Nanostructured CuAlO2@ZnO optoelectronic device for artificial synaptic applications

Abstract

Developing a neuromorphic system beyond conventional von Neumann’s architecture is necessary for future artificial intelligence applications and data-intensive computation. Optoelectronic synapses, like biological synapses, are extremely comparable in structure and operating mechanism and can learn directly from the light stimulus, making them a suitable technology for brain-inspired neuromorphic computing. Here, by constructing a core–shell structure of CuAlO2@ZnO oxide heterojunction, we have successfully fabricated the optoelectronic synaptic devices structured as ITO/CuAlO2@ZnO/ITO-glass that can be effectively motivated by light signal at visual light range. Moreover, there is an ultra-high gain of photocurrent generated in the device, resulting in an excitatory postsynaptic current (EPSC) of µA level even at a lower light intensity. In addition, the device could mimic multiple synaptic plasticities at the micro-level such as EPSC, paired-pulse facilitation (PPF), short-term plasticity (STP), spike-number-dependent plasticity (SNDP), and “advanced behaviors” of human-like innate learning and memory functions. The results presented here may serve as a new benchmark for the use of optoelectronic synaptic devices in artificial intelligence.