Anthracene-Based Bipolar Emitter for High-Performance Deep-Blue Organic Light-Emitting Diodes

Developing high-efficiency deep-blue emitters with exceptional color purity remains a critical challenge for organic light-emitting diodes (OLEDs). In this work, we report the strategic design and synthesis of a novel fluorescent emitter, CAP, by integrating a π-conjugated anthracene core with a 9-phenylcarbazole and 4-methylpyridine framework. Density functional theory simulations reveal that the frontier molecular orbital distributions for both S₀ → S₁ and S₀ → T₁ transitions are predominantly confined to the anthracene segment, indicating a locally excited (LE) state-controlled luminescence mechanism. This LE-dominant character is experimentally validated by the negligible solvatochromism across various solvents. Notably, optimized OLEDs based on CAP demonstrate ultrapure deep-blue electroluminescence with CIE coordinates of (0.15, 0.05), a maximum external quantum efficiency (EQE_max) of 4.18%, and a full width at half maximum (FWHM) of 50 nm. These findings highlight the significant potential of anthracene-derived architectures for the development of high-performance ultrapure deep-blue electroluminescent materials.