The effect of stress on electronic structure and optical properties of CeO2

Abstract

The effect of stress on the electronic structure and optical properties of CeO2 is studied using the ultrasoft pseudopotential plane wave method based on density functional theory. The results show that the band gap decreases quasi-linearly with the negative stress increasing and increases quasi-linearly with the increase of positive stress. Combining with the density of states (DOS) analysis, the main reason for the change of the band gap is Ce 4f electrons are significantly affected by the stress. When the stress changes from −25 to 30 GPa, the DOS of Ce 4f is far away from the Fermi level and gradually decreases. The influence of stress on optical properties mainly shows two obvious features. The first feature is that the optical properties are gradually appeared as the stress changes from −25 to 30 GPa and the optical edges are moved to high energy direction, in the energy range of 0–3 eV. Another feature is that there is an obvious peak value under the stress of −25–0 GPa, but does not significantly change under the stress of 0–30 GPa, in the energy range of 3–6 eV. The results show that the negative stress enhances the electronic transition, which is beneficial to improve the utilization of light.