Controlled synthesis, optical and electronic properties of Eu3+ doped yttrium oxysulfide (Y2O2S) nanostructures

Single crystalline Eu(3+) doped yttrium oxysulfide (Y(2)O(2)S) nanocrystals, nanosheets, nanobelts, nanotubes, nanorods and nanowires have been successfully prepared via precursors of Y(OH)(3) nanostructures in high yields and purities by a convenient hydrothermal method under mild conditions. Comprehensive structural, morphological and spectroscopical studies have been carried out on the nanometre scale. The as-prepared samples are characterized using X-ray photoelectron spectra (XPS), to investigate the elementary states on the surfaces. A significant shift (approximately 0.22-0.36 eV) in the optical spectra of the Y(2)O(2)S:Eu(3+) system corresponding to the fundamental absorption and charge transfer bands, respectively, with respect to the bulk counterpart. The zero and one-dimensional (1D) nanostructures are good candidates for investigating size-induced opto-electronic properties of functional oxysulfides. In order to identify the origin and nature of the electronic transitions observed in the visible region, the photo-induced impedance measurements have been extended to the zero and 1D nanostructures.