CuSbS₂-Based Near-Infrared Optoelectronic Synaptic Memristor: Toward Biomimetic Applications with Superior Synaptic Plasticity

Emerging near-infrared (NIR) optoelectronic synaptic devices, which enable parallel perception and memorization of information, play a pivotal role in developing high-efficiency neuromorphic computing systems with visual perception and complex learning capabilities. Here, CuSbS2 is used in an innovative method to achieve an artificial NIR optoelectronic synapse. This CuSbS2 memristor not only exhibits stable nonvolatile resistive switching behaviors, featuring low operating voltages (-0.69/0.68 V) with variations [ΔV(σ)/μ] both less than 13% and long retention time exceeding 104 s, but also realizes diverse synaptic plasticity triggered by both electric signals and NIR light, with the achievement of comprehensive synaptic functionalities, including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), short-term to long-term potentiation (STP/LTP), short-term and long-term memory (STM/LTM), as well as spike-timing-dependent plasticity (STDP). Moreover, utilizing the excellent optoelectric performance of CuSbS2, neuromorphic functions of designing a high-accuracy NIR imaging system are implemented, further verifying its practical application potential. The results confirm that CuSbS2 is a highly promising candidate material for constructing NIR optoelectronic artificial synapses for advanced synaptic applications, paving a solid way for the future development of neuromorphic systems integrating sensing, memory, and processing capabilities.