In situ synthesis of coaxial CsPbX3@polymer (X = Cl, Br, I) fibers with significantly enhanced water stability

Abstract

Inorganic perovskites (IP) CsPbX₃ (X = Cl, Br, I) have rapidly emerged as excellent candidate materials for optoelectronic devices due to their superior optical/electronic performances. However, poor stability related to their intrinsic ionic character significantly limits their practical applications. Here, a coaxial electrospinning strategy was reported for in situ growth of IP nanocrystals (NCs) in polymer fibers with core/shell structure. The said strategy was based on one-step electrospinning of core solutions containing IP precursors and polymers while the shell solutions containing polymers only contributed to the coaxial structure. The NCs moving in/out of the surface of the core were encapsulated by the shell layer. Compared with the traditional CsPbBr₃@polymer fibers without the shell layer, the obtained coaxial fibers exhibited fundamentally improved water stabilities. Their PL quantum yield (QY) retained >90% of its original value after being immersed in water for 10 days and maintained at >84% after 180 days.