Tunable white light-emission of a CaW1−x Mo x O4:Tm3+, Tb3+, Eu3+ phosphor prepared by a Pechini sol–gel method

Abstract

A white light-emitting CaW1−x Mo x O4:Tm3+, Tb3+, Eu3+ phosphor was prepared by a Pechini sol–gel method. The incorporation of Mo6+ into the CaWO4 host matrix can broaden its excitation range and promote tunability to its emission. When the CaW1−x Mo x O4 system is triply-doped with Tm3+, Tb3+, and Eu3+ ions, energy transfer occurs from both WO4 2− and MoO4 2− groups to Tm3+ and Tb3+ ions. A significant red-shift in the excitation of Eu3+ allows the resulting emission to be tunable between cool, natural, and warm white light by varying the excitation wavelength. The undoped and triply-doped CaW1−x Mo x O4 phosphors were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence excitation and emission spectra, and CIE chromaticity (x, y) coordinates.