Giant tunneling electroresistance arising from reversible partial barrier metallization in the NaTiO3/BaTiO3/LaTiO3 ferroelectric tunnel junction. Issue 30 (27th July 2021)

• Record Type: Journal Article
• Authors: Xiao, Wei; Kang, Lili; Hao, Hua; Zhou, Yanhong; Zhang, Lei; Zheng, Xiaohong; Zeng, Zhi
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 30(2021)
• Page Start: 16349
• Page End: 16356
• Publication Date: 2021-07-27
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d1cp01767e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Based on density functional calculations, two on/off states are obtained in the NaTiO3 /BaTiO3 /LaTiO3 ferroelectric tunnel junction, leading to a TER ratio as high as 3.20 × 10 8 % due to reversible partial barrier metallization under an electric field. Abstract : Tunneling electroresistance (TER) is the change in tunneling resistance induced by ferroelectric polarization reversal in ferroelectric tunnel junctions (FTJs), and how to achieve a giant TER has always been a central topic in the study of FTJs. In this work, by considering the NaTiO3 /BaTiO3 /LaTiO3 junction with asymmetric polar interfaces as an example, we propose a novel scheme to realize a giant TER based on the reversible partial metallization of ferroelectric barrier upon the switching of ferroelectric polarization. Density functional theory calculations indicate that high on-state and low off-state conductances are obtained and the TER ratio is as high as 3.20 × 10 8 % due to the reversible partial barrier metallization, which leads to a great difference in the effective tunneling barrier widths. The reversible partial barrier metallization, accompanied by the ferroelectric polarization reversal, is driven by the parallel or anti-parallel alignment of the depolarization electrical field of the ferroelectrical barrier and a strong built-in electrical field cooperatively contributed by the asymmetric polar interfaces and the difference in the work functions of the two leads. The findings suggest a feasible scheme for constructing promising high performance FTJ memory devices by combining both asymmetric polar interfaces and substantially different work functions.