Fig. 2: Extra Hole doping modulation effects on phase stability and related electronic structures.
From: Extra hole threshold in HfO2 ferroelectric phase stabilization
Optimal extra hole doping concentrations for stabilizing the O-phase under varying concentrations of threefold-coordinated oxygen vacancy (VOⅢ) (a) and fourfold-coordinated oxygen vacancy (VOⅣ) (b). Density of states (DOS) of O-, M-phase (VO = 0.00%) under 0.2 h/f.u. (c) and 0.3 h/f.u. d Extra hole doping concentration. e Evolution of electrostatic energy (Es) in the HfO2 matrix under varying extra hole doping concentrations and with either no (0.00%) or 1.04% concentrations of oxygen vacancies at threefold-coordinated (VOⅢ) and fourfold-coordinated (VOⅣ) oxygen sublattices. The aforementioned results unambiguously demonstrate that additional hole doping effectively stabilizes ferroelectric phase of HfO₂, irrespective of the presence of oxygen vacancies.
