基于二萘并[2,3-B∶2′,3′-D]呋喃基团的高效窄发射蓝光 OLED 器件

High-efficiency narrow-emission blue organic light-emitting device（OLED）is one of the research hotspots in the field of flexible display. In this paper，a D-A-D blue molecule，DPF-NA was designed and synthesized by using dinaphthyl［2，3-B∶2′，3′-D］furan as a weak electron acceptor and N-（4-biphenylyl）-1-naphthylamine as electron donors. The moleculeshows a photoluminescence（PL）peak at 441 nm in n-hexane solution. Theoretical calculations and photophysical measurements show that DPF-NA possesses hybridized localized charge transfer （HLCT）excited state characteristics，combining high luminescence efficiency of the localized state（LE）and high exciton utilization of the charge transfer（CT）state. As a consequence，the molecule shows a high PL photoluminescence quantum efficiency（PLQY）of 81. 2% in dichloromethane solution. OLED devices based on the DPF-NA film （with a doping concentration of 3%（mass fraction））has an electroluminescence（EL）peak located at 455 nm，with a small full width at half maximum（FWHM）of 26 nm. The CIE coordinates are（0. 14，0. 08），and the maximum external quantum efficiency（EQE_max）is 6. 76%.