Ensuring reliable and safe operation of high-power electronic devices necessitates the development of high-quality dielectric nano-capacitors with high recoverable energy density (U_Rec) and efficiency (η) at low applied electric fields (E)/voltages. In this work, we demonstrate ultra-high U_Rec and η at low E <500 kV/cm in as-grown epitaxial relaxor ferroelectric (RFE) PMN-33PT films, rivaling those typically achieved in state-of-the-art RFE and antiferroelectric (AFE) materials. The high energy storage properties were achieved using a synergistic strategy involving large polarization, a giant built-in potential/imprint (five times higher than the coercive field), and AFE like behavior. The structural, chemical, and electrical investigations revealed that these achievements mainly arise from the effects of strain, dipole defects, and chemical composition. For instance, at low E, the capacitors exhibit under 160 kV/cm (i.e., 8V) and 400 kV/cm (i.e., 20V), respectively, an ultra- high ΔP (45 μC/cm² and 60 μC/cm²), U_E= U_Rec /E (21 J⸱MV/cm² and 17 J⸱MV/cm²), and U_F=U_Rec/(1–η) (20 J/cm³ and 47 J/cm³) with a robust charge-discharge fatigue endurance and outstanding frequency and thermal stability. Additionally, the designed films exhibit outstanding energy storage performance at higher E up to 2 MV/cm (ΔP ≈ 78 μC/cm², U_E≈ 17.3 J⸱MV/cm² and U_F≈ 288 J/cm³) due to their low leakage current density.

中文翻译：

---

通过协同效应，在低电场/低电压下，电介质薄膜电容器具有超高的储能密度和效率


确保大功率电子设备的可靠和安全运行需要开发在低外加电场 （E）/电压下具有高可恢复能量密度 （U_Rec） 和效率 （η） 的高质量介电纳米电容器。在这项工作中，我们展示了在生长的外延弛豫铁电 （RFE） PMN-33PT 薄膜中低 E <500 kV/cm 下的超高 U_Rec 和 η，可与最先进的 RFE 和反铁电 （AFE） 材料中通常实现的相媲美。高储能特性是使用涉及大极化、巨大的内置电位/印记（比矫顽力场高五倍）和类似 AFE 的行为的协同策略实现的。结构、化学和电气研究表明，这些成就主要来自应变、偶极子缺陷和化学成分的影响。例如，在低 E 下，电容器分别低于 160 kV/cm（即 8V）和 400 kV/cm（即 20V），超高 ΔP（45 μC/cm² 和 60 μC/cm²），U_E= U_Rec /E（21 J·MV/cm² 和 17 J·MV/cm²）和 U_F=U_Rec/（1–η）（20 J/cm³ 和 47 J/cm³） 具有强大的充放电疲劳耐久性以及出色的频率和热稳定性。此外，由于其低泄漏电流密度，所设计的薄膜在高达 2 MV/cm（ΔP ≈ 78 μC/cm²、U_E≈ 17.3 J⸱MV/cm² 和 U_F≈ 288 J/cm³）的较高电流下表现出出色的储能性能。