Inorganic compositions containing a compound semiconductor as a main constituent material are used in the fields of materials of luminescence such as fluorescence and phosphorescence, long afterglow phosphorescent materials, and the like. Some of the inorganic compositions have a characteristic that they produce light by electric energy, and are used as light sources in displays and the like. However, since materials that are currently known are not capable of sufficiently converting electric energy into light and produce a color of low purity, there are problems in heat generation, power consumption, and the like. Therefore, use of the inorganic compositions in light sources and displays is difficult, or is economically unsuitable because it requires a large amount of rare-earth salts, which are expensive.
Among the inorganic compositions containing a compound semiconductor as a main constituent material, those containing iridium are known as a raw material for preparing luminescent materials that are capable of producing light efficiently (Patent Document 2). Since Patent Document 2 does not disclose an amount of iridium contained in the iridium-containing II-VI compound semiconductor disclosed in Patent Document 2, a specific iridium content is not clear, but Patent Document 2 is at least silent on dispersibility.
Especially blue phosphors are useful not only as a luminescent material for a monochromatic light but also as a luminescent material for white color.
Among phosphors containing a II-VI compound semiconductor as a main constituent material, those doped with copper (refer to, for example, Non-patent Document 1) and those doped with thulium (Tm) (refer to, for example, Non-patent Document 2) are known as blue phosphors. Phosphors containing as a main constituent material a II-VI compound semiconductor prepared under hydrothermal conditions (refer to, for example, Patent Document 1) and phosphors containing a II-VI compound semiconductor as a main constituent material and using praseodymium as a dopant (refer to Non-patent Document 3) are also known.
Further, there are luminous bodies using iridium (Patent Document 2).    Patent Document 1: JP 2005-36214 A    Patent Document 2: JP 2006-143947 A    Non-patent Document 1: Journal of Luminescence 99 (2002) 325-334    Non-patent Document 2: Journal Non-Crystalline Solids 352 (2006) 1628-1632
Non-patent Document 3: Japanese Journal of Applied Physics Vol. 44, No. 10, 2005, p 7694-7697