Structure, Physical Properties and Thin-Film Transistor Characteristics of Sexithiophene Isomers

Abstract

We have synthesized unsubstituted oligothiophenes with both terminal thiophene rings linked at β-positions. The correlation between molecular structure, character of a single molecule such as conjugation length, and physical properties as solid has been investigated. Moreover, the influence on electric properties of their thin films has been investigated. It was revealed that π-conjugation length of the molecule considerably influences the field-effect transistor characteristic.

Keywords:

• charge mobility
• conjugation length
• isomer
• oligothiophene
• molecular structure
• thin film transistor

Acknowledgments

We thank Mr. J. Chisaka for his guidance in thin-film preparation and characterization. We also appreciate Drs. T. Kimura and M. Misaki for their guidance in DSC analysis.