Thermally Stable Red-Emitting Oxide Ceramics for Laser Lighting.

Abstract

Laser-driven phosphor-converted white light sources are highly desirable for their unprecedented energy efficiency and lighting quality. However, important challenges remain due to a lack of efficient and stable red-emitting materials. Here Eu²⁺ -activated oxide-based double perovskites are explored as red emitters with thermally stable photoluminescence. Sr₃ TaO_5.5 :Eu²⁺ ceramics exhibit a red emission band peaking at 620 nm upon blue laser pumping owing to the Eu²⁺ occupation at highly ordered substitutional lattice sites. A constructed laser-driven white light wheel under an incident power density of 19.2 W mm^-2 presents a record luminous flux of 1115 lm with an excellent color rendering index of 90. This study invigorates the development of Eu²⁺ -activated oxide-based ceramics with thermally stable luminescence for laser-pumped lighting and display applications.