Autonomous Signaling and Recording of Electrical and Photodegradation in Polymers

Dielectric polymers are crucial to optoelectronic and spintronic devices. However, electrical stress and/or light irradiation significantly accelerate polymer degradation and can trigger catastrophic failures of many devices, especially in the presence of oxygen. The detection and early warning of these degradations remain challenging. Herein, a class of versatile fluorescent markers is introduced, capable of autonomously signaling and recording both electrical and photodegradation through a visually discernible warning characterized by pronounced fluorescent color changes (up to 195 nm redshift). These changes, induced by chemical reactions between embedded fluorophore indicators and oxygen or radicals generated during degradation, provide quantitative insights into the electrical properties of the polymers. Further, these fluorescent indicators demonstrate superior sensitivity with a limit of detection (LOD) of nmol (several times lower than the best reported values), rapid response (less than 5 s, the highest speed ever reported) to radicals, good memory behavior, excellent generality, and robust resistance to false-positive signals compared to conventional methods, thus providing a robust approach to mitigate or even eliminate the risk of device failure.