The present disclosure describes luminescent solar concentrators that include photoluminescent nanoparticles. The photoluminescent nanoparticles include a semiconductor nanocrystal that sensitizes the luminescence of a defect. The defect can include, for example, an atom, a cluster of atoms, or a lattice vacancy. The defect can be incorporated into the semiconductor nanocrystal, adsorbed onto, or otherwise associated with the surface of the semiconductor nanocrystal.

Provided herein are lanthanide-containing upconverting nanoparticles, methods of their preparation, compositions, and methods of using the same. The polymers and compositions provided herein may be used, for example, in photodynamic therapy.

High security inkjet inks are made my milling two or more functional materials, such as invisible ultraviolet fluorescent dyes or pigments, infrared Anti Stokes upconverting pigments, infrared absorption and fluorescent dyes or pigments and iron oxide magnetic pigments, into a pigment dispersion. A wet media mill is used to mill the pigment dispersion until the average particle size is below 300 nm. The dispersion is combined with main components of an inkjet ink, such as deionized water, humectants, surfactants, polymer resin and biocides, to produce the high security inkjet ink.

The present disclosure relates to a fluorescent powder and a light-emitting device including the same. The fluorescent powder includes an inorganic compound. The inorganic compound contains components including an element M, an element A, an element D, an element E, and an element R. The element M is selected from Eu, Ce, Mn, Tb, Dy, and Tm, the element A is selected from Mg, Ca, Sr, and Ba, the element D is selected from B, Al, Ga, In, La, Gd, Sc, Lu, and Y, the element E is selected from Si, Ge, Zr, and Hf, and the element R is at least two elements selected from N, O, F, and Cl. In a powder X-Ray Diffraction (XRD) spectrum with CoK radiation, the inorganic compound at least has diffraction peaks within ranges of an Bragg angle (2) from 27.3 to 28.3, 29.7 to 30.7, 41.9 to 42.9, and 43.5 to 44.5.

An exemplary embodiment provides for a source of white light having at least one white light emitting device composed of a transparent glass/quartz chamber, a vacuum chamber including an optically active element, a spacer, a focusing lens, an IR laser diode, where the optically active element arranged in the vacuum chamber is a thin-layer oxide matrix doped with rare earth ions selected from the group of Nd, Yb, the concentration of dopant ions being in the range of 0.0001 to 100 at %.

Disclosed herein is a method for regenerating retinal tissue which includes preparing a luminescent scaffold, implanting the luminescent scaffold in a portion of retina, for example subretinal area, emitting a green light from the luminescent nanoparticles in a luminescence phenomenon, and absorbing the emitted light by retinal cells for regenerating retinal tissue by stimulating the retinal cells. Moreover, preparing a luminescent scaffold may comprise synthesizing a plurality of luminescent particles, dispersing the luminescent particles in a polymeric matrix to form a luminescent composite, and electrospinning the luminescent composite to form the luminescent scaffold.

Provided are a nanophosphor and a silica composite including the nanophosphor. The nanophosphor has a core/first shell/second shell structure or a core/first shell/second shell/third shell structure, wherein the core includes a Yb.sup.3+-doped fluoride-based nanoparticle, the first shell is an up-conversion shell including a Yb.sup.3+ and Tm.sup.3+-codoped fluoride-based crystalline composition, the second shell is a fluoride-based emission shell, and the third shell is an outermost crystalline shell.

A wavelength converting module and a semiconductor light-emitting apparatus using the wavelength converting module can emit various color lights. The light-emitting apparatus can include a semiconductor light source emitting an exciting light and an optical reflector, which reflects the exciting light toward the wavelength converting module. The wavelength converting module can include a base board and a cavity formed by a divider located on the base board. The exciting light can enter into the cavity including a phosphor layer contained in the wavelength converting module and can emit a mixture light using the phosphor layer in only one cavity. Thus, the semiconductor light-emitting apparatus using the wavelength converting module can emit various color lights having a high light-intensity and a substantially uniform color tone in order to be able to be used for vehicle lamp such as a headlight, general lighting, a stage light, a street light, a projector, etc.

Disclosed is a novel composition of matter that provides highly efficient energy conversion from NIR to NIR wavelengths, with either up-, down-, or both up- and down-converting transitions. Disclosed is a composition having the molecular formula NaYF.sub.4:Yb.sub.xTm.sub.yNd.sub.z, where 0x0.98, 0y0.02, and 0z0.06. Also disclosed is a core-shell structure, wherein the core is a composition having the molecular formula NaYF.sub.4:Yb.sub.xTm.sub.yNd.sub.z, where 0x0.98, 0y0.02, and 0z0.06, and the shell is composition having the molecular formula NaYF.sub.4:Nd.sub.w, where 0w0.1.

Compositions of matter, downconversion layers including the compositions of matter, and devices including the compositions of matter are described. In an embodiment, the compositions of matter are downconversion materials configured to absorb a quantum of energy of a first energy and, in response, emit two or more quanta of energy of a second energy less than the first energy. Methods of making and depositing downconversion materials are also described. Downconversion precursor mixtures suitable for making downconversion materials and methods of making the same are also described.