Enhancing the performance of polyoxometalate-based memristors in harsh environments based on hydrogen bonding and cooperative π-conjugation interactions†

Abstract

Polyoxometalates (POMs), as a class of structurally well-defined compounds with excellent charge trapping and releasing capabilities, are ideal candidates for high-performance memory devices. However, their performance optimization in conventional environments remains limited. Here, three water-soluble organic–inorganic hybridized POM-based nonvolatile memory devices are proposed. Pure inorganic vanadoborates clusters are assembled with organic ligands by electrostatic and covalent interactions. This approach modulates the hydrophilicity and stability of the resulting compounds. Structural analysis and two-dimensional correlation infrared (2D-COS-IR) spectroscopy reveal that hydrogen bonding and π-conjugation interactions may influence the performance of POM-based memristors. The resistive switching (RS) mechanism could be controlled by the synergistic effect of space-charge-limited current and oxygen vacancies. Notably, FTO/VB3/Ag, modified with hydrogen bonding and constructed with Li⁺, exhibits rewritable RS behavior and a high ON/OFF current ratio of 2.62 × 10⁴, even at 270 °C and various harsh environments. Additionally, this study represents the first example of using 2D-COS-IR to investigate the  dynamic evolution of weak intermolecular interactions within the device during heating, and elucidating the mechanisms that memristors enable stable operation at high temperatures. This work explores the relationship between the structure and RS performance of the material, proposes a method for designing and enhancing memristor performance at the molecular level, and offers a theoretical foundation for the development of high-performance memory devices for extreme environments.