La2-xEux(WO4)3 고용체의 합성과 형광 특성

Abstract

Abstract

The red-emitting phosphors of Eu3+-doped La2(WO4)3 were prepared by solid state reaction method. The excitation and emission spectra of La2(WO4)3:Eu3+ (0, 0.01, 0.1, 1, 5, 10, 15, 30, 50, 100 mol %) are investigated by the laser-excitation spectroscopy at room temperature. The crystallinity of the samples were characterized by X-ray powder diffraction analysis. No obvious impurity phase was observed. The strong excitation bands due to the ligand to metal ion charge transfer (CT) transition of Eu3+ - O2- CT band are observed in the UV region for Eu3+ doped La2(WO4)3 phosphors. The excitation into the CT state causes the strong red emission at 618 nm due to the 5D0 → 7F2 transition. The strongest excitation line due to the 7F0 → 5L6 transition is observed at 397 nm. The emission spectra were obtained by excitation at 284 nm (Eu3+- O2- CT band) and at 397 nm (7F0 → 5L6). The emission intensity increases with increasing Eu3+-concentration up to 50 mol% and then luminescence quenching occurs over 70 mol% of Eu3+-concentration.