Layered Wide Bandgap Semiconductor GaPS₄ as a Charge‐Trapping Medium for Use in High‐Temperature Artificial Synaptic Applications

Abstract Artificial synaptic devices (ASDs) are attracting widespread attention as highly promising components for use in complex neuromorphic systems, playing crucial roles in addressing the challenges posed by the conventional von Neumann architecture. However, the instabilities of ASDs in high‐temperature environments diminish the reliabilities of the device performances, significantly inhibiting their practical application. Herein, a highly reliable 2D MoS₂/GaPS₄ ASD that maintains its functionality even after exposure to 400 °C is proposed. Moreover, due to the enhanced charge‐trapping effect of the GaPS₄ layer, the memory window expands from an initial 42 to 55 V, accompanied by a substantial on/off ratio of 10⁵, low off‐leakage current of 10⁻¹¹ A, and high number of endurance cycles (10³). The device effectively simulates various biological synaptic functions via electric and light stimulation. Notably, the high electric and light paired‐pulse facilitation indices suggest an exceptional synaptic performance. The findings introduce a novel approach to high‐temperature neuromorphic applications via defect engineering.