A method of producing a light transmissive element includes providing a holding member including an upper surface and a plurality of holes, each of the plurality of holes having at least one inner lateral surface that is a substantially smooth surface and an opening in the upper surface of the holding member; filling the plurality of holes with a wavelength conversion member containing fluorescent particles and a light transmissive member such that the wavelength conversion member is in contact with the inner lateral surface of each of the plurality of holes; molding the wavelength conversion member; and taking out the wavelength conversion member from the holding member after the molding of the wavelength conversion member.

A light emitting device includes a first light emitting element including a rectangular first light extraction surface, a second light emitting element including a rectangular second light extraction surface and emitting light having an emission peak wavelength different from an emission peak wavelength of the first light emitting element, and a light-transmissive member covering the first light extraction surface and the second light extraction surface. The light-transmissive member includes a first light-transmissive layer facing the first light extraction surface and the second light extraction surface, a wavelength conversion layer located on the first light-transmissive layer, and a second light-transmissive layer located on the wavelength conversion layer. The first light-transmissive layer contains a first matrix and first diffusive particles. The wavelength conversion layer contains a second matrix and wavelength conversion particles. The second light-transmissive layer contains a third matrix and second diffusive particles.

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 phosphor composition of an embodiment and a light emitting device package including the same includes: a green phosphor excited by blue light to emit green light; a first red phosphor of a nitride series which is excited by the blue light and emits first red light; and a second red phosphor of a fluorine series which is excited by the blue light and emits second red light, and is capable of emitting white light without deterioration of optical characteristics at a high temperature while improving luminous flux and color reproduction rate as compared with a light emitting device package including a conventional phosphor composition.

Embodiments of the present invention provide a phosphor improved in the emission intensity maintenance ratio without impairing the emission intensity and further a light-emitting device employing that phosphor. The phosphor is activated by manganese and has a basic structure comprising at least one element selected from the group consisting of potassium, sodium and calcium; at least one element selected from the group consisting of silicon and titanium; and fluorine. In an IR absorption spectrum of the phosphor, the intensity ratio of the peak in 3570 to 3610 cm.sup.−1 to that in 1200 to 1240 cm.sup.−1 is 0.1 or less.

Briefly, in one aspect, the present invention relates to processes for producing a stabilized Mn.sup.4+ doped phosphor in solid form and a composition containing such doped phosphor. Such process may include combining a) a solution comprising at least one substance selected from the group consisting of: K.sub.2HPO.sub.4, an aluminum phosphate, oxalic acid, phosphoric acid, a surfactant, a chelating agent, or a combination thereof, with b) a Mn.sup.4+ doped phosphor of formula I in solid form, where formula I may be: A.sub.x [MF.sub.y]:Mn.sup.4+. The process can further include isolating the stabilized Mn.sup.4+ doped phosphor in solid form. In formula I, A may be Li, Na, K, Rb, Cs, or a combination thereof. In formula I, M may be Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof. In formula I, x is the absolute value of the charge of the [MF.sub.y] ion and y is 5, 6 or 7.

There is provided a fluoride phosphor composite including: fluoride phosphor core particles that may be expressed by the empirical formula A.sub.xMF.sub.y:Mn.sup.4+, wherein A may be at least one selected from the group consisting of Li, Na, K, Rb, and Cs, M may be at least one selected from the group consisting of Si, Ti, Zr, Hf, Ge, and Sn, the composition ratio (x) of A may satisfy 2≦x≦3, the composition ratio (y) of F may satisfy 4≦y≦7, each fluoride phosphor composite particle may be coated with a Mn-free fluoride coating. The Mn-free fluoride coating may have a thickness less than or equal to 35% of the size of each fluoride phosphor composite particle.

A liquid crystal display device includes: a liquid crystal display panel that includes red color filters, green color filters, and blue color filters; and an illumination device that illuminates the liquid crystal display panel with white light. The illumination device includes light-emitting elements that emit blue light, a green phosphor that absorbs a portion of the blue light emitted from the light-emitting elements and then emits green light, and a red phosphor that absorbs a portion of the blue light emitted from the light-emitting elements and then emits red light. The blue color filters are made of a colored material that contains a dye, and the chromaticity values x and y of the white light emitted from the illumination device satisfy the relationships 0.24<x and 0.24<y.

A process for preparing a Mn.sup.+4 doped phosphor of formula I

A.sub.x[MF.sub.y]:Mn.sup.+4   I

includes combining a first solution comprising a source of A and a second solution comprising H.sub.2MF.sub.6 in the presence of a source of Mn, to form the Mn.sup.+4 doped phosphor; wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; y is 5, 6 or 7; and
wherein a value of a Hammett acidity function of the first solution is at least −0.9.

Particles produced by the process may have a particle size distribution with a D.sub.50 particle size of less than 10 μm.

A method includes obtaining a potassium hexafluorosilicate (PFS)-based powder, obtaining a fluidization material, and mixing the PFS-based powder with the fluidization material to form a PFS-based mixture. The PFS-based mixture is configured to be mixed with a resinous material to form a flowing phosphor blend configured to be placed onto a light source to form a phosphor on the light source.