Lu2O3:Er3+荧光粉的Judd-Ofelt参数计算

三价稀土离子掺杂透明发光材料的f-f跃迁性质可以根据Judd-Ofelt理论进行研究。对于不透明的粉末材料, 由于不能测量其吸收光谱, 难以采用传统的Judd-Ofelt理论进行计算。针对非透明材料, 本研究提出了一种利用漫反射光谱计算稀土掺杂粉末材料Judd-Ofelt参数的方法：首先, 利用Kubelka-Munk方程将漫反射谱转换为强度为相对值的吸收光谱, 然后计算得到相对Judd-Ofelt参数, 再利用荧光衰减测量对相对Judd-Ofelt参数进行修正, 得到真实的Judd-Ofelt参数。将该方法用于计算固相反应合成的Lu₂O₃：Er³⁺样品的Judd-Ofelt参数, 并把利用吸收截面计算得到的Er³⁺的⁴I_13/2能级的辐射跃迁速率与利用Judd-Ofelt参数计算得到的结果进行了比较, 证明研究提出的计算Judd-Ofelt参数的方法是可行的。

Calculation of Judd-Ofelt Parameters for Lu2O3:Er3+ Phosphor

Optical transition properties of trivalent rare earth ions in transparent luminescent materials can be investigated via Judd-Ofelt analysis. The traditional Judd-Ofelt analysis can not be applied to nontransparent powders since its absorption spectra are unable to be measured. Therefore, in this study, a procedure for calculating the Judd-Ofelt parameters was proposed by using defuse-reflection spectrum. Firstly, the defuse-reflection spectrum was transformed into relative absorption spectrum based on Kubelka-Munk function, and then the relative Judd- Ofelt parameters were confirmed from the relative absorption spectrum, at last the actual Judd-Ofelt parameters were obtained by using fluorescence decay data for calibrating the relative values. The method proposed for Judd-Ofelt parameters’ calculation was applied to Lu₂O₃:Er³⁺ phosphor prepared by solid-state reaction, and the method was confirmed. The obtained Judd-Ofelt parameters were examined by comparing the radiative transition rates of ⁴I_13/2 derived from the absorption cross section with which obtained from usual route by using the Judd-Ofelt parameters. The present study demonstrated that the proposed Judd-Ofelt analysis route is reliable and practical.