Transition Metal Ions Doped Novel Phosphor for Solid State White Lighting

Transition metal ions doped NaCaAlPO4F3 phosphors have been synthesized using a solid state reaction method. The prepared samples are characterized by powder XRD, SEM, optical absorption, EPR, PL and FT-IR techniques. The XRD studies confirm the crystal structure of prepared phosphor samples as monoclinic system. SEM images show nanoclusters. Optical absorption and EPR spectra of TM ions doped phosphor exhibited the characteristic absorption bands and resonance signals of TM ions. The site symmetry of Cr(III), Mn(II) and Fe(III) ions in host lattice is ascribed to octahedral and distorted octahedral site symmetries respectively whereas in the case of Cu(II) ions doped phosphor, the site symmetry is tetragonally distorted octahedral. The PL spectra of all the dopants exhibit various emission bands which correspond to different regions like UV, blue, green, orange, yellow and red regions by exciting phosphors in UV or blue regions and the corresponding CIE coordinates are in blue, blue-green, red and near white regions. FT-IR spectra of all the TM ions doped phosphors exhibited the fundamental vibrations of PO4, P-O-H, F-P-F and water molecules.