Synthesis, characterization and photoluminescence properties of CaSiO(3): Eu(3+) red phosphor

CaSiO(3):Eu(3+) (1-5 mol%) red emitting phosphors have been synthesized by a low-temperature solution combustion method. The phosphors have been well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and optical spectroscopy. PXRD patterns reveal monoclinic CaSiO(3) phase can be obtained at 900 degrees C. The SEM micrographs show the crystallites with irregular shape, mostly angular. Upon 254 nm excitation, the phosphor show characteristic fluorescence (5)D(0) -> (7)F(J) (J = 0, 1, 2, 3, 4) of the Eu(3+) ions. The electronic transition located at 614 nm corresponding to (5)D(0) -> (7)F(2) of Eu(3+) ions, which is stronger than the magnetic dipole transition located at 593 nm corresponding to (5)D(0) -> (7)F(1) of Eu(3+) ions. Different pathways involved in emission process have been studied. Concentration quenching has been observed for Eu(3+) concentration >4 mol%. UV-visible absorption shows an intense band at 240 nm in undoped and 270 nm in Eu(3+) doped CaSiO(3) which is attributed to oxygen to silicon (O-Si) ligand-to-metal charge-transfer (LMCT) band in the SiO(3)(2-) group. The optical energy band gap is widened with increase of Eu(3+) ion dopant. (C) 2010 Elsevier B.V. All rights reserved