Synthesis and light-emitting properties of new poly(p-phenylenevinylene) derivatives containing oxadiazole moiety

Abstract

Two new poly(p-phenylenevinylene) (PPV) derivatives containing the oxadiazole moiety (OXA–PPV1 and OXA–PPV2) were synthesized by the Wittig condensation polymerization reaction and their thermal and light-emitting properties were investigated. The single-layer and triple-layer electroluminescent (EL) devices with configurations of ITO/OXA–PPV1/Al and ITO/OXA–PPV1/OXD/Alq3/Al were fabricated. They both exhibited blue emission at 460 nm. For comparison, the PPV derivative containing the oxadiazole moiety only in the side chains (OXA–PPV2) was also synthesized. Both single-layer and triple-layer EL devices with OXA–PPV2 as the emissive layer emitted green-light at 560 nm. The turn-on voltages of the triple-layer device was 11 V for OXA–PPV1 and 8 V for OXA–PPV2. The triple-layer EL devices showed much better performance than that of the single-layer devices. The spectra indicated that energy or electron transfer occurred from the side-chain oxadiazole to the main-chain styrene unit. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2424–2428, 2002