High-Throughput Electronic Structures and Ferroelectric Interfaces of HfO2 by GGA+U(d,p) Calculations

Abstract

The electronic structure, vacancy symmetry, defect levels, ferroelectric phases, and interface properties of HfO2 are studied using a GGA + U(d,p) approach, a simplified version of the ACBN0 method. Introducing an on-site Coulomb interaction to both Hf 5d orbitals and O 2p orbitals reproduces the experimental bandgap, gives band energies similar to those of hybrid functionals, gives the correct symmetry for the oxygen vacancy, and describes the Schottky barriers at the metallic contacts like TiN correctly. The energetics of phase energies and strain arising from different ferroelectric–electrode interfaces are tested. The GGA + U(d,p) approach is a useful tool to study various HfO2 configurations by rapid ab initio molecular dynamics calculations.