APPROACHES TO CONDUCTING POLYMER DEVICES WITH NANOSTRUCTURES - PHOTOELECTROCHEMICAL FUNCTION OF ONE-DIMENSIONAL AND 2-DIMENSIONAL PORPHYRINPOLYMERS WITH OLIGOTHIENYL MOLECULAR WIRE

The nanofabrication of molecular semiconductors for the construction o f molecular photoelectronic devices is an important area of research; to this end, we have constructed porphyrin polymers possessing a tailo r-made structure. In this paper, we report the photoelectronic functio n of the porphyrin polymers connected by oligothienyl bridges. One-dim ensional porphyrin polymers with various lengths of oligothienyl bridg e in the axial direction were synthesized by the electrochemical polym erization of symmetrical bis(oligothienylalkoxy) phosphorus(V)-porphyr in. The conductivity of the polymer was strongly enhanced by photoirra diation, indicating photoinduced carrier formation. The layered sandwi ch cell of the polymer with polybithiophene showed electric rectifying properties in the dark. Interestingly, photovoltage and photocurrent were observed on photoirradiation. On the basis of these results, a mi croscopic polymerjunction chip was constructed. Two-dimensional porphy rin polymers containing oligothienyl bridges in the lateral direction were prepared by similar electrochemical oxidation of meso-tetrakis (o ligothienyl) porphyrin metal complexes and were fabricated as layered diodes.