A light emission device including a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less; and a fluorescent member including a first fluorescent material having a light emission peak wavelength in a range of 510 nm or more and less than 580 nm, a second fluorescent material having a light emission peak wavelength in a range of 580 nm or more and 680 nm or less and a full width at half maximum of 15 nm or more and 100 nm or less, and a third fluorescent material having a light emission peak wavelength in a range of 600 nm or more and 650 nm or less and a full width at half maximum of 14 nm or less, and having a melanopic ratio (MR) value in a specified range at a certain correlated color temperature.

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image. A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 100° C. to the emission intensity at 25° C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.

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 quantum dot having a perovskite crystal structure and including a compound represented by Chemical Formula 1:
ABX.sub.3+α  Chemical Formula 1
wherein, A is a Group IA metal selected from Rb, Cs, Fr, and a combination thereof, B is a Group IVA metal selected from Si, Ge, Sn, Pb, and a combination thereof, X is a halogen selected from F, Cl, Br, and I, BF.sub.4, or a combination thereof, and α is greater than 0 and less than or equal to about 3; and wherein the quantum dot has a size of about 1 nanometer to about 50 nanometers.

There is provided a display backlight (604), including an excitation source (644) for generating blue light (650); and a wavelength converter (654) being a unitary construction including a combination of a wavelength selective filter layer (658) bonded to a photoluminescence layer (660), where the photoluminescence layer (658) includes a green photoluminescence material and a red photoluminescence material; and where the wavelength selective filter layer (658) is transmissive to blue light and reflective to green and red light.

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.

An embodiment provides a phosphor composition and a light emitting device package comprising the same, wherein the phosphor composition comprises green phosphor, amber phosphor, and red phosphor, wherein the amber phosphor is expressed as chemical formula Li.sub.m−2XSi.sub.12-m−nAl.sub.m+nO.sub.nN.sub.16-n:Eu.sup.2+, where 2≦m≦5, 2≦n≦10, 0.01≦X≦1. The light emitting element package of the embodiment can display white light having improved brightness and color rendering index.

The present invention provides a method for producing a fluoride fluorescent material, the method comprising: contacting potassium ions with first complex ions comprising tetravalent manganese ions and second complex ions comprising at least one member selected from the group consisting of elements belonging to Groups 4 and 14 of the Periodic Table in a liquid medium comprising hydrogen fluoride to obtain a dispersion containing fluoride particles represented by the following formula (I):
K.sub.2[M.sub.1−bMn.sup.4+.sub.bF.sub.6]  (I) wherein M is the at least one member selected from the group consisting of elements belonging to Groups 4 and 14 of the Periodic Table, and b satisfies the relationship: 0<b<0.2; adding a reducing agent to the dispersion; and contacting the fluoride particles in the dispersion to which the reducing agent is added with at least one of additional second complex ions and additional potassium ions in the presence of hydrogen fluoride to obtain a fluoride fluorescent material.

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 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.