Electronic Functions and Molecular Aggregation of Liquid-Crystalline Perylene Tetracarboxylic Bisimide Derivatives Bearing Oligosiloxane Chains

Abstract

Liquid-crystalline semiconductors exhibit good carrier transport properties as well as solution-processability. The applications to field-effect transistors, light-emitting diodes, and solar cells have been studied.
Liquid-crystalline perylene tetracarboxylic bisimide derivatives bearing oligosiloxane moieties were designed. They exhibit columnar phases at room temperature and do not crystallize even when they are cooled to −100°C. The mesomorphic columnar structures are stabilized by nanosegregation promoted by the interaction between the oligosiloxane moieties. The electron mobility exceeds 0.1 cm²V⁻¹s⁻¹ at room temperature in the ordered columnar phase. The analysis of the electron transport characteristics in the columnar phases indicates closed aggregation of the π-conjugated cores, resulting in high electron mobilities.