 nm, maximum external quantum efficiencies (EQEs) of 6.09% and 5.99%, respectively. Notably, the CIE coordinates of these non-doped devices closely approach the Rec.2020 standard (0.131, 0.046).