All oxide based flexible multi-folded invisible synapse as vision photo-receptor

• Published in: Scientific reports Vol. 13; no. 1; p. 1454
• Main Authors: Chen, Ping-Xing, Panda, Debashis, Tseng, Tseung-Yuen
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.01.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166; 639/925; Humanities and Social Sciences; Long-term depression; Long-term potentiation; multidisciplinary; Nonlinear systems; Photoreceptors; Random access memory; Science; Science (multidisciplinary); Senses; Zinc oxides
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-28505-3

All oxide-based transparent flexible memristor is prioritized for the potential application in artificially simulated biological optoelectronic synaptic devices. SnO x memristor with HfO x layer is found to enable a significant effect on synaptic properties. The memristor exhibits good reliability with long retention, 10 4  s, and high endurance, 10 4 cycles. The optimized 6 nm thick HfO x layer in SnO x -based memristor possesses the excellent synaptic properties of stable 350 epochs training, multi-level conductance (MLC) behaviour, and the nonlinearity of 1.53 and 1.46 for long-term potentiation and depression, respectively, and faster image recognition accuracy of 100% after 23 iterations. The maximum weight changes of -73.12 and 79.91% for the potentiation and depression of the synaptic device, respectively, are observed from the spike-timing-dependent plasticity (STDP) characteristics making it suitable for biological applications. The flexibility of the device on the PEN substrate is confirmed by the acceptable change of nonlinearities up to 4 mm bending. Such a synaptic device is expected to be used as a vision photo-receptor.