Luminescent device

Abstract

This invention provides a luminescent device comprising a blue fluorescent substance-containing fluorescent substance layer. The fluorescent substance layer comprises, as a blue fluorescent substance, an aluminate fluorescent substance comprising Ba, Sr, Eu, Mg, Al and O as constituent elements at an atomic ratio of Ba : Sr : Eu : Mg : Al : O = p : q : r : 1 : w : 17, wherein 0.70 = p = 0.95, 0 = q = 0.15, 0.05 = r = 0.20, p + q + r = 1, and 9.8 = w = 10.5. When the aluminate fluorescent substance is subjected to X-ray crystal structure analysis on the assumption that the aluminate fluorescent substance belongs to a space group P63 / mmc, the aluminate fluorescent substance has a linear bond function s of not more than 1 as calculated by s = -11622 + 2043.07La + 199.24L1 - 116.91L2 wherein La represents a lattice constant, AA; L1 represents atomic distance between Al(2) and O(5), AA; and L2 represents atomic distance between Al(1) and O(4), AA.

Description

technical field [0001] The present invention relates to a light emitting device containing an aluminate phosphor as a blue phosphor in a phosphor layer. Background technique [0002] As a blue phosphor for light-emitting devices such as plasma display panels (PDPs), BaMgAl 10 o 17 :Eu, (Ba, Sr)MgAl 10 o 17 Alkaline-earth aluminate phosphors activated with europium called so-called BAM:Eu such as :Eu (hereinafter, may be simply referred to as "aluminate phosphors") have attracted attention. This is because it has excellent visible light emission characteristics when excited by vacuum ultraviolet rays, compared with other blue phosphors. [0003] Phosphor layers such as PDPs are produced by mixing phosphors and binders to prepare slurry, applying the slurry to the surface of a substrate such as glass, and then baking it. [0004] However, when an aluminate phosphor is used, the wavelength conversion efficiency may deteriorate significantly over time depending on the usage...

AI Technical Summary

Problems solved by technology

[0005] However, in the methods described in JP-A-61-254689 and JP-A-2000-34478, although a certain inhibitory effect on thermal deterioration that may occur during manufacture is obtained, aging and accompanying image degradation cannot be sufficiently suppressed. Deterioration of characteristics due to vacuum ultraviolet ray irradiation at the time of display

[0006] In addition, even if the method described in JP-A-10-330746 is used, it is difficult to uniformly cover the phosphor with the oxide film of Sb itself, and there is a problem that there is an inverse relationship between the chromaticity change and the luminance maintenance rate.

[0007] In addition, even if the technique described in JP-A-2002-180043 is used, for example, when heating at 50° C. in air for 15 minutes, the luminance is reduced by 5% or more, so the problem of deterioration of characteristics according to usage conditions cannot be solved.

[0008] In addition, in the PDP containing the above-mentioned aluminate phosphor in the phosphor layer, a problem called burning occurs.

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