Studies of two-dimensional material resistive random-access memory by kinetic Monte Carlo simulations

Resistive memory based on two-dimensional (2D) tungsten disulfide (WS2), molybdenum disulfide (MoS2), and hexagonal boron nitride (h-BN) materials is studied via experiments and simulations. The influence of the active layer thicknesses is discussed, and the thickness with the best on/off ratio is found for 2D resistive random-access memory (RRAM). This work reveals fundamental differences between a 2D RRAM and conventional oxide RRAM. Furthermore, the physical parameters extracted using the kinetic Monte Carlo (KMC) model indicate that 2D materials have a lower diffusion activation energy along the vertical direction, where a smaller bias voltage and a shorter switching time can be achieved. The diffusion activation energy from the chemical vapor deposition (CVD)-grown sample is much lower than for mechanically exfoliated samples. The results suggest that MoS2 has the fastest switching speed among the three considered 2D materials.