Improved resistive switching performance through donor-acceptor structure construction in memristors based on covalent organic framework films

Covalent organic frameworks (COFs) with high crystallinity and tunable chemical structures have been promising materials for high-density organic memory and neuromorphic devices. However, reports on regulating resistive switching performances via tailoring the chemical structures of COF films are still limited. In this work, by fabricating two COF film-based memristor devices with different donor-acceptor structures (TAPA-TP and TAPA-TFB), we studied the impact of acceptors on the resistive memory performance of COF-based devices. By comparison, TAPA-TP film with ketone groups as electron acceptors showed an enhanced nonvolatile rewritable memory effect, with a small turn-on voltage of +0.9 V, an enhanced ON/OFF state current ratio and a long-term retention time. Additionally, the devices demonstrated high reproducibility of rewritable memory. Conversely, the TAPA-TFB film, lacking acceptor groups, exhibited a poor memory effect. The switching mechanism suggests that the rewritable memory effect can be attributed to the electric field induced intramolecular charge transfer (CT) between the donors and acceptors. The impact of acceptors on memory performance was explored based on two COF film-based devices with different donor-acceptor structures.