A wavelength conversion member, comprises: a substrate; a first wavelength conversion layer on the substrate, the first wavelength conversion layer containing a first phosphor and a first matrix; and a second wavelength conversion layer containing a second phosphor, first inorganic particles, and a second matrix. The first phosphor and the second phosphor convert at least part of the excitation light incident on the second main surface into first light having longer wavelengths than the excitation light. The first light is emitted from the second main surface of the second wavelength conversion layer. A volume Vp1 of the first phosphor, a volume Vw1 of the first wavelength conversion layer, a volume Vp2 of the second phosphor, and a volume Vw2 of the second wavelength conversion layer satisfy Vp1/Vw1>Vp2/Vw2.

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

A light source for emitting emitted light having an SPD comprising: (a) a plurality of light emitters including at least one violet solid-state emitter; (b) at least one phosphor; wherein said light emitters and said at least one phosphor being configured such that: at least 25% of the power within the SPD is in the range 390-420 nm, and the emitted light has a chromaticity which is within a Duv distance of less than 5 points from the Planckian locus.

A light source for emitting emitted light having an SPD comprising: (a) a plurality of light emitters including at least one violet solid-state emitter; (b) at least one phosphor; wherein said light emitters and said at least one phosphor being configured such that: at least 25% of the power within the SPD is in the range 390-420 nm, and the emitted light has a chromaticity which is within a Duv distance of less than 5 points from the Planckian locus.

A light-emitting device includes a light-emitting element for emitting primary light, and a wavelength conversion unit for absorbing part of the primary light and emitting secondary light having a wavelength longer than that of the primary light, wherein the wavelength conversion unit includes plural kinds of phosphors having light absorption characteristics different from each other, and then at least one kind of phosphor among the plural kinds of phosphors has an absorption characteristic that can absorb the secondary light emitted from at least another kind of phosphor among the plural kinds of phosphors.

Embodiments of the invention include a wavelength-converting material defined by AE.sub.3−x1−y+zRE.sub.3−x2+y−z[Si.sub.9-wAl.sub.w(N.sub.1−yC.sub.y).sup.[4](N.sub.16−z−wO.sub.z+w).sup.[12]]Eu.sub.x1,Ce.sub.x2, where AE=Ca, Sr, Ba; RE=Y, Lu, La, Sc; 0≦x1≦0.18; 0≦x2≦0.2; x1+x2 >0; 0≦y≦1; 0≦z≦3; 0≦w≦3.

An oxynitride phosphor powder contains α-SiAlON and aluminum nitride, obtained by mixing a silicon source, an aluminum source, a calcium source, and a europium source to produce a composition represented by a compositional formula: Ca.sub.x1Eu.sub.x2Si.sub.12−(y+z)Al.sub.(y+z)O.sub.zN.sub.16−z (wherein x1, x2, y and z are 0<x1≦3.40, 0.05≦x2≦0.20, 4.0≦y≦7.0, and 0≦z≦1), and firing the mixture.

The invention relates to Eu.sup.2+-activated phosphors, to a process of its preparation, the use of these phosphors in electronic and electro optical devices, such as light emitting diodes (LEDs) and solar cells and especially to illumination units comprising said magnesium alumosilicate-based phosphors.

The invention provides a method for providing a luminescent particle with a hybrid coating, the method comprising: (i) providing a luminescent core comprising a primer layer on the luminescent core; (ii) providing a main ALD coating layer onto the primer layer by application of a main atomic layer deposition process, the main ALD coating layer comprising a multilayer with two or more layers having different chemical compositions, and wherein in the main atomic layer deposition process a metal oxide precursor is selected from a group of metal oxide precursors comprising Al, Zn, Hf, Ta, Zr, Ti, Sn, Nb, Y, Ga, and V; (iii) providing a main sol-gel coating layer onto the main ALD-coating layer by application of a main sol-gel coating process, the main sol-gel coating layer having a chemical composition different from one or more of the layers of the multilayer.

A light source for emitting emitted light having an SPD comprising: (a) a plurality of light emitters including at least one violet solid-state emitter; (b) at least one phosphor; wherein said light emitters and said at least one phosphor being configured such that: at least 25% of the power within the SPD is in the range 390-420 nm, and the emitted light has a chromaticity which is within a Duv distance of less than 5 points from the Planckian locus.