Local Structure Analysis in Nitride and Oxynitride Phosphors

In rare-earth- or transition-metal-doped phosphors, the luminescence properties are strongly dependent on the crystal structure of the host material, in particular the local coordination structure at the luminescence centers. Therefore, in order to control the luminescence properties, it is important to determine factors such as the coordination number, interatomic distance, symmetry and coordinating anion species. Doping levels in phosphors are generally low and have little impact on the overall structure of the material. For this reason, a local structural analysis is required in the neighborhood of the luminescence centers. In this paper, such an analysis is shown for luminescence centers in Eu,Si-codoped AlN, Eu-doped β-sialon, and Mn-doped γ-AlON.