Spectroscopic properties of Dy3+doped ZnO for white luminescence applications.
Undoped and Dy3+(0.25, 0.5, 0.8 and 1.5at.%) doped ZnO were elaborated by solid-state reaction method. The ZnO:Dy3+samples were characterized using X-ray diffraction (XRD), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy and photoluminescence (PL). The XRD analysis confirms the wurtzite structure of ZnO. A slight shift to lower angles, of the (101) peak, is seen with Dy3+content, indicating the substitution of these ions into the ZnO lattice. Raman study indicates the good crystallinity of all ZnO:Dy3+samples and confirms the substitution of Zn2+by Dy3+. The band gap energy was found to increase then decrease with Dy content. The PL excitation spectra (PLE) of Dy3+showed six excitation bands with hypersensitive at 346nm (6H15/2→6P7/2). PL spectra show principally three emission bands relatives to4F9/2→6H15/2(476nm),4F9/2→6H13/2(567nm) and4F9/2→6H11/2(658nm) transitions. The concentration dependency of PL intensity indicates a quenching for Dy3+concentration above 0.5at.%. The PL lifetime of4F9/2metastable state was measured and discussed for all Dy content in ZnO. The temperature dependency of PL intensity is investigated for ZnO:Dy (0.5%) sample and the activation energy is determined. The CIE chromaticity color coordinate shows that ZnO:Dy3+can be useful for white luminescence applications.
Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, BP 95, Hammam-Lif 2050, Tunisia.
Guesmi
G
Amira
Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, BP 95, Hammam-Lif 2050, Tunisia.
Bouzidi
B
Chaker
Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, BP 95, Hammam-Lif 2050, Tunisia; Department of Physics, Sciences Faculty of Tunis, University of Tunis El Manar, Tunis 2092, Tunisia. Electronic address: habib.elhouichet@fst.rnu.tn.
Elhouichet
E
Habib
Energy transfer; Optical properties, Dy(3+) ions; White LED; ZnO