Cathodoluminescence degradation of SiO{sub 2}:Ce,Tb powder phosphors prepared by a sol-gel process
- Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa)
Auger electron spectroscopy (AES), cathodoluminescence (CL) spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to study the CL intensity degradation of SiO{sub 2}:Cb,Tb powder phosphors prepared by a sol-gel process. The AES and the CL data were collected simultaneously when the powders were bombarded for 10 h with a beam of electrons of current density of 54 mA/cm{sup 2}, accelerated by 2 kV in a vacuum chamber containing either 1x10{sup -8} or 1x10{sup -7} Torr O{sub 2}. A decrease of CL intensity was simultaneous with desorption of oxygen (O) from the surface, i.e., there is a correlation between the degradation of CL intensity and desorption of O. The AES and the XPS data suggest that a nonluminescent oxygen-deficient layer of SiO{sub x} (x<2) that could decrease the CL intensity was formed on the surface. Mechanisms by which oxygen desorption leads to a reduction of the CL intensity are discussed.
- OSTI ID:
- 20979470
- Journal Information:
- Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 4 Vol. 25; ISSN 1553-1813
- Country of Publication:
- United States
- Language:
- English
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