Blue emitting materials based on diphenylamine-substituted diphenylvinylarenes for OLEDs

Abstract

To develop the efficient blue emitters for Organic light-emitting diodes (OLEDs), this paper reports the synthesis and electroluminescent properties of diphenylvinylarenes end-capped with diphenylamine groups. Two OLEDs were fabricated in the following sequence: indium-tin-oxide (ITO) / N,N-di(1-naphthyl)-N,N-diphenyl-(1,1-biphenyl)-4,4-diam-ine (NPB) (50nm) / Blue emitters (30nm) / bathophenanthroline (Bphen) (30nm) / lithium quinolate (Liq) (2nm) /Al (100nm). Two devices exhi-bited blue electroluminescence. In particular, a device using 9,9-diethyl-N,N-diphenyl-7-(2,2-diphenylvinyl)-9H-fluoren-2-amine exhibited blue emission with a luminance efficiency, a power efficiency, an external quantum efficiency and Commission Internationale d'Enclairage (CIE) coordinates of 5.48 cd/A, 2.45lm/W, 2.85% at 20mA/cm(2) and (x = 0.17, y = 0.25) at 8.0V, respectively.