Kamaei, SadeghGhini, MicheleGilani, AliGastaldi, CarlottaCollette, EloiIonescu, Adrian Mihai2024-02-202024-02-202024-02-202023-09-0110.1109/LED.2023.3296945https://infoscience.epfl.ch/handle/20.500.14299/204433WOS:001108431800048In this work, we investigate the fundamental effects contributing to energy storage enhancement in on-chip ferroelectric electrostatic supercapacitors with doped high-k dielectrics. By optimizing energy storage density and efficiency in nanometer-thin stacks of Si:HfO2 and Al2O3, we achieve energy storage density of 90 J/cm(3) with efficiencies up to 90%. We demonstrate for the first time that in such ferroelectric stacks, both negative capacitance and dipole switching contribute to energy density enhancement, with an enhancement of more than 30% when the negative capacitance regime is exploited. These findings lay the groundwork for the design and operation in the most appropriate regime of on-chip energy storage rechargeable devices based on ferroelectric stacks.TechnologyNegative CapacitanceFerroelectric MaterialsEnergy StorageNc Supercapacitorstext::journal::journal article::research article