A Novel Yellow Fluorescent Dopant for High-Performance Organic Electroluminescent Devices

Abstract

We have synthesized a novel yellow dopant (DCTP) for applications in organic light-emitting devices (OLEDs), by introducing a triphenylamine segment as a π electron donor and 4-(dicyanomethylene)-2-(tert-butyl)-4H-pyran moiety as a π electron acceptor to the molecular structure. The resultant dopant has a high fluorescent yield and a sterically well-hindered structure. Its photoluminescence in solution and electroluminescence have been studied. The DCTP-doped OLED with a structure of indium tin oxide/N,N‘-bis(3-methylphenyl)-N,N‘-diphenyl-1,1‘-biphenyl-4,4‘-diamine (TPD)/tris(8-quinolinolato)aluminum (Alq3):2 wt % DCTP/Alq3/Mg:Ag shows a bright yellow emission (chromaticity coordinates: x = 0.47; y = 0.51) and a brightness of 19 383 cd/m2 at a driving voltage of 20 V. The current efficiency of the device reaches 5.3 cd/A at a current density of 20 mA/cm2 and a voltage of 11 V.