Color manipulation from Bi3+-activated CaZnOS under stress with ultra-high efficiency and low threshold for multiple anticounterfeiting
Blue to green emitting mechanoluminescence (ML) is achieved in CaZnOS: Bi3+, Li+, which exhibits about 50 times larger ML intensity than that of the reported strong ML material of ZnS:Cu+. The ML shows an intense emission band peaking at 485 nm, and a red shift of about 9 nm is observed with increasing the stress or friction. In addition, the preferable threshold of CaZnOS: Bi3+, Li+ is below 1 N due to its excellent high strain sensitivity. The depths of the traps responsible for ML are estimated to be in the range of 0.66 - 1.88 eV. The as-prepared CaZnOS: Bi3+, Li+ phosphors were successfully used for the fabrication of homemade ink and flexible thin films, which can be further used for anticounterfeiting and stress mapping. These findings exhibits great potential application in advanced anticounterfeiting technology, visualization of stress distribution for damage diagnosis due to its ultra-high efficiency, low threshold and color tunability.
- This article is part of the themed collection: Journal of Materials Chemistry C HOT Papers