| abstract |
To provide a phosphor emitting green fluorescence and having such superior characteristics as excellent conversion efficiency of blue light or near-ultraviolet light and excellent color purity,n a phosphor satisfying the following conditions (i) to (v): (i) the wavelength of emission peak thereof is 510 nm or longer and 542 nm or shorter, when excited with light of 400 nm or 455 nm (ii) the full width at half maximum of emission peak thereof is 75 nm or narrower, when excited with light of 400 nm or 455 nm, (iii) the external quantum efficiency, which is defined by the formula below, is 0.42 or larger, when excited with light of 400 nm or 455 nm, nn (external quantum efficiency)=(internal quantum efficiency)×(absorption efficiency) (iv) a part of its surface comprises substance containing oxygen, and (v) it contains a bivalent and trivalent metal element (M II element), and its molar ratio to the total bivalent elements is larger than 1% and smaller than 15%. |