FLUORESCENT SUBSTANCE, METHOD FOR PRODUCTION THEREOF, AND WAVELENGTH CONVERTER, LIGHT-EMITTING DEVICE AND LIGHTING DEVICE

摘要

[PROBLEMS] To provide: a fluorescent substance having a high quantum efficiency and capable of emitting a light having a yellowish green color; a method for producing the fluorescent substance; and a wavelength converter, a light-emitting device and a lighting device each having an improved luminous efficiency. [MEANS FOR SOLVING PROBLEMS] Disclosed is a fluorescent substance comprising M¹ [wherein M¹ represents at least one member selected from Sr, Ba and Ca], Eu and Si. The fluorescent substance comprises a crystal represented by (M¹,Eu)₂SiO₄ as the main crystal, wherein the concentration of a bivalent Eu ion relative to the total amount of the bivalent Eu ion and a trivalent Eu ion is 90% or more as measured from the X-ray absorption near edge structure (XANES) spectrum of the fluorescent substance. In the fluorescent substance, the sum total of the molar ratio of M¹ per 1 mole of Si and the molar ratio of Eu per 1 mole of Si [i.e., ((M¹+Eu)/Si)] is less than 2.