Tunable, reversible resistive switching behavior of PVA-zirconia nanocomposite films and validation of the trap-assisted switching mechanism by the selective application of external bias voltages

Flexible, free-standing polyvinyl alcohol (PVA)-zirconia (mean particle size similar to 24 nm) nanocomposite films have been synthesized and their performance as a potential next-generation resistive switching device material has been assessed in this report. The nanocomposite films switch from a high resistive state (HRS) to a low resistive state (LRS) at the SET potential and from LRS to HRS at the RESET potential within the voltage window of 5 V. The origination of trap-assisted SET/RESET potentials has been experimentally validated by analyzing the experimental data and invoking various theoretical models. The impregnation of zirconium dioxide (ZrO2) nanoparticles considerably enhances the interfacial charges facilitated by the formation of dangling bonds. The current (I)-voltage (V) characteristics elucidate how the alteration of free volumetric space in the nanocomposites can modify the SET-RESET potential. This leads to tunable SET/RESET potential, good resistance ratio (similar to 80), and extensive cycling ability of these PVA-ZrO2 organic flexible nanocomposite films. Herein, we have also investigated the effect of applying external bias voltage (equal to the RESET potential) for possible energy bandgap modification and polymer chain orientation. The impedance spectra differ considerably when the sample is subjected to SET, RESET, and zero voltage bias. The observations have been correlated with the UV-vis absorption spectra and electrical studies. The adopted analysis method and obtained results can open up new avenues for designing and analyzing resistive switching-based random-access memory devices.

Automated summary

In this study, flexible and free-standing polyvinyl alcohol (PVA)-zirconia nanocomposite films were synthesized and evaluated as a potential material for next-generation resistive switching devices. The nanocomposite films exhibited high resistive and low resistive states within a voltage window of 5 V. The origin of trap-assisted SET/RESET potentials was experimentally validated, and the impregnation of zirconium dioxide (ZrO2) nanoparticles enhanced interfacial charges. The current-voltage characteristics showed tunable SET/RESET potential, good resistance ratio, and excellent cycling ability of the PVA-ZrO2 nanocomposite films.