Abstract: A light emitting phosphor material for an alternating current thin-film electroluminescent device that includes the phosphor material sandwiched between a pair of dielectric layers. The phosphor material comprises a first layer having a thickness greater than 600 nanometers wherein the first phosphor material has a luminance output at 25 degrees C. and a decreased luminance output at 50 degrees C. greater than 20 percent of the luminance output at 25 degrees C. The phosphor material comprises a second phosphor layer overlaying the first phosphor layer having a thickness less than 400 nanometers wherein the decreased luminance output at 50 degrees C. is less than 20 percent with the second phosphor layer.