Synergistic Chlorine Source Regulation and Defect-Passivation Strategy for Stable Blue-Emitting Perovskite Films Toward Non-Invasive Jaundice Therapy

Lead halide perovskites are promising next-generation optoelectronic materials due to their solution processability, tunable bandgap, and excellent photoelectric properties. However, achieving deep-blue emission in all-inorganic CsPbX3 nanocrystals remains challenging due to phase separation, halide volatilization, and insufficient stability, limiting industrial application. Herein, a collaborative strategy of chlorine source regulation, defect passivation, and fiber integration is proposed. By incorporating beta-cyclodextrin chloride (betaCD-Cl) into CsPbBr3, large-scale deep-blue CsPbBr3-xClx@betaCD-Cl microcrystals are synthesized via a mechanosynthesis route. Flexible blue-light fiber films fabricated via electrospinning show a photoluminescence quantum yield of 55.79% and excellent environmental stability. The films also enable near-infrared-to-blue photon upconversion, achieving efficient bilirubin degradation and showing promise for next-generation non-invasive phototherapeutic blankets.