掺杂铽(Ⅲ)离子的邻苯二甲酸锶发光材料的晶体结构和发光机理

合成了掺杂三价铽离子的邻苯二甲酸锶发光材料。测定了材料的热稳定性、晶体结构及紫外吸收光谱、激发光谱和发射光谱。研究了晶体中邻苯二甲酸根单线态Sл、л1*、Sn、л1*跃迁吸收和由三线态Tл、л1*、Tn、л1*到铽(Ⅲ)离子5D4能级的能量传递机理。

CRYSTAL STRUCTURE AND LUMINESCENCE MECHANISM OF Tb3+-DOPED STRONTIUM PHTHALATE PHOSPHOR

The SrC8H4O4:Tb phosphor was prepared by the solution reaction method, and its thermal stability was examined.The powder X-ray diffraction and electron diffraction patterns were obtained.The SrC8H4O4:Tb crystal is a monoclinic, space group P21/n.Its lattice parameters were calculated to be α=1.4192, b=0.8018, c=1.3223nm,β=100.25 deg.The UV absorption, emission and excitationspectra were investigated.The energy transfer mechanism from C8H4O4 radical to Tb3+ ion was discussed.Underultraviolet excitation, the C8H4O4 radical is raised to singlet Sл,л1* and Sn, л1* excita tion states, it then decays from the tow states through intersystem crossing to triplet states Tл, л1* and T n, л1*, respectively.The Tл, л1* state in the energy corresponds to 5D4 enerty level of Tb3+ ion, so that the excitation enrtgy is very easily transferred to Tb3+ion to result in very strong 5D4-7F, emission.The T n, л1* state can transfer the energy to Tb+3ion, can also directly return to ground state by emitting blue fluorescence.