A Novel Design Strategy for Benzo[b]Thiophene Substituted Multiple Resonance Type Blue Fluorescent Dopant With...

Conventional blue fluorescent emitters suffer from low efficiency and broad full width at half maximum (FWHM), limiting their application in next-generation organic light-emitting diodes (OLEDs). In this work, we report a novel double boron-based multi-resonance-type blue fluorescent emitter, v-DABNA-BT by incorporating a benzo[b]thiophene unit into the v-DABNA core to address the efficiency and color purity issues of the blue OLEDs. The v-DABNA-BT exhibited deep blue emission with a photoluminescence peak at 466 nm and an exceptionally narrow FWHM of 13.9 nm. As a pure blue fluorescent emitter, it delivered a high external quantum efficiency of 10.8%, FWHM of 15.6 nm, and color coordinate of (0.115, 0.138). In addition, the v-DABNA-BT-based hyperfluorescent (HF) OLEDs achieved a maximum external quantum efficiency of 28.7% with a FWHM of 18.2 nm, one of the best performances reported among HF systems employing pure fluorescent terminal emitters. This result underscores the potential of benzo[b] thiophene-modified boron-based MR-type fluorescent emitters as promising candidates for high-efficiency, high-color-purity OLED applications.