Influence of aliovalent cation substitutions on the optical properties of In2Cu2O5 system

Abstract

The influence of aliovalent cation substitutions in In2Cu2O5 system on the optical properties has been investigated through the powder X-ray diffraction coupled with Rietveld analysis, UV–vis–NIR spectroscopy, scanning electron microscope attached with energy dispersive spectrometer. The aliovalent cation substitution affected the optical absorption of the system distinctly as the counter cation substitution of Sc3+ influences the crystal field environment of Cu2+ ions more dominantly than that of the direct substitution of Zn2+ ions. Consequently this allowed the red shift of the absorption edge pronouncedly in the case of Sc3+ substituted samples than that in the Zn2+ substituted ones. The key factor responsible for achieving the larger red shift in Sc3+ substituted sample is due to increased anion polarizability. The assessments of crystal field and tetragonality parameters corroborate the variation of charge transfer energies for the aliovalent cation substitutions. The modified absorption properties translated in enhancing the green chromacity and reflectance of the In2Cu2O5 system even better than the commercially available chromium oxide green (Cr2O3).