Yixuan Chen

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.

Persistent luminescence nanoparticles (PLNPs) are unique optical nanomaterials that emit a long-lasting afterglow in the absence of real-time excitation, enabling biosensing with near-zero background interference. This review summarizes recent advances in PLNP-based biosensing, highlighting how persistent luminescence improves analytical sensitivity, specificity, and operational simplicity in biological environments. We first outline foundational principles for constructing PLNP biosensors, including signal transduction via (1) analyte-regulated luminescence resonance energy transfer, (2) capture and enrichment of PLNPs for time-gated readout, and (3) ratiometric persistent luminescence. We then comprehensively discuss sensing strategies across major analyte classes, including biomolecules, small molecules, ions, and physiological parameters, such as local temperature. Finally, we examine current challenges in PLNP synthesis, surface engineering, multiplexing, and biosafety, and outline future directions toward next-generation persistent luminescence biosensors with enhanced brightness, programmability, and translational potential. Together, these developments position PLNPs as powerful and increasingly versatile platforms for high-performance biosensing and bioanalysis.

Self-driving laboratories (SDLs) integrating automation and data-driven control are increasingly used in materials synthesis. Existing SDLs still face challenges in hardware integration and stable flow operation. Here, we report a modular fluidic-microwave SDL for the automated synthesis of perovskite nanocrystals (PNCs) with programmable thermal profiles and inline photoluminescence monitoring. Its constant-pressure fluidics and batch microwave design decouple reaction temperature from residence time, suppress flow pulsation, and yield reproducible low-noise data sets. Using CsPbX₃ (X = Cl, Br, I), the platform achieves relative standard deviations of 1.53% in fwhm, 0.06% in peak wavelength, and 1.85% in PL intensity across runs. Automated parameter screening identifies an optimal synthesis window (120-140 °C, 28 °C min^-1, 120-180 s, Pb/Cs = 2-3) that produces phase-pure nanocrystals with narrow emission line widths (∼18-19 nm). This SDL provides a reproducible, programmable basis for closed-loop optimization and AI-guided nanomaterials synthesis.