Reliable resistive switching and synaptic simulation behaviors in ammonium polyphosphate-based memristor with non-inert Al electrode

Abstract

Memristive devices that integrate storage and computing capabilities are highly promising candidates for artificial synapses in neuromorphic systems. However, achieving both cost-effectiveness and high-performance in memristors remains a substantial challenge. Ammonium polyphosphate (APP), an all-inorganic ionic polymer, has been utilized in the fabrication of memristive devices due to its distinctive poly-ionic properties and exceptional ion mobility. In this study, a two-terminal APP-based memristor with an Al/APP/ITO structure was fabricated. The experimental results revealed improved bipolar resistive switching behavior, characterized by lower operating voltages, enhanced endurance performance, and extended retention time. Detailed data fitting and chemical bonding analysis suggest that the physical mechanism underlying resistive switching involves a combination of interfacial Schottky barrier and conductive filaments. Furthermore, adjustable device conductance is achieved by applying consecutive positive and negative voltage sweeps. Various synaptic functions, including excitatory postsynaptic current, short-term paired-pulse facilitation, long-term potentiation /depression, and spike-timing-dependent plasticity, are effectively emulated. This study presents an effective approach to enhancing the memristive characteristics of APP-based devices and positions APP as a viable candidate for innovative neuromorphic architectures.

Keywords

• all-inorganic ionic polymer
• ammonium polyphosphate
• memristor
• conductive filament
• Schottky barrier
• artificial synapse