The lead-free Ba_0.53Sr_0.47TiO₃ (BST) thin films buffered with La_0.67Sr_0.33MnO₃ (LSMO) bottom electrode of different thicknesses were fabricated by pulsed laser deposition method on a (001) SrTiO₃ substrate. It was found that the roughness of electrode decreases and substrate stress relaxes gradually with the increase of LSMO thickness, which is beneficial for weakening local high electric field and achieving higher E_b. Therefore, the recoverable energy density (W_rec) of BST films can be greatly improved up to 67.3 %, that is, from 30.6 J/cm³ for the LSMO thickness of 30 nm up to 51.2 J/cm³ for the LSMO thickness of 140 nm after optimizing the LSMO thickness. Furthermore, the thin film capacitor with a 140 nm LSMO bottom electrode shows an outstanding thermal stability from 20 °C to 160 °C and superior fatigue resistance after 10⁸ electrical cycles with only a slightly decrease of W_rec below 1.6 % and 3.7 %, respectively. Our work demonstrates that optimizing bottom electrodes thickness is a promising way for enhancing energy storage properties of thin-film capacitors.

通过脉冲激光沉积法在（001）SrTiO ₃衬底上制备了具有不同厚度的La _0.67 Sr _0.33 MnO ₃（LSMO）底部电极缓冲的无铅Ba _0.53 Sr _0.47 TiO ₃（BST）薄膜。研究发现，随着LSMO厚度的增加，电极的粗糙度减小，衬底应力逐渐减小，这有利于减弱局部高电场并获得更高的E _b。因此，可以将BST薄膜的可恢复能量密度（W _rec）从30.6 J / cm ³大大提高到67.3％。在优化LSMO厚度后，对于LSMO厚度为30 nm的LSMO厚度为51.2 J / cm ³，对于LSMO厚度为140 nm的厚度达到51.2 J / cm ³。此外，具有140 nm LSMO底部电极的薄膜电容器在20°C至160°C的温度下表现出出色的热稳定性，在10 ^8个电循环后表现出优异的抗疲劳性，W _rec仅略微下降至1.6％和3.7％以下，分别。我们的工作表明优化底部电极的厚度是增强薄膜电容器储能性能的一种有前途的方法。