LuPO_4晶体中F心和F^+心的光谱性质模拟计算

Optical Properties Simulating Calculation of the F or F^+ Center in LuPO_4 Crystal

基于密度泛函理论下的广义梯度近似结合平面波赝势方法计算得到LuPO_4晶体的缺陷形成能,对带电缺陷与其镜像之间周期性库伦作用进行修正,得到比较精确的不同带电态的氧空位缺陷形成能,并利用杂化泛函方法修正带隙和带边.考虑电子声子耦合作用结合缺陷形成能构建光谱.对比LuPO_4∶Nd的实验结果与计算结果,发现F心的吸收峰与Nd^(3+)的5d—4f发射峰重叠(位于189nm),表明LuPO_4∶Nd中光产额较低的原因与F心的存在有密切关系.

The defect formation energy of LuPO4 crystal is calculated by generalized gradient approximation combined with plane wave pseudo-potential based on density functional theory.The periodic arrangement of the defect introduces artifical interactions is corrected.The oxygen vacancy defect formation energy in different charged states is obtained accurately,and band gap is modified through Hybrid functional.The optical line shapes are described by the defect formation energy and electronphonon coupling.The comparison of LuPO4 ∶ Nd experimental and calculated results shows the absorption peak of F center are superimposed on Nd^（3＋） 5 d—4 femission（located at 189 nm）.It is inferred that F center is found to be responsible for the limited light yield in LuPO4∶Nd.