Towards low-temperature processing of lead-free BZT thin films for high-temperature energy storage performance

Abstract:

In this work, lead-free BaZr0.35Ti0.65O3 (BZT) thin films were grown on silicon by using pulsed laser deposition. The phase structures of the BZT thin films were controlled via the deposition temperature, and their effects on the breakdown strength and energy-storage performance were systematically investigated. Our results indicate that the BZT thin films deposited at a low temperature of 450 °C have a paraelectric phase and display the highest recoverable energy density of 121.2 J/cm3 and a medium energy efficiency of 88.2%. The ultrahigh energy storage achieved is mainly due to the remarkable improvement in the breakdown strength and the slimmer and slanted polarization hysteresis loop. Moreover, the BZT thin films demonstrate excellent thermal stability across a wide temperature measurement range (25–200 °C) and a superior fatigue endurance of up to 1010 switching cycles even under a high temperature measurement of 200 °C. This work provides a simple and effective way of improving the energy storage properties and stable performance of dielectric thin films for application in harsh environments.