Intrinsic and interfacial effect of electrode metals on the resistive switching behaviors of zinc oxide films

• Published in: Nanotechnology Vol. 25; no. 42; p. 425204
• Main Authors: Xue, W H, Xiao, W, Shang, J, Chen, X X, Zhu, X J, Pan, L, Tan, H W, Zhang, W B, Ji, Z H, Liu, G, Xu, X-H, Ding, J, Li, R-W
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 24.10.2014; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Devices; Electric potential; Electrodes; Electronegativity; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; ionic size; Optimization; Physics; resistive switching; roughness; Switching; Voltage; Zinc oxide; Thin films; Interfaces; Electrical properties; Thin layer electrode; Roughness; Zinc oxide; Electronegativity; Sandwich structures; Switching; Optimization
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/25/42/425204

Exploring the role of electrode metals on the resistive switching properties of metal electrode oxide metal electrode sandwiched structures provides not only essential information to understand the underlying switching mechanism of the devices, but also useful guidelines for the optimization of the switching performance. A systematic study has been performed to investigate the influence of electrodes on the resistive switching characteristics of zinc oxide (ZnO) films in this contribution, in terms of both the intrinsic and interfacial effects. It has been found that the low-resistance state resistances ( LRS) of all the investigated devices are below 50 , which can be attributed to the formation of highly conductive channels throughout the ZnO films. On the other hand, the high-resistance state resistances ( HRS) depend on the electronegativity and ionic size of the employed electrode metals. Devices with electrode metals of high electronegativity and large ionic size possess high HRS values, while those with electrode metals of low electronegativity and small ionic size carry low HRS values. A similar trend of the set voltages has also been observed, while the reset voltages are all distributed in a narrow range close to ±0.5 V. Moreover, the forming voltages of the switching devices strongly depend on the roughness of the metal ZnO and or ZnO metal interface. The present work provides essential information for better understanding the switching mechanism of zinc oxide based devices, and benefits the rational selection of proper electrode metals for the device performance optimization.