Crystal Growth of Silicate Phosphors from the Vapor Phase

摘要

Well-crystallized Ba_2SiO_4:Eu~(2+) powders were grown on a substrate by the vapor phase reaction between a mixed powder (barium carbonate and europium oxide) and SiO gas. The vaporization of SiO occurs at 1400-1600℃ from the SiO_2 source (or SiO powder) in a reducing atmosphere. The formed SiO gas was transported by 95 vol Ar - 5 vol H_2 gas and reacted with the raw material powders. The emission intensity of the Ba_2SiO_4:Eu~(2+) phosphor synthesized by the new vapor phase technique is about 2.6 times higher than that of a conventional solid-state reaction sample.