An LED-filament includes a light-transmissive substrate; a first array of LED chips on a front face of the substrate; a second array of LED chips on the front face of the substrate; a first photoluminescence arrangement covering the first array of LED chips; and a second photoluminescence arrangement covering the second array of LED chips; where the first array of LED chips and the first arrangement generate light of a first color temperature and the second array of LED chips and the second arrangement generate light of a second color temperature.

A light source using a light-converting material, in particular for the conversion of collimated or focused light, which does not operate solely on the principle of geometric concentration as known from the prior art, but which reflects light away from the interface between the surface of the conversion body (1) and the surroundings due to the high refractive index of the conversion body (1), possibly by means of an applied reflective layer. The light source uses the high refractive index and high transmittance of the phosphor material as the properties necessary to direct the light in the desired direction directly by the conversion body (1) itself. The light source emits collimated or focused intense secondary light, or a homogenised mix of primary and secondary light, or it may transmit supplementary light.

A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn.sup.4+ doped phosphor, wherein the lighting apparatus has a color shift of 1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm.sup.2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25 C.

A process for preparing a population of coated phosphor particles is presented. The process includes combining particles of a phosphor of formula I: A.sub.x [MF.sub.y]:Mn.sup.4+ with a first solution including a compound of formula II: A.sub.x[MF.sub.y] to form a suspension, where A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the [MF.sub.y] ion; and y is 5, 6 or 7. The process further includes combining a second solution including a source A.sup.+ ions with the suspension.

Disclosed is a quantum dot light emitting device including a ligand-substituted quantum dot light emitting layer with a polymer having amine groups. The introduction of the ligand-substituted quantum dot light emitting layer with a polymer having amine groups changes the energy level of an electron transport layer and enables control over the charge injection properties of the device so that the flow of electrons can be controlled. In addition, the ligand substitution is effective in removing oleic acid as a stabilizer of quantum dots to prevent an increase in driving voltage caused by the introduction of the additional material, achieving markedly improved efficiency of the device. Also disclosed is a method for fabricating the quantum dot light emitting device.

A color conversion particle includes a core; and a shell that contains the core and absorbs excitation light, and emits light at the core or at an interface between the core and the shell upon receiving the irradiated excitation light. The core is composed of a chalcogenide perovskite, and the core and the shell have band alignment that induces a Stokes shift.

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 1000 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%.

The present invention provides a method for producing a zirconia particle-containing powder that enables easy production of a zirconia sintered body having both high translucency and high strength. The present invention relates to a method for producing a zirconia particle-containing powder, comprising a drying step of spray drying a slurry containing zirconia particles, wherein the zirconia particles have an average primary particle diameter of 30 nm or less, and the slurry comprises a dispersion medium containing a liquid having a surface tension at 25 C. of 50 mN/m or less. Preferably, the zirconia particles comprise 2.0 to 9.0 mol % yttria. Preferably, wherein the content of the liquid in the dispersion medium is 50 mass % or more.

Provided are a saturable absorber including at least one material selected from a group of MXenes, and a Q-switching and mode-locked pulsed laser system using the same.

Provided are a saturable absorber including at least one material selected from a group of MXenes, and a Q-switching and mode-locked pulsed laser system using the same.