| 摘要 |
PURPOSE:To provide a phosphor having an improved luminance which is prevented from temp.-dependent quenching at high temps., by incorporating boron oxide and Al and(or) Ca oxide into a (La, Ce, Tb)PO4 phosphor. CONSTITUTION:Starting materials including lanthanum oxide, terbium oxide, cerium nitrate, phosphoric acid, ammonium borate and aluminum oxide are mixed together and fired to prepare a desired phosphor activated with terbium and having a compsn. represented by the formula (wherein 0.15<=alpha<=0.45; 0.1<=beta<=0.3; 0.8<=l<1; 0<m<=0.1; 0<n<=0.1; and X is Al or Ga). Since part of phosphate groups as the principal component of the phosphor is substd. with borate groups and aluminate and(or) gallate groups to suppress oxidation of Ce and Tb atoms., the phosphor has a high luminance and does not undergo temp.-dependent quenching even at 200 deg.C.
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