SIGNIFICANT REDUCTION OF CATHODOLUMINESCENT DEGRADATION IN SULFIDE-BASED PHOSPHORS

The degradation of cathodoluminescent (CL) brightness under prolonged electron-beam excitation of phosphors has been identified as one of th e outstanding critical issues for flat-panel field-emission displays. In this letter, we have demonstrated that a TaSi2 coating on Y2O2S:Eu3 + phosphors substantially inhibits the cathodoluminescent degradation characteristics without reducing its efficiency, The coating was depos ited by pulsed laser deposition of TaSi, targets onto a fluidized bed containing phosphor particles. Cathodoluminescent degradation experime nts conducted at 2 keV and at 150 mu A/cm(2), showed that the CL brigh tness decreased by more than 50% after a Coulomb load of 15 C/cm(2) th e uncoated material. In contrast, the TaSi2-coated phosphor powders sh owed much less degradation, with CL brightness only decreasing by appr oximately 12% after electron irradiation with the same dose. (C) 1998 American Institute of Physics.