Structure and luminescent properties of CeO2:: rare earth (RE = Eu3+ and Sm3+) thin films

Luminescent thin films were fabricated using CeO2 as a host crystal and Eu3+ and Sm3+ as activators. The films were deposited on glass substrates by a spin-on/pyrolysis technique at temperatures up to 700 degreesC using ethanolic solutions of rare-earth acetates. A cubic fluorite-type CeO2 phase was formed at the deposition temperatures between 400 and 700 degreesC. Increases in the temperature promoted the grain growth of CeO2 and improved its crystallinity. Eu3+ was practically doped in the CeO2 lattice as indicated by a dominant magnetic-dipole D-5(0)-->F-7(1) transition in a site with inversion symmetry. The efficiency of ultraviolet light excitation at 330-340 nm was promoted by the charge transfer from O2- to Ce4+ and the subsequent energy transfer to Eu3+ in photoluminescence. Sm3+ doping was found to cause unusual emissions with a dominant (4)G(5/2)-->H-6(5/2) transition centered at 573 nm. (C) 2004 American Institute of Physics.