Effect of argon-oxygen ratio on dielectric and energy storage properties of Ba(Zr0.35Ti0.65)O3 thin films

Lead-free Ba(Zr0.35Ti0.65)O3(short as BZT35) ferroelectric thin films are prepared by RF magnetron sputtering on Pt/Ti/SiO2/Si substrates. Effects of argon-to-oxygen (short as Ar/O2) ratios on phase transition, dielectric and energy storage properties are studied. The research found that all thin films are perovskite structures. With the decrease of Ar/O2, the oxygen vacancies (OVs) in the film are effectively suppressed, which promotes the film to obtain a larger dielectric constant, smaller dielectric loss, and lower leakage current density. The BZT35 film prepared under Ar/O2 = 40:10 has excellent energy storage density (48.03 J/cm3) and efficiency (87.7%) because of its elongated hysteresis loop, the largest polarization difference (Delta P = 22.91 mu C/cm2), higher breakdown field strength (Eb = 4.50 MV/cm) and lower leakage current density (J = 2.3 x 10_ 5 A/cm2) and high power density of 7.94 MW/cm3. In addition, the BZT35 film also has excellent frequency stability (500 Hz-20 kHz). These excellent properties show that BZT35 has very broad application prospects in energy storage.

Automated summary

In this study, lead-free BZT35 ferroelectric thin films were prepared by RF magnetron sputtering, and the effects of argon-to-oxygen ratios on their properties were investigated. The results showed that reducing the Ar/O2 ratio effectively suppressed oxygen vacancies and improved the dielectric properties and leakage resistance of the films. The BZT35 film prepared under Ar/O2 = 40:10 exhibited excellent energy storage performance and frequency stability.