Luminescence properties of new red-emitting phosphor Li2Al2Si3O10:Eu3+ for near UV-based white LED

Eu3+ doped Li2Al2Si3O10 red phosphor was synthesized by the conventional high-temperature solid-state method. The crystal structure, morphology, luminescence properties, thermal stability and quantum efficiency were characterized. The powders show average particle size of 8 mu m. The optimum Eu3+ dopant concentration is 0.02 in Li2Al2Si3O10 host lattice. Luminescence quenching is attributed to electric dipole-dipole interaction and impurities. The emission intensity of the D-5(0) -> F-7(2) transition (615 nm) is dominant upon the strongest excitation at 394 nm (F-7(0) -> L-5(6) transition). The Li2Al2Si3O10: 0.02Eu(3+) phosphor can be excited by near-ultraviolet (n-UV) light and exhibits red emission with the CIE chromaticity coordinates of (0.6389, 0.3488) and color purity as high as 93%. The Li2Al2Si3O10: 0.02Eu(3+) phosphor also possesses good thermal stability with quenching energy barrier of 1803 cm -1. The fluorescence lifetime and quantum efficiency are 0.388 ms and 31.5%, respectively. The results suggest that the red phosphor Li2Al2Si3O10:Eu3+ can be used for n-UV excited white LEDs.