Eu3+ 이온이 첨가된 Ba3Mg(SiO4)2 형광체의 분광학 특성

Abstract

The red-emitting phosphors of Eu3+-doped Ba3Mg(SiO4)2 were prepared by solid state reaction method. The excitation and emission spectra and decay curves of Ba3Mg(SiO4)2:Eu3+ (0.5, 3, 7, 13, 16 mol %) are investigated by the optical and laser-excitation spectroscopy at room temperature. The thermogravimetre (TG) and differential thermal analysis (DTA) measurements were performed. The structural characteristic was investigated 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- are observed in the UV region. The excitation into the CT state causes the strong red emission at 617 nm due to the 5D0 → 7F2 transition. The strongest excitation line corresponding to the 5D0 → 7F6 transition is observed at 396 nm. Emission spectrum measured under excitation at 290 nm (Eu3+- O2- CT band) and at 396 nm (7F0 → 5L6). The CT band shifts to longer wavelength with increasing Eu3+-concentration. The structural distortion on the Eu3+ ions is responsible for the red shift of CT band. The emission intensity increases with increasing Eu3+-concentration up to 13 mol% and then luminescence quenching occurs over 16 mol% of Eu3+-concentration.