Some phosphor powders can be difficult to form into ceramic compacts because they are difficult to sinter. As described herein, phosphor powders that can degrade under conventional sintering temperatures can be sintered by heating the powder at a lower temperature, such as less than 800° C., while the powder is under greater than atmospheric pressure, such as at least 0.05 GPa. Phosphor ceramic compacts prepared by this method, and light-emitting devices incorporating these phosphor ceramic compacts, are also described.

A phosphor blend is described wherein the blend consists of a red-emitting rare earth phosphor, a green-emitting rare earth phosphor, and a blue-emitting rare earth phosphor wherein the 50% size of the phosphors is between about 12 to 15 m. The phosphor blend is incorporated into a fluorescent lamp having an increased efficacy. A dual layer coating may be used to provide an additional increase in efficacy.

Provided is a rare earth phosphovanadate phosphor that is excellent in emission characteristics and preferred also from the viewpoint of industrial production, and a production method thereof. The rare earth phosphovanadate phosphor includes at least a primary particle in which a linear uneven pattern including a plurality of ridge lines parallel to each other is formed on the surface of the particle. Further, the method for producing a rare earth phosphovanadate phosphor involves generating a mixture of a rare earth phosphovanadate phosphor and an alkali metal vanadate, and removing the alkali metal vanadate.