Ultra-high energy storage density of transparent capacitors based on linear dielectric ZrO2 thin films with the thickness scaled up to hundreds nanometers
Yanbin Wang, Yong Wang, Huizhong Zeng, Xianhua Wei
Abstract
In this work, a high energy storage density in transparent capacitors, based on linear dielectric ZrO2 thin films, with thickness scaled up to hundreds of nanometers, is reported. Linear dielectric ZrO2 films with a thickness of several hundred nanometers are grown on Sn-doped In2O3 (ITO) electrode layers grown on transparent glass substrates at room temperature. The fabricated ITO/ZrO2/ITO capacitors show excellent dielectric energy storage performance, including a large dielectric constant, low loss and leakage current, and large breakdown strength. Consequently, these capacitors present high energy density and efficiency, as well as robust device endurance. In particular, ultra-high recoverable energy storage density (Wrec ∼ 75.4 J/cm3) and efficiency (η ∼ 88%) are achieved simultaneously in ZrO2 film-based (470 nm thick) capacitors, rivaling those of other lead-free ferroelectric-like and other linear dielectric film capacitors. Moreover, the capacitors show good transparency in the visible range, indicating the potential energy-storage applications in transparent electronics.