Functionalized Poly(phenylene ether) with high thermal stability as flexible dielectrics and substrates for organic field-effect transistors

Extensive research efforts are devoted into seeking the thermally and mechanically durable dielectric materials for flexible electronics. In this work, a series of sulfonylated poly (phenylene ether)s (PPEs) were synthesized and served as gate dielectrics in the flexible OFET devices with crosslinked poly (2-allyl-6-methylphenol-co-2,6-dimethylphenol) (APPE) as substrate. The chemical structure, thermal, morphology, and dielectric properties were investigated, and the corresponding OFET devices were accordingly fabricated and characterized. We found that the discrepancy in sulfone content of PPE-xS renders the difference in thermal stability, surface polarity and dielectric constants. Among them, PPE-9kS with the highest sulfone content of 63% shows the best dielectric properties in the flexible OFET devices with hole mobility (μp) of 0.45 cm2 V?1 s?1, outperforming its parent polymer without sulfone group (PPE-9k) with μp of 0.14 cm2 V?1 s?1. Besides, the flexible device with PPE-9kS as dielectric exhibits highly retained device performance after cyclic bending or thermal treatment, which indicates the decent mechanical and thermal durability. The present study documents a practical methodology to fabricate a high-performance flexible OFET with excellent thermal and mechanical stability. ? 2021 Elsevier B.V.