(CeO2)1/(HfO2)2 ferroelectric superlattice with low polarization switching energy barrier

HfO 2 ferroelectric materials have received widespread attention due to their compatibility with complementary metal-oxide semiconductor (CMOS) processes. However, the orthorhombic phase of HfO 2 is thermodynamically metastable, and its high polarization switching energy barrier results in a high coercive field, which severely limits the practical application of HfO 2 as a functional ferroelectric material. Therefore, developing HfO 2 -based ferroelectric materials with excellent ferroelectric phase stability and low polarization switching barriers is crucial for their applications in ferroelectric devices. In this work, the (CeO[Formula: see text]/(HfO[Formula: see text] superlattices were designed, and their ferroelectric phase stabilities and polarization switching properties were studied using density functional theory-based first-principles calculations. The (CeO[Formula: see text]/(HfO[Formula: see text] superlattice is found to exhibit good ferroelectric phase stability with out-of-plane oriented polarization. Its polarization switching energy barrier is reduced to 0.083 eV/u.c., which leads to a more than 40% lower switching electric field, as compared with that of pure HfO 2 . The underlying reason for the energy barrier reduction is the tensile strain induced by the superlattice. Our results indicate that the superlattice strategy with (CeO[Formula: see text]/(HfO[Formula: see text] structure is an effective approach for achieving low-power ferroelectric devices.