SiN-based optoelectronic synaptic devices: enhancing future cognitive computing systems†

In this study, an optoelectronic synaptic device based on an indium tin oxide/SiN/TaN structure was fabricated for bio-inspired computing. Under light exposure, the device exhibits excitatory postsynaptic current, which affords various synaptic functionalities. This device mimics the paired-pulse facilitation characteristics of short-term memory and the five essential functions of a human nociceptor: threshold, relaxation, no-adaptation, hyperalgesia, and allodynia. Additionally, it demonstrates heterosynaptic associative long-term potentiation between two inputs and emulates associative learning behavior based on Pavlov's conditioning experiment. These results demonstrate the potential of SiN-based devices as optoelectronic synapses for cognitive learning.