In situ fabrication of halide perovskite nanocrystals embedded in polymer composites via microfluidic spinning microreactors

All-inorganic halide perovskite nanocrystals (PNCs) have gained extensive attention for their high fluorescence properties and narrow full-width-at-half maximum (FWHM). However, the low fluorescence stability, poor processability, and production of lead-containing waste solutions restrict their practical application. Here, we report a facile, effluent-free approach to prepare CsPbBr PNCs/poly(methyl)methacrylate (PMMA) composites with good photoluminescence (PL) and PL stability at room temperature, which is applicable for scale-up fabrication of fluorescent perovskite nanocrystals in a green way. A microfluidic spinning technique was employed to build 1D-2D microreactors for continuous production of CsPbBr/PMMA nanocomposites. The resultant PNC/PMMA fibers show widely tunable emission between 450 and 625 nm, a narrow FWHM of 18-42 nm, high color purity, and good processability. Then, the CsPbBr/PMMA nanocomposites were used as color converters to fabricate a liquid crystal display (LCD) backlight with a 105% wide color gamut, as well as a white light-emitting diode (WLED) with a rendering index (CRI) up to 89.2. This strategy opens a promising green avenue to mass production of fluorescent perovskite nanocrystal composite materials useful for various optoelectronic applications.