Polycrystalline Compound of Co²⁺-doped Zn₂SnO₄: Structural and Photoluminescent Properties

Abstract

In this work, Zn₂SnO₄:Co²⁺ (0.1%) was obtained through a solid-state reaction at high temperature using ZnO, SnO₂, and CoCO₃. The sample was investigated using X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and photoluminescence spectroscopy. Rietveld refinements of the X-ray diffraction data showed two crystalline phases, Zn₂SnO₄ and SnO₂, with proportions of 97.24% and 2.76%, respectively, while Zn and Sn atoms were observed by X-ray fluorescence. Scanning electron microscopy images showed the polycrystalline nature of the material. Photoluminescence spectroscopy showed two emission bands in the red and near-infrared regions, with the broader and more intense band having a barycenter at 694 nm. The intensity of the emission changed with the excitation wavelength, whereas the barycenter remained unchanged. The intensity, shape, and position of the bands, as well as the calculated crystal field parameters, indicate the insertion of Co²⁺ ions in the tetrahedral sites of the Zn₂SnO₄ material.

Keywords
Photoluminescence; emission; Co²⁺; Zn₂SnO₄