Energy Transfer from Ce to Tb /Dy /Mn in Ca Ga(PO ) Phosphors: Synthesis, Structure and Tunable Multicolor Luminescent Properties.

A series of Ca Ga(PO ) :Ce /Tb /Dy /Mn phosphors with tunable color, in which Ce acts as the sensitizer, was synthesized. Energy transfer (ET) from Ce to Tb /Dy /Mn was investigated in detail. Tb /Dy /Mn single-doped Ca Ga(PO ) can exhibit green, yellow, and red emission, respectively. Incorporating Ce into a Tb /Dy /Mn single-doped Ca Ga(PO ) phosphor can remarkably promote the luminous efficiency of the Tb /Dy /Mn ions. This enhancement originates from an efficient ET from Ce to Tb /Dy /Mn . The ET was validated by luminescence spectra, decay dynamics, and schematic energy levels. Moreover, the intensity ratio of red emission of Mn to violet emission of Ce was analyzed based on energy-transfer and lifetime measurements. In Ce -Tb , Ce -Dy , and Ce -Mn doped Ca Ga(PO ) , the emitting color changed from violet to green, yellow, and red, respectively, which indicates the potential use of this new tunable phosphor in UV light-emitting diodes.