A phosphor according to the present disclosure includes a first crystal phase added with an activator agent, a second crystal phase higher in thermal conductivity than the first crystal phase, and a third crystal phase which is disposed between the first crystal phase and the second crystal phase, and is same in crystal structure as the first crystal phase, and is smaller in additive amount of the activator agent than the first crystal phase.

A light emitting device includes: a light emitting element having a light emission peak wavelength in a range of 380 nm or more and 470 nm or less, and a wavelength conversion member disposed on a light emission side of the light emitting device and comprising: a fluorescent material layer containing a fluorescent material excited by light emitted from the light emitting device, having a light emission peak wavelength in a range of 500 nm or more and 780 nm or less, and a band-pass filter layer disposed on a light emission side of the fluorescent material layer.

A light-emitting device is provided. The light-emitting device includes a light-emitting element having a peak light-emitting wavelength in the range of 440 nm to 470 nm, and a fluorescent member. The fluorescent member includes a first fluorescent material having a peak light-emitting wavelength in the range of 480 nm to less than 520 nm, a second fluorescent material having a peak light-emitting wavelength in the range of 520 nm to less than 600 nm, and a third fluorescent material having a peak light-emitting wavelength in the range of 600 nm to 670 nm. The light-emitting device has a ratio of an effective radiant intensity for melatonin secretion suppression to an effective radiant intensity for blue-light retinal damage of 1.53 to 1.70 when the light-emitting device emits light with a correlated color temperature of 2700 K to less than 3500 K; 1.40 to 1.70 when the light-emitting device emits light with a correlated color temperature of 3500 K to less than 4500 K; 1.40 to 1.70 when the light-emitting device emits light with a correlated color temperature of 4500 K to less than 5700 K; and 1.35 to 1.65 when the light-emitting device emits light with a correlated color temperature of 5700 K to 7200 K.

A phosphor element includes: a phosphor part having an incident face for excitation light, an opposing face opposing the incident face, and a side face, the phosphor part converting at least a part of the excitation light incident onto the incident face into a fluorescence and emitting the fluorescence from the incident face; an integral low refractive index layer on the side face and opposing face of the phosphor part and having a refractive index lower than that of the phosphor part; and an integral reflection film covering a surface of the low refractive index layer. The area of the incident face of the phosphor part is larger than the area of the opposing face.

A method for producing a rare earth aluminate fluorescent material, including: preparing, as raw materials, cerium oxide having a crystallite diameter in a range of 200 Å or more and 1,600 Å or less, a compound containing at least one kind of a rare earth element Ln selected from the group consisting of Y, La, Lu, Gd, and Tb, a compound containing Al, and depending on necessity a compound containing at least one kind of an element M1 selected from the group consisting of Ga and Sc, wherein a total molar ratio of the rare earth element Ln and cerium is 3, a total molar ratio of Al and the element M1 is a product of a parameter k in a range of 0.95 or more and 1.05 or less and 5, a molar ratio of cerium is a product of a parameter n in a range of 0.005 or more and 0.050 or less and 3, and a molar ratio of the element M1 is a product of a parameter m in a range of 0 or more and 0.02 or less, the parameter k, and 5; and subjecting a mixture of the raw materials to a heat treatment to provide a calcined product.

A color wheel according to an embodiment of the present invention comprises: a basic fluorescent body having a basic light-emitting wavelength; and at least one modified fluorescent body having at least one light-emitting wavelength different from the basic light-emitting wavelength, wherein the basic fluorescent body comprises Y.sub.3Al.sub.5O.sub.12 and the modified fluorescent body comprises Y.sub.3(Ga.sub.xAl.sub.(1-x)).sub.5O.sub.12:Ce in which gallium is doped on the basic fluorescent body

A wavelength converting structure is provided, the wavelength converting structure including an SWIR phosphor having emission wavelengths in the range of 1600-2200 nm, the SWIR phosphor comprising a structurally disordered garnet material, a sensitizer ion, and at least one rare earth emitter ion. Also provided is a luminescent material having emission wavelength in the range of 1600-2200 nm, the luminescent material including (Gd.sub.3-u-v-x-y-zLu.sub.xTm.sub.yHo.sub.zSc.sub.vRE.sub.u)[Sc.sub.2-a-bLu.sub.aCr.sub.bGa.sub.dAl.sub.e]{Ga.sub.3-cAl.sub.c}O.sub.12 with RE=La, Y, Yb, Nd, Er, Ce and 0≤u≤2, 0<v≤1, 0<x≤1, 0<y≤0.5, 0≤z≤0.05, 0<a≤1, 0<b≤0.3, 0≤c≤3, 0<d≤1.8, 0≤e≤1.8. An IR emitting device including the luminescent material may provide a broad-band emission in the wavelength range of 1600-2200 nm with a continuous emission spectrum over a spectral width of at least 500 nm.

A light emitting device includes a Chip Scale Packaged (CSP) LED, the CSP LED including an LED chip that generates blue excitation light; and a photoluminescence layer that covers a light emitting face of the LED chip, wherein the photoluminescence layer comprises from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the layer. The device/CSP LED can further include a further photoluminescence layer that covers the first photoluminescence and that includes a photoluminescence material that generates light with a peak emission wavelength from 500 nm to 650 nm.

According to one embodiment, a white light source includes a combination of a light emitting diode and phosphors. One of the phosphors is at least a cerium activated yttrium aluminum garnet-based phosphor. There is no light emission spectrum peak at which a ratio of a largest maximum value to a minimum value is greater than 1.9. The largest maximum value is largest among at least one maximum value present in a wavelength range of 400 nm to 500 nm in a light emission spectrum of white light emitted from the white light source. The minimum value is adjacent to the largest maximum value in a longer wavelength side of the light emission spectrum.

Provided is a wavelength converting composite member including: a disk-shaped substrate; a first wavelength converting member provided on the substrate and containing a first phosphor that radiates fluorescence due to a parity-forbidden transition; and a second wavelength converting member provided on the substrate and containing a second phosphor that radiates fluorescence due to a parity-allowed transition. The first wavelength converting member and the second wavelength converting member are disposed adjacent to each other along the circumferential direction of the substrate. The first wavelength converting member and the second wavelength converting member are provided on the substrate in such a way that the position of the center of gravity of the entirety of the first wavelength converting member and the second wavelength converting member is located on the rotation axis of the substrate. A light emitting device is provided with the wavelength converting composite member.