Plasma-Enhanced Atomic Layer-Deposited Ti,Si-Doped ZrO₂ Antiferroelectric Films for Energy Storage Capacitors

Zr-based antiferroelectric (AFE) materials with a fluorite structure are promising candidates for replacing conventional dielectric materials in energy storage devices. However, single ZrO 2 exhibits an unsatisfactory energy storage performance. In this work, AFE Ti-doped ZrO 2 (ZTO) and Ti,Si-doped ZrO 2 (ZTSO) dielectrics are prepared using the plasma-enhanced atomic layer deposition (PEALD) technique. By adjusting the Ti and Si doping content in the dielectric, a significant improvement in the energy storage performance of the ZrO 2 -based AFE dielectric capacitor is achieved. For the ZTSO capacitor with Ti/Zr = 1/12 and Si/(Si + Zr + Ti) = 1/27, the optimal energy storage performance with energy storage density (ESD, 68.59 J/cm 3 ) and energy storage efficiency (ESE, 67.63%) is obtained. Compared with the Si-undoped capacitor, the ESD and ESE are enhanced by 14.49 and 88.89%, respectively. Finally, a three-dimensional (3D) ZTSO dielectric capacitor based on an AAO template with an aspect ratio of 100:1 demonstrates an ESD of up to 3123.53 J/cm 3 and an ESE of 66.19%. Meanwhile, the 3D dielectric capacitor reveals an excellent electric field cycling endurance of up to 10 8 cycles and superior temperature stability.