Enhanced memristor performance via coupling effect of oxygen vacancy and ferroelectric polarization

• Published in: Journal of materials science & technology 2024-02, Vol.171, p.139-146
• Main Authors: Yue, Zhi Yun, Zhang, Zhi Dong, Wang, Zhan Jie
• Format: Article
• Language: English
• Subjects: Ca-doped pzt; Ferroelectric memristor; Ferroelectric polarization; Oxygen vacancies; Resistive switching
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2023.07.007

•High performance of the ferroelectric memristor is inseparable from the ferroelectricity and leakage current.•The ferroelectricity and electricity of ferroelectric thin films can be improved simultaneously by doping low-content ca ions to increase the resistive switching (RS) performance.•The difference in the radius of ca ions and pb ions and oxygen vacancies affect the tetragonality (c/a), which changes the ferroelectric polarization properties.•The RS on/off ratio reached about 2.5 × 105 in the PCZT/NSTO heterostructures doped with 1 mol% ca. As a new type of nonvolatile memory, the resistive memristor has broad application prospects in information storage and neural computing based on its excellent resistive switching (RS) performance. At present, it is still a great challenge to improve both ferroelectric polarization and leakage current to achieve a high RS on/off ratio of ferroelectric memristors. Herein, epitaxial Pb(Zr0.40Ti0.60)O3 (PZT) thin films with low content Ca doping were deposited on the Nb:SrTiO3 substrate to prepare PCZT/NSTO heterostructures and their RS behaviors were studied. The research findings show that compared with pure PZT films, the ferroelectric polarization of 1-mol%-Ca-doped PZT film is slightly improved, while the leakage current is increased by three orders of magnitude. Therefore, the RS on/off ratio reaches 2.5 × 105, about three orders of magnitude higher than pure PZT films. The theoretical analysis reveals that the RS behavior of PCZT/NSTO heterostructures is controlled by the PCZT/NSTO interfacial barrier and the space charge-limited current mechanism. Our results demonstrate that the ferroelectricity and electricity of ferroelectric thin films can be improved simultaneously by doping low-content Ca ions to increase the RS performance, which provides a good reference for the development of high-performance ferroelectric memristor devices. [Display omitted]