Xiang Li,Shuhong Xu,Fan Liu,Junfeng Qu,Haibao Shao,Zhuyuan Wang,Yiping Cui,Dayan Ban,Chunlei Wang
The growing demands for optical anti-counterfeiting technology require the development of new environmentally friendly materials with single component, multimodal fluorescence and high stability. Herein, the Bi/Sb codoped Cs2Ag0.1Na0.9InCl6 lead-free double perovskite material is reported as an efficient multimodal luminescence material with excitation-wavelength-dependent emission. When excited by 360 nm UV light, dual-emission is observed at 455 and 560 nm, which comes from the 3P1–1S0 transition of Sb3+ ions and self-trapped excitons (STEs), respectively. Under the 320 nm UV lamp, the microcrystals show only a blue emission centered at 455 nm. Therefore, the Bi/Sb codoped Cs2Ag0.1Na0.9InCl6 double perovskite emits blue and yellow lights under the 320 and 360 nm UV lamp, respectively. Moreover, the obtained double perovskite shows a high PLQY up to 41% and excellent stability against both air and high temperature, which make it a promising anti-counterfeiting material.
You Li,Sai Xu,Qun Zhang,Yuefeng Gao,Xizhen Zhang,Yongze Cao,Hongquan Yu,Xiangping Li,Baojiu Chen
Inorganic lead-free halide perovskites are quite desirable for various applications due to their outstanding optoelectronic performances. However, excitation wavelength-dependent multi-emission in a single luminophore is less reported. In this study, Sb 3+ /Bi 3+ /Er 3+ codoped Cs 2 Ag 0.1 Na 0.9 InCl 6 lead-free double perovskite with upconversion and downshifting luminescence modes has been developed. The double perovskite displays a dual-emission band located at 450 nm and 580 nm under excitation of 355 nm. The blue emission originates from self-trapped excitons (STEs) in [SbCl 6 ] 3- octahedrons, while the yellow emission comes from STEs between states localized in the BiCl 6 and AgCl 6 octahedra. Interestingly, the phosphor’s emission can be dynamically adjusted by excitation wavelength and Sb 3+ doping concentration. Not only that, the phosphor can also generate upconversion green light upon the irradiation of 980 nm lasers. The multi-excitation wavelength characteristics of this perovskite make it very suitable as a material for anti-counterfeiting and encoded information storage, and the excellent temperature stability and moisture resistance of this perovskite also make it more promising.