Substituted Indolo[3,2-b]Carbazoles: A New Class of Stable, High Mobility Organic Semiconductors for Thin Film Transistors

Properly functionalized indolo[3,2-b]carbazoles represent a new class of stable, high-mobility organic semiconductors for organic thin-film transistor applications. Both 5,11-disubstituted and peripherally substituted indolo[3,2-b]carbazoles with proper substituents self-organized into highly crystalline terrace-layered structures under suitable processing conditions. Organic TFTs using channel semiconductors of this nature exhibited excellent field-effect transistor properties, with mobility to 0.14 cm2 V-1 s-1 and current on/off ratio to 107. By virtue of their relatively low HOMO levels and large band gaps, this class of semiconductors also displayed excellent environmental stability under ambient conditions, an appealing characteristic for organic TFT applications.