Synthesis, characterization, and tunable semiconducting properties of aza-BODIPY derived polycyclic aromatic dyes

Azadipyrromethene derived polycyclic aromatic complexes (HBPs) containing thirteen fused rings have been synthesized, which show highly selective intense absorption in the near infrared spectrum (NIR) region with high photo- and thermo-stability. The periphery alkoxy and alkyl substituents greatly affect their molecular packing structures in thin films and their thin film transistor performances. With the simple changes of the alkyl substituents, the packing structures changed from discrete-grain with H-aggregation type absorption to lamellar packing with J-aggregation type absorption, and the semiconducting properties were modulated from p-type to interesting ambipolar-type in solution-processed organic field effect transistors (OFETs) with hole and electron mobilities reaching to 0.42 and 0.17 cm2 V−1 s−1, respectively.