Shape tunable synthesis of Eu- and Sm-doped ZnO microstructures: a morphological evaluation

Facile and low-cost aqueous chemical bath deposition route has been demonstrated to fabricate Eu- and Sm-doped ZnO microstructures. The effect of Eu and Sm ions on the morphology of the ZnO was investigated. The synthesized doped ZnO microstructures were systematically characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman and Fourier transform infrared spectra. FESEM images depicted the formation of Eu-doped ZnO microsphere and Sm-doped ZnO microplates. XRD spectra showed single crystalline nature of the undoped ZnO microdisks, whereas Eu- and Sm-doped ZnO exhibited the polycrystalline nature. The presence of Eu and Sm ions in the ZnO matrix was confirmed by XPS. This means that all the Eu ions substituted Zn2+ as Eu2+ into the ZnO matrix, whereas most of Sm ions were being in the trivalent state. This was probably due to the segregation of Sm2O3 species on the surface of ZnO microstructures.