Band gap measurement of SrFeO3−δ by ultraviolet photoelectron spectroscopy and photovoltage method
Tan, Ooi Kiang
Date of Issue2012
School of Electrical and Electronic Engineering
Singapore Institute of Manufacturing Technology
There are very important characteristics of partial substitution of the cations at both A and B sites in ABO3 perovskite structure. In this report, SrFeO(3−δ) (SFO) photocatalyst powder was synthesized by a high temperature solid state reaction method. The morphology and crystalline structure of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM). The XRD, TEM and SAED patterns indicated that a single cubic perovskite phase of SrFeO(3−δ) (SFO) oxide has been successfully synthesized. The surface composition of the SrFeO(3−δ) sample was characterized by X-ray photoelectron spectroscopy (XPS). The XPS results showed that the iron existing in the SrFeO(3−δ) perovskite structure is composed of a mixture of Fe3+ and Fe4+. Due to the high absorbance of the SrFeO(3−δ) powder, the Kubelka–Munk model and UV–visible measurement were not applicable. Therefore, in order to study the band positions further, the valence band edges for electronic band gaps were obtained for SrFeO(3−δ) by ultraviolet photoelectron spectroscopy (UPS) while the conduction band position was obtained by photovoltage method.
DRNTU::Engineering::Electrical and electronic engineering
© 2012 The Royal Society of Chemistry.