Effect of calcination temperature on the structural and optical properties of ZnO:Fe powders

ZnO:Fe powders have been prepared by sol-gel method with different calcination temperatures (650 °C, 750 °C, 850 °C and 950 °C). The crystal structures and optical properties were investigated by X-ray diffraction (XRD), Raman spectra and Photoluminescence (PL). The XRD results demonstrated that all of the samples were hexagonal wurtzite structure, and with the increase of calcination temperature, the diffraction peak of (0 0 2) slightly shifts to larger degree. Furthermore, the lattice vibrations have been investigated by Raman spectra, with the increase of calcination temperature, the representative peak E2high of ZnO shifts from 437.5 to 434 cm−1, corresponding to degradation of crystalline quality. Also, the dependence of PL spectra on calcination temperature has been investigated detailed.

► Fe doped ZnO powders with hexagonal structure prepared by sol-gel. ► With the increase of calcination temperature, the second phase ZnFe2O4 appeared. ► 650 and 750 °C are optimal temperatures to improve the crystal quality and optical property, which making the small strain in samples. ► With the increase of calcination temperature, the stress converts to strain in samples, and strain increased.