Room-Temperature Interfacial Synthesis of Vinylene-Bridged Two-Dimensional Covalent Organic Framework Thin Film for Nonvolatile Memory
Dongchuang Wu, Qiang Che, Haidong He, Mohamed E. El‐Khouly, Senhe Huang, Xiaodong Zhuang, Bin Zhang, Yu Chen
Abstract
The development of large-area two-dimensional all sp 2 carbon-linked covalent organic frameworks (COFs) film still remains a challenge, because of the shortage of the effective synthesis methods and optimal building blocks. To date, all vinylene-bridged COFs synthesized by solvothermal method at high temperatures and pressures are insoluble and unprocessable powders, which lead to a formidable challenge in fabricating thin film-based electronic and optoelectronic devices. By using a liquid–liquid interface polymerization strategy, a vinylene-bridged COF film with a complete sp 2 -carbon skeleton has been successfully synthesized for the first time at room temperature. The COF nanospheres initially formed at the liquid–liquid interface slowly transmuted themselves into self-standing COF thin films with long-range ordered arrangement by covalent self-assembly. The as-fabricated electronic device with a configuration of Al/COFs/ITO exhibited a nonvolatile rewritable memory effect with a low switching-on voltage of +0.84 V. Associated with its bistable switching performance, this device is capable of executing simple “OR” logic operations.