Characterization and luminescence properties of Sr3Gd(PO4)3: Sm3+ orange-red phosphor

Reddish-orange emitting phosphors, Sr(3)Gdd(PO4)(3): Sm3+, were successfully synthesized by a conventional solid-state reaction. The crystal structure of the phosphors was characterized by x-ray diffraction. The excitation spectra and emission spectra were utilized to characterize the luminescence properties of the as-prepared phosphors. The results show that the phosphor consisted of some sharp emission peaks of Sm3+ ions centered at 564, 600, 647, and 707 nm, respectively. The critical distance of Sr3Gd0.93(PO4)(3): 0.07Sm(3+) was calculated to be 19.18 angstrom and the lifetime value of the sample was 1.63 ms. The band gap of Sr(3)Gdd(PO4)(3) was estimated to be about 2.74 eV from the diffuse reflection spectrum. The optimum doping concentration is 7 mol. % and the quenching occurs via dipole-dipole interaction according to Dexter's theory. The Commission Internationale de L'Eclairage value of Sr(3)Gdd(PO4)(3):Sm3+ phosphors presented that it has high color purity. These results indicated that the Sr(3)Gdd(PO4)(3): Sm3+ may be a promising reddish-orange emitting phosphor for cost-effective near ultraviolet white light-emitting diodes. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)