Optical properties of Eu3+ - doped Sr2TiO4 phosphor powder synthesised by solid-phase reaction method

Abstract

Fluorescent powder Sr2TiO4 doped with Eu3+ ions was synthesised by the solid-phase reaction method with a sintering temperature of 1200oC in the air with a 1-6% doping concentration. The resulting material has a perovskite structure of I4/mmm space group, and the Eu3+ ion doping concentration does not change the material’s structure. This characteristic space group of the material was also investigated through the Raman scattering spectrum with characteristic peaks at positions 145, 240, 448, and 699 cm-1 corresponding to vibrational modes with 2A1g + 2Egcharacteristic states of Sr2TiO4 material. The results showed that the material absorbs strongly in the ultraviolet and blue light regions with characteristic peaks of the Sr2TiO4 matrix and Eu3+ ions to emit strongly in the red light region with characteristic emission peaks of Eu3+ ions in the background network when moving from the excited state 5D0 to state 7Fj (j is a positive integer number). Fluorescence quenching was also observed at a doping concentration of 4% Eu3+ ions. The fabricated material is suitable for coating applications on nUV-LED LED chips.