Synthesis and light-emitting properties of new polyfluorene copolymers containing a triphenylamine based hydrazone comonomer

Polyfluorene copolymers containing a triphenylamine based hydrazone derivative, bis(4-bromo-phenyl)-[4-(diphenylhydrazonomethyl)phenyl]amine (TPAH), as a comonomer have been synthesized through Ni(0) mediated polymerization. Light-emitting properties of the copolymers composed of TPAH and 2,5-dibromo-bis-9,9-(2'-ethylhexyl)fluorene (BEHF) were compared with those of poly[bis-9,9-(2-ethylhexyl)fluorene] (PBEHF) homopolymer. Light-emitting diodes were fabricated in an ITO (indium-tin oxide)/PEDOT/polymer/Ca/Al configuration. The EL devices constructed from the copolymers exhibited device performances that were highly improved than that of the device using the PBEHF homopolymer. (c) 2005 Elsevier B.V. All rights reserved.