Facile Uniaxial Electrospinning Strategy To Embed CsPbBr₃ Nanocrystals with Enhanced Water/Thermal Stabilities for Reversible Fluorescence Switches

Abstract

All-inorganic halide perovskite nanocrystals with their fascinating optical properties have drawn increasing attention as promising nanoemitters. However, due to the intrinsic poor colloidal stability against the external environment, the practical applications are greatly limited. Herein, a facile and effective strategy for the in situ encapsulation of CsPbBr3 NCs into highly dense multichannel polyacrylonitrile (PAN) nanofibers via a uniaxial electrospinning strategy is presented. Such a facile uniaxial electrospinning strategy enables the in situ formation of CsPbBr3 NCs in PAN nanofibers without the introduction of stabilizers. Significantly, the obtained CsPbBr3 nanofibers not only display intense fluorescence with a high quantum yield (≈48%) but also present high stability when exposed to water and air owing to the peripheral protecting matrix of PAN. After immersing CsPbBr3@PAN nanofiber films in water for 100 days, the quantum yield of CsPbBr3@PAN nanofibers maintained 87.5% of the original value, which was much higher than that using CsPbBr3 NCs. Furthermore, based on the spectral overlap between the electrochromic material of ruthenium purple and fluorescence of CsPbBr3@PAN nanofiber films with excellent water stability, a reversible fluorescence switch is constructed with good fatigue resistance, suggesting their promising applications.

Studies on the optical stability of CsPbBr3 with different dimensions (0D, 1D, 2D, 3D) under thermal environments

“…6,7 Especially, the optical stability of CsPbBr 3 under thermal environment has been most important, which mainly stemmed from the fact that optoelectronic devices inevitably generated high temperatures on the device surface during long-term energized conditions, thereby placing a high demand on the optical stability of CsPbBr 3 . 8–12 However, the soft matter structure of CsPbBr 3 enables them to exhibit a strong response to small perturbations of the external thermal environment, 13 which would be highly unfavorable to the development of perovskite optoelectronic devices; thus, it is urgent to systematically investigate the optical stability of CsPbBr 3 under thermal environments.…”