Surficial Host-Guest Responsive CsPbBr Perovskite Nanocrystals for Programmable Multi-Level Information Encryption.

The design of smart stimuli-responsive photoluminescent materials capable of multi-level encryption and complex information storage is highly sought after in the current information era. Here, a novel adamantyl-capped CsPbBr (AD-CsPbBr) perovskite NCs, along with its supramolecular host-guest assembly partner a modified β-CD (mCD), mCD@AD-CsPbBr, are designed and prepared. By dispersing these two materials in different solvents, namely, AD-CsPbBr in toluene, mCD@AD-CsPbBr in toluene, and mCD@AD-CsPbBr in methanol, the three solutions exhibit diverse photoluminescence (PL) turn-on/off or PL discoloration response upon supramolecular stimulus. Based on these responses, a proof-of-principle programmable Multi-Level Photoluminescence Encoding System (MPLES) is established. Three types of four-level and three types of three-level information encoding are achieved by the system. A layer-by-layer four-level information encryption and decryption as well as a two-level encrypted 3D code are successfully achieved.