Luminescent properties and energy transfer studies of color-tunable LuBO3: Ce3+/Tb3+/Eu3+ phosphors.

A series of LuBO 3 : Ce 3+ /Tb 3+ /Eu 3+ phosphors were synthesized via solid state reaction. The Ce 3+ /Tb 3+ co-doped and Ce 3+ /Tb 3+ /Eu 3+ tri-doped phosphors absorb near UV light through 4 f -5 d transitions of Ce 3+ , followed by sensitized Tb 3+ green and Eu 3+ red emission. Decay curves investigations for samples with various Tb 3+ and Eu 3+ contents reveal the occurrence of Ce 3+ → Tb 3+ → Eu 3+ energy transfer. It is found that due to relative low Tb 3+ → Eu 3+ energy transfer rate, a high Tb 3+ content (>40%) is required for efficient Ce 3+ → Tb 3+ → Eu 3+ energy transfer. Emission color of LuBO 3 : Ce 3+ , Tb 3+ , Eu 3+ varies from blue through green to red with Ce 3+ /Tb 3+ /Eu 3+ ratio. The quantum efficiency of LuBO 3 : Ce 3+ , Tb 3+ green phosphor and LuBO 3 : Ce 3+ , Tb 3+ , Eu 3+ red phosphor is 50% and 30%, respectively. Green and red LED prototypes were fabricated. The results show that the obtained phosphors are potential candidates as down-converted phosphors for NUV LEDs. [ABSTRACT FROM AUTHOR]