Crystal structure dependence of the luminescence of rare earth ions (Ce3+, Tb3+, Sm3+) in Y2SiO5

The luminescence properties of Ce3+, Tb3+, Sm3+ and energy transfer from Ce3+ to Tb3+ were studied in two modifications of Y2SiO5 (low temperature X1 type and high temperature X2 type). The Ce3+ cation shows lower emission energy and larger Stokes shift in X1-Y2SiO5 than in X2-Y2SiO5, and the emission intensities of Ce3+, Tb3+, Sm3+ in the former are weaker than those in the latter. There exists an energy transfer from Ce3+ to Tb3+ in both types of Y2SiO5, and the transfer efficiency in X2 type is higher than that in X1 type. All of these results are discussed in relation to the crystal structure of Y2SiO5.