ACID NITRIDE PHOSPHOR POWDER AND METHOD FOR PRODUCING SAME

摘要

Provided is an acid nitride phosphor which has a fluorescence peak wavelength of 587 to 630 nm and also has higher external quantum efficiency compared with the conventional ones. The present invention relates to a method for producing an acid nitride phosphor powder containing 50 to 10000 ppm of Li, said method being characterized by comprising mixing a silicon nitride powder, a substance that serves as an aluminum source, a substance that serves as a calcium source and a substance that serves as an europium source together, firing the resultant mixture in an inert gas atmosphere or a reducing gas atmosphere at 1500 to 2000°C to produce, as an intermediate product, a fired acid nitride phosphor product containing a Ca-containing α-type SiAlON as the main component, and then further thermally treating the fired acid nitride phosphor product under conditions in which Li is present in an inert gas atmosphere or a reducing gas atmosphere at a temperature of 1450°C or higher and lower than the firing temperature.