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

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 degrees C. The mesomorphic columnar structures are stabilized by nanosegregation promoted by the interaction between the oligosiloxane moieties. The electron mobility exceeds 0.1 cm(2)V(-1)s(-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 pi-conjugated cores, resulting in high electron mobilities.