Abstract
Organic light-emitting diodes (OLEDs) represent the most successfully commercialized organic electronic devices. However, achieving blue emission with simultaneously high efficiency, color purity, and operational stability remains a significant challenge1. Multiple resonance (MR) fluorophores have emerged as promising emitters2 due to their intrinsically narrow emission spectra arising from specific patterns of frontier molecular orbitals with multiple nodes, which suppress electron-vibrational coupling. Diindolophenazine (DIPz) derivatives constitute a novel class of MR fluorophores that, when embedded in anthracene-based TTA hosts, have demonstrated ultranarrow fluorescence and reasonable OLED efficiencies. We synthesized three novel DIPz derivatives—PhDIPz, tBuPhDIPz, and MesDIPz—and fabricated OLED devices to evaluate their electroluminescent performance.