Fluorescent substance, process for production of fluorescent substance, light-emitting device and light-emitting module

A process for production of a fluorescent substance which emits luminescence having a peak in the wavelength range of 570 to 650 nm under excitation by light in the wavelength range of 250 to 500 nm, the process comprising:

• mixing
• a compound containing a metal element M1 selected from the group consisting of tetravalent metal elements,
• a compound containing a metal element M2 selected from the group consisting of trivalent metal elements other than In(III) and Ga(III),
• a compound containing a metal element M selected from the group consisting of metal elements, with the proviso that M is not M1, M2, In(III) and Ga(III),
• a compound containing an emission center element EC, with the proviso that EC is not M, M1, M2, In(III) and Ga(III), and
• a compound containing a metal element L selected from the group consisting of an oxide or nitride of In(III) and an oxide or nitride of Ga(III),
• to prepare a material mixture;
• and
• firing the material mixture to produce the fluorescent substance;
• wherein
• the fluorescent substance is of formula (I):
• (M1-xECx)aM1bM2LcOdNe (I)
• wherein
• 0<x<0.4, 0.65<a<0.80, 2<b<3, 0<c<0.1, 0.3<d<0.6 and 4<e<5.