Spontaneous polarization enhancement in ferroelectric Hf_(0.5)Zr_(0.5)O_2 using atomic oxygen defects engineering: An ab initio study

摘要

Oxygen defect impacts on ferroelectricity in Hf0.5Zr0.5O2 (HZO) are systematically studied on the basis of first-principles calculations. Importantly, the oxygen vacancy and Frenkel pair could enhance the spontaneous polarization (P-s) by an average of 14.5%, while O-i could largely reduce P-s of HZO by 44.8% on the contrary. The altered P-s and, accordingly, the remanent polarization (P-r) agree well with the experimental results of polarization variability. Oxygen vacancy induced P-r enlargement is revealed to be the underlying mechanism responsible for the wake-up effect. Our results provide a guideline to boost the ferroelectricity via defect engineering in ferroelectric HZO. Published under license by AIP Publishing.