Delayed luminescence of Ce3+ doped Y2SiO5

The aim of the present work was to study the luminescence properties of the Ce3+ (x(Ce) = 0.01) doped Y2SiO5. The compounds were prepared by a sol-gel reaction between yttrium and cerium nitrate hydrates as well tetraetoxysilane. The X-ray powder diffraction revealed that all samples were of the monoclinic high temperature X-2 form. Two strong luminescence bands were observed at 395 and 427 nm with decay times of 43 and 49 ns, respectively. In addition, two other weak bands with fine structure were observed at 484 and 577 nm. The decay times of the latter bands were about 700 and 800 mus, respectively. The excitation spectra had three bands at ca. 270, 300 and 360 nm. The weak emission bands at 484 and 577 nm were tentatively explained to be due to the Ce4+ charge transfer luminescence associated with oxygen vacancies created by the reducing preparation conditions. (C) 2003 Elsevier B.V. All rights reserved.