Nanoscale Insights into the Dynamics of Conductive Filament Growth/Dissolution in 2D Material-Based Memristors

2D materials have drawn widespread attention as promising candidates for electrochemical metallization (ECM) memristors. However, some critical questions related to the resistance switching (RS) behaviors of 2D material-based ECM memristors, such as the pathways of conductive filaments (CFs) growth/dissolution, the chemical composition and crystal structure of the CFs, remain largely unexplored. Herein, in situ transmission electron microscopy is employed to investigate the evolution of CFs in Ag (or Cu)/MoS₂/W ECM memristors. Contrary to the traditional ECM theory, the CFs are found to grow from the anode to the cathode and dissolve from the cathode to the anode. Notably, Ag CFs with different crystal structures and metallic sulfide-type CFs are observed in the memristors. These results provide deeper insights into the RS mechanism in 2D material-based ECM memristors and facilitate the optimization of memristive devices.