Engineering Titanium Dioxide/Titanocene-Polysulfide Interface for Flexible, Optical-Modulated, and Thermal-Tolerant Multilevel Memristor

Abstract

Multifunctional memristors with a high memory density, low power consumption, flexibility, programmability, and environmental robustness are essential for next-generation memories. In this work, a titanocene-polysulfide complex (Cp₂TiS₅) with strong S···S interactions and hydrogen bonds was synthesized and integrated with TiO₂ to create a novel Cu/TiO₂/Cp₂TiS₅/Ag memristor. This device shows bipolar nonvolatile memory performance with a remarkable ON/OFF ratio (10^4.8), low switching voltages (V_SET, −0.16 V; V_RESET, +0.15 V), and low power consumption (2.7 × 10^–4 μW). It exhibits multilevel memory behavior, flexibility, optical modulation (V_SET decreases from −1.35 to −0.17 V with decreasing irradiation wavelength), and thermal tolerance (up to 200 °C). The electron-rich Cp₂TiS₅ layer protects the Ag-CFs, while TiO₂’s oxygen vacancies and unsaturated Ti atoms interact with sulfur from Cp₂TiS₅, lowering the Schottky barrier and facilitating charge transport. This work offers promising opportunities in flexible memristive devices for neuromorphic computing under extreme conditions.