Light‐Triggered Sustainable Defect‐Passivation for Stable Perovskite Photovoltaics

• Published in: Advanced materials (Weinheim) Vol. 34; no. 50; pp. e2205338 - n/a
• Main Authors: Shi, Yi‐Ran, Wang, Kai‐Li, Lou, Yan‐Hui, Liu, Gen‐Lin, Chen, Chun‐Hao, Chen, Jing, Zhang, Liang, Wang, Zhao‐Kui
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-12-2022
• Subjects: Configurations; Defects; Dynamic characteristics; Energy conversion efficiency; Healing; Illumination; light‐triggered response; Materials science; Passivity; perovskite solar cells; Perovskites; photostabilities; Photovoltaic cells; Spiropyrans; sustainable passivation; sustainable passivation; photostabilities; perovskite solar cells; light-triggered response
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202205338

The generation of photoinduced defects and freely moving halogen ions is dynamically updated in real time. Accordingly, most reported strategies are static and short‐term, which make their improvements in photostability very limited. Therefore, seeking new passivation strategies to match the dynamic characteristics of defect generation is very urgent. Without newly generated defects, a passivation molecule should exist in the configuration that would not become the initiation sites for defect generation. With newly generated defects, the passivation molecule should transfer into the other configuration that possesses the passivation sites. Herein, a classical photoisomeric molecule, spiropyran, is adopted, whose pre‐ and post‐isomeric forms meet the requirements for two different configurations, to realize the state transition once the photoinduced defects appear during subsequent operation and dynamic capture for continuous renewal of defects. Consequently, spiropyrans work as light‐triggered and self‐healing sustainable passivation sites to realize continuous defect repair. The target devices retain 93% and 99% of their initial power conversion efficiencies after 456 h aging under ultraviolet illumination and 1200 h aging under full‐spectrum illumination, respectively. This work provides a novel concept of sustainable passivation strategy to realize continuous defect‐passivation and film‐healing in perovskite photovoltaics.
A sustainable dynamic passivation strategy by incorporating a photoisomeric molecule is put forward, which greatly enhances the photostability of perovskite photovoltaics. This dynamic strategy pays attention to and well matches the dynamics of defect generation during operation. The characteristics of the changeable molecular structure enable us to cope with defects updated in operation without introducing excess active sites.