The present invention provides an oxide-base scintillator single crystal having an extremely large energy of light emission, adoptable to X-ray CT and radioactive ray transmission inspection apparatus, and more specifically to provide a Pr-containing, garnet-type oxide single crystal, a Pr-containing perovskite-type oxide single crystal, and a Pr-containing silicate oxide single crystal allowing detection therefrom light emission supposedly ascribable to 5d-4f transition of Pr.

An illumination module includes a light mixing cavity with an interior surface area and window that are physically separated from an LED. A portion of the window is coated with a first wavelength converting material and a portion of the interior surface area is coated with a second wavelength converting material. The window may be coated with LuAG:Ce. The window may also be coated with a third wavelength converting material with a peak emission wavelength between 615-655 nm where the spectral response of light emitted from the window is within 20% of a blackbody radiator at the same CCT. The LED may emit a light that is converted by the light mixing cavity with a color conversion efficiency ratio greater than 130 lm/W where the light mixing cavity includes two photo-luminescent materials with a peak emission wavelengths between 508-528 nm and 615-655 nm.

A strongly scattering optoceramic converter material having a density of less than 97% is provided, as well as a method for producing such an optoceramic material. By appropriately choosing in particular the composition, blending method, and sintering conditions, the production method permits to produce converter materials with tailored properties.

A light-emitting device 1 according to the present invention includes: a solid-state light-emitting element 10 that radiates laser light; and a wavelength converter 50 including plural types of phosphors which receive the laser light and radiate light. The phosphors included in the wavelength converter 50 are substantially composed of Ce.sup.3+-activated phosphors. The above-described light-emitting device includes at least a warm-color Ce.sup.3+-activated phosphor that receives the laser light and radiates light having a light emission peak within a wavelength range of 580 nm or more to less than 660 nm, and light-emitting components radiated by the phosphors are composed of only light-emitting components derived from Ce.sup.3+.

Provided is a wavelength conversion member in which the following are dispersed in a thermoplastic resin: a LuYAG fluorescent material that is represented by (Y.sub.1-α-βLu.sub.αCe.sub.β).sub.3Al.sub.5O.sub.12 (in which α is a positive number between 0.3-0.8 inclusive and β is a positive number between 0.01-0.05 inclusive), that emits yellow-green light as a result of excitation by blue light, and that has a diffraction peak within a range in which the diffraction angle 2θ in X-ray diffraction by the K.sub.α1 line of Cu is 52.9° to 53.2° inclusive; and a KSF fluorescent material that is represented by K.sub.2(Si.sub.1-xMn.sub.x)F.sub.6 (in which x is a positive number between 0.001 and 0.3 inclusive) and that emits red light as a result of excitation by blue light. The content of the KSF fluorescent material in the wavelength conversion member is 1 to 5 times the content of the LuYAG fluorescent material by mass ratio. The wavelength conversion member makes it possible to provide a light-emitting device that has small color deviation, that is suitable as a lighting device, that emits white light, and that has good color rendering properties in a color temperature range of 4,000-6,500K, i.e., the color temperature range from white to daylight color.

A light emitting device includes a light emitting element having a dominant wavelength in a range of 400 nm or more and 500 nm or less, and a wavelength conversion member that is arranged on a light emitting side of the light emitting element and includes a rare earth aluminate fluorescent material having a composition represented by the following formula (I), wherein the light emitting device emits light having a dominant wavelength in a range of 475 nm or more and 500 nm or less, and wherein the light emitting device emits light having an S/P ratio of 6.5 or less derived from the formula (1), which is the ratio of a luminous flux in scotopic vision relative to a luminous flux in photopic vision:
(Lu.sub.1-p-nLn.sub.pCe.sub.n).sub.3(Al.sub.1-mGa.sub.m).sub.5kO.sub.12  (I) wherein in the formula (I), Ln represents at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and the parameters k, m, n, and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050, and 0≤p≤0.30, respectively.

Provided is a fluorescent material having a composition of rare earth aluminum-gallate, which radiates light in not only a visible light region but also a near-infrared region and has improved light emission intensity in a near-infrared region. The fluorescent material has a composition of rare earth aluminum-gallate, including at least one rare earth element Ln selected from the group consisting of Y, Gd, Sc, Lu, and La; at least one element selected from Al and Ga; Ce; and Nd. When a total molar composition ratio 5 of Al and Ga is used as a basis, a total molar ratio of Ln, Ce, and Nd is 3; a molar ratio of Ce is a product of 3 and a value of a parameter x; a molar ratio of Nd is a product of 3 and a value of a parameter y. The parameter x is in a range of 0.03 or more and 0.015 or less. The parameter y is in a range of 0.002 or more and 0.06 or less.

A method for producing a ceramic conversion element and a light-emitting device are disclosed. In an embodiment the method includes providing at least four functional layers, each being a green body or a ceramic, wherein first functional layer is formed as a first luminous layer comprising an oxide and configured to at least partially convert light of a first wavelength range into light of a second wavelength range, wherein a second functional layer is formed as a second luminous layer comprising a nitride and configured to at least partially convert light of the first wavelength range into light of a third wavelength range, wherein a third functional layer is formed as a first intermediate layer, wherein the first intermediate layer comprises an oxide, wherein a fourth functional layer is formed as a second intermediate layer, and wherein the second intermediate layer comprises a nitride or an oxynitride.

Light emitting devices and LED-filaments comprise an excitation source (e.g. LED) and a photoluminescence material comprising a combination of a first narrow-band red photoluminescence material which generates light with a peak emission wavelength in a range 580 nm to 628 nm and a full width at half maximum emission intensity in a range 45 nm to 60 nm and a second narrow-band red photoluminescence material generates light with a peak emission wavelength in a range 628 nm to 640 nm and a full width at half maximum emission intensity in a range 5 nm to 20 nm. At least one of the first and second narrow-band red photoluminescence materials can comprise a narrow-band red phosphor or a quantum dot (QD) material.

A light emitting device includes a first light source containing a first light emitting element, and a second light source containing a second light emitting element and a second fluorescent material, the first light source emits light in a region that is demarcated in a chromaticity diagram of the CIE 1931 color coordinate system by a first straight line connecting a first point having x,y of 0.280, 0.070 in the chromaticity coordinate and a second point having x,y of 0.280, 0.500 in the chromaticity coordinate, a second straight line connecting the second point and a third point having x,y of 0.013, 0.500 in the chromaticity coordinate, a purple boundary extending from the first point toward a direction in which x decreases in the chromaticity coordinate, and a spectrum locus extending from the third point toward a direction in which y decreases in the chromaticity coordinate, in a light emission spectrum, a light emission intensity ratio I.sub.PM/I.sub.PL of a light emission intensity I.sub.PM at a wavelength of 490 nm with respect to a light emission intensity I.sub.PL at a maximum light emission peak wavelength of the first light emitting element is in a range of 0.22 or more and 0.95 or less, the second light source emits light having a color deviation duv from a blackbody radiation locus in a range of −0.02 or more and 0.02 or less measured according to JIS Z8725 with a correlated color temperature in a range of 1,500 K or more and 8,000 K or less in a chromaticity diagram of the CIE 1931 color coordinate system, and the light emitting device emits mixed color light of light emitted from the first light source and light emitted from the second light source.