RE-activated lanthanide phosphate phosphors for PDP applications

Several mechanisms have been proposed for the degradation of currently available plasma display panel (PDP) phosphors. The proposed mechanisms for degradation include bombardment by energetic ions, low-energy electrons and high-energy photons (VUV) from the Xe/Ne gas discharge. The limited lifetime exhibited by some of the PDP phosphors lead us to explore different rare earth-activated lanthanide phosphate phosphors, which may have improved lifetime and luminance efficiency for PDP applications. Compared to silicate, borate- and oxide-based standard PDP phosphors, the excitation spectra of lanthanum phosphate-based phosphors exhibit high absorption in VUV region (100-200 nm). A number of phosphate samples have been prepared by calcinating required quantities of respective rare earth nitrates in the presence of ammonium hydrogen phosphate and flux at solid stare reaction temperatures, Various preparative conditions are considered to improve the overall efficiency and morphology. The excitation (VUV region) and emission spectra (UV-visible) from various RE-doped lanthanide phosphate phosphors samples are presented. The feasibility of employing these phosphors in PDP applications has been described. (C) 2000 Elsevier Science B.V. All rights reserved.