| abstract |
The red-light emitting phosphor is the chemical formula M (x / v) M ' 2 Si 5-x Al x N 8: comprising: a nitride-based composition represented by the RE, of the formula, M is at least one of the one having a valence v , A divalent or trivalent metal; M 'is at least one of Mg, Ca, Sr, Ba and Zn; RE is at least one of Eu, Ce, Tb, Pr and Mn; x satisfies 0.1? x? 0.4, the phosphor has the general crystalline structure M ' 2 Si 5 N 8 : RE, Al in place of Si in the crystalline structure is substituted, and M is located substantially in the crevice region . In addition, the phosphor results in a deviation of the chromaticity coordinates CIE x and y of about 0.03 or less for 1,000 hours of aging at 85 DEG C and 85% humidity. The phosphor also absorbs UV and blue radiation and emits light having a photoluminescence peak wavelength within the range of about 620 to 650 nm. |