Enhanced electrocaloric effect and energy-storage performance in PBLZT films with various Ba²⁺ content

(100)-oriented Pb_(0.90−x)Ba_xLa_0.10Zr_0.90Ti_0.10O₃ (x=0, 0.02, 0.05 and 0.11) antiferroelectric thick films were deposited on LaNiO₃/Si (100) substrates by the sol-gel process. The influences of Ba²⁺ content on the dielectric properties, electrocaloric effect (ECE), energy-storage performance and leakage current were systematically investigated. With Ba²⁺ content increasing, the temperature (T_m) corresponding to the maximum dielectric constant of the thick films was decreased, while their diffuseness was increased. The maximum ECE ∆T=18.1 °C was obtained in the thick film with x=0.05 at room temperature under ∆E=700 kV/cm. The maximum energy storage density of 42.3 J/cm³ and the corresponding efficiency of 68% was achieved in the film with x=0.11, companied by a power density of 0.53 MW/cm³, due to its high breakdown strength. In addition, a small leakage current density (<10⁻⁵ A/cm²) were attained in these films at room temperature. In conclusion, we believe that this kind of antiferroelctric thick film is a potential candidate for applications in solid cooling devices and the energy-storage systems.