Electrical and optical properties of liquid conducting polymer

Conducting polymers with substituted long side chain such as poly(3-alkylthiophene), poly(3-alkyl-selenophene), poly(3alkylfuran), poly(9-alkylfluorene), and poly(9,9-dialkylfluorene) are shown to melt at relatively low temperature. Electrical conductivity and photoluminescence exhibit an anomalous dependence on molecular structures at the melting point. A marked polarity effect of photoconduction has been observed. These results are discussed in terms of unique band schemes of the conducting polymers in the premelting region and in the liquid state