Synthesis and luminescent properties of red-emitting phosphors: ZnSiF6·6H2O and ZnGeF6·6H2O doped with Mn4+

► Crystal structure of ZnGeF6·6H2O was determined. ► New phosphors ZnSiF6·6H2O and ZnGeF6·6H2O doped with manganese(IV) were synthesized. ► Luminescent properties of ZnSiF6·6H2O and ZnGeF6·6H2O doped with manganese(IV) at different concentration levels were studied. ► Temperature-dependent luminescence properties of the doped compounds were presented. ► The CIE 1931 color coordinates of both manganese(IV) doped compounds for different temperatures were presented.