Light Sensing Artificial Synapse Based on Zinc Oxynitride for Neuromorphic Applications

In this letter, we have demonstrated an optoelectronic synapse based on zinc oxynitride (ZnON) thin films. Unlike other amorphous oxide semiconductors, which respond mostly to UV, these ZnON films respond to blue region of the visible spectrum as well. The essential synaptic functions of the human brain, such as, sensory memory, short-term memory, long-term memory, duration-time-dependent plasticity, and paired pulse facilitation (PPF), have been demonstrated using ZnON. The fabricated ZnON synapse shows a PPF index of 140% for UV and 130% for blue light, respectively. The feasibility of utilizing these synaptic devices for neuromorphic computing has been successfully demonstrated by implementing
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Boolean logic in a neural network circuit.