Robust Metal and Semiconductor Phase Transition Memristor Using Ag‐Intercalated Transition Metal Dichalcogenide

Abstract Metal (1T/1T')‐semiconductor (2H) phase transition memristors (PTMEMs) based on intercalated alkali metal ions (Li + ) in transition metal dichalcogenides (TMDs) exhibit excellent electrical properties, including heterosynaptic plasticity. However, the low stability of Li + ions limits retention and on/off ratios of the PTMEMs. Here, a phase transition in MoTe 2 induced by intercalated Ag + ions is demonstrated for the first time, enabling robust memristor operation. The migration of Ag + ions, controlled by voltage biases, clearly realizes reversible 2H‐1T/1T’ phase transitions, as revealed by transmission electron microscopy, X‐ray photoelectron spectroscopy, and Raman mapping. The memristive mechanism of MoTe 2 shifts from doping (4–8 h) to phase transition (12 h) as Ag intercalation time increases, achieving a 200 000 on/off ratio at a 4 nm thickness. MoTe 2 exhibits the most evident phase transition due to its low transition barrier (0.84) compared to other TMDs (>1.22). Intercalated Ag + ions provide outstanding memristive performance over Li + ions, with a 100 times higher on/off ratio, 300 times better retention, and 8 times lower non‐linearity (β Ag = 0.5–0.6, β Li = 4.0). Ag + MoTe 2 PTMEM achieves 91.7% accuracy in MNIST recognition, surpassing the 81.7% accuracy of Li + MoS 2 PTMEM. These findings demonstrate that Ag + MoTe 2 PTMEM holds great potential for advanced memory‐based neural network applications.