Review on electron stimulated surface chemical reaction mechanism for phosphor degradation

H. C. Swart, J. J. Terblans, E. Coetsee, O. M. Ntwaeaborwa, M. S. Dhlamini, S. Nieuwoudt, P. H. Holloway

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Standard cathodoluminescent phosphors normally lose brightness upon bombardment with electron beams. A combination of techniques such as x-ray photoelectron spectroscopy, Auger electron spectroscopy, and cathodoluminescence (CL) spectroscopy was used to show that the main reason for the degradation in CL intensity is the formation of a nonluminescent "dead layer" on the surface due to an electron stimulated surface chemical reaction. The decrease in luminance was found to be a result of the growth of the dead layer. Different phosphors which include sulfide-based as well as oxide-based phosphors reacted similarly under electron bombardment. When ZnS phosphor powder was exposed to the electron beam in a water-rich O2 ambient, a chemically limited ZnO layer was formed on the surface. A layer of ZnS O4 was formed on the surface during the electron beam degradation of the ZnS phosphor powder in a dry O2 ambient. The electron stimulated reaction led to the formation of a luminescent Si O2 layer on the surface of the Y2 Si O5: Ce phosphor powder. An increase in the CL intensity at a wavelength of 650 nm was measured during the formation of a luminescent Si O2 layer.

Original languageEnglish
Pages (from-to)917-921
Number of pages5
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number4
Publication statusPublished - 2007
Externally publishedYes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


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