Ca替代Sr对Sr_2Si_5N_8:Eu^(2+)荧光粉结构、光谱及热猝灭性能的影响

Effect of Ca Substituting Sr on the Structure,Spectra and ThermalQuenching Performance of Sr_2Si_5N_8:Eu^(2+)

采用高温固相法制备了Sr_(2-x)Ca_xSi_5N_8:Eu^(2+)荧光粉,研究了Ca替代Sr对Sr_2Si_5N_8:Eu^(2+)晶体结构及发光性能的影响规律。结果表明Ca_2Si_5N_8和Sr_2Si_5N_8结构之间只能形成有限固溶体,随着Ca掺杂含量的改变,固溶体结构逐渐从正交晶系过渡到单斜晶系;进而导致其发射光谱呈现先红移后蓝移现象,且荧光粉的热猝灭性能逐渐呈降低趋势,但衰减幅度取决于Ca掺杂含量,当x>1.2时荧光粉的热猝灭性能衰减幅度增大,相应的衰减机制主要采用位移坐标模型来解释。

In this paper, Sr 2- x Ca x Si 5N 8: Eu^2+ phosphors were prepared by high temperature solid phase method, and the effect of Ca substituting Sr on the crystal structure and luminescence properties of Sr 2Si 5N 8: Eu^2+ was studied. The results show that only a limited solid solution can be formed between the Ca 2Si 5N 8 and Sr 2Si 5N 8 structure. With the change of Ca doping content, the solid solution structure gradually transitions from the orthorhombic system to the monoclinic system, which leads to the emission spectrum first red-shift and then blue-shift. And the thermal quenching performance of the phosphor gradually decreases. The attenuation amplitude depends on the Ca doping content. When x >1.2, the thermal quenching performance of the phosphor decreases rapidly, and the corresponding attenuation mechanism is studied by the displacement coordinate model.