High‐Entropy Perovskite Oxides Integrating Sunlight‐Driven Photochromic and Upconversion Manipulation for Power‐Independent Intrusion Detection Monitoring

Abstract The security monitoring of valuables is a crucial concern to ensure the stable development of human social business activities, scientific research, production, and daily life. The implementation of security precautions has traditionally involved the mere placement of items in safes. However, the formidable task of ascertaining whether valuables have been compromised during storage remains a significant challenge. Photochromic materials are important intelligent substances that can be employed as a potential candidates for security monitoring. However, previous studies have predominantly focused on achieving prominent photochromism by utilizing specific light sources such as ultraviolet, laser, and X‐ray radiation. In light of these existing challenges, a design strategy engaging high entropy is proposed to improve the photochromic performance. By selecting a diverse range of volatile metal elements, the A‐site high entropy is realized within the ABO 3 perovskite structure, enabling the construction of various defects. This results in the successful realization of the material's sensitive response to sunlight, thereby validating the feasibility of the photochromism boosted by a high entropy strategy. The developed photochromic materials for intrusion indication demonstrate the capability to operate autonomously, making it a crucial component in high‐level security monitoring systems and presenting a novel approach toward enhancing security protection in traditional domains.