Intense Photoluminescence Emission in Eu3+- and Dy3+- Doped Low-Band Gap Perovskite Titanate, Na0.5Gd0.5TiO3

摘要

abstract_textpNa0.5Gd0.5-xRExTiO3 (RE = Eu and Dy) phases with orthorhombic perovskite structure were synthesized by high temperature solid state reaction and the photoluminescence properties were investigated. The phase purity was confirmed by Rietveld refinement of the powder XRD patterns in Pnma space group. The band gap of the host was found to be 3.41eV from UV/Vis diffuse reflectance spectrum. In the Eu3+ doped phases, the (D0F2)-D-5-F-7 electric dipole (ED) transition is predominant in the emission spectrum of Eu3+, under 397nm excitation, and is in agreement with the non-centrosymmetric C-s point group of the EuO8 polyhedron. The critical concentration of the Eu3+ was found to be x = 0.075 above which, concentration quenching occurs. Dy3+ doping resulted in intense white light emission under 389 nm excitation./p/abstract_text