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Eu 3+ -activated novel potassium gadolinium double vanadates K 3 Gd(VO 4 ) 2 phosphors have been synthesized via solid-state reaction. The crystal phase, surface morphology and photoluminescence properties of the phosphor were investigated. X-ray diffraction results demonstrate that K 3 Gd 1− x Eu x (VO 4 ) 2 has the monoclinic structure with the space group of p21/m(11). The emission spectra suggest that K 3 Gd 1− x Eu x (VO 4 ) 2 phosphors present an intense charge transfer band at 314 nm and a strong red emission of Eu 3+ ( 5 D 0 → 7 F 2 transition) at 617 nm. The optimum doping concentration of Eu 3+ ions in K 3 Gd 1− x Eu x (VO 4 ) 2 phosphors is around 50 mol% and the major mechanism for concentration quenching is the exchange interaction. The emitting light color of the phosphors can be tunable by varying excitation wavelength and a warm white light is achieved by the excitation at 337 nm. The luminescence properties suggest that the present phosphors may have potential applications as red and white emitting materials for w-LEDs in solid state lighting. [ABSTRACT FROM AUTHOR]