In Situ Synthesis of Robust Polyvinylpyrrolidone-Based Perovskite Nanocrystal Powders by the Fiber-Spinning Chemistry Method and Their Versatile 3D Printing Patterns

All-inorganic halide perovskite nanocrystals (PNCs) have received increasing attention due to their excellent optical properties. However, the inherent instability and the large amount of volatile organic compounds during the production process have severely limited their applications. In this research, we employed the microfluidic electrostatic spinning method to synthesize polyvinylpyrrolidone (PVP)-based PNC (CsPbBr3/PVP) powders directly by spinning chemistry, where the fibers serve as reactors. Thus, 20.1 g of CsPbBr3/PVP powders was obtained, which exhibits good fluorescent properties and high stability. Based on these excellent properties, several new applications were explored, including 3D printing, direct encapsulants for light-emitting diodes, and fluorescent coatings. It should be noted that the powder showed distinct advantages in 3D printing, allowing the fabrication of a series of fluorescent patterns, which offers a new candidate for fluorescent 3D printable materials. This work not only opens up an optimal way for facile production of fluorescent powders by the spinning chemistry strategy, but also provides a new perspective for various application directions, especially for 3D printing.