CsSnI3 optoelectronic synaptic device for biomimetic visual nociception and sound perception

PEACl and SnF 2 additive engineering effectively regulated the crystallization behavior and defect states of CsSnI 3 films. • Biomimetic nociceptive features including threshold, sensitization, desensitization, and non-adaptation were successfully emulated. • Multimodal neuromorphic functionalities including image mapping and sound perception were successfully demonstrated. With the accelerated improvement of neuromorphic computing and artificial intelligence, optoelectronic synapses have received extensive attention for applications in artificial vision and brain-inspired perceptual systems. However, integrating high photosensitivity, stable synaptic plasticity, and advanced visual perception into a single platform remains challenging. Herein, CsSnI₃ perovskite films with high crystallinity were successfully fabricated through a low-temperature solution process assisted by PEACl and SnF₂ additives. Subsequently, an ITO/CsSnI₃/Ag optoelectronic synaptic device was constructed. Under optical stimulation, reliable photo-induced synaptic behaviors were achieved, including excitatory postsynaptic current, paired-pulse facilitation, and multilevel conductance modulation. Owing to its stable optoelectronic synaptic behavior, the device successfully replicated visual nociceptive responses, such as threshold activation, sensitization, desensitization, and non-adaptive behavior. Moreover, sound recognition was achieved through the combined modulation of frequency, voltage and illumination intensity, and a quantitative correlation between the recognition factor and the postsynaptic current was also developed. This work provides a feasible strategy for constructing lead-free perovskite optoelectronic synapses toward artificial vision and neuromorphic perception applications. Download: Download high-res image (315KB) Download: Download full-size image