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

The mixture of two-dimensional (2D) TiS2 nanoflakes and polyvinylpyrrolidone (PVP) exhibits a nonvolatile, bipolar resistive switching behavior with a low resistance state (LRS)/high resistance state (HRS) current ratio of similar to 10(2) in the devices with a flexible Al/TiS2-PVP/indium fin oxide (ITO)/polyethylene terephthalate (PET) structure. The polymer-assistant liquid-phase exfoliation of 2D nanoflakes from TiS2 bulk material is processed in low-boiling solvent. And the fabrication process of these devices is performed entirely a 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 TiS2 are flakes a micrometer scale with a layer-number of mostly 7 or 8. Both the HRS and the LAS 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 ( < 2 V). Also, the resistive switching characteristics of the devices are stable during 1000 bending cycles. The switching behavior is explained by the thinning and recovery of Schottky barriers within devices.