First-principles generalized gradient approximation (GGA) +Ud+Up studies of electronic structures and optical properties in cubic HfO2

TL;DR

This study uses GGA+Ud+Up calculations to accurately determine the electronic structures and optical properties of cubic HfO2, aligning theoretical results with experimental data and revealing detailed optical features.

Contribution

It introduces a combined GGA+Ud+Up approach to better predict the band gap and optical properties of cubic HfO2, improving upon previous methods.

Findings

Band gap matches experimental value of 5.7 eV with GGA+Ud+Up

Dielectric function shows a shoulder structure below main absorption peak

GGA+Ud+Up approach effectively predicts electronic and optical properties

Abstract

The electronic structures and optical properties of cubic HfO2 are calculated by means of generalized gradient approximation (GGA) +U approach. Without on-site Coulomb interactions, the band gap of cubic HfO2 is 2.92eV, much lower than the experimental value (5.7eV). Introducing the Coulomb interactions of 5d orbitals on Hf atom (Ud) and of 2p orbitals on O atom (Up), we can reproduce the experimental value of the band gap. The calculated dielectric function of cubic HfO2 by the GGA+ Ud + Up approach predicts the presence of a shoulder structure below the main peak of the absorption spectrum. These indicate that the GGA +Ud +UP approach is a convenient and powerful method to calculate and predict the electronic structures and the optical properties of wide-gap optical materials.