Efficient electroluminescent poly(p-phenylene vinylene) copolymers for application in LEDs

A new and efficient route for the synthesis of poly(p-phenylene vinylene)s (PPVs) containing dialkoxy substituents at the 2,3-positions of the phenyle ne ring of the polymer backbone has been developed. In comparison to the mo re classical 2,5-substitution pattern these PPV polymers show a significant ly blue-shifted longest-wavelength absorption (lambda (max)) and emisson ba nd (lambda (em)). Two statistical PPV copolymers comprising 2,3-dibutoxy an d dimethyloctylsilyl- or 2,5-bis(dimethyloctylsilyl) side-chains were synth esized via the Gilch dehydrohalogenation route. Double-layer light-emitting devices (LEDs) of the configuration ITO/PEDOT/polymer/Ca were demonstrated to combine high electroluminescence efficiencies with low turn-on voltages .