Core-shell copper nanowire-TiO2 nanotube arrays with excellent bipolar resistive switching properties

• Published in: Electrochimica acta 2019-09, Vol.316, p.133-142
• Main Authors: Chen, Jun, Wu, Yulong, Zhu, Kelin, Sun, Fang, Guo, Chungang, Wu, Xiaoling, Cheng, Guoan, Zheng, Ruiting
• Format: Article
• Language: English
• Subjects: Arrays; Artificial neural networks; Composite materials; Copper; Copper nanowire arrays; Core-shell structure; Data storage; Electroforming; Endurance; Memristors; Nanomaterials; Nanotubes; Nanowires; Resistive switching; Switching theory; Titanium dioxide; Titanium dioxide nanotube arrays
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2019.05.110

Electrochemical nanomaterial-based resistive switching devices (memristors) have recently attracted significant research interest because of their low cost and potential applications in nonvolatile data storage and artificial neural networks. In this paper, we report an electrochemical method to produce a novel memristor based on copper nanowire-titanium dioxide nanotube arrays (TNTAs), a core-shell composite material. TNTAs are fabricated using a cheap and effective electrochemical anodization method, and high-density copper nanowires are synthesized via excess-electrodeposition with a novel peeling-off strategy. This novel memristor shows both analogue and digital resistive switching properties by controlling the electroforming process. The Roff/Ron ratio of the digital memristor remains greater than 40 during 1000 consecutive I–V sweeps. The device shows good endurance over 104 pulse cycles, with an Roff/Ron ratio greater than 20. Furthermore, the data retention time can be maintained at least for 104 s. The outstanding digital resistive switching performance can be attributed to the numerous parallel copper nanowire nanoelectrodes inside the film. A novel memristor based on core-shell copper nanowire-titanium dioxide nanotube arrays (TNTAs) is successfully fabricated using a cheap and effective electrochemical method. This novel memristor shows both analogue and digital resistive switching properties. The Roff/Ron ratio of the digital memristor remains greater than 40 during 1000 consecutive I–V sweeps. The device shows good endurance over 104 pulse cycles, with an Roff/Ron ratio greater than 20. [Display omitted] •High density copper nanowires were deposited into TNTAs by a novel electrochemical based method.•The novel core-shell Cu NWs-TNTAs composite film shows both analogue and digital resistive switching properties.•The digital resistive switching ratio is more than 40 after 1000 I–V sweeps and remains more than 20 after 10000 cycles.