Trivalent europium is a well-known phosphorescent probe widely used in lighting devices and displays,bioassay markers,and anti-counterfeiting phosphors.Double halide perovskite nanocrystals(DHP NCs)have emerged in rec...Trivalent europium is a well-known phosphorescent probe widely used in lighting devices and displays,bioassay markers,and anti-counterfeiting phosphors.Double halide perovskite nanocrystals(DHP NCs)have emerged in recent years as attractive host lattices for various luminescent lanthanide dopants owing to the diverse range of trivalent substitutional sites.However,the effect of the DHP NC composition on the Eu^(3+)emission properties has not been systematically investigated.In this work,we prepared a series of DHP NCs containing Eu^(3+)by employing a modified colloidal hot injection procedure.The nanocrystals exhibit finely tunable Eu^(3+)5D0-^(7)F_(J)emission peaks,owing to the different dependence of the electric and magnetic dipole f-f transitions on the coordination symmetry of Eu^(3+).A variation in the values of the Eu^(3+)asymmetry factor,defined as^(7)F_(2)/^(7)F_(1)peak intensity ratio,between 1.0 and 2.5 was observed for different NC compositions,compared to ca.5 for Eu^(3+)in an aqueous solution.The asymmetry factor was also found to be dependent on the Eu^(3+)doping concentration for a given DHP NC host lattice.The sensitivity of the relative intensities of Eu^(3+)emission peaks on the DHP NC composition,together with the dual emission of these NCs,is promising for various anti-counterfeiting applications.展开更多
基金financially supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)(Nos.RGPIN-2020-04958 and STPGP 521224-2018)Scholars at Risk(SAR)Network for a research fellowship(SAR-Ukraine Fellowship)
文摘Trivalent europium is a well-known phosphorescent probe widely used in lighting devices and displays,bioassay markers,and anti-counterfeiting phosphors.Double halide perovskite nanocrystals(DHP NCs)have emerged in recent years as attractive host lattices for various luminescent lanthanide dopants owing to the diverse range of trivalent substitutional sites.However,the effect of the DHP NC composition on the Eu^(3+)emission properties has not been systematically investigated.In this work,we prepared a series of DHP NCs containing Eu^(3+)by employing a modified colloidal hot injection procedure.The nanocrystals exhibit finely tunable Eu^(3+)5D0-^(7)F_(J)emission peaks,owing to the different dependence of the electric and magnetic dipole f-f transitions on the coordination symmetry of Eu^(3+).A variation in the values of the Eu^(3+)asymmetry factor,defined as^(7)F_(2)/^(7)F_(1)peak intensity ratio,between 1.0 and 2.5 was observed for different NC compositions,compared to ca.5 for Eu^(3+)in an aqueous solution.The asymmetry factor was also found to be dependent on the Eu^(3+)doping concentration for a given DHP NC host lattice.The sensitivity of the relative intensities of Eu^(3+)emission peaks on the DHP NC composition,together with the dual emission of these NCs,is promising for various anti-counterfeiting applications.
