Optical properties of pure and transition metal‐doped indium oxide

Abstract

The band structure, the dielectric function, the reflectivity, the refractive index and the oscillator strength sum rule were calculated for pure In2O3 and alloyed In1.5T0.5O3 (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 In2O3 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 In2O3. 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 In2O3 is 1.69 nm at 800 nm, near the visible region. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Dopant and Defect Induced Electronic States at In2O3 Surfaces

“…A displacement of the onset of strong optical absorption from the fundamental gap was also found in the earlier calculations of Karazhanov et al [54], although these authors did not realise the significance of this result. More recently, similar results have been found by Aliabad et al [59] and Bechstedt and coworkers [55,60]. However, the latter group initially argued that the low energy onset in optical absorption was attributable to transitions from occupied conduction band states into higher conduction band states rather than weakly allowed transitions from the topmost valence band into the bottom of the conduction band [55].…”

Enhancement of Nonlinear Optical and Dielectric Properties of Cu2O Films Sandwiched with Indium Slabs

“…The peak observed at 2.35 eV is close to that observed at 2.304 eV, which originates from the transitions from to of the conduction band, which is also known as the limit of the “green” excitonic series . The value of the energy being 2.35 eV, which is also observed in the dielectric spectra of In 2 O 3 , was assigned to the fundamental energy bandgap of indium oxide . The peak at this energy value is believed to relate to the interband transition from the valence to the conduction band states at the Γ‐point of In 2 O 3 …”

“…[15,19] The value of the energy being 2.35 eV, which is also observed in the dielectric spectra of In 2 O 3 , was assigned to the fundamental energy bandgap of indium oxide. [20] The peak at this energy value is believed to relate to the interband transition from the valence to the conduction band states at the Γ-point of In 2 O 3 . [19] As shown in Figure 4b, remarkable changes in the behavior of the imaginary part of the dielectric spectra are observed upon indium participation.…”

“…In light of the discussion in the preceding paragraph, it is possible to think that this peak results from the fundamental transitions in In 2 O 3 . [20] In addition, the imaginary part of the dielectric spectra can indicate information about the angular frequency (w) dependent optical conduction in the films. Employing the relation [13,18] σ ¼ ε im w=ð4πÞ, we attempted to obtain the optical conductivity parameters with the help of Drude-Lorentz models for optical conduction.…”

First-principle studies of the ternary palladates CaPd3O4 and SrPd3O4

“…To investigate various aspects of the materials, electron energy loss spectroscopy (EELS) is an essential tool [41]. It gives knowledge regarding elastically scattered and nonscattered electrons as well as information about the number and type of atoms being struck by the beam [42,43]…”