Energy Transfer from Ce3+ to Tb3+/Dy3+/Mn2+ in Ca9Ga(PO4)7 Phosphors: Synthesis, Structure and Tunable Multicolor Luminescent Properties

Abstract A series of Ca 9 Ga(PO 4 ) 7 :Ce 3+ /Tb 3+ /Dy 3+ /Mn 2+ phosphors with tunable color, in which Ce 3+ acts as the sensitizer, was synthesized. Energy transfer (ET) from Ce 3+ to Tb 3+ /Dy 3+ /Mn 2+ was investigated in detail. Tb 3+ /Dy 3+ /Mn 2+ single‐doped Ca 9 Ga(PO 4 ) 7 can exhibit green, yellow, and red emission, respectively. Incorporating Ce 3+ into a Tb 3+ /Dy 3+ /Mn 2+ single‐doped Ca 9 Ga(PO 4 ) 7 phosphor can remarkably promote the luminous efficiency of the Tb 3+ /Dy 3+ /Mn 2+ ions. This enhancement originates from an efficient ET from Ce 3+ to Tb 3+ /Dy 3+ /Mn 2+ . The ET was validated by luminescence spectra, decay dynamics, and schematic energy levels. Moreover, the intensity ratio of red emission of Mn 2+ to violet emission of Ce 3+ was analyzed based on energy‐transfer and lifetime measurements. In Ce 3+ ‐Tb 3+ , Ce 3+ ‐Dy 3+ , and Ce 3+ ‐Mn 2+ doped Ca 9 Ga(PO 4 ) 7 , 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.