A method of manufacturing a light emitting device includes providing a package; disposing a light emitting element in a recess of the package; injecting a sealing material in the recess, the sealing material including fluorescent material particles and a binder, the fluorescent material particles including particles of fluoride fluorescent material that include a surface region and an inner region, both the surface region and the inner region having a composition including: tetravalent manganese ions, at least one element or compound selected from the group consisting of alkali metal elements and NH.sub.4.sup.+, and at least one element selected from the group consisting of Group 4 and Group 14 elements; sedimenting centrifugally the fluorescent material particles toward a bottom surface in the recess to form a sealing member that comprises a first sealing member portion and a second sealing member portion; and curing the binder to form a cured sealing member.

A method for producing a fluoride fluorescent material includes: subjecting a mixture that contains a fluoride compound in a liquid medium to a pressurization treatment and a heating treatment, the fluoride compound having a chemical composition represented by the following formula: A.sub.2[M.sub.1−aMn.sup.4+.sub.aF.sub.6]. A is at least one cation selected from the group consisting of K.sup.+, Li.sup.+, Na.sup.+, Rb.sup.+, Cs.sup.+and NH.sub.4.sup.+, M is at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and a is a number that satisfies 0 <a <0.2. The pressurization treatment is performed at a pressure of 1.5 MPa or higher.

A light source assembly for use in a display device used in conjunction with night vision gear is provided. The light source assembly includes a light emitting diode configured to generate light comprising visible light and does not emit near IR light. A phosphor body configured to absorb the blue light and emit white light which does not contain near IR. The phosphor body prevents near IR light c from saturating the night vision gear.

A light emitting diode package includes a light emitting diode chip disposed in a housing, a first phosphor configured to emit green light, and a second phosphor configured to emit red light. White light is configured to be formed by a synthesis of light emitted from the light emitting diode chip, the first phosphor, and the second phosphor. The second phosphor has a chemical formula of A.sub.2MF.sub.6:Mn.sup.4+, A is one of Li, Na, K, Rb, Ce, and NH.sub.4, and M is one of Si, Ti, Nb, and Ta, and the Mn.sup.4+of the second phosphor has a mole range of about 0.02 to about 0.035 times the M.

Provided is a hybridized perovskite quantum dot material. The quantum dot material comprises a kernel and surface ligands. The kernel is formed by R.sub.1NH.sub.3AB.sub.3 or (R.sub.2NH.sub.3).sub.2AB.sub.4, where R.sub.1 is methyl group, R.sub.2 is an organic molecular group, A is at least one selected from Ge, Sn, Pb, Sb, Bi, Cu and Mn, B is at least one selected from Cl, Br and I, A and B form a coordination octahedral structure, and R.sub.1NH.sub.3 or R.sub.2NH.sub.3 is filled in gaps of the coordination octahedral structure. The surface ligand is an organic acid or organic amine. The quantum dot material has a high fluorescence quantum yield.

According to some embodiments, a composite light source includes at least one blue light source having a peak wavelength in the range of about 400 nanometer (nm) to about 460 nm; at least one LAG phosphor; at least one narrow red down-converter; and wherein the composite light source has a Lighting Preference Index (LPI) of at least 120. Numerous other aspects are provided.

A light-emitting device includes a light-emitting element that emits blue light, a Mn.sup.2+-activated γ-AlON green phosphor, and a dispersing material in which the green phosphor is dispersed. The green phosphor has an in-crystal Mn concentration of 2.5 wt % or more. The shortest path of the blue light through the dispersing material is 1 mm long or shorter.

A coated phosphor comprises phosphor particles, wherein said phosphor particles comprise manganese-activated complex fluoride phosphors; and a coating on individual ones of said phosphor particles, said coating comprising a layer of carboxylic acid material encapsulating the individual phosphor particles.

A scintillator assembly for use in a CT imaging system is provided. The scintillator assembly includes a frame including a base, and a plurality of walls extending substantially perpendicular from the base, wherein the base and the plurality of walls define a plurality of pixel compartments, and granular scintillating material contained in at least some of the plurality of pixel compartments, wherein the granular scintillating material is configured to convert x-ray beams into light.

Phosphor-converted light emitting diodes comprising a blue or near-UV emitting semiconductor device, a yellow-green phosphor, and a red phosphor exhibit incandescent-like dimming behavior in that the Correlated Color Temperature of a white light output decreases with reduced brightness.