Tuning of Photoinduced Resistive Switching Characteristics of MoS2/PVA Photomemristor via Ultrasonication

Abstract

In the present study, we have used a simple, cost effective and environment friendly hydrothermal method to synthesize the few layered MoS₂ nanosheets (NSs). We have synthesized MoS₂/PVA nanocomposites (NCPs) with four different concentrations of MoS₂ (0.1 wt%, 0.5 wt%, 1 wt% and 1.5 wt%) within the polymer matrix by utilizing the chemical route In-situ method. The structural and morphological investigations have been conducted with the help of X-ray diffraction (XRD) and Field Effect Scanning Electron Microscopy (FESEM), respectively. The UV-visible (UV-Vis) spectroscopy has been employed to study the linear absorption spectra and to calculate the band gap value using Tauc’s plot method of the as synthesized few layered MoS₂ NSs. The calculated band gap of MoS₂ NSs comes out to be 1.62 eV. Photoluminescence (PL) spectroscopy has been employed to record the linear emission characteristics of MoS₂ NSs. High Resolution Transmission Electron Microscopy (HRTEM) have been used to calculate the particle size of synthesized MoS₂ NSs. We have fabricated a photomemristive device with architecture Ag/MoS₂-PVA/FTO with the help of a simple and cost effective drop casting method. The influence of the concentration of MoS₂ as well as the ultrasonication time duration on the performance of MoS₂/PVA based photomemristor have been studied. The cyclic I-V measurements show hysteresis and confirm the charge storage in the fabricated device. Further, we have studied the WRER sequence and endurance characteristics of the fabricated photomemristive device over 100 cycles. The maximum I_on/I_off value has been obtained in the case of 1 wt% concentration of MoS₂ within the polymer matrix for 8 hrs of sonication and it comes out to be ~ 1.68 ×10² and 3 ×10² in the absence and presence of external light source, respectively. The fabricated device is stable and reliable as confirmed by WRER sequences and endurance characteristics.