AVS 53rd International Symposium
    Thin Film Thursday Sessions
       Session TF2-ThA

Paper TF2-ThA1
Cathodoluminescence Degradation of Y@sub 2@SiO@sub 5@:Ce Thin Films

Thursday, November 16, 2006, 2:00 pm, Room 2022

Session: Pulsed Laser Deposition of Thin Films
Presenter: J.J. Terblans, University of the Free State, South Africa
Authors: E. Coetsee, University of the Free State, South Africa
J.J. Terblans, University of the Free State, South Africa
H.C. Swart, University of the Free State, South Africa
Correspondent: Click to Email
The cathodoluminescence (CL) intensity of cerium-doped yttrium silicate (Y@sub 2@SiO@sub 5@:Ce) phosphor thin films, grown by pulsed laser deposition (PLD), were investigated for possible applications in low voltage field emission displays (FEDs). A thin layer of tin oxide (SnO@sub 2@) was ablated on the surface of some of the films in order to investigate the effect, of the coated layer, on the degradation of the CL intensity. Auger electron spectroscopy (AES), X-ray photo electron spectroscopy (XPS) and CL spectroscopy were used to monitor changes in the surface chemical composition and luminous efficiency of the thin films. AES and CL spectroscopy were done with 2 keV energy electrons and beam current densities between 26.3 mA.cm@super -2@ and 52.6 mA.cm@super -2@, in high vacuum and in oxygen pressures of 1x10@super -8@, 1x10@super -7@ and 1x10@super -6@ Torr. Residual gas mass analysis (RGA) showed that the adventitious C was removed from the surface as volatile gas species which is consistent with the electron stimulated surface chemical reaction (ESSCR) model. Tin oxide (SnO@sub 2@) coated thin films resulted in a lower but more stable CL intensity than the uncoated thin films with light emission from the rare earth, Ce@super 3+@, due to the 5d - 4f transition resulting in the characteristic double shoulder peak of Y@sub 2@SiO@sub 5@:Ce between 400 and 500 nm (blue light).