Efficient Diphenylamino-Spirobifluorenefumaronitrile red fluorophore for Organic Light-Emitting Diodes

摘要

Deep red fluorescent compound bearing spiro-diphenylamino electron-donor and cyano electron-acceptor was designed and synthesized. The fluorescenle-quenching of the material was largely suppressed by the bulky 9,9'-substituent (spiro-fused bifluorene) as wall as the non-planar diphenylamino group. DPASPFN (2,3-bis(2-(diphenylamino)-9,9'- spirobifluorene-7-ylfumaronitrile) show intense fluorescence in solid state (Φ_f > 30 %). Non-doped red OLEDs fabricated with DPASPFN exhibit authentic red (CIE, x = 0.65, y = 0.30) electroluminescence with brightness of 1703 cd m~(-2) and external quantum efficiency as high as 1.96%. Doped red OLEDs fabricated with DPASPFN exhibit saturated orange (CIE, x = 0.54, y = 0.45) electroluminescence with brightness of 17290 cd m~(-2) and external quantum efficiency as high as 3.81%.