Optical properties of pure and transition metal-doped indium oxide

摘要

The band structure, the dielectric function, the reflectivity, therefractive index and the oscillator strength sum rule were cal-culated for pure In_2O_3, and alloyed In_(1.5)T_(0.5)O_3 (where T repre-sents 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 ap-proximation (LDA + U). Calculations of the optical spectrawere performed for the energy range 0-30 eV. The calcu-lated results indicate that the upper valance bands of In_2O_3 show a small dispersion and the value of the band gap in-creases for Sc and Y dopants and decreases for Ac and Ladopants. The calculations indicate that there are two bandgaps for In_2O_3. The first shows a strong optical absorption, asa direct band gap occurs from a 0.81 eV energy level belowthe top of valence band. The second shows a much weakerabsorption from the top of the valence band to the bottomof the conduction band. The refractive index for In_2O_3is1.69 nm at 800 nm, near the visible region.