Influence of vacancies on the optical and electronic properties of the rhombohedral In ₂ O ₃ oxide

Abstract

Abstract To study the vacancy mechanism of In 2 O 3 , we apply the first‐principles method to study the influence of vacancy on the structural stability, electronic and optical properties of the rhombohedral In 2 O 3 . Two vacancies: In‐vacancy (V ‐In ) and O‐vacancy (V ‐O ) are considered here. The calculated results show that the rhombohedral In 2 O 3 with In‐vacancy and O‐vacancy are thermodynamic and dynamical stabilities based on the vacancy formation energy and phonon dispersion. In particular, In‐vacancy has better thermodynamic stability in comparison to the O‐vacancy. Importantly, the rhombohedral In 2 O 3 exhibits ultraviolet properties. However, two vacancies lead to the peak migration from the ultraviolet region to the visible light region. Furthermore, it is found that the calculated band gap of In 2 O 3 with In‐vacancy is 1.07 eV, which is wider than the parent In 2 O 3 (0.841 eV). Naturally, the wide band gap of In‐vacancy is that the removed In atom aggravates the difficulty of the electronic interaction between the conduction band and the valence band near the Fermi level. On the contrary, O‐vacancy shows metallic behavior because O‐vacancy (V ‐O ) enhances the electronic interaction near the Fermi level.