탄소열환원법에 의한 Ba3P4O13:Tb3+ 형광체의 합성과 분광학 특성 연구

Abstract

Tb3+ doped Ba3P4O13 phosphors were synthesized by the solid state reaction method under the thermal-carbon reducing atmosphere (TCRA) and air conditions. The structural characteristic and phase formation were investigated by X-ray powder diffraction. The single phase of Ba3P4O13 lattice is confirmed and no obvious impurity is observed. The optical properties of Ba3P4O13:Tb3+ were investigated by using excitation and emission spectroscopy and time-resolved laser-excitation spectroscopy. The excitation band centered at 231 nm is attributed to the f–d transition of Tb3+ in the Ba3P4O13 lattice. The strong emission lines at 378 and 547 nm are attributed to the 5D3 → 7F6 transition and the 5D4 → 7F6 transition of Tb3+ in Ba3P4O13, respectively. The Ba3P4O13:Tb3+ phosphors synthesized under the TCRA condition exhibit stronger luminescence efficiency than those under the air condition in which the luminescence enhancement with TCRA is more prominent at higher Tb3+-concentration. The changes in relative emission intensity between the 5D3 → 7FJ transition and the 5D4 → 7FJ transition are observed with increasing Tb3+-concentration which are attributable to the cross relaxation between Tb3+ ions, especially at high Tb3+ concentration in Ba3P4O13.