VIOLET BLUE EMISSION FROM EPITAXIAL CERIUM OXIDE-FILMS ON SILICON SUBSTRATES/

Violet/blue photoluminescence was observed from epitaxial cerium oxide films on silicon substrates. The films were deposited on silicon (111 ) substrates under ultrahigh vacuum conditions using pulsed laser abla tion of a cerium oxide target and treated by rapid thermal annealing i n argon. High resolution transmission electron microscopy and x-ray di ffraction measurements indicated the formation of a single crystal cer ium oxide phase Ce6O11 different from CeO2 in the annealed films. The emission might be due to charge transfer transitions from the 4f band to the valence band of the oxide. (C) 1997 American Institute of Physi cs.