Provided is a quantum dot including a quaternary core including a first-first Group I element, a first-second Group III element, and a first-third Group VI element and not including Se, and a ternary shell surrounding at least a portion of the quaternary core.

A lighting apparatus includes light emitting elements having an emission peak wavelength of 400 to 510 nm, a first phosphor having an emission peak wavelength of 485 to 700 nm, a second phosphor having an emission peak wavelength of 510 to 590 nm, a third phosphor having an emission peak wavelength of 600 to 700 nm, and a color filter having transmittance for light with a wavelength of 600 to 730 nm that is 80% or more and transmittance for light with a wavelength of 410 to 480 nm that is 3% or more and 50% or less. The color filter transmits a part of light emitted from the first phosphor, at least a part of light emitted from the second phosphor, and at least a part of light emitted from the third phosphor. Light transmitted through the color filter is emitted to the outside.

A photoluminescent material including by weight a polymer matrix in a percentage comprised between 19.99% and 54.99%, a photoluminescent compound in a percentage comprised between 45% and 80%, porous silica in a percentage comprised between 0.01% and 1% and optionally a dye system and additives with a total percentage for the dye system and additives comprised between 0% and 15%. Also, an article made from or coated with this photoluminescent material.

A wavelength converting structure is disclosed, the wavelength converting structure including a spinel type SWIR phosphor material having emission wavelengths in the range of 1000 to 1700 nm, the SWIR phosphor material including AE.sub.1-x-zA.sub.z+0.5(x-y)D.sub.2+0.5(x-y)-z-u E.sub.zO.sub.4:Ni.sub.y,Cr.sub.u where AE=Mg, Zn, Co, or Be, or mixtures thereof, A=Li, Na, Cu, or Ag, or mixtures thereof, D=Ga, Al, B, In, or Sc, or mixtures thereof, and E=Si, Ge, Sn, Ti, Zr, or Hf, or mixtures thereof; where 0x1, 0<y0.1, 0z1, 0u0.2.

A composition can include a copper containing nanocrystal.

Apparatuses and methods as described herein can be used to grow a -Ga.sub.2O.sub.3 based single crystal using an Edge-defined film fed growth (EFG) method. The method can include bringing a seed crystal in contact with an alumina doped Ga.sub.2O.sub.3 base melt, pulling the seed crystal to grow the -Ga.sub.2O.sub.3 based single crystal, and cooling the -Ga.sub.2O.sub.3 based single crystal after it has reached a length that is greater than 40 mm. In one embodiment, the method includes growing the scintillation crystal without defects.

A polymer, a quantum dot composition, and a light-emitting device employing the same are provided. The polymer includes a first repeat unit that has a structure represented by Formula (I): ##STR00001##
wherein the definitions of R.sup.1, R.sup.2, A.sup.1, A.sup.2, A.sup.3, and Z.sup.1 and n are as defined in the specification.