In-situ synthesis of stable perovskite quantum dots in core-shell nanofibers via microfluidic electrospinning

Perovskite quantum dots (PQDs) possess remarkable optical properties, such as tunable photoluminescence (PL) emission spectra, narrow full width at half maximum (FWHM) and high PL quantum yield (QY), endowing the PQDs great application prospects. However, the inherent structural instability of PQDs has seriously hindered the application of PQDs in various photoelectric devices. In this work, a microfluidic electrospinning method was used to fabricate color-tunable fluorescent formamidinium lead halogen (FAPbX₃, X = Cl, Br, I) PQDs/polymer core-shell nanofiber films. The core-shell spinning nanofiber not only supplies the interspace for the in-situ formation of PQDs, but also significantly reduces the permeability of moisture and oxygen in the air, which greatly improves the stability of PQDs. After adjusting the composition of precursors, the blue-emissive polystyrene (core) and polymethyl methacrylate (shell) coated FAPbCl₃ QDs (abbreviated as PS/FAPbCl₃/PMMA, hereinafter), green-emissive PS/FAPbBr₃/PMMA and red-emissive PS/FAPbI₃/PMMA nanofiber films were fabricated with the highest PL QY of 82.3%. Moreover, the PS/FAPbBr₃/PMMA nanofiber film exhibits great PL stability under blue light irradiation, long-term storage in the air and water resistance test. Finally, the green- and red-emissive nanofiber films were directly applied as light conversion films to fabricate wide-color-gamut display with the color gamut of 125%, indicating their tremendous potentials in optoelectronic applications.