Energy Storage and Leakage Current Characteristics of Low-Temperature-Derived Pb<sub>0.8</sub>La<sub>0.1</sub>Ca<sub>0.1</sub>Ti<sub>0.975</sub>O<sub>3</sub> Thin Films Tailored by an Annealing Atmosphere
Hanfei Zhu, Guoqiang Feng, Xiaolong Chen, Lang Xiao, Huali Liu, Jun Ouyang
Abstract
Sol–gel-derived (100)-textured Pb0.8La0.1Ca0.1Ti0.975O3 (PLCT) thin films were prepared on Pt/Ti/SiO2/Si(100) substrates at a low temperature of 450 °C. Modification of annealing atmospheres, i.e., O2, air, and N2, on the electrical properties of PLCT thin films was focused on in this work, especially the energy storage and leakage current characteristics. In contrast to some secondary phases, such as PbOx and pyrochlore phase, detected in the PLCT films annealed in air and N2, a phase-pure PLCT thin film was achieved when subjected to O2 annealing. In addition, a significant influence of the annealing atmosphere on the leakage current characteristics of PLCT films was revealed and the distinct current density–electric field (J–E) behaviors were fitted to three charge transport models: Ohmic conduction, modified Schottky emission, and Fowler–Nordheim tunneling. Importantly, unlike the PLCT thin films annealed in air and N2 that exhibited poor P–E hysteresis loops, a slim, tilted P–E loop with a Pmax of 94.5 μC/cm2 and a Pr of 11.5 μC/cm2 was obtained in the PLCT thin film annealed in O2. This feature endows it excellent energy storage capacity with a high recoverable energy density (Wre ∼ 21.9 J/cm3) and efficiency of η ∼ 65.6%, showing great potential in high-performance dielectric capacitors.