Facile Synthesis of Stable Yb3+-Doped Perovskite Nanocrystals in Mesoporous Silica for Near-Infrared Emission.

Yb3+-doped lead halide perovskites are promising near-infrared (NIR) emitters, but their practical implementation is often limited by poor environmental stability, defect-induced nonradiative loss, and difficulties in achieving reproducible doping and device integration. Herein, we report a mesoporous silica nanoreactor (MSN) strategy for the controlled synthesis of CsPbCl3:Yb-MSN nanocomposites with efficient 980 nm emission. The confined growth environment provided by the mesoporous silica matrix enables regulated crystallization of Yb3+-doped perovskite nanocrystals while reducing surface exposure and improving resistance to environmental degradation. As a result, the obtained CsPbCl3:Yb-MSN nanocomposites exhibit enhanced structural robustness, superior optical stability, and an absolute photoluminescence quantum yield of 146%, indicating efficient Yb3+-activated near-infrared emission. To demonstrate practical applicability, the as-prepared nanocomposite was integrated into a single-chip NIR LED using a UV excitation chip. The resulting device shows stable down-converted NIR output, and after optical filtering, the emission is centered at 980 nm with a relatively narrow full width at half-maximum (fwhm) of 35 nm. Imaging experiments further confirmed the practical utility of the device. The packaged NIR LED enables clear object visualization, while leaf transillumination demonstrates its capability for active NIR transmission imaging with improved visualization of internal tissue structures. This work establishes a practical route from stable Yb-doped perovskite nanomaterials to compact NIR devices and highlights their potential in portable sensing and related optical applications.