Cyano-containing phenylene vinylene-based copolymer as blue luminescent and electron transport material in polymer light-emitting diodes

The new soluble cyano-containing phenylene vinylene copolymer with well-defined conjugating length was synthesized and characterized by use of thermal analysis and spectroscopy (infrared, ultraviolet-visible, photoluminescence, cyclic voltammetry) measurement. This new polymer can be used as a blue electroluminescent material and as an electron transport/hole blocking layer in polymer light-emitting diodes using poly(p-phenylene vinylene) (PPV) as the active luminescent layer. The transfer efficiency of current density to brightness of PPV devices with the introduction of the new polymer as electron transporting layer increases by a factor of 25. (C) 1999 American Institute of Physics. [S0021-8979(99)00804-X].