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.