Large‐Scale, Stretchable, Self‐Protective, and Multifunctional Perovskite Luminescent Filament with Ultra‐High Stability

Abstract

Lead halide perovskites possess great application potential in flexible displays and wearable optoelectronics owing to their prominent optoelectronic properties. However, the intrinsic instability upon moisture, heat, and ultraviolet light irradiation hinders their development and application. In this work, an ultra‐stable CsPbX3 (X = Cl, Br, I) perovskite luminescent filament (PLF) with high stretchability (∼2400%) and luminescence is introduced by a facile environmental‐friendly wet‐spinning technology via solvent extraction (with a high production rate of 0.7 m/min and low cost of 1.56 USD per 100 m). The CsPbX3 PLF displays homogeneous luminescence (photoluminescence quantum yield of 24.5%), tunable emission spectrum, and high color purity. Benefiting from the in‐situ encapsulation effect of the hydrophobic thermoplastic polyurethane (TPU) and the chelation of the Lewis base C = O in TPU with the Lewis acid Pb2+, the CsPbBr3 PLF demonstrates ultra‐high photoluminescence (PL) stability when stored in ambient air and high humidity circumstance, annealed at 50 °C, and dipped in water for 30 d, illuminated under ultraviolet light for 300 min, and immersed in organic solvents and solutions with pH of 1–13 for 5 min, respectively. Impressively, it retains 80% of its initial PL after being recycled 5 times. Overall, the CsPbX3 PLF demonstrates promising prospects in multifunctional applications, including organic dyes and tensile strain sensing, flexible pattern displays, secondary anti‐counterfeiting, and hazard warning systems.This article is protected by copyright. All rights reserved

Stable, Scalable, and Free-Standing Perovskite Quantum Dots Composite Reinforced by Cellulose Fibers

“…Although the flexibility of the composite can be improved by fabricating thin films, the brittleness of commonly used rigid and brittle inorganic encapsulation materials restricts the application of these materials in flexible devices. To this end, enormous effort has been devoted to developing polymer composites for lightweight flexible devices. − The fabrication process of perovskite QD/polymer composites is usually a complicated and time-consuming multistep process. Long-chain ligands, such as oleic acid (OA) and oleylamine (OLA), are necessary to stabilize quantum dot composites, whether in colloids or in polymer composites.…”

“…This increases the complexity and cost of raw materials. − In addition to the commonly used OA and OLA, amino acids, hydroxyl groups, and polymers with functional groups were also used to stabilize perovskite QDs. − ,− Besides the conventional PQD/polymer composite thin film, PQD/polymer composite nanofibers fabricated by spinning methods have gained increasing attention. The PQDs can be encapsulated by the polymer matrix or shell formed in the electrospinning or wet spinning process, and the composite nanofibers can be fabricated into flexible luminescent textiles by knitting or weaving, resulting in high performance and stability for flexible luminescent application. ,− However, these spinning methods require complicated equipment and an additional knitting or weaving process. Moreover, the process and equipment required for uniform large-scale perovskite/polymer flexible composite films for scalable manufacturing are far more complex than those for small-scale polymer composite films.…”