Van der Waals Cobalt Two-Dimensional Metal–Organic Frameworks Exhibiting Robust Ferroelectric Switching for Memory Devices

Ferroelectric field-effect transistors (FeFETs) are emerging as promising candidates for next-generation nonvolatile memory and computing technologies. While metal–organic frameworks (MOFs) offer high control over structure & performance. In this work, we report the development of a cobalt-based 2D metal–organic framework (MOF) exhibiting ferroelectric behavior. Single-crystal structural analysis reveals that the Co ions adopt an octahedral coordination environment, forming a 2D connected framework where adjacent layers are stabilized by weak van der Waals (π–π stacking) interactions. Mechanical exfoliation of the crystals demonstrated excellent layer control, surpassing that typically achieved in graphene systems. Layer-dependent ferroelectric properties were investigated, confirming robust ferroelectric switching at reduced thicknesses. The fabricated FeFET devices based on this 2D MOF exhibited a high on/off ratio, demonstrating their potential for nonvolatile memory applications. Magnetic measurements indicate that the material is paramagnetic in nature, offering additional opportunities for multifunctional device integration.