FAPbBr Perovskite Nanocrystals Embedded in Poly(L-lactic acid) Nanofibrous Membranes for Enhanced Air and Water Stability.

Formamidinium lead bromide (FAPbBr) nanocrystals have emerged as a powerful platform for optoelectronic applications due to their pure green photoluminescence (PL). However, their low colloidal stability under storage and operation reduces the potential use of FAPbBr perovskite nanocrystals (PeNCs) in various applications. In this study, we prepared the poly(L-lactic acid) (PLLA) nanofibrous membrane embedded with FAPbBr perovskite nanocrystals by electrospinning the perovskite and PLLA precursor solution. This is a simple and low-cost technique for the direct confinement of nano-sized functional materials in the continuous polymer nanofibres. PLLA as a polymer matrix provided a high surface framework to fully encapsulate the perovskite NCs. In addition, we found that FAPbBr PeNCs crystallize spontaneously inside the PLLA nanofibre. The resultant PLLA-FAPbBr nanofibrous membranes were stable and remained in the water for about 45 days without any evident decomposition. The results of this research support the idea of new possibilities for the production of air-stable FAPbBr PeNCs by forming a composite with PLLA polymer. The authors believe this study is a new milestone in the development of highly stable metal halide perovskite-based nanofibres, which allow for potential use in lasers, waveguides, and flexible energy harvesters.