Rational Device Design and Doping‐Controlled Performance in Fast‐Response π‐Ion Gel Transistors (Adv. Funct. Mater. 29/2026)

π-Ion Gel Transistors The cover image illustrates a π-ion gel transistor (PIGT) with microsecond-scale response. In their Research Article (10.1002/adfm.202521674), Soh Kushida, Yohei Yamamoto, and co-workers demonstrate P3HT-based PIGTs combining high transconductance and fast switching. Hole-scavenger doping with BIH suppresses offset current and maintains a high on/off ratio, enabling high-performance organic electrochemical transistors.