Blue electroluminescent devices with high quantum efficiency from alkoxy-substituted poly(para-phenylene vinylene)-trimers in a polystyrene matrix

We report electroluminescence of electroluminescent devices fabricated from cis,trans- 2,5-dimethoxy-1,4 -bis[2-(3,4,5-trimethoxyphenyl)ethenyl]benzene blended in a polystyrene matrix as emission layer. This choice of materials avoids the inherently poor miscibility of polymers with other compounds and minimizes interactions between the host polymer and the electro-optically active guest, which can produce quenching sites. A blue light-emitting device with high internal quantum efficiency (∼1%) results.