Solution combustion synthesis and luminescence dynamics of CaTiO3: Eu3+, Y3+ nanophosphors

Abstract

Perovskite titanate nanophosphors, Ca1-x-yYxTiO3:yEu3+ have been synthesized through solution combustion synthesis using metal-citrate complexation method. The optimum substitution of Y3+ ions in Ca0·93TiO3:0.07Eu3+ phosphor enhances the intensity of luminescence 10 times along with the realization of the color purity of 91% and the luminescence life time value to 1.3 ms. X-ray Photoelectron Spectroscopy studies confirm the 3+ oxidation state of yttrium and europium ions and the occupancy of these ions at Ca2+ sites. The sole presence of Raman modes representing the orthorhombic structure and the TEM analysis reveal the high degree of crystallinity of phosphors. The substitution of rare earth ions causes the distortion of local crystal structure symmetry by the tilting of TiO6 octahedra and this results in the shift of Raman modes of CaTiO3. The single exponential nature of luminescence decay curves suggests the occupancy of substituent ions at the Ca2+ sites. Judd- Ofelt analysis gives the quantum efficiency as 81.6% for the phosphor with optimum dopant concentration.