A wavelength conversion member comprises: a substrate; and a wavelength conversion layer. The wavelength conversion layer contains a first phosphor and a second phosphor. The second phosphor has a higher thermal conductivity than the first phosphor. In the wavelength conversion layer, a volume of the second phosphor is larger than a volume of the first phosphor. The wavelength conversion layer includes a first portion and a second portion. The first portion is located closer to the substrate than the second portion, and is in direct contact with the second portion. Thicknesses of the first portion and the second portion are equal to each other. A volume V11 of the first phosphor in the first portion, a volume V12 of the second phosphor in the first portion, a volume V21 of the first phosphor in the second portion, and a volume V22 of the second phosphor in the second portion satisfy V11/V12<V21/V22.

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.

Disclosed is a light emitting lamp bead, in which a blue light missing portion is effectively filled by means of a chip excitation phosphor combination having the waveband of 400 nm-415 nm, and phosphors also has strong absorption for purple light, so that a light emitting diode (LED) device having high light emitting efficiency may be obtained. For the waveband of 420 nm-460 nm, a blue phosphor also achieves emission; however, because the phosphors have broad peak emission, the intensity is weak with respect to a blue light excitation position, so that the harm of blue light is reduced.

Provided herein are phosphors of the general molecular formula:

(A.sub.2-2xEu.sub.x(Mg.sub.1-yCa.sub.y)PO.sub.4F

wherein the variables are as defined herein. Methods of producing the phosphors are also provided. In some aspects, the present disclosure provides light-emitting devices comprising these phosphors.

An oxide fluorescent material comprises: at least one first element M.sup.1 selected from Li, Na, K, Rb, and Cs; at least one second element M.sup.2 selected from Mg, Ca, Sr, Ba, and Zn; at least one third element M.sup.3 selected from B, Al, Ga, In, and rare earth elements; at least one fourth element M.sup.4 selected from Si, Ti, Ge, Zr, Sn, Hf, and Pb; O; and Cr, wherein when the molar ratio of the at least one fourth element M.sup.4 in 1 mol of the composition is 5, the molar ratio of the at least one first element M.sup.1 is 0.7 or more and 1.3 or less, the molar ratio of the at least one second element M.sup.2 is 1.5 or more and 2.5 or less, the molar ratio of the at least one third element M.sup.3 is 0.7 or more and 1.3 or less, the molar ratio of oxygen is 12.9 or more and 15.1 or less, and the molar ratio of Cr is more than 0 and 0.2 or less, and wherein the oxide fluorescent material has a light emission peak wavelength in a range of 700 nm or more and 1,050 nm or less in a light emission spectrum of the oxide fluorescent material.

A nitride phosphor having a composition containing Eu, Si, Al, N, and a group 2 element including at least one selected from the group consisting of Mg, Ca, Sr, and Ba. In the composition, a ratio of a total molar content of the group 2 element and Eu to a molar content of Al is 0.8 or more and 1.1 or less, a molar ratio of Eu is 0.002 or more and 0.08 or less, a molar ratio of Si is 0.8 or more and 1.2 or less, and a total molar ratio of Si and Al is 1.8 or more and 2.2 or less. The nitride phosphor has a first peak in a range of 17° 2θ or more and 19° 2θ or less and a second peak in a range of 34° 2θ or more and 35.5° 2θ or less in a CuKα powder X-ray diffraction pattern.

The halophosphate phosphor includes a halophosphate including an alkaline earth metal including at least calcium; europium; and a halogen including at least chlorine. An elution amount of chlorine ions after the halophosphate phosphor is brought into contact with 10 times by mass of pure water at 85° C. for five hours is 7 ppm or less.

A method of forming a nitridophosphate is disclosed, the method including forming a precursor mixture by combining a metal source material, a phosphorus source material, and a nitrogen source material, and heating the precursor mixture at a maximum temperature between 800° C. and 1300° C. in an atmosphere including nitrogen gas at a pressure between 2 MPa and 500 MPa.

A fluorescent member includes: a wavelength converter including an incidence part on which a light of a light source is incident and an output part from which a converted light subjected to wavelength conversion as a result of excitation by an incident light is output; and a reflecting part provided in at least a portion of a surface of the wavelength converter. The wavelength converter is comprised of a material whereby a degree of scattering of the light of the light source incident via the incidence part and traveling toward the output part is smaller than in the case of a polycrystalline material.

A white light emitting device, a light bar and a light apparatus. A relative spectrum of the white light emitting device is ϕ(λ). A relative spectrum of a black body radiation with a corresponding color temperature is S(λ). An area normalization is performed on φ(λ) and S(λ) to convert an equal energy spectrum φ′(λ) of the white light emitting device and an equal energy spectrum S′(λ) of the black body radiation with the corresponding color temperature. A degree of similarity R of the equal energy spectrum of the white light emitting device and the equal energy spectrum of the black body radiation satisfies the following formula:

[00001]$R=1-\frac{{\Sigma }_{\lambda i}^{\lambda n}.Math.S^{\prime }\left(\lambda \right)-{\Phi }^{\prime }\left(\lambda \right).Math.}{{\Sigma }_{\lambda i}^{\lambda n}{S}^{\prime }\left(\lambda \right)},$

when λi is 380 nm, λn is 680 nm, R≥85%.