A light emitting device includes a light emitting element adapted to emit blue light, quantum dots that absorb part of the blue light emitted from the light emitting element to emit green light, and at least one of a KSF phosphor adapted to absorb part of the blue light emitted from the light emitting element to emit red light and a MGF phosphor adapted to absorb part of the blue light emitted from the light emitting element to emit red light.

A vehicle applique is provided that includes a substantially transparent substrate defining first and second surfaces, a decorative film positioned on the first surface of the substrate, and an over-mold positioned over the film. The over-mold defines at least one diffraction grating and a light source is positioned proximate the second surface of the substrate. The light source is configured to emit light through the substrate and the over-mold.

A luminescent substance particle including BaSnO.sub.3 having a perovskite-type structure, wherein the luminescent substance particle contains one of 0.07% by mass or less of Fe (iron), 0.005% by mass or less of Cr (chromium) and 0.02% by mass or less of Ni (nickel). A wavelength conversion film including the luminescent substance particle for converting a light in an ultraviolet region to a light in an infrared region. A wavelength conversion device including a substrate and the wavelength conversion film formed on the substrate.

The present invention provides photoluminescent iron-doped barium stannate materials absorbing ultraviolet (UV) light and exhibiting strong near-infrared (NIR) luminescence. Such materials exhibit increased integrated photoluminescence intensity in comparison to known BaSnO.sub.3 and iron-doped barium stannate materials, and therefore they are particularly useful for the production of photoluminescent security ink compositions and transparent covert security features with improved anti-counterfeiting resistance that can be used for protection of documents and articles against counterfeit and illegal reproduction.

A composition includes a plurality of lead halide perovskite nanocrystals and an ammonium halide-containing copolymer or a guanidinium halide-containing copolymer. The ammonium halide-containing copolymer and guanidinium halide-containing copolymer can include repeating units defined herein. The composition can be particularly useful for color tuning perovskite nanocrystals, and can be well-suited for light emitting applications, including light emitting diodes.

A light emitting device includes a light emitting element adapted to emit blue light, quantum dots that absorb part of the blue light emitted from the light emitting element to emit green light, and at least one of a KSF phosphor adapted to absorb part of the blue light emitted from the light emitting element to emit red light and a MGF phosphor adapted to absorb part of the blue light emitted from the light emitting element to emit red light.

A composite material includes at least one photoluminescent material embedded as a light source in a transparent matrix, wherein a refractive index (n.sub.P) of the at least one photoluminescent material and a refractive index (n.sub.M) of the matrix differ by at most ±0.2.

Security of a printed matter is enhanced, and a visual image is made clear if a latent image formed by a coating printed on a matter to be printed for a security enhancement of the printed matter becomes the visual image. A security ink pigment contains a powder. A main constituent of the powder is a perovskite-type oxide. The perovskite-type oxide has a composition expressed as a general formula of ABO.sub.3. A is mainly made of Ba. B is mainly made of Sn. The powder emits an infrared fluorescence when being irradiated with an ultraviolet excitation light. The perovskite-type oxide has a crystal lattice constant having a difference equal to or smaller than 0.002 angstrom from a theoretical crystal lattice constant of the perovskite-type oxide having a composition expressed as a composition formula of BaSnO.sub.3.

A luminescent substance particle includes BaSnO.sub.3:Zn having a perovskite-type structure, a content of Zn (zinc) being more than 0.0% by mass and less than 8.0% by mass. Alternatively, a luminescent substance particle includes BaSnO.sub.3:Mg having a perovskite-type structure, a content of Mg (magnesium) being more than 0.0% by mass and less than 0.1% by mass.

Present invention provides a process for the synthesis of size and composition tunable colloidal PbMgS core and PbMgS/MS core shell quantum dots emitting in the near infrared (NIR) region of the spectrum in a single operation in a continuous flow reactor. M includes at least one of Cd, Mg, Zn and Cu metals.