Nanoscale optical imaging of perovskite nanocrystals directly embedded in polymer fiber

Abstract

A polymer fiber film embedded with light-emitting inorganic perovskite nanocrystals (IPNCs) was prepared by multi-nozzle electrospinning of the solutions containing the inorganic perovskite (IP) precursors (CsX and PbX2) and polystyrene (PS). This is a simple and versatile method for direct confinement of nano-sized functional materials inside continuous fibers. The PL emission color of the hybrid fibers can be modulated using combinations of red (R), green (G), and blue (B) precursor solutions in one-step multi-nozzle electrospinning, leading to seven colors: R, G, B, cyan, yellow, magenta, and white. Intriguingly, nanoscale optical spectral imaging of fibers revealed the existence of local emission centers with different emission wavelengths in R and B emission fibers due to rapid formation of IPNCs with mixed halogen contents. These PL imaging results provide a fundamental understanding of the optical properties of the directly formed IPNCs in the polymer matrix.