Cathodoluminescence degradation of Y2O3:Dy3+ nanophosphor for field emission displays

Cathodoluminescence (CL) degradation of Y2O3:Dy3+ nanophosphors prepared by the solution combustion method was explored for feasible applications in low voltage field emission displays (FEDs). Oxide materials are excellent candidates for FED fabrication due to their high melting points, chemical and radiation stability with long lifetimes, high color purity, and being environmentally friendly. Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) were used to monitor changes in the surface chemical composition and correlation fit with CL degradation. AES and CL spectroscopy (2 keV energy electrons and with a beam current of 15 mu A) measurements were done in high vacuum (1.5 x 10(-8) Ton) and oxygen pressures of 1 x 10(-7) and 5 x 10(-7) Ton. The Y2O3:Dy3+ nanophosphor showed strong yellow (572 nm) and relatively weaker blue (492 nm) CL emissions. These CL emissions increased as carbon (C) was depleted from the surface, and then it slightly decreased at a high electron dose in both the vacuum and oxygen atmospheres, for electron doses up to about 690 C/cm(2). The C was depleted from the surface due to electron stimulated reactions. No significant change in the chemical state of Y 3d was observed with XPS high resolution spectra for the postirradiation sample. The change in the CL intensity was, therefore, attributed to the depletion of C from the surface. Published by the AVS.