Modification of the green CSS:Ce3+ phosphor by ion substitution for obtaining an orange phosphor for white LEDs

Warm white light-emitting diodes (LEDs) based on blue LED chips require abundant red light emission, and the conversion of the blue light emitted by the chips to a red light is closely related to their performances. Using a single-phase phosphor with abundant red emission in combination with blue LED chips is a potential way to achieve warm white LEDs. In our experiments, to obtain an orange phosphor suitable for warm white LEDs, phosphor samples with nominal compositions of (Ca_3−3xCe_0.06Lu_3x−0.06)(Sc_2−2xMg_2x)(Si_3−xAl_x)O₁₂ (x = 0.2−1.0) were synthesized by conventional solid-state reaction. With increasing the value of x in the nominal composition, the emission spectrum of the samples under blue light (450 nm) excitation is gradually red-shifted, and the corresponding emission color gradually changes from green to orange. White LEDs were fabricated by combining the prepared orange phosphor sample (x = 1.0) with blue InGaN LED chips. The measured luminescence performances of white LEDs demonstrate the potential of this orange phosphor for use in warm white LEDs.