Observing resistive switching behaviors in single Ta2O5 nanotube-based memristive devices. (June 2022)

• Record Type: Journal Article
• Authors: Liu, C.-J.; Lo, H.-Y.; Hou, A.-Y.; Chen, J.-Y.; Wang, C.-H.; Huang, C.-W.; Wu, W.-W.
• Is Part Of: Materials today nano. Volume 18(2022)
• Publication Date: 2022-06
• Subjects: Ta2O5 nanotube -- Ion diffusion -- Resistive switching mechanism -- In-situ TEM -- EELS; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Nanoscience; Nanotechnology -- Periodicals; Periodicals; Periodical; Electronic journals; Electronic journals; 620.5
• DOI: 10.1016/j.mtnano.2022.100212
• Languages: English
• ISSNs: 2588-8420

Abstract

Abstract: Recently, one-dimensional (1D) metal oxide nanostructured materials have attracted considerable attention owing to their appealing properties and functionalities. In previous studies, 1D metal oxide materials have been widely applied to electronic components; among them, resistive switching memristive devices are one of the most promising applications. The resistive switching mechanism in thin-film dielectric layers is widely explored, but understanding of that in 1D materials is insufficient. Moreover, a direct evidence regarding the switching behavior resulting from the formation and dissolution of conductive filaments is still lacking. In this study, a single Ta2 O5 nanotube (NT) was fabricated as an Ag/Ta2 O5 NT/Ag device, and its electrical properties were examined, which demonstrated a stable resistance state with a large memory window of approximately 10 7 . The in-situ transmission electron microscopy (TEM), high-resolution TEM, energy dispersive spectroscopy techniques and electron energy loss spectroscopy (EELS) were used to establish a unique resistive switching mechanism in such devices for the first time. In addition, the crystallinity of the Ta2 O5 NTs was well-controlled through rapid thermal annealing and furnace. The relationship between crystallinity and electrical properties was investigated. Oxygen vacancies play a crucial role in resistance switching, and thus, their amounts were determined using EELS. Therefore, the established mechanism revealed the dynamic behavior of Ta2 O5 NTs in memristive devices, which allows the exploration of a wide range of NT materials for memory applications. Graphical abstract: A single Ta2 O5 nanotube (NT) was fabricated as Ag/Ta2 O5 NT/Ag memristive device demonstrating both volatile and non-volatile memory properties, such as unipolar resistive switching and selector function. This study provides not only the switching mechanism of single Ta2 O5 NT-based devices, but also exploration of wide range of NT materials for memory applications. Image 1 Highlights: Resistive switching mechanism of the single Ta2 O5 nanotube-based memristive device was firstly introduced by in-situ TEM The Ag/Ta2 O5 NT/Ag device performed outstanding electrical properties. The conductive filaments were composed of a series of silver nanoparticles formed on the surface of the Ta2 O5 NT and current through the device was governed by a series of tunneling. From EELS analysis, forming voltage became larger with the decrease of oxygen vacancies, and it was also influenced by the grain size of the NT. The devices exhibited two memory behaviors, as a unipolar resistive switch and a selector function.