The plasticity of synaptic memristor based on 2D-MoS2 thin film prepared in large-scale by a PLD-assisted CVD method

Abstract

Two-dimensional MoS2 film was directly grown via a two-step chemical vapour deposition (CVD) method in a large-scale on a phosphorus doped silicon substrate, where a precursor of Mo was Pre-deposited by pulsed laser deposition (PLD) to ensure the homogeneity of Mo source. The film was confirmed to be dense, uniform and continuous nanocrystalline of MoS2 by the characterization of XRD, Raman, SEM, TEM and XPS. Then MoS2 film was employed as the channel materials to fabricate the memristor with lateral structure of Cu/MoS2/Cu. Consequently, the devices show stable nonvolatile resistance switching characteristics, such as low operating voltages, repeated cyclic sweeps (600 times) without decrease and long retention time (>104 s). Such mechanism of resistive switching can be attributable to the space-charge limited conduction dominated by defects. Importantly, a variety of biological synaptic functions, such as synaptic potentiation, depression and repetitive learning processes, are effectively simulated. Furthermore, the relationships between the resistance state and the parameters of pulse sequence were explored based on MoS2 thin film memristors. This research provides a feasible method for manufacturing MoS2 based on memristor, which is used for information and computing applications in neural morphological devices.