Metal halide perovskite nanocrystals with enhanced photoluminescence and stability toward anti-counterfeiting high-performance flexible fibers

As a new type of light-collecting and luminescent material, all-inorganic cesium lead halide CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) are expected to have a wide range of applications in the fields of photovoltaics, optoelectronics, and fluorescence anti-counterfeiting, etc. Therefore, improving the fluorescence performance and stability of CsPbX3 perovskite NCs to prompt their applications would promise both fundamental and practical significance for in-depth research in the field of halide perovskites. In this paper, we developed a modification strategy to introduce a halogen source, zinc bromide (ZnBr2) in hexane, to CsPbX3 perovskite that can be conducted under atmospheric conditions with reduced reaction cost and easier operation. The first work in this paper was to apply the modification strategy to CsPbI3 nanowires (NWs). Compared with the untreated NWs, the ZnBr2/hexane modified CsPbI3 NWs exhibited better fluorescence properties. Subsequently, based on the study of perovskite NWs, we investigated perovskite nanocrystal-CsPbI3 nanorods (NRs) with different morphologies and sizes. It was found that the luminescence properties of nanorods (NRs) were superior. Later, we infiltrated the modified NRs into the aramid/polyphenylene sulfide (ACFs/PPS) composite paper yielded from our previous work to study its fluorescence performance for anti-counterfeiting. Their luminescence properties under ultraviolet light irradiation enable better performance in fluorescence anti-counterfeiting. The ZnBr2/hexane modification strategy and the applications studied in this work will expand the scope of perovskite research, laying the foundation for the applications of fluorescent anti-counterfeiting, nano-photoelectric devices, and fluorescent composite materials.