Complex fluoride phosphor and method for producing same

A method for producing a complex fluoride phosphor having a chemical composition of the formula (I):

• A2MF6:Mn (I)
• wherein A is one or more alkali metal selected from the group consisting of lithium, sodium, potassium, rubidium and cesium, and includes at least sodium and/or potassium, and M is one or more tetravalent element selected from the group consisting of silicon, titanium, zirconium, hafnium, germanium and tin, the method comprising the steps of:
• providing a first hydrofluoric acid solution which contains M and a second hydrofluoric acid solution which contains A,
• dissolving a manganese-containing compound in either of the first hydrofluoric acid solution and the second hydrofluoric acid solution or separately preparing a solution in which a manganese-containing compound is dissolved, and
• mixing together the solutions so as to precipitate the phosphor of formula (I) such that the concentration of M, when the solutions are completely mixed, is at least 0.1 mol/L and not more than 0.5 mol/L, wherein the amount of A when the solutions are completely mixed, expressed as a molar ratio with respect to the sum of M and manganese, is at least 2.8.