Er掺杂PbF2晶体的局域团簇结构与光谱性能研究OA北大核心CSTPCD

In this paper,a series of Er∶PbF2 crystals were successfully grown by Bridgman method.The first-principles calculation based on the density functional theory was applied to investigate the clustering effect of Er3+in PbF2 crystals in details.The relationship between the up-conversion(UC)luminescence properties(luminescence intensity,color variation)and the cluster structure in Er∶PbF2 crystals was obtained for the first time.It is found that as Er3+concentration increases,the clusters evolve from monomers to higher-order configurations,with the distance between Er3+ions decreasing and then increasing,resulting in the intensity of the red emission in the UC fluorescence first increasing and then decreasing,and the red-green luminescence ratio also decreases after the Er3+concentration is higher than 6.5％(mole fraction),indicating that the luminescence color can be adjusted from red to yellow-green.This study proves that the structural evolution of rare-earth ion clusters could regulate the spectroscopic properties of Er∶PbF2,which provides a novel method for the design of multi-color luminescent materials.