Synthesis and Electroluminescent Properties of Phenyl-Substituted Poly(phenylenevinylene)

Poly(phenylenevinylene) (PPV) is one of the most efficient electroluminescent conjugated polymers and has the potential to be commercialized as important components in full-color flat panel displays. Here, we report an alternative synthetic route to the commercially available PPV derivative Super Yellow PPV (SY PPV) using 2-bromo-1,4-xylylene diacetate as a novel starting material. The intermediates, monomers, and the polymer were fully characterized by nuclear magnetic resonance (NMR) and elemental analysis. The SY PPV film shows an absorption maximum at 434 nm and an absorption onset at 510 nm with an optical bandgap of ca 2.44 eV. The photoluminescent and electroluminescent maximum of SY PPV are around 516 and 552 nm, respectively. The SY PPV obtained via this new synthetic route exhibits improved electroluminescent properties, a turn on voltage of over 2.4 V, a luminance maximum exceeding 49000 cd·m^-2, and a maximum luminous efficiency (LE) of 21 cd·A^-1 compared with the SY PPV prepared by the traditional route (16-18 cd·A^-1).