Synthesis and characterization of (Lu1-x-yYxCey)2SiO5 luminescent powders with fast decay time

The structural and luminescent properties of blue-emitting (Lu1-x-yYxCey)(2)SiO5 (0.1 <= x <= 0.4, y=0.05, 0.005) phosphors prepared by combustion synthesis and post-annealed at 1200 degrees C for different annealing times are reported. X-ray diffraction analysis revealed the formation of a (Lu,Y)(2)SiO5 solid solution as a majority phase with small traces of a residual phase that was identified as Lu2SiO7. Under long-UV excitation, the powders yield a very bright blue-emission consisting of two bands with maximum emissions located at lambda=405 nm and lambda=440 nm, both corresponding to the Ce3+ allowed transitions D-2(3/2)-> F-2(5/2) and D-2(5/2)-> F-2(7/2), respectively. Moreover, luminescence decay times of 38-45 ns were measured, which depend on the composition, making these powders excellent candidates for application as scintillators in medical imaging. (c) 2012 Elsevier B.V. All rights reserved.