Organic Memristors with β-Controlled Hysteresis and Tunable Capacitive-Filamentary Switching

Abstract

Organic memristors are attracting increasing interest due to their potential in low-cost, flexible, and neuromorphic electronics. Despite ongoing research, the underlying switching mechanisms are not yet fully understood and require further systematic investigation. Herein, we present an ITO/PEDOT: PSS (+DMSO+TsOH) (PPDT)/PVA–PEG-H2SO4 ion-gel (IG)/Ag-based memristor that uniquely couples capacitive and filamentary switching through deliberate layer engineering. By tailoring active layer thickness, we unlock tunable transitions from capacitive-dominated to filament-assisted conduction, manifested as reversible shifts from nonpinched to pinched hysteresis loops, polarity reversal, and adjustable ON/OFF ratios. This dual-mode behavior is a direct consequence of protonic transport in the ion-gel matrix, which synergistically interacts with Ag+-driven filament formation and is stabilized by conductivity-enhanced PEDOT: PSS. Unlike conventional reports, this study integrates a β-controlled hysteresis framework that quantitatively links loop evolution with structural and electrical parameters, providing a unified description that bridges the gap between capacitive and resistive switching in polymer devices. We have also demonstrated (i) control of memristive state, (ii) the establishment of a generalized β-model for hysteresis tuning, and (iii) the fabrication of organic memristors that are stable, repeatable, and cost-effective. These developments elucidate fundamental switching principles and provide a scalable approach for fabricating multifunctional organic memories, making them appealing alternatives for intelligent, adaptable systems, reconfigurable storage, and adaptive computing.