| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phosphor having very high emission intensity and to provide a luminescent device using the same. <P>SOLUTION: The phosphor is obtained by firing an Ln source compound (Ln contains ≥50 mol% La and may contain at least one element selected form Sc, Y, La, Gd, Lu and Bi), an S source compound and an Eu source compound under contact with three alkali metal sulfides of Li, Na and K. The phosphor has an emission intensity ratio I<SB>400</SB>/I<SB>max</SB>of ≥0.57, wherein I<SB>max</SB>is maximum emission intensity upon irradiation with excitation light in a wavelength range of 300-450 nm, and I<SB>400</SB>is emission intensity upon irradiation with excitation light of 400 nm wavelength. The phosphor has a crystal phase having a chemical composition of (Ln<SB>1-x</SB>Eu<SB>x</SB>)<SB>2</SB>O<SB>2</SB>S (0.07≤x≤0.35). The luminescent device having high emission intensity is obtained by using a first illuminant which emits light of 350-415 nm as an excitation source and the phosphor as a second illuminant. <P>COPYRIGHT: (C)2010,JPO&INPIT |
