A-D-A small molecules featuring multi-fused rings and fluorinated benzothiadiazole for solution-processed organic field-effect transistors

Three small molecules with acceptor-donor-acceptor structure, featuring multi-fused rings (pentacyclic, heptacyclic, and octacyclic arenes) as donors and fluorinated benzothiadiazole as acceptor were synthesized and characterized for their applications in solution-processed organic field-effect transistors. The impact of different fused-ring structures of donor units on the optical and electrochemical properties, crystal structure, and charge carrier of the small molecule were systematically studied. The small molecule containing heptacyclic ladder-type arene demonstrated the highest field-effect performances, achieving a hole mobility of 0.29 cm²V^–1s^–1. Additionally, devices processed with non-chlorinated solvents also showed excellent mobility, approximately 0.20 cm²V^–1s^–1.