Chemical Vapor-Deposited Vanadium Pentoxide Nanosheets with Highly Stable and Low Switching Voltages for Effective...

Recently, attempts to overcome the physical limits of memory devices have led to the development of promising materials and architectures for next-generation memory technology. The selector device is one of the essential ingredients of high-density stacked memory systems. However, complicated constituent deposition conditions and thermal degradation are problematic, even with effective selector device materials. Herein, we demonstrate the highly stable and low-threshold voltages of vanadium pentoxide (V₂O₅) nanosheets synthesized by facile chemical vapor deposition, which have not been previously reported on the threshold switching (TS) properties. The electrons occupying trap sites in poly-crystalline V₂O₅ nanosheet contribute to the perfectly symmetric TS feature at the bias polarity and low-threshold voltages in V₂O₅, confirmed by high-resolution transmission electron microscopy measurements. Furthermore, we find an additional PdO interlayer in V₂O₅ nanodevices connected with a Pd/Au electrode after thermal annealing treatment. The PdO interlayer decreases the threshold voltages, and the I_on/ I_off ratio increases because of the increased trap density of V₂O₅. These studies provide insights into V₂O₅ switching characteristics, which can support low power consumption in nonvolatile memory devices.