Influence of transition metal doping (X = Co, Fe) on structural, optical properties of Ferroelectric Bi3.25La0.75X1Ti2O12

Abstract

Studies of the photoelectric properties of complex oxides have recently focused on materials with a narrow band gap because the wide band gap of complex oxides is one of the major obstacles limiting their use in photovoltaic cells. To tune the band gap of complex oxides, this study examined the effects of cobalt and iron doping on lanthanum-modified Bi4Ti3O12-based oxides (BLT) synthesized using a solid reaction method. The structural, optical and electrical properties of the synthesized powers were examined by x-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy. Doping with both atoms affected the tunability of the band gap dramatically without breaking symmetry. On the other hand, the transition region in the band gap from the iron-doped sample was much sharper than that from the cobalt-doped sample. Control of the band gap chemical doping can be applied to other complex oxides materials and provides a new tool for manipulating oxide optoelectronics.