Electrical Properties of Poly (1,4-phenylene vinylene-co-2,5-dimethoxy-1,4-phenylene vinylene)s and Poly(1,4-phenylene vinylene-co-2,5-thienylene vinylene)s

摘要

The temperature dependence of electrical conductivities and thermoelectric power of I2-doped poly(1,4-penylene vinylene-co-2,5-dimethoxy-1,4-phenylene vinylene)s [poly(PV-co-DMPV)] and poly(1,4-phenylene vinylene-co-2,5-thienylene vinylene)s [poly(PV-co-TV)] were studied. The former copolymers were also doped with FeCl3. All the samples used were in thin film forms. The temperature dependence of electrical conductivity implies that the variable range hopping conduction mechanism applises to these systems. The activation energy for the electrical conduction in dimethoxy-phenylene vinylene (DMPV) copolymers ranged from about 7 to 30 meV depending on the polymer composition and the nature of the dopant. It was significantly higher for I2-doped thienylene vinylene (TV) copolymers, namely 90-200 meV. The values of the room temperature thermoelectric power were 30-70レV/K for DMPV copolymer and 100-800レV/K for TV copolymers. Anisotropy in the electrical conductivities was also studied for oriented films obtained by uniaxial stretching of the precursor polymer films.