Orange emissive phosphor for warm-white light-emitting diodes

Orange-emitting Sr[sub]3Al[sub]2O[sub]5Cl[sub]2:Eu[super]2+ phosphors were synthesized by a high- temperature solid-state reaction. The excitation spectrum shows a broad band from the UV region to the blue region. The emission spectrum shows strong orange emission peaking at 610 nm, attributed to the d-f transition of the Eu[super]2+ ion. By combining the Sr[sub]3Al[sub]2O[sub]5Cl[sub]2:Eu[super]2+ phosphor with 420 nm and 460 nm chips, three white light-emitting diodes (LEDs) were fabricated. The warm-white LEDs show color rendering indexes of 76, 66 and 90 with color temperatures of 2447, 3546 and 4300 K, respectively. This new phosphor exhibits the potential to act as a single host doped with Eu[super]2+ phosphor for UV or blue chip excited white LEDs.