Flexible Metal‐Free Memory Electronic Made of π‐Conjugation‐Interrupted Hyperbranched Polymer Switch and Reduced Graphene Oxide Electrodes

A flexible metal‐free flash memory device with reduced graphene oxide films as electrodes and diarylfluorene‐based π‐conjugation‐interrupted hyperbranched polymers (CIHPs) as active switches is reported. Two CIHPs, named PCzPF and PCzPF‐PF, are synthesized via BF₃?Et₂O‐catalyzed fluorenol’s Friedel–Crafts reaction, where the PCzPF‐PF is designed by the decoration of hindrance functional groups, i.e., bulky 9‐phenyl‐fluorenyl (PF) moieties, at the end‐groups of PCzPF. Both of the two CIHPs exhibit excellent solubility and thermal stability. The PCzPF‐based device exhibits no switching effect while the PCzPF‐PF‐based device shows a flash type memory effect, indicating the incorporation of PF groups plays a critical role in realizing electrically bistable behaviors. In particular, the optimized memory exhibits a high ON/OFF ratio of > 3.0 × 10³, long retention time of up to 1.2 × 10⁴ s, and high mechanical stability. This work opens a new avenue for metal‐free memory electronics through a low‐cost and full‐solution process approach.