A stimuli responsive material of perovskite quantum dots composited nano-porous glass

Abstract

Stimuli responsive materials exhibit adaptive behaviors in a dynamic sense according to the conditions in their surrounding environment, which require that their surfaces or structures can be reconstructed. Luminescent CsPbX₃ (X = Cl, Br, I) perovskite quantum dots (QDs) have aroused extensive attention in optoelectronic fields due to their outstanding properties, but they suffer poor resistance to polar solvents like water. Conversely, it would be of great interest if the perovskite QDs could switchably respond to the stimulus of water. In this research, the CsPbX₃ QDs are composited into a transparent nano-porous glass (NPG) by a facile impregnation method. These bulk composite materials possess bright emissions, and are capable of switching colors upon successive stimuli of deionized water and nonaqueous solutions containing bromine ions. An in situ confocal microscope dynamically demonstrates the responsive behavior. Moreover, the bulk composite materials could still give a switched bluish emission even after a duration of several months in water. It is found that the residual chloride ions in the nanosized pores of NPG, which are introduced in the preparation of the blank NPG, play a significant role in stimuli responsive behaviors and long-term resistance to water. This research offers a perspective for fabricating stimuli responsive materials with the ion-exchangeable perovskite QDs.