Intermolecular H-bond promoting diphenylsulfone derivatives for aggregation-induced blue-shifted thermally activated delayed fluorescence

Abstract

Organic light-emitting diodes (OLEDs) rely on efficient emitters, yet the development of high-performance blue thermally activated delayed fluorescence (TADF) materials remains challenging. Herein, two diphenylsulfone (DPS) derivatives, HO-DPS-DMAC and F-DPS-DMAC, with 9,10-dihydro-9,9-dimethylacridine (DMAC) donor and H-bond formation substituents hydroxyl (OH) and fluorine (F), respectively, are presented. These targeted modifications fine-tuned the HOMO–LUMO energy levels, minimized the singlet–triplet gap (ΔE_ST), and promoted aggregation-induced blue-shifted emission with enhanced photoluminescence quantum yields (PLQYs). Notably, benefiting from the rigidity induced by H-bonds (O⋯H and F⋯H), the crystals of HO-DPS-DMAC and F-DPS-DMAC realized efficient deep-blue TADF emissions peaking at 452 nm (Φ_F = 31.20%) and 461 nm (Φ_F = 36.68%), respectively, with rapid reverse intersystem crossing (>10⁶ s⁻¹). Non-doped OLEDs based on HO-DPS-DMAC and F-DPS-DMAC achieved blue emission, showing EL peaking at 466 nm with CIE (0.19, 0.30) and 481 nm with CIE (0.20, 0.31), respectively. This work provided a viable design strategy for efficient blue emitters in OLEDs applications.