A lighting apparatus includes an LED light source radiationally coupled to a composite material including a phosphor of formula I and a thermally conductive material dispersed in at least a portion of a binder material. The thermally conductive material includes a material selected from the group consisting of indium oxide, tin oxide, indium tin oxide, calcium oxide, barium oxide, strontium oxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, strontium hydroxide, zinc hydroxide, aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, strontium phosphate, diamond, graphene, polyethylene nanofibers, carbon nanotubes, silver metal nanoparticles, copper metal nanoparticles, gold metal nanoparticles, aluminum metal nanoparticles, boron nitride, silicon nitride, an alkali metal halide, calcium fluoride, magnesium fluoride, a compound of formula II, and combinations thereof.