Structure, dielectric properties and energy storage performance of barium strontium titanate thin films prepared by spin-coating technique

摘要

Ba0.4Sr0.6TiO3 (BST) thin films were prepared by spin-coating technique and deposited on either Pt/TiO2/SiO2/Si (Pt/Si) substrate or silicon buffered by a lanthanum nickel oxide buffer layer (LNO/Si). X-ray diffraction and scanning electron microscopy showed that the BST films were crack free, compact and crystallized with a single perovskite structure. The effects of bottom electrodes on dielectric properties and energy storage performance of BST films were investigated. The results shows that the dielectric constant of BST/Pt film is a little higher than that of BST/LNO film, and the dielectric loss at 1 kHz of both films is very low, <;50/00. A butterfly loops with good dielectric tunability was observed in the capacitance-voltage (C-V) curve of BST/LNO film. The DC leakage current densities at 100kV/cm are ~9.3×10-9A/cm2 and ~1.0×10-8A/cm2 for BST/LNO and BST/Pt films, respectively. The P-E loops and energy storage performance of both films are similar. It was indicated that BST/LNO thin film can be applied as a cost-effective and environment-friendly capacitor for high-power energy storage.