Transient photocurrent in poly(3-octadecylthiophene) near the solid–liquid phase transition

摘要: Abstract Poly(3-alkylthiophene)s (PATs) are conducting polymers possessing high processabilities such as solubility and fusibility. Most known to be p-type, or hole transporting semiconductors. PATs also p-type semiconductors in the solid state. Previous studies have suggested that dominant photocarrier inverts from positive negative liquid state PAT with relatively long alkyl side chain. In this study, we tried confirm sign inversion of regiorandom poly(3-octadecylthiophene) (PAT18) by means time-of-flight method. It was found mobility decreases increasing temperature. At temperature near solid–liquid phase transition, drastically, eventually melting temperature, it impossible evaluate noisy transient photocurrent. On other hand, photocurrents based on electron transport observed above point. The carrier evaluated range 10−6 10−5 cm2/V s, which is comparably at This fact suggests same mechanism, for example interchain hopping limits transport, electron. unique phenomenon interpreted modulation electronic energy caused conformational change main