Highly flexible memristive devices based on MoS2 quantum dots sandwiched between PMSSQ layers

Abstract

This paper reports a facile, cost effective method that uses an aqueous hydrothermal process for synthesizing two-dimensional molybdenum disulphide (MoS₂) monolayer quantum dots (QDs) and their potential applications in flexible memristive devices. High-resolution transmission electron microscopy and atomic force microscopy images confirmed that the diameters of the synthesized MoS₂ QDs with irregular shapes were in the range between 3 and 6 nm; their thicknesses were confirmed to lie between 1.0 and 0.8 nm, a clear indication that a monolayer of MoS₂ QDs had been synthesized. Photoluminescence (PL) and time-resolved PL spectra of the MoS₂ QDs revealed a strong emission in the blue region with a slower decay constant. Memristive devices fabricated by incorporating MoS₂ QDs between poly(methylsilsesquioxane) ultrathin layers, which had been deposited on poly(ethylene terephthalate), demonstrated a high ON–OFF current ratio of ∼10⁴, stable retention, and excellent endurance in the relaxed state; these devices were also demonstrated to function properly during bending and in a bent state. The flexible memristive devices demonstrated an OFF state with a very low current of 10⁻⁶ A. These results clearly show that ultrathin two-dimensional QDs have promising applications in high-performance flexible memristive devices.