A coated phosphor comprises: phosphor particles comprised of a phosphor with composition MSe.sub.1xS.sub.x:Eu, wherein M is at least one of Mg, Ca, Sr, Ba and Zn and 0<x<1.0; and a coating on individual ones of the phosphor particles, the coating comprising a layer of oxide material encapsulating the individual phosphor particles; wherein the coated phosphor is configured such that under excitation by a blue LED the reduction in photoluminescent intensity at the peak emission wavelength after 1,000 hours of aging at about 85 C. and about 85% relative humidity is no greater than about 15%; and wherein the coated phosphor is configured such that the change in chromaticity coordinates CIE(x), x, after 1,000 hours of aging at about 85 C. and about 85% relative humidity is less than or equal to about 510.sup.3.

A display backlight, comprises: an excitation source, LED (146), for generating blue excitation light (148) with a peak emission wavelength in a wavelength range 445 nm to 465 nm; and a photoluminescence wavelength conversion layer (152). The photoluminescence wavelength conversion layer (152) comprises a mixture of a green-emitting photoluminescence material with a peak emission in a wavelength range 530 nm to 545 nm, a red-emitting photoluminescence material with a peak emission in a wavelength range 600 nm to 650 nm and particles of light scattering material.

This disclosure concerns a method of making a ligand for Quantum Dot functionalization, a method of making a functionalized Quantum Dot (QD) with a ligand, and a method of making a transparent luminescent quantum dot thiol-yne nanocomposite with tailorable optical, thermal, and mechanical properties. The prepolymer solution and functionalized Quantum Dot can be used in additive manufacturing.

A coated phosphor comprises: phosphor particles comprised of a phosphor with composition MSe.sub.1-xS.sub.x:Eu, wherein M is at least one of Mg, Ca, Sr, Ba and Zn and 0<x<1.0; and a coating on individual ones of the phosphor particles, the coating comprising a layer of oxide material encapsulating the individual phosphor particles; wherein the coated phosphor is configured such that under excitation by a blue LED the reduction in photoluminescent intensity at the peak emission wavelength after 1,000 hours of aging at about 85 C. and about 85% relative humidity is no greater than about 15%; and wherein the coated phosphor is configured such that the change in chromaticity coordinates CIE(x), x, after 1,000 hours of aging at about 85 C. and about 85% relative humidity is less than or equal to about 510.sup.3.

A light emitting device (LED-Filament) comprises: a light-transmissive substrate; at least one blue LED chip mounted on the light-transmissive substrate, for instance mounted on a face thereof; and a photoluminescence material at least partially covering the at least one blue LED chip. The photoluminescence material comprises narrow-band red phosphor particles that generates light with a peak emission wavelength in a range of 600 nm to 640 nm and a full width at half maximum emission intensity of 50 nm to 60 nm. The light emitting device is characterized by CRI Ra greater than or equal to about 90. The narrow-band red phosphor particles can comprise at least one Group IIA/IIB selenide sulfide-based phosphor material such as for example CaSe.sub.1-x S.sub.x:Eu (CSS phosphor). The LED-filament can be incorporated in a lamp, with a yellow to green-emitting phosphor that generates light with a peak emission wavelength in a range of 520 nm to 570 nm, to provide light with a color temperature in a range of 1500 K to 4000 K or 1500 K to 6500 K and a General Color Rendering Index (CRI Ra) greater than or equal to about 90 and a CRI R9 greater than or equal to about 50.

The invention provides a lighting device (100) comprising: a first solid state light source (10), configured to provide UV radiation (11) having a wavelength selected from the range of 380-420 nm; a second solid state light source (20), configured to provide blue light (21) having a wavelength selected from the range of 440-470 nm; a wavelength converter element (200), wherein the wavelength converter element (200) comprises: a first luminescent material (210), configured to provide upon excitation with the blue light (21) of the second solid state light source (20) first luminescent material light (211) having a wavelength selected from the green and yellow wavelength range, and wherein the first luminescent material excitability for UV radiation (11) is lower than for blue light (21); and a second luminescent material (220), configured to provide upon excitation with the blue light (21) of the second solid state light source (20) second luminescent material light (221) having a wavelength selected from the orange and red wavelength range, and wherein the second luminescent material excitability for UV radiation (11) is lower than for blue light (21).

This disclosure concerns a method of making a ligand for Quantum Dot functionalization, a method of making a functionalized Quantum Dot (QD) with a ligand, and a method of making a transparent luminescent quantum dot thiol-yne nanocomposite with tailorable optical, thermal, and mechanical properties. The prepolymer solution and functionalized Quantum Dot can be used in additive manufacturing.

A light emitting device (LED-Filament) comprises: a light-transmissive substrate; at least one blue LED chip mounted on a face of the light-transmissive substrate; and a photoluminescence material at least partially covering the at least one blue LED chip. The photoluminescence material comprises phosphor particles of at least one Group IIA/IIB selenide sulfide-based phosphor material that generates red light with a peak emission wavelength in a range of 600 nm to 640 nm and a full width at half maximum emission intensity of 50 nm to 55 nm. The LED-filament can be incorporated in a lamp, with a yellow to green-emitting phosphor that generates yellow to green light with a peak emission wavelength in a range of 520 nm to 570 nm, to provide light with a color temperature in a range of 1500 K to 4000 K and a General Color Rendering Index (CRI Ra) of greater than or equal to 90 and a CRI R9 greater than or equal to 50.

A light emitting device (LED-Filament) comprises: a light-transmissive substrate; at least one blue LED chip mounted on a face of the light-transmissive substrate; and a photoluminescence material at least partially covering the at least one blue LED chip. The photoluminescence material comprises phosphor particles of at least one Group IIA/IIB selenide sulfide-based phosphor material that generates red light with a peak emission wavelength in a range of 600 nm to 640 nm and a full width at half maximum emission intensity of 50 nm to 55 nm. The LED-filament can be incorporated in a lamp, with a yellow to green-emitting phosphor that generates yellow to green light with a peak emission wavelength in a range of 520 nm to 570 nm, to provide light with a color temperature in a range of 1500 K to 4000 K and a General Color Rendering Index (CRI Ra) of greater than or equal to 90 and a CRI R9 greater than or equal to 50.

A light emitting device (LED-Filament) comprises: a light-transmissive substrate; at least one blue LED chip mounted on a face of the light-transmissive substrate; and a photoluminescence material at least partially covering the at least one blue LED chip. The photoluminescence material comprises phosphor particles of at least one Group IIA/IIB selenide sulfide-based phosphor material that generates red light with a peak emission wavelength in a range of 600 nm to 640 nm and a full width at half maximum emission intensity of 50 nm to 55 nm. The LED-filament can be incorporated in a lamp, with a yellow to green-emitting phosphor that generates yellow to green light with a peak emission wavelength in a range of 520 nm to 570 nm, to provide light with a color temperature in a range of 1500 K to 4000 K and a General Color Rendering Index (CRI Ra) of greater than or equal to 90 and a CRI R9 greater than or equal to 50.