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.

A light emitting device is disclosed and includes an emission source configured to emit a primary blue light and a wavelength-converting element configured to convert the primary blue light to a secondary light, where the wavelength-converting element including a red phosphor material having a peak emission wavelength that is less than 620 nm and a green phosphor material having a peak emission wavelength that is greater than 530 nm. The device may have a correlated color temperature (CCT) in the range of 1600K-2500K, may exhibit a melanopic/photopic ratio less than 0.25 and/or may exhibit a radiometric power fraction of light having a wavelength below 530 nm below 0.1.

A wavelength converter may include a phosphor layer and a filter layer where the filter layer may be directly attached to the phosphor layer. The wavelength converter may have an overall thickness ranging from 20 μm to 80 μm.

A light emitting device assembly and methods for preparing a wavelength converter and methods for preparing a light emitting device assembly are also disclosed.

A phosphor having the general formula EA.sub.7A.sub.2T1.sub.t1T2.sub.t2 T3.sub.t3N.sub.nO.sub.o:RE. EA is selected from the group of divalent elements. A is selected from the group of monovalent elements. T1 is selected from the group of trivalent elements. T2 is selected from the group of tetravalent elements. T3 is selected from the group of pentavalent elements. RE is an activator element. 16+3 t1+4 t2+5 t3−3n−2 o=0. t1+t2+t3=5; n+o=16; 0≤t1≤4; 0≤t2≤5; 0≤t3≤5; 0≤n≤9; 7≤o≤16.

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 invention relates to a conversion element comprising a wavelength-converting conversion material, a matrix material in which the conversion material is inserted, and a substrate on which the matrix material and the conversion material are directly arranged, the matrix material comprising at least one condensed sol-gel material selected from the following group: water glass, metal phosphate, aluminium phosphate, monoaluminium phosphate, modified monoaluminium phosphate, alkoxytetramethoxysilane, tetraethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, titanium alkoxide, silica sol, metal alkoxide, metal oxane or metal alkoxane, the conversion element being arranged in the beam path of a laser source, the conversion element being mounted in a mechanically immobile manner in relation to the laser source, and the radiation of the laser source being dynamically arranged in relation to the conversion element.

A disclosed light-emitting device may provide white light with a cyan gap coinciding with a melanopic sensitivity range and thus having reduced melanopic content. The disclosed light-emitting device may include a light source providing violet or blue light with a peak wavelength under 450 nanometers (nm). The disclosed light-emitting device may include at least one down-converter coupled to and located downstream of the light source and configured with a long-wavelength onset to convert the spectrum of the violet or blue light to generate white light with a spectral power content in a 447-531 nm wavelength range that is less than or equal to 10% of a total spectral power content in a 380-780 nm wavelength range. The disclosed light-emitting device may be incorporated in a light engine system that further includes a control system that controls a drive current to the light-emitting device.

A light emitting device is disclosed and includes an emission source configured to emit a primary blue light and a wavelength-converting element configured to convert the primary blue light to a secondary light having a correlated color temperature (CCT) in the range of 1600K-2500K and color rendering index (CRI) in the range of 40-60, the wavelength-converting element including a red phosphor material having a peak emission wavelength that is less than 620 nm and a green phosphor material having a peak emission wavelength that is greater than 530 nm. The device may exhibit a melanopic/photopic ratio of less than 0.25 and/or may exhibit a radiometric power fraction of light having a wavelength below 530 nm below .1.

Provided are a method for producing a ceramic sintered body having improved light emission intensity, a ceramic sintered body, and a light emitting device. The method for producing a ceramic sintered body comprises preparing a molded body that contains a nitride fluorescent material having a composition containing: at least one alkaline earth metal element M.sup.1 selected from the group consisting of Ba, Sr, Ca, and Mg; at least one metal element M.sup.2 selected from the group consisting of Eu, Ce, Tb, and Mn; Si; and N, wherein a total molar ratio of the alkaline earth metal element M.sup.1 and the metal element M.sup.2 in 1 mol of the composition is 2, a molar ratio of the metal element M.sup.2 is a product of 2 and a parameter y and wherein y is in a range of 0.001 or more and less than 0.5, a molar ratio of Si is 5, and a molar ratio of N is 8, and wherein the nitride fluorescent material has a crystallite size, as calculated by X-ray diffraction measurement using the Halder-Wagner method, of 550 Å or less, and calcining the molded body at a temperature in a range of 1,600° C. or more and 2,200° C. or less to obtain a sintered body.

A dimmable light source for emitting white overall radiation may include a dimmer and a light-emitting diode. The dimmer may vary a current intensity of a current for operating the light-emitting diode during the operation of the light source. The LED may include a semiconductor layer sequence to emit primary radiation, and the LED may further include a conversion element configured to at least partially convert the primary radiation into secondary radiation having a first emission band with a first emission maximum ranging from 400 nm to 500 nm and a second emission band with a second emission maximum ranging from 510 nm to 700 nm. A relative intensity of the first emission band may reduce with decreasing current intensity of the current for operating the LED, and a relative intensity of the second emission band may increase with decreasing current intensity of the current for operating the LED.