Synthesis, structure and luminescence properties of new blue-green-emitting garnet-type Ca3Zr2SiGa2O12: Ce3+ phosphor for near-UV pumped white-LEDs

A new blue-green-emitting phosphor Ca3Zr2SiGa2O12: Ce3+ has been synthesized by a conventional high temperature solid-state reaction method from the viewpoint of exploring new luminescent materials for white light-emitting diodes. The crystal structure of Ca3Zr2SiGa2O12 was investigated by the powder Xray diffraction refinement and verified to be garnet-type with the Ia3d space group and lattice constant a = b = c = 12.5730(7) angstrom. The luminescence properties, concentration quenching, fluorescence lifetime, thermal quenching, quantum efficiency, chromaticity coordinates and related mechanisms of the Ca3Zr2SiGa2O12: Ce3+ phosphor were investigated in detail. The optimized phosphor shows two main broad excitation bands with peaks at 330 nm and 400 nm, respectively, in the region of 300-450 nm, and exhibits intense blue-green emission with a peak wavelength at 478 nm under 400 nm excitation. The above results indicated that the phosphor can be effectively excited by near ultraviolet light and may have potential application as a near UV-convertible phosphor for white light-emitting diodes.