Optical properties of pure and transition metal‐doped indium oxide

Abstract

Abstract The band structure, the dielectric function, the reflectivity, the refractive index and the oscillator strength sum rule were calculated for pure In 2 O 3 and alloyed In 1.5 T 0.5 O 3 (where T represents Sc, Y, La and Ac) using density functional theory (DFT). The full potential linearized augmented plane wave (FP‐LAPW) method was used with the local density approximation (LDA + U ). Calculations of the optical spectra were performed for the energy range 0–30 eV. The calculated results indicate that the upper valance bands of In 2 O 3 show a small dispersion and the value of the band gap increases for Sc and Y dopants and decreases for Ac and La dopants. The calculations indicate that there are two band gaps for In 2 O 3 . The first shows a strong optical absorption, as a direct band gap occurs from a 0.81 eV energy level below the top of valence band. The second shows a much weaker absorption from the top of the valence band to the bottom of the conduction band. The refractive index for In 2 O 3 is 1.69 nm at 800 nm, near the visible region. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)