Size dependence of luminescent properties for hexagonal YBO3 : Eu nanocrystals in the vacuum ultraviolet region

The vacuum ultraviolet (VUV) spectra of the nanosized YBO3:Eu crystals, which have already been prepared by a more facile sol-gel pyrolysis process at a relatively low annealing temperature in our previous work, were investigated and compared to the bulk synthesized by conventional solid-state reactions. In the emission spectra, the size dependence of color purity in YBO3:Eu under VUV irradiation is in good agreement with our previous results obtained under ultraviolet excitation, and a relatively better color purity could be obtained in the YBO3:Eu phosphors with a smaller particle size. Moreover, the VUV excitation spectra of nanocrystals are also distinctly different from those of the bulk and submicrosized samples. The size dependence of the Eu-O charge transfer process, the B3O99- ion absorption, and the Y-O excitonic transition, as well as the quenching concentration, were reported and discussed. (C) 2003 American Institute of Physics.Physics, AppliedSCI(E)EI50ARTICLE129783-97889