A single-phased white-emitting Ca2Ga2GeO7:Dy3+ phosphor with different charge compensation ions

Abstract A novel white-emitting Ca 2 Ga 2 GeO 7 :Dy 3+ phosphor was synthesized via a high-temperature solid-state reaction. The crystal phase was analyzed by X-ray diffraction (XRD), and the photoluminescence (PL) properties were studied by luminescence spectra and fluorescence decay curves. Under the excitation of 347 nm, the obtained phosphor exhibited strong emission in the blue region peaked at 478 nm, yellow at 574 nm and a weak red emission band at 665 nm, corresponding to the characteristic transitions of 4 F 9/2 to 6 H 15/2 , 6 H 13/2 and 6 H 11/2 of Dy 3+ , respectively. By varying the doping concentration of Dy 3+ , tunable colors from blue-white to yellow-white were obtained in the phosphors. Besides, by codoping charge compensators (Li + , Na + , K + and Ga 3+ ) in Ca 2 Ga 2 GeO 7 :Dy 3+ , the optimum CIE color coordinate and PL intensity were obtained in Ca 2 Ga 2 GeO 7 :Dy 3+ ,K + . Accordingly, the PL mechanism of Ca 2 Ga 2 GeO 7 :Dy 3+ was discussed briefly.