Cs3Cu2X5纳米晶光致发光性能及光照抗菌性能OA

Lead-based halide perovskite nanocrystals have attracted extensive attention due to their outstanding optoelectronic properties.However,their small Stokes shifts often lead to severe self-absorption,which greatly limit their luminescence efficiency and practical applications.Moreover,the inherent biological toxicity of lead poses irreversible risks to human health and the environment.To address these issues,this study synthesized lead-free Cs3Cu2X5(X=Cl,Br,I)perovskite nanocrystals using a hot-injection method and systematically characterized their phase purity,compositions,and microstructures.Optical measurements,including fluorescence spectroscopy and temperature-dependent fluorescence lifetimes,revealed that the high photoluminescence quantum yield and large Stokes shifts of Cs3 Cu2 X5 nanocrystals originate from their self-trapped exciton emission mechanism.To enhance their applicability,we further coated the nanocrystals with a SiO2 shell,which significantly improved their dispersibility in aqueous media and their biocompatibility.Finally,using Escherichia coli as a model bacterium,the photo-induced antibacterial performance of the Cs3Cu2X5@SiO2 core-shell nanocrystals was evaluated through turbidity analysis and colony counting assays.This study revealed the physical origin of the outstanding luminescent properties of Cs3Cu2X5 nanocrystals and demonstrated their potential as efficient and safe optical materials in biomedical applications.