Eu3+ 이온이 첨가된 Na4Mg(PO4)2 형광체의 합성과 형광 특성

Abstract

The red-emitting phosphors of Eu3+-doped Na4Mg(PO4)2 were prepared by solid state reaction method. The excitation and emission properties of Eu3+ in Na4Mg(PO4)2 (0.01, 0.1, 1, 5 mol %) are investigated by optical and laser-excitation spectroscopy at room temperature. The crystal structure was characterized by X-ray powder diffraction analysis. No obvious impurity phase was observed. The excitation bands due to the ligand to metal ion charge transfer (CT) transition for Eu3+ doped Na4Mg(PO4)2 phosphors are observed in the wavelength region 200-350 nm. The CT band shifts to longer wavelength with increasing Eu3+-concentration. The strongest excitation line due to the 7F0 → 5L6 transition is observed at 396 nm. The excitation into the CT state causes the strong red emission at 619 nm due to the 5D0 → 7F2 transition. By increasing Eu3+-concentration the excitation and emission intensities increase linearly up to 5 mol %. The results are discussed in relation with energy transfer and cross relaxation in Eu3+ ions and crystals structure of Na4Mg(PO4)2 lattice.