| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing a low-voltage blue-emitting phosphor having excellent luminance. SOLUTION: Equimolar amounts of ZnO and Ga2O3 and 5-20 g per mol of ZnO are mixed. The formed mixture is subjected to the primary firing at 1,100-1,300 deg.C in atmospheric air. By this firing step, a ZnO.Ga2O3 matrix is formed, and the matrix is doped with Li. The product from the primary firing is then milled to uniformly disperse agglomerates of matrix particles. The milled substance is washed with 0.5N nitric acid or about 1% hydrochloric acid to remove excessive flux. The washed substance is subjected to the secondary firing at 800-1,000 deg.C in a reducing atmosphere. By the secondary firing step, the crystallinity of the zinc gallate phosphor increases resulting in an increase in the luminous efficiency of the phosphor. The substance subjected to the secondary firing is classified to obtain a low-voltage blue-emitting phosphor.
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