Tailoring of White Luminescence in a NaLi 3 SiO 4 :Eu 2+ Phosphor Containing Broad‐Band Defect‐Induced Charge‐Transfer Emission

Abstract Single‐component materials with white‐light emission are ideal for lighting applications. However, it is very challenging to achieve white luminescence in single‐dopant activated solid phosphors. Herein, white NaLi 3 Si 1− x O 4 :Eu 2+ materials are designed via defect engineering and synthesized by reducing the Si content (0.15 ≤ x ≤ 0.25). Stochiometric NaLi 3 SiO 4 :Eu 2+ exhibits a narrow‐band blue emission at 469 nm, ascribed to the 5d → 4f transition of Eu 2+ at highly symmetric cuboid Na sites, while samples with Si content reduced by 15–25% display white emission with two peaks at 472 nm and 585 nm. The newly appeared broadband yellow peak arises from charge‐transfer transitions involving Eu 2+ and nearby defects, as verified by an unusual bandwidth, a large Stokes shift, and a long decay time. A single‐component white light‐emitting diode device is fabricated by employing a white phosphor to demonstrate a color‐rendering index of 82.9. This result provides a new design strategy for single‐component white‐light materials with broad‐band defect‐induced charge‐transfer emission.