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 [Δ<i>V</i>(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.