Synthesis and photoluminescence of multicolor tunable K3Gd(VO4)2:Eu3+ phosphors

Eu3+-activated novel potassium gadolinium double vanadates K3Gd(VO4)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 K3Gd1−xEux(VO4)2 has the monoclinic structure with the space group of p21/m(11). The emission spectra suggest that K3Gd1−xEux(VO4)2 phosphors present an intense charge transfer band at 314 nm and a strong red emission of Eu3+ (5D0 → 7F2 transition) at 617 nm. The optimum doping concentration of Eu3+ ions in K3Gd1−xEux(VO4)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.