Improved resistive switching behaviour in Ag–ZrO2 nanocomposite film

Abstract

The resistive switching behaviour and nonvolatile memory effects in zirconium oxide (ZrO₂) and silver nanoparticles (AgNP)-ZrO₂ nanocomposite films have been studied. To explore the role of adding AgNP in resistive switching of the nanocomposite films, fluorine-doped tin oxide (FTO)/AgNP-ZrO₂/silver (Ag) trilayer structure has been fabricated by spray coating of AgNPs-ZrO₂ on FTO with varying AgNP content in the nanocomposite film. X-ray diffraction (XRD) analysis confirms the single-phase ZrO₂ structure, with no additional peaks corresponding to AgNP due to its low concentration. Current (I)–voltage (V) measurement shows a decrease in switching voltage from 1.8 V for the pure ZrO₂ to 0.38 V for 1 wt% AgNP-ZrO₂ nanocomposite film. The cyclic I-V measurement shows an increase in the on–off ratio from 22 for pure ZrO₂ to 32 for 1 wt% AgNP-ZrO₂ nanocomposite devices. The retentivity measurement shows distinct on–off values for pure ZrO₂ and AgNP-ZrO₂ nanocomposite films over time. The temperature-dependent resistivity (R-T) measurements reveal that all devices (pure ZrO₂, 0.5 wt% AgNP-ZrO₂, and 1 wt% AgNP-ZrO₂) exhibit semiconducting behaviour in the high-resistance state, with activation energy decreasing from 87.1 to 48.43 meV as AgNP content increases. In the low-resistance state, all devices show metallic-like conduction. Additionally, the temperature coefficient of resistance (α) increases from 3.54 × 10^–3 K⁻¹ to 5.15 × 10^–2 K⁻¹ with higher AgNP concentration. The value of α is increased for AgNP-ZrO₂ nanocomposite compared to the ZrO₂ device, suggesting that in pure ZrO₂, only oxygen vacancies were involved, whereas, in AgNP-ZrO₂ nanocomposite, both oxygen vacancies and Ag metal nanoparticles participate in the formation of conducting filaments.

Graphical abstract