Resistive Switching and Modulation of Pb(Zr_0.4Ti_0.6)O₃/Nb:SrTiO₃ Heterostructures

Abstract

In this work, epitaxial Pb(ZrTi)O (PZT) thin films with different thicknesses were deposited on Nb-doped SrTiO (NSTO) single-crystal substrates by chemical solution deposition (CSD), and their ferroelectric resistive switching behaviors were investigated. The results showed that the maximum ON/OFF ratio up to 850 could be obtained in the PZT/NSTO heterostructure with the 150 nm thick PZT film. On the basis of the Schottky-Simmons model and the modified semiconductor theory, we also evaluated the interfacial built-in field and the depletion layer at the PZT/NSTO interface, which can be modulated strongly by the ferroelectric polarization, but are independent of the thickness of the PZT thin films. It is clear that the ferroelectric resistive switching is related to the ferroelectric polarization and modulated by the thickness of ferroelectric films. Therefore, there is an optimal thickness of the PZT film for the maximum ON/OFF ratio due to the ferroelectricity and conductivity mutually restricting. It can be expected that by adjusting the ferroelectricity and conductivity of the ferroelectric thin film and its thickness, the maximum switching ratio can be further improved.

Configurable Resistive Response in BaTiO3 Ferroelectric Memristors via Electron Beam Radiation

“…Notably, under the tested conditions of EBD and accelerating voltage, the resistance of BTO varied quasi‐continuously over two orders of magnitude. The variation in BTO resistance driven by e‐beam effect is lower than the ON/OFF ratio of about 10 3 achieved in other memristive devices with similar thickness of the FE material 17,27,42. However, the values of voltage involved in the present I / V curves are about one order of magnitude lower than in those reports.…”

“…The present quest in the field of NC is to implement hardware and materials capable of reproducing the extensive capabilities in terms of learning, adaptability, and low‐power operation of the human brain. In this regard, there has been a growing interest with respect to the opportunities offered by the exceptional functional properties of ferroelectric (FE) oxides 11–18…”

“…For each value of EBD, the voltage was applied under the same conditions using a limited range of ±1 V. In this way, it was possible to extract the information related to the influence of EBD minimizing possible effects related to the applied voltage. Indeed, the variation of the applied voltage is the commonly established way to control the memristive response of FE oxides 11,12,17…”

Resistive Switching Behavior in Ferroelectric Heterostructures

“…d) ON/OFF ratios as a function of the Pb(Zr 0.4 Ti 0.6 )O 3 thickness. All panels reproduced with permission . Copyright 2016, American Chemical Society.…”

“…Moreover, the domain walls were found to be less conductive than the domains of each polarization direction, regardless of the thickness, by conduction atomic force microscopy (CAFM). The states of vertical domains are not tested in this work, and the conclusions may [24] Copyright 2016, American Chemical Society. be incomplete.…”