FLUORESCENT SUBSTANCE AND PROCESS FOR PRODUCING THE SAME, AND LIGHT EMITTING DEVICE USING SAID FLUORESCENT SUBSTANCE

摘要

This invention provides a fluorescent substance that has a broad peak of a luminescence spectrum in a green to yellow range, has such a wide and flat excitation band that can realize the use of a wide range of light from near ultraviolet/ultraviolet light to blue light as excitation light, and excellent luminescence efficiency and luminance. The fluorescent substance is represented by general formula MmAaBbOoNn:Z wherein M represents one or more elements which take a valence of II; A represents one or more elements which take a valence of III; B represents one or more elements which take a valence of IV; O represents oxygen; N represents nitrogen; Z represents one or more activators; and 4.0 < (a + b)/m < 7.0, a/m = 0.5, b/a > 2.5, n > o, and n = 2/3m + a + 4/3b - 2/3o. Upon excitation with light in a wavelength range of 300 nm to 500 nm, the fluorescent substance exhibits a luminescence spectrum having a peak wavelength range of 500 nm to 650 nm.