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)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.

The present invention relates to perylene bisimides with rigid 2,2-biphenoxy bridges which are useful in a wide variety of applications and to novel to perylene bisimides with rigid 2,2-biphenoxy bridges. The present invention also relates to the use of said compound(s) in color converters for improving the luminous efficacy of LEDs, to color converters and their use and to lighting devices comprising at least one LED or OLED and at least one color converter. The present invention also relates to a printing ink formulation for security printing comprising at least one perylene bisimide with rigid 2,2-biphenoxy bridges and security documents.

Red-emitting phosphors may comprise a nitride-based composition represented by the chemical formula M.sub.aSr.sub.bSi.sub.cAl.sub.dN.sub.eEu.sub.f, wherein: M is at least one of Mg, Ca, Sr, Ba, Y, Li, Na, K and Zn, and 0<a<1.0; 1.5<b<2.5; 4.0c5.0; 0d1.0; 7.5<e<8.5; and 0<f<0.1; wherein a+b+f>2+d/v and v is the valence of M. Furthermore, nitride-based red-emitting phosphor compositions may be represented by the chemical formula M.sub.xM.sub.2Si.sub.5-yAl.sub.yN.sub.8:A, wherein: M is Mg, Ca, Sr, Ba, Y, Li, Na, K and Zn, and x>0; M is at least one of Mg, Ca, Sr, Ba, and Zn; 0y0.15; and A is at least one of Eu, Ce, Tb, Pr, and Mn; wherein x>y/v and v is the valence of M, and wherein the red-emitting phosphors have the general crystalline structure of M.sub.2Si.sub.5N.sub.8:A.

A coated phosphor may comprise: phosphor particles comprised of a phosphor with composition (M)(A).sub.2S.sub.4: Eu, wherein: M is at least one of Mg, Ca, Sr and Ba; and A is at least one of Ga, Al, In, Y; a dense impermeable (pinhole-free) coating of an oxide material encapsulating individual ones of the phosphor particles. The coated phosphor is configured to satisfy one or more of the conditions: (1) under excitation by blue light, the reduction in photoluminescent intensity at the peak emission wavelength after 1,000 hours of aging at about 85 C. and about 85% relative humidity is no greater than about 30%; (2) the change in chromaticity coordinates CIE(y), CIE y, after 1,000 hours of aging at about 85 C. and about 85% relative humidity is less than about 510.sup.3; (3) said coated phosphor does not turn black when suspended in a 1 mol/L silver nitrate solution for at least two hours at 85 C.; (4) said coated phosphor does not turn black when suspended in a 1 mol/L silver nitrate solution for at least one day at 20 C.; and (5) said coated phosphor does not turn black when suspended in a 1 mol/L silver nitrate solution for at least 5 days at 20 C.

A phosphor composition is presented. The phosphor composition includes a solid solution of aluminum nitride and a complex oxide including europium and strontium, where an amount of oxygen in the solid solution is at least 0.4 weight percent and less than 1 weight percent. A lighting apparatus including a phosphor material including the phosphor composition is also provided.

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.

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.

Provided is a green phosphor having high conversion efficiency. The green phosphor is represented by the composition formula (Sr.sub.1-yCa.sub.y).sub.1-xGa.sub.2S.sub.4:Eu.sub.x (0.03x0.20 and 0<y1). A full width at half maximum of a diffraction peak corresponding to a (422) plane in an XRD pattern is less than 0.18.

A phosphor contains: a crystal represented by MGa.sub.2S.sub.4, where M includes at least one element selected from the group consisting of Ba, Sr, and Ca; and an element A that functions as a luminescent center, wherein diffraction peaks are observed in a range of 2?=27.6? or more and 28.3? or less and a range of 2?=28.45? or more and 28.75? or less in an X-ray diffraction pattern obtained through measurement that uses CuK? rays performed using an X-ray diffractometer. A method for producing a phosphor includes sintering an ingredient composition that contains a gallium element (Ga), a sulfur element (S), an element M, where the element M includes at least one selected from the group consisting of Ba, Sr, and Ca and an element A that functions as a luminescent center while a portion of the ingredient composition is melted. A light emitting device includes: a light emitting element that contains the above-described phosphor; and an excitation source.

The invention provides a lighting device (100) comprising: a first solid state light source (10), configured to provide UV radiation (11) having a wavelength selected from the range of 380-420 nm; a second solid state light source (20), configured to provide blue light (21) having a wavelength selected from the range of 440-470 nm; a wavelength converter element (200), wherein the wavelength converter element (200) comprises: a first luminescent material (210), configured to provide upon excitation with the blue light (21) of the second solid state light source (20) first luminescent material light (211) having a wavelength selected from the green and yellow wavelength range, and wherein the first luminescent material excitability for UV radiation (11) is lower than for blue light (21); and a second luminescent material (220), configured to provide upon excitation with the blue light (21) of the second solid state light source (20) second luminescent material light (221) having a wavelength selected from the orange and red wavelength range, and wherein the second luminescent material excitability for UV radiation (11) is lower than for blue light (21).