In2O3 doped with hydrogen: electronic structure and optical properties from the pseudopotential Self-Interaction Corrected Density Functional Theory and the Random Phase Approximation

摘要

We discuss the applicability of the pseudopotential-like self-interactioncorrection (pSIC) to the study of defect energetics and electronic structure ofIn2O3. Our results predict that substitutional (at oxygen sites) andinterstitial (at antibonding positions) hydrogen, as well as oxygen vacancieswith charges +1 and +2, are stable configurations of defects in cubic In2O3;the former form shallow levels (only as substitutional defects), whereas thelatter form deep levels. The band structure calculated with the pSIC shows anexcellent agreement with experimental data. In particular, the gap fordefect-free In2O3 is 2.85 eV, which compares fairly with the experimental range2.3-2.9 eV. The pSIC results also point to a change from indirect to directgaps depending on doping. In relation to the optical properties, obtainedwithin the random phase approximation, it is shown that they are mostlyaffected by the presence of oxygen vacancies.