Enhancing the Memristor Performance through Tuning the Energy Bands of Hexahydroxy-Based Metal–Organic Framework Films

Precisely adjusting the energy band of metal-organic frameworks (MOFs) in the resistive memory is a useful yet challenging method to manipulate the resistance and ON/OFF ratio of the device. In this study, a series of new MOF films with tunable band structure, high crystallinity, and excellent self-supporting characteristics were obtained by changing different ligands and metal ions. Using these MOF films as active layers, the ITO/2D MOF/Al memory devices exhibit excellent resistive switching behavior: high uniformity and repeatability, excellent durability, and long retention characteristics. Changing the metal ion species or organic ligand molecules can effectively regulate the energy bands of 2D MOF films, so that the device presents an adjustable memory window from 10³ to 10⁸, and the memory window of the ITO/Co₃(HPTT)₂/Al device is as high as 10⁸, higher than those of reported memory devices based on inorganic 2D materials such as traditional chalcogenides and transition metal oxides. The RS mechanism of the device is determined to be the conductive filament formed by the atomic-level displacement of metal ions in the 2D MOF film, and the difference of the set voltage and switching ratio of the device is closely related to the injection barriers of the charge carrier.