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 fluorescent material comprises a compound having the general formula of:

[Lu.sub.1−a−c−d−2/3bY.sub.aΣ(Ln−1).sub.cΣ(Ln−2).sub.dM.sub.b].sub.3±δ[Al.sub.1−xGa.sub.x].sub.5(O.sub.1−1/2yX.sub.y).sub.12±1.5δ.

The fluorescent material is combined with other compounds to form a photo-luminescent composition. The fluorescent material and the composition containing the same have a lot of advantages, such as high brightness, high color rendering index, high stability, and low light decay.

An optoelectronic component and a method for producing an optoelectronic component are disclosed. In an embodiment an optoelectronic component includes a semiconductor layer sequence having an active region configured to emit radiation at least via a main radiation exit surface during operation and a self-supporting conversion element arranged in a beam path of the semiconductor layer sequence, wherein the self-supporting conversion element includes a substrate and subsequently a first layer, wherein the first layer includes at least one conversion material embedded in a matrix material, wherein the matrix material includes at least one condensed sol-gel material, wherein the condensed sol-gel material has a proportion between 10 and 70 vol % in the first layer, and wherein the substrate is free of the sol-gel material and the conversion material and mechanically stabilizes the first layer.

A lighting device is specified. The lighting device comprises a phosphor having the general molecular formula (MA).sub.a(MB).sub.b(MC).sub.c(MD).sub.d(TA).sub.e(TB).sub.f(TC).sub.g(TD).sub.h(TE).sub.i(TF).sub.j(XA).sub.k(XB).sub.l(XC).sub.m(XD).sub.n:E. In this case, MA is selected from a group of monovalent metals, MB is selected from a group of divalent metals, MC is selected from a group of trivalent metals, MD is selected from a group of tetravalent metals, TA is selected from a group of monovalent metals, TB is selected from a group of divalent metals, TC is selected from a group of trivalent metals, TD is selected from a group of tetravalent metals, TE is selected from a group of pentavalent elements, TF is selected from a group of hexavalent elements, XA is selected from a group of elements which comprises halogens, XB is selected from a group of elements which comprises O, S and combinations thereof, XC=N and XD=C and E=Eu, Ce, Yb and/or Mn. The following furthermore hold true: a+b+c+d=t; e+f+g+h+i+j=u; k+l+m+n=v; a+2b+3c+4d+e+2f+3g+4h+5i+6j−k−2l−3m−4n=w; 0.8≤t≤1; −3.5≤u≤4; 3.5≤v≤4; (−0.2) w≤0.2 and 0≤m<0.875 v and/or v≥l>0.125 v.

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.

A method of producing a fluorescent material that is capable of providing a light emitting device having excellent durability, a fluorescent material, and a light emitting device are provided. The method of producing the fluorescent material includes: preparing a calcined product having a chlorosilicate composition containing at least one element selected from the group consisting of Ca, Sr, and Ba, at least one element selected from the group consisting of Mg and Zn, at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, Si, O, and Cl; and bringing the calcined product in contact with a fluorine-containing substance and heat-treating the calcined product in an inert gas atmosphere at a temperature in a range of 200° C. or more and 450° C. or less.

A core-shell fluorescent material and a light source device using the same are disclosed. The core-shell fluorescent material includes a core and a shell for generating an emitting light with wavelength within 520 and 800 nm after absorbing an exciting light with wavelength within 370 and 500 nm. The core may include yellow, green or red fluorescent powder, and the shell includes manganese (IV)-doped fluoride compound. The light source device generally includes the core-shell fluorescent material, a radiation source, leads and a package. The leads provide current to the radiation source and cause the radiation source to emit radiation. The core-shell fluorescent material is coated on the package for receiving the radiation so as to generate a high quality emission served as the desired light source for the field of lighting and displaying.

The present invention relates to utilization of lanthanide time resolved fluorescence for determining silica concentration. In the method sample comprising silica is admixed with a reagent comprising a lanthanide (III) ion and optionally a chelating agent, silica in the sample is allowed to interact with the reagent comprising the lanthanide (III) ion, followed by exciting the sample and detecting a signal deriving from the lanthanide (III) ion, and determining the concentration of the silica in the sample by using the detected signal.

A method of producing a silicate fluorescent material, the method includes: providing a raw material mixture that contains an M source containing M, an Mg source, an Eu source, and an Si source, and optionally an Mn source, obtaining at least one core particle comprising a silicate fluorescent composition having a formula: (M.sub.1-cEu.sub.c).sub.3a(Mg.sub.1-dMn.sub.d).sub.bSi.sub.2O.sub.8, in which M is at least one element selected from the group consisting of Ca, Sr, and Ba, and a, b, c, and d are numbers respectively satisfying 0.93≤a≤1.07, 0.90≤b≤1.10, 0.016≤c≤0.090, and 0≤d≤0.22; using a chemical vapor deposition method, depositing aluminum oxide on surfaces of the at least one core particle; and heat treating at a temperature in a range of 210° C. to 490° C. in an oxygen-containing atmosphere.

A light-emitting system for healthy lighting, a light bar and a light fixture, wherein they are applied to the field of lighting and can emit white light with a color temperature range of 2700 K to 6500 K. A relative spectral power of the light-emitting system is set to be ϕ (λ), and a relative spectral power distribution of a solar spectral curve corresponding to the color temperature is set to be S (λ). The white light has a first characteristic waveband, and a wavelength region of the first characteristic waveband is 380-405 nm. The white light has a second characteristic waveband, and a wavelength region of the second characteristic waveband is 415-455 nm. The white light has a third characteristic waveband, and a wavelength region of the third characteristic waveband is 465-495 nm.