Synthesis and optical properties of Eu-doped ZnO nanosheets by hydrothermal method

Eu-doped ZnO nanosheets with irregular porous microstructure were successfully prepared by a simple hydrothermal method. The microstructures, morphologies and optical properties of the as-prepared nanosheets were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL) and Raman spectroscopy. XRD and XPS results indicated that trivalent europium ions were successfully doped into the crystal lattice of ZnO matrix. Nanosheets with irregular porous can be seen from the TEM images. PL spectroscopy indicated that the peaks located at 580, 587 and 614 nm were attributed to the 4f–4f intrashell transitions of 5D0→7F0, 5D0→7F1 and 5D0→7F2 of Eu3+ ions,respectively, and the intensity ratio of 5D0→7F2 to 5D0→7F1 indicated that Eu3+ ions were incorporated into wurtzite ZnO host by substitution on the Zn sublattice and located at a low-symmetry site (C3v) without inversion center.