Color stable white organic light-emitting diode based on a novel triazine derivative

A novel red-orange emitting material with a branched molecular structure, 2,4,6-tris[2-(N-ethyl-3-carbazole)carboxethenyl]-1,3,5-s-triazine (TC3), has been synthesized and characterized using UV-visible, photoluminescence (PL) and electroluminescence (EL) spectroscopy. White EL devices were fabricated using TO as a red-orange emitter and 8-hydroxyquinolinolato lithium (Liq) as a blue-green emitter. N,N-bis(3-methylphenyl)-N,N-diphenylbenzidine (TPD) as the adjustor for charge carrier mobility was introduced between the two emitting layers to improve the stability of the white emission color on bias voltage. The EL devices of ITO/poly(N-vinylcarbazole) (PVK):TC3 (56 nm)/TPD (5 nm)/Liq (30 nm)/Mg:Ag exhibited good quality white emission. The Commission Internationale De L'Eclairage chromaticity coordinates are (0.34,0.39) and are stable on the bias voltage. (C) 2007 Elsevier B.V. All rights reserved.