Formulation of Water-Resistant Fluorescent Ink from Novel Octagonal CsPbBr<sub>3</sub>/CsPb<sub>2</sub>Br<sub>5</sub> Composite Plates Coordinated with Thermoplastic Polyurethane
Jindou Shi, Ye Tian, Wenxing Gao, Meimei Xu, Yuanting Wu, Wanyin Ge
Abstract
Exploring a convenient method to solve the stability problem of all-inorganic halide perovskite nanocrystals (NCs) has become an urgent task in their practical application. In recent years, cesium lead halide perovskite CsPbX3 (X = Cl, Br, and I) NCs, as the star material for the development of next-generation optoelectronic devices, have stimulated tremendous interest due to their excellent optical and electronic properties. Unfortunately, the performance of CsPbX3 NCs will become impaired due to interference from the external environment. Here, a convenient one-pot method was proposed, and the transition of CsPbBr3 quantum dots to two-dimensional CsPbBr3/CsPb2Br5 composite plates (CPs) was achieved by adjusting the reaction time. Large-scale octagonal CsPbBr3/CsPb2Br5 CPs were quickly obtained, and the morphology and phase transition in the entire reaction time period were explored. Subsequently, the products obtained at different reaction times were evaluated for long-term storage stability under air conditions, and the results showed that the CsPbBr3/CsPb2Br5 CPs exhibited excellent photoluminescence stability. The proposed preparation method presents a convenient way to improve the stability of CsPbX3 with low cost. On the other hand, by incorporating these products into thermoplastic polyurethane (TPU), a waterproof ink material that can be written directly was realized, where CsPbBr3/CsPb2Br5/TPU waterproof composite ink exhibits excellent stability and recyclability under aqueous solutions at different temperatures, which will provide a new choice for the commercial development of perovskite.