Green Synthesis of High-Performance Conjugated Polymers through Optimizing Fused-Ring Structures and Molecular Weights for Organic Field-Effect Transistors

Facile and ecofriendly syntheses are of vital importance to the development of organic semiconductors. Herein, we present a straightforward and green approach for preparing high-performance conjugated polymers. A series of conjugated polymers based on three commercially available multifused rings and benzodifuranedione were designed and synthesized for application in organic field-effect transistors (OFETs). The optical properties, molecular orbital energy levels, and microstructures were systematically investigated. Polymer-based field-effect devices were also fabricated and the electrical properties were optimized by extending the conjugation length, varying the multifused ring structures, and enhancing the molecular weight. The conjugated polymer featuring heptacyclic arenes (dithienothiophen[3,2-b]-pyrrolobenzothiadiazole) achieved a maximum mobility exceeding 1.4 cm² V^-1 s^-1 and an I_on/I_off ratio surpassing 10⁶. This work presents a green aldol synthesis strategy for the preparation of high-performance polymer semiconductor materials.