A europium-doped β-sialon phosphor particle. When the element concentration of a Si atom on the surface portion of the particle that is obtained by analyzing a cross section of the phosphor particle by the energy dispersive X-ray analysis method is indicated by Ps [at %], and the element concentration of a Si atom near the center of the particle that is obtained by an analysis by the same method is indicated by Pc [at %], the Pc-Ps value is 3 at % or more.

An optical material includes, in mol.%: 50-75% SiO.sub.2, 5-25% Al.sub.2O.sub.3, 2.5-25% MgO, and 1-15% at least one lanthanoid, such that the at least one lanthanoid includes: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or oxides or fluorides thereof. An optical material includes at least one lanthanoid and at least one alkaline earth fluoride dopant, such that the at least one lanthanoid includes: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or oxides or fluorides thereof, and such that the at least one alkaline earth fluoride dopant comprises BeF.sub.2, MgF.sub.2, CaF.sub.2, SrF.sub.2, and BaF.sub.2.

Provided a method of producing a β-sialon fluorescent material having excellent emission intensity. The method includes providing a first composition containing aluminum, an oxygen atom, and a europium-containing silicon nitride, heat treating the first composition, contacting the heat-treated composition and a basic substance to obtain a second composition, and contacting the second composition resulting from contacting the heat-treated composition with the basic substance and an acidic liquid medium containing an acidic substance.

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.

An upconversion nanoparticle includes at least one host selected from LiYF.sub.4, NaY, NaYF.sub.4, NaGdF.sub.4, and CaF.sub.3, at least one sensitizer selected from Sm.sup.3+, Nd.sup.3+, Dy.sup.3+, Ho.sup.3+, and Yb.sup.3+ doped in the at least one host, and at least one activator selected from Er.sup.3+, Ho.sup.3+, Tm.sup.3+, and Eu.sup.3+ doped in the at least one host. The upconversion nanoparticle is designed using a calculation from first principles to absorb light in the near-infrared wavelength range whose stability is ensured. Further, a hyaluronic acid-upconversion nanoparticle conjugate, in which the upconversion nanoparticle as described above is bonded to hyaluronic acid, is provided to be used in various internal sites with a hyaluronic acid receptor, particularly enables targeting, and increases an internal retention period and biocompatibility thereof.

A lighting device including at least one light emitter to emit blue light, a green phosphor having an emission peak in a range of 500 nm to 550 nm, a yellow phosphor having an emission peak in a range of 550 nm to 600 nm, and a red phosphor having an emission peak in a range of 600 nm to 650 nm, in which the yellow phosphor and the red phosphor have different full widths at half maximum, and the full width at half maximum of the yellow phosphor is longer than that of the red phosphor, and, in an emission spectrum, an intensity of light emitted from the lighting device increases from 500 nm to 600 nm, and the intensity of light emitted from the lighting device at 700 nm is less than about 10% of the maximum intensity of light emitted from the lighting device.

A luminescent material is disclosed with emission in the near infrared wavelength range, the luminescent material including Sc.sub.1-x-yA.sub.yRE:Cr.sub.x, wherein MO=P.sub.3O.sub.9, BP.sub.3O.sub.12, SiP.sub.3O.sub.12; A=Lu, In, Yb, Tm, Y, Ga, Al, where 0≤x≤0.75, 0≤y≤0.9. A wavelength converting structure including the luminescent phosphor is also disclosed.

Scintillators that can support up to 20 MHz count rates, which is significantly faster than the required 100K counts/second needed for single crystal diffractometers and methods for fabricating them.

The invention relates to a method for treating a plant wherein an agrochemical composition is applied onto at least one part of said plant, wherein the plant is corn or soy and wherein the agrochemical composition comprises in a liquid medium: particles of at least one inorganic phosphor exhibiting: a maximum in the emission spectrum in the range of wavelengths between 400 nm and 500 nm; an absorption Abs in the visible range which is equal to or less than 15.0%, preferably equal to or less than 10.0%, even more particularly equal to or less than 3.0%; and an internal quantum efficiency (IQE) measured in the range of wavelengths between 300 nm and 410 nm which is equal to or greater than 50.0%, more particularly greater than 75.0%, even more particularly greater than 90.0%;
and optionally at least one biocide.

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%.