Optoelectronic synapse based on Mg 0.1 Zn 0.9 O/TiO 2 heterojunction for neuromorphic computing

Optoelectronic synapses that integrate sensing and synaptic weight modulation are key enablers for brain-inspired computing. Here, we report an Mg0.1Zn0.9O/TiO2 (MZO/TiO2)-based optoelectronic synaptic device capable of emulating essential biological synaptic functions, including paired-pulse facilitation, short- and long-term plasticity, as well as potentiation and depression. While electrical stimulation alone leads to volatile synaptic responses, the introduction of 365-nm optical excitation enables nonvolatile behavior, allowing more effective emulation of learning and memory. The device further supports basic arithmetic operations and, when integrated into a LeNet-5 neural network, achieves a recognition accuracy of 96.48% on the MNIST data set. These results demonstrate a promising optoelectronic strategy for advanced neuromorphic computing systems.