Effect of crystallization temperature on energy-storage density and efficiency of lead-free Bi0.5(Na0.8K0.2)0.5TiO3 thin films prepared by solegel method

• Main Authors: Nguyen, Dang Co, Le, Viet Cuong, Bui, Dinh Tu, Pham, Duc Thang, Luong, Xuan Dien, Vu, Ngoc Hung, Ngo, Duc Quan
• Format: Article
• Language: English
• Published: Elsevier 2019
• Subjects: Energy-storage; Ferroelectric; Solegel; Film; Lead-free
• Online Access: http://repository.vnu.edu.vn/handle/VNU_123/67737; https://doi.org/10.1016/j.jsamd.2019.04.008
• Institution: Vietnam National University, Hanoi

Lead-free Bi0.5(Na0.80K0.20)0.5TiO3 (BNKT) ferroelectric films were synthesized on Pt/Ti/SiO2/Si substrates via the chemical solution deposition. The influence of the crystallization temperature on the microstructures, the ferroelectric and energy-storage properties of the films was investigated in detail. The results showed that the BNKT films have reached the well crystallized state in the single-phase perovskite structure at 700 C. Ferroelectric and energy-storage properties of the films were significantly enhanced by increasing the crystallization temperature. The remnant polarization (2Pr) and maximum polarization (2Pm) reached the highest values of 18.4 mC/cm2 and 61.2 mC/cm2, respectively, under an applied electric field of 300 kV/cm. Thanks to the strong enhancement in 2Pm and the large Pmax - Pr value, the highest energy-storage density (Jreco) and efficiency of 2.3 J/cm3 and 58.2%, respectively, were obtained. These results indicate that the BNKT films have application potentials in advanced capacitors. © 2019 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi