Leakage current characteristics and dielectric breakdown of antiferroelectric Pb_0.92La_0.08Zr_0.95Ti_0.05O₃film capacitors grown on metal foils

Abstract

We have grown crack-free antiferroelectric (AFE) Pb0.92La0.08Zr0.95Ti0.05O3 (PLZT) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, we applied a conductive buffer layer of lanthanum nickel oxide (LNO) on the nickel foil by chemical solution deposition prior to the PLZT deposition. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be prepared at high temperatures in air. With the AFE PLZT deposited on LNO-buffered Ni foils, we observed field-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, EAF = 260 kV cm−1, and the reverse phase transition field, EFA = 220 kV cm−1, were measured at room temperature on a ∼1.15 µm thick PLZT film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were ∼530 and ∼740, respectively, with dielectric loss <0.05 at room temperature. P–E hysteresis loop measured at room temperature confirmed the field-induced phase transition. The time-relaxation current density was investigated under various applied electric fields. The leakage current density of a 1.15 µm thick AFE PLZT film-on-foil capacitor was 5 × 10−9 A cm−2 at room temperature under 87 kV cm−1 applied field. The breakdown behaviour of the AFE PLZT film-on-foil capacitors was studied by Weibull analysis. The mean breakdown time decreased exponentially with increasing applied field. The mean breakdown time was over 610 s when a field of 1.26 MV cm−1 was applied to a 1.15 µm thick AFE PLZT film-on-foil capacitor.

Flexible antiferroelectric thick film deposited on nickel foils for high energy‐storage capacitor

“…The linear region is agreement with the mechanism of space‐charge‐limited conduction (SCLC), which could be described by the following equation:where µ is the electrical mobility, ε 0 is the dielectric constant of the vacuum, ε r is the relative dielectric constant, E is the applied field, and d is the thickness of the film . According to the SCLC mechanism, the electrical charge hopping is the primary factor of the leakage current in the AFE film grown on nickel foil . Figure F shows Weibull plot of the BDS obtained from eight samples at room temperature.…”

High energy-storage performance in Pb0.91La0.09(Ti0.65Zr0.35)O3 relaxor ferroelectric thin films

“…It was believed that three possible mechanisms were associated with the Curie-von Schweidler law: space charge trapping, relaxation time distribution, and electrical charge hopping. 26,27 The curves plotted in Fig. 9 were least square fittings of the experimental data, according to above equation.…”

Enhanced dielectric nonlinearity in epitaxial Pb0.92La0.08Zr0.52Ti0.48O3 thin films

“…3(a). 24 This is not surprising since higher permittivity is expected in the latter due to the presence of grain boundaries, which bring an additional contribution to the polarization charges. 25 The dielectric loss in the epitaxial PLZT film is as low as 0.04, which is comparable to the lowest dielectric loss of 0.035 in polycrystalline PLZT thin film.…”

“…The steady state leakage current density J s ¼ 6.2 Â 10 À8 A/cm 2 , which is a factor of three higher than 2 Â 10 À8 A/cm 2 in the polycrystalline PLZT film. 24 Normally, the polycrystalline films have a much higher resistivity as compared to their epitaxial counterparts because of much higher density of structural defects, especially grain boundaries, acting as trapping-scattering center for the free carriers, reducing their mobility in polycrystalline films. 25,26 An Agilent E4980A precision LCR Meter was used to determine the relative permittivity and dielectric loss of epitaxial PLZT film under an applied bias field.…”