Synthesis, photoluminescence and electroluminescence properties of a new blue emitter containing carbazole, acridine and diphenyl sulfone units

The development of luminescent materials with both thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) characteristics is conducive to the preparation of high-efficiency organic light-emitting diodes (OLEDs). Herein, a new emitter, namely 10-(4-((3,5-di(9H-carbazol-9-yl)phenyl)sulfonyl)phenyl)-9,9-dimethyl-9, 10-dihydroacridine (CZ-DPS-DMAC), bearing carbazole as the skeleton, 9,9-dimethyl-9,10-dihydroacridine as the electron donor unit and diphenyl sulfone as the electron acceptor group was designed and synthesized. The structure was characterized by 1H NMR, 13C NMR and mass spectrometry. The optical, electrical, and thermal properties were studied comprehensively. The results show that CZ-DPS-DMAC excellent thermal stabilities, stable redox properties, obvious AIE and TADF characteristics. It also exhibits high photoluminescence quantum yield of 54% in powder. On this basis, non-doped (A) and doped (B, C) OLEDs with CZ-DPS-DMAC and different concentrations doped into the DPEPO host as light-emitting layers were manufactured. Electroluminescence investigation shows that device A displays a blue emission with maximum emission peak (λmax) of 483 nm, a maximum current efficiency (CEmax) of 25.42 cd A−1, a maximum power efficiency (PEmax) of 30.70 lm W−1, a maximum luminance (Lmax) of 2322 cd m−2 and a maximum external quantum efficiency (EQEmax) of 12.00%. The device B in which the guest doped with 10% concentration in the host material is the light-emitting layer exhibits good performance with a λmax of 477 nm, a CEmax of 23.40 cd A−1, a PEmax of 20.28 lm W−1, a Lmax of 1753 cd m−2 and an EQEmax of 14.27%. The excellent performance demonstrated by CZ-DPS-DMAC suggests that it is a promising candidate for fabricating OLEDs with high efficiency.