A novel white-emitting Ca2Ga2GeO7∶Dy3+ 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 4F9/2 to 6H1s/2,6H13/2 and 6H11/2 of Dy3+,respectively.By varying the doping concentration of Dy3+,tunable colors from blue-white to yellow-white were obtained in the phosphors.Besides,by codoping charge compensators (Li+,Na+,K+ and Ga3+) in Ca2Ga2GeO7∶Dy3+,the optimum CIE color coordinate and PL intensity were obtained in Ca2Ga2GeO7∶Dy3+,K+.Accordingly,the PL mechanism of Ca2Ga2GeO7∶Dy3+ was discussed briefly.