Tunable white light-emission of a CaW 1-x Mo x O 4:Tm 3+, Tb 3+, Eu 3+ phosphor prepared by a Pechini sol-gel method

A white light-emitting CaW 1-x Mo x O 4:Tm 3+, Tb 3+, Eu 3+ phosphor was prepared by a Pechini sol-gel method. The incorporation of Mo 6+ into the CaWO 4 host matrix can broaden its excitation range and promote tunability to its emission. When the CaW 1-x Mo x O 4 system is triply-doped with Tm 3+, Tb 3+, and Eu 3+ ions, energy transfer occurs from both WO 4 2- and MoO 4 2- groups to Tm 3+ and Tb 3+ ions. A significant red-shift in the excitation of Eu 3+ allows the resulting emission to be tunable between cool, natural, and warm white light by varying the excitation wavelength. The undoped and triply-doped CaW 1-x Mo x O 4 phosphors were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence excitation and emission spectra, and CIE chromaticity (x, y) coordinates. © 2012 Springer Science+Business Media, LLC.