Provided is a phosphor sheet that, despite its simplified structure, is capable of preventing deterioration in phosphors. In one of embodiments, the phosphor sheet includes moisture vapor barrier films 12 and 13 and a phosphor layer 11 that is sandwiched between the moisture vapor barrier films 12 and 13 and that includes a sulfide-based phosphor. Each of the moisture vapor barrier films 12 and 13 has an edge portion that is sealed by a cover member 14. The above structure prevents moisture vapor from entering the phosphor layer 11 from the edge portions of the moisture vapor barrier films 12 and 13, and accordingly, prevents deterioration in the phosphor(s) included in the phosphor layer 11.

A semiconductor light emitting device includes an LED and an associated recipient luminophoric medium that includes respective first through fourth luminescent materials that down-convert respective first through fourth portions of the radiation emitted by the LED to radiation having respective first through fourth peak wavelengths. The first peak wavelength is in the green color range and the second through fourth peak wavelengths are in the red color range. The second and third luminescent materials each emit light having a full-width half maximum bandwidth of at least 70 nanometers, while the fourth luminescent material emits light having a full-width half maximum bandwidth of less than 60 nanometers. Embodiments that only include three luminescent materials are also disclosed.

A red phosphor including the composition represented by the following general formula.

(x-a)MgO.Math.(a/2)Sc.sub.2O.sub.3.Math.yMgF.sub.2.Math.cCaF.sub.2.Math.(1-b)GeO.sub.2.Math.(b/2)Mt.sub.2O.sub.3:zMn.sup.4+ where x, y, z, a, b, and c satisfy 2.0x4.0, 0<y<1.5, 0<z<0.05, 0a<0.5, 0<b<0.5, 0c<1.5, and y+c<1.5, and Mt is at least one element selected from the group consisting of Al, Ga, and In.

Phosphors comprising a nitride-based composition represented by the chemical formula: M.sub.(x/v)(M.sub.aM.sub.b)Si.sub.(cx)Al.sub.xN.sub.d:RE, wherein: M is a divalent or trivalent metal with valence v; M is at least one divalent metal; M is at least one trivalent metal; 2a+3b+4c=3d; and RE is at least one element selected from the group consisting of Eu, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb. Furthermore, the nitride-based composition may have the general crystalline structure of M.sub.aM.sub.bSi.sub.cN.sub.d, where Al substitutes for Si within the crystalline structure and M is located within the crystalline structure substantially at the interstitial sites.

A method of producing a thiogallate-based fluorescent material having a large particle diameter and an enhanced luminance, and a sulfite for a thiogallate-based fluorescent material are provided. The method of producing a thiogallate-based fluorescent material includes preparing a first solution containing at least one element M1 selected from the group consisting of strontium, beryllium, magnesium, calcium, barium and zinc, and at least one element M2 selected from the group consisting of europium and cerium, and a second solution containing a sulfite; simultaneously supplying the first solution and the second solution to a reaction vessel and causing a reaction in a reaction system to obtain a powder of a sulfite containing M1 and M2; and obtaining the thiogallate-based fluorescent material from the resulting powder of a sulfite containing M1 and M2.

The invention provides a lighting unit comprising a source of blue light, a source of green light, a first source of red light comprising a first red luminescent material, configured to provide red light with a broad band spectral light distribution, and a second source of red light comprising a second red luminescent material, configured to provide red light with a spectral light distribution comprising one or more red emission lines. Especially, the first red luminescent material comprises (Mg,Ca,Sr)AlSiN.sub.3:Eu and/or (Ba,Sr,Ca).sub.2Si.sub.5-xAl.sub.xO.sub.xN.sub.8-x:Eu, and the second red luminescent material comprises K.sub.2SiF.sub.6:Mn.

Disclosed herein is a method including disposing in a mold a powder that has a composition for manufacturing a scintillator material and compressing the powder to form the scintillator material; where an exit surface of the scintillator material has a texture that comprises a plurality of projections that reduce total internal reflection at the exit surface and that increase the amount of photons exiting the exit surface by an amount of greater than or equal to 5% over a surface that does not have the projections.

Disclosed herein is a method including disposing in a mold a powder that has a composition for manufacturing a scintillator material and compressing the powder to form the scintillator material; where an exit surface of the scintillator material has a texture that comprises a plurality of projections that reduce total internal reflection at the exit surface and that increase the amount of photons exiting the exit surface by an amount of greater than or equal to 5% over a surface that does not have the projections.

A red phosphor including the composition represented by the following general formula.
(xa)MgO.(a/2)Sc.sub.2O.sub.3.yMgF.sub.2.cCaF.sub.2.(1b)GeO.sub.2.(b/2)M.sub.2O.sub.3:zMn.sup.4+ where x, y, z, a, b, and c satisfy 2.0x4.0, 0<y<1.5, 0<z<0.05, 0a<0.5, 0<b<0.5, 0c<1.5, and y+c<1.5, and M is at least one element selected from the group consisting of Al, Ga, and In.

A phosphor indicated by general formula Me.sub.aRe.sub.bSi.sub.cAl.sub.dN.sub.eO.sub.f. In the formula: Me has Sr as an essential element thereof and can include one or more types of element selected from Na, Li, Mg, Ca, Ba, Sc, Y, and La; and Re has Eu as an essential element thereof and can include one or more types of element selected from Mn, Ce, Tb, Yb, and Sm. In addition, when a=1x, b=x, c=(2+2p)(1y), d=(2+2p)y, e=(1+4p)(1z), and f=(1+4p)z, parameters p, x, y, and z fulfill the following: 1.620<p<1.635, 0.005<x<0.300, 0.200<y<0.250, and 0.070<z<0.110. A light-emitting device with high luminance is provided by using this phosphor.