High-Performance MoTe₂ Vertical Memristors Featuring Semi-Metallic Antimony Electrodes for an Expanded Memory Window and Improved Stability

MoTe2 exhibits the smallest energy difference between its various phases among all transition metal dichalcogenides, making it a promising candidate for phase-change resistive switching (RS) devices. However, its low on/off current (ION/OFF) ratio limits practical applications. In this study, we developed a MoTe2 vertical memristor using semimetallic Sb as the contact electrode, significantly enhancing the RS ratio by more than an order of magnitude. The Sb-contact MoTe2 memristors exhibit excellent endurance, maintaining a high ION/OFF ratio and stable operating voltages for over 100 cycles in DC endurance tests. Additionally, they exhibit stable bipolar resistive switching with a cycling endurance exceeding 2 × 105, a high ION/OFF ratio, and fast switching speeds of 50 ns for SET and 70 ns for RESET. By employing Sb-based MoTe2 vertical memristors as artificial synapses, we achieved excellent long-term potentiation (LTP) and long-term depression (LTD) characteristics. As a result, the MoTe2 device exhibits an enhanced dynamic range (∼10), superior linearity (0.19 for LTP and −0.16 for LTD), and high-accuracy handwritten digit recognition (>91%). This work presents an effective strategy for improving the performance of MoTe2 vertical memristors, paving the way for their application in advanced neuromorphic computing systems.