Surface chemical reactions during electron beam irradiation of nanocrystalline CaS:Ce{sup 3+} phosphor

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3446828· OSTI ID:21476321

Kumar, Vinay; Pitale, Shreyas S; Nagpure, I M; Coetsee, E; Ntwaeaborwa, O M; Terblans, J J; Swart, H C ^[1]; Mishra, Varun ^[2]

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1. Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa)
2. Department of Physics, Lovely Institute of Engineering-POLY, Lovely Professional University, Phagwara 144 402, Punjab (India)

The effects of accelerating voltage (0.5-5 keV) on the green cathodoluminescence (CL) of CaS:Ce{sup 3+} nanocrystalline powder phosphors is reported. An increase in the CL intensity was observed from the powders when the accelerating voltage was varied from 0.5 to 5 keV, which is a relevant property for a phosphor to be used in field emission displays (FEDs). The CL degradation induced by prolonged electron beam irradiation was analyzed using CL spectroscopy, x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The AES data showed the decrease in the S peak intensity and an increase in the O peak intensity during electron bombardment. The CL intensity was found to decrease to 30% of its original intensity after about 50 C/cm{sup 2}. XPS was used to study the chemical composition of the CaS:Ce{sup 3+} nanophosphor before and after degradation. The XPS data confirms that a nonluminescent CaSO{sub 4} layer has formed on the surface during the degradation process, which may partially be responsible for the CL degradation. The electron stimulated surface chemical reaction mechanism was used to explain the effects of S desorption and the formation of the nonluminescent CaSO{sub 4} layer on the surface.

• OSTI ID: 21476321
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 107; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
ALKALINE EARTH METAL COMPOUNDS
AUGER ELECTRON SPECTROSCOPY
BEAMS
CALCIUM COMPOUNDS
CALCIUM SULFATES
CALCIUM SULFIDES
CATHODOLUMINESCENCE
CERIUM IONS
CHALCOGENIDES
CHARGED PARTICLES
CRYSTALS
DESORPTION
ELECTRIC POTENTIAL
ELECTRON BEAMS
ELECTRON SPECTROSCOPY
EMISSION
ENERGY RANGE
FIELD EMISSION
IONS
IRRADIATION
KEV RANGE
LAYERS
LEPTON BEAMS
LUMINESCENCE
NANOSTRUCTURES
OXYGEN COMPOUNDS
PARTICLE BEAMS
PHOSPHORS
PHOTOELECTRON SPECTROSCOPY
PHOTON EMISSION
SORPTION
SPECTROSCOPY
SULFATES
SULFIDES
SULFUR COMPOUNDS
X-RAY PHOTOELECTRON SPECTROSCOPY