Optical properties and the band-gap variation in diverse Zn1-xSnxO nanostructures

Abstract

In this work, Zn1-xSnxO nanostructures with diverse morphological characters were prepared by hydrothermal technique. The morphology, structure, crystallization and the chemical states of the samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization of UV–Vis spectra indicates that the optical transmittance of Zn1-xSnxO nanostructure is above 90% in the visible range. The optical absorption edge of the samples was determined according to the Tauc relationship, and a remarkable bule shift of the band-gap appeared for the Zn1-xSnxO nanomaterials. The fluorescence spectra were measured by using photoluminescence (PL) spectrometer. The pure ZnO nanostructure exhibits a strong yellow emission and a weak near-ultraviolet emission. The effect of CTAB is mainly on the photoluminescence intensity rather than the peak position. However, the introduction of stannum has an interesting effect on the PL of ZnO. The Zn1-xSnxO nanostructure exhibits a remarkable near-band-edge (NBE) emission with two peaks. The dependence of NBE emission spectra on excitation power was analyzed. Two radiative recombination channels of the NBE emission have been discussed in detail.