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 100? 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%.

Disclosed are a preparation method for manganese-doped red phosphor, a device and a backlight module including the product. The method includes: 1) mixing A.sub.2BF.sub.6 polycrystalline particles with mill balls; 2) mixing A.sub.2BF.sub.6 powder obtained after ball-milling with a hydrofluoric acid for secondary crystallization; 3) filtering out solid particles in A.sub.2BF.sub.6 and hydrofluoric acid solution after the secondary crystallization; 4) performing ion exchange between A.sub.2BF.sub.6 particles and A.sub.2BF.sub.6; and 5) filtering out solid particles to obtain a filter cake, and performing drying treatment to obtain manganese-doped red phosphor.

A wavelength-converting film and a light emitting device and a display device using the same are disclosed. The wavelength converting film comprises a fluoride phosphor powder with a Mn.sup.4+ as an activator, wherein the fluoride phosphor powder with the Mn.sup.4+ as the activator comprises a sheet-like crystal and has a chemical formula of A.sub.2[MF.sub.6]:Mn.sup.4+, wherein A is Li, Na, K, Rb, Cs, NH.sub.4, or a combination thereof, and M is Ge, Si, Sn, Ti, Zr, or a combination thereof.

An embodiment of an LED lamp that generates light of a color temperature that decreases with decreasing power applied to the LED lamp may include at least one lighting arrangement that may include a first LED array of serially connected first LED chips, a second LED array of serially connected second LED chips; a first photoluminescence layer covering the first LED array for generating light of a first color temperature; a second photoluminescence layer covering the second LED array for generating light of a second different color temperature; and a linear resistor serially connected to the first LED array, wherein the first LED array and second LED array are connected in parallel.

The present invention relates to a method for producing a hexafluoromanganate(IV), said method being characterized by comprising: inserting an anode and a cathode into a reaction solution that contains a compound containing manganese having an atomic valence of less than 4 and/or manganese having an atomic valence of more than 4 and hydrogen fluoride; and then applying an electric current having an electric current density of 100 to 1000 A/m.sup.2 between the anode and the cathode. According to the present invention, it becomes possible to produce a hexafluoromanganate(IV) in which the content ratio of manganese having an atomic valence of 4 is high and the contamination with oxygen is reduced and which has high purity. When a complex fluoride red phosphor is produced using the hexafluoromanganate(IV) as a raw material, the phosphor produced has high luminescence properties, particularly high internal quantum efficiency.

Provided is a method for producing a phosphor having a chemical composition represented by formula (I), A.sub.2MF.sub.6:Mn (I) (A is one type or more of an alkali metal selected from Li, Na, K, Rb, and Cs, and includes at least Na and/or K, and M is one type or more of a tetravalent element selected from Si, Ti, Zr, Hf, Ge, and Sn.), the method comprising preparing a first hydrofluoric acid solution containing M and a second hydrofluoric acid solution containing A as well as either dissolving a compound containing Mn in either the first hydrofluoric acid solution or the second hydrofluoric acid solution or preparing a separate solution in which the compound containing Mn is dissolved. When the solutions are mixed to precipitate the phosphor of the formula (I), the solutions are mixed so that the concentration of M is 0.1 to 0.5 mol/liter when all the solutions are mixed. According to the present invention, a complex fluoride phosphor having excellent luminescence properties can be produced stably with high yield.

A coated phosphor comprises phosphor particles, wherein said phosphor particles comprise manganese-activated complex fluoride phosphors; and a coating on individual ones of said phosphor particles, said coating comprising a layer of carboxylic acid material encapsulating the individual phosphor particles.

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.

The present disclosure relates to the field of inorganic non-metallic optoelectronic functional materials, and discloses wet-resistant fluoride red phosphor and preparation and application thereof, and a white light LED device. The fluoride red phosphor is a core-shell structure: the core is Mn.sup.4+ doped fluoride red phosphor, and the chemical structural formula is A.sub.2B.sub.1-xF.sub.6:xMn.sup.4+, herein A is at least one of Li, Na, K, Rb, and Cs, B is at least one of Ti, Si, Ge, Zr, and Sn, and 0?x?0.4; and the shell is a cubic perovskite-type compound, and the chemical structural formula is CMgF.sub.3, herein C is at least one of Li, Na, K, Rb, and Cs. The present disclosure uses CMgF.sub.3 generated as a coating waterproof layer, to form the A.sub.2B.sub.1-xF.sub.6:xMn.sup.4+ core-shell structure of which the surface is coated by CMgF.sub.3, and a wet-resistant problem of the fluoride red phosphor is overcome.

An LED-filament includes first and second connectors for receiving a variable power; an at least partially light-transmissive substrate; a first LED array of serially connected first LED chips on a front face of the substrate; a second LED array of serially connected second LED chips on the front face of the substrate; a first photoluminescence layer covering the first LED array for generating a first color temperature; a second photoluminescence layer covering the second LED array for generating a second different color temperature; and at least one resistor serially connected to one of the first LED chips, where the first LED array and second LED array are connected in parallel to the first and second connectors, and where current flowing through the first LED and second LED arrays depends on the power applied to the first and second connectors and where the final color temperature of light generated by the LED-filament depends on the power applied to the first and second connectors.