Light‐Driven Ion Intercalation in Carbon Nitride for High‐Temperature‐Resilient Information Storage and Encryption

Abstract Information storage and encryption systems often suffer from degradation and instability at elevated temperatures. This work introduces a robust ion‐based information storage and encryption system that demonstrates exceptional temperature resistance up to 350 °C, achieved through the immobilization of monoatomic cations (Li + , Na + , and K + ) in carbon nitride via light exposure. By creating electron trap states within the carbon nitride matrix, light exposure enables photo‐charging of the material, transforming it into a capacitor capable of dynamic, reversible color changes for encoding and encrypting information. Notably, the ionic state of the material serves as the foundation for data storage, offering an inherent security feature where trapped electrons are quenched upon air exposure. This encrypted information can be reactivated through light charging. This study establishes a novel paradigm for high‐temperature information storage, using light to control ion movement with precision and security.