βtype sialon fluorescent substance

摘要

A &bgr; 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 &bgr; type Sialon composition represented by general formula: Si6-zAlzOzN8-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 &bgr; 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.