High Mobility Single-Crystal Field-Effect Transistors from Bisindoloquinoline Semiconductors

A novel heptacyclic bisindoloquinoline-based organic semiconductor has been synthesized, characterized, and used to fabricate single-crystal field-effect transistors. A synthetic route was developed for the synthesis of heptacyclic bis(indolo{1,2-a})quinoline via an intramolecular cyclization of anthrazoline derivatives. Single-crystal X-ray structure revealed that the seven fused rings of bis(indolo{1,2-a})quinoline are relatively coplanar and lead to a slipped face-to-face π-stacking with the shortest intermolecular spacing of 3.3 Å. Single-crystal field-effect transistors based on the bis(indolo{1,2-a})quinoline had carrier mobility as high as 1.0 cm2/V·s with on/off ratios greater than 104.