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

Ba
0.4
Sr
0.6
TiO
3
(BST) thin films were prepared by spin-coating technique and deposited on either Pt/TiO
2
/SiO
2
/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, <5‰. 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
⁻⁹
A/cm
²
and ∼1.0×10
⁻⁸
A/cm
²
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.