Resistive Switching in a MoSe2-Based Memory Device Investigated Using Conductance Noise Spectroscopy

Resistive random access memory (RRAM) devices are widely considered promising candidates for future memory and logic applications. Though their excellent performances have been reported over the years, resistive switching due to various charge conduction mechanisms is still being debated. Here, we report systematic investigations on resistive switching in a MoSe2-based nonvolatile bipolar memory device by measuring current-voltage characteristics and using low-frequency conductance noise spectroscopy in both low and high resistive states. The memory device was fabricated in a metal-insulator-metal configuration by mixing MoSe2 nanoflakes in a poly(methyl methacrylate) (PMMA) matrix sandwiched between the top and bottom electrodes. The device shows an appreciable retention capacity and long cycle endurances in the low resistive state (LRS)/high resistive state (HRS) in repeated measurement cycles. The low-frequency conductance fluctuation power spectra show 1/f noise characteristics in the low resistive state and 1/f(2) behavior in the high resistive state. The 1/f(2) characteristics of the noise power spectra indicate the presence of random telegraphic noise. The stochastic analysis of the current fluctuation in the high resistive state further confirms that the enhanced random telegraphic noise originates from the transport of charge carriers by trap-assisted tunneling in the MoSe2@PMMA matrix.