A Ca3Sc2Si3O12:Ce3+,Cr3+,Li+ phosphor-in-glass film for high-power laser-driven near-infrared lighting

Abstract

Advanced laser-driven near-infrared (NIR) lighting demonstrates the evolution of invisible lighting/imaging technology towards long distances, high brightness and high resolution. In response to the shortage of laser-driven NIR phosphor color converters with desirable properties, herein, we designed and fabricated a Ca₃Sc₂Si₃O₁₂:Ce³⁺,Cr³⁺,Li⁺ phosphor-in-glass film (PiGF) composite, which succeeded in realizing a blue-laser converted NIR optical output of 1.697 W. Elaborate experiments were carried out to optimize the preparation conditions and sample parameters. Microstructural and spectroscopic studies demonstrate an insignificant interfacial reaction during sintering and thus the retained luminescence performance of NIR phosphor powders. Upon laser-driven lighting, the luminescence saturation behavior was carefully examined in different excitation modes to gain insight into the saturation mechanism. It was found that Ce³⁺ ions become more susceptible to heat and Cr³⁺ ions suffer more from the incident high-density blue photons; correspondingly, thermal quenching/intensity quenching accounting for Ce³⁺ is 71%/29% and for Cr³⁺ is 26%/74% when luminescence saturation occurs. The demonstration experiment shows a better imaging effect and deeper penetration capability of the fabricated high-power laser-driven NIR illumination source than the conventional NIR LED, revealing its potential application in night vision and non-destructive analysis and identification.