FLUORESCENT SUBSTANCE, METHOD OF PRODUCING THE SAME AND LIGHT-EMITTING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a red-light-emitting fluorescent substance with high luminous efficiency and its production method.SOLUTION: A red-light-emitting fluorescent substance is based on potassium silicofluoride and has a basic composition of the surface of formula (A): KaSiFb. The fluorescent substance is activated by manganese, and the amount of manganese present in the surface of the fluorescent substance is 0.2 mol% or less relative to the total amount of all the elements present in the surface of the fluorescent substance. The fluorescent substance can be produced by bringing a reaction solution containing potassium permanganate into contact with an Si source and washing the resultant product with a weak acid.