Revealing the potential of 2D WS ₂ memristors as an artificial synapse with resilient gradual behavior at high temperatures for neuromorphic applications

The increasing demand for future digital technologies and high-temperature neuromorphic hardware will rely on non-volatile behavior and power efficiency. High-temperature devices are crucial for space exploration and function in severe environments, such as industrial units. Two-dimensional transition metal dichalcogenides (TMDs) are known for their strong mechanical properties, which make them frontrunners for next-generation device fabrication. This paper presents an Ag/WS₂/W memristive device deposited onto a silicon substrate utilizing a direct current (DC) magnetron sputtering technique that can operate at high temperatures. The device displays steady and reliable gradual resistive switching characteristics with low set/reset switching voltages (+0.65 V/-0.55 V). Device also exhibits an excellent electrical endurance (>2500 cycles), retention time (>10⁴ s), and good cycle-to-cycle variability with low variation coefficient, confirming its consistency and robustness. Temperature-dependent current-voltage measurements were utilized to investigate the conduction behavior of the developed memristive device. The measured electrical characteristics highlighted a thermally assisted conduction process, thereby justifying the proposed switching model. Furthermore, the memristor device emulated fundamental synaptic plasticity functionalities, including long-term potentiation (LTP), long-term depression (LTD), paired-pulse facilitation (PPF), and paired-pulse depression (PPD). This study highlights 2D WS₂ as an emerging material that can serve effectively as an artificial synapse and also maintains steady operation at elevated temperatures. These findings pave the way for the realization of state-of-the-art neuromorphic computing platforms.