Color stable red-emitting phosphors

A lighting apparatus comprising a semiconductor light source;

• and
• a color stable Mn4+ doped phosphor of formula K2SiF6:Mn4+, wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 8 hours is ≤4%.

A backlight device comprising a semiconductor light source;

• and
• a color stable Mn4+ doped phosphor of formula K2SiF6:Mn4+, wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 8 hours is ≤4%.

A color stable Mn4+ doped phosphor of formula K2SiF6:Mn4+, wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 8 hours is ≤4%.