Lanzhou University Wang Deyin@Wang Yuhua LPR replaced the Al3+-Al3+ pairs in BaLu2Al4SiO12: Ce3+ with Mg2+-Si4+ pairs to prepare a new blue-light-excitable yellow-emitting phosphor BaLu2(Mg0.6Al2.8Si1.6)O12: Ce3+, with an external quantum efficiency (EQE) of 66.2%. While Ce3+ emission red-shifted, this substitution also broadened Ce3+ emission and reduced its thermal stability. The change in the spectrum is due to the change in the local crystal field of Ce3+ and the change in positional symmetry caused by the Mg2+-Si4+ substitution.
In order to evaluate the feasibility of the newly developed yellow-emitting phosphor for high-power laser lighting, it was constructed as a phosphor wheel. Under the irradiation of a blue laser with a power density of 90.7 W mm2, the luminous flux of the yellow phosphor was 3894 lm, and there was no obvious emission saturation phenomenon. The yellow phosphor wheel was excited by blue laser diodes (LDs) with a power density of 25.2 W mm?2, generating bright white light with a luminance of 1718.1 lm, a correlated color temperature of 5983 K, a color rendering index of 65.0, and color coordinates of (0.3203, 0.3631).
These results indicate that the newly synthesized yellow-emitting phosphor has significant potential for high-power laser-driven lighting applications.