Integrated NIR-II light sources via Cr4+-doped wafer-scale composite ceramics for enhanced image sensing

Near-infrared-II (NIR-II) photons hold great potential in assisting non-invasive imaging and optical signal sensing. However, the integration of broadband NIR-II light sources with photodetectors to improve the imaging sensitivity and spatial resolution is highly demanded. Herein, we have developed MgO-Li 2 SrGeO 4 :Cr 4+ composite ceramics, which demonstrate a broad NIR-II emission band centered at 1160 nm originating from spin-allowed 3 T 2 → 3 A 2 ( 3 F) transition of Cr 4+ . The incorporated nano-MgO particles serve as light-guiding channels while filling the pores and prevents the reduction of Cr 4+ , enhancing the external quantum efficiency and thermal conductivity of the composite ceramics to 53% and 17.8 W·m –1 ·K –1 , respectively. The dynamic wafer-scale luminescent ceramic wheel delivers a record broadband NIR-II emission output power of 1.9 W under 20 W·mm -2 red laser excitation, which facilitates imaging sensing of commercial PbS photodetectors by enhancing their photocurrents and signal-to-noise ratios. These results establish the feasibility of high-power broadband NIR-II light sources integrated with photodetectors, and further demonstrate the combination of intelligent algorithms toward high-resolution optical imaging.