Orange-red-emitting (Sr,Ba)3SiO5:Eu2+ phosphor-in-glass film for enhanced color rendering of laser lighting

Nitride red-emitting materials exhibit severe luminance saturation and are thus not suitable for achieving enhanced color rendering in laser lighting applications. The silicate luminescent material (Sr,Ba) 3 SiO 5 :Eu 2+ displays excellent stability and can emit orange-red light when excited by blue laser light, making it a promising candidate for realizing high-performance laser lighting. In this study, (Sr,Ba) 3 SiO 5 :Eu 2+ phosphor-in-glass (PiG) films were prepared on a sapphire substrate, and the influences of preparation temperature, mass ratio of phosphor to glass frit (PtG ratio), and film thickness on the application performance of PiG film were analyzed. The (Sr,Ba) 3 SiO 5 :Eu 2+ PiG film with a PtG ratio of 1:1 and a film thickness of ∼50 μm prepared at 475 °C exhibited optimal comprehensive luminescence performance. This film exhibited a luminous saturation threshold of 5.98 W/mm 2 , a maximum luminous flux of 372.3 lm, and a luminous efficiency of 62.3 lm/W at the luminous saturation threshold. The maximum luminous flux of the (Sr,Ba) 3 SiO 5 :Eu 2+ PiG film was 77.6% higher than that of the CaAlSiN 3 :Eu 2+ nitride PiG film. Finally, through the incorporation of green-emitting YAGG:Ce 3+ phosphor into the (Sr,Ba) 3 SiO 5 :Eu 2+ PiG film, laser-driven white light with a luminous flux of 531.7 lm and a high color rendering index (CRI) of 83.4 was realized.