BETA-TYPE SIALON FLUORESCENT SUBSTANCE

摘要

A ² type Sialon fluorescent substance is disclosed that is capable of achieving enhanced brightness of a white light emitting diode using blue to ultraviolet light as a light source. In the fluorescent substance which contains not less than 90 % by mass of a ² type Sialon composition represented by general formula: Si 6-z Al z O z N 8-z as a host material wherein z is not less than 0.24 and not more than 0.42, Eu is present dissolved in solid solution as a luminescent center at a content of 0.05 to 0.2 % by atom. The ² type Sialon fluorescent substance is preferably in the form of a powder having an average particle size of not less than 1 µm and not more than 20 µm. A white LED of good luminescent characteristics can be obtained by using a blue or ultraviolet light emitting diode as a excitation light source in combination with a fluorescent substance that emits yellow or red light.