Unique properties of conducting polymers of non-degenerated structures poly(3-alkylthiophene) and poly(9-alkylfluorene) mixed with polyacetylene derivatives poly(o-trimethylsilylphenylacetylene)

Electrical and optical properties of conducting polymers of non-degenerated structures such as poly(3-alkylthiophene) (PAT) and poly(9-alkylfluorene) (PAF) exhibit unique changes upon mixing with degenerated structure such as poly(o-trimethylsilylphenylacetylene) (PTMSiPA). By the introduction of small amount PTMSiPA, electrical conductivity of PAT increases and its temperature dependence becomes much smaller. Photoluminescence (PL) spectrum of PAT changes drastically and its intensity decreases upon introduction of PTMSiPA in which PL is negligible. PL intensity is linearly dependent on the concentration of PAT. However, non-linear dependence of PL has been observed in PAF mixed with PTMSiPA. The origin of these anomalies is discussed by taking electronic energy states of PAT, PAF, and PTMSiPA into consideration.