Unravelling the interplay of local structure and valence transitions in Ce-doped CaYAlO4 luminescent materials.

ABSTRACT

Cerium has been widely used as a dopant in luminescent materials due to its unique electronic configurations. It is generally anticipated that the luminescence properties of rare-earth-doped materials are closely related to the local environment of activators, especially for Ce3+ . In addition, it is convenient to modulate its emission wavelength by adjusting the composition and structure. In this study, we systematically analyzed the microstructure of the Ce-doped CaYAlO4 system at atomic resolution. The quantitive results indicated that the structure distortion greatly influenced the valence state of the Ce dopant, which is critical to its luminescence efficiency. In addition, valence variations also exist from surface to inner structure due to the big distortion area around the surface. Our results unravel the interplay of local structure and valence transitions in Ce-doped aluminate phosphors, which has the potential to be applied in other luminescent materials.