Abstract: The present invention provides a light emitting device comprising: a light output; a light source that produces light having a wavelengths of 530 nm or less; and a wavelength transformer located between the light source and the light output, where the wavelength transformer comprises Sr1-xCaxGa2S4: yEu2+·zGa2S3, where x is 0.0001 to 1, y is a value defining sufficient Eu2+ to provide luminescent emission, and z is 0.0001 to 0.2 based on the mole amount of SrxCa1-xGa2S4, and where the wavelength transformer effectively increases the light at the light output, the light having a wavelength between 535 nm and 560 nm.

Abstract: Provided, among other things, is a strontium calcium thiogallate phosphor doped with divalent europium, and having the following formula: Sr1-xCaxGa2S4:yEu2+.zGa2S3, where x is 0.0001 to 1, y is a value defining sufficient Eu2+ to provide luminescent emission, and z is 0.0001 to 0.2 based on the mole amount of Sr1-xCaxGa2S4:yEu2+.

Abstract: Provided among other things is a method of forming a phosphor of the formula SrGa2S4:Eu:xGa2S3??(I) wherein x is 0.0001 to 0.

Abstract: Provided among other things is a method of forming a phosphor of the formula

Abstract: Provided, among other things, is a light emitting device comprising: a light output; a light source producing light including wavelengths of 530 nm or less; and a wavelength transformer located between the light source and the light output, comprising Sr1-xCaxGa2S4:yEu2+·zGa2S3, where x is 0.0001 to 1, y is a value defining sufficient Eu2+ to provide luminescent emission, and z is 0.0001 to 0.2 based on the mole amount of SrxCa1-xGa2S4, the wavelength transformer effective to increase the light at the light output having wavelength between 535 nm and 560 nm.

Abstract: Provided, among other things, is a strontium calcium thiogallate phosphor doped with divalent europium, and having the following formula:

Abstract: A cerium-doped garnet phosphor including a second phase of an alkali metal or alkaline earth metal aluminate. The second phase imparts improved emission efficiency but without changing the wavelength of emission. These phosphors are useful to form a white light source together with a blue or ultraviolet light-emitting LED. The phosphors are applied to the LED by forming a phosphor slurry with a polymerizable material in a solution, coating the exposed surface of the LED with a predetermined amount of the slurry, and polymerizing the polymerizable material.

Abstract: A red-emitting strontium-calcium sulfide phosphor doped with europium and a halide. These phosphors are made by combining their insoluble sulfates, adding europium as an activator, firing in hydrogen sulfide to form the corresponding sulfides, adding a halide co-activator and firing in nitrogen. The resulting phosphors can be used with various electroluminescent devices to produce colored or white light.

Abstract: A red-emitting strontium-calcium sulfide phosphor doped with europium and a halide. These phosphors are made by combining their insoluble sulfates, adding europium as an activator, firing in hydrogen sulfide to form the corresponding sulfides, adding a halide co-activator and firing in nitrogen. The resulting phosphors can be used with various electroluminescent devices to produce colored or white light.

Abstract: A method of forming high efficiency emission alkali metal activated gallium sulfide phosphors by including an excess of 1-7% of gallium. A solution of a soluble gallium salt is added to a sulfate precipitate of an alkali metal sulfate and firing in hydrogen sulfide atmosphere at temperatures up to about 900° C.

Abstract: Long persistence phosphors based on strontium sulfide and activated with a divalent rare earth such as europium and a trivalent rare earth that does not change valence in a strontium sulfide host, and including oxygen and a halide, have long persistence and emit in the red-to-orange colors of the spectrum.

Abstract: A long persistence, orange-red emitting phosphor has the formula AS:EumTrnOxXy wherein A is an alkaline earth metal ion, Tr is one or more trivalent rare earth metal ions, X is a halide, m is an integer in the range 0.01 to 0.5 atomic percent, n is an integer in the range 0.3 to 0.5 atomic percent, x is an integer in the range 0.01 to 2.0 atomic percent, and y is an integer in the range 0.01 to 0.5 atomic percent. These phosphors are made by reacting an alkaline earth metal sulfate to form the corresponding sulfide, mixing with europium oxide and one or more trivalent rare earth metal oxides to dope the sulfate, mixing the doped alkaline earth metal sulfate with a hydrocarbon and powdered sulfur, heating to form the corresponding phosphor sulfide and mixing with a halide compound to form the corresponding oxyhalide sulfide phosphor. The persistence time of the phosphors can be improved by grinding the phosphor and refiring it in the presence of an ammonium halide.

Abstract: A method of forming high efficiency emission alkali metal activated gallium sulfide phosphors by including an excess of 1-7% of gallium. A solution of a soluble gallium salt is added to a sulfate precipitate of an alkali metal sulfate and firing in hydrogen sulfide atmosphere at temperatures up to about 900° C.

Abstract: Red and orange-red emitting long persistence phosphors based on strontium sulfide and activated with a divalent rare earth such as europium, can be made by heating in the presence of an ammonium halide, or a trivalent rare earth. Using ammonium halide as the flux, the red-emitting phosphor can be molded into a desired shape. Using ammonium halide and powdered alumina, the red-emitting phosphor can be made into a powder directly. Heating a rare earth activated (Eu) strontium sulfide in the presence of a trivalent rare earth salt in the presence of sulfur and a source of carbon, fine particle size red-emitting phosphor particles can be made.