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)2SiO5 (0.1≤x≤0.4, y=0.05, 0.005) phosphors prepared by combustion synthesis and post-annealed at 1200 °C for different annealing times are reported. X-ray diffraction analysis revealed the formation of a (Lu,Y)2SiO5 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 λ=405 nm and λ=440 nm, both corresponding to the Ce3+ allowed transitions 2D3/2→2F5/2 and 2D5/2→2F7/2, 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.