Energy Storage Properties of Sol–Gel-Processed SrTiO3 Films

作者：Jinpeng Liu, Ying Wang, Xiao Zhai, Yinxiu Xue, Lanxia Hao, Hanfei Zhu, Chao Liu, Hongbo Cheng, Jun Ouyang · 发表于：Materials · 年份：2022 · DOI：10.3390/ma16010031 · 被引用次数：16 · 研究领域：Ferroelectric and Piezoelectric Materials、Dielectric materials and actuators、Acoustic Wave Resonator Technologies

Dielectric films with a high energy storage density and a large breakdown strength are promising material candidates for pulsed power electrical and electronic applications. Perovskite-type dielectric SrTiO3 (STO) has demonstrated interesting properties desirable for capacitive energy storage, including a high dielectric constant, a wide bandgap and a size-induced paraelectric-to-ferroelectric transition. To pave a way toward large-scale production, STO film capacitors were deposited on Pt(111)/Ti/SiO2/Si(100) substrates by the sol–gel method in this paper, and their electrical properties including the energy storage performance were studied as a function of the annealing temperature in the postgrowth rapid thermal annealing (RTA) process. The appearance of a ferroelectric phase at a high annealing temperature of 750 °C was revealed by X-ray diffraction and electrical characterizations (ferroelectric P-E loop). However, this high dielectric constant phase came at the cost of a low breakdown strength and a large hysteresis loss, which are not desirable for the energy storage application. On the other hand, when the RTA process was performed at a low temperature of 550 °C, a poorly crystallized perovskite phase together with a substantial amount of impurity phases appeared, resulting in a low breakdown strength as well as a very low dielectric constant. It is revealed that the best energy storage performance, which corresponds to a large breakdown strength and a medium dielectr...