An\nOxide Schottky Junction Artificial Optoelectronic\nSynapse

Abstract

The\nrapid development of artificial intelligence techniques and\nfuture advanced robot systems sparks emergent demand on the accurate\nperception and understanding of the external environments <i>via</i> visual sensing systems that can co-locate the self-adaptive\ndetecting, processing, and memorizing of optical signals. In this\ncontribution, a simple indium–tin oxide/Nb-doped SrTiO₃ (ITO/Nb:SrTiO₃) heterojunction artificial optoelectronic\nsynapse is proposed and demonstrated. Through the light and electric\nfield co-modulation of the Schottky barrier profile at the ITO/Nb:SrTiO₃ interface, the oxide heterojunction device can respond to\nthe entire visible light region in a neuromorphic manner, allowing\nsynaptic paired-pulse facilitation, short/long-term memory, and “learning-experience”\nbehavior for optical information manipulation. More importantly, the\nphotoplasticity of the artificial synapse has been modulated by heterosynaptic\nmeans with a sub-1 V external voltage, not only enabling an optoelectronic\nanalog of the mechanical aperture device showing adaptive and stable\noptical perception capability under different illuminating conditions\nbut also making the artificial synapse suitable for the mimicry of\ninterest-modulated human visual memories.