[Preparation and photoluminescence investigation of europium-doped zinc oxide nanocrystalline].

Europium-doped zinc oxide nanocrystalline was successfully prepared by sol-gel process. Photoluminescence spectrum (PL), Photoluminescence excitation spectrum(PLE), and X-ray diffraction pattern(XRD) of nanocrystalline ZnO : Eu3+ with excitation wavelength 395 nm were measured at room temperature. The XRD pattern indicates that nanocrystalline ZnO : Eu3+ has a hexagonal wurtzite structure and is polycrystalline. The mean grain size of nanocrystalline ZnO : Eu3+ was calculated by Debye-Scherrer formula. The luminescence process of Eu(3+) -doped zinc oxide nanocrystalline was investigate using PL and PLE. Emission of 5D0 --> 7F1 (595 nm), 5D0 --> 7F3 (653 nm), 5D0 --> 7F2 (611 nm) of Eu3+ ions, and a weak and wide visible band of ZnO were observed. Also, the photoluminescence of nanocrystalline ZnO : Eu3+ exhibits a blue-shift. An energy transfer from excited states of ZnO hosts to doped Eu3+ ions centers was disclosed by the fact that that photoluminescence intensity maximum of nanocrystalline ZnO : Eu3+ changs with the doping concentration of Eu3+.

[Preparation and photoluminescence investigation of erbium-doped zinc oxide nanocrystalline].

Er3+ -doped zinc oxide nanocrystalline powders were successfully prepared by chemical precipitation method. Photoluminescence spectrum (PL), photoluminescence spectrum excitation(PLE) and X-ray diffraction pattern (XRD) of the nanocrystalline ZnO:Er3+ with excitation wavelength 365 nm were measured at room temperature. XRD pattern indicates nanocrystalline ZnO:Er3+ has a hexagonal wurtzite structure and polycrystallining. The mean grain size of nanocrystalline ZnO:Er3+ was calculated with Debye-Scherrer formula. The luminescence process of Er3+ -doped zinc oxide nanocrystalline was investigated by using PL and PLE. Emissions of S(3/2)(550 nm), 2H(11/2))(521 nm) and 4F(5/2)(456 nm) of Er3+ ions were observed in wide visible band of ZnO. By analyzing the spectrum the effect of Er3+ -doping on the luminescence of ZnO was studied. An energy transfer from excited states of ZnO hosts to doping Er3+ ions centers was disclosed by the fact that photoluminescence intensity maximum of nanocrystalline ZnO = Er3+ changed with the doping concentration of Er3+.