Controllable decomposition/recrystallization of water-sensitive CsPbBr3 glass ceramics for dynamic anti‐counterfeiting with high security.

This work reports the water induced discoloration phenomenon caused by space-confined effect in borophosphate glass. The CsPbBr 3 nanocrystals grown in borophosphate glass could destroy/recrystallize via the dual-switch process, which is water adhesion and water separation. Finally, an anti-counterfeiting strategy is designed to realize optical information encryption via adopting screen-printing technology. [Display omitted] Due to the sensitivity to water, the all-inorganic CsPbBr 3 nanocrystals have been widely applied in information encryption with spatial dimensions. However, the absence of time-dimension information limits the information capacity for the application of CsPbBr 3. In this work, the CsPbBr 3 nanocrystal was combined with water-sensitive borophosphate glass, achieving decomposing/recrystallization of CsPbBr 3 nanocrystal with multi-dimension. The addition of SiO 2 confirms that the collapse of the borophosphate glass network structure causes the exposure of the CsPbBr 3 nanocrystals. The decomposition and recrystallization mechanism of CsPbBr 3 nanocrystals in glass-ceramics upon encountering water has been verified. Finally, an information encryption strategy, using the mixture of CsPbBr 3 glass ceramic and sodium carboxymethylcellulose as ink, is designed via adopting screen-printing technology, which not only provides a new idea for the preparation of CsPbBr 3 nanocrystals, but also establish a new avenue for the information encryption technology. [ABSTRACT FROM AUTHOR]