Scale-up and optimization of HfO2-ZrO2 solid solution thin films for the electrostatic supercapacitors

The crystallization in the as-deposited state and the resulting low-k monoclinic phase evolution were suppressed by changing the Zr content and the deposition temperature of the electrostatic supercapacitors based on the HfO2-ZrO2 solid solution. While the energy storage density of the Hf0.3Zr0.7O2 thin films deposited at 280 °C drastically decreased at the large thickness due to the monoclinic phase formation (upper panel), the Hf0.5Zr0.5O2 thin films deposited at 210 °C retained the large energy storage density even up to 40 nm (bottom panel), enabling the scaling-up pathway of the HfO2-ZrO2 solid solution.239