ZnO micro/nanostructures with various morphologies were grown via hydrothermal etching of Zn foil.Controlling the reaction temperature and time,rod-like,pencil-like,tube-like and flowerlike ZnO micro/nanostructures could be prepared directly on the Zn foil surface at temperatures 100-180℃ with excellent reproducibility.X-ray diffraction patterns indicated that these ZnO micro/nanostructures were hexagonal.Possible mechanisms for the variation of morphology are discussed.Moreover,photoluminescence spectra of the as-grown samples revealed that all of them consist of UV emission band at around 392 nm.
Using different-solution-concentration precursors with citric acid as chelating agent and polyvinyl alcohol as dispersing media, Dy3＋ activated LaVO4 films were deposited on indium tin oxide （ITO） substrates. The scanning electronic microscope （SEM） showed that the compact and crack-free LaVO4：Dy3＋ film could be obtained at a suitable solution concentration. The deposited films could absorb the ultraviolet light below 400 nm and were transparent in the visible and infrared region as evidenced by the transmission spectra, and the photolumines- cence spectra exhibited the characteristic emissions of Dy3＋ peaking at 484 （blue） and 576 （yellow） nm due to the transitions of 4F9/2→6Hls/2 and 4F9/2→6H13/2, respectively. The potential application of LaVOa：Dy3＋ film in the dye-sensitized solar cell （DSSC） was also discussed.
Photoluminescence properties of Sr 2.5 Dy 1/3-x Eu x V 2 O 8（x=0,0.06,0.12,0.18,0.24,0.33） were investigated.The excitation spectra included a broad band in the short wavelength region and several sharp lines in the longer wavelength region,and the spectral origin were discussed.The emission spectra were measured in two different exciting ways,i.e.,exciting the VO 4 group at 270 nm and the Eu 3＋ ion at 398 nm,respectively,and the energy transferring process was reasonably suggested.Furthermore,multi-color emission could be achieved in Sr 2.5 Dy 1/3-x Eu x V 2 O 8,indicating that the studied samples had potential applications in the white light emitting diodes.Further investigation showed that reducing the concentration of Eu 3＋ and Dy 3＋ and introducing Bi 3＋ as a sensitizer ion greatly enhanced the emission intensity.
