High energy storage performance of (Na0.5Bi0.5)TiO3 thin film induced by stress engineering

Abstract

Relaxor ferroelectrics are the primary candidates for high-performance energy storage dielectric capacitors. Here, stress engineering, which was realized by optimizing the lattice mismatch between (Na0.5Bi0.5)TiO3 film and SrRuO3/(La0.5Sr0.5)CoO3 bottom electrodes, was used to enhance the energy storage performance of (Na0.5Bi0.5)TiO3 relaxor ferroelectric film. As a result, in-plane compressive stress caused by the lattice mismatch between (Na0.5Bi0.5)TiO3 film and (La0.5Sr0.5)CoO3 bottom electrode leads to a large Wrec of 45.7 J/cm3 with η of 79.4% at 2000 kV/cm in (Na0.5Bi0.5)TiO3 film, which is 54.4% higher than that of (Na0.5Bi0.5)TiO3 film with in-plane tensile stress. In addition, the Wrec of (Na0.5Bi0.5)TiO3 film with in-plane compressive stress shows good thermal stability and frequency stability with variations of 5.8% at 30–120 °C and 6.9% at 0.2–20.0 kHz. This work may provide some new perspectives for the design of dielectric capacitors with high energy storage performance.

Keywords

• Energy storage performance
• (Na0.5Bi0.5)TiO3
• Film
• Stress engineering