Robust energy storage density and negative capacitance in antiferroelectric heterostructures grown by atomic layer epitaxy

Energy storage devices with high energy storage density ( U ESD ), fast operating speed, and high output power are indispensable for modern energy needs. This study presents a wafer-scale epitaxial antiferroelectric ZrO 2 /TiN heterostructure with a state-of-the-art high U ESD of ∼118.6 J cm −3 . This significant U ESD originates from the predominant [110] antiferroelectric polar axis of ZrO 2 oriented out-of-plane, which is confirmed by macroscopic and microscopic analyses of the epitaxial relationships. The construction of a coincidence site lattice indicates the low lattice mismatch between ZrO 2 (110) and TiN(111). The stacking of ZrO 2 sublayers demonstrates the importance of precise epitaxy in controlling crystal orientation, minimizing leakage current, and improving antiferroelectric characteristics. Furthermore, the epitaxial growth of ZrO 2 enables a clear observation of inductive-like negative capacitance response, providing insights into antiferroelectric dynamics. The high U ESD highlights the significance of atomic layer epitaxy for high-quality antiferroelectric heterostructures, particularly in epitaxial growth methods and energy storage applications. A state-of-the-art high energy storage density was achieved in an epitaxial ZrO 2 /TiN capacitor with the characterization of inductive-like negative capacitance via atomic layer epitaxy at low growth temperature, large area, and high working pressure.