Superstoichiometric Spinel Phosphor-in-Glass Films for Laser-Driven Ultrabroadband Near-Infrared Light Sources

• • Internal quantum efficiency (IQE) of ≈ 94% and full width at half maximum (FWHM) of 300 nm at λem = 850 nm: This performance matches or exceeds typical Cr3+-doped phosphor-in-glass films, enabling high-brightness NIR sources for spectroscopy and sensing with minimal thermal quenching. • • Output power exceeding 1.1 W with a light conversion efficiency of 26% under laser excitation: This exceeds the typical 15–20% efficiency of phosphor-in-silicone converters, reducing thermal load and enabling compact, high-power NIR modules for industrial and medical applications. • • Stable operation for over 15 hours under continuous laser irradiation: Demonstrates a degradation rate of <0.1% per hour, far superior to silicone-based converters that fail within minutes, ensuring long-term reliability in harsh environments. • • Superstoichiometric MgO·1.75Al2O3 spinel phosphor suppresses interfacial reactions with silicate glass during co-sintering: This addresses the critical bottleneck of luminescence degradation in PiGF converters, enabling all-inorganic packaging with negligible PL degradation compared to bare phosphor.