Effect of temperature on the degradation of ZnSFED phosphors

Citation
Hc. Swart et al., Effect of temperature on the degradation of ZnSFED phosphors, SURF INT AN, 32(1), 2001, pp. 110-113
Citations number
13
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
SURFACE AND INTERFACE ANALYSIS
ISSN journal
01422421 → ACNP
Volume
32
Issue
1
Year of publication
2001
Pages
110 - 113
Database
ISI
SICI code
0142-2421(200108)32:1<110:EOTOTD>2.0.ZU;2-V
Abstract
The changes in cathodoluminescent brightness and changes in the surface che mistry of ZnS:Cu,Al,Au have been investigated using Auger electron spectros copy (AES) and a photospectrometer. The ZnS:Cu,Al,Au phosphor powders have been subjected to electron beam bombardment of 2 keV, with an electron beam current density of 88 mA cm(-2) at an oxygen pressure of 2 x 10(-6) Torr. The studies were carried out between room temperature and 310 degreesC. Deg radation was manifested by a non-luminescent ZnO layer that formed on the s urface of the phosphor according to the electron-stimulated surface chemica l reaction (ESSCR) mechanism. An increase in temperature led to a decrease in the surface reaction rate due to a decrease in the mean surface lifetime of the oxygen molecules on the surface, with a direct decrease in the ESSC R probability. Without the presence of the electron beam, no chemical react ions occurred on the surface up to 310 degreesC. Local heating due to the e lectron beam irradiation is not responsible for the chemical reactions on t he ZnS phosphor surface. Copyright (C) 2001 John Wiley & Sons, Ltd.