Schottky Barrier Control of Self-Polarization for a Colossal Ferroelectric Resistive Switching

Biaohong Huang; Xuefeng Zhao; Xiaoqi Li; Lingli Li; Zhongshuai Xie; Di Wang; Dingshuai Feng; Yuxuan Jiang; Jingyan Liu; Yizhuo Li; Guoliang Yuan; Zheng Han; Tula R Paudel; Guozhong Xing; Weijin Hu; Zhidong Zhang

doi:10.1021/acsnano.3c01548

Schottky Barrier Control of Self-Polarization for a Colossal Ferroelectric Resistive Switching

ACS Nano. 2023 Jul 11;17(13):12347-12357. doi: 10.1021/acsnano.3c01548. Epub 2023 Jun 26.

Authors

Biaohong Huang^{1

2}, Xuefeng Zhao³, Xiaoqi Li^{1

2}, Lingli Li^{1

2}, Zhongshuai Xie⁴, Di Wang³, Dingshuai Feng^{1

2}, Yuxuan Jiang^{1

2}, Jingyan Liu^{1

2}, Yizhuo Li¹, Guoliang Yuan⁴, Zheng Han¹, Tula R Paudel⁵, Guozhong Xing³, Weijin Hu^{1

2}, Zhidong Zhang¹

Affiliations

¹ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences (IMR, CAS), Shenyang, 110016, China.
² School of Material Science and Engineering, University of Science and Technology of China (USTC), Shenyang, 110016, China.
³ Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029; and University of Chinese Academy of Sciences, Beijing, 100049, China.
⁴ School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
⁵ Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, United States.

PMID: 37358564
DOI: 10.1021/acsnano.3c01548

Abstract

Controlling the domain evolution is critical both for optimizing ferroelectric properties and for designing functional electronic devices. Here we report an approach of using the Schottky barrier formed at the metal/ferroelectric interface to tailor the self-polarization states of a model ferroelectric thin film heterostructure system SrRuO₃/(Bi,Sm)FeO₃. Upon complementary investigations of the piezoresponse force microscopy, electric transport measurements, X-ray photoelectron/absorption spectra, and theoretical studies, we demonstrate that Sm doping changes the concentration and spatial distribution of oxygen vacancies with the tunable host Fermi level which modulates the SrRuO₃/(Bi,Sm)FeO₃ Schottky barrier and the depolarization field, leading to the evolution of the system from a single domain of downward polarization to polydomain states. Accompanied by such modulation on self-polarization, we further tailor the symmetry of the resistive switching behaviors and achieve a colossal on/off ratio of ∼1.1 × 10⁶ in the corresponding SrRuO₃/BiFeO₃/Pt ferroelectric diodes (FDs). In addition, the present FD also exhibits a fast operation speed of ∼30 ns with a potential for sub-nanosecond and an ultralow writing current density of ∼132 A/cm². Our studies provide a way for engineering self-polarization and reveal its strong link to the device performance, facilitating FDs as a competitive memristor candidate used for neuromorphic computing.

Keywords: BiFeO3; Schottky barrier; ferroelectric diode; oxygen vacancy; self-polarization.