Highly Efficient Novel Garnet‐Structured Yellow Emitting Phosphor for High Power Laser‐Driven Lighting

Abstract A novel blue light excitable yellow emitting phosphor, BaLu 2 (Mg 0.6 Al 2.8 Si 1.6 )O 12 :Ce 3+ , with an external quantum efficiency (EQE) of 66.2%, is developed by substituting Al 3+ ‐Al 3+ pairs in BaLu 2 Al 4 SiO 12 :Ce 3+ with Mg 2+ ‐Si 4+ pairs. Alongside the redshift of Ce 3+ emission, this substitution also broadened Ce 3+ emission and reduced its thermal stability. The spectral changes are found to result from variations in the local crystal field and site symmetry of Ce 3+ due to Mg 2+ ‐Si 4+ substitution. To assess the feasibility of the newly developed yellow‐emitting phosphor for high‐power laser lighting, it is constructed into a phosphor wheel. Owing to the efficient heat dissipation via high speed rotation of phosphor wheel, the yellow phosphor exhibit a luminous flux of 3894 lm and shows no obvious emission saturation even excited by blue laser light with a power density of 90.7 W mm −2 . Exciting the yellow phosphor wheel with a blue laser diode (LDs) at a power density of 25.2 W mm −2 resulted in bright white light with a luminous of 1718.1 lm, a correlated color temperature of 5983 K, a color rendering index of 65.0, and chromatic coordinates of (0.3203, 0.3631). These results suggest that the newly synthesized yellow‐emitting phosphor holds significant potential for high‐power laser‐driven lighting applications.