Resistive switching behavior and mechanism of room-temperature-fabricated flexible Al/TiS2-PVP/ITO/PET memory devices

Abstract The mixture of two-dimensional (2D) TiS 2 nanoflakes and polyvinylpyrrolidone (PVP) exhibits a nonvolatile, bipolar resistive switching behavior with a low resistance state (LRS)/high resistance state (HRS) current ratio of ∼10 2 in the devices with a flexible Al/TiS 2 -PVP/indium tin oxide (ITO)/polyethylene terephthalate (PET) structure. The polymer-assistant liquid-phase exfoliation of 2D nanoflakes from TiS 2 bulk material is processed in low-boiling solvent. And the fabrication process of these devices is performed entirely at room temperature. Such an energy-saving and scalable production process indicates a huge potential of large-scale industrial application. The AFM and TEM characterizations showed that the exfoliated 2D TiS 2 are flakes at micrometer scale with a layer-number of mostly 7 or 8. Both the HRS and the LRS can be kept for more than 10 4  s. The endurance of devices was obtained over 100 direct current (DC) sweeping cycles with remarkable separations between different resistive states. The distributions of writing (set) and erasing (reset) voltages show that set and reset voltages are small (