Energy transfer and luminescent properties of a green-to-red color tunable Tb3+, Eu3+ co-doped K2Y(WO4)(PO4) phosphor.

A color-tunable Tb 3+ , Eu 3+ co-doped K 2 Y(WO 4 )(PO 4 ) phosphor was prepared by solid-state method. The excitation peak wavelength of the resulting phosphor was 377 nm and the emission peak wavelengths were at 545 nm, attributed to the 5 D 4 → 7 F 5 transition of Tb 3+ , and at 613 mm, attributed to the 5 D 0 → 7 F 2 transition of Eu 3+ . Both cross relaxation and exchange interaction are responsible for the Tb 3+ → Eu 3+ energy transfer in K 2 Y(WO 4 )(PO 4 ): Tb 3+ , Eu 3+ system. The intensity ratio of the two peaks could be freely controlled by varying the Eu/Tb ratio, allowing color to be tuned over a wide range from green to red. [ABSTRACT FROM AUTHOR]