Improved luminescence properties of Na2TiSiO5 phosphor by the Ge4+ doping in the crystal lattice

Abstract

Rare earth free white emitting Na2TiSi1-xGexO5 phosphors were synthesized by a conventional solid-state reaction method, and the photoluminescence properties were characterized. The phosphors obtained in the present study showed broad bluish-white emission with a peak at 485 nm due to the charge transfer transition between O2- and Ti4+ and the emission peak intensity was effectively enhanced by the Ge4+ doping in the Na2TiSiO5 crystal lattice. The emission peak intensity of Na2TiSi0.5Ge0.5O5 was 1.35 times higher than that of Na2TiSiO5 and the CIE chromaticity coordinate values for the phosphor were x = 0.29 and y = 0.38.