The presence of uncontrolled defects is a longstanding challenge for achieving high electric resistivity and high energy storage density in dielectric capacitors. In this study, opposite to conventional strategies to suppress defects, a new approach, i.e., constructing defects with deeper energy levels, is demonstrated to address the inferior resistivity of BiFeO₃-based dielectric films. Deep-level vacancy complexes with high charge carrier activation energies are realized via deliberate incorporation of oxygen vacancies and bismuth vacancies in low-oxygen-pressure deposited films. This method dramatically increases the resistivity by ∼4 orders of magnitude and the breakdown strength by ∼150%, leading to a ∼460% enhancement of energy density (from 14 to 79 J cm⁻³), as well as improved efficiency and performance reliability. This work reveals the significance of rational design and precise control of defects for high-performance dielectric energy storage. The deep-level vacancy complex approach is generalizable to wide ranges of dielectric systems and functional applications.

不受控制的缺陷的存在是在介电电容器中实现高电阻率和高能量存储密度的长期挑战。在这项研究中，与抑制缺陷的传统策略相反，展示了一种新方法，即构建具有更深能级的缺陷，以解决基于BiFeO ₃的介电膜的低电阻率问题。具有高电荷载流子活化能的深能级空位复合物是通过在低氧压力沉积膜中有意掺入氧空位和铋空位来实现的。这种方法使电阻率显着增加了约 4 个数量级，击穿强度增加了约 150%，导致能量密度提高了约 460%（从 14 到 79 J cm ^-3)，以及提高效率和性能可靠性。这项工作揭示了合理设计和精确控制缺陷对于高性能介电储能的重要性。深层次空位复合方法可推广到广泛的介电系统和功能应用。