Fundamental Properties of Ferroelectric Liquid-Crystalline Conductive Polymers

Poly(2-methoxy, 5-(4-decyloxy-biphenyl-4'-(1, 10-dioxydecane))-p-phenylenevinylene), MDBD-PPV, with a long side chain containing alkoxybiphenyl mesogenic unit has been synthesized and its electrical and optical properties have been investigated. This polymer showed a microscopic texture typical to the liquid-crystalline phase and a sharp X-ray diffraction peak due to the smectic layer structure. The band gap of MDBD-PPV in the liquid-crystalline phase has been estimated to be about 2.3 eV. An electroluminescent (EL) device has been fabricated using this liquid-crystalline polymer. MDBD-PPV, as an emissive layer and the polarity effect has been observed in the emission spectra of this EL device.