Emission color variation of (Ba,Sr)3BP3O12:Eu2+ phosphors for white light LEDs.
A series of alkaline earth borophosphate phosphors, (Ba,Sr)(3)BP(3)O(12) doped with Eu(2+) ions, were synthesized by a solid state reaction. Two emission bands at 465 nm and 520 nm were attributed to the f-d transitions of doped Eu(2+) ions occupying in two different cation sites in host lattices and emission color variation was observed by substituting the M(2+) sites, which was rationalized in terms of two competing factors of the crystal field strength and bond covalence. Green and bluish-white pc-LEDs were fabricated by combination of a 370 nm near-UV chip and composition-optimized Ba(3)BP(3)O(12):Eu(2+) and (Ba,Sr)(3)BP(3)O(12):Eu(2+) phosphors, respectively. The series of phosphors may serve as a promising green and bluish-white luminescent materials used in fabrication of near UV-based white pc-LEDs.
Kuo
Te-Wen
TW
Phosphors Research Laboratory and Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan, ROC.
Liu
Wei-Ren
WR
Chen
Teng-Ming
TM