Zeolitic-imidazole framework thin film-based flexible resistive switching memory

As some of the organic–inorganic hybrid materials that have been researched actively for decades, metal–organic frameworks (MOFs) have been studied in various fields due to their high chemical tunability and stability. MOFs could be characterized by their various crystal structures and 3-dimensional porous structures, and, by changing the framework, can be useful for applications such as catalysis, chemical sensing, and gas separation. Due to their structural complexity and difficulties in making the desired form of framework, MOFs have not been widely explored in the field of electronic devices. In this work, we designed resistive switching random access memory (ReRAM) by introducing a zeolitic imidazolate framework (ZIF)-8 thin film as the resistive switching layer. ZIF-8 is one of the MOF materials with a sodalite zeolite-type structure, which includes zinc ions and 2-methylimidazole as the metal nodes and organic linkers. ZIF-8 thin film-based ReRAM possesses consistent resistive switching behavior. Synthesis of the ZIF-8 thin film is accomplished using simple solution processes. Characteristics of the thin film were confirmed using X-ray diffraction and scanning-electron microscopy. Its resistive switching properties as well as the mechanical flexibility were tested using flexible memory devices on plastic substrates. The resistive switching behavior of ZIF-8 could be explained by the redox-active nature of its linker molecules, which enables electrons to be transported from one electrode to the other.