First-principles calculations of electronic and optical properties of F, C-codoped cubic HfO2

• Strong 2p–2p/5d admixtures result in a half-metallic ferromagnetism behavior.
• Both 2p–2p and 2p–5d/2p–2p interactions contribute to long-range magnetic coupling.
• F and C codoping induces obvious increase of refractive index.
• F and C codoping induces new steep absorption peaks at lower energy region.

First-principles calculations based on DFT+U were performed on electronic and optical properties of F, C-codoped cubic HfO2. The calculations show that strong 2p–2p/5d admixtures result in half-metallic ferromagnetism behaviors of F, C-codoped cubic HfO2. Both the direct 2p–2p interaction and the indirect 2p–5d/2p–2p coupling interactions can be expected to contribute to the long-range magnetic coupling. Meanwhile, F and C codoping induces obvious increase of refractive index and new steep absorption peaks at lower energy region ∼2.8 eV, which can be used for photoabsorption applications.