Provided are light-emitting nanoparticles that exhibit light emission stability and light resistance and are less biologically toxic. The light-emitting nanoparticles contain a matrix material and a light-emitting substance included in the matrix material, wherein the matrix material contains a cationic element that is at least one member selected from the group consisting of Ti, Si, Ca, Al and Zr, and an anionic element that is at least one member selected from the group consisting of O and P; and the concentration of the light-emitting substance in the matrix material is set to a level that results in an average distance of 1.2 nm or more between pieces of the light-emitting substance.

To provide a light emitting device that has an excellent color rendering property and a high light emission efficiency, and a lightening fixture provided with the same. A light emitting device including a light emitting element having a light emission peak wavelength in a range of 430 nm or more and 470 nm or less, and a fluorescent member including two or more kinds of rare earth aluminate fluorescent materials including at least one kind selected from the group consisting of a first fluorescent material having a composition represented by the following formula (I) (Y.sub.3(Al,Ga).sub.5O.sub.12:Ce), a second fluorescent material having a composition represented by the following formula (II) (Lu.sub.3Al.sub.5O.sub.12:Ce), and a third fluorescent material having a composition represented by the following formula (III) (Y.sub.3Al.sub.5O.sub.12:Ce), a fourth fluorescent material having a composition represented by the following formula (IV) (A.sub.2[M1.sub.1-pMn.sup.4+.sub.pF.sub.6]), and a fifth fluorescent material having a composition represented by the following formula (V) ((Sr,Ca)AlSiN.sub.3:Eu).

Provided are: a composite of a silicate-based base material and a rare-earth compound, having high light-emitting intensity and capable of being used as light-emitting particles, light-emitting nanoparticle including the same, a cell detection method, a method for treating an animal, a medical device, and a method for producing the composite of a silicate-based base material and a rare-earth compound. This composite of a silicate-based base material and a rare-earth compound includes elemental silicon (Si) and elemental oxygen (O), the rare-earth compound comprising at least one selected from a chloride of a rare-earth element and a fluoride of a rare-earth element, the silicate-based base material having a solid .sup.29Si-NMR spectrum satisfying Q.sub.4/Q.sub.3 of 1.6 to 3.9 where Q.sub.4 represents a peak area derived from Si(OSi)4 and Q.sub.3 represents a peak area derived from HO—Si(OSi).sub.3.

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.

In order to suppress the chromaticity shift and corrosion associated with the deterioration of a sulfide phosphor particle, this phosphor sheet is produced using a phosphor particle-containing resin composition which comprises: covered phosphor particles; polymerizable compound; and a polymerization initiator. The covered phosphor particles are obtained by covering phosphor particles with silicon dioxide films, wherein among the phosphor particles, at least sulfide phosphor particles are covered with silicon dioxide films that contain a metal oxide powder. Thus, the phosphor sheet can be inhibited from emitting a sulfur-based gas, and exhibits a minimized chromaticity shift, even when the phosphor sheet is present in such a manner that the edge of the phosphor layer of the sheet is in an exposed state.

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%.

A light emitting device includes a light emitting element having a peak emission wavelength of 410 nm to 440nm and a phosphor member. The phosphor member includes a first phosphor having a peak emission wavelength of 430 nm to 500 nm and containing an alkaline-earth phosphate, a second phosphor having a peak emission wavelength of 440 nm to 550 nm and containing at least one of an alkaline-earth aluminate and a silicate containing Ca, Mg, and Cl, a third phosphor having a peak emission wavelength of 500 nm to 600 nm and containing a rare-earth aluminate, a fourth phosphor having a peak emission wavelength of 610 nm to 650 nm and containing a silicon nitride containing Al and at least one of Sr and Ca, and a fifth phosphor having a peak emission wavelength of 650 nm to 670 nm and containing a fluorogermanate.

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.

To provide an oxide fluorescent material that has a light emission peak wavelength in a wavelength range of from red light to near infrared light. The oxide fluorescent material has a composition encompassed in a compositional formula represented by the following formula (1):

(Li.sub.1-tM.sup.1.sub.t).sub.u(Ga.sub.1-vM.sup.2.sub.v).sub.5O.sub.w:Cr.sub.x,Ni.sub.y,M.sup.3.sub.z,  (1)

wherein in the formula (1), M.sup.1 represents at least one kind of an element selected from the group consisting of Na, K, Rb, and Cs; M.sup.2 represents at least one kind of an element selected from the group consisting of B, Al, Sc, In, and a rare earth element; M.sup.3 represents at least one kind of an element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta; and t, u, v, w, x, y, and z each satisfy 0≤t≤1.0, 0.7≤u≤1.6, 0≤v<1.0, 7.85≤w≤11.5, 0.05≤x≤1.2, 0≤y≤0.5, 0.25<x+y≤1.2, y<x, and 0≤z≤0.5.

A light emitting diode package includes: a housing; a light emitting diode chip arranged in the housing; a wavelength conversion unit arranged on the light emitting diode chip; a first fluorescent substance distributed inside the wavelength conversion unit and emitting light having a peak wavelength in the cyan wavelength band; and a second fluorescent substance distributed inside the wavelength conversion unit and emitting light having a peak wavelength in the red wavelength band, wherein the peak wavelength of light emitted from the light emitting diode chip is located within a range of 415 nm to 430 nm.