Inch-sized aligned polymer nanofiber films with embedded CH₃NH₃PbBr₃ nanocrystals: Electrospinning fabrication using a folded aluminum foil as the collector

Perovskite nanocrystal embedded polymer nanofibers with polarized emissions are interesting materials for down-shifting applications. By using a folded aluminum foil as a collector, we fabricated inch-size aligned polymer nanofiber films with embedded CH₃NH₃PbBr₃ nanocrystals by adapting an electrospinning technique. It was found that the addition of an appropriate amount of cyanoethyl cellulose (CEC) makes the dispersion of MAPbBr₃ in the nanofibers more uniform. Using a precursor solution with MAPbBr₃ of 10% and CEC of 1 wt%, the resulting nanofiber films show strong polarized emission with quantum yields up to 51%. The emission dichroic ratio and emission polarization ratio can reach 5.21 and 0.43, respectively. These polarized emissive films can be potentially applied as down converters for liquid crystal display backlights and other polarization selective photonic devices.