The study investigates the enhanced polarization switching characteristics of HfO₂ ultrathin films through acceptor-donor co-doping. HfO₂-based ferroelectric materials are known for their CMOS compatibility and scalability, but their switching speed and polarization are not as advanced as those of perovskite ferroelectrics. Defects play a crucial role in stabilizing the metastable polar phase of HfO₂, but they also impede the switching process. The researchers propose a co-doping strategy using La³⁺ and Ta⁵⁺ to address this issue. The co-doped HfO₂ films exhibit significantly improved ferroelectric properties, including a 2Pf increase of 83% and a reduction in coercive fields compared to La³⁺-doped films. These films show robust macro-electrical characteristics even at a thickness of 3 nm, making them suitable for ultrathin devices. The co-doping strategy reduces the defect state, leading to a more uniform microstructure and a reduced switching barrier, resulting in faster switching dynamics. First-principles calculations further elucidate the mechanism behind the enhanced switching properties, confirming that co-doping inhibits oxygen vacancy generation and reduces the polarization switching barrier. This work provides a promising approach to improve the performance of HfO₂-based ferroelectric devices.The study investigates the enhanced polarization switching characteristics of HfO₂ ultrathin films through acceptor-donor co-doping. HfO₂-based ferroelectric materials are known for their CMOS compatibility and scalability, but their switching speed and polarization are not as advanced as those of perovskite ferroelectrics. Defects play a crucial role in stabilizing the metastable polar phase of HfO₂, but they also impede the switching process. The researchers propose a co-doping strategy using La³⁺ and Ta⁵⁺ to address this issue. The co-doped HfO₂ films exhibit significantly improved ferroelectric properties, including a 2Pf increase of 83% and a reduction in coercive fields compared to La³⁺-doped films. These films show robust macro-electrical characteristics even at a thickness of 3 nm, making them suitable for ultrathin devices. The co-doping strategy reduces the defect state, leading to a more uniform microstructure and a reduced switching barrier, resulting in faster switching dynamics. First-principles calculations further elucidate the mechanism behind the enhanced switching properties, confirming that co-doping inhibits oxygen vacancy generation and reduces the polarization switching barrier. This work provides a promising approach to improve the performance of HfO₂-based ferroelectric devices.