Enhanced energy-storage performance of all-inorganic flexible bilayer-like antiferroelectric thin film via using electric field engineering
A novel all-inorganic flexible bilayer-like Pb0.99Nb0.02(Zr0.55Sn0.40Ti0.05)0.98O3 (PNZSTBL) thin film with the same chemical composition is designed to enhance energy-storage performance. The PNZSTBL thin film that consists of a large polarization (PNZSTLP) top layer and a high electric breakdown field (PNZSTHE) bottom layer are deposited on flexible mica by controlling sputtering pressure. The dislocations in such bilayer-like film can be repressed effectively owing to the identical chemical composition. Most importantly, the PNZSTBL exhibits complementary advantages of the PNZSTHE and PNZSTLP films based on the electric field amplifying effect and interlayer coupling. An enhanced recoverable energy-storage density (Wrec) of 39.35 J cm-3 is achieved in PNZSTBL thin film, which is 70% higher than that of the single-layer PNZSTLP. Meanwhile, flexible PNZSTBL thin film enjoys an outstanding stability in terms of frequency (10–5000 Hz) and temperature (30–170 °C). In addition, flexible PNZSTBL thin film shows a favorable mechanical cycling endurance after repeated bending 1200 times for a 3.5 mm tensile radius. This work offers a fresh strategy to design perspective bilayer-like dielectric thin film for optimizing energy-storage performances of materials.