Bioinspired Perovskite Nanocrystals‐Integrated Photonic Crystal Microsphere Arrays for Information Security

Information security occupies an important position in the era of big data. Attempts to improve the security performance tend to impart them with more additional encryption strategies. Herein, inspired by the wettability feature of Stenocara beetle elytra and signal model of traffic light, a novel array of perovskite nanocrystals (PNs)‐integrated PhC microsphere for information security is presented. The photoluminescent PNs are encapsulated in angle‐independent PhC microspheres to impart them with binary optical signals as coding information. Through the multimask superposition approach, PNs‐integrated PhC microspheres with different codes are placed into fluorosilane‐treated PDMS substrate to form different arrays. These arrays could converge moisture on PhC microspheres in wet environment, which avoids the ions loss of the PNs and effectively prevented mutual contamination. In addition, the fluorescence of the PNs inside PhC microspheres could reversibly quench or recover in response to the environmental moisture. Based on these features, it is demonstrated that the PNs‐integrated PhC microsphere arrays could realize various information encryption modes, which indicate their excellent values in information security fields.