P‐51: Preparation of (Y,Gd)BO3:Eu3+ Phosphor with High Luminescent Efficiency by New Synthetic Method

Abstract

AbstractTo improve the luminescent efficiency of conventional (Y,Gd)BO3:Eu3+ red‐phosphor for the plasma display panel (PDP), we have developed a new synthetic method such that the stoichiometric amount of boric acid is reacted with small‐sized and spherical (Y,Gd)2O3:Eu3+ phosphor oxides prepared by thermal decomposition of urea. The sol‐gel method using citric acid as a complex‐networking and fuel agents was also applied to compare the difference in luminescent efficiency under the vacuum ultraviolet (VUV) excitation depending on the synthetic methods. In this study, the most efficient composition of orthoborate was determined to be (Y0.64Gd0.31)BO3:0.05Eu3+. Orthoborate phosphor materials prepared by this new synthetic method have exhibited more effective VUV absorption in the range from 140 nm to 180 nm, and thus higher emissive brightness under the PDP operating condition than those of commercial phosphor and materials prepared in sol‐gel method. It is proposed that the present new synthetic method can improve crystalline purity and spherical morphology of phosphor particles and thereby the luminescent efficiency.